JP2013249341A - Fiber composite material and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber composite material where cellulose fibers are dispersed uniformly, and to provide a resin composite material that contains the fiber composite material and a matrix resin.SOLUTION: A fiber composite material contains: a water-soluble or hydrophilic thermoplastic resin; and cellulose fibers dispersed in the thermoplastic resin. A resin composite material contains the fiber composite material and a matrix resin.

Description

  The present invention relates to a fiber composite material containing cellulose fibers useful for improving various physical properties of a resin, and a resin composite material including the fiber composite material and a matrix resin.

  Conventionally, organic or inorganic granular fillers or fibrous fillers have been blended for improving the physical properties of resins, for example, improving mechanical strength such as elastic modulus and bending strength, and reducing thermal expansion coefficient. . Furthermore, with the development of fine particle production technology, silica or metal fine particles, or whisker type fillers have been actively mixed. In recent years, in place of these fillers, it is possible to use cellulose fibers dispersed in a resin, which is excellent in improving mechanical properties such as high strength, high elasticity, low thermal expansion, is easily available, and is environmentally friendly. It has been actively studied.

  In order to obtain a resin molded body in which cellulose fibers are dispersed in a resin, as a conventional technique for mixing cellulose fibers and a resin, for example, cellulose fibers are wet pulverized in water, and then water is converted into a resin-soluble solvent. A method is disclosed in which a cellulose film substituted in stages is prepared, and a resin monomer solution is immersed in the film and then cured (Patent Document 1). Also, a method of producing a molded product by dispersing cellulose fibers and dissolving a resin in a solvent having dispersibility of cellulose fibers and resin solubility, mixing, and then removing the solvent (Patent Document 2), A resin composite material (Patent Document 3) containing microfibrillated cellulose surface-treated with a hydrophilic resin is also disclosed.

JP 2006-241450 A JP 2008-024795 A JP 2008-184492 A

  Cellulose fibers, for example, have the property that even if they are dispersed once in a solvent such as water, the fibers aggregate together when dried or mixed with a resin. As a result, the resin may not exhibit the desired performance. Therefore, when mixing cellulose fiber and resin, it is necessary to disperse cellulose fiber uniformly in resin.

  However, according to conventional techniques such as the methods of Patent Documents 1 and 2, since the cellulose fibers themselves are not treated to prevent aggregation, the cellulose fibers may not be uniformly dispersed when mixed with the resin. Further, since the hydrophilic resin proposed in Patent Document 3 does not have thermoplasticity, there is a concern about processability and a decrease in strength at the interface between the matrix resin and the fiber.

  Accordingly, an object of the present invention is to provide a fiber composite material in which cellulose fibers are uniformly dispersed, and a resin composite material including the fiber composite material and a matrix resin.

  As a result of diligent investigations on the above problems, the present inventors have inhibited hydrogen bonding between cellulose fibers by making hydrophilic or water-soluble thermoplastic resin affinity with hydroxyl groups or methylol groups possessed by cellulose itself. Thus, the inventors have found that aggregation can be prevented, and as a result, the cellulose fibers can be uniformly dispersed in the resin.

That is, the present invention
Item 1. A fiber composite material containing a water-soluble or hydrophilic thermoplastic resin and cellulose fibers dispersed in the thermoplastic resin;
Item 2. Item 2. The fiber composite material according to Item 1, wherein the thermoplastic resin has a melting point or softening point of 40 to 120 ° C.
Item 3. Item 3. The fiber composite material according to Item 1 or 2, wherein the thermoplastic resin is at least one selected from associative polyurethane, crosslinked polyurethane, and copolymer nylon;
Item 4. Item 4. The fiber composite material according to any one of Items 1 to 3, wherein the cellulose fiber is a water-containing material having a water content of 30% by mass or more;
Item 5. Item 5. The fiber composite material according to any one of Items 1 to 4, wherein the cellulose fiber content is 0.5 to 50% by mass relative to the entire fiber composite material;
Item 6. A method for producing a fiber composite material in which cellulose fibers are added to a thermoplastic resin and kneaded at 40 to 130 ° C. to disperse the cellulose fibers in the thermoplastic resin;
Item 7. Item 7. A resin composite material comprising the fiber composite material according to any one of Items 1 to 5 and a matrix resin; The present invention relates to a resin molded article obtained by molding the resin composite material according to Item 7.

  ADVANTAGE OF THE INVENTION According to this invention, when it mixes with matrix resin, the fiber composite material which does not aggregate or has few aggregation parts can be provided. Therefore, when the fiber composite material and the matrix resin are mixed, the cellulose fibers can be uniformly dispersed in the resin, and improvement of the physical properties of the resin expected by blending the cellulose fibers, for example, elastic modulus and bending Effects such as improvement of mechanical strength such as strength and reduction of thermal expansion coefficient are exhibited as expected.

  The fiber composite material of the present invention contains a water-soluble or hydrophilic thermoplastic resin and cellulose fibers dispersed in the thermoplastic resin.

  The water-soluble or hydrophilic thermoplastic resin used in the present invention is not particularly limited as long as it is water-soluble or hydrophilic and is a thermoplastic resin. For example, associative polyurethane, cross-linked polyurethane, copolymer Nylon, polyethylene oxide, hydrolyzate of ethylene vinyl acetate copolymer, maleic anhydride modified polyolefin and the like. These water-soluble or hydrophilic thermoplastic resins may be used alone or in combination of two or more.

  The reason why the water-soluble or hydrophilic thermoplastic resin inhibits the aggregation of cellulose fibers is not clear, but the water-soluble or hydrophilic thermoplastic resin is dissolved or swollen by the water in which the cellulose fibers are dispersed. As a result, the affinity with cellulose is further increased, and the water-soluble or hydrophilic thermoplastic resin itself has a strong cohesive force. Therefore, once mixed and inserted between cellulose fibers, the effect of inhibiting the aggregation of cellulose fibers is inhibited. It is thought that there is.

  As the water-soluble or hydrophilic thermoplastic resin, a resin having a melting point or a softening point of 40 to 120 ° C. is preferably used from the viewpoint of dispersibility of cellulose fibers.

  Examples of the water-soluble thermoplastic resin include associative polyurethane and polyethylene oxide.

  Associative polyurethane is a water-soluble polyalkylene oxide modified product obtained by reacting a polyalkylene oxide compound, two monovalent hydrophobic alcohols (A, B) having 6 to 24 carbon atoms and a diisocyanate compound.

  The number average molecular weight of the polyalkylene oxide compound is preferably 4,000 to 30,000, and more preferably 6,000 to 20,000. When the number average molecular weight of the polyalkylene oxide compound is less than 4,000, the melt viscosity of the resulting polyalkylene oxide modified product is lowered, and the processability may be lowered. When the number average molecular weight of the polyalkylene oxide compound exceeds 30,000, the resulting polyalkylene oxide modified product has a high melt viscosity, which may deteriorate the workability.

  As the monovalent hydrophobic alcohol (A), an alcohol having an alkyl group such as a linear alkyl group having 6 to 10 carbon atoms or a branched alkyl group and having a solubility in water of 0.4% by mass or less. Can be mentioned. Examples include hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol and the like, and octyl alcohol and decyl alcohol are preferably used.

  Examples of the monovalent hydrophobic alcohol (B) include alcohols having an alkyl group such as a linear alkyl group having 11 to 24 carbon atoms and a branched alkyl group and having a solubility in water of 20 mass ppm or less. Examples include undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecyl alcohol, aralkyl alcohol, 2-octyldodecanol, and behenyl alcohol. Cetyl alcohol and behenyl alcohol are preferably used. The total amount of the two types of monohydric alcohol used is preferably 1.2 to 2.5 mol, more preferably 1.5 to 2.2 mol, relative to 1 mol of the polyalkylene oxide compound. When the total amount of the two types of monovalent hydrophobic alcohol used is less than 1.2 mol, the melt viscosity of the resulting polyalkylene oxide modified product is lowered, and the processability may be lowered. When the total amount of the two types of monovalent hydrophobic alcohol used exceeds 2.5 mol, the melt viscosity of the resulting polyalkylene oxide modified product becomes high, and the processability may be reduced.

  The diisocyanate compound has a methyldiphenyl group, a hexamethylene group, a methyldicyclohexylene group, a 3-methyl-3,5,5-trimethylcyclohexylene group, a dimethylphenylene group, or a tolylene group. Specific examples of the diisocyanate compound include 4,4′-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), dicyclohexylmethane-4,4′-diisocyanate (HMDI), 3-isocyanate methyl- Examples include 3,5,5-trimethylcyclohexyl isocyanate (IPDI) and 2,4-tolylene diisocyanate (TDI). Dicyclohexylmethane-4,4'-diisocyanate (HMDI) and 1,6-hexamethylene diisocyanate (HDI) are preferred.

  The ratio of the isocyanate compound used is the ratio of the number of moles of isocyanate groups ([-NCO]) to the total number of moles of terminal OH groups of the polyalkylene oxide compound and two monovalent hydrophobic alcohol compounds ([- NCO] / [OH]) is preferably 0.80 to 1.35, more preferably 0.90 to 1.20. When the ratio is less than 0.8, the remaining amount of unreacted monovalent hydrophobic alcohol is increased, and the melt viscosity of the resulting polyalkylene oxide modified product is lowered, and the processability may be deteriorated. When the said ratio exceeds 1.35, there exists a possibility that the melt viscosity of the polyalkylene oxide modified product obtained may become high, and workability may deteriorate.

  Specific examples of the associative polyurethane include “Acpec HU type C” manufactured and sold by Sumitomo Seika Co., Ltd.

  The polyethylene oxide preferably has a viscosity average molecular weight of 100,000 to 1,500,000, more preferably 150,000 to 1,000,000 from the viewpoint of processability. Specifically, "PEO-1", "PEO-3" etc. which are manufactured and sold by Sumitomo Seika Co., Ltd. are mentioned, for example.

  Examples of the hydrophilic thermoplastic resin include cross-linked polyurethane, copolymer nylon, hydrolyzate of ethylene vinyl acetate copolymer, maleic anhydride-modified polyolefin, and the like.

 The crosslinked polyurethane is not particularly limited as long as it is produced by a reaction between an isocyanate compound and an active hydrogen compound and is generally commercially available or produced. As the isocyanate compound, a polyfunctional isocyanate compound having two or more isocyanate groups is preferable. Moreover, an aliphatic isocyanate compound is suitably used from the viewpoint of safety.

  Examples of the active hydrogen compound include polyalkylene oxide having two or more hydroxyl groups. You may use these in mixture of 2 or more types.

  In the present invention, a cross-linked polyurethane produced by using a polyalkylene oxide having a relatively large molecular weight as a polyalkylene oxide and adding a polyol compound is preferable. More specifically, for example, a cross-linked polyurethane obtained by reacting a polyalkylene oxide having a mass average molecular weight of 500 to 500,000, 1,4-butanediol and dicyclohexylmethane-4,4′-diisocyanate can be used. . The cross-linked polyurethane obtained by the above method is soluble in an aqueous alcohol solution and further has water absorption.

  Examples of the polyalkylene oxide having a mass average molecular weight of 500 to 500,000 include polyethylene oxide, polypropylene oxide, and ethylene oxide / propylene oxide copolymer. In particular, polyethylene oxide, polypropylene oxide and ethylene oxide / propylene oxide copolymers having a mass average molecular weight of 2,000 to 100,000 are preferably used.

  If the mass average molecular weight is less than 500, the melt viscosity of the resulting cross-linked polyurethane is too low, and the processability may decrease.

  In the present invention, the proportion of dicyclohexylmethane-4,4′-diisocyanate used in the reaction of polyalkylene oxide having a mass average molecular weight of 500 to 500,000, 1,4-butanediol, and dicyclohexylmethane-4,4′-diisocyanate is as follows: The ratio (R value) between the number of moles of isocyanate groups of dicyclohexylmethane-4,4′-diisocyanate isocyanate and the sum of the number of moles of terminal hydroxyl groups of polyalkylene oxide and hydroxyl groups of 1,4-butanediol (− NCO group / -OH group) is preferably selected from the range of 0.5 to 3.0, and preferably from 0.7 to 2.0. The number of moles of polyalkylene oxide and polyol compound can be determined by dividing the mass by the mass average molecular weight.

  As a method of reacting a polyalkylene oxide having a mass average molecular weight of 500 to 500,000, 1,4-butanediol and dicyclohexylmethane-4,4′-diisocyanate, an appropriate solvent such as toluene, xylene, dimethylformamide or the like is used. The reaction can be carried out in the form of a solution, but it can also be carried out in a dispersed manner, or after mixing both uniformly in a powder or solid form, the reaction can be carried out by heating to a predetermined temperature. From the viewpoint of industrial implementation, a method in which each raw material is continuously supplied in a molten state and mixed and reacted in a multi-screw extruder is preferable. The temperature of the above reaction is usually 70 to 210 ° C. The reaction can be accelerated by adding a small amount of triethylamine, triethanolamine, dibutyltin diacetate, dibutyltin dilaurate, stannous octoate, triethylenediamine, or the like to the reaction system.

  The reaction of a polyalkylene oxide having a weight average molecular weight of 500 to 500,000, 1,4-butanediol and dicyclohexylmethane-4,4′-diisocyanate is carried out in a mixture of the polyalkylene oxide and 1,4-butanediol. , Dicyclohexylmethane-4,4′-diisocyanate may be reacted.

  Specific examples of the cross-linked polyurethane include “Aqua Coke” manufactured and sold by Sumitomo Seika Co., Ltd., “Yuriano” manufactured and sold by Arakawa Chemical Industries, Ltd., and the like.

  Examples of the copolymer nylon include those obtained by a condensation polymerization reaction of caprolactam, laurolactam, dicarboxylic acid and diamine (such as hexamethylenediamine) and having a melting point of 100 ° C. Specific examples include “Grilltex D1649A” manufactured and sold by MMS.

  As the raw material cellulose of the cellulose fiber used in the present invention, plants (for example, wood, bamboo, hemp, jute, kenaf, farmland waste, cloth, pulp, recycled pulp, waste paper), animals (for example, ascidians), algae Those originating from microorganisms (for example, acetic acid bacteria (Acetobacter)), microorganism products, etc. are known, and any of them can be used in the present invention. Preferred is cellulose derived from plants or microorganisms, and more preferred is cellulose derived from plants.

  Examples of the cellulose fiber used in the present invention include those produced by various known methods. For example, it is produced by mechanically defibrating cellulose with a high-pressure homogenizer, a grinder, a ball mill, high-pressure jet water or the like. Moreover, it manufactures by performing defibration by chemical methods, such as a TEMPO catalyst, and performing defibration using an ionic liquid. In addition, in this invention, as long as a cellulose is a fiber state, about the manufacturing method, there is no restriction | limiting, You may use a commercially available thing.

  Commercially available products include “BiNF-IS Cellulose, cellulose content 5%” manufactured by Sugino Machine, “Cerish KY-100G, cellulose content 10%” manufactured by Daicel Corporation, “TEMPO oxidized pulp product, cellulose content manufactured by Nippon Paper Industries, Ltd.” 7% "and the like.

  The average fiber diameter of the cellulose fibers used in the present invention is preferably 10 nm to 300 μm, more preferably 20 nm to 200 μm, still more preferably 25 nm to 100 μm. Further, the length of the cellulose fiber is not particularly limited, but the average fiber length is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more. The aspect ratio (fiber length / fiber width) of the cellulose fiber is preferably 10 to 10,000, and more preferably 20 to 5,000. When the aspect ratio is less than 10, the dispersion state may be deteriorated.

  In the fiber composite material of the present invention, the content of the cellulose fiber is preferably 0.5 to 50% by mass and more preferably 1 to 40% by mass with respect to the entire fiber composite material. When the content of the cellulose fiber exceeds 50% by mass, there is a possibility that processability is lowered when a fiber composite material is produced, and an appropriate fiber composite material cannot be obtained. When the content of the cellulose fiber is less than 0.5% by mass, there is a possibility that the effect of weight reduction and strength increase, which are the addition effect of the cellulose fiber, cannot be exhibited.

  The fiber composite material of the present invention can be produced by a method of adding cellulose fibers to a water-soluble or hydrophilic thermoplastic resin, kneading at 40 to 130 ° C., and dispersing the cellulose fibers in the thermoplastic resin.

  Although the property of the cellulose fiber is not particularly limited, a water-containing material having a water content of 30% by mass or more is preferably used from the viewpoints of easy handling and availability. Among these, for example, in the case of a cellulose fiber having a fiber diameter of nm size, an aqueous dispersion having a water content of preferably 80% by mass or more, more preferably 90 to 99.5% by mass is preferably used. In the case of a cellulose fiber having a diameter of μm, a water-wet material having a water content of preferably 40 to 80% by mass, more preferably 70 to 80% by mass is used.

  It is presumed that by adding cellulose fibers in an aqueous dispersion or water-wet body, the thermoplastic resin swells or becomes hydrophilic due to moisture, improves compatibility with cellulose fibers, and enables micro-dispersion of cellulose fibers. The As a result, mechanical strength increases such as tensile strength and bending stress, which are the effects of adding cellulose fibers, are more efficiently exhibited.

  The processing temperature at the time of kneading the thermoplastic resin and the cellulose fiber is preferably 40 to 130 ° C. which is equal to or higher than the melting point or softening point of the thermoplastic resin from the viewpoint of preventing aggregation of the cellulose fiber and efficiently removing moisture, 50-120 degreeC is more preferable.

  If the processing temperature is less than 40 ° C., it takes time to remove the moisture, which is not efficient. If the processing temperature exceeds 130 ° C., the moisture rapidly evaporates and the cellulose fibers may partially aggregate.

  A method for kneading the thermoplastic resin and the cellulose fiber is not particularly limited, and examples thereof include a method for kneading using a vent type twin screw extruder, a Banbury mixer, a kneader, a kneading roll, and the like.

  In the fiber composite material of the present invention, as long as the effect is not impaired, the additives include an antioxidant, an anti-shrink agent, an antistatic agent, an ultraviolet absorber, a heat stabilizer, a weather stabilizer, and a release agent. , Lubricants, impact modifiers, plasticizers, flame retardants, antibacterial agents, preservatives, and the like may be added as appropriate.

  The fiber composite material thus obtained is mixed with a matrix resin to obtain the resin composite material of the present invention.

  Examples of the matrix resin include those generally used as commercially available or manufactured general-purpose plastics. For example, polyethylene (PE), high density polyethylene, medium density polyethylene, low density polyethylene, polypropylene (PP), polyurethane ( PU), polyvinyl chloride (PVC), polyvinylidene chloride, polystyrene (PS), polyvinyl alcohol (PVA), polyvinyl acetate (PVAc), Teflon (registered trademark; polytetrafluoroethylene, PTFE), acrylonitrile butadiene styrene resin ( ABS resin), acrylonitrile styrene resin (AS resin), polymethyl methacrylate (PMMA), hydrolyzate of ethylene vinyl acetate copolymer (EVA), polyamide (PA), copolymer nylon, maleic anhydride modified Reolefin, polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (m-PPE, modified PPE, PPO), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), glass fiber reinforced polyethylene terephthalate (GF-PET) , Cyclic polyolefin (COP), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polysulfone, polyethersulfone, amorphous polyarylate, liquid crystal polymer, polyetheretherketone, thermoplastic polyimide (PI), and polyamide An imide (PAI) etc. are mentioned.

  Of these, the preferred matrix resin is preferably a thermoplastic resin, among which polypropylene (PP), polyethylene (PE), polyamide (PA), copolymer nylon, maleic anhydride modified polyolefin, polycarbonate (PC), ethylene vinyl acetate. A hydrolyzate of a copolymer (EVA) and polymethyl methacrylate (PMMA) are mentioned.

  As a hydrolyzate of ethylene vinyl acetate copolymer (EVA), ethylene vinyl acetate copolymer is saponified with caustic soda, has a hydroxyl group and an acetoxy group in the molecular chain, and has an ethylene content of 80 to 95 mol%. The degree is 20 to 100%. Specific examples include “Mersen H” manufactured and sold by Tosoh Corporation.

  Examples of the maleic anhydride-modified polyolefin include those obtained by grafting maleic anhydride onto a polyolefin and having a melting point of 80 to 120 ° C. Specific examples include “Admer PF508” manufactured and sold by Mitsui Chemicals, Inc.

  In the resin composite material of the present invention, the content of the fiber composite material is preferably 1 to 40% by mass, more preferably 2 to 35% by mass, as the content of cellulose fibers with respect to the entire resin composite material. More preferably, it is 3-30 mass%. When content as a cellulose fiber is less than 1 mass%, there exists a possibility that improvement of mechanical strength, such as an elasticity modulus and bending strength, cannot be expected. When the content as the cellulose fiber exceeds 40% by mass, the strength of the resin composite is lowered and becomes brittle, and there is a possibility that it cannot be put into practical use.

  A method of mixing the fiber composite material and the matrix resin is not particularly limited, and examples thereof include a method of kneading using a vent type twin screw extruder, a Banbury mixer, a kneader, a kneading roll, or the like.

  The resin molded body of the present invention obtained by molding the resin composite material thus obtained by a conventional method includes those in the shape of film, foam, etc., and is used in industrial fields such as electric / electronics, machinery, automobiles and building materials. Widely used as a reinforcing material.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(2)引張応力(MPa):２％ひずみおよび５％ひずみ時の引張応力
(3)破断応力(MPa):破断時の引張応力
(4)破断ひずみ(%):破断時の伸び [Evaluation method]
1. Tensile test: Based on JIS K7161, the tensile modulus, tensile stress, rupture stress, and rupture strain were measured using the following test pieces and measuring devices.
Test piece: 1BA type (small test piece)
Measuring instrument: Shimadzu Autograph AGS-J type

(2) Tensile stress (MPa): Tensile stress at 2% strain and 5% strain
(3) Breaking stress (MPa): Tensile stress at break
(4) Breaking strain (%): Elongation at break

2.3 Point bending test: Based on JIS K7171, the bending stress was measured using the following test pieces and measuring devices.
Test piece: ISO527-2-1A
Measuring instrument: Shimadzu Autograph AGS-J type
(1) Bending stress (MPa): Bending stress when the deflection is 1mm, 2mm, 3mm, 4mm, 5mm

Example 1
After winding 28 g of cross-linked polyurethane (“Aqua Coke TWB” manufactured by Sumitomo Seika, softening point 60 ° C.) on a 4-inch test roll (90 ° C.), a commercially available cellulose nanofiber (CeNF) aqueous dispersion (manufactured by Sugino Machine) 226.4 g of “BiNF-IS cellulose, concentration 5.3 mass%” was added, and kneaded for 30 minutes while evaporating water to obtain a fiber composite material. Using the obtained fiber composite material, a press sheet (CeNF content: 30% by mass) of 100 × 100 × 2 mmt was produced by a press. A test piece for measuring physical properties was prepared from the obtained sheet, and physical properties were evaluated. The evaluation results are shown in Table 1.

(Example 2)
After winding 28g of associative polyurethane ("Acpec HU type C", manufactured by Sumitomo Seika, softening point 60 ° C) on a 4-inch test roll (90 ° C), 48g of water was added to 12g of cotton linter (Bakakai). Then, an aqueous dispersion containing 20% by mass of cellulose fiber obtained by treating with a disper at 5,000 rpm for 5 minutes was added, and kneaded for 30 minutes while evaporating water to obtain a fiber composite material. Test specimens for measuring physical properties were prepared in the same manner as in Example 1, and physical properties were evaluated. The evaluation results are shown in Table 1.

(Example 3)
After winding 28 g of copolymer nylon (“Grilltex D1649AG” manufactured by MMS Co., Ltd., 90 ° C.) on a 4-inch test roll (100 ° C.), a commercially available cellulose nanofiber aqueous dispersion (“Selish KY” manufactured by Daicel Finechem Co., Ltd.) −100 G, concentration 10 mass% ”) 120 g was added, and kneaded for 30 minutes while evaporating water to obtain a fiber composite material. Test specimens for measuring physical properties were prepared in the same manner as in Example 1, and physical properties were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 1)
In Example 1, physical properties were evaluated in the same manner as in Example 1 except that cellulose nanofibers were not added. The evaluation results are shown in Table 1.

(Comparative Example 2)
In Example 2, physical properties were evaluated in the same manner as in Example 2 except that no cotton linter was added. The evaluation results are shown in Table 1.

(Comparative Example 3)
In Example 3, physical properties were evaluated in the same manner as in Example 3 except that cellulose nanofibers were not added. The evaluation results are shown in Table 1.

Example 4
12 g of the fiber composite material produced in Example 1 and 28 g of a hydrolyzate of ethylene vinyl acetate copolymer (EVA) (manufactured by Tosoh Corporation, “Mersen H H68224”) were kneaded with a 4-inch test roll at 100 ° C. for 10 minutes. A resin composite material was obtained. Using the obtained resin composite material, a press sheet (CeNF content: 9% by mass) of 100 × 100 × 2 mmt was produced by a press. A test piece for measuring physical properties was prepared from the obtained sheet, and physical properties were evaluated. The evaluation results are shown in Table 1.

(Example 5)
The physical properties were the same as in Example 4 except that 28 g of copolymer nylon (“Grilltex D1649AG” manufactured by Emus Co., Ltd.) was used instead of the hydrolyzate of ethylene vinyl acetate copolymer (EVA) in Example 4. Evaluation was performed. The evaluation results are shown in Table 1.

(Example 6)
12 g of the fiber composite material prepared in Example 2 and 28 g of maleic anhydride-modified polyolefin (manufactured by Mitsui Chemicals, Inc., “Admer PF508”) were kneaded with a 4-inch test roll at 100 ° C. for 10 minutes to obtain a resin composite material. Using the obtained resin composite material, a press sheet (CeNF content: 9% by mass) of 100 × 100 × 2 mmt was produced by a press. A test piece for measuring physical properties was prepared from the obtained sheet, and physical properties were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 4)
In Example 4, in place of 12 g of the fiber composite material prepared in Example 1, 8.4 g of a crosslinked polyurethane (“Aqua Coke TWB” manufactured by Sumitomo Seika, softening point 60 ° C.) was used. The same operation was performed, and physical properties were evaluated. The evaluation results are shown in Table 1.

(Comparative Example 5)
In Example 4, in place of 12 g of the fiber composite material prepared in Example 1, 8.4 g of a crosslinked polyurethane (“Aqua Coke TWB” manufactured by Sumitomo Seika Co., Ltd., softening point: 60 ° C.) was used. The physical properties were evaluated in the same manner as in Example 4 except that 28 g of copolymer nylon (“Grilltex D1649AG” manufactured by Emus Co., Ltd.) was used instead of the hydrolyzate of (EVA). The evaluation results are shown in Table 1.

(Comparative Example 6)
In Example 6, in place of the fiber composite material 12 g produced in Example 2, 6.4 g of associative polyurethane (“Appec HU type C” manufactured by Sumitomo Seika, softening point 60 ° C.) was used. The physical properties were evaluated in the same manner as described above. The evaluation results are shown in Table 1.

(Example 7)
1.33 g of the fiber composite material prepared in Example 1 and 18.67 g of a cross-linked polyurethane (“Aqua Coke TWB” manufactured by Sumitomo Seika, softening point 60 ° C.) are used in a twin-screw extruder (manufactured by Leo Lab, DSM Xplore). The resin composite material was obtained by kneading at 180 ° C., 100 rpm for 5 minutes. Using the obtained resin composite material, a test piece for measuring three-point bending stress (CeNF content: 2% by mass) was prepared by an injection molding machine, and physical properties were evaluated. The evaluation results are shown in Table 2.

(Example 8)
6 g of the fiber composite material prepared in Example 1 and 12.6 g of polypropylene (PP) (manufactured by Sumitomo Chemical Co., Ltd., “Nobrene AZ564”) and 1.4 g of a compatibilizer (manufactured by Mitsui Chemicals, Inc., “Admer QE800”) A resin composite material was obtained by kneading at 180 ° C. and 100 rpm for 5 minutes using a shaft extruder (manufactured by Leo Labo, DSM Xplore), and the resin composite material was used to measure a three-point bending stress with an injection molding machine. A test piece (CeNF content: 9% by mass) was prepared and evaluated for physical properties, and the evaluation results are shown in Table 2.

Example 9
In Example 8, it replaced with 6g of fiber composite materials produced in Example 1, and operated similarly to Example 8 except having used the fiber composite material 6g produced in Example 3, and implemented physical property evaluation. The evaluation results are shown in Table 2.

(Example 10)
In Example 8, it replaced with 6g of fiber composite materials produced in Example 1, and operated similarly to Example 8 except having used the fiber composite material 6g produced in Example 2, and implemented physical-property evaluation. The evaluation results are shown in Table 2.

(Comparative Example 7)
Resin composite containing kneaded cross-linked polyurethane (Sumitomo Seika "Aqua Coke TWB", softening point 60 ° C) with a twin screw extruder (Leo Lab, DSM Xplore) at 180 ° C, 100 rpm for 5 minutes. Obtained material. Using the obtained resin composite material, a test piece for three-point bending stress measurement was prepared by an injection molding machine, and physical properties were evaluated. The evaluation results are shown in Table 2.

(Comparative Example 8)
In Example 8, in place of 6 g of the fiber composite material prepared in Example 1, the same operation as in Example 8 was performed except that 6 g of a crosslinked polyurethane (“Aqua Coke TWB” manufactured by Sumitomo Seika) was used, and physical properties were evaluated. Carried out. The evaluation results are shown in Table 2.

(Comparative Example 9)
In Example 9, in place of 6 g of the fiber composite material produced in Example 3, the same operation as in Example 9 was performed except that 6 g of copolymer nylon (“Grilltex D1649AG” manufactured by EMS Co., Ltd.) was used. Carried out. The evaluation results are shown in Table 2.

(Comparative Example 10)
In Example 10, in place of 6 g of the fiber composite material produced in Example 2, 6 g of associative polyurethane (“Acpec HU type C” manufactured by Sumitomo Seika) was used. Evaluation was performed. The evaluation results are shown in Table 2.

  According to the present invention, it is possible to provide a fiber composite material that does not agglomerate or has very little agglomeration when mixed with a resin. Therefore, when the fiber composite material and the resin are mixed, the cellulose fibers can be uniformly dispersed. Improvement of the physical properties of the resin expected by blending the cellulose fibers, for example, a machine such as elastic modulus and bending strength Effects such as improvement of mechanical strength and reduction of thermal expansion coefficient are exhibited as expected.

Claims (8)

  A fiber composite material comprising a water-soluble or hydrophilic thermoplastic resin and cellulose fibers dispersed in the thermoplastic resin.   The fiber composite material according to claim 1, wherein the melting point or softening point of the thermoplastic resin is 40 to 120 ° C.   The fiber composite material according to claim 1 or 2, wherein the thermoplastic resin is at least one selected from associative polyurethane, crosslinked polyurethane, and copolymer nylon.   The fiber composite material according to any one of claims 1 to 3, wherein the cellulose fiber is a hydrous material having a water content of 30% by mass or more.   Content of a cellulose fiber is 0.5-50 mass% with respect to the whole fiber composite material, The fiber composite material of any one of Claims 1-4.   A method for producing a fiber composite material in which cellulose fibers are added to a thermoplastic resin, kneaded at 40 to 130 ° C., and the cellulose fibers are dispersed in the thermoplastic resin.   A resin composite material comprising the fiber composite material according to claim 1 and a matrix resin.   A resin molded body formed by molding the resin composite material according to claim 7.