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    • 专利摘要:
    dry cellulose filament flakes, dry cellulose filament film, and method for preparing a dry cellulose filament film The present invention relates to dry cellulose filaments particularly those which are redispersible in water. dry cellulose filaments comprise at least 50% by weight of the filaments having a filament length of up to 350 (mi)m; and a diameter between 100 and 500 nm, where the filaments are redispersible in water. also described herein is a film of dry cellulose filaments comprising the described filaments, wherein the film is water-dispersible. also described is a method for preparing a dry film of cellulose filaments which includes providing a liquid suspension of the described cellulose filaments and retaining the filaments in the forming section of a paper or tissue making machine or in a paper making machine or modified fabric. film can be operatively converted to powders or flakes for shipping, storage or subsequent uses. the filaments, film, or powders or flakes and the method are in a preferred embodiment free from additives and filament derivatization.
    公开号:BR112015010341B1
    申请号:R112015010341-3
    申请日:2013-11-07
    公开日:2021-08-24
    发明作者:Gilles Marcel Dorris；Yuxia Ben；Thomas Qiuxiong Hu；Patrick Neault
    申请人:Fpinnovations；
    IPC主号:
    专利说明:

    FIELD OF THE INVENTION
    [001] The present invention relates to dry cellulose filaments and particularly those that are redispersible in water. FUNDAMENTALS OF THE INVENTION
    [002] Cellulose filaments (CF) previously referred to as cellulose nanofilaments (CNF) are known to have many properties of interest, one of which is the increase in the wet and dry strength properties of paper when used as an additive in production of these. They are produced by refining wood and plant fibers at a high to very high level of specific energy using consistency refiners (Hua, X., et al. High Aspect Ratio Cellulose Nanofilaments and Method for their Production. PCT/CA2012/000060 ; WO 2012/097446 A1, 2012). They have superior reinforcing capacity over cellulose microfibrils or nanofibrils, such as microfibrillated cellulose (MFC) or nanofibrillated cellulose (NFC) prepared using other methods for mechanical fibrillation of wood pulp fibers, due to their long sizes and higher ratio of appearance as a result of its unique production process that minimizes fiber shear.
    [003] The production of cellulose filaments occurs in suspension with water at a consistency of up to 60%. Consistency is the percentage by weight of a cellulose material in a mixture of the cellulose material and water. A serious disadvantage of using cellulose filaments is the difficulty of preparing dry cellulose filaments without decreasing their dispersibility in aqueous media and/or their strengthening capacity. This difficulty is similar to that of drying other cellulose microfibrils or nanofibrils or even pulp fibers by conventional means and is due to the so-called keratinization. Keratinization is attributed to many factors including: the formation of irreversible hydrogen bonds (H bridges) and/or the formation of lactone bridges (Fernandes Diniz, et al., “Hornization—its origin and interpretation in wood pulps” Wood Sci Technol, Vol. 37, 2004, pp. 489-494). Keratinization produces a dry cellulose filament material that cannot be redispersed in water, an aqueous solution, or an aqueous suspension, such as a pulp or paper suspension, when dry cellulose filaments are mixed with wood pulps in a pulper or mixing tray for use as a paper strength additive.
    [004] To avoid the disadvantage of irreversible keratinization that produces non-dispersible microfibrillated cellulose (MFC) or nanofibrillated cellulose (NFC) two approaches have been tried: 1) processing of MFC with additives or 2) derivatization of MFC or NFC.
    [005] Each of these approaches has its drawbacks. As the first approach to reducing keratinization, MFCs are dried with additives that block H-bridge formation and help prevent H-bridge and lactone-bridge formation (Herrick, FW, US 4,481,076; Lowys, M. -P. et al, "Rheological Characterization of Cellulosic Microfibril Suspension. Role of Polymeric Additives," Food Hydrocolloids, Vol. 15, 2001, pp. 25-32; and Cantiani, R. et al. US 6,306,207 B2). These additives include: sucrose, glycerin, ethylene glycol, dextrin or carboxymethyl cellulose. Here the disadvantage is the large amount of additives required, in some cases more than 15% by weight are used.
    [006] The second approach to reduce keratinization to MFC or NFC during drying is to derivatize microfibrillated or nanofibrillated cellulose with the introduction of various groups including carboxyl groups (Eyholzer, C. et al, “Preparation and Characterization of Water-Redispersible Cellulose nanofibrillated in Powder Form”, Cellulose, Vol. 17, No. 1, 2010, pp. 19-30; Cash, MJ et al. Derivatized Microfibrillar Polisaccharide US 6,602,994 B1). However, derivatization requires the use of large amounts of the reagent, eg 5.81 g of monochloroacetic acid (MCA) (7.26 g of 80% MCA) per 36 g of MFC in an isopropanol and aqueous solution under atmosphere of nitrogen. It has been established that MFC derivatized with MCA or other molecules can be redispersed in water after drying. SUMMARY
    [007] Prior to the present invention, no drying and water redispersible filaments of substantially fibrillated cellulose materials were reported. In the present invention, drying and water-redispersible fibrillated cellulose, cellulose filaments are produced free from chemical additives and free from derivatization, such as, for example, the carboxymethylated fibrillated cellulose materials.
    [008] According to one aspect of the present invention, there is provided a dry cellulose filament comprising: at least 50% by weight of the filaments having a filament length of up to 350 µm; and a diameter between 100 and 500 nm, where the filaments are redispersible in water.
    [009] According to yet another aspect of the present invention, the filaments described herein are provided, wherein at least 75% and more preferably 90% by weight of the filaments comprising a filament length of up to 350 µm; and a diameter between 100 and 500 nm.
    [0010] According to one aspect of the present invention there are provided the filaments described herein which are free of additives.
    [0011] According to another aspect of the present invention, the filaments described herein are provided which are free from derivatization.
    [0012] According to yet another aspect of the present invention, the filaments described herein are provided wherein the length of the filaments is between 300 and 350 µm.
    [0013] According to yet another aspect of the present invention, the filaments described herein are provided, wherein the filaments are at least 80% by weight solids.
    [0014] According to yet another aspect of the present invention, the filaments described herein are provided wherein the filaments are at least 80% and preferably 95% solids by weight.
    [0015] According to another aspect of the present invention, there is provided a film of dry cellulose filaments comprising: at least 50% by weight of the filaments with a filament length of up to 350 µm and a diameter between 100 and 500 nm, in that the film is water dispersible.
    [0016] According to a still further aspect of the present invention, there is provided the film described herein wherein at least 75% and more preferably 90% by weight of the filaments comprise a filament length of up to 350 µm; and a diameter between 100 and 500 nm.
    [0017] According to a further aspect of the present invention, there is provided the film described herein, wherein the film has a thickness range of 10 to 300 µm.
    [0018] According to a still further aspect of the present invention, there is provided the film described herein, wherein filaments are free from at least one of additives and derivatization.
    [0019] According to a still further aspect of the present invention, there is provided the film described herein, wherein the lengths of the filaments are between 300 and 350 µm.
    [0020] According to a still further aspect of the present invention, there is provided the film described herein, wherein the filaments are at least 80% by weight solids.
    [0021] According to an embodiment of the present invention, the film described herein is provided, wherein the filaments are at least 95% solids by weight.
    [0022] According to yet another aspect of the present invention there is provided a method for preparing a dry film of cellulose filaments comprising: providing a liquid suspension of the cellulose filaments wherein at least 50% by weight of the filaments have a length of filament up to 350 µm; and a filament diameter between 100 and 500 nm, and remaining filaments in a forming section of a papermaking machine. In a preferred embodiment the papermaking machine is a Standard Sheet Machine with a mesh selection of 150 to 400.
    [0023] According to yet another embodiment of the present invention the method described herein is provided, wherein at least 75% and more preferably 90% by weight of the filaments comprise a filament length of up to 350 µm; and a diameter between 100 and 500 nm.
    [0024] According to another embodiment of the present invention there is provided the method described herein, further comprising pressing the film in a press section of the machine to produce a pressed film.
    [0025] According to yet another embodiment of the present invention the method described herein is provided, further comprising drying the pressed film in at least one dryer section of the machine to produce the dry film.
    [0026] According to yet another embodiment of the present invention, the method described herein is provided, in which the film produced is redispersible in water.
    [0027] According to yet another embodiment of the present invention, the method described herein is provided, wherein the film produced has a thickness range of 200 to 300 Mm or less.
    [0028] According to a further embodiment of the present invention there is provided the method described herein, wherein the film is at least 80% solids by weight.
    [0029] According to still a further embodiment of the present invention the method described herein is provided, wherein the film is at least 95% solids by weight.
    [0030] According to yet a further embodiment of the present invention, the method described herein is provided, wherein the lengths of the filaments are between 300 and 350 µm.
    [0031] According to still a further embodiment of the present invention there is provided dry powders or flakes, water-redispersible of the filaments made from the film of the dry filaments, water-redispersible using mechanical devices that are capable of reducing the film size of the dry filaments , redispersible in water.
    [0032] According to still a further embodiment of the present invention, the method described herein is provided, wherein the papermaking machine operates at a speed of 500 to 1,500 m/min, preferably 750 to 1,200 m/min. BRIEF DESCRIPTION OF THE DRAWINGS
    [0033] Reference will now be made to the attached drawings, which show, by way of illustration, a particular embodiment of the present invention and in which: figure 1 a is a light microscopy image of representative cellulose filaments (CF) with, by visual inspection and estimation, at least 80% by weight of filaments having lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm produced by high-consistency, multi-pass refining of soft wood kraft pulp bleached according to with an embodiment of the present invention; Figure 2b is a scanning electron microscopy image of the representative cellulose filaments (CF) of Figure 1a; Figure 3 is a roll of dry, water-redispersible films of cellulose filaments (CF) ) produced on a pilot paper machine according to an embodiment of the present invention; Figure 4 illustrates five dispersions/suspensions where a/ is a comparative example of a CF never dried, dispersed in the laboratory (1); b/ is a dry CF in PM, redispersed in laboratory (1) that reflects various embodiments of the present invention; c/ are comparative examples of conventional drying where c/ is an air-dried CF, redispersed in the laboratory (2); d/ is a drum-dried CF, re-dispersed in the laboratory (2); and el is a fast dry CF, redispersed in the laboratory (2). DETAILED DESCRIPTION OF PARTICULAR MODALITIES
    [0034] In many potential applications dry fibrillated cellulose materials are required. Dry fibrillated pulp materials have a longer shelf life and reduce the cost of shipping materials from a production plant to an end-user location.
    [0035] Although several methods for dehydrating/drying fibrillated cellulose materials have been reported, no method for producing dry, water-redispersible fibrillated cellulose materials without the use of chemical additives or chemical modification of the materials has been described. Furthermore, no method for the continuous production of dry, water-redispersible fibrillated cellulose materials in a machine commonly used to make paper, fabric or cardboard has ever been reported.
    [0036] Cellulose nanofilaments (CNF), defined herein and referred to as cellulose filaments (CF), have in a preferred embodiment lengths of up to 300 to 350 μm and diameters of approximately 100 to 500 nm. CFs are produced by high-consistency, multi-pass refining of wood or plant fibers such as a bleached softwood kraft pulp as described in VVO2012/097446 A1 incorporated herein by reference. CFs are structurally very different from other cellulose fibrils such as microfibrillated cellulose (MFC) or nanofibrillated cellulose (NFC) prepared using other methods for mechanically disintegrating wood pulp fibers in which they are at least 50%, preferably 75 %, and more preferably 90% by weight of the filaments of the fibrillated cellulose material have a filament length of up to 300 to 350 µm and diameters of approximately 100 to 500 nm. MFC-fibrillated cellulose material typically has lengths of less than 100 µm, while NFC-fibrillated cellulose material typically has lengths of less than 1 µm. However, those skilled in the production of fibrillated cellulose materials should realize that CFs, like other fibrillated cellulose materials produced using mechanical means, are not a homogeneous material with a single dimension value. CF in a preferred embodiment having lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm defined herein refers to a fibrillated cellulose material produced by high-consistency, multi-pass refining of wood or plant fibers and with not less than 50% by weight of its fibrillated material having lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm. The precise percentage of fibrillated cellulose material having lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm depends on the total energy input, the number of refining passes, the refining intensity and other operating conditions of the refiner.
    [0037] According to one aspect of the present invention, there are provided dry cellulose filament flakes comprising at least 50% by weight of filaments having a filament length of up to 350 µm; and a diameter of between 100 and 500 nm, where the filaments are additive-free, derivatized, and redispersible in water.
    [0038] According to another aspect of the present invention, there is provided a dry cellulose filament film comprising at least 50% by weight of the filaments having; a filament length of up to 350 µm and a diameter of between 100 and 500 nm, where the film is redispersible in water, where the filaments are free from additives and derivatization.
    [0039] According to yet another aspect of the present invention, there is provided a method for preparing a dry film of cellulose filaments comprising: providing a liquid suspension of the cellulose filaments produced by high consistency multi-pass refining of plant fibers or wood, wherein at least 50% by weight of the filaments comprises a filament length of up to 350 µm; and a filament diameter of between 100 and 500 nm, and retaining more than 90% of the filaments in a forming section of a papermaking machine, where the filaments are free from additives and derivatization.
    [0040] These same cellulose filaments (CF) with lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm by multi-pass refining, of high consistency of wood and plant fibers, when dried using common drying methods , such as drum drying or air drying, are not completely redispersible in water and their reinforcing power is much lower than never dried CF. In a preferred embodiment the lengths of the CFs are 300 to 350 µm.
    [0041] The term "dry" as used herein in reference to the filaments described herein refers to a solid content of the cellulose filaments being not less than 80% by weight solids or a moisture content of not more than 20 % by weight. In a particularly preferred embodiment the solids content of the cellulose filament is not less than 90% by weight solids or a moisture content of not more than 10% by weight. The term "water-redispersible" as used herein refers to the ability of dry cellulose filaments to form a stable aqueous dispersion upon mechanical agitation in an aqueous medium at room or elevated temperature. This dispersion is free of materials such as quaternized cellulose precipitates that cannot be redispersed.
    [0042] The expressions "strength and/or strength properties similar to" are defined herein as comparative expressions indicating that not less than 80% of said CF strength and/or strength properties of the present invention are obtained on paper when compared to the same amount of CF never dried.
    [0043] The term "never dry" is defined herein to describe cellulose filaments (CF) that were never dried and remained in a wet stage with up to 60% solids by weight after their production of wood or plant fibers.
    [0044] The present invention first describes that dry cellulose filaments (CF) made to have and with lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm by multi-pass refining, of high consistency of wood fibers and plant can be retained when its diluted suspension is filtered through a 150 to 400 mesh sieve in a Standard Sheet Machine used to prepare slides in the laboratory or through the moving screen of a machine commonly used to make paper, fabric or cardboard.
    [0045] Also, unexpectedly, it was found that such cellulose filaments, when forming a very thin net, sheet or film on a moving screen of a machine commonly used to make paper, fabric or cardboard, and followed by pressing and drying in the press and dryer section of the machine respectively, are readily redispersible in aqueous media upon gentle mechanical agitation, and this without the use of additives to prevent keratinization. Furthermore, the cellulose filaments (CF) of the aqueous dispersion of dry, water-redispersible CF films have strengthening power similar to that of never-dried CF. Furthermore, new films made from the aqueous dispersion of dry, water-redispersible CF films have similar strength properties to films made from never-dried CF and are free of additives. It should be noted that air drying, rapid drying, spray drying, rotary air drying (ie, conventional methods) of drying mass material all reduce the quality of the CF produced by high consistency refining described herein. Dry, water-redispersible CF films can also be optionally converted to dry, water-redispersible CF powders or flakes for shipping, storage or subsequent uses.
    [0046] The term "film" as used herein is synonymous with the word "blade" and is understood as a layer or complex of CF membrane having an interconnected structure or arrangement of filaments or fibrils and formed by the method of the present invention . The film defined herein has a thickness range of 200 to 300 µm or less and preferably 100 to 125 µm or less, above all preferably 10 to 50 µm. The film width is set by the processing machine and can be up to several meters wide.
    [0047] The term "additive-free" is used here to describe CFs that have not been treated with additives to reduce keratinization. Additives that are used with other cellulose fibril films include: sucrose, glycerin, ethylene glycol, dextrin or carboxymethyl cellulose. The CFs of the present invention are free from the additives listed above.
    [0048] The term "powder or flakes" is used here to describe a shape that has all three dimensions from 0.01 mm to 2.0 cm, and more preferably from 0.01 mm to 1.0 cm. The precise dimensions of the powders or flakes are established by the mechanical device and the operating conditions of the devices used to reduce the film size of the dry, water-redispersible cellulose filaments.
    [0049] According to one aspect of the present invention dry, water-redispersible films of cellulose filaments (CF) are produced in a conventional or modified paper, fabric or cardboard machine by forming thin screens in the forming section of the machine, followed by pressing and drying in the press and dryer section of the machine. The paper machine has a forming fabric which is a three-dimensional woven fabric with interconnected pores typically 100-200 microns. These large pores allow for quick water drainage. All previous fibrillated products would pass through the pores with minimal retention. If even a tighter pore structure is used with these earlier known products, drainage could be such that the machine would have to run at 10 to 50 m/min, while running at: 750 m/min or more; preferably 1500 m/min and more preferably 1200 m/min. The ability of CF to be filtered in a paper machine indirectly grounds that the filaments of the present invention are different in length from MFC and NFC described above. The cellulose (CF) filaments of the present invention are up to 300 to 350 µm in length and approximately 100 to 500 nm in diameter and are made from high-consistency, multi-pass refining of wood and plant fibers. However, it is understood that the ideal pore size of the forming fabric for the production of dry, water-redispersible CF films depends on the precise percentage of the filaments having lengths of up to 300 to 350 μm and diameters of approximately 100 to 500 nm in the CF which, in turn, depends on the total energy input, number of refining passes, refining intensity and other operating conditions of the refiner used to produce the CF.
    [0050] According to another aspect of the present invention dry, water-redispersible films of cellulose filaments (CF) of the present invention are used for the storage and/or transport of the CF material.
    [0051] According to yet another aspect of the present invention the dry, water-redispersible films of cellulose filaments (CF) are converted to dry, water-redispersible powders or flakes of cellulose filaments for transport, storage or subsequent use of the CF material.
    [0052] According to yet another aspect of the present invention dry, water-redispersible films of cellulose filaments (CF) or dry, water-redispersible powders or flakes of cellulose filaments (CF) of the present invention are used, by redispersion in an aqueous medium, as an additive to reinforce cellulose fiber products such as paper, fabric and cardboard.
    [0053] The dry, water-redispersible films of cellulose filaments (CF) or the dry, water-redispersible powders or flakes of cellulose filaments (CF) of the present invention can also be used as strong and recyclable films for the manufacture of composites and for packaging or other applications. They can also be used, upon redispersion in an aqueous medium, as an additive to reinforce other consumer or industrial products.
    [0054] The dryness (solid content), the basis weight, and the first retention of the passage of redispersible films in water depends, among others, on the source and total energy used to manufacture the cellulose filaments (CF), on the speed of the fabric, paper or cardboard machine and machine configuration and operating parameters such as the number of vacuum box applied, head box consistency and flow rate, and the pore size of the forming fabric. CF is manufactured to have at least 50% by weight of its material fibrillated with lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm by high consistency (20 to 65% by weight) multi-pass refining of the wood and plant fibers with a total energy input of preferably 2,000 to 20,000 kvVh/t, more preferably 5,000 to 20,000 kWh/t, and most preferably 5,000 to 12,000 kWh/t, as described in the previous patent application PCT/CA2012/ 000060; WO 2012/097446 A1. The machine is operated in such a way as to enable the production of said CF films with a solid content of preferably 70 to 95% and more preferably 75 to 95% and above all preferably 80 to 95%; a basis weight of preferably 5 to 120 g/m2, more preferably 10 to 100 g/m2 and above all preferably 10 to 80 g/m2. Optionally, retention and drainage of chemical auxiliaries can be mixed with the CF in the headbox of the paper, fabric or paperboard machine to increase the first pass retention and/or the drainage rate of said dry, water-redispersible CF films.
    [0055] Virtually all solid material is filterable as long as the pore size of the filter media is small enough to retain the material. However, as pore size decreases, resistance to flow increases and thus drainage decreases. The present inventors have discovered that a quas-nano-in-water material is filterable at high speeds using high pressure drop conditions (ie, no need for high pressure and vacuum). A filtration speed of 750 m/min, 1000 m/min and more data from 100 to 500 nm in diameter on a relatively open tissue is surprising.
    [0056] “Consistency” is defined herein as the percentage by weight of wood and plant fibers or cellulose filaments (CF) in a mixture of water and wood and plant fibers or cellulose filaments (CF).
    [0057] Basis weight is defined here as the weight in grams (g) of the cellulose filament films (CF) or pulp fiber sheets and CF per square meter (m2) of said films or sheets.
    [0058] A weight that is dry based (od) in the present invention refers to the weight that excludes the weight of water. For a wet material such as CF it is the water free weight of the material which is calculated from its consistency.
    [0059] Referring now to the drawings, Figure 1 shows the electron microscopy image of representative cellulose filament (CF) scans with lengths of up to 300 to 350 μm and diameters of approximately 100 to 500 nm made by refining multi-pass, high consistency of a bleached softwood kraft pulp.
    [0060] The final CF film product of the machine has very little to no porosity.
    [0061] Furthermore, because the CF film of the present invention closes quickly during forming on the machine, drainage quickly drops as the film consolidates and its pore system is sealed. In this way, the film is better kept moving quickly in the machine and with a thin thickness. The film thickness is preferably 10 to 50 µm and not more than 300 µm.
    [0062] The present invention is illustrated, but without limitation, by the following examples. General procedure A: Production of dry, water-redispersible CF films in a pilot paper machine
    [0063] Dry, water-redispersible CF films were produced on FPInnovations pilot paper machine whose configuration can be adapted to produce medium to high basis weight printing and writing grades as well as fabric and towel. Detailed description of standard machine configurations for papermaking has been presented (Crotogino, R., et al., “Paprican's New Pilot Paper Machine,” Pulp & Papel Canada, Vol. 101, No. 10, 2000, pp. 48- 52).
    [0064] Briefly, the machine mainly consists of a twin wire roll forming section whose width is 0.46 m, a press section of three nozzles, four rolls and two Yankee dryers. For the production of CF films, it was observed that in the two suitable configurations, the fabric and towel mode was inferior in terms of economy because the removal of the press section brings a much more humid film to the drying section. It was observed that a single Yankee dryer was sufficient to dry the films, but those skilled in papermaking should realize that conventional dryers such as cylinders filled with rotating steam can be equally effective or superior for drying these films under controlled conditions.
    [0065] Unless otherwise specified, 1000 kg on a dry basis (od) of CF with not less than 50% by weight of its fibrillated material having lengths of up to 300 to 350 μm, diameters of approximately 100 to 500 nm and a consistency of 33 to 37% made from high consistency, multi-pass refining of a bleached softwood kraft pulp were dispersed with tap water in a dry end pulper/broken pulper in the paper machine (PM) press at 3 to 4% consistency and stored in a 50 m3 tank. The dispersed CF was then sent to the paper machine chest where the CF was diluted to about 2.0% consistency with tap water. A fan pump loop (after the PM chest) measured additional tap water and was diluted into the CF mud to 0.2 to 0.5% consistency. The CF stock was then sieved and sent to the PM Inbox. The headbox flow (800 to 5,000 L/min), machine speed (500 to 750 m/min) and other machine operating parameters have been adjusted to allow the formation of thin films with 6 to 8% and 9 at 10.5% solids content after the forming section without and with the use of vacuum boxes in the forming section, respectively, to achieve a solids content of 30 to 37% for the films after the press section and to produce the dry, water-redispersible CF films with a solids content of 80 to 85% and a basis weight of 15 to 22 g/m2 after the dryer section. The width of the dry CF films produced was 0.30 - 0.33 m and the first pass retention of the films was 85 to 90%. General procedure B: Laboratory dispersion of CF or CF films produced on a pilot paper machine in an aqueous medium
    [0066] Unless otherwise specified, 24 g (base od) of CF described in general procedure A or 24 g (base od) of the dry, water-redispersible CF films produced in accordance with general procedure A described were diluted to 1.2% consistency in a British disintegrator with a known amount of deionized water (H2O DI) whose temperature was raised to 80°C. The CF slurry was mixed at 3000 rpm for 15 minutes to give a dispersion which was then removed from the disintegrator and cooled to room temperature (~23°C). General Procedure C: Dispersion of CF or CF films produced by pilot paper machine in an aqueous medium in a pilot paper machine pulper
    [0067] Unless otherwise specified, 1000 kg (base od) of CF described in general procedure A, or 1000 kg (base od) of dry, water-redispersible CF films produced in accordance with general procedure A described were diluted to 3.0-4.0% consistency in a Press Broke pulper from the pilot paper machine (Beloit Vertical TriDyne Pres, Model No. 5201, Serial No. BC-1 100) or a dry end pulper with a known amount of tap H2O whose temperature has been raised to ~50°C. The CF slurry was mixed at 480 rpm for 15 minutes to give a dispersion which was removed from the pulper and stored in a 50 m3 tank, then cooled to room temperature (~23°C). General procedure D: Preparation of slides from a mixture of pulp and a CF product
    [0068] Unless otherwise specified, a hardwood kraft pulp (HWKP) in a dry loop form was first blended with H2O DI and repulped/crushed in a helical pulper at 10% consistency, 800 rpm and 50°C for 15 minutes. The repulped HWKP was then combined with a CF dispersion sample prepared according to general procedure B or C described in a weight ratio (od basis) of 96/4 (HWKP/CF) and with DI H2O to give a slurry of the pulp and FC at 0.33% consistency. Slides (60 g/m2) were prepared according to the PAPTAC test method, standard C.4. Blade tensile strengths were determined according to the PAPTAC test method, standard D.34. In a separate experiment, blades (60 g/m2) of 100% HWKP were also prepared and their tensile strengths measured. General Procedure E: Preparation of CF Films on a Standard Blade Machine
    [0069] A circular CF film with a size of 0.02 m2 was prepared using a modified PAPTAC.
    [0070] Test method, Standard C.5 as follows. Unless otherwise specified, 0.4, 0.8 or 1.2 g (base od) of CF prepared according to general procedure B or C described was diluted with DI H2O to give a CF slurry to a consistency of 0.05%. The dispersion was transferred on the standard blade machine equipped, unless otherwise specified, with a 150 mesh sieve using a Teflon spoon. The dispersion inside the standard blade machine was gently agitated and forced through the frame using a Teflon stick and then settled naturally. The standard blade machine drain valve was then released to allow water drainage and closed when the water drained out of the frame and a CF film was formed on top of the steel mesh. Typically, more than 90% of the cellulose filaments were retained in the CF film. The precise hold value depends on the total energy applied in preparing the CF and the sieve mesh size of the standard blade machine. For CF made from high-consistency, multi-pass refining of bleached softwood kraft pulp with a total specific refining energy of 5,000 to 10,000 kWh/t, the use of 150 mesh screens allows for retention of more than 90% of the filaments in the CF film. For CF made from high-consistency, multi-pass refining of bleached softwood kraft pulp with a total specific refining energy of 12,000 to 20,000 kVVh/t, the use of a 450 mesh screen allows retention of more than 90 % of filaments in CF film.
    The frame was opened and a Whatman #1 filter paper (185 mm in diameter) was placed on top of the wet CF film. Two blotters were placed on top of the filter paper and casting was applied using a casting plate and casting roller. 15 [for films made using 0.4 g (base od) of CF] or 22 [for films made using 0.8 or 1.2 g (base od) of CF] rear and front railings were applied before the casting plate and the two blotters were carefully removed. The filter paper with the CF film attached to it was then slowly peeled from the steel mesh.
    [0072] A glass polished stainless steel disc was placed against the side of the CF film.
    [0073] The pressing of the CF film was then performed according to the pressing procedure described in the PAPTAC test method, Standard C.5 with the first pressing and secondary pressing for 5.5 and 2.5 minutes, respectively.
    [0074] After pressing, the CF film that was pressed between the filter paper and the stainless steel plate was placed in drying rings and dried at a constant temperature and humidity (23°C and 50% relative humidity) all-night. The film, with a basis weight of approximately 20, 40 or 60 g/m2 of 0.4, 0.8 or 1.2 g (base od) of CF was then peeled from the steel plate and separated by peeling back and forward several times of the filter paper. EXAMPLE 1
    [0075] Cellulose filaments (CF) has been prepared to have not less than 50% by weight of its fibrillated material with lengths of up to 300 to 350 µm and diameters of approximately 100 to 500 nm of a softwood kraft pulp bleached by multi-pass refining, high consistency (33 to 37%) with a total specific refining energy of 78008000 kilowatt hours per ton of pulp (kvVh/t) using the previously described method PCT/CA2012/000060; WO 2012/097446 A1. Prepared FC, at a consistency of 33 to 37%, is referred to as FC never dry (1).
    [0076] A sample (1,000 kg base od) of the never-dried CF (1) was used to produce dried CF films on a pilot paper machine according to general procedure A described. The basis weight of the films was in a range of 15 to 22 g/m2, and the solids content of the films was in a range of 80 to 85%. Figure 2 shows a roll of dry CF film produced by pilot paper machine.
    A sample (24 g base od) of the never-dried CF (1) was dispersed in DI H2O according to general procedure B described to give a stable dispersion referred to as laboratory-dispersed never-dry CF (1).
    [0078] A sample (24 g base od) of the CF film produced by pilot paper machine (PM), dried was dispersed in DI H2O according to the general procedure B described. A stable dispersion was also formed. This CF dispersion is referred to as laboratory redispersed, PM dried CF (1).
    [0079] A sample (1000 kg base od) of dry CF film produced by PM pilot was dispersed in tap H2O in a Press Broke pilot paper machine pulper or dry end pulper according to general procedure C described . A stable dispersion was formed. This CF dispersion is referred to as pulper redispersed CF, dried at PM (1).
    [0080] In separate experiments, another CF was prepared to have lengths up to 300 to 350 μm and diameters from 100 to 500 nm of the same high consistency multi-pass refining softwood kraft pulp (36%) with a total refining energy of 8372 kvVh/t using the previously described method PCT/CA2012/000060; WO 2012/097446 A1. Prepared FC at a consistency of 36% is referred to as never dry FC (2). A sample of this CF (24 g base od) was dispersed in DI H 2 O according to general procedure B described to give a stable dispersion referred to as laboratory dispersed never-dry CF (2).
    [0081] A sample of the never-dried CF (2) was drum dried using a household clothes dryer for 3 h to give a dry CF with a solids content of 85.3%. This dry CF was redispersed in DI H2O according to general procedure B described to give a CF suspension referred to as drum dried laboratory redispersed CF (2).
    [0082] Blades (60 g/m2) were prepared according to the general procedure D described from a hardwood kraft pulp (HvVKP) and each of the CF dispersions described above and the CF suspension described above. The weight ratio (base od) of HvVKP and CF was 96/4. Slides (60 g/m2) were also prepared from 100% HvVKP. Table 1 lists the stress index values of the various blades determined according to general procedure D described. The data show that laboratory redispersed CF or PM pulper reddispersed CF, dry to PM retains more than 90% of the reinforcing power of never-dried, laboratory dispersed CF. Thus, forming CF films in a paper machine represents an economical means to produce a dry CF product that can be readily dispersed in an aqueous medium and used as a superior reinforcing agent for paper production.
    [0083] The data also show that drum-dried CF is much inferior to dry CF produced on the pilot paper machine in retaining the reinforcing power of never-dried CF. They also support the unexpected discoveries and novelties of the present invention in the production of dry, water-redispersible CF films in a paper machine. Table 1 - Tensile strengths of blades made of hardwood kraft pulp (HvVKP) without or with 4% CF.
    EXAMPLE 2
    [0084] Samples of the never-dried FC (2) described in example 1 were air-dried at room temperature (~23°C) for -120 h and air-dried in a GEA Barr-Rosin rapid pilot dryer at a speed rate of 100 kg/h, respectively, to give dry CF materials with solids content of 80.9 and 87.7%. These two dry CF materials were redispersed, respectively, in DI H2O according to the general procedure B described to give CF suspensions referred to as air dry CF, laboratory redispersed (2) and fast dry CF, laboratory redispersed (2) .
    [0085] Dry CF films (20 g/m2) were prepared on a standard blade machine according to the general procedure E described for each of these two CF suspensions and each of the CF dispersions and the CF suspension described in the example 1. The tensile index values of the films were determined according to PAPTAC test method, Standard D.34 and listed in table 2. The data clearly show that the CF films prepared from redispersion of the machine-produced dry CF films Pilot papers have nearly the same strength as CF films prepared from the never-dried CF dispersion. Thus, dry, water-redispersible CF films produced in a paper machine are recyclable. The data also show that air dry CF, drum dry CF or fast dry CF is much inferior to dry water redispersible CF produced on the pilot paper machine in the preparation of new and strong CF films. They also support the unexpected discoveries and novelty of the present invention in the production of water-redispersible, dry and recyclable CF films in a paper machine.
    [0086] In separate experiments, the various dry CF materials described previously in example 1 were dispersed in H2O DI according to the general procedure B described, except that the consistency used was 0.1% instead of 1.2%. Figure 3 shows the drawings of the dispersions or suspensions taken after 45 minutes of laying the never-dry CF dispersed in the laboratory, (1); b/ the FC redispersed in the laboratory, dried in PM (1); c/ the FC redispersed in the laboratory, dried in air (2); d/ o FC redispersed in laboratory, dried in drum (2); and the FC redispersed in laboratory, dry fast (2). The figures clearly show that dry CF films produced on a pilot paper machine have a water dispersibility identical or very similar to that of never-dried CF, while dry CF materials produced by air drying, drum drying or rapid drying have a lower water dispersibility than CF never dried or CF produced by a pilot paper machine. Again, they support the unexpected discovery and novelty of the present invention in the production of dry, water-redispersible and recyclable CF films in a paper machine. a standard blade machine

    EXAMPLE 3
    [0087] A new batch of cellulose filaments (CF) was prepared to have not less than 50% by weight of its fibrillated material with lengths of up to 300 to 350 μm and diameters of approximately 100 to 500 nm of a kraft pulp of High consistency, multi-pass refining softwood (28%) with a total refining energy of 8331 kWh/t using the method previously described (9). Prepared FC, at a consistency of 28%, is referred to as never-dry FC (3). A sample of this CF (24 g base od) was dispersed in DI H2O according to general procedure B described to give a stable dispersion referred to as laboratory-dispersed never-dry CF (3).
    [0088] Ten dry CF films (20 g/m2) of the never-dried, laboratory-dispersed CF (3) were prepared on a standard blade machine (SSM) according to the general procedure E described. Tensile index values of films were determined according to PAPTAC test method, Standard D.34. Additional dry CF films (110 in total) with basis weights of 20, 40 and 60 g/m2, respectively, were also prepared in an SSM according to the general procedure E described. These additional dry CF films were separately redispersed for each basis weight [20, 40 and 60 g/m2 (gsm)] in DI H2O according to general procedure B described to give three stable dispersions, referred to as dry CF in SSM 20 g, laboratory re-dispersed (3), CF dry in SSM 40 g, re-dispersed in laboratory (3), and CF dry in SSM 60 g, re-dispersed in laboratory (3), respectively. Ten dry CF films (20 g/m2) of each of these dispersions were prepared in an SSM according to general procedure E described. Tensile index values of films were determined according to PAPTAC test method, Standard D.34. The mean value and standard deviation of each set of ten dry films are listed in table 3. The data show that CF films produced by standard blade machine, dried with a basis weight of 20 to 60 g/m2 can be readily redispersed and used to produce new films with practically the same strength as films prepared from CF never dried. Table 3 - Tensile index of CF films (20 g/m2) made from CF never dried and CF films produced with blade machine standard (SSM) dried with different basis weights [g/m2 (gsm)]
    EXAMPLE 4
    [0089] Ten dry CF films (20 g/m2) of never-dried CF, dispersed in laboratory (3) and ten dry CF films (20 g/m2) of dry CF in 20 g SSM, redispersed in laboratory (3 ) described in example 3 were prepared on a standard blade machine according to general procedure E described, except that drying of the films was carried out in a speed dryer at 150°C for 30 seconds. Tensile index values of films were determined according to PAPTAC test method, Standard D.34. The mean value and standard deviation of each of the ten films, together with those of films dried at a constant temperature and humidity (CTH) (23°C and 50% relative humidity) throughout the night according to general procedure E described, are listed in table 4. The data shows that drying speed (temperature and time) has very little effect on the strength properties of CF films made from never-dried CF or from standard, re-dispersed blade machine dried CF. CF films produced by standard blade machine dried at high temperature/high speed can be readily redispersed and used to produce new films with virtually the same strength as prepared CF films never dried at different drying temperatures/speeds.Table 4 - Tensile index of CF films (20 g/m2) made from never-dried CF and CF films produced on a standard blade machine (SSM), dried on a standard blade machine and dried in a CTH environment or in a speed dryer
    EXAMPLE 5
    [0090] Samples (1.0 kg base od) of dry, water-redispersible CF film with a width of -30 cm produced on a pilot paper machine according to general procedure A described and referred to as PM-produced CF mesh were shredded into smaller films (approximately 2 cm x 2 cm) using a pilot plant shredder (Destroyit 4005 CC, IDEAL Krug & Priester GmbH & Co. KG, Simon-Schweitzer-StAe 34, 72336 Balingen, Germany). The shredded film (1.0 kg) was crushed to dry, water-redispersible CF powders of different sizes in a pilot plant crusher (Willy Mill No. 1, Arthur H. Thomas Co, Vine St. Phildelphia, Pa 19102, USA) equipped with screens with bore diameters of 3.2 mm, 2.0 mm, and 1.0 mm, respectively. Samples (20 g basis od per sample) of the CF film produced by PM and the CF powders, dry, redispersible in water (referred to as dry CF powders) obtained from the CF film produced by PM using the three different screens were dispersed , respectively, according to general procedure B. Ten dry CF films (20 g/m2) of each of the dispersed CF film produced by PM and the three dry dispersed CF powders were prepared in a blade machine standard according to the general procedure E described. Tensile index values of films were determined according to PAPTAC test method, Standard D.34. The mean value and standard deviation for each of the ten films are listed in table 5. The data show that the larger the mill wire hole diameter, the greater the stress index. Even without optimal optimization of crushing conditions, such as the hole diameter of the crusher screen, the accuracy of the knife blade and the residence time in the crusher, the dry CF powder obtained using the crusher equipped with a screen of diameter 3.2 mm hole retained 78% of the tensile index of the CF film produced by PM.Table 5 - Tensile index of the CF films (20 g/m2) made on a standard blade machine from the film samples of CF produced by PM and the dry CF powders obtained from the unraveling and grinding of the CF film produced by PM using a crusher equipped with screens of 1.0, 2.0 and 3.2 mm in diameter, respectively; before preparing the CF films dried on the standard blade machine the CF film produced in PM or the dry CF powders were dispersed according to general procedure B.

    [0091] The embodiments of the invention described above are considered exemplary. Those skilled in the art in this way will appreciate that the foregoing description is illustrative only and that various alternative configurations and modifications can be invented without departing from the spirit of the present invention. Thus, the present invention is to encompass all such alternative configurations, modifications and variances that fall within the scope of the appended claims.
    权利要求:
    Claims (11)
    [0001]
    1. Dry cellulose filament flakes comprising fibrillated filaments having a solids content of at least 80% by weight solids and at least 50% by weight of the filaments having a filament length of up to 350 µm; and a diameter between 100 and 500 nm, characterized by the fact that the filaments are produced in a paper making machine and that the filaments are additive free, free from derivatization, and form a stable dispersion in water in an aqueous medium and are redispersible in water so that the dried cellulose filaments form a stable water dispersion upon mechanical agitation in an aqueous medium at room or elevated temperature.
    [0002]
    2. Flakes according to claim 1, characterized in that the three-dimensional format is from 0.01 mm to 2.0 cm.
    [0003]
    3. Flakes according to claim 1, characterized in that at least 75% by weight of the filaments comprises a filament length of up to 350 µm; and a diameter between 100 and 500 nm.
    [0004]
    4. Flakes according to claim 1, characterized in that the length of the filament is between 300 and 350 µm.
    [0005]
    5. Flakes according to claim 1, characterized in that the filaments are at least 95% solids by weight.
    [0006]
    6. A method for preparing a dry film of cellulose filaments comprising: providing a liquid suspension of the fibrillated cellulose filaments produced by high consistency, multi-pass refining of wood or plant fibers, wherein at least 50% by weight of the filaments comprise a filament length of up to 350 µm; and a filament diameter between 100 and 500 nm, and characterized by the fact that more than 90% of the filaments are retained in a forming section of a paper-making machine, and that the film forms a medium-stable water dispersion. aqueous and is redispersible in water, where filaments are free from additives and derivatization.
    [0007]
    7. Method according to claim 6, characterized in that the thickness is from 10 to 300 µm.
    [0008]
    8. The method of claim 6, characterized in that the papermaking machine is a standard blade machine with a 150 to 400 mesh screen.
    [0009]
    9. Method according to claim 6 or 7, characterized in that it further comprises pressing the film in a press section of the machine to produce a pressed film.
    [0010]
    10. Method according to claim 9, characterized in that it further comprises drying the pressed film in at least one dryer section of the machine to produce the dry film.
    [0011]
    11. Method according to any one of claims 6, 7, 9 or 10, characterized in that the paper making machine operates at a speed of 500 to 1,500 m/min.
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    同族专利:
    公开号 | 公开日
    CN104838050A|2015-08-12|
    US9803320B2|2017-10-31|
    CA2889991C|2016-09-13|
    CN104838050B|2016-11-02|
    JP6283370B2|2018-02-21|
    EP2917390A1|2015-09-16|
    BR112015010341A2|2017-07-11|
    KR20150082523A|2015-07-15|
    JP2016503465A|2016-02-04|
    AU2013344245A1|2015-05-07|
    RU2015121724A|2017-01-10|
    KR102229332B1|2021-03-18|
    CA2889991A1|2014-05-15|
    EP2917390A4|2016-07-27|
    EP2917390B1|2019-12-25|
    AU2013344245B2|2017-03-02|
    US20150275433A1|2015-10-01|
    RU2628382C2|2017-08-16|
    WO2014071523A1|2014-05-15|
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    法律状态:
    2018-03-06| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2018-03-13| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2018-03-20| B06I| Publication of requirement cancelled [chapter 6.9 patent gazette]|Free format text: ANULADA A PUBLICACAO CODIGO 6.6.1 NA RPI NO 2462 DE 13/03/2018 POR TER SIDO INDEVIDA. |
    2019-10-01| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2021-07-20| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-08-24| 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 07/11/2013, OBSERVADAS AS CONDICOES LEGAIS. |
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    US201261723517P| true| 2012-11-07|2012-11-07|
    US61/723,517|2012-11-07|
    PCT/CA2013/050853|WO2014071523A1|2012-11-07|2013-11-07|Dry cellulose filaments and the method of making the same|
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