coated microcapsules, their use and the consumer product that comprises them

专利摘要:
The present invention relates to coated microcapsules that include a microcapsule formed by a polymeric shell and a liquid core material, encapsulated therein; and a metallic coating with a maximum thickness of 1000 nm, which surrounds these micro-capsules, the metallic coating including particles of a first metal adsorbed in said polymeric shell and a film of a second metal formed on it; and related methods and formulations
公开号:BR112017012363B1
申请号:R112017012363-0
申请日:2015-12-16
公开日:2021-01-19
发明作者:James Paul Hitchcock；Elaine Alice Marie Baxter；Simon Richard Biggs；Olivier Jean Cayre；Zoe Dyter；Lynette Anne Makins Holland；Madhuri Jayant Khanolkar；Raul RODRIGO GOMEZ；Alison Louise Tasker；David William York
申请人:Noxell Corporation；
IPC主号:

专利说明:

FIELD
[001] The present invention relates to microcapsules comprising a liquid core material, processes for their preparation and formulations that include them. More particularly, the present disclosure relates to microcapsules including a liquid core material that can be released in a controlled manner during use. Microcapsules find application in fine fragrance formulations and other consumer products where controlled release of active ingredients is desired. BACKGROUND
[002] The encapsulation of liquid substances and their controlled and targeted distribution are important for the industry. However, the effective encapsulation of liquid substances, especially volatile substances, has proved difficult. Although applications of encapsulation techniques are increasing from year to year, significant difficulties and limitations remain. In particular, the encapsulation of volatile compounds is an area where little progress has been made.
[003] Particular problems are encountered in the encapsulation of perfume oils, which are volatile substances found in fine fragrances and other fragrance formulations. Although the use of microcapsules to encapsulate perfume oils has been proposed, fragrance formulations typically contain polar solvents, such as ethanol, in which the microcapsules are dispersed. These polar solvents can easily penetrate the microcapsule wall, causing perfumed oils to be released prematurely from the microcapsules. It would be desirable to provide microcapsules that follow sheet 1a / 67 r controlled during use, for example, by rupture of the microcapsules during normal human movement.
[004] There is a need in the art for improved microcapsules to encapsulate liquid substances, especially microcapsules that exhibit an improved release profile. In particular, there is a need for microcapsules to encapsulate liquid substances, such as perfume oils, in which the microcapsules are substantially impermeable to polar solvents, such as ethanol, and at the same time, are able to release their contents in a controlled manner during use. There is also a need for improved processes for preparing microcapsules. SUMMARY
[005] Thus, a coated microcapsule is provided comprising:
[006] a microcapsule composed of a polymeric shell and a liquid core material encapsulated therein; and
[007] a metallic coating surrounding said microcapsule;
[008] the metallic coating containing particles of a first metal adsorbed in said polymeric envelope and a film of a second metal formed therein; and where the metallic coating has a maximum thickness of 1000 nm.
[009] Thus, a coated microcapsule is provided comprising:
[0010] a microcapsule formed from a polymeric shell and a liquid core material encapsulated therein; and
[0011] a metallic coating surrounding said microcapsule;
[0012] the metallic coating containing particles of a first metal adsorbed on said polymeric shell and a film of a second metal formed thereon; and where the metallic coating has a maximum thickness of 1000 nm.
[0013] Thus, a process for preparing a coated microcapsule is provided, the process comprising:
[0014] provide a microcapsule formed from a polymeric shell and a liquid core material encapsulated therein; and
[0015] coating said microcapsule with a metallic coating that surrounds said microcapsule, wherein the metallic coating has a maximum thickness of 1000 nm;
[0016] the coating step of said microcapsule comprising:
[0017] adsorbing particles of a first metal onto said polymeric shell; and
[0018] forming a film of a second metal on said particles of the first metal.
[0019] In other respects, the disclosure provides a plurality of coated microcapsules, as well as formulations containing them. Methods of scenting a substrate using a coated microcapsule are also provided.
[0020] The coated microcapsules offer several advantages and benefits. In particular, volatile liquid substances, such as perfume oils, can be encapsulated in microcapsules that are substantially impermeable to polar solvents such as ethanol and, at the same time, can be broken during use. In addition, the preparation processes disclosed herein allow coated micro-capsules to be prepared in an easy manner. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 shows a schematic diagram illustrating a process for preparing an example coated microcapsule. In the process shown, the emulsion mold (a) is converted into an uncoated microcapsule (b) comprising a polymeric shell and a liquid core material. Particles of a first metal are adsorbed on the surface of the microcapsule (c) and a continuous film of a second metal is then applied, producing a coated microcapsule (d). Shown below the schematic diagram are images of optical microscopy (a), transmission electron microscopy (TEM) (b, c) and scanning electron microscopy (SEM) (d) of a microcapsule formed by such a process.
[0022] Figure 2 provides SEM and TEM images obtained at various stages of preparation of a coated microcapsule comprising a poly (methyl methacrylate) shell (PMMA), a hexadecane core and a metallic coating comprising a continuous gold film formed in a layer of platinum nanoparticles. Shown are: (a) an SEM image of the uncoated microcapsules; (b) a TEM image showing the platinum nanoparticles adsorbed on the outer surface of the microcapsules; and (c) an SEM image showing the continuous gold film.
[0023] Figure 3 provides optical, SEM and TEM images obtained in various stages of preparation of a coated microcapsule, the microcapsule comprising a PEMA casing, a toluene core and a metallic coating comprising a continuous silver film formed on a layer of gold nanoparticles stabilized with borohydride. The following are shown: (a) an optical image showing the uncoated microcapsules; (b) TEM images showing the gold nanoparticles stabilized with borohydride adsorbed on the surface of the microcapsules; and (c) an SEM image showing the continuous silver film. Also shown is: (d) an EDX graph that indicates the silver content of the metallic film.
[0024] Figure 4 is a series of TEM images showing metal films of varying thickness.
[0025] Figure 5 groups these data together.
[0026] Figure 6 provides optical, SEM and TEM images obtained at various stages of preparation of a coated microcapsule, the microcapsule being formed by a PMMA shell, a hexyl salicylate core and a metallic coating composed of a layer of platinum nanoparticles stabilized with PVP and a continuous gold film arranged on it. The following are shown: (a) an optical micrograph showing the uncoated microcapsules; (b) a TEM image showing the platinum nanoparticles stabilized with PVP adsorbed on the surface of the microcapsules; and (c) an SEM image showing the gold film on the microcapsules.
[0027] Figure 7a is a graph showing the performance of coated PMMA microcapsules (data points indicated as squares) and uncoated PMMA microcapsules (data points indicated as diamonds) with the Ethanol Stability Test here described. A data point obtained after fracturing the coated PMMA microcapsules at the end of the experiment is also provided (see the data point indicated as a triangle).
[0028] Figure 7b is an SEM image showing the fractured microcapsules.
[0029] Figure 8 is a SEM image of a perfume microcapsule with melamine formaldehyde walls having a complete gold coating.
[0030] Figure 9 is a SEM image of a perfume microcapsule with melamine formaldehyde walls having a gold coating. DESCRIPTION OF VARIOUS MODALITIES Liquid core material
[0031] The coated microcapsules may include a liquid core material encapsulated by a polymeric shell. The term "liquid core material" used in this context refers to a core material made up of one or more components, at least 90% by weight of which are liquid at standard ambient temperature and pressure. The term "standard ambient temperature and pressure" ("STP") refers to a temperature of 25 ° C and an absolute pressure of 100 kPa. Preferably, the liquid core material comprises at least 95% by weight, for example, at least 98% by weight, of one or more components that are liquid at standard ambient temperature and pressure. In some instances, the liquid core material consists of one or more components that are liquid at temperature and standard ambient pressure In some instances, the liquid core material includes a mixture of liquids and a solid, non-limiting examples of which include a mixture of vanillin and scented oils.
The liquid core material may be present in the coated microcapsule in an amount of at least 1% by weight of the microcapsule, preferably in an amount of at least 30% by weight and more preferably in an amount of at least 60% by weight. In some examples, the liquid core material is present in the coated microcapsule in an amount of 10 to 99.9% by weight of the coated microcapsule, alternatively from 40 to 90% by weight of the coated microcapsule, alternatively from 50 to 90% by weight , alternatively from 60 to 80% by weight.
[0033] In some examples, the liquid core material contains one or more components that are volatile. Unless otherwise specified, the term "volatile" in this context refers to materials that are liquid or solid under environmental conditions and that have a measurable vapor pressure at 25 ° C. These materials typically have a vapor pressure greater than about 0.0000001 mm Hg, for example, from about 0.02 mm Hg to about 20 mm Hg, and an average boiling point typically less than about 250 ° C, for example, less than about 235 ° C.
[0034] The liquid core material can consist of a single material or it can be formed by a mixture of different materials. In some instances, the liquid core material includes one or more active ingredients. The coated microcapsules described herein are useful with a wide variety of active ingredients (i.e., "core materials") including, by way of illustration and without limitation, perfumes; rinse aid; insect repellents; silicones; waxes; flavorings; vitamins; fabric softening agents; depilatory agents; skin care agents; enzymes; probiotics; polymer-dye conjugate; clay-dye conjugate; perfume transfer system; sensation agents ("sensates") in one aspect a cooling agent; attractive, in one respect a pheromone; antibacterial agents; dyes; pigments; bleaches; flavorings; sweeteners; waxes; pharmaceutical products; fertilizers; herbicides and mixtures thereof. The core materials of the microcapsule may include materials that alter the rheology or flow characteristics, or prolong the life or stability of the product. Essential oils as core materials can include, for example, by way of example, pine oil, cinnamon oil, clove oil, lemon oil, lime oil, orange oil, peppermint oil and the like. Dyes may include fluorans, lactones, indolyl red, 16B, leuco dyes, all for purposes of illustration and not for limitation. Particularly useful encapsulated materials are volatile fragrances.
[0035] The liquid core material preferably includes one or more components that are soluble in oil. The use of a liquid core material that is soluble in oil will be preferable taking into account, inter alia, the production of microcapsules, which will typically be prepared by a process that involves the use of an oil-in-water emulsion in which the liquid core material is present in the non-aqueous phase (oil). In some instances, the liquid core material is substantially free of water. In particular, the amount of water present in the liquid core material can be less than 5% by weight, for example, less than 1% by weight, of the liquid core material. More preferably, the liquid core material consists of one or more oil-soluble components.
[0036] The liquid core material is preferably free of compounds that are capable of reacting with any of the compounds that are used to form the polymeric shell of the microcapsules. In particular, the liquid core material is preferably free of any polymerizable compounds.
[0037] In some instances, the liquid core material includes a perfume oil formed by one or more perfume raw materials. The term "perfume oil", used in this context, refers to the perfume raw material, or mixture of perfume raw materials, which is used to give an overall pleasant odor profile to the liquid core material. Thus, when different perfume raw materials are present in the liquid core material, this term refers to the overall mixture of perfume raw materials in the liquid core material. The choice of perfume raw materials defines both the intensity of the odor and the character of the liquid core material. The perfume oils used in the coated microcapsules can be relatively simple in their chemical composition, for example, consisting only of a single perfume raw material, or can contain complex mixtures of perfume raw materials, all chosen to provide a desired odor .
[0038] Perfume oil may comprise one or more perfume raw materials with a boiling point below 500 ° C, for example below 400 ° C, for example below 350 ° C. The boiling points of many perfume raw materials are given in, for example, "Perfume and Flavor Chemicals (Aroma Chemicals)" (Perfume and Flavoring Chemicals) by Steffen Arctander (1969) and other manuals known in the art. The one or more perfume raw materials will typically be hydrophobic. The hydrophobicity of a given compound can be defined in terms of its partition coefficient. The term "partition coefficient", in this context, refers to the relationship between the equilibrium concentration of that substance in n-octanol and in water and is a measure of the differential solubility of that substance between these two solvents. Partition coefficients are described in more detail in U.S. 5,578,563.
[0039] The term "logP" refers to the logarithm in base 10 of the partition coefficient. LogP values can be easily calculated using a program called "CLOGP" which is available from Daylight Chemical Information Systems Inc., 30 Irvine, California, USA, or using the Advanced Chemistry Development program (ACD / Labs) 13375P 9 VI 1.02 (© 1994 -2014 ACD / Labs).
[0040] In some examples, perfume oil comprises one or more perfume raw materials having a calculated logP (ClogP) value of about -0.5 or more, for example greater than 0.1, for example greater than 0.5, for example greater than 1.0. In some instances, perfume oil consists of one or more perfume raw materials with a ClogP value greater than 0.1, for example, greater than 0.5, for example greater than 1.0.
[0041] In some examples, perfume oil comprises one or more perfume raw materials selected from aldehydes, esters, alcohols, ketones, ethers, alkenes, nitriles, Schiff bases and mixtures thereof.
[0042] Examples of perfume raw materials of the aldehyde type include, without limitation, alpha-amylcinamaldehyde, anisic aldehyde, decyl aldehyde, lauric aldehyde, methyl-n-nonyl acetaldehyde, methyl octyl acetaldehyde, nonilaldehyde, benzenocarboxaldehyde, neral, geranial, 1,1-dietoxy-3,7-dimethylocta-2,6-diene, 4-isopropylbenzaldehyde, 2,4-dimethyl-3-cyclohexene-1-carboxaldehyde, alpha-methyl-p-isopropylldihydrocinamaldehyde, 3- (3-isopropylphenyl) butanal, alpha-hexylcinamaldehyde, 7-hydroxy-3,7-dimethyloctan-1-al, 2,4-dimethyl-3-cyclohexene-1-carboxaldehyde, octyl aldehyde, phenylacetaldehyde, 2, 4-dimethyl-3-cyclohexene-1 - carboxaldehyde, hexanal, 3,7-dimethyloctanal, 6,6-dimethylbicyclo [3.1.1] hept-2-ene-2-butanal, nonanal, octanal, 2-nonenal undecenal, 2-methyl-4- (2,6,6-trimethyl-1-cyclohexenyl-1) -2-butenal, 2,6-dimethyloctanal, 3- (p-isopropylphenyl) propionaldehyde, 3-phenyl-4 -pentenal citronelal, o / p-ethyl-alpha, alpha, 9-decennial, dimethyldihydrocinamaldehyde, p-isobutyl-alpha-methylhydrocinamaldehyde , cis-4-decen-1-al, 2,5-dimethyl-2-ethylen-4-hexenal, trans-2-methyl-2-butenal, 3-methylnonanal, alpha-sinensal, 3-phenylbutanal, 2 , 2-dimethyl-3-phenylpropionaldehyde, mt-butyl-alpha-methyldihydrocinnamic aldehyde, geranyl oxyacetaldehyde, trans-4-decen-1-al, methoxytronelal and mixtures thereof.
[0043] Examples of ester-based perfume raw materials include, without limitation, allyl cyclohexane-propionate, allyl-heptanoate, allyl-amyl-glycolate, allyl-caproate, amyl-acetate (n-pentyl-acetate), amylpropionate, benzyl acetate, benzyl propionate, benzyl salicylate, cis-3-hexenyl acetate, citronellyl acetate, citronellyl propionate, cyclohexyl salicylate, dihydro-isojasmonate, dimethyl benzylcarbyl acetate, acetate ethyl, ethyl acetoacetate, ethyl butyrate, ethyl-2-methyl butyrate, ethyl-2-methyl pentanoate, fenchyl acetate (1,3,3-trimethyl-2-norbornanyl acetate), tricyclodecenyl acetate, propionate of tricyclodecenyl, geranyl acetate, cis-3-hexenyl isobutyrate, hexyl acetate, cis-3-hexenyl salicylate, n-hexyl salicylate, isobornyl acetate, linalyl acetate, cyclo-butyl acetate hexyl, (-) - L-menthyl acetate, ot-butylcyclohexyl acetate, methyl benzoate, methyl dihydro isojasmonate, ac alpha-methylbenzyl etate, methyl salicylate, 2-phenylethyl acetate, pre-nyl acetate, cedryl acetate, cyclabut, phenethyl phenylacetate, terpinyl format, citronyl anthranylate, tricycle [5.2.1.0-2.6] ethyl decane-2-carboxylate, n-hexyl ethyl acetoacetate, 2-t-butyl-4-methyl cyclohexyl acetate, formic acid, 3,5,5-trimethylhexyl ester, phenethyl crotonate, cyclogeranyl acetate , geranyl crotonate, ethyl geranate, geranyl isobutyrate, 3,7-dimethyl-ethyl 2-noninoate-2,6-octadiene acid, citronellar valerate, 2-hexenylcyclopentanone, cyclohexyl anthranylate, L-citronellil tiglate, butyl tiglate, pentyl tiglate, geranyl caprylate, 9-decenyl acetate, 2-isopropyl-5-methylhexyl butyrate, n-pentyl benzoate, 2-methylbutyl benzoate (and mixtures with pentyl benzoate), dimethyl benzyl carbinyl propionate, dimethyl benzyl carbine acetate, trans-2- salicylate hexenyl, dimethyl benzyl carbinyl isobutyrate, 3,7-dimethyloctyl formate, rhodinyl formate, rhodinyl isovalerate, rhodinyl acetate, rhodinyl butyrate, rhodinyl propionate, cyclohexylethyl acetate, neryl butyrate tetrahydrogeranyl, myrcenyl acetate, 2,5-dimethyl-2-ethenyl-hex-4-enoic acid, methyl ester, 2,4-dimethylcyclohexane-1-methyl acetate, food acetate, isobutyrate linalyl, 6-methyl-5-heptenyl-1 acetate, 4-methyl-2-pentyl acetate, n-pentyl 2-methylbutyrate, propyl acetate, isopropenyl acetate, isopropyl acetate, 1-methylcyclohex acid -3-eno-carboxylic, methyl ester, propyl tiglate, cyclopent-3-enyl-1-propyl / isobutyl acetate (alphavinyl), butyl 2-furoate, ethyl 2-pentenoate, (E) 3-pentenoate methyl, 3-methoxy-3-methylbutyl acetate, n-pentyl crotonate, n-pentyl isobutyrate, propyl format, furfuryl butyrate, methyl angelate, methyl pivalate, cap prenyl roate, furfuryl propionate, diethyl malate, isopropyl 2-methylbutyrate, dimethyl malonate, bornyl formate, styryl acetate, 1- (2-furyl) -1-propanone, 1-citronyl acetate, acetate 3,7-dimethyl-1, 6 nonadien-3-yl, nerile crotonate, dihydromyrcenyl acetate, tetrahydromyrcenyl acetate, lavandulyl acetate, 4-cyclooctenyl isobutyrate, cyclopentyl isobutyrate, cyclopentyl acetate 3-methyl-3-butenyl, allyl acetate, geranyl formate, cis-3-hexenyl caproate and mixtures thereof.
[0044] Examples of alcohol-based perfume raw materials include, without limitation, benzyl alcohol, beta-gamma-hexenol (2-hexen-1-ol), cedrol, citronelol, cinnamic alcohol, p-cresol, humic alcohol, dihydromyrcenol, 3,7-dimethyl-1-octanol, dimethyl benzyl carbinol, eucalyptol, eugenol, phenolic alcohol, geraniol, hydratopic alcohol, isononic alcohol (3,5,5-trimethyl-1-hexanol), linalool, methyl-chavicol (estragol), methyl-eugenol (eugenyl methyl ether), nerol, 2-octanol, patchouli alcohol, phenyl hexanol (3-methyl-5-phenyl-1-pentanol), phenethyl alcohol, alpha-terpineol, te - tra-hydrolinalool, tetrahydromyrcenol, 4-methyl-3-decen-5-ol, 1-3,7-dimethyloctane-1-ol, 2- (furfuryl-2) -heptanol, 6,8-dimethyl-2 -nonanol, ethyl norbornyl cyclohexanol, beta-methylcyclohexane ethanol, 3,7-dimethyl- (2), 6-octen (adien) 1-ol, trans-2-undecen-1-ol, 2-ethyl- 2-prenyl-3-hexenol, isobutylbenzylcarbinol, dimethylbenzylcarbinol, ocimenol, 3,7-dimethyl-1,6-nonadien-3-ol (cis and trans), tetrahydromyrcenol, alpha-te rpineol, 9-decenol-1,2- (2-hexenyl) -cyclopentanol, 2,6-dimethyl-2-heptanol, 3-methyl-1-octen-3-ol, 2,6-dimethyl-5-hepten 2-ol, 3,7,9-trimethyl-1,6-decadien-3-ol, 3,7-dimethyl-6-nonen-1-ol, 3,7-dimethyl-1-octin-3-ol, 2,6-dimethyl-1, 5,7-octatrienol-3, dihydromyrcenol, 2,6, trimethyl-5,9-undecadienol, 2,5-dimethyl-2-propyl-hex-4-enol-1, (Z) 3-hexenol, o, m, p-methyl-phenylethanol, 2-methyl-5-phenyl-1-pentanol, 3-methylphenethyl alcohol, para-methyl dimethyl benzyl carbinol, methyl benzyl carbinol, p-methylphenylethanol, 3 , 7-dimethyl-2-octen-1-ol, 2-methyl-6-methylene-7-octen-4-ol, and mixtures thereof.
[0045] Examples of perfume raw materials of the ketone type include, without limitation, oxacycloheptadec-10-en-2-one, benzylacetone, benzophenone, L-carvone, cis-jasmine, 4- (2,6,6- trimethyl-3-cyclohexen-1-yl) -but-3-en-4-one, ethyl amyl ketone, alpha-ionone, beta-ionone, ethane-, octahydro-2,3,8,8 -tetramethyl-2-acetonephthalene, alpha-irone, 1- (5,5-dimethyl-1-cyclohexen-1-yl) -4-penten-1-one, 3-nonanone, ethyl hexyl ketone, menthol, 4 -methyl-acetophenone, gamma-methyl ionone, methyl pentyl ketone, methyl heptenone (6-methyl-5-hepten-2-one), methyl heptyl ketone, methyl hexyl ketone, delta muscenone, 2-octanone, 2-pentyl-3 -methyl-2-cyclopenten-1-one, 2-heptylcyclopentanone, alpha-methionone, 3-methyl-2- (trans-2-pentenyl) - cyclopentenone, octenyl cyclopentanone, n-amylcyclopentenone, 6-hydroxy acid lactone-3 , 7-dimethyloctanoic, 2-hydroxy-2-cyclohexen-1-one, 3-methyl-4-phenyl-3-buten-2-one, 2-pentyl-2,5,5-trimethylcyclopentanone, 2-cyclopentylcyclopentanol -1,5-methyl-hexan-2-one, gamma-dodecalact ona, delta-dodecalactone, gamma-nonalactone, delta-nonalactone, gamma-octalactone, delta-undecalactone, gamma-undecalactone, and mixtures thereof.
[0046] Examples of ether-type perfume raw materials include, without limitation, p-cresyl methyl ether, 4,6,6,7,8,8-hexamethyl- 1,3,4,6,7,8- hexahydrocyclopenta (G) -2-benzopyran, beta-naphthyl methyl ether, methyl isobutenyl tetrahydropyran, 5-acetyl-1,1,2,3,3,6-hexamethylindane (fantolide), 7-acetyl-1, 3,3,4,4,6 Hexamethyltetralin (toalide), 2-phenylethyl-3-methylbut-2-enyl ether, ethyl geranyl ether, phenylethyl isopropyl ether and mixtures thereof.
[0047] Examples of perfume raw materials of the alkene type include, without limitation, allo-ocimene, camphene, beta-karyophylene, cadainen, diphenylmethane, d-limonene, limolene, beta-myrcene, para-cymene, 2- alpha-pinene, beta-pinene, alpha-terpinene, gamma-terpinene, terpineolene, 7-methyl-3-methylene-1,6-octadiene and mixtures thereof.
[0048] Examples of nitrile-type perfume raw materials include, without limitation, 3,7-dimethyl-6-octenonitrile, 3,7-dimethyl-2 (3), 6-nonadienonitrile, (2E, 6Z) -2 , 6- nonadienonitrile, n-dodecane-nitrile, and mixtures thereof.
[0049] Examples of Schiff bases-type perfume raw materials include, without limitation, citronellil nitrile, nonanal / methyl anthranilate, methyl ester of N-octylene anthranilic acid, hydroxytitronalate / methyl anthranilate, aldehyde cyclamen / anthranylate methyl, methoxy-phenylpropanal / methyl anthranilate, ethyl p-aminobenzoate / hydroxycitroneal, citral / methyl anthranilate, 2,4-dimethylcyclohex-3-enocarbaldehyde methyl anthranylate, hydroxycitralal-indole and mixtures thereof.
[0050] Non-limiting examples of other perfume raw materials useful in this context include pro-fragrances, such as acetal pro-fragrances, ketal pro-fragrances, ester pro-fragrances, hydrolysable inorganic-organic fragrances and mixtures of same. Fragrance materials can be released from fragrances in a variety of ways. For example, the fragrance can be released as a result of simple hydrolysis, or by a shift in an equilibrium reaction, or by a change in pH, or by enzymatic release.
[0051] In some examples, perfume oil comprises one or more of the perfume raw materials mentioned in the lists above. In some instances, perfume oil comprises a plurality of perfume raw materials cited in the above lists.
[0052] In some examples, the liquid core material comprises one or more perfume oils of natural origin. In some examples, the liquid core material includes one or more perfume oils selected from musk oil, civet, castoreum, ambergris, nutmeg extract, cardamom extract, ginger extract, cinnamon extract, patchouli oil, oil geranium, orange oil, tangerine oil, orange flower extract, cedar, vetiver, lavender, ylang extract, tuberose extract, sandalwood oil, bergamot oil, rosemary oil, mint oil, mint oil pepper, lemon oil, lavender oil, citronella oil, chamomile oil, clove oil, sage oil, neroli oil, laudanum oil, eucalyptus oil, verbena oil, mimosa extract, narcissus extract, carrot seed extract, jasmine extract, olibanum extract, rose extract and mixtures thereof. One or more of these perfume oils can be used with one or more of the perfume raw materials mentioned above.
[0053] Perfume oil can be present in the liquid core material in an amount of 0.1 to 100% by weight of the liquid core material. In some instances, the liquid core material essentially consists, for example, of a perfume oil. In some examples, perfume oil is present in the liquid core material in an amount of at least 10% by weight of the liquid core material, preferably at least 20% by weight and more preferably at least 30% by weight. In some examples, perfume oil is present in the liquid core material in an amount of 80100% by weight of the liquid core material, alternatively less than 80% by weight of the liquid core material, alternatively less than 70% by weight, alternatively less than 60 % by weight. In some examples, perfume oil is present in an amount of 10 to 50% by weight of the liquid core material, more preferably 15 to 30%. Preferred liquid core materials contain from 10 to 80% by weight of a perfume oil, preferably from 20 to 70%, more preferably from 30 to 60%.
[0054] The liquid core material may contain one or more components in addition to perfume oil. For example, the liquid core material may contain one or more diluents. Examples of diluents include mono-, di- and tri-esters of C4-C24 fatty acids and glycerin, isopropyl myristate, soybean oil, hexadecanoic acid, methyl ester, isodode-canon and mixtures thereof. When present, diluents are preferably present in the liquid core material in an amount of at least 1% by weight of the liquid core material, e.g. From 10 to 60% by weight of the liquid core material. When present, the diluents are preferably in the liquid core material in an amount of at least 1% by weight of the liquid core material, for example, from 10 to 60% by weight of the liquid core material. Polymeric casing
[0055] The liquid core material is encapsulated by a polymeric shell. The coated microcapsules can be prepared by first forming the polymeric shell around the liquid core material to form an uncoated microcapsule, and subsequently forming the metallic coating. The term "uncoated microcapsule" used herein refers to the microcapsule that comprises the liquid core material prior to coating with the metallic layer.
[0056] The polymeric shell may contain one or more polymeric materials. For example, the polymeric shell can include one or more polymers chosen from synthetic polymers, naturally occurring polymers and combinations thereof. Examples of synthetic polymers include, without limitation, nylon, polyethylenes, polyamides, polystyrenes, polyisoprene, polycarbonates, polyesters, polyureas, polyurethanes, polyolefins, polysaccharides, epoxy resins, vinyl polymers, polyacrylates and combinations thereof. Examples of synthetic polymers include, without limitation, silk, wool, gelatin, cellulose, alginate, proteins and combinations thereof. The polymeric shell can comprise a homopolymer or a copolymer (for example, a block copolymer or a graft copolymer).
[0057] In some examples, the polymeric enclosure includes a polyacrylate, for example, poly (methyl methacrylate) (PMMA) or poly (ethyl methacrylate) (PEMA). The polyacrylate can be present in an amount of at least 5%, at least 10%, at least 25%, at least 30%, at least 50%, at least 70% or at least 90% by weight of the polymeric shell.
[0058] In some examples, the polymeric shell includes a random polyacrylate cup-polymer. For example, the random polyacrylate copolymer can include: an amine content of 0.2 to 2.0% by weight of the total mass of polyacrylate; a carboxylic acid content of 0.6 to 6.0% by weight of the total mass of polyacrylate; and a combination of an amine content of 0.1 to 1.0% and a carboxylic acid content of 0.3 to 3.0% by weight of the total mass of polyacrylate.
[0059] In some examples, the microcapsule shell includes a reaction product from a first mixture in the presence of a second mixture containing an emulsifier, the first mixture containing a reaction product from i) an oil-soluble or dispersible amine with ii ) a multifunctional acrylate or methacrylate monomer or oligomer, an oil-soluble acid and an initiator, the emulsifier containing a water-soluble or dispersible acrylic acid-alkyl acid copolymer, an alkali or alkaline salt and optionally an aqueous phase initiator. In some examples, said amine is selected from the group consisting of aminoalkyl acrylates, aminoalkylalkyl acrylates, dialkylaminoalkyl acrylates, aminoalkyl methacrylates, alkylaminoaminoalkyl methacrylates, tertiary-alkylamine methacrylates, tertiary acrylates, methacrylates and methacrylates diethylaminoethyl methacrylates, dimethylaminoethyl methacrylates, dipropylaminoethyl methacrylates and mixtures thereof. In some examples, said amine is an aminoalkyl acrylate or aminoalkyl methacrylate.
[0060] In some examples, the polymeric casing includes a reaction product of an amine with an aldehyde. For example, the polymeric shell may include a reaction product selected from urea crosslinked with formaldehyde or glutaraldehyde; formaldehyde crosslinked melamine; gelatin-polyphosphate coacervates, optionally cross-linked with glutaraldehyde; gelatin-gum arabic coacervates; cross-linked silicone fluids; polyamines reacted with polyisocyanates; acrylate monomers polymerized through polymerization by free radicals, and mixtures thereof. In some examples, the polymeric shell includes a reaction product selected from urea-formaldehyde (i.e., the reaction product cross-linked urea with formaldehyde) and melamine resin (i.e., melamine cross-linked with formaldehyde).
[0061] In some examples, the polymeric shell includes gelatin, optionally in combination with one or more additional polymers. In some examples, the polymeric shell includes gelatin and polyurea.
[0062] The polymeric shell may contain one or more components in addition to the one or more wall-forming polymers. Preferably, the polymeric shell further includes an emulsifier. Thus, and as described in greater detail below, encapsulation of the liquid core material can be achieved by providing an oil-in-water emulsion in which the droplets of the oil (non-aqueous) phase including the liquid core material are dispersed in a continuous aqueous phase, and then forming a polymeric envelope around the droplets. Such processes are typically carried out in the presence of an emulsifier (also known as a stabilizer), which stabilizes the emulsion and reduces the likelihood of microcapsule aggregation during the formation of the polymeric shell. Emulsifiers usually stabilize the emulsion by orienting themselves at the oil / water phase interface, thus establishing a steric and / or charged boundary layer around each drop. This layer serves as a barrier to other particles or droplets, preventing their intimate contact and coelescence, thus maintaining a uniform droplet size. Since the emulsifier will typically be retained in the polymeric shell, the polymeric shell of the microcapsules can contain an emulsifier as an additional component. The emulsifier can be adsorbed and / or absorbed into the polymeric shell of the microcapsules.
[0063] The emulsifier can be a polymer or a surfactant. The emulsifier can be a nonionic, cationic, anionic, zwitterionic or amphoteric emulsifier. Examples of suitable emulsifiers include, without limitation, cetyl trimethylammonium bromide (CTAB), poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP), poly (acrylic acid) (PAA), poly (methacrylic acid) (PMA ), dodecyldimethyl ammonium bromide (DDAB), sodium dodecyl sulfate (SDS) and poly (ethylene glycol). In some examples, the emulsifier is selected from cetyl trimethylammonium bromide, poly (vinyl alcohol) and poly (vinylpyrrolidone).
[0064] Uncoated microcapsules can be formed by emulsifying the liquid core material in droplets and forming a polymeric envelope around the droplets. Microencapsulation of the liquid core material can be performed using a variety of methods known in the art, including coacervation methods, in situ polymerization methods and interfacial polymerization methods. Such techniques are known in the art (see, for example, "Microencap-sulation: Methods and Industrial Applications", Edited by Benita and Simon, Marcel Dekker, Inc., 1996; US 2,730,456; US 2,800,457; US 2,800,458; US 4,552,811; US 6,592,990; and US 2006/0263518).
[0065] In some examples, microcapsules are prepared by a coacervation method that involves the oil-in-water emulsion followed by solvent extraction. Such procedures are known in the art (see, for example, Loxley et al., Journal of Colloid and Interface Science, vol. 208, pp. 49-62, 1998) and involve the use of a non-aqueous phase containing a material polymeric which is capable of forming a polymeric envelope, a poor solvent for the polymeric material and a cosolvent which is a good solvent for the polymeric material. The non-aqueous and aqueous phases are emulsified, forming an oil-in-water emulsion containing droplets of the non-aqueous phase dispersed in the continuous aqueous phase. The cosolvent is then partially or totally extracted from the non-aqueous phase, causing the polymeric material to precipitate around the poor solvent, thus encapsulating the poor solvent.
[0066] Uncoated microcapsules can be prepared by the following method: (i) providing a non-aqueous phase containing a polymeric material that is capable of forming a polymeric shell, a liquid core material that is a poor solvent for the polymeric material and a co-solvent which is a good solvent for the polymeric material; (ii) providing an aqueous phase; (iii) emulsifying the non-aqueous phase and the aqueous phase to form an emulsion containing droplets of the non-aqueous phase dispersed within the aqueous phase; and (iv) extracting at least a part of the co-solvent from the non-aqueous phase so that the polymeric material precipitates around droplets containing the liquid core material, thus encapsulating the liquid core material.
[0067] In some examples, the polymeric material includes a polyacrylate, for example, poly (methyl methacrylate) (PMMA), poly (ethyl methacrylate) (PEMA) or a combination of these. In some examples, the polymeric material consists of poly (methyl methacrylate) (PMMA) or poly (ethyl methacrylate) (PEMA).
[0068] Preferably, the polymeric material has an average molecular weight by weight of at least 10 kDa, more preferably at least 50 kDa, more preferably at least 100 kDa. Preferably, the polymeric material has a weight average molecular weight of 10 to 1000 kDa, more preferably 50 to 800 kDa, more preferably 100 to 600 kDa.
[0069] With respect to the chemical composition of the non-aqueous phase, the liquid core material is preferably present in an amount of 0.5 to 50%, preferably 1 to 45%, and more preferably 3 to 40% by weight of the phase not watery. The polymeric material is preferably present in the non-aqueous phase in an amount of 0.5 to 15%, preferably 1 to 10%, and more preferably 2 to 8% by weight of the non-aqueous phase. The cosolvent is preferably present in an amount of 40 to 98%, preferably 50 to 98%, and more preferably 60 to 95% by weight of the non-aqueous phase. In some examples, the non-aqueous phase consists of the liquid core material, the polymeric material and the cosolvent.
[0070] In some examples, the co-solvent is a volatile material, for example, dichloromethane (DCM), and is extracted from the non-aqueous phase by evaporation. In this case, the precipitation of the polymeric material can be aided by heating the emulsion to promote the evaporation of the co-solvent. For example, the method can be carried out at a temperature of at least 30 ° C.
[0071] Preferably, at least one of the aqueous and non-aqueous phases comprises an emulsifier. More preferably, the aqueous phase comprises an emulsifier. Examples of emulsifiers include, without limitation, poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidine) (PVP), cetyl trimethylammonium bromide (CTAB) and mixtures thereof. In some examples, the emulsifier is present in an amount of 0.01 to 50% by weight of the aqueous phase, preferably from 0.5 to 30%, and more preferably from 0.1 to 10% by weight.
[0072] In some examples, the polymeric shell is formed by a process of interfacial polymerization.
[0073] For example, the polymeric shell can be prepared by an interfacial polymerization process which involves the use of a non-aqueous phase comprising the liquid core material and one or more oil-soluble monomers; and an aqueous phase comprising one or more water-soluble monomers and an emulsifier. The non-aqueous and aqueous phases are emulsified to form an emulsion containing droplets of the non-aqueous phase dispersed within the aqueous phase. The monomers are then polymerized, typically by heating, with the polymerization taking place at the interface between the non-aqueous phase and the aqueous phase.
[0074] Alternatively, the polymeric shell can be obtained by interfacial polymerization of a prepolymer. Such processes can be used to prepare a variety of different polymeric materials. For example, a polymeric shell containing a polyacrylate, polyamine or polyurea material can be prepared by this process.
[0075] Preferably, the polymeric material includes a polyacrylate. In some examples, the polymeric shell includes a polyacrylate and can be obtained by interfacial polymerization of a prepolymer, in which the prepolymer is obtained by reacting a mixture comprising: (i) an aminoalkyl acrylate monomer, an aminoalkyl methacrylate monomer or a mixture of these; and (ii) an acrylate monomer, a methacrylate monomer, an acrylate oligomer, a methacrylate oligomer or a mixture thereof.
[0076] More preferably, the polymeric shell is prepared by a process comprising:
[0077] (i) providing a non-aqueous phase comprising the liquid core material, an amine monomer, a multifunctional acrylate or methacrylate monomer or oligomer, an acid and a free radical initiator;
[0078] (ii) reacting the amine monomer with the multifunctional acrylate or methacrylate monomer or oligomer to form a prepolymer;
[0079] (iii) providing an aqueous phase containing an emulsifier, an alkali or alkaline salt and optionally a free radical initiator;
[0080] (iv) contacting the non-aqueous phase with the aqueous phase under conditions such that an emulsion is formed containing droplets of the non-aqueous phase dispersed in the aqueous phase; and
[0081] (v) polymerize the prepolymer to form a polymeric envelope that encapsulates the liquid droplets.
[0082] The amine monomer is an oil-soluble or oil-dispersible amine monomer, more preferably an aminoalkyl acrylate or aminoalkyl methacrylate. In some examples, the amine monomer is selected from aminoalkyl acrylates, alkylaminoalkyl acrylates, dialkylaminoalkyl acrylates, aminoalkyl methacrylates, alkylaminoaminoalkyl methacrylates, alkylacrylamethyl methacrylate, methacrylacrylate, methylacrylate, methacrylacrylate, methylacrylate dimethylaminoethyl methacrylates, dipropylaminoethyl methacrylates and mixtures thereof. Preferred ammonium monomers are diethylaminoethyl methacrylate, di-methylaminoethyl methacrylate, t-butylaminoethyl methacrylate and mixtures thereof. Most preferably, the amine is t-butylaminoethyl methacrylate and the acrylate or multifunctional methacrylate monomer or oligomer is a hexafunctional aromatic urethane acrylate oligomer.
[0083] In the above process, an aqueous phase containing an emulsifier and an alkali or alkaline salt is used. Examples of emulsifiers include, without limitation, poly (vinyl alcohol) (PVA), poly (pyrrolidine vinyl) (PVP), cetyl trimethylammonium bromide (CTAB) and mixtures thereof. In some examples, the alkali or alkaline salt is sodium hydroxide.
[0084] The interfacial polymerization process is preferably carried out in the presence of a free radical initiator. Examples of suitable free radical initiators include azo, peroxide, alkyl peroxides, dialkyl peroxides, peroxyesters, peroxycarbonates, peroxycarbonates and peroxydicarbonates. In some examples, the free radical initiator is selected from 2,2'-azobis- (2,4-dimethylpentanonitrile), 2,2'-azobis- (2-methyl-butyronitrile) and mixtures thereof. A free radical initiator can be present in the aqueous phase, the non-aqueous phase, or both.
[0085] In some examples, microcapsules are prepared by an in situ polymerization process. Such processes are known in the art and generally involve the preparation of an emulsion including droplets of the liquid core material dispersed in a continuous phase containing a precursor material that can be polymerized to form a polymeric shell; and polymerizing the precursor material to form a polymeric shell, thus encapsulating the liquid droplets. The polymerization process is similar to that of interfacial polymerization processes, except that no precursor material for the polymeric shell is included in the liquid core material in in situ polymerization processes. Thus, polymerization occurs only in the continuous phase, instead of on each side of the interface between the continuous phase and the core material.
[0086] Examples of precursor materials for the polymeric shell include, without limitation, prepolymeric resins, such as urea resins, melamine resins, acrylate esters and isocyanate resins. Preferably, the polymeric shell is formed by the polymerization of a precursor material selected from: melamine-formaldehyde resins; urea-formaldehyde resins; monomeric or low molecular weight polymers of methylol melamine; monomeric or low molecular weight polymers of dimethylol urea or methylated dimethylolurea; and partially methylated methylol melamine.
[0087] The use of melamine-formaldehyde resins or urea-formaldehyde resins as a precursor material is particularly preferred. Procedures for preparing microcapsules composed of such precursor materials are known in the art (see, for example, U.S. 3,516,941, U.S. 5,066,419 and U.S. 5,145,842). The capsules are made first by emulsifying the liquid core material as small droplets in an aqueous phase containing the melamine-formaldehyde or urea-formaldehyde resin and then allowing the polymerization reaction to proceed together with precipitation at the oil-water interface.
[0088] In some examples, microcapsules can be prepared by a process that comprises:
[0089] (i) providing a non-aqueous phase containing the liquid core material;
[0090] (ii) providing an aqueous phase containing a melamine-formaldehyde prepolymer (for example, a partially methylated methylol melamine resin);
[0091] (iii) emulsify the non-aqueous and aqueous phases to form an emulsion containing droplets of the non-aqueous phase dispersed in the aqueous phase; and
[0092] (iv) condensing the melamine-formaldehyde prepolymer, thus forming a melamine-formaldehyde polymer that precipitates from the aqueous phase and encapsulates said droplets.
[0093] The polymerization process is preferably carried out using an emulsifier, which is preferably present in the aqueous phase. As an illustration, an anionic emulsifier (for example, butyl acrylate and acrylic acid copolymers) and / or a neutral emulsifier (for example PVP) can be used.
[0094] Condensation of the melamine-formaldehyde prepolymer can be initiated by, for example, lowering the pH of the emulsion. The pH of the emulsion can be adjusted using a base as appropriate. Examples of suitable bases include alkali metal hydroxides (for example, sodium hydroxide), ammonia and triethanolamine. In each of the emulsion processes described herein, emulsification can be carried out using any suitable mixing device known in the art. For example, a homogenizer, a colloid mill, an ultrasonic dispersion device or an ultrasonic emulsifier can be used. Preferably, a homogenizer is used.
[0095] The resulting polymeric shell may have a thickness greater than 0.5 nm, preferably greater than 1 nm, and more preferably greater than 2 nm. Typically, the polymeric shell will have a thickness of less than 2000 nm, preferably less than 1500 nm, and more preferably less than 1100 nm. The microcapsules preferably have a polymeric shell with a thickness of 1 to 2000 nm, such as 2 to 1100 nm. Factors such as the concentration of the casing-forming material in the emulsion will dictate the thickness of the polymeric casing.
[0096] The size of the microcapsules can be controlled by changing factors such as the stirring speed and the shape of the stirring blade or rotor paddle of the agitator or homomixer ("homomixer") used during the emulsification step of the microencapsulation process or adjusting the reaction rate by changing the polymerization conditions (eg temperature and reaction time) for the polymeric material. In particular, the size of the microcapsules can be controlled by regulating the stirring speed, which in turn regulates the size of the droplets of the liquid core material in the emulsion. Metallic Coating
[0097] The coated microcapsules may further comprise a metallic coating that surrounds the microcapsules. The metallic coating has a maximum thickness of 1000 nm and contains particles of a first metal adsorbed on the polymeric shell and a film of a second metal disposed on said particles. The film of the second metal provides a continuous coating that surrounds the surface of the microcapsule. Preferably, the thickness of the metallic coating is substantially uniform throughout the coating.
[0098] The particles of the first metal are preferably nano-particles. The term "nanoparticles", in this context, refers to particles with a particle size of 1 to 200 nm. Preferably, metallic nanoparticles have a particle size of less than 100 nm, for example, less than 50 nm. More preferably, the metallic nanoparticles have a particle size of less than 10 nm, more preferably less than 5 nm, and more preferably less than 3 nm. In this regard, the use of smaller metallic nanoparticles can result in the formation of a thinner metallic coating. Nanoparticles will typically have a spheroidal geometry, but they can exist in more complex shapes, such as sticks, stars, ellipsoids, cubes or sheets ("sheets").
[0099] In some examples, nanoparticles are composed of gold, silver, copper, tin, cobalt, tungsten, platinum, palladium, nickel, iron or aluminum, or mixtures thereof. In some examples, nanoparticles include an alloy of two or more metals, for example, an alloy of two or more metals selected from gold, silver, copper, tin, cobalt, tungsten, platinum, palladium, nickel, iron and aluminum. In some examples, nanoparticles include a metal oxide, for example, aluminum oxide or iron oxide. In some examples, nanoparticles are composed of core-shell particles containing a core of a first metal or metal oxide surrounded by a shell of a second metal or metal oxide. In some examples, nanoparticles consist of a single metal.
[00100] As described in more detail below, the film of the second metal is preferably applied by an autocatalytic coating procedure ("electroless plating") which is catalyzed by the particles of the first metal. Thus, it is preferable that the particles of the first metal include a metal that catalyzes the autocatalytic coating process.
[00101] The first metal can be selected from the transition metals and metals in the p-block, for example, a metal selected from the metals listed in Groups 9 to 14 of the Periodic Table, in particular a metal selected in Groups 10, 11 and 14. Preferably, the first metal is a metal selected from nickel, palladium, platinum, silver, gold, tin and combinations thereof. Preferably, the first metal comprises platinum, silver, gold or a mixture thereof.
[00102] The first and second metals can be the same or different. Preferably, the second metal is different from the first metal.
[00103] The second metal is preferably a metal that is capable of being deposited through an autocatalytic coating process (electroless). The second metal can be a transition metal, for example, a metal selected from the metals listed in Groups 9 to 14 of the Periodic Table, in particular a metal selected in Groups 10 and 11. Preferably, the second metal is a selected metal between silver, gold, copper and combinations thereof.
[00104] In some examples, the first metal is selected from Au, Pt, Pd, Sn, Ag and combinations thereof; and the second metal is selected from Au, Ag, Cu, Ni and combinations thereof.
[00105] In some examples, the first metal is selected from Au, Pt, Pd, Sn, Ag and combinations of them (for example, Sn / Ag) and the second metal is Au. In some examples, the first metal is selected from Sn, Pt, Ag, Au and combinations of them (for example, Pt / Sn) and the second metal is Ag. In some examples, the first metal is selected from Sn, Ag, Ni and combinations thereof (for example, Sn Ni or Sn Ag) and the second metal is Cu. In some examples, the first metal is selected from Sn, Pd, Ag and combinations of them (for example, Sn / Pd) and the second metal is Ni.
[00106] In some examples, the first metal is Pt and the second metal is Au; the first metal is Au and the second metal is Ag; or the first metal is Au and the second metal is Cu. Most preferably, the first metal is Au and the second metal is Ag; or the first metal is Pt and the second metal is Au.
[00107] The particles of the first metal are preferably adsorbed onto the polymeric shell in the form of a discontinuous layer, so that, prior to the application of the metallic film, the surface of the polymeric shell comprises regions that include adsorbed metallic particles. and regions in which adorbed metal particles are absent. The metal particles can be distributed on the surface of the polymeric shell substantially uniformly.
[00108] The thickness of the film of the second metal can vary with the density of the particles of the first metal adsorbed on the polymeric shell of the microcapsule, with a higher density of particles of the first metal typically encouraging the growth of a thinner film. In some examples, the particles are deposited on the polymeric shell at a density such that said particles cover from 0.1 to 80% of the surface area of the polymeric shell, for example from 0.5 to 40% of the surface area of the polymeric shell , for example from 1 to 4% of the surface area of the polymeric shell. The density of the particles in the polymeric shell can be determined using the procedure described in the section on Test this report.
[00109] The particles of the first metal are preferably adsorbed on the polymeric shell by: (i) adsorption of nanoparticles stabilized by loading the first metal on the polymeric shell; (ii) adsorption of sterically stabilized nanoparticles of the first metal onto the polymeric shell; or (iii) adsorption of particles of the first metal that are formed by reduction in situ. These methods are described in more detail below. Deposition of the first metal: adsorption of charge-stabilized nanoparticles
[00110] In some examples, the particles of the first metal are charge-stabilized nanoparticles that are adsorbed on the polymeric shell. Charged stabilized nanoparticles are nanoparticles that include a charged species adsorbed on its surface. Since the stabilizer is a charged species, it will impart a charged surface to the nanoparticles that will be exploited in the adsorption of metallic particles to the surface of the polymeric shell. In some instances, particles of the first metal are adsorbed to the polymeric shell by electrostatic interaction.
[00111] The particles are preferably adsorbed on a surface modifying agent that is part of the polymeric envelope. The surface modifying agent can be adsorbed and / or absorbed in the polymeric shell. Preferably, the polymeric shell was obtained by an emulsification process in which the surface modifying agent was employed as an emulsifier, the emulsifier being retained in the resulting shell. The surface modifying agent preferably has a charged surface that is used to electrostatically attract and adsorb the charge-stabilized nanoparticles into the polymeric shell. In some instances, the particles of the first metal are stabilized with charge by an anionic stabilizer. In some instances, the anionic stabilizer is selected from boron hydride and citrate anions. In some examples, the anionic stabilizer is an anionic surfactant, for example, an anionic surfactant selected from sodium dodecyl sulfate, sodium lauryl ether (laureth) sulfate, benzene sulfonate dodecyl, perfluorooctane sulfonate, dioctyl sulfosuccinate and sodium and sodium stearate. Preferably, the particles are nanoparticles stabilized with borohydride or stabilized with citrate.
[00112] In some examples, the particles of the first metal have a zeta potential of -20 mV to -150 mV, for example, from -30 mV to -90 mV.
[00113] Where the particles of the first metal are stabilized by an anionic stabilizer, it is preferable that the surface of the polymeric envelope is neutral or cationic. In some examples, the polymeric shell has a substantially neutral surface with a zeta potential of -10 mV to +10 mV, for example, from -5 mV to +5 mV. In some examples, the polymeric shell has a positively charged surface, for example, having a zeta potential of +20 mV to +150 mV, for example, from +30 mV to +90 mV.
[00114] In some examples, the particles of the first metal are stabilized by an anionic stabilizer and the polymeric shell includes a non-ionic surface modifying agent. In some examples, the surface modifying agent is a nonionic polymer, for example, a nonionic polymer selected from poly (vinyl alcohol) and poly (vinylpyrrolidone).
[00115] In some examples, the particles of the first metal are stabilized by an anionic stabilizer and the polymeric shell includes a cationic surface modifying agent. The surface modifying agent can be a cationic surfactant or a cationic polymer. Examples of cationic surfactants include, but are not limited to, alkylammonium surfactants, such as cetyl trimethylammonium bromide, dodecyl dimethylammonium bromide, cetyl trimethylammonium chloride, benzalkonium chloride, cetylpyridinium chloride, dioctadyl dimethyl dimethylamine and bichloride. Examples of cationic polymers include, without limitation, poly (diethylaminoethyl methacrylate), poly (dimethylaminoethyl methacrylate), poly (t-butylaminoethyl methacrylate) and diblock copolymers formed by a first block composed of a poly (acrylate of acrylate) aminoalkyl) and a second block composed of a poly (alkyl acrylate). Most preferably, the surface modifying agent is cetyl trimethylammonium bromide.
[00116] Alternatively, the particles of the first metal can be stabilized by charge by a cationic stabilizer. Examples of cationic stabilizers include cationic surfactants such as quaternary ammonium surfactants, for example, cetyl trimethylammonium bromide, tetraoctylamonium bromide and dodecyl trimethylammonium bromide. Other quaternary ammonium surfactants include esterquats, that is, quaternary ammonium surfactants containing an ester group. In some examples, the particles of the first metal have a zeta potential of +20 mV to +150 mV, for example, from +30 mV to +90 mV.
[00117] When the particles of the first metal are stabilized by a cationic stabilizer, it is preferable that the surface of the polymeric envelope is neutral or anionic. In some examples, the polymeric shell has a substantially neutral surface with a zeta potential of -10 mV to +10 mV, for example, from -5 mV to +5 mV. In some examples, the polymeric shell has a positively charged surface, for example, having a zeta potential of -20 mV to -150 mV, for example, -30 mV to -90 mV.
[00118] In some examples, the particles of the first metal are stabilized by a cationic stabilizer and the polymeric shell includes a non-ionic surface modifying agent. In some examples, the surface modifying agent is a nonionic polymer, for example, a nonionic polymer selected from poly (vinyl alcohol) and poly (vinylpyrrolidone).
[00119] In some examples, the particles of the first metal are stabilized by a cationic stabilizer and the polymeric shell includes an anionic surface modifying agent. The surface modifying agent can be an anionic surfactant or an anionic polymer. Examples of anionic surfactants include, without limitation, sodium dodecyl sulfate, sodium lauryl ether sulfate, dodecyl benzene sulfonic acid, sodium dioctyl sulfosuccinate, perfluorooctane sulfonate, sodium dioctyl sulfosuccinate and sodium stearate. Examples of anionic polymers include, without limitation, polyacids, such as poly (acrylic acid) and poly (methacrylic acid).
[00120] The particles of the first metal can, alternatively, be stabilized with charge by a zwitterionic stabilizer. In some instances, the zwitterionic stabilizer is a zwitterionic surfactant. Examples of zwitterionic surfactants include aminobetaines, imidazoline derivatives and phospholipids, for example, phosphatidylcholines.
Charge-stabilized nanoparticles can be prepared using suitable procedures known in the art (see, for example, G. Frens, Nature, 1973, 241,20-22). Such procedures will normally involve the reduction of metal ions in solution in the presence of a charged stabilizer. Thus, charge-stabilized nanoparticles can be obtained by providing a solution containing ions of the first metal and a charged stabilizer and reducing the ions to form metallic particles that are stabilized with charge by the stabilizer.
[00122] In some examples, metal ions in solution are reduced by a reducing agent that becomes the stabilizer charged, for example, by sodium borohydride or sodium citrate. By way of illustration and without limitation, gold nanoparticles stabilized with borohydride can be prepared by contacting an aqueous solution of chlorouric acid with sodium borohydride.
The resulting charge-stabilized nanoparticles can then be brought into contact with uncoated microcapsules under appropriate conditions, for example, at room temperature. The microcapsules can then be washed to remove any unbound particles.
[00124] Preferably, the ions of the first metal are present in the solution at a concentration of 0.005 to 50 mM, for example, 0.01 to 20 mM, for example, 0.05 to 5 mM. Preferably, the loaded stabilizer is present in the solution at a concentration of 0.005 to 50 mM, for example, 0.01 to 20 mM, for example, 0.05 to 5 mM. Deposition of the first metal: adsorption of aesthetically stabilized nanoparticles
[00125] In some examples, the first metal is deposited by the adsorption of sterically stabilized nanoparticles of the first metal on the surface of the polymeric shell. The sterically stabilized nanoparticles are generally made up of a polymer or other macromolecule that is adsorbed on the surface of the metallic particles, forming a protective shield around the particles and minimizing the aggregation. The size of the steric stabilizer can be explored to adsorb the metallic particles on the surface of the polymeric investment. In some examples, particles of the first metal are adsorbed to the polymeric shell by steric interaction.
[00126] In some examples, nanoparticles are sterically stabilized by a polymeric stabilizer.
[00127] Preferably, the polymer includes one or more groups selected from carboxyl, hydroxyl, amine and ester groups. The polymer can be a homopolymer or a copolymer (for example, a graft cup-polymer or a block copolymer). Examples of suitable polymers include poly (ethylene oxide), polyethylene glycol, poly (acrylic acid), poly (acrylamide), poly (ethylene imine), poly (vinyl alcohol), carboxymethylcellulose, chitosan, guar gum, gelatin, amylose, amylopectin, and sodium alginate.
[00128] Preferably, the polymeric stabilizer has an average molecular weight of at least 5 kDa, more preferably at least 10 kDa, more preferably at least 20 kDa. Preferably, the molecular weight of the polymeric stabilizer is 5 to 100 kDa, more preferably 10 to 80 kDa, more preferably 20 to 40 kDa.
[00129] In some examples, the polymeric stabilizer is a nonionic polymer. Examples of nonionic polymers include, without limitation, poly (vinyl alcohol), poly (vinyl propylene), poly (ethylene glycol) and poly (vinylpyrrolidone). Poly (vinylpyrrolidone) is particularly preferred as a steric stabilizer.
[00130] In some examples, the polymeric stabilizer is a cationic polymer. Examples of cationic polymers include, without limitation, polymers of poly (allylamine), for example poly (allylamine hydrochloride).
[00131] In some examples, the polymeric stabilizer is an anionic polymer. Examples of anionic polymers include, without limitation, polyacids, for example, poly (acrylic acid) or poly (methacrylic acid).
[00132] In some examples, the nanoparticles are sterically stabilized by a polymeric surfactant. Examples of suitable surfactants include, without limitation, polyoxyalkylene glycol alkyl ethers (eg polyoxyethylene glycol alkyl ethers and polyoxypropylene glycol alkyl ethers), sorbitan esters (eg polysorbates), fatty acid esters, poly (isobutenyl anhydride) derivatives ) succinic and amine oxides.
[00133] As in the polymeric stabilizer, the polymeric surfactant preferably has an average molecular weight of at least 5 kDa, more preferably at least 10 kDa, more preferably at least 20 kDa. Preferably, the polymeric surfactant has an average molecular weight of 5 to 100 kDa, more preferably 10 to 80 kDa, more preferably 20 to 40 kDa.
[00134] The particles are preferably adsorbed on a surface modifying agent that is part of the polymeric envelope. The surface modifying agent can be adsorbed and / or absorbed in the polymeric shell. Preferably, the polymeric shell was obtained by an emulsification process in which the surface modifying agent was used as an emulsifier, the emulsifier being retained in the resulting shell. The sterically stabilized nanoparticles preferably bind via steric interactions to the surface modifying agent.
[00135] In some examples, the surface modifying agent is a nonionic surface modifying agent, for example, a nonionic surfactant or a nonionic polymer. Examples of non-ionic polymers include, without limitation, poly (vinyl alcohol) and poly (vinylpyrrolidone). Most preferably, the non-ionic polymer is poly (vinyl alcohol).
[00136] In some examples, the surface modifying agent is a cationic surface modifying agent, for example, a cationic surfactant or a cationic polymer. Examples of cationic surfactants include, without limitation, cetyl trimethylammonium bromide, dodecyl dimethylammonium bromide, cetyl trimethylammonium chloride, benzalkonium chloride, cetylpyridinium chloride, dioctadecyl dimethylammonium chloride and dioctamyl dimethyl bromide. Preferably, the cationic surface modifying agent is cetyl trimethylammonium bromide.
[00137] In some examples, the surface modifying agent is an anionic surface modifying agent, for example, an anionic surfactant or an anionic polymer. Examples of anionic surfactants include, without limitation, sodium dodecyl sulfate, sodium lauryl ether (laureth) sulfate, dodecyl benzene sulfonic acid, sodium dioctyl sulfosuccinate, perfluorooctanesulfonate, sodium dioctyl sulfosuccinate and sodium stearate. Examples of anionic polymers include, without limitation, polyacids such as poly (acrylic acid) and poly (methacrylic acid).
[00138] Suitable procedures for preparing sterically stabilized nanoparticles are known in the art (see, for example, Horiuchi et al, Surface and Coatings Technology, 2010, 204, 3811-3817). By way of illustration, sterically stabilized nanoparticles can be prepared by reducing the metal ions in solution in the presence of a stabilizer.
[00139] Thus, in some examples, sterically stabilized nanoparticles are obtained by providing a solution containing ions of the first metal and a stabilizer, and reducing the ions to form metallic particles that are sterically stabilized by the stabilizer. Preferably, the ions of the first metal are present in the solution at a concentration of 0.01 to 100 mM, for example 0.05 to 50 mM, for example 0.1 to 10 mM. Preferably, the stabilizer is present in the solution at a concentration of 0.0001 to 1 mM, for example, from 0.005 to 0.5 mM, for example, from 0.001 to 0.1 mM.
[00140] The particles of the first metal can be adsorbed onto the polymeric shell of the microcapsule by putting the microcapsule in contact with a slurry containing the said particles. Preferably, the metallic nanoparticles are present in the slurry in an amount greater than 0.2% by weight and the suspension contains less than 0.01% by weight of unbound stabilizer.
[00141] Contact may occur under environmental conditions. However, to facilitate the adsorption of particles on the surface of the microcapsule, the microcapsules can be heated in order to increase the penetration of the sterically stabilized particles into the polymeric shell. Preferably, the microcapsules are heated to a temperature of 30 ° C to 80 ° C, for example, 40 ° C to 70 ° C. In some examples, the polymeric shell includes an amorphous polymer and the microcapsule is heated to a temperature above the standard ambient temperature, but below the glass transition temperature (Tg) of the polymer. Preferably, the elevated temperature is not more than 30 ° C below, for example, no more than 20 ° C below, the glass transition temperature of the amorphous polymer. Examples of amorphous polymers include, without limitation, polyacrylates, for example, poly (methyl methacrylate) and poly (ethyl methacrylate). The glass transition temperature of the polymer can be determined by differential scanning calorimetry (DSC) following ASTM E1356 (("Standard Test Method for Assignment of the Glass Transition Temperature by Differential Scanning Calorimetry") Vitreous by Differential Scanning Calorimetry)).
[00142] The polymer glass transition temperature can be determined by differential scanning calorimetry (DSC) following ASTM E1356 ("Standard Test Method for Glass Transition Temperature Assignment by Differential Scanning Calorimetry"). Deposition of the first metal: deposition by reduction in situ
[00143] In some examples, the particles of the first metal are adsorbed onto the polymeric shell by putting the uncoated microcapsule in contact with a solution containing ions of the first metal and a reducing agent. The presence of the reducing agent causes the ions of the first metal to be reduced in situ. As metal ions are reduced, they precipitate from the solution as metallic particles and seek to reduce the energy of the system by adsorbing to the polymeric shell of the microcapsule. The first metal can also be adsorbed to the polymeric shell of the microcapsule during the deposition process in the form of ions that have not been reduced by the reducing agent.
[00144] The reducing agent that is put in contact with the uncoated microcapsule is preferably in solution. More preferably, the reducing agent is added to a solution containing the metal ions and the uncoated microcapsule. Thus, the deposition of metallic particles on the surface of the microcapsules can be achieved by preparing an aqueous solution containing ions of the first metal and uncoated microcapsules. A reducing agent is then added to the solution, resulting in the reduction of metal ions and the precipitation of particles of the first metal on the surface of the microcapsules. The reaction can progress for a time sufficient to allow the desired deposition of the metal particles on the surface of the microcapsule. The capsules can then be washed, separated from the other reagents and redispersed in water. The deposition process can be carried out at room temperature.
[00145] Preferably, the ions of the first metal are present in the solution at a concentration of 0.005 to 50 mM, for example, 0.01 to 20 mM, for example, 0.05 to 5 mM. Preferably, the reducing agent is present in the solution at a concentration of 0.05 to 500 mM, for example, 0.1 to 200 mM, for example, 0.5 to 50 mM.
[00146] The particles are preferably adsorbed on a surface modifying agent that is present in the polymeric shell. The surface modifying agent can be adsorbed and / or absorbed in the polymeric shell. Preferably, the polymeric shell was obtained by an emulsification process in which the surface-modifying agent was employed as an emulsifier, the emulsifier being retained in the resulting shell. The particles of the first metal can be adsorbed on the polymeric shell by one or more selected interactions between aesthetic and electrostatic interactions.
[00147] In some examples, the surface modifying agent is a nonionic surface modifying agent, for example, a nonionic polymer. Examples of nonionic polymers include, without limitation, poly (vinyl alcohol) and poly (vinylpyrrolidone). Most preferably, the non-ionic polymer is poly (vinyl alcohol).
[00148] In some examples, the surface modifying agent is a cationic surface modifying agent, for example, a cationic surfactant or a cationic polymer. Examples of cationic surfactants include, without limitation, cetyl trimethylammonium bromide, dodecyl dimethylammonium bromide, cetyl trimethylammonium chloride, benzalkonium chloride, cetylpyridinium chloride, dioctadecyl dimethylammonium chloride and dioctamyl dimethyl bromide. Preferably, the surface modifying agent is cetyl trimethylammonium bromide.
[00149] In some examples, the surface modifying agent is an anionic surface modifying agent, for example, an anionic surfactant or an anionic polymer. Examples of anionic surfactants include, without limitation, sodium dodecyl sulfate, sodium lauryl ether (laureth) sulfate, dodecyl benzene sulfonic acid, sodium dioctyl sulfosuccinate, perfluorooctanesulfonate, sodium diostyl sulfosuccinate and sodium stearate. Examples of anionic polymers include, without limitation, polyacids such as poly (acrylic acid) and poly (methacrylic acid). Deposition of the second metal
[00150] Once the particles of the first metal have been adsorbed on the polymeric shell, a film of a second metal is formed on the particles of the first metal, thus covering the polymeric shell with a continuous metallic film that surrounds the microcapsule. Preferably, the thickness of the metallic coating is substantially uniform throughout the coating.
[00151] The metallic film is preferably formed by an autocatalytic coating process (electroless) in which the deposition of the second metal is catalyzed by the adsorbed particles of the first metal. The process of chemical deposition (electroless) will comprise placing the microcapsules on which the particles of the first metal have been deposited in contact with an ion solution of the second metal in the presence of a reducing agent, in the absence of an electric current. The reducing agent is typically a mild reducing agent, such as formaldehyde, and the autocatalytic coating is preferably carried out under alkaline conditions. Once the electroplating reaction begins, the deposition of the metallic coating can become autocatalytic. The thickness of the metallic film can be controlled by limiting the concentration of the ions of the second metal in solution and / or the duration of the autocatalytic coating process (electroless).
[00152] Appropriate techniques for carrying out the autocatalytic coating process (electroless) are described, for example, in the following documents: Basarir et al., ACS Applied Materials & Interfa-ces, 2012, 4 (3), 1324- 1329; Blake et al., Langmuir, 2010, 26 (3), 1533-1538; Chen et al. Journal of Physical Chemistry C, 2008, 112 (24), 8870-8874; Fujiwara et al. Journal of the Electrochemical Society, 2010, 157 (4), pp.D211-D216; Guo et al., Journal of Applied Polymer Science, 2013, 127 (5), 4186-4193; Haag et al. Surface and Coatings Technology, 2006, 201 (6), 2166-2173; Horiuchi et al. , Surface & Coatings Technology, 2010, 204 (23), 3811-3817; Ko et al. Journal of the Electrochemical Society, 2010, 157 (1), pp.D46- D49; Lin et al. , International Journal of Hydrogen Energy, 2010, 35 (14), 7555-7562; Liu et al., Langmuir, 2005, 21 (5), 1683-1686; Ma et al., Applied Surface Science, 2012, 258 (19), 7774-7780; Miyoshi et al., Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008, 321 (1-3), 238-243; Moon et al., 2008, Ultramicroscopy (Ultramicroscopy), 108 (10), 1307-1310; Wu et al. , Journal of Colloid and In-terface Science, 2009, 330 (2), 359-366; Ye et al., Materials Letters, 2008, 62 (4-5), 666-669; and Zhu et al., Surface and Coatings Technology, 2011,205 (8-9), 2985-2988.
[00153] By way of illustration and without limitation, a silver film can be prepared by forming a dispersion containing silver nitrate, formaldehyde, ammonia and microcapsules containing particles of the first metal. The dispersion is then stirred for a period of time sufficient to obtain a metallic film of the desired thickness. The capsules can then be washed, for example, by centrifugation, to separate them from the coating solution.
The ions of the second metal are preferably present in the solution at a concentration of 0.05 to 2000 mM, for example, from 0.1 to 1750 mM, for example, from 0.5 to 1500 mM. Preferably, the reducing agent is present in the solution at a concentration of 0.05 to 3500 mM, for example, 0.1 to 3000 mM, for example, 0.5 to 2500 mM. Preferably, the second metal and the reducing agent are present in the solution in a molar ratio of second metal to reducing agent from 1:10 to 4: 1, for example, from 1: 5 to 2: 1, for example, from 1: 3 to 1: 1.
[00155] The autocatalytic coating process (electroless) can be carried out at any suitable temperature, for example, a temperature from 0 to 80 ° C. Preferably, the autocatalytic (electroless) coating process is carried out at room temperature. Characteristics and properties of coated microcapsules
[00156] The coated microcapsules can be obtained in a variety of different particle sizes. Preferably, the coated microcapsules have a particle size of at least 0.1 microns, more preferably at least 1 micron. Typically, the coated microcapsules will have a particle size of 500 microns or less, such as 100 microns or less, and more preferably 50 microns or less. Preferably, the coated microcapsules have a particle size of 0.1 to 500 microns, for example, 1 to 100 microns, for example, 1 to 30 microns, for example, 1 to 20 microns. The particle size of coated and uncoated microcapsules can be determined using the test procedure described in the Test Methods section of this report.
[00157] The coated microcapsules include a metallic coating with a maximum thickness of 1000 nm. The thickness of the metallic coating can be chosen so that the coated microcapsules break and release the encapsulated liquid core material under particular conditions, for example, under particular stresses. For example, when coated microcapsules include a perfume oil and are part of a fragrance formulation that is used by a user, the metallic coating may break during use, for example, due to the friction of the skin to which the formulation has been applied. applied. In this way, perfume oil can be released in a controlled manner so that it is noticeable to the user for a long period of time.
[00158] On the other hand, it is also desirable that the metallic coating has a minimum thickness in order to reduce the likelihood of solvents permeating through the microcapsule wall and / or that the metallic coating breaks prematurely when the coated microcapsules are stored , transported or used. This is particularly important in the case of fine fragrance formulations, which will typically include a polar solvent such as ethanol in which the microcapsules are dispersed.
[00159] In some examples, the metallic coating has a maximum thickness of 500 nm, for example, a maximum thickness of 400 nm, for example, a maximum thickness of 300 nm, for example, a maximum thickness of 200 nm, for example, a maximum thickness of 150 nm, for example, a maximum thickness of 100 nm, for example, a maximum thickness of 50 nm. In some examples, the metallic coating has a minimum thickness of 1 nm, for example, a minimum thickness of 10 nm, for example, a minimum thickness of 30 nm. In some examples, the metallic coating has: a minimum thickness of 1 nm and a maximum thickness of 500 nm; a minimum thickness of 10 nm and a maximum thickness of 300 nm; or a minimum thickness of 10 nm and a maximum thickness of 200 nm. Preferably, the metallic coating has: a minimum thickness of 10 nm and a maximum thickness of 150 nm; a minimum thickness of 10 nm and a maximum thickness of 100 nm; a minimum thickness of 20 nm and a maximum thickness of 100 nm.
[00160] The coated microcapsules are designed to release their liquid core material when the microcapsules are broken. The rupture can be caused by forces applied to the enclosure during mechanical interactions. Microcapsules can have a fracture strength of about 0.1 MPa to about 25 MPa. The microcapsules preferably have a fracture resistance of at least 0.5 MPa. In order for the microcapsules to be readily friable, they preferably have a fracture strength of less than 25 MPa, more preferably less than 20 MPa, more preferably less than 15 MPa. For example, microcapsules can have a fracture resistance of 0.5 to 10 MPa. The fracture resistance of the microcapsules can be measured according to the Fracture Resistance Test Method described in WO 2014/047496 (see pages 28-30 of the same).
[00161] The coated microcapsules can be characterized in terms of their permeability. A coated microcapsule can retain more than 50% by weight of the liquid core material in the Ethanol Stability Test described herein. More preferably, the coated microcapsule retains more than 70% by weight of the liquid core material, for example, more than 80% by weight, for example, more than 85% by weight, for example, more than 90% by weight, by example, more than 95% by weight, for example, more than 98% by weight, when tested in the Ethanol Stability Loss Test (Ethanol Stability Leakage Test) described herein.
[00162] In some instances, the metallic coating is applied to an uncoated microcapsule that would otherwise retain less than 20% by weight of its liquid core material when tested in the Ethanol Stability Leakage Test Test) described herein, for example, less than 10%, for example, less than 5%, for example, less than 1%. Formulations and Uses
[00163] The coated microcapsules will typically be formulated as a plurality of coated microcapsules. Thus, formulations may contain several of the coated microcapsules disclosed herein. The coated microcapsules will typically be dispersed in a solvent. For example, coated microcapsules can be dispersed in water or in a polar solvent, for example, an alcohol such as ethanol.
[00164] Preferably, the formulation includes coated microcapsules in an amount of at least 1% by weight of the formulation. For example, the coated microcapsules can be present in an amount of at least 5% by weight, at least 7% by weight or at least 10% by weight of the formulation. The formulation can include a mixture of different coated microcapsules of the present disclosure, the mixture containing a plurality of coated microcapsules containing a first liquid core material and a plurality of coated microcapsules containing a second liquid core material. Alternatively or in addition, the formulation may contain other microcapsules, for example, uncoated microcapsules, in addition to the coated microcapsules described herein.
[00165] Preferably, at least 75%, 85% or up to 90% by weight of the coated microcapsules in the formulation have a particle size of 1 micron to 100 microns, more preferably 1 micron to 50 microns, even more preferably 10 microns to 50 microns, most preferably 1 micron to 30 microns. Preferably, at least 75%, 85% or up to 90% by weight of the coated microcapsules have a polymeric shell thickness from 60 nm to 250 nm, more preferably from 80 nm to 180 nm, even more preferably from 100 nm to 160 nm .
[00166] The coated microcapsules can be used in a wide variety of consumer products. Thus, coated microcapsules can be used in products for baby care, beauty care, tissue care, home care, family care, female care or health care.
[00167] Preferably, coated microcapsules are used in topically applied products, including fine fragrances and skin care products, including shaving products. The coated microcapsules described here can be used in consumer products (that is, products intended to be sold to consumers without further modification or processing). Non-limiting examples of consumer products useful in this context include hair care products (human, dog and / or cat), including bleaching, coloring, dyeing, conditioning, growth, removal, growth retardation, washing (shampoo), hairstyles (styling); deodorants and antiperspirants; personal cleaning; color cosmetics; products and / or methods related to the treatment of skin (human, dog and / or cat), including application of creams, lotions and other products applied topically for consumer use; and products and / or methods related to materials administered orally to improve the appearance of hair, skin and / or nails (from humans, dogs and / or cats); shaving products; body sprays; and fine fragrances such as colognes and perfumes; products for treating fabrics, hard surfaces and any other surfaces in the fabric and housewares area, including: air care, car care, dishwashing, fabric conditioning (including fabric softening), laundry detergents, additives and / or care for washing and rinsing clothes, cleaning and / or treating hard surfaces and other cleaning products for consumer or institutional use; products related to absorbent and / or non-absorbent disposable items, including adult incontinence garments, bibs, diapers, training pants, baby wipes for babies and young children; hand soaps, shampoos, lotions, oral care implements and clothes; products such as dry or wet paper towels, facial paper towels, disposable tissues, towels and or disposable cleaning cloths; products related to menstrual pads, incontinence pads, interlabial pads, panties protectors, pessaries, sanitary pads, tampons and tampon applicators and / or cleaning wipes.
[00168] In particular, a fragrance formulation containing a plurality of coated microcapsules as disclosed, the coated microcapsules containing a liquid core material that includes a perfume oil. The formulation may contain a polar solvent in which the coated microcapsules are dispersed. In some examples, the polar solvent is ethanol. In some examples, the fragrance formulation includes a plurality of coated microcapsules as described herein, dispersed in ethanol. In some instances, the fragrance formulation is a fine fragrance formulation. Test Methods Test method for measuring the size of microcapsules
[00169] The dimensions of uncoated and coated microcapsules can be measured using a Malvern Mastersizer Hydro 2000SM particle size analyzer. Measurements are performed according to the British standard (British Standard - BS ISO 13099-1: 2012 ("Colloidal systems - Methods for determining the zeta potential"). Test method for measuring the size of metallic particles
[00170] The dimensions of metallic particles can be determined by dynamic scattering of light. Specifically, a transmission electron microscope with field-emission gun (FEGTEM) Malvern Nano-ZS Zetasizer and FEI Tecna TF20 equipped with HAADF detector and CCD Gatan Orius SC600A camera can be used. Test method to measure the thickness of the polymeric shell and the metallic coating
[00171] The thickness of the polymeric casing and the metallic coating can be measured using microscopic sections with microtome (microtoming) and FEGTEM. To prepare cross-sectional samples of the capsule for TEM imaging, 1% of the washed capsules are centrifuged and redispersed in 1 ml of ethanol. The capsule samples are then air dried and mixed with EPO FIX epoxy resin. The sample is allowed to harden overnight and the 100 nm thick microtome samples are floated on water and fitted to TEM grids. FEGTEM is used to generate microtome images and the thickness of the polymeric shell and metallic coating can be determined using a computer program, such as Image J. Test method to measure the adsorption density of metal particles on the surface of the capsule
[00172] Densities of surface adsorption of metallic particles can be measured directly from TEM images. Adsorption densities can be measured for small sample compartments on the surface of the capsule. The distance from the center of the sphere is then observed in each case * Each measurement was then corrected for both surface curvatures and halved to compensate for the transparent nature of the capsules (the TEM image shows the metal particles on both sides of the capsule ). The size distribution of the capsules is then used to convert the numerical density obtained from these images into a 2D surface coverage (percentage). Test method for measuring zeta potentials of uncoated microcapsules, metallic particles and coated microcapsules
[00173] The zeta potentials of uncoated microcapsules, metallic particles and coated capsules can be analyzed using a Zetasizer Malvern nano-ZS. The Zeta potentials are measured according to the British standard BS ISO 13099-1: 2012 ("Colloidal systems - Methods for determining the zeta potential").
[00174] Test method for analyzing the chemical composition of coated microcapsules
[00175] The chemical composition of the coated microcapsules can be analyzed using a dispersive energy X-ray spectroscope (EDX) Oxford Instruments INC A 350 with 80 mm SDD X-Max detector, which is installed in FEGTEM; and EDX at FEGTSEM. Ethanol Stability Test
[00176] The Ethanol Stability Test refers to the following test procedure.
[00177] A known volume of microcapsules (coated or uncoated microcapsules) is isolated and dispersed in an aqueous solution consisting of 1 part of water to 4 parts of absolute ethanol. The dispersion is heated to 40 ° C. After 7 days at 40 ° C, the microcapsules are isolated from the aqueous solution using centrifugation at 7000 rpm for 1 minute.
[00178] The aqueous solution is then subjected to analysis using gas chromatography to determine the material content of the liquid core that has leaked out of the microcapsules. Samples are evaluated using a fused silica column 3 m long and 0.25 mm internal diameter, coated with a 0.25 mm film of 100% dimethyl polysiloxane stationary phase. The column temperature is programmed to increase from 50 ° C to 300 ° C at a rate of 20 ° C per minute. A Clarus 580 gas chromatograph is used for the analysis.
[00179] When the loss of the liquid core material of the coated microcapsules is compared to that of the uncoated microcapsules, the uncoated microcapsules can be subjected to the washing steps of the coating procedure, to ensure that there is an equivalent loss of liquid core material in coated and uncoated microcapsules prior to the Ethanol Stability Test.
[00180] To confirm the presence of the liquid core material within the coated microcapsules, a known sample of capsules is crushed between two glass slides and washed and collected in a flask with 5 ml of ethanol. The capsules are isolated from the aqueous solution using centrifugation at 7000 rpm for 1 minute. The aqueous solution is then subjected to analysis using gas chromatography to determine the content of the liquid core material that has leaked out of the microcapsules.
[00181] The following examples describe and illustrate modalities within the scope of the present invention. The Examples are provided for illustrative purposes only and should not be construed as limitations of the present invention, since many variations are possible, without departing from the spirit and scope of the invention.
[00182] Unless otherwise specified, the test procedures used in these Examples are those specified in the Test Methods section of this report. Example 1: Synthesis of microcapsules containing a polyacrylate shell and an n-hexadecane core
[00183] The following procedure was used to prepare micro-capsules containing a polyacrylate shell and a n-hexadecane core. Microcapsules were prepared by a coacervation procedure that involved oil-in-water emulsification followed by solvent extraction. Poly (vinyl alcohol) was used as an emulsifier.
[00184] 2.5 g of poly (methyl methacrylate) (PMMA, 99%, Sigma) were dissolved in 70.5 g of dichloromethane (DCM) (> 99%, Acros Organics). 5.0 g of n-hexadecane (99%, Acros Organics) were added to this solution and mixed to form a single phase ("core" phase). In a 100 ml volumetric flask, a 2% emulsifier solution was prepared by dissolving a sufficient amount of poly (vinyl alcohol) (PVA, 67 kDa, 8-88 Fluka) in Milli-Q water, to form the " to be continued". 7 ml of the "core" and "continuous" phase were added to a glass vial and emulsified using a homogenizer (IKA T25 Ultra-Turrax) at 15000 rpm for 2 min. The stabilized emulsion was then magnetically stirred at 400 rpm while 86 ml of the "continuous" phase was poured slowly. The diluted emulsion was then stirred at 400 rpm for 24 hours at room temperature to allow the capsule to form. The dispersion was transferred to a separatory funnel and the capsules left to become cream. The aqueous phase of the excess PVA was removed and replaced with Milli-Q water three times. The capsules were redispersed in 50 ml of Milli-Q water. Example 2: Synthesis of microcapsules containing a polyacrylate shell and a toluene core
[00185] The following procedure was used to prepare micro-capsules containing a polyacrylate shell and a toluene core. Microcapsules were prepared by a coacervation procedure that involved oil-in-water emulsification followed by solvent extraction. Cetyl trimethyl ammonium bromide as an emulsifier.
[00186] 5 g of poly (ethyl methacrylate) (PEMA, 99%, Sigma) were dissolved in 81 g of dichloromethane (DCM) (> 99%, Acros Organics). 14 g of toluene (99%, Acros Organics) was added to this solution and mixed to form a single phase ("core" phase). In a 100 ml volumetric flask, a 0.28% emulsifier solution was prepared by dissolving a sufficient amount of cetyl trimethylammonium bromide (CTAB, 98%, Sigma) in Milli-Q water, to form the "continuous" phase . 7 ml of the "core" and "continuous" phase were added to a glass vial and emulsified using a homogenizer (IKA T25 Ultra-Turrax) at 15000 rpm for 2 min. The stabilized emulsion was then magnetically stirred at 400 rpm while 86 ml of the "continuous" phase was poured slowly. The diluted emulsion was then stirred at 400 rpm for 24 hours at room temperature to allow the capsule to form. The capsules were isolated by washing by centrifugation (Heraeus Megafuge R16) and removal of the supernatant three times at 4000 rpm for 5 min. The capsules were redispersed in 25 ml of Milli-Q water. Example 3: Synthesis of microcapsules containing a polyacrylate shell and a hexyl salicylate core
[00187] The following procedure was used to prepare micro-capsules containing a polyacrylate shell and a hexyl salicylate core. Microcapsules were prepared by a coacervation procedure that involved oil-in-water emulsification followed by solvent extraction. Poly (vinyl alcohol) was used as an emulsifier.
[00188] 10 g of poly (methyl methacrylate) (PMMA, 99%, Sigma) were dissolved in 60 g of dichloromethane (DCM) (> 99%, Acros Or-ganics). 30 g of hexyl salicylate (Procter and Gamble) was added to this solution and mixed until it formed a single phase ("core" phase). In a 100 ml volumetric flask, a 0.28% emulsifier solution was prepared by dissolving a sufficient amount of cetyl trimethylammonium bromide (CTAB, 98%, Sigma) in Mill-Q water, to form the "continuous" phase . 7 ml of the "core" and "continuous" phase were added to a glass vial and emulsified using a homogenizer (IKA T25 Ultra-Turrax) at 15000 rpm for 2 min. The stabilized emulsion was then magnetically stirred at 400 rpm while 86 ml of the "continuous" phase was poured slowly. The diluted emulsion was then stirred at 400 rpm for 24 hours at room temperature to allow the capsule to form. The capsules were isolated by washing by centrifugation (Heraeus Megafuge R16) and removal of the supernatant three times at 4000 rpm for 5 min. The capsules were redispersed in 50 ml of Milli-Q water. Example 4: Preparation of gold stabilized nanoparticles with charge
[00189] The following procedure was used to prepare gold nanoparticles stabilized with borohydride.
[00190] 0.34 g of HAuCl4 was dissolved in Milli-Q water in a 25 ml volumetric flask. 0.036 g of HCl were dissolved in Milli-Q water in a 25 ml volumetric flask. The HAuCl4 and HCl solutions were combined in a separate flask. 1.25 ml of this solution was added dropwise to 47.25 ml of Milli-Q water and stirred vigorously. A borohydride solution was prepared by adding 0.095 g of NaBH4 dissolved in 25 ml of Milli-Q water, to 0.1 g of NaOH dissolved in 25 ml of Milli-Q water. 1.5 ml of this solution was added in one go, and the solution was stirred for 1 minute. The solution changed color from pale yellow to dark ruby red, indicating the formation of Au nanoparticles. Example 5: Adsorption of gold nanoparticles stabilized with charge in microcapsules
[00191] The following procedure was used to adsorb the charge-stabilized gold na-noparticles of Example 4 onto the surface of the microcapsules of Examples 2 and 3.
[00192] 6 ml of the Au nanoparticles were added to a baby and shaken vigorously. 0.5 ml of microcapsules were added dropwise and the mixture stirred vigorously for another 10 minutes. The microcapsules were collected by centrifugation (Heraeus Megafuge R16) and removal of the supernatant four times at 4000 rpm for 10 min, to remove excess nanoparticles, and were then redispersed in water (2 ml). Example 6: Preparation of sterically stabilized platinum nanoparticles
[00193] The following procedure was used to prepare platinum nano-particles stabilized with poly (vinyl pyrrolidone).
[00194] 0.5 g of poly (vinylpyrrolidone) (PVP, 40 kDa, Fluka) were dissolved in 250 ml of Milli-Q water. 31.25 ml of this solution was added to a 1 L volumetric flask and the flask filled to 1 L with Milli-Q water to obtain a 0.00625 wt% PVP solution. 100 ml of this PVP solution was added in a 250 ml conical flask, then 0.23 g of H2PtCl6-6H2O was added and stirred to dissolve. A 0.5 mM NaBH4 solution was prepared by dissolving 0.189 g of NaBH4 in 10 ml of Milli-Q water. 0.4 ml of this solution was added to the platinum-PVP salt solution with vigorous stirring for 2 minutes. The solution immediately turned dark brown and was left to stand overnight to form Pt-PVP nanoparticles. Example 7: Adsorption of sterilized platinum nanoparticles in microcapsules
[00195] The following procedure was used to adsorb the PVP-stabilized platinum na-particles of Example 6 onto the surface of the microcapsules of Examples 1-3.
[00196] 2 ml of capsules were added to 5 ml of platinum nanoparticles stabilized with PVP in a 40 ml glass vial and mixed in a carousel mixer ("carousel ') for 10 min. The capsules were then washed by centrifugation. at 4000 rpm for 5 minutes, three times The capsules were redispersed in 30 ml of Milli-Q water Example 8: Adsorption of platinum nanoparticles in microcapsules via in situ reduction.
[00197] The following procedure was used to adsorb platinum nano-particles via reduction in situ on the surface of the micro-capsules of Examples 1-3.
[00198] In a 100 ml volumetric flask, 0.023 g of H2PtCl6-6H2O were dissolved in Milli-Q water up to 100 ml. 50 ml of this solution was placed in a conical flask and 1.25 ml of capsules were added and shaken vigorously for 30 min. 0.075 g of NaBH4 (Aldrich) was dissolved in 100 ml with Milli-Q water. 50 ml of this solution was added dropwise. The vigorous stirring continued for 30 min. The capsules were then washed by separation for 72 h, allowing the excess Pt to settle and the capsules to become cream. Excess Pt and water was removed using a 50 ml pipette and the capsules were redispersed in 7.5 ml of Milli-Q water. Example 9: Autocatalytic silver film formation ("electro-less plating ')
[00199] The following procedure was used to form a continuous silver film on the microcapsules of Example 5 by autocatalytic coating.
[00200] 2 ml of microcapsules were added to a beaker containing 47.5 ml of Milli-Q water. 0.5 ml of 0.1 M AgNO3 (99%, Sigma) was added and stirred vigorously. Then, 50 μl of formaldehyde (35% in H2O, Sigma) was added, followed by 26 μl of ammonia (25% in H2O, Sigma) to control the pH at ~ 10, providing a silvery gray dispersion. The dispersion was then stirred for 10 minutes, after which it was centrifuged at 4000 rpm for 10 min, 3 times, for washing, replacing the supernatant each time with Milli-Q water. Example 10: Formation of gold film by autocatalytic coating (electroless)
[00201] The following procedure was used to form a continuous gold film on the surface of the microcapsules of Examples 7 and 8 by electrocess coating (electroless). 1.58 g of HAuCl4 (99.9%, Sigma) was dissolved in 100 ml with Milli-Q water. 0.58 g of hydrogen peroxide (35% in water, Aldrich) were dissolved in 100 ml with Milli-Q water. 0.2 g of poly (vinylpyrrolidone) was dissolved in 100 ml with Milli-Q water. 1 ml of each of the above solutions was added to a 40 ml glass vial to form the coating solution. 7.5 ml of the microcapsules were added dropwise to the coating solution and stirred vigorously for 5 min. The capsules were washed by centrifugation at 4000 rpm for 5 minutes, three times. Example 11: Characterization of microcapsules containing a metallic Pt / Au coating
[00202] Coated microcapsules containing a PMMA shell, a hexadecane core and a metallic coating composed of a gold film disposed on a layer of platinum nanoparticles were prepared following the procedures described in Examples 1, 8 and 10. The coated microcapsules were then characterized using SEM and TEM.
[00203] Figure 2a is a SEM image of the uncoated PMMA microcapsules. Figure 2b is a TEM image showing the platinum nano-particles adsorbed on the outer surface of the PMMA microcapsules. Figure 2c is an SEM image showing the continuous gold film. The maximum thickness of the metallic coating was less than 200 nm in this example, but it will be appreciated that the thickness of the coating can be varied. Example 12: Characterization of microcapsules containing an Au / Ag metallic coating
[00204] Coated microcapsules containing a PEMA enclosure, a toluene core and a metallic coating composed of a silver film disposed on a layer of gold nanoparticles stabilized with borohydride were prepared following the procedures described in Examples 2, 4 , 5 and 9. The coated microcapsules were then characterized using optical microscopy, SEM, TEM and EDX.
[00205] Figure 3a is an optical micrograph showing the uncoated PEMA microcapsules. Figure 3b is a TEM image showing the gold nanoparticles stabilized with borohydride ad-adsorbed on the surface of the microcapsules. Figure 3c is an SEM image showing the continuous silver film. Figure 3d is an EDX graph of the silver film. The maximum thickness of the metallic coating was 140 nm in this example, but it will be appreciated that the thickness of the coating can be varied. Reference is made in this regard to Figures 4 and 5, which illustrate that the thickness of the metallic coating can be modified, for example, by varying the concentration of silver ions in the autocatalytic coating solution (electroless). Example 13: Characterization of microcapsules containing a metallic Pt / Au coating
[00206] Coated microcapsules containing a layer of PMMA, a core of hexyl salicylate and a metallic coating composed of a gold film disposed on a layer of platinum nanoparticles with PVP stabilized were prepared following the procedures described in Examples 3, 6, 7 and 10. The coated microcapsules were then characterized using optical microscopy, SEM and TEM.
[00207] Figure 6a is an optical micrograph showing the uncoated PMMA micro-capsules. Figure 6b is a TEM image showing the platinum nanoparticles stabilized with PVP adsorbed on the surface of the microcapsules. Figure 6c is an SEM image showing the gold film in the microcapsules. The maximum thickness of the metallic coating was less than 100 nm in this example, but it will be appreciated that the thickness of the coating can be varied. Example 14: Performance of coated microcapsules under the Ethanol Stability Test
[00208] Coated microcapsules containing a PMMA shell, a hexadecane core and a metallic coating composed of a layer of platinum nanoparticles and a continuous gold film disposed on it were prepared following the procedures described in Examples 1, 8 and 10 The coated microcapsules were then tested for their ability to retain liquid core material using the Ethanol Stability Test described here, and their performance was compared to that of uncoated PMMA microcapsules.
[00209] Figure 7a is a graph showing the performance of coated PMMA and uncoated PMMA microcapsules under the Ethanol Stability Test (see data points indicated as squares and diamonds, respectively). Also illustrated in Figure 7a is a data point obtained after the fracture of the coated PMMA microcapsules at the end of the experiment (see the data point indicated as a triangle), confirming that the liquid core material had been encapsulated. The fractured microcapsules are shown in Figure 7b. It can be seen from these data that the coated microcapsules showed negligible leakage of the liquid core material. In contrast, more than 50% of the liquid core material leaked from the uncoated microcapsules after one day. Example 15: Synthesis of microcapsules containing a formaldehyde melamine shell and a soybean oil core
[00210] The following procedure was used to prepare micro-capsules containing a melamine formaldehyde shell and a liquid core containing soybean oil. Microcapsules were prepared by an in situ polymerization process in which a copolymer of butyl acrylate-acrylic acid and poly (vinyl alcohol) were used as emulsifiers.
[00211] 0.9 g of butyl acrylate-acrylic acid copolymer (Col loid C351, 2% solids, Kemira) and 0.9 g of poly (acrylic acid) (PAA, 100 kDa, 35% in Sigma water ) were dissolved in 20 g of Mil-li-Q water. An amount of sodium hydroxide was added to this solution to adjust the pH to 3.5.
[00212] 0.65 g of partially methylated methylol melamine resin (Cymel 385, 80% solids, Cytec) and 20 g of hexyl salicylate were added while mixing at 1000 rpm for 60 minutes. In a separate container, 1.0 g of butyl acrylate - acrylic acid copolymer was mixed with 2.5 g of methylol melamine resin partially methylated in 12 g of Milli-Q water. An amount of sodium hydroxide was added to this mixture to adjust the pH to 4.6. The mixture was added to the main mixture together with 0.4 g of sodium sulfate (Sigma). The mixture was heated to 75 ° C and the temperature maintained for 6 h with continuous stirring at 400 rpm. Example 16: Synthesis of microcapsules containing a poly-acrylate shell and a core containing soybean oil and isopropyl myristate
[00213] The following procedure was used to prepare micro-capsules composed of a polyacrylate shell and a liquid core containing soybean oil and isopropyl myristate. The microcapsules were prepared by an interfacial polymerization procedure in which poly (vinylpyrrolidone) was used as an emulsifier.
[00214] 15.0 g of hexyl acetate were mixed with 3.75 g of isopropyl myristate at 400 rpm until a homogeneous solution was obtained. 15.0 g of the solution were placed in a three-necked round-bottom flask and mixed at 1000 rpm using a magnetic stirrer.
[00215] The temperature was increased to 35 ° C; then 0.06 g of 2,2-azobis-2,4-dimethylpentanonitrile (Vazo-52, Du Pont) and 0.02 g of 2,2-azobis (2-methylbutyronitrile) (Vazo -67, Du Pont) were added to the reactor, with a blanket of nitrogen applied at 100 cm3.min-1. The temperature was raised to 75 ° C and maintained for 45 minutes before being cooled slowly to 60 ° C.
[00216] The remaining oil-myristate solution was mixed with 0.05 g of t-butylaminoethyl methacrylate (Sigma), 0.04 g of 2-carboxyethyl acrylate (Sigma) and 1.95 g of acrylate oligomer. hexafunctional aromatic urethane (CN9161, Sartomer) at 400 rpm, until homogeneous. The mixture was degassed using nitrogen. At 60 ° C, this mixture was added to the reaction vessel and held at 1000 rpm at 60 ° C for 10 minutes, before stirring was stopped.
[00217] 2.0 g of poly (diallyl dimethyl ammonium chloride) (pDADMAC, 32% active, Sigma) were dissolved in 23.6 ml of Milli-Q water. 0.11 g of 20% sodium hydroxide solution, and then 0.12 g of 4,4-azobis (cyanovaleric acid) (Vazo-68 WSP, Du Pont) were added and stirred at 400 rpm until it dissolved .
[00218] The oil-monomer solution was added to the pDADMAC solution. The mixing was then resumed at 1000 rpm for 60 minutes. The mixture was then slowly heated to 75 ° C and maintained at this temperature for 12 h with stirring at 400 rpm. Example 17: Preparation of charge-stabilized gold nanoparticles
[00219] The following procedure was used to prepare gold nano-particles stabilized with borohydride.
[00220] 0.036 g of HCl were dissolved in Milli-Q water in a 25 ml volumetric flask. The HAuCl4 and HCl solutions were combined in a separate flask. 1.25 ml of this mixture was added dropwise to 47.25 ml of Milli-Q water and stirred vigorously. A borohydride solution was prepared by adding 0.095 g of NaBH4 dissolved in 25 ml of Milli-Q water, to 0.1 g of NaOH dissolved in 25 ml of Milli-Q water. 1.5 ml of this mixture was added in one go, and the solution was stirred for 1 minute. The solution changed color from pale yellow to dark ruby red, indicating the formation of Au nanoparticles. Example 18: Adsorption of charge-stabilized gold nanoparticles in microcapsules
[00221] The following procedure was used to adsorb the charge-stabilized gold na-noparticles of Example 17 onto the surface of the microcapsules of Examples 15 and 16.
[00222] 5 ml of the Au nanoparticles were added to a baby and shaken vigorously. 2 ml of microcapsules were added dropwise, and stirred vigorously for another 10 minutes. The microcapsules were collected by centrifugation (Heraeus Mega-fuge R16) and removal of the supernatant four times at 4000 rpm for 10 min, to remove excess nanoparticles, and were then re-dispersed in water (20 ml). Example 19: Silver film formation by electroless coating (electroless)
[00223] The following procedure was used to form a continuous silver film on the microcapsules of Example 18 by autocatalytic (electroless) coating.
[00224] 5 ml of microcapsules were added to a beaker containing 30 ml of Milli-Q water. 0.5 ml of 0.1 M AgNO3 (99%, Sigma) was added and stirred vigorously. 50 μl of formaldehyde (35% in H2O, Sigma) was then added, followed by 26 μl of ammonia (25% in H2O, Sigma) to control the pH to ~ 10, providing a silvery gray dispersion. The dispersion was then stirred for 10 minutes, after which it was centrifuged at 4000 rpm for 10 min, 3 times, for washing, replacing the supernatant each time with Milli-Q water. Example 20: Characterization of microcapsules containing a melamine formaldehyde shell and an Au / Ag metallic coating
[00225] Coated microcapsules containing a formaldehyde melamine casing, a soy oil core and a metallic coating composed of a silver film arranged on a layer of gold nanoparticles stabilized with borohydride were prepared following the procedures described in the Examples 15 and 17-19. The coated microcapsules were then characterized using optical microscopy, SEM, TEM and EDX.
[00226] The coated microcapsules were then tested for their ability to retain the liquid core material using the Ethanol Stability Test described here, and their performance was compared to that of uncoated melamine-formaldehyde microcapsules. While the coated microcapsules showed insignificant leakage of the liquid core material, more than 50% of the liquid core material leaked from the uncoated microcapsules after one day. Example 21: Characterization of microcapsules containing a polyacrylate shell and an Au / Ag metallic coating
[00227] Coated microcapsules containing a polyacrylate shell, a core containing hexyl acetate and isopropyl myristate and a metallic coating composed of a silver film disposed on a layer of gold nanoparticles stabilized with boron hydride were prepared following the procedures described in Examples 16-19. The coated microcapsules were then characterized using optical microscopy, SEM, TEM and EDX.
[00228] The coated microcapsules were then tested for their ability to retain the liquid core material using the Ethanol Stability Test described here, and their performance was compared to that of uncoated polyacrylate microcapsules. While the coated microcapsules showed negligible leakage of the liquid core material, more than 50% of the liquid core material leaked from the uncoated microcapsules after one day. Example 22
[00229] A gold coating is placed on the surface of a perfume microcapsule with a melamine formaldehyde wall (MF-PMC). There are usually two steps. The first step is the addition of Pt to coat the surface of the MF-PMC. The second step is the addition of Au to the surface of the MF-PMC coated with Pt. Finally, scanning electron microscopy (SEM) images are provided.
[00230] MF-PMC is generally manufactured in accordance with US 8,940,395 and available from Appleton Papers Inc. (USA). MF-PMC is supplied as a spray dried powder. The fracture strength data for these MF-PMCs is 1-3 MPa, measured before being spray dried to powder. It is not known whether spray drying affects fracture resistance. The target particle size for MF-PMC is 18 microns (volume-weighted median particle size), that is, the largest number of MF-PMC (by volume) has a particle size of 18 microns.
[00231] The first step is performed as an in situ reduction approach or as a sterically stabilized Pt nanoparticle adsorption approach. The in situ approach is described. Addition of Pt to the surface of the MF-PMC is described. 500 mg of MF-PMC particles are dispersed in 20 g of water and are sonicated for 30 minutes to suspend the particles and break up aggregates. 0.23 g of H2PtCl6 are dissolved in 100 ml of water. 0.076 g of NaBH4 are dissolved in 100 ml of water. 2 ml of MF-PMC dispersion is added to 25 ml of H2PtCl6 solution and stirred for 30 minutes. 25 mL of NaBH4 is then added and stirred using a magnetic stirrer for an additional 90 minutes. The resulting suspension is centrifuged (4000 rpm for 10 min) and washed with 25 ml of distilled water. The process is repeated 2 more times.
[00232] The adsorption approach is described. First, a suspension of Pt nanoparticles is made. 0.23 g of H2PtCl6 are dissolved in 100 ml of poly (vinylpyrrolidone) ("PVP") (1.56 µM), 0.4 ml of NaBH4 (0, 2 M) are added and the suspension is stirred at high speed for 2 minutes. The nanoparticle suspension is then left to stand overnight. Second, the nanoparticle suspension is added to the MF-PMC. 500 mg of the MF-PMC particles are dispersed in 20 g of water and sonicated for 30 minutes to suspend particles and break up aggregates. 5 mL of the Pt nanoparticle suspension is diluted with an additional 5 mL of water. 1 ml of the MF-PMC particle suspension is added to the diluted Pt nanoparticle suspension. The combined suspensions are left stirring for 60 minutes on a merry-go-round. Then, the resulting suspension is centrifuged (4000 revolutions per minute (rpm) for 10 minutes) and washed with 25 ml of distilled water. The process is repeated 2 more times.
[00233] The second step of coating the MF-PMC surface coated with Au with Pt can be described. This second stage is the same regardless of the approach used in the first stage. 1 ml of HAuCl4 (40mM), 1 ml of H2O2 (60 mM) and 3 ml of PVP (0.2% by weight) are added to a glass vial. 1 ml of MF-PMC coated with nanoparticles is added to the flask and the mixture stirred on a merry-go-round for 10 minutes. The resulting suspension is centrifuged (4000 rpm for 5 minutes) and washed with 25 ml of distilled water. The process is repeated 2 more times.
[00234] As can be seen in the SEM images of Figures 8 and 9, a gold coating is obtained for the MF-PMC. Figure 8 is the in situ reduction approach, ostensibly obtaining a complete gold coating. Figure 9 is the PVP-stabilized approach where the surface of the MF-PMC gets a gold coating.
[00235] All percentages, parts and reasons cited here are calculated by weight, unless otherwise stated. All percentages, parts and ratios are calculated based on the total composition, unless otherwise stated. Unless otherwise stated, all levels of component or composition are in reference to the active portion of that component or composition and exclude impurities, for example, residual solvents or by-products that may be present in commercially available sources of such components or compositions.
[00236] It should be understood that each maximum numerical limitation given throughout this report includes all lower numerical limitations, as if such lower numerical limitations were expressly written here. Any minimum numerical limitations given throughout this report will include all the highest numerical limitations, as if those higher numerical limitations were expressly written here. Any numeric range provided throughout this report will include each narrower numeric range that falls within a broader numeric range, as if such narrower numeric ranges were expressly written here.
[00237] The dimensions and values disclosed herein should not be understood as being strictly limited to the exact numerical values cited. Instead, unless otherwise specified, each of these dimensions is intended to mean the quoted value and a functionally equivalent range around that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".
[00238] Any document cited herein, including any referenced or related patent or cross-application and any patent or patent application to which this application claims priority or benefit, is hereby incorporated by reference in its entirety, unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art in relation to any invention disclosed or claimed in this document or that it alone, or in any combination with any other reference or references, teach, suggest or disclose any such an invention. In addition, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document must prevail.
[00239] Although particular embodiments of the present invention have been illustrated and described, it should be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Thus, it is intended to cover in the appended claims all changes and modifications that are within the scope of this invention.

权利要求:
Claims (17)
[0001]
1. Coated microcapsule, characterized by the fact that it comprises: a microcapsule comprises of a polymeric shell and a liquid core material encapsulated therein; and a metallic coating surrounding said microcapsule; wherein the metallic coating comprises particles of a first metal adsorbed on said polymeric shell and a film of a second metal formed thereon; and where the metallic coating has a maximum thickness of 1000 nm.
[0002]
2.Microcapsule coated according to claim 1, characterized by the fact that the liquid core material comprises one or more active ingredients; preferably in which the one or more active ingredients are selected from the group consisting of perfumes; rinse aid; insect repellents; silicones; waxes; flavorings; vitamins; fabric softening agents; depilatory agents; skin care agents; enzymes; probiotics; polymer-dye conjugate; clay-dye conjugate; perfume transfer system; sensing agents, more preferably a cooling agent; attractive, more preferably a pheromone; antibacterial agents; dyes; preferably lactones, indolyl red, 16B, leuco dyes; pigments; bleaches; flavorings; sweeteners; waxes; essential oils, more preferably pine oil, cinnamon oil, clove oil, lemon oil, lime oil, orange oil, peppermint oil and the like; and mixtures thereof.
[0003]
3.Microcapsule coated according to claim 1 or 2, characterized in that the liquid core material includes a volatile material, for example, a volatile oil; preferably the volatile material being a perfume oil; more preferably the total amount of perfume raw materials in the liquid core material is from 0.1 to 100% by weight of the liquid core material, for example, from 10 to 80% by weight, for example, from 20 to 70% in weight.
[0004]
A coated microcapsule according to any one of claims 1 to 3, characterized in that the liquid core material includes one or more compounds selected from isopropyl myristate, C4-C24 fatty acid triesters, soybean oil, ester methyl of hexadecanoic acid and isododecane.
[0005]
A coated microcapsule according to any one of claims 1 to 4, characterized in that the polymeric shell comprises a polymeric material selected from the group consisting of polyacrylates, polyethylenes, polyamides, polystyrenes, polyisoprene, polycarbonates, polyesters, polyureas, polyurethanes , polyolefins, polysaccharides, epoxy resins, vinyl polymers, urea crosslinked with formaldehyde or glutaraldehyde, crosslinked melamine with formaldehyde, gelatin-polyphosphate coacervates, optionally cross-linked with glutaraldehyde, gelatin-gum coacervates, silicone fluids, silicone fluids polyisocyanates, acrylate monomers polymerized via free radical polymerization, silk, wool, gelatin, cellulose, alginate, proteins and combinations thereof; preferably, the polymeric shell comprises a polyacrylate; more preferably, the polyacrylate is poly (methyl methacrylate) or poly (ethyl methacrylate).
[0006]
6.Microcapsule coated according to any one of claims 1 to 5, characterized by the fact that the polymeric shell can be obtained by polymerizing a precursor material selected from: melamine-formaldehyde resins; urea-formaldehyde resins; monomeric or low molecular weight polymers of methylol melamine; monomeric or low molecular weight polymers of dimethylol urea or methylated dimethylolurea; and partially methylated methylol melamine; preferably, the polymeric shell can be obtained by polymerizing a precursor material selected from melamine-formaldehyde resins and urea-formaldehyde resins.
[0007]
A coated microcapsule according to any one of claims 1 to 6, characterized in that the polymeric shell includes a surface modifying agent; preferably in which at least some of said particles are adsorbed on said surface modifying agent.
[0008]
8.Microcapsule coated according to claim 7, characterized by the fact that the surface modifying agent is a polymer or surfactant; preferably, the surface modifying agent is selected from cetyl trimethylammonium bromide (CTAB), poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) and mixtures thereof.
[0009]
9.Microcapsule coated according to any one of claims 1 to 8, characterized in that the particles of the first metal are nanoparticles; preferably wherein said nanoparticles have a particle size of less than 100 nm, for example, less than 50 nm, for example, 10 nm, for example, less than 5 nm, for example, less than 3 nm.
[0010]
A coated microcapsule according to any one of claims 1 to 9, characterized in that the first metal is palladium, platinum, silver, gold, copper, nickel, tin or a combination thereof; and where the second metal is silver, gold, nickel, copper or a combination thereof.
[0011]
A coated microcapsule according to any one of claims 1 to 10, characterized in that the density of said particles in the polymeric shell is such that said particles cover from 0.1 to 80% of the surface area of the polymeric shell, for example , from 0.5 to 40% of the surface area of the polymeric shell, for example, from 1 to 4% of the surface area of the polymeric shell.
[0012]
12.Microcapsule coated according to any one of claims 1 to 11, characterized by the fact that: (i) the first metal is platinum and the second metal is gold; (ii) the first metal is gold and the second metal is silver; or (iii) the first metal is gold and the second metal is copper.
[0013]
13.Microcapsule coated according to any one of claims 1 to 12, characterized in that the metallic coating has a maximum thickness of 500 nm, for example, a maximum thickness of 300 nm, for example, a maximum thickness of 150 nm, for example, a maximum thickness of 100 nm, for example, a maximum thickness of 50 nm; and wherein the metallic coating has a minimum thickness of 1 nm, for example, a minimum thickness of 5 nm, for example, a minimum thickness of 10 nm, for example, a minimum thickness of 20 nm.
[0014]
A coated microcapsule according to any one of claims 1 to 13, characterized in that the coated microcapsule has a particle size of 0.1 micron to 500 microns, for example, from 1 micron to 100 microns, for example, from 1 to 30 microns, for example, from 1 micron to 20 microns.
[0015]
The coated microcapsule according to any one of claims 1 to 14, characterized in that the coated microcapsule has a fracture resistance of 0.1 MPa to 25 MPa, for example, from 0.5 MPa to 25 MPa, for example , from 0.5 MPa to 20 MPa, for example, from 0.5 MPa to 15 MPa.
[0016]
16. Consumer product, characterized by the fact that it comprises coated microcapsules, as defined in any one of claims 1 to 15, which is selected from the group consisting of products for hair treatment (hair); personal cleaning products; color cosmetics; skin care products; deodorants and antiperspirants; products for orally administered materials to improve the appearance of hair, skin and / or nails; products for treating fabrics, hard surfaces and any other surfaces in the area of fabric and housewares, products related to disposable absorbent and / or non-absorbent articles, hand soaps, shampoos, lotions, oral care implements and clothing; products such as dry or wet paper towels, facial paper towels, disposable tissues, towels and or disposable cleaning cloths; products related to menstrual pads, incontinence pads, interlabial pads, panty protectors, pessaries, sanitary pads, tampons and cleaning pads and / or cleaning pads; preferably the hair care product is selected from the group consisting of bleaching products, coloring products, dyeing products, conditioning products, growth products, removal products, growth retardation products, washing (shampoo), hair styling products; or where the product for treating fabrics, hard surfaces and any other surfaces in the fabric and housewares area is selected from the group consisting of air care products, car care products, dishwashing products, cleaning products fabric conditioning including fabric softening products, laundry detergent products, additives and / or care products for washing and rinsing clothes, hard surface cleaning products; or where the product related to disposable absorbent and / or non-absorbent items is selected from the group consisting of adult incontinence garments, bibs, diapers, training pants, baby wipes for babies and young children.
[0017]
17. Use of coated microcapsules, as defined in any one of claims 1 to 15, characterized by the fact that it is for incorporation into a consumer product; where the consumer product is selected from the group consisting of hair care products (hair); personal cleaning products; color cosmetics; skin care products; deodorants and antiperspirants; products for orally administered materials to improve the appearance of hair, skin and / or nails; products for treating fabrics, hard surfaces and any other surfaces in the area of fabric and housewares, products related to disposable absorbent and / or non-absorbent articles, hand soaps, shampoos, lotions, oral care implements and clothing; products such as wet or dry paper towels, facial paper towels, disposable handkerchiefs, disposable towels and / or cleaning cloths; products related to menstrual pads, incontinence pads, interlabial pads, panties protectors, pessaries, sanitary pads, tampons and tampon applicators and / or cleaning wipes.

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法律状态:
2018-06-12| B25A| Requested transfer of rights approved|Owner name: NOXELL CORPORATION (US) |

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2019-11-12| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2020-12-01| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

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2021-01-19| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 16/12/2015, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

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申请号 | 申请日 | 专利标题

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US201462092613P| true| 2014-12-16|2014-12-16|

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US62/092,613|2014-12-16|

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PCT/US2015/066043|WO2016100479A1|2014-12-16|2015-12-16|Coated microcapsules|

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