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    • 专利摘要:
    As the coating film forming component, an epoxy group-containing vinyl copolymer (A) having a glass transition temperature of 40 ° C or higher, an epoxy group-containing vinyl copolymer (B) having a glass transition temperature of O ° C or lower, and a polyhydric carboxylic acid (C) are essential components. Spray-drying the organic solvent solution it contains provides the thermosetting powder coating of 0.90 or more of average circularity, 0.98-1.00 of the roundness of a modest particle, and an average particle diameter of 5-50 micrometers.
    公开号:KR20020096881A
    申请号:KR1020020030553
    申请日:2002-05-31
    公开日:2002-12-31
    发明作者:아가와데쓰로；오카다가쓰히코；다나카히로오；하시모토마사야；아사쿠라다카아키
    申请人:다이니혼 잉키 가가쿠 고교 가부시키가이샤；가부시키가이샤 리퀴드 가스；
    IPC主号:
    专利说明:

    Thermosetting Powder Coatings & Coatings {THERMOCURABLE POWDER COATING COMPOSITION, METHOD OF PREPARATION THEREOF AND COATED ARTICLE THEREWITH}
    [3] The present invention provides a thermosetting powder coating which is excellent in fluidity, paintability, and the like, and in particular, can provide a coating film having excellent smoothness, finish appearance, and also scratch resistance when forming a thin film, and a coating material obtained using the same. It is about.
    [4] Powder coatings are environmentally compatible paints that do not volatilize organic solvents into the air during painting, and are widely used throughout metal coatings. Among them, thermosetting powder coatings have been recognized for their excellent coating performance and have been applied to various applications.
    [5] However, in the case of conventional powder coating, in order to obtain an appearance equivalent to that of a solvent type, it is necessary to set a high curing temperature due to a relatively high film thickness, which is a big problem in the industry. For example, in the industrial field requiring painting such as the automobile industry and the steel making industry, from the viewpoint of low cost and light weight, the surface appearance is good with a thin film, but the development of powder coating that maintains stable quality even after continuous coating is strongly developed. It is required.
    [6] Moreover, in the coating method by the melt kneading method which is generally adopted as a manufacturing method of the powder coating, in order to improve the smoothness at the time of thin film, the particle | grains of paint are researched for the diameter of small particle, but the size of the small particle Since mechanical pulverization is employed as a method, the coating cost is high, and in addition, it is difficult to control the particle diameter and the particle shape, and therefore, there is a problem that it is very difficult to achieve good paintability and coating appearance.
    [7] Regarding this problem, a composition for powder coating having excellent finish appearance and a coating method thereof are disclosed in US Pat. No. 5,948,866. When the powder coating composition is used, a coating film having excellent finish appearance and scratch resistance can be obtained, and in view of its characteristics, such as for automobile top clears, which has been difficult to use powder coating due to problems of appearance appearance in thin films. It is disclosed that development to a use is also promising.
    [8] However, the powder coating composition is certainly good in finish appearance and scratch resistance as compared with the conventional powder coating, but since the preparation is performed by melt kneading method, fluidity, coating workability, storage of the powder coating There is room for further improvement in stability.
    [9] Specifically, the melt kneading method is used to mix raw materials such as resins, hardeners, plasticizers, stabilizers, flow regulators, pigments and fillers using high-speed mixers such as Henschel mixers, and then high shear such as extruders. In the mixer, the mixture is melt-kneaded to become a complete dispersion of each raw material, cooled, mechanically pulverized, powdered, classified and powdered.
    [10] Since it is manufactured through such a process, the homogeneous mixing property of each component, such as a thermosetting resin and a hardening | curing agent, is insufficient, and when it is a small particle, the particle size distribution of pulverized particle | grains spreads easily, Furthermore, since the particle shape becomes amorphous, fluidity of powder coating This is deteriorated, and it is easy to adversely affect the coating workability, storage stability, etc. of powder coating, and it has a problem that it becomes easy to cause the fall of a coating film especially at the time of thin film formation.
    [11] The problem to be solved by the present invention is excellent in fluidity and coating workability of the powder coating, and excellent in smoothness and finish appearance even when the obtained coating film is particularly small, such as a thin film of 50 μm or less, In addition, the present invention provides a powder coating and its coating having excellent scratch resistance.
    [1] 1 is a graph showing a circular distribution chart of the powder coating material obtained in Example 1. FIG.
    [2] 2 is a graph showing a circularity distribution diagram of the powder coating obtained in Comparative Example 1. FIG.
    [12] MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the above-mentioned subject, the present inventors consisted of the particle | grains containing a specific component as a coating film formation component, the average particle diameter of the whole particle | grain is 5-50 micrometers, and the average circularity of the particle | grains is carried out. The coating film formed by using the thermosetting powder coating, characterized in that the circularity of particles having a maximum number frequency in the circularity distribution is 0.90 or more and the circularity distribution is 0.98 to 1.00. It was found that the smoothness of was particularly excellent, and that the powder coating had excellent fluidity and electrostatic coating property, and the like, thus completing the present invention.
    [13] That is, this invention is an epoxy group containing vinyl copolymer (A) which has a glass transition temperature of 40 degreeC or more, an epoxy group containing vinyl copolymer (B) which has a glass transition temperature of 0 degrees C or less as a coating film formation component, and polyvalent. It is composed of particles containing carboxylic acid (C) as an essential component, and the average particle diameter of the whole particle is 5 to 50 µm, the average circularity of the particles is 0.90 or more, and the largest number in the circularity distribution. I) A thermosetting powder coating, characterized in that the circularity of particles having a frequency is 0.98 to 1.00, and a coating material formed by coating the powder coating by thermal curing on a coated object to form a coating film.
    [14] Moreover, this invention contains as an essential component an epoxy group containing vinyl copolymer (A) which has a glass transition temperature of 40 degreeC or more, an epoxy group containing vinyl copolymer (B) and a polyhydric carboxylic acid (C) which have a glass transition temperature of 0 degrees C or less. A thermosetting powder coating having the above characteristics is obtained by spray drying a powder coating raw material solution.
    [15] The coating material and the coating material by the structure of this invention are excellent in the smoothness and abrasion resistance in a thin film, and also excellent in fluidity | liquidity and coating workability with respect to paint.
    [16] Hereinafter, the details of the present invention will be described in detail.
    [17] First, the particle shape of powder coating which is one of the characteristics of the powder coating of this invention is demonstrated.
    [18] The powder coating of the present invention is characterized by first having an average particle diameter of 5 to 50 µm. In addition, the average particle diameter is preferably in the range of 10 to 30 µm from the viewpoint of making the appearance of the thin film more excellent. The average particle diameter means a volume average median diameter, and can be measured, for example, by a laser diffraction particle size measuring apparatus (SALD-2000) manufactured by Shimadzu Corporation.
    [19] Moreover, the powder coating of this invention is substantially spherical, the average circularity is 0.9O or more, and the circularity of the particle which has the largest number frequency in the circularity distribution is 098-1.00. Thus, by making a particle shape substantially spherical shape, the effect of the outstanding fluidity | liquidity and coating workability which are the subject of this invention are exhibited. From this point of view, the particle size of 0.90 or more is preferably 50% or more, and more preferably 70% or more.
    [20] The circularity and average circularity here are one of the particle shape indices which show the uneven | corrugated state of a particle surface, and are represented as follows.
    [21] Circularity = (circle of the same area as the particle projection area) / (perimeter of the particle projection image)
    [22] Therefore, the circularity becomes 1 when the particle shape is a round shape, and becomes smaller as the particle shape deviates from the circle shape and is elongated or rugged. The average circularity is obtained by dividing the sum of the circularities of each particle by the total number of particles.
    [23] The shape and average circularity of the powder coating can be measured by a flow particulate analysis device (FPIA-1000, manufactured by Toyo Denko Co., Ltd.). In addition, the shape of the powder coating can also be confirmed by a scanning electron microscope.
    [24] In addition, "the circularity of the particle which has the largest number frequency in circularity distribution" means that circularity 0.40-1.00 of particle | grains are divided into 61 in the circularity frequency distribution calculated | required by the said measurement, and each section (circularity figure) 0.01 width) refers to the circularity of the section in which the frequency of the number is the maximum.
    [25] Next, each raw material used to manufacture the powder coating of the present invention will be described.
    [26] As a raw material of the powder coating of the present invention, an epoxy group-containing vinyl copolymer (A) having a glass transition temperature of 40 ° C. or higher as a thermosetting resin, that is, a main resin, and an epoxy group having a glass transition temperature of 0 ° C. or lower The containing vinyl copolymer (B) is used and polyhydric carboxylic acid (C) is used as its hardening | curing agent. By using these compositions as a raw material of powder coating, the finish appearance and scratch resistance of the coating film obtained are favorable.
    [27] The epoxy group-containing vinyl copolymer (A) having a glass transition temperature of 40 ° C or higher refers to a vinyl copolymer having an average of two or more epoxy groups in one molecule and a glass transition temperature of 40 ° C or higher. The glass transition temperature can be measured by differential scanning calorimetry and is determined as the initial inflection point at a heating rate of 10 ° C. for 1 minute.
    [28] A known conventional method may be used to prepare the epoxy group-containing vinyl copolymer (A). However, an epoxy group-containing compound and other copolymerizable vinyl monomers may be used, if necessary, to polymerize each of these monomers in an organic solvent. The method is preferred because it is the simplest. In that case, a well-known conventional thing can be used as it is as a polymerization initiator and a solvent.
    [29] When the epoxy group containing vinyl monomer used in preparation of an epoxy group containing vinyl copolymer (A) is illustrated, glycidyl (meth) acrylate, (beta) -methyl glycidyl (meth) acrylate, glycidyl vinyl ether, and allyl Various epoxy group-containing monomers such as glycidyl ether; Vinyl monomers containing (2-oxo-1,3-oxolane) groups such as (2-oxo-1,3-oxolane) methyl (meth) acrylate; Various alicyclic epoxy group-containing vinyl monomers such as 3,4-epoxycyclohexyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and 3,4-epoxycyclohexylethyl (meth) acrylate Can be mentioned.
    [30] As other vinyl monomers copolymerizable with such an epoxy group-containing vinyl monomer, (meth) acrylic acid, crotonic acid or esters thereof, and various known ethylenically unsaturated bond-containing monomers can also be used. These may be used independently and may be used together 2 or more types.
    [31] Examples of the ester of the above-mentioned (meth) acrylic acid include those particularly exemplified by methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid -Butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate or n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, Alkyl (meth) acrylates, such as isooctyl (meth) acrylate, 2-ethyl octyl (meth) acrylate, dodecyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate or stearyl (meth) acrylate Esters,
    [32] Benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate or tetrahydropulfuryl (meth) acrylate,
    [33] Or various alkyl carbitol (meth) acrylates such as ethyl carbitol (meth) acrylate, and the like, and further, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) ) Acrylate or dicyclopentenyloxyethyl (meth) acrylate;
    [34] Hydroxyl-containing (meth) acrylic acid esters, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc .:
    [35] Polyethyleneglycol mono (meth) acrylate or polypropylene glycol mono (meth) acrylate, and the like, and various hydroxyl-containing (meth) acrylic acid esters as described above, and are so-called lactone-modified forms of ring-opening reaction of -Caprolactone. Hydroxyl group-containing (meth) acrylate; and the like.
    [36] Moreover, if it limits only what is specifically represented as another ethylenically unsaturated monomer, For example, (gamma)-(meth) acryloyloxypropyl trimethoxysilane and (gamma)-(meth) acryloyloxypropyl triethoxy Various hydrolyzable silyl group-containing monomers such as silane or γ- (meth) acryloyloxypropylmethyldimethoxysilane;
    [37] Various fluorine-containing α-olefins such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, detrafluoroethylene, chlorotrifluoroethylene, bromotrifluoroethylene, pentafluoropropylene or hexafluoropropylene:
    [38] Or perfluoroalkyl perfluorovinylether or (per) fluoroalkylvinyl, such as trifluoromethyltrifluorovinylether, pentafluoroethyltrifluorovinylether or heptafluoropropyltrifluorovinylether Various fluorine-containing vinyl monomers such as ethers (where the alkyl group has a carbon number in the range of 1 to 18), or the like, or
    [39] Furthermore, phosphate ester group containing vinyl monomers, such as mono [(meth) acryloyloxyethyl] phosphate, acidic phosphoric acid (meth) acrylic acid ester, or (meth) acryloyloxyethyl phosphate phenyl;
    [40] Mono- or diesters of various polyhydric carboxyl group-containing monomers represented by fumaric acid, maleic acid or itaconic acid, and monoalkyl alcohols having 1 to 18 carbon atoms; Various aromatic vinyl compounds such as styrene, vinyltoluene, α-methylstyrene or p-tert-butylstyrene;
    [41] (Meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-iso-propyl (meth) acrylamide, Nn-butyl (meth) Acrylamide, N-iso-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-amyl (meth) acrylamide, N- (meth) acrylamide, N-hexyl (meth) acrylamide , N-heptyl (meth) acrylamide or N-2-ethylhexyl (meth) acrylamide,
    [42] N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl ( Meta) acrylamide, Nn-propoxymethyl (meth) acrylamide, N-iso-propoxymethyl (meth) acrylamide or Nn-butoxymethyl (meth) acrylamide,
    [43] Or N-iso-butoxymethyl (meth) acrylamide, N-tert-butoxymethyl (meth) acrylamide, N-amyloxymethylacrylamide, N-hexyloxy (meth) acrylamide, N-heptyloxy Various amino group-containing amide vinyl monomers such as methyl (meth) acrylamide, N-octyloxymethyl (meth) acrylamide, N-2-ethyl-hexyloxymethyl (meth) acrylamide or diacetone (meth) acrylamide ;
    [44] Various dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate or diethylaminoethyl (meth) acrylate: tert-butylaminoethyl (meth) acrylate and tert-butylaminopropyl (meth) ) Acrylate, aziridinylethyl (meth) acrylate, pyrrolidinylethyl (meth) acrylate, piperidinylethyl (meth) acrylate, (meth) acryloyl morpholine, N-vinyl 2-pyrroli Various nitrogen-containing vinyl monomers such as don, N-vinylcaprolactam, N-vinyloxazoline or (meth) acrylonitrile;
    [45] Vinyl acetate and vinyl propionate, lactate, vinyl, isopropyl lactate, vinyl caproate, vinyl caprylate, vinyl capric acid, vinyl laurate, vinyl, C 9 is branched (branched) aliphatic carboxylic acids, vinyl C 10 is branched Various aliphatic vinyl carboxylates, such as (branched) aliphatic vinyl carboxylate, C 11 branched (branched) aliphatic carboxylic acid vinyl or vinyl stearate:
    [46] Vinyl esters of various carboxylic acids having a cyclic structure such as vinyl cyclohexanecarboxylic acid, vinyl methylcyclohexanecarboxylic acid, vinyl benzoate or vinyl p-tert-butylbenzoate;
    [47] Various alkyl vinyl ethers such as ethyl vinyl ether, hydroxyethyl vinyl ether, hydroxy n-butyl vinyl ether, hydroxyisobutyl vinyl ether, cyclohexyl vinyl ether or lauryl vinyl ether;
    [48] Various halogenated olefins other than the above-mentioned fluoroolefins, such as vinyl chloride or vinylidene chloride, or various alpha-olefins, such as ethylene, propylene, butene-1, etc. are mentioned.
    [49] As a radical polymerization initiator used at the time of preparation of the said epoxy group containing vinyl copolymer (A), various well-known conventional compounds can be used.
    [50] Representative examples of them include 2,2'-azobisisobutyronitrile, 2,2'-azobis-methylbutylnitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1, 1'-Azobis-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanogilacetic acid, 2.2'-azobis- (2-amidinopropene ) Dihydrochloride, 2-tert-butylazo-2-cyanopropane, 2,2'-azobis (2-methyl-propionamide) dihydrate, 2,2'-azobis [2- (2-imida Zolin-2-yl) propene] or 2,2'-azobis (2.2,4-trimethylpentane);
    [51] Or benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, potassium persulfate, tert-butylperoxy neodecanoate, tert-butylperoxy pivalate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyisobutyrate, 1,1-bis-tert-butylperoxy-3,3,5-trimethylcyclohexane or tert-butylperoxy-laurate, tert-butylperoxyisophthalate, tert-butyl Various ketone peroxides such as peroxyacetate, tert-butylperoxybenzoate, dicumylperoxide or di-tert-butylperoxide; Peroxyketals; Hydroperoxides; Dialkyl peroxides; Diacyl peroxides; Peroxy esters: peroxydicarbonates; Or hydrogen peroxide.
    [52] As an organic solvent used in preparation of an epoxy-group-containing vinyl copolymer (A), a well-known conventional organic solvent can be used.
    [53] Typical examples of such organic solvents include alkyl alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol and isopentanol:
    [54] Methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether Same glycol ethers;
    [55] Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene: mixed hydrocarbons containing aromatic hydrocarbons such as Exon Aromatic Naphtha No. 2 (manufactured by Exxon, USA); aliphatic hydrocarbons such as n-pentane, n-hexane, n-octane; Mixed hydrocarbons containing aliphatic hydrocarbons such as isopa C, isopa E, Axol DSP10 / 140, Axol D3O (all of which are manufactured by Exxon Corporation), and IP Solvent 1016 (manufactured by Idemitsu Chemical Co., Ltd.); Alicyclic hydrocarbons such as cyclotentan, cyclohexane, methylcyclohexane, ethylcyclohexane;
    [56] Ethers such as tetrahydrofuran, dioxane, diisopropyl ether and di-n-butyl ether: ketones such as acetone, methyl ethyl ketone, methyl and isobutyl ketone; Esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, hexyl acetate, ethyl propionate and butyl propionate. Moreover, a small amount of water can also be used together with the said organic solvent.
    [57] Moreover, although it is also possible to use a chain transfer agent as needed, if it limits only to what is especially representative among them, dodecyl mercaptan, lauryl mercaptan, thioglycolic acid ester, mercaptoethanol, or (alpha) -methylstyrene dimer And so on.
    [58] The epoxy group-containing vinyl copolymer (A) used in the present invention has a glass transition temperature of 40 ° C. or higher, but from the viewpoint of making the storage stability of the powder coating composition and the smoothness of the coating film more excellent, this glass transition temperature is The range of 50-90 degreeC is more preferable, Furthermore, the range of 60-80 degreeC is preferable. When glass transition temperature is less than 40 degreeC, since the problem arises in the storage stability of the powder coating composition obtained, it is unpreferable.
    [59] The number average molecular weight of the epoxy group-containing vinyl copolymer (A) having a glass transition temperature of 40 ° C. or higher is preferably in the range of about 1, OOO to about 10O, OOO, and more preferably in the range of 1.500 to 6.000.
    [60] Moreover, about 250 to about 1000 are preferable, and, as for the epoxy equivalent in this epoxy group containing vinyl copolymer (A), it exists in the range of 300-600 more preferably.
    [61] Next, the epoxy group-containing vinyl copolymer (B) having a glass transition temperature of 0 ° C. or lower used in the present invention will be described. In preparing the epoxy group-containing vinyl copolymer (B), a known and common method can be applied as in the epoxy group-containing vinyl copolymer (A). Epoxy group-containing vinyl monomers that can be used for the epoxy group-containing vinyl copolymer (A), and other copolymerizable vinyl monomers are also used, if necessary, and the method of polymerizing these monomers in an organic solvent is the simplest. Because it is recommended. In that case, a well-known conventional thing can be used as it is as a polymerization initiator and a solvent to be used.
    [62] The epoxy group containing vinyl monomer, other vinyl monomer, and radical polymerization initiator which were illustrated as what can be used at the time of preparation of the epoxy group containing vinyl copolymer (A) mentioned above also when preparing an epoxy group containing vinyl copolymer (B). A chain transfer agent can be used, respectively.
    [63] Although the epoxy group containing vinyl copolymer (B) used by this invention has a glass transition temperature of 0 degrees C or less, this glass transition temperature is -5 from a viewpoint that the scratch resistance and smoothness of a coating film can be made more excellent. The range of -80 degreeC is more preferable, Furthermore, the range of -10-50 degreeC is preferable. When glass transition temperature is 0 degreeC or more, since the problem easily arises in the scratch resistance of the coating film obtained, it is unpreferable.
    [64] Moreover, it is preferable that the epoxy equivalent of an epoxy-group-containing vinyl copolymer (B) is 1500 or less from a viewpoint that it can ensure stability with time from the outstanding characteristics, such as the scratch resistance of the coating film obtained using the powder coating composition of this invention, It is more preferable that it is 800 or less.
    [65] Moreover, as a number average molecular weight of an epoxy-group-containing vinyl copolymer (B), the inside of the range of about 2,000 to about 20, OO0 is preferable, More preferably, it exists in the range of 4, O0 to 15.000.
    [66] As addition amount of the said epoxy group containing vinyl copolymer (B), the inside of the range of about 0.1 to about 10 weight% is preferable with respect to (A) component, More preferably, it exists in the range of 0.5 to 5 weight%. The epoxy group-containing vinyl copolymer (A) and the epoxy group-containing vinyl copolymer (B) are substantially incompatible within the range of the addition amount of the epoxy group-containing vinyl copolymer (B). It is preferable from a viewpoint. Substantially incompatible here means that the epoxy group-containing vinyl copolymer (A) and the epoxy group-containing vinyl copolymer (B) are mixed within the above range, heated to melt both, and then cooled to form a film. It is a case where turbidity appears in the film.
    [67] In order to prevent the said epoxy group containing vinyl copolymer (A) and an epoxy group containing vinyl copolymer (B) from becoming substantially compatible, the difference of SP value of an epoxy group containing vinyl copolymer (A) and an epoxy group containing vinyl copolymer (B) It is preferable to exist in the range of 0.5-4.0, More preferably, it is in the range of 1.0-4.0. Moreover, it is preferable that an epoxy group containing vinyl copolymer (B) has SP value lower than an epoxy group containing vinyl copolymer (A).
    [68] SP value here is a parameter which shows the polarity of resin, and is calculated | required by the following method.
    [69] 0.5 g of sample resin is added to a 100 ml Meyer flask, and 10 ml of tetrahydrofuran (THF) is added to dissolve the resin. Hexane was added dropwise using a 50 ml burette while the dissolved solution was maintained at a liquid temperature of 25 ° C., and the dropping amount (V h ) of the point (cloudy point) where turbidity occurred in the solution was obtained.
    [70] Next, the dropping amount (Vd) at the turbidity point when deionized water is used instead of hexane is obtained.
    [71] From V h , V d , the SP value δ of the resin is determined by SUH, CLARKE [J. Polym. Sci. A-1, Vo1.5, 1671-1681 (l967)] can be obtained as follows.
    [72] δ = [(V mh ) (1/2) δ mh + (V md ) (1/2) δ md ) / (V mh ) (1/2) + (V md ) (1/2) ]
    [73] From here,
    [74] V mh = (V h ㆍ V t ) / (Φ h ㆍ V t + Φ t ㆍ V h ),
    [75] V md = (V d ㆍ V t ) / (Φ d ㆍ V t + Φ t ㆍ V d ),
    [76] δ mh = Φ h ㆍ δ h + Φ t ㆍ δ t ,
    [77] δ md = Φ d ㆍ δ d + Φ t ㆍ δ t
    [78] Φ h , Φ d , Φ t ; Volume fraction of hexane, deionized water and THF at the turbidity point
    [79] (Φ h = V h / (V h +10), Φ d = / (V d +10))
    [80] δ h , δ d , δ t ; SP value of hexane, deionized water, THF
    [81] V h , V d , V t ; For molecules of hexane, deionized water and THF (ml / mol)
    [82] As polyhydric carboxylic acid (C), aliphatic or aromatic polyhydric carboxylic acids can be mainly used.
    [83] Representative examples of them include succinic acid, glutaric acid, adipic acid, fimer acid, sveric acid, azelaic acid, sebacic acid, brush phosphoric acid, dodecane diacid, eicosan diacid, tetraeisan diacid, Maleic acid, citraconic acid, itaconic acid or glutaconic acid;
    [84] Phthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid or cyclohexene-1,2-dicarboxylic acid: or an acid anhydride thereof and the like.
    [85] Moreover, the urethane modified compound obtained by making the polyhydric carboxylic acid or its anhydride mentioned above, and a polyisocyanate compound react can also be used. These polyhydric carboxylic acids (C) can also use 2 or more types together independently. Among these, an aliphatic dibasic acid is preferable at the point which is excellent in a coating film physical property and storage stability, and especially a dodecane diacid and its anhydride from a point which is excellent in a coating film physical property.
    [86] In the present invention, the compounding ratio of the above-mentioned epoxy group-containing polyfunctional vinyl copolymer (A) and (B) with the polyvalent carboxylic acid (C) is an epoxy group in the copolymer (A) and the copolymer (B), and a polyvalent The equivalent ratio of [(A) + (B)] / (C) of the carboxyl group in carboxylic acid (C) is preferable in the range of about 0.5 to about 1.5, More preferably, it is in the range of about 0.8 to about 1.2.
    [87] The powder coating of the present invention further includes various synthetic resins such as epoxy resins, polyester resins, urethane resins or polyamide resins, and the like.
    [88] Various conventional paint additives or pigments such as pigment dispersants, curing catalysts, flow regulators, gloss removers, antiblocking agents, ultraviolet absorbers, light stabilizers, benzoin, antistatic agents or antioxidants can be added and used as necessary. have.
    [89] Examples of such additives that can be used as ultraviolet absorbers, light stabilizers, or antioxidants include 2.4-dihydroxybenzophenone ("seesaw 100"), 2,2 ', 4,4'-tetrahydroxybenzo Phenone, 2-hydroxy-4-methoxybenzophenone (“seesaw moiety 101”), 2,2′-dihydroxy-4,4′-methoxybenzophenone or 2-hydroxy-4-methoxy- Various benzophenones such as 5-sulfobenzophenone;
    [90] 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole ("tinuvin 328"), 2- (2'-hydroxy-5'-methyl-phenyl) benzotriazole ( Various benzotriazoles such as "tinuvin P"), 2- [2-hydroxy-3.5-di (1,1-dimethylbenzyl) phenyl] -2H benzotriazole ("tinuvin 9O0"): phenylsalicyl Various salicylates such as the rate ("seesaw 201");
    [91] Various substituted acrylonitrile-based compounds such as ethyl-2-cyano-3.3'-diphenylacrylate ("seesaw part 501"); Various oxalic acid anhydrides such as 2-ethoxy-2'-ethyloxamic bisanilide ("tinuvin 312"); Various nickel complexes such as [2,2'-thiobis (4-tert-octylphenolate)]-2-ethylhexylamine-nickel (II) ("seesaw part 612NH");
    [92] Bis (1,2,2,6,6, -pentamethyl-4-piperidyl) sebacate ("tinuvin 292"), bis (2-2,6,6, -tetramethyl-4-piperi Dill) sebacate ("tinuvin 770"), 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid bis (1.2.2,6-pentamethyl- Various hindered amines such as 4-piperidyl) ("tinuvin 144");
    [93] 3,5-di-tert-butyl-4-hydroxytoluene ("BHT swanox"), tetrakis- [methylene- (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] ( And various phenolic compounds such as " lorganox 1010 "
    [94] Typical examples of those that can be used as a curing catalyst include phosphines such as triphenylphosphine, imidazoles such as 2-methylimidazole, ammonium salts such as tetrabutylammonium chloride, triphenylphosphonium bromide and the like. And tertiary amines such as phosphonium salts and methyl gicocoamines.
    [95] Examples of what can be used as a pigment include titanium oxide, iron group, chromium titanium yellow, various iron pigments such as yellow iron oxide and carbon black, phthalocyanine series such as phthalocyanine blue and phthalocyanine green, indalene blue, and dianthraqui Known such as anthraquinones such as noniled, quinacridones, lakereds, first yellows, azos such as disazo yellows and permanent reds, nitros such as naphthol yellows, nitrosos such as pigment green B and naphthol greens Various conventional pigments known for use, such as conventional organic pigments, calcium carbonate, barium sulfate, barium oxide, talc, silica, and also various conventional brightnesses such as aluminum flakes, mica and flakes ) Pigments and the like. As the polish remover, fumed silica may also be used.
    [96] As described above, the powder coating of the present invention is characterized by a particle diameter shape such as a significantly higher average circularity than the conventional powder coating, and exhibits excellent fluidity and coating workability based on the particle shape. Even when the film is thinned, excellent smoothness and finish appearance are achieved.
    [97] As a method for producing such powder coating, wet granulation methods such as suspension polymerization, freeze drying, and spray drying can be employed, and among these, spray powder drying can be used to produce the powder coating of the present invention. It is optimal.
    [98] For example, the epoxy group containing vinyl copolymer (A) which has a glass transition temperature of 40 degreeC or more, the epoxy group containing vinyl copolymer (B) which has a glass transition temperature of 0 degrees C or less, polyhydric carboxylic acid (C), and also a pigment as needed An organic solvent solution containing a coating film-forming component such as the following (hereinafter referred to as "powder coating raw material solution") does not substantially cause a curing reaction between the epoxy group-containing vinyl copolymers (A) and (B) and the polyhydric carboxylic acid (C). By spray drying at the temperature using the spray drying apparatus mentioned later, the powder coating of this invention can be obtained efficiently.
    [99] As the organic solvent used to adjust the powder coating raw material solution by this method, a solvent in which the epoxy group-containing vinyl copolymers (A) and (B) are dissolved but not the polyhydric carboxylic acid (C), and the epoxy group-containing vinyl copolymer are dissolved. A solvent which does not dissolve (A) and (B) but dissolves polyhydric carboxylic acid (C), or a solvent which dissolves any of epoxy group-containing vinyl copolymers (A) and (B) and polyhydric carboxylic acid (C) can be used. have. These may use only 1 type, or may use 2 or more types of solvent together, The solvent which melt | dissolves any of an epoxy-group-containing vinyl copolymer (A) and (B) and polyhydric carboxylic acid (C) among these is preferable. Here, in the case of resin in which epoxy group containing vinyl copolymer (A) and (B) were obtained by solution polymerization, the solvent used at the time of superposition | polymerization of epoxy group containing vinyl copolymer (A) and (B) is a part of organic solvent, or It can also be used as a whole.
    [100] This powder coating raw material solution is in a state where the epoxy group-containing vinyl copolymers (A) and (B) and the polyhydric carboxylic acid (C) are completely dissolved in an organic solvent at a temperature lower than the temperature when spraying, for example, at room temperature. It is preferable. When completely dissolved in this way, the epoxy group-containing vinyl copolymers (A) and (B) and the polyvalent carboxylic acid (C) are more uniformly mixed, compared with the mixing by melt kneading performed by a conventional production method, As a result, the powder coating which forms the coating film excellent in various coating film physical properties including a coating film external appearance can be obtained. Moreover, even if it is a solvent in which neither the epoxy group containing vinyl copolymer (A) and (B) and polyhydric carboxylic acid (C) melt | dissolve, it can be used as long as it does not impair the storage stability of powder coating raw material solution.
    [101] As an organic solvent which can be used to adjust this powder coating raw material solution, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, Alkyl alcohols such as isopentanol;
    [102] Methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether Same glycol ethers;
    [103] Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene; Mixed hydrocarbons containing aromatic hydrocarbons such as exon aromatic naphtha No. 2 (manufactured by Exxon, USA): aliphatic hydrocarbons such as n-pentane, n-hexane, n-octane; Mixed hydrocarbons containing aliphatic hydrocarbons such as isopa C, isopa E, Exol DSP10 / 140, Exol D30 (all of which are manufactured by Exxon Inc.), IP Solvent 1016 (manufactured by Idemitsu Chemical Co., Ltd.): cyclopentane, cyclohexane, Alicyclic hydrocarbons such as methylcyclohexane and ethylcyclohexane;
    [104] Ethers such as tetrahydrofuran, dioxane, diisopropyl ether, di-n-butyl ether; Ketones such as acetone, methyl ethyl ketone, methyl and isobutyl ketone; Esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, hexyl acetate, ethyl propionate, and butyl propionate. have. Moreover, a small amount of water can also be used together with the said organic solvent.
    [105] In the point of improving the dryness of the coating particle at the time of spray drying, it is preferable that the boiling point in normal pressure of the organic solvent occupies 65-10 weight% of the solvent.
    [106] Moreover, when polyhydric carboxylic acid (C) is an aliphatic dibasic acid, in order to improve solubility, a solvent contains at least 1 type of C4 or less alcohol, and the quantity of the C4 or less alcohol is a powder coating raw material. It is preferable that it is four times or more by weight ratio with respect to the aliphatic dibasic acid contained in a solution.
    [107] If necessary, the above-mentioned pigments, other resins, curing catalysts, additives and the like may be added to the powder coating raw material solution to dissolve or disperse and spray-dry.
    [108] After disperse | distributing the pigment as mentioned above in powder coating raw material solution, a coloring powder coating can be prepared by spray-drying. As a method of disperse | distributing a pigment in powder coating raw material solution, well-known conventional methods, such as a sand mill, can be used. Moreover, a coloring powder coating can also be manufactured by mixing a some coloring powder coating material solution, adjusting a color, preparing the coloring powder coating material solution which has the target color, and spray-drying.
    [109] Next, the spray drying apparatus will be described.
    [110] The thermosetting powder coating of the present invention can be obtained by spray drying the powder coating raw material solution adjusted as described above. The apparatus used for the spray drying may be one capable of removing the organic solvent from the sprayed powder coating raw material solution. For example, spray drying in which the sprayed powder coating raw material solution is brought into contact with a heat source gas to volatilize the organic solvent. Devices and the like can be used. In terms of volatilizing the organic solvent, the device is preferably explosion-proof. Moreover, it is preferable to provide a solvent collection | recovery apparatus from a viewpoint of keeping the vapor content of the solvent in the heat source gas used for drying the sprayed powder coating raw material solution low.
    [111] In the case of using a spray drying apparatus in which the sprayed powder coating raw material solution is contacted with a heat source gas to volatilize an organic solvent, the contact method of the powder coating raw material solution and the heat source gas is not particularly limited, and is commonly used Either a formula, countercurrent type, cocurrent / countercurrent mixed type may be sufficient.
    [112] Regarding the spraying method of the powder coating raw material solution, any of conventionally known ones, such as a rotating disk type, a two-fluid nozzle type, and a pressure nozzle type, can be used. As a factor for controlling the particle diameter when spraying, the rotational speed of the disk in the rotary disk type, the discharge speed from the nozzle in the two-fluid nozzle type, the mixing ratio of the compressed air and the raw material solution used in mixing with the raw material solution, and the pressure nozzle In the formula, there are discharge pressure and the like, and these values may be appropriately determined depending on the target particle diameter.
    [113] The feed rate of the raw material solution and the flow rate of the heat source gas may be appropriately determined according to the target particle diameter. However, if the feed rate of the raw material solution or the flow rate of the heat source gas changes during spray drying, the particle diameters and particle diameters of the resulting particles are changed. Since the value of distribution and non-volatile content also changes, it is preferable to keep it constant during spray drying.
    [114] Usually, the heat source gas containing the particle | grains obtained by spray drying is guide | induced to the classification apparatus represented by a cyclone, and particle | grains collection and classification are performed. In order to adjust the particle size distribution of the powder coating of the present invention, when a classification for removing coarse particles or fine particles is required, a commercially available general classifier may be used.
    [115] As a heat source gas, an inert gas is preferable. Among them, the use of nitrogen gas is preferable in terms of cost and the like. The temperature of the heat source gas is suitably in a temperature range in which the thermosetting resin and the curing agent of the powder coating raw material solution do not substantially cause a curing reaction, that is, a performance in which the performance of the powder coating obtained as a coating material is not substantially impaired even if some curing reaction occurs. You decide. Although there is no restriction | limiting in particular about the minimum of heat source gas temperature, In order to evaporate a solvent efficiently, 30 degreeC or more is preferable and it is more preferable to set it as 40 degreeC or more. Usually, the temperature of a heat source gas is suitably determined in 30-160 degreeC, More preferably, it is 40-130 degreeC.
    [116] What is necessary is just to adjust suitably according to the target particle diameter on the conditions which the flow rate of a heat source gas and the supply speed | rate of powder coating raw material solution will be 99 weight% or more of the non volatile matter of the obtained particle | grains. The pressure in the apparatus is not particularly limited even if it is normal pressure, reduced pressure or pressure.
    [117] In addition, what is necessary is just to determine the non volatile matter concentration of the powder coating raw material solution at the time of spray drying suitably according to the specification of the spray drying apparatus, and the conditions to spray-dry.
    [118] Moreover, in order to perform evaporation of a solvent more efficiently, you may preheat before powder-drying a powder coating raw material solution. The temperature to be preheated at that time is preferably 70 ° C. or lower in order to prevent gelation of the powder coating raw material solution, and is preferably spray dried as soon as possible after preheating.
    [119] The powder coating thus obtained can be used as it is as a powder coating, but may be further dried by another drying method such as vacuum drying if necessary. In that case, in order to prevent gelation of powder coating, it is preferable to perform secondary drying at the temperature of about 70 degreeC or less.
    [120] The thermosetting powder coating of the present invention is mainly applied to a wide range of applications such as automotive top coat, automotive middle coat, automotive parts, building materials, home appliances, and various metal products. can do.
    [121] As for the coating method, it is possible to apply a variety of well-known conventional methods such as electrostatic spraying method, triboelectric charging method, flow immersion, etc. to coat the substrate to be coated, and the resulting coating material is about 120 to about 250 ° C. The baking of the powder coating can be obtained by baking at the temperature of.
    [122] The powder coating of the present invention can be suitably used as a bottom coating or a top coat coating in a coating film forming method for forming a single layer or a multilayer coating on a coating object. In particular, since it has the outstanding smoothness, it can be used suitably as a top coat paint in the coating film formation method which coats a basecoat paint on a to-be-coated object, and coats a topcoat paint again on it. Moreover, it is more preferable that the basecoat paint is an aqueous coloring basecoat paint, and the topcoat paint is a transparent topcoat paint.
    [123] Here, the to-be-coated means the base material to which a coating material is apply | coated, Specifically, it is an uncoated metal material, such as an unpainted steel plate, an untreated or chemically processed aluminum base material, and is used for automobile bodies, two-wheeled vehicle bodies, etc. The base material used for road vehicles, the base material used for automobile parts, such as an aluminum wheel, the base material used for beverage cans, etc. are mentioned. Moreover, the base material used for road vehicles, such as a motor vehicle body in the state in which electrodeposition coating was performed is also included. In addition, substrates used in home appliances, vending machines, steel furniture, and the like, for example, electro galvanized steel sheets and hot dip galvanized steel sheets, and various building interior and exterior materials such as roof tiles, glass, doors, fences, and aluminum chassis. And the like.
    [124] These substrates may be processed into a shape according to the end use, and a multilayer coating film may be formed using the powder coating of the present invention as a form in which a PCM (precoat metal) coating method is applied, that is, a substantially flat plate-shaped substrate. After being formed, it may be bent into a predetermined shape according to the purpose, or may be a substrate used in a coating system that is completely sent to post-processing such as coil coating.
    [125] As described above, the thermosetting powder coating of the present invention is applied to various kinds of substrates as described above by conventional methods, and then bake-dried according to conventional methods, in particular for appearance, weather resistance and rubbing resistance. It is possible to provide a powder coating having excellent compatibility.
    [126] Example
    [127] Next, the present invention will be described in more detail by reference examples, examples and comparative examples, but the present invention is not limited to these examples. Hereinafter, unless otherwise indicated, "part" shall mean "part by weight".
    [128] Reference Example 1 [Preparation of Epoxy Group-Containing Vinyl Copolymer (A-1)]
    [129] 100 parts of xylene was placed in a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet, and the temperature was raised to 130 ° C.
    [130] Thereto, 30 parts of glycidyl methacrylate, 25 parts of n-butyl methacrylate, 30 parts of methyl methacrylate and 15 parts of styrene, and tert-butyl peroxy 2-ethylhexanoate 4 as a polymerization initiator The mixture consisting of parts was added dropwise over 5 hours.
    [131] The solution (A'-1) of the epoxy group containing vinyl copolymer (A-1) was obtained by hold | maintaining at the same temperature after completion | finish of dripping for 10 hours, and completing a polymerization reaction. Furthermore, the epoxy group containing vinyl copolymer (A-1) was obtained by hold | maintaining the obtained copolymer solution (A'-1) under 170 degreeC and the reduced pressure of about 20 Torr, and removing xylene. Table 1 shows the properties of the epoxy group-containing vinyl copolymer (A-1) and the solution (A'-1).
    [132] Reference Example 2 [Preparation of Epoxy Group-Containing Vinyl Copolymer (A-2)]
    [133] A solution (A'-2) of the target epoxy group-containing vinyl copolymer (A-2) was prepared in the same manner as in Reference Example 1 except that the mixture consisting of the monomer and the polymerization initiator used was changed as shown in Table 1. Got it. In addition, the epoxy solution-containing vinyl copolymer (A-2) was obtained by maintaining a copolymer solution (A'-2) under 170 degreeC and the reduced pressure of about 20 Torr, and removing xylene. The properties of the copolymer (A-2) and the solution (A'-2) are shown in Table 1.
    [134] TABLE 1
    [135] Reference Example 1Reference Example 2 A-1A-2 MonomerStyrene1515 Methyl methacrylate3525 n-butyl methacrylate520 Glycidyl methacrylate4540 Polymerization initiatortert-butylperoxy2-ethylhexanoate7.54.0 Properties of Copolymer (A)Glass transition temperature (℃)7060 Number average molecular weight2,3003,200 Epoxy equivalent weight345375 SP value10.3910.14 Copolymer solution (A ') property valueNonvolatile matter (%)51.551.0
    [136] [Glass transition temperature (° C)]
    [137] The numerical value which converted temperature (K) calculated by the following Fox formula into (degreeC).
    [138] 10O / Tg = W1 / Tg1 + W2 / Tg2 + W3 / Tg3 + W4 / Tg4
    [139] In formula, W1, W2 ... represents the mass fraction (mass%) of various components.
    [140] Where Tg1, Tg2 ... denote the glass transition temperature (K) of the homopolymers of the various components. Here, the glass transition temperature of the homopolymer was a value described in Polymer Handbook (Second Edition, J, Brandrup · E, H, Immergut).
    [141] [Number average molecular weight]
    [142] The number average molecular weight by molecular weight measurement in the gel permeation chromatography of the tetrahydrofuran soluble component.
    [143] [Epoxy equivalent]
    [144] Measurement value by hydrochloric acid-pyridine method.
    [145] (SP value)
    [146] A value obtained by the method described above in the "embodiment of the invention" herein.
    [147] Reference Example 3 [Preparation of Epoxy Group-Containing Vinyl Copolymer (B-1)]
    [148] In a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet, 100 parts of xylene was added and the temperature was raised to 120 ° C.
    [149] As shown in Table 2, the mixture which consists of a monomer and a polymerization initiator was dripped over 4 hours, respectively. After completion of the dropwise addition, the mixture was maintained at the same temperature for 10 hours, and the polymerization reaction was continued to complete the reaction to obtain a solution (B'-1) of the epoxy group-containing vinyl copolymer (B-1).
    [150] Furthermore, the epoxy group containing vinyl copolymer (B-1) was obtained by hold | maintaining the obtained copolymer solution (B'-1) under 170 degreeC and the reduced pressure of about 20 Torr, and removing xylene. Table 2 shows the properties of the epoxy group-containing vinyl copolymer (B-1) and the solution (B'-1).
    [151] Reference Example 4 [Preparation of Epoxy Group-Containing Vinyl Copolymer (B-2)]
    [152] Except having changed the mixture which consists of a monomer to be used and a polymerization initiator as shown in Table 2, it carried out similarly to the reference example 3, and obtained the solution (B'-2) of the target epoxy group containing vinyl copolymer (B-2). . Moreover, the epoxy group containing vinyl copolymer (B-2) was obtained by maintaining each copolymer solution (B'-2) under reduced pressure of about 20 Torr, and removing xylene. The properties of the copolymer (B-2) and the solution (B'-2) are shown in Table 2.
    [153] TABLE 2
    [154] Reference Example 3Reference Example 4 B-1B-2 MonomerMethyl methacrylate52-ethylhexyl acrylate Glycidyl methacrylate1530n-butyl methacrylate2530 2-ethylhexyl methacrylate15"Acryster SL" 40 Stearyl methacrylate40Polymerization initiatortert-butylperoxy2-ethylhexanoate0.20.7 Properties of Copolymer (A)Glass transition temperature (℃)-42-16 Number average molecular weight9,4006,700 Epoxy equivalent weight950480 SP value8.538.91 Copolymer solution (A ') property valueNonvolatile matter (%)50.049.8
    [155] Notice:
    [156] "Acryster SL": The brand name of the mixture of the methacrylic acid alkyl ester which has a C12 alkyl group which is a Mitsubishi Rayon product in a side chain, and the methacrylic acid alkyl ester which has a C13 alkyl group in a side chain.
    [157] Reference Example 5 [Preparation Example of Mixture (S-1) and (S-2) of Epoxy Group-Containing Vinyl Copolymer (A-1) and Epoxy Group-Containing Vinyl Copolymer (B-1)]
    [158] The epoxy group-containing vinyl aerials obtained in Reference Examples 2 and 4 in the same manner so that the solutions (A'-1) and (B'-1) of the epoxy group-containing vinyl copolymers obtained in Reference Examples 1 and 3 were 97 to 3 in solid content. The solution (A'-2) and (B'-2) of the copolymer were added to a container so as to have a solid content ratio of 95 to 5, stirred and mixed, kept under reduced pressure of about 20 Torr, and xylene was removed. The above mixtures (S-1) and (S-2) were obtained.
    [159] (Example 1)
    [160] The solution (A'-1) and (B'-1) of the epoxy group-containing vinyl copolymer were used so that the epoxy group-containing vinyl copolymers (A-1) and (B-1) had a composition as shown in Table 3. The powder coating raw material solution was adjusted by mixing and mixing the polyhydric carboxylic acid (C) and additive which were shown in Table 3 by the mixing | blending ratio as shown in this table. Using this powder coating raw material solution, a powder coating was produced by using a rotating disk type as a spraying method with an explosion-proof vertical dropping cocurrent spray drying apparatus equipped with a solvent recovery device. The rotational speed of the disk was 15.000 rpm, and nitrogen gas was used as the heat source gas, and the source solution and the heat source gas were brought into contact with each other in a vertically downward co-current fashion. The temperature of gas was set to 120 degreeC. Powder coating (X-1) of the present invention by spraying the powder coating raw material solution preheated to 60 ° C. into the spray drying apparatus at a feed rate of 0.5 kg / hr, and collecting the particles of the powder coating dried in the apparatus with a cyclone. Got.
    [161] The average particle diameter and circularity distribution of the obtained powder coating material (X-1) were calculated | required with the flow type particulate-form analyzer "FPIA-10O0" (made by the Toyo Denko Co., Ltd. product). The obtained circularity distribution map is shown in FIG.
    [162] From the results, the average particle diameter of the particles is 15 µm, the average circularity is 0.97, and the circularity of the particles having the maximum number frequency in the circularity distribution is 0.99 to 1.00. It is found that the particles of this powder coating are close to the spherical particles, since the ones are much higher than those of other circularities.
    [163] [Circular drawing]
    [164] One of the particle shape indexes showing the unevenness of the particle surface, which is expressed by the following equation.
    [165] Circularity = (circle of circle with the same area as particle projection area) / (perimeter of particle projection image)
    [166] [Circularity of Particles with Maximum Number of Frequencies in Circularity Distribution]
    [167] The circularity of the particle having the maximum number frequency in the circularity distribution means that the circularity distribution obtained by the above measurement is divided into 0.40 to 1.00 for the circularity of the particles, and the frequency of the number in each section (a circularity of 0.01 width) is obtained. Is the circularity of the section which becomes the maximum.
    [168] This powder coating (X-1) was coated on a 0.8 mm thick abrasive steel plate subjected to zinc phosphate treatment using an electrostatic spray coating machine for powder coating, and then baked at 150 ° C. for 30 minutes to obtain a test plate having a cured coating film. The smoothness, gloss, scratch resistance and storage stability of the powder coating were evaluated. Table 4 shows their evaluation judgment results and evaluation results of coating workability of the paint.
    [169] (Example 2)
    [170] Using solutions (A'-2) and (B'-2) of the epoxy group-containing vinyl copolymer, the epoxy group-containing vinyl copolymers (A-2) and (B-2) were made to have a composition as shown in Table 3. The powder coating material was prepared in the same manner as in Example 1 except that the powder coating raw material solution was adjusted by mixing and mixing the polyhydric carboxylic acid (C), the additive, and the pigment shown in Table 3 in the mixing ratio as shown in this table. 2) was prepared.
    [171] The average particle diameter of the obtained powder coating material (X-2) was 35 micrometers, the average circularity was 0.95, and the circularity of the particle which has the largest number frequency in the circularity distribution was 0.99-1.00.
    [172] This powder coating (X-2) was coated and evaluated in the same manner as in Example 1. The results are shown in Table 4.
    [173] (Comparative Example 1)
    [174] Each component shown in Table 3 was mix | blended using the mixture (S-1) of an epoxy group containing vinyl copolymer (A-1) and an epoxy group containing vinyl copolymer (B-1) as a thermosetting resin component obtained by the reference example 5, Powder coating (Z-1) was produced by melt kneading. The average particle diameter and circularity distribution of the obtained powder coating were obtained as in Example 1. The obtained circularity distribution map is shown in FIG. The average particle diameter of the powder coating material (Z-1) was 14 micrometers, and the circularity of the particle which has the largest number frequency in the average circularity 0.88 and circularity distribution was 0.93-0.94.
    [175] From Fig. 2, it can be seen that a large number of particles of the powder coating have various circularities.
    [176] This powder coating (Z-1) was coated and evaluated in the same manner as in Example 1. The results are shown in Table 4.
    [177] (Comparative Example 2)
    [178] Each component shown in Table 3 was mix | blended using the mixture (S-2) of an epoxy-group-containing vinyl copolymer (A-2) and an epoxy-group-containing vinyl copolymer (B-2) like the comparative example 1, and the melt-kneading method By powder coating (Z-2). The average particle diameter of powder coating material (Z-2) was 36 micrometers, and the circularity of the particle which has the largest number frequency in the average circularity of 0.86 and circularity distribution was 0.93-0.94.
    [179] This powder coating (Z-2) was coated and evaluated in the same manner as in Example 1. The results are shown in Table 4.
    [180] (Comparative Example 3)
    [181] Each component shown in Table 3 was mix | blended using the epoxy group containing vinyl copolymer (A-1) obtained by the reference example 1, and the powder coating material (Z-3) was produced by the melt kneading method. The average particle diameter of powder coating material (Z-3) was 26 micrometers, and the circularity of the particle | grains which have the largest number frequency in the average circularity 0.91 and circularity distribution was 0, 92-0.93.
    [182] This powder coating (Z-3) was coated and evaluated in the same manner as in Example 1. The results are shown in Table 4.
    [183] (Comparative Example 4)
    [184] Using the epoxy group-containing vinyl copolymer solution (A'-1) obtained in Reference Example 1, the components shown in Table 3 were blended, and powder coating (Z) was carried out in the same manner as in Example 1 except that the powder coating raw material solution was adjusted. -4) was prepared.
    [185] The average particle diameter of the obtained powder coating material (Z-4) was 35 micrometers, the average circularity was 0.99, and the circularity of the particle which has the largest number frequency in circularity distribution was 0.99-1.00.
    [186] This powder coating (Z-4) was applied and evaluated in the same manner as in Example 1. The results are shown in Table 4.
    [187] TABLE 3
    [188] Example 1Example 2Comparative Example 1Comparative Example 2Comparative Example 3Comparative Example 4 Powder Coating NameX-1X-2Z-1Z-2Z-3Z-4 Epoxy group-containing vinyl copolymer (A) and epoxy group-containing vinyl copolymer (B)A-197 100100 A-2 95 B-13B-2 5 Solid cargoS-1 100 Solid cargoS-2 100 Polyhydric carboxylic acid (C)Dodecan 2-mountain292629262929 additiveBenzoin0.50.50.50.50.50.5 "Modaflop P2000" 1.0 1.0 "KP322"0.2 0.2 0.20.2 Pigment"CR-90" 56 56
    [189] Notice:
    [190] "Modaflo P2000": The brand name of the acrylic type leveling agent manufactured by Monsanto, USA.
    [191] "KP322": The brand name of the silicone type leveling agent made from Shinsei Chemical Co., Ltd ..
    [192] "CR-90": Rutile titanium oxide "Tipe CR-90" from Stone.
    [193] TABLE 4
    [194] Example 1Example 2Comparative Example 1Comparative Example 2Comparative Example 3Comparative Example 4 Powder Coating NameX1X-2Z-1Z-2Z-3Z-4 Film thickness (㎛)304031413535 Smoothness554324 Coating glossiness (60 degrees gloss)979691899293 Coating gloss (20 degrees gloss)929081807985 Scratch resistance5544 One2 Storage stability△○××△○ Painting workability○◎×××○
    [195] (Paint and coating film physical property evaluation judgment method)
    [196] Film thickness: measured using an electronic film thickness meter.
    [197] Smoothness: Five levels of evaluation judgments were made by visual inspection.
    [198] Rating "5": for a very smooth smooth painted surface.
    [199] Evaluation "4": if there is a small round.
    [200] Evaluation "3": When there is a big round.
    [201] Evaluation "2": when there is a large round, and a lot of fine contamination surface is confirmed.
    [202] Evaluation "1": When there is a large round, the fine contaminated surface is remarkable, and the coating film appearance is remarkably damaged.
    [203] Coating glossiness: It measured with the mirror surface glossiness of JIS-K5400.
    [204] Scratch Resistance: The cleansing resistance was measured. In the measurement method, a 5% cleanser water dispersion was immersed in a flannel cloth, subjected to 50 round trip rubbing under a load of 500 g, and measured 20 degrees gloss (20 degrees mirror surface reflectance:%) before and after rubbing. The gloss retention (%) in rubbing obtained from this was evaluated in five stages.
    [205] Evaluation "5": gloss retention 90% or more.
    [206] Evaluation "4": gloss retention 80% or more less than 90%
    [207] Evaluation "3": gloss retention 65% or more less than 80%
    [208] Evaluation "2": gloss retention 50% or more less than 65%
    [209] Rating "1": gloss retention less than 50%
    [210] Storage stability: The powder coating was stored at 35 degreeC for 1 month, and the fluidity | liquidity of the powder coating was evaluated.
    [211] Evaluation 0: There is no lump and fluidity is very good.
    [212] Evaluation △: A little lump is confirmed, but is solved.
    [213] Evaluate x: Unsolved chunks are identified.
    [214] Coating workability: After coating powder coating for 1 hour continuously by a hose from a fluidized bed via an injector, the deposit state of the powder coating in an injector and a hose was visually determined.
    [215] Evaluation ◎: Powder coating was not deposited at all.
    [216] Evaluation 0: Powder coating hardly deposited.
    [217] Evaluation x: Powder coating deposited and the injector or the hose was almost closed.
    [218] The powder coating according to the present invention is excellent in fluidity and coating workability, and excellent in smoothness and finish appearance even when the resulting coating film is a thin film, and also excellent in scratch resistance.
    权利要求:
    Claims (4)
    [1" claim-type="Currently amended] As a coating film formation component, the epoxy group containing vinyl copolymer (A) which has a glass transition temperature of 40 degreeC or more, the epoxy group containing vinyl copolymer (B) which has a glass transition temperature of O degrees C or less, and polyhydric carboxylic acid (C) It is composed of particles containing, the average particle diameter of the whole particle is 5 to 50㎛, the average circularity of the particles is 0.90 or more, and the maximum number frequency in the circularity distribution Thermosetting powder coating having a circularity of 0.98 to 1.00 of the particles having a.
    [2" claim-type="Currently amended] The method of claim 1,
    The epoxy group-containing vinyl copolymer (B) has a lower SP value than the epoxy group-containing vinyl copolymer (A), and the difference in the SP value between the epoxy group-containing vinyl copolymer (A) and the epoxy group-containing vinyl copolymer (B) is 0.5. Thermosetting powder coating of -4.0.
    [3" claim-type="Currently amended] The coating material which formed the coating film by thermosetting the powder coating of Claim 1 or 2 on the to-be-painted object.
    [4" claim-type="Currently amended] A powder coating raw material solution comprising an epoxy group-containing vinyl copolymer (A) having a glass transition temperature of 40 ° C. or higher, an epoxy group-containing vinyl copolymer (B) having a glass transition temperature of 0 ° C. or lower, and a polyhydric carboxylic acid (C). A method of producing a thermosetting powder coating by spray drying to obtain a thermosetting powder coating having an average circularity of 0.90 or more, a circularity of 0.98 to 1, and an average particle size of 5 to 50 µm, with a maximum frequency of circularity distribution. .
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    同族专利:
    公开号 | 公开日
    JP2002371227A|2002-12-26|
    EP1266938B1|2007-01-24|
    JP4910248B2|2012-04-04|
    EP1266938A2|2002-12-18|
    DE60217763D1|2007-03-15|
    US20030026993A1|2003-02-06|
    US6649267B2|2003-11-18|
    EP1266938A3|2004-01-02|
    DE60217763T2|2007-11-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2001-06-15|Priority to JPJP-P-2001-00181533
    2001-06-15|Priority to JP2001181533A
    2002-05-31|Application filed by 다이니혼 잉키 가가쿠 고교 가부시키가이샤, 가부시키가이샤 리퀴드 가스
    2002-12-31|Publication of KR20020096881A
    优先权:
    申请号 | 申请日 | 专利标题
    JPJP-P-2001-00181533|2001-06-15|
    JP2001181533A|JP4910248B2|2001-06-15|2001-06-15|Thermosetting powder coating and painted products|
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