JP2010084281A - Fibrous reinforcing agent and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber-like reinforcing agent which has a high degree of dispersive properties over a matrix resin while capable of effectively reinforcing the matrix resin. <P>SOLUTION: The fiber-like reinforcing agent contains microfibers (A) and (B), which can be obtained by making a mechanical shearing force act on a cellulosic fiber (A) and a synthetic resin fiber (B) within a solvent. The fiber (B) can be of olefin type split fiber. The solid content weight ratio of the cellulosic fiber (A) to the fiber (B) can be 10/90 to 90/10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fibrous reinforcing agent useful for improving the mechanical strength and the like of a resin molded body, a method for producing the same, a fiber reinforced resin containing the fibrous reinforcing agent, and a molded body formed of the fiber reinforced resin. .

  A microfibrous resin (or microfiber) having a small fiber diameter is a various additive, for example, a filler for improving the strength of a resin molded body, and a reinforcing agent for improving the strength of a nonwoven sheet. Widely used in paper strength enhancers, filter aids for improving filtration performance, food additives and the like.

  In addition to improving material strength, microfibrous resin improves properties such as concealment, insulation, and weight reduction by utilizing properties such as surface area, uniform dispersibility, entanglement, and powder retention. Are widely put into practical use.

  However, when the microfibrous resin is mixed with the base resin, it is difficult to uniformly disperse the microfibrous resin in the base resin depending on the type of the base resin and / or the microfibrous resin. The effect may not be obtained sufficiently. In particular, since the cellulose resin has a hydrophilic group, the dispersibility of the cellulose microfiber with respect to the resin is low.

  For example, JP-A-9-509694 (Patent Document 1) discloses that in a composition containing a thermoplastic polymer matrix and a cellulose filler, the cellulose filler contains individualized microfibril cellulose. ing. This document describes a polymer latex containing polymer particles as a polymer matrix, and describes that a polymer latex and a water-soluble suspension of microfibril cellulose are mixed with stirring to obtain a water-soluble composition. . Furthermore, this document describes the use of a homogenizer in the microfibrillation of cellulose. However, in this method, the type of resin is limited to a hydrophilic or water-dispersible resin, and the use is remarkably limited. Also, it is not useful in terms of cost.

Japanese Patent Application Laid-Open No. 2008-179922 (Patent Document 2) describes a fibrillated fiber obtained by dividing a composite fiber composed of a plurality of phase-separated resins by a beating process. It is disclosed that fibrillated fibers have a high dispersibility in water. However, Patent Document 2 does not disclose dispersibility and reinforcement of the fibrillated fiber with respect to the matrix resin.
JP-T-9-509694 (Claims 1, 6, page 8, lines 7-9) JP 2008-179922 A (Claim 1, paragraph numbers [0071] [0075] [0076])

  Accordingly, an object of the present invention is to provide a fibrous reinforcing agent that can greatly improve the dispersibility in the matrix resin or the reinforcing property of the matrix resin, even when a hydrophobic matrix resin or the like is used. It is another object of the present invention to provide a method for efficiently and efficiently manufacturing.

  Another object of the present invention is to provide a fibrous reinforcing agent that can be uniformly dispersed with respect to a wide variety of resins and that can improve the mechanical strength of a resin molded body, and a method for producing the same.

  Still another object of the present invention is to provide a fiber reinforced resin or molded body (resin molded body) in which microfibers are dispersed with high dispersibility in a matrix resin and the mechanical strength is improved.

  As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention use a hydrophobic matrix resin when mechanically shearing a cellulosic fiber and a synthetic resin fiber (B) in a solvent. However, the present inventors have found that a fibrous reinforcing agent (fibrous composition) that can be uniformly dispersed in the matrix resin and can effectively reinforce the matrix resin can be obtained.

  That is, the fibrous reinforcing agent of the present invention is a fibrous reinforcing agent for reinforcing a matrix resin, and mechanically shears the cellulosic fiber (A) and the synthetic resin fiber (B) in a solvent. It is obtained by applying a force, and contains fine fibers of the cellulosic fiber (A) and the synthetic resin fiber (B). The fine fibers of the cellulosic fiber (A) are hydrophobized with a hydrophobizing agent (such as a sizing agent, metal coupling agent, acylating agent, isocyanic acid derivative, fats and oils, wax and / or hydrophobic resin). Non-hydrophobized microfibers may be used.

  The synthetic resin fiber (B) may be a fibrous olefin resin or a fine fibrous olefin resin obtained by beating a fibrous olefin resin. The fibrous reinforcing agent may contain the microfibers of the cellulosic fiber (A) and the microfibers of the synthetic resin fiber (B) in a ratio of 10/90 to 90/10 (solid content weight ratio). . In the fibrous reinforcing agent, the fine fibers of the cellulosic fiber (A) and the synthetic resin fiber (B) have an average fiber length (L) of 0.01 to 1 mm, an average fiber diameter (D) of 0.001 to 1 μm, respectively. And an aspect ratio (L / D) of 100 to 10,000.

  The fibrous reinforcing agent is mechanically sheared in a solvent into a cellulosic fiber (A) and a synthetic resin fiber (B) in a solvent to prepare a suspension. It can manufacture by removing a solvent from. The mechanical shearing process may be a homogenizing process.

  The present invention also includes a fiber reinforced resin containing the fibrous reinforcing agent and a resin molded body formed of the fiber reinforced resin. The fiber reinforced resin may include a fibrous reinforcing agent and a resin of the same type as the resin fiber constituting the synthetic resin fiber (B).

  Since the fibrous reinforcing agent of the present invention mechanically shears the cellulosic fiber and the synthetic resin fiber (B) in a solvent, even when a hydrophobic matrix resin or the like is used, Dispersibility or matrix resin reinforcement is greatly improved. Moreover, in the present invention, such a fibrous reinforcing agent can be produced simply and efficiently. Moreover, the said fiber composition can disperse | distribute uniformly with respect to a wide kind of resin, and can improve the mechanical strength of a resin molding effectively. In addition, when a fibrous reinforcing agent and a matrix resin are combined, the fibrous reinforcing agent (microfibers) is dispersed in the matrix resin with high dispersibility, so that the mechanical strength of the fiber reinforced resin or molded body (resin molded body) is increased. Can be greatly improved.

  The fibrous reinforcing agent (fibrous composition) of the present invention is obtained by allowing a mechanical shearing force to act on a cellulosic fiber (A) and a synthetic resin fiber (B) in a solvent. The fiber (A) and the fiber (B) contain microfibers that are miniaturized.

(Cellulose fiber)
Cellulosic fibers include cellulose fibers derived from higher plants (for example, wood fibers (wood pulp such as conifers and hardwoods), bamboo fibers, sugarcane fibers, seed hair fibers (cotton linters, Bombax cotton, kapok, etc.), gin Leather fibers (eg, hemp, mulberry, mitsumata, etc.), leaf fibers (eg, manila hemp, New Zealand hemp), etc., natural cellulose fibers (pulp fibers, etc.), animal-derived cellulose fibers (eg, squirt cellulose), bacteria-derived Cellulose fibers, chemically synthesized cellulose fibers [organic acid esters such as cellulose acetate (cellulose acetate), cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate; cellulose nitrate, cellulose sulfate, Re Inorganic acid esters such as acid cellulose; mixed acid esters such as cellulose nitrate acetate; hydroxyalkyl cellulose (eg, hydroxyethyl cellulose (HEC), hydroxypropyl cellulose, etc.); carboxyalkyl cellulose (carboxymethyl cellulose (CMC), carboxyethyl cellulose, etc.); alkyl Cellulose (methyl cellulose, ethyl cellulose, etc.); cellulose derivatives such as regenerated cellulose (rayon, cellophane, etc.)] and the like. These cellulosic fibers may be used alone or in combination of two or more.

  In addition, when pulp is used as the cellulosic fiber, the pulp is obtained by a mechanical method (pulverized wood pulp, refiner ground pulp, thermomechanical pulp, semichemical pulp, chemiground pulp, etc.), or chemical. Pulp (kraft pulp, sulfite pulp, etc.) obtained by the method may be used, and beating fibers (beating pulp etc.) subjected to beating (preliminary beating) if necessary. The cellulosic fiber may be a fiber subjected to a conventional refining process, such as a degreasing process (for example, absorbent cotton).

  The average fiber length of the cellulose-based fiber used as a raw material is 0.01 to 5 mm (for example, 0.01 to 3 mm), preferably 0.03 to 4 mm (for example, 0.05 to 2.5 mm), and more preferably 0. 0.06 to 3 mm (particularly 0.1 to 2 mm), and usually about 0.1 to 5 mm. Moreover, the average fiber diameter of raw material cellulose fiber is 0.01-500 micrometers (for example, 0.03-400 micrometers), Preferably it is 0.05-450 micrometers (for example, 0.06-400 micrometers), More preferably, it is 0.1. It is about -300 micrometers (for example, 0.2-250 micrometers).

  In addition, the microfibers of the cellulosic fiber (A) can be hydrophobized by introducing a hydrophobic group by attaching a hydrophobic protecting group to the hydrophilic group (hydroxyl group, etc.) of the hydrophobizing agent [microfibrous cellulose. Compounds (such as sizing agents, metal coupling agents (such as metal alkyl or aryl alkoxides), acylating agents, isocyanate derivatives (such as isocyanates such as alkyl esters and aralkyl esters), and / or microfibrous cellulose Non-hydrophobized microfibers that have not been hydrophobized with a hydrophobic compound (such as fats and oils, wax, hydrophobic resin, etc.) that can be hydrophobized by adhering to or covering at least a part of the surface.

(Synthetic resin fiber (B))
As the synthetic resin fiber (B) used in combination with the cellulosic fiber (A), various resin fibers other than the cellulosic fiber can be used. The resin fiber (B) may be any type of resin fiber that can be obtained by mechanical shearing treatment with the cellulosic fiber (A), and is a microfiber (fibrillated or microfibrillated fiber). It may be a fiber that can be micronized (fibrillated or microfibrillated) by mechanical shearing treatment.

  The synthetic resin constituting the synthetic resin fiber (B) is not particularly limited, and examples thereof include thermosetting resins (phenolic resins, polyurethane resins, polyimide resins, polybenzimidazole resins, etc.), thermoplastic resins, and the like. It is done.

  Examples of thermoplastic resins include polyamide resins, saturated polyester resins, polycarbonate resins, polyphenylene oxide resins, polyphenylene sulfide resins, polyketone resins, olefin resins, acrylic resins, fatty acid vinyl ester resins (polyethylene resins). And poly (fatty acid vinyl esters) such as vinyl acetate and vinyl propionate; copolymers of fatty acid vinyl esters and other copolymerizable monomers), vinyl resins and the like. Of these thermoplastic resins, polyamide resins, saturated polyester resins, polyphenylene oxide resins, polyphenylene sulfide resins, olefin resins, acrylic resins, vinyl resins, and the like are preferable.

  Examples of polyamide resins include aliphatic polyamides such as polyamide 46, polyamide 5, polyamide 6, polyamide 66, polyamide 610, polyamide 612, polyamide 11, polyamide 12, polyamide 6/66, polyamide 6/11; alicyclic polyamide; Examples thereof include aromatic polyamides such as polyamide 6T, polyamide 9T, and polyamide MXD; and copolyamides formed of at least two different polyamide-forming components among these polyamides. The polyamide-based resin includes a polyamide elastomer.

Saturated polyester resins include aromatic polyesters (polyesters containing terephthalic acid units, for example, polyalkylene terephthalates such as poly _C2-4 alkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate; polyesters containing naphthalene acid units such as, for example, Polypolyalkylene naphthalates such as poly _C2-4 alkylene naphthalates such as polyethylene terephthalate); Aliphatic polyesters (polyesters containing adipic acid units, such as polyalkylene adipates such as polyethylene adipate and polybutylene adipate; polylactic acid etc.) , Polyarylate, liquid crystalline polyester, and the like. These polyesters usually have crystallinity. The crystalline polyester may be modified with a dicarboxylic acid component and / or a glycol component other than the constituent components. The polyester-based resin also includes a polyester elastomer.

  Examples of the polyphenylene oxide resin include poly (2,5-dimethyl-1,4-phenylene) oxide, poly (2,6-dimethyl-1,4-phenylene) oxide, and poly (2-methyl-6-ethyl-1). , 4-phenylene) oxide, poly (2,6-di-n-propyl-1,4-phenylene) oxide, homopolymers such as poly (2-methyl-6-chloroethyl-1,4-phenylene) oxide, Examples thereof include a modified polyphenylene oxide copolymer based on these homopolymers, a modified graft copolymer in which a styrene polymer is grafted onto polyphenylene oxide or a copolymer thereof.

  Examples of the polyphenylene sulfide resin include polyphenylene sulfide, polyphenylene sulfide ketone, polybiphenylene sulfide, and polyphenylene sulfide sulfone.

Olefin resins include olefin monomer homopolymers, olefin monomer copolymers, and copolymers of olefin monomers and other copolymerizable monomers. . Examples of the olefin monomer include chain olefins [alpha-C _2-20 olefins such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 1-octene ( Preferably α-C _2-10 olefins, more preferably α-C _2-4 olefins)], cyclic olefins [eg, cycloalkenes such as cyclopentene (C _4-10 cycloalkenes etc.); cyclo such as cyclopentadiene An alkadiene (such as C _4-10 cycloalkadiene); a bicycloalkene or bicycloalkadiene such as norbornene or norbornadiene (such as C _8-20 bicycloalkene or bicycloalkadiene); a tricyclo such as dihydrodicyclopentadiene or dicyclopentadiene Alkene or Trisik Alkadiene _{(C 10-25} tricycloalkyl alkene or tri cycloalkadiene etc.), etc.] and the like. These olefinic monomers can be used alone or in combination of two or more. Of the olefin monomers, chain olefins such as α-C _2-4 olefins such as ethylene and propylene are preferable.

  Other copolymerizable monomers include, for example, fatty acid vinyl esters such as vinyl acetate and vinyl propionate; (meth) acrylic monomers such as (meth) acrylic acid, alkyl (meth) acrylate, and glycidyl (meth) acrylate. Unsaturated dicarboxylic acids such as maleic acid, fumaric acid and maleic anhydride, or anhydrides thereof; vinyl esters of carboxylic acids (eg, vinyl acetate, vinyl propionate, etc.)]; cyclic olefins such as norbornene and cyclopentadiene And dienes such as butadiene and isoprene. These copolymerizable monomers can be used alone or in combination of two or more.

Specific examples of the olefin resin include ternary copolymers such as polyethylene (low density, medium density, high density or linear low density polyethylene), polypropylene, ethylene-propylene copolymer, ethylene-propylene-butene-1. Examples thereof include copolymers of chain olefins such as polymers (particularly α-C _2-4 olefins). Moreover, as a specific example of the copolymer of an olefin type monomer and another copolymerizable monomer, for example, chain olefins (particularly, α-C _2-4 olefins such as ethylene and propylene) and Copolymer with fatty acid vinyl ester monomer (for example, ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, etc.); Copolymerization of chain olefins with (meth) acrylic monomers Copolymers [Copolymers of chain olefins (particularly α-C _2-4 olefins) and (meth) acrylic acid (for example, ethylene- (meth) acrylic acid copolymer, propylene- (meth) acrylic acid copolymer) coalescence, ionomers, etc.); (copolymer of particularly alpha-C _2-4 olefin) and alkyl (meth) acrylate (e.g., ethylene - alkyl (meth) chain olefins acrylate copolymer Etc.); etc.]; copolymer chain olefins (especially alpha-C _2-4 olefins) and dienes (e.g., ethylene - butadiene copolymer), epoxy-modified polyolefins (e.g., ethylene - glycidyl ( Modifications such as (meth) acrylate copolymers), carboxy-modified polyolefins (eg, ethylene-maleic anhydride copolymers), epoxies and carboxy-modified polyolefins (eg, ethylene- (meth) acrylic acid-maleic anhydride copolymers) Polyolefins; olefin elastomers (ethylene propylene rubber, etc.) and the like. Olefin resins can be used alone or in combination of two or more.

Examples of the acrylic resin include (meth) acrylic acid, (meth) acrylic acid ester [methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, ( (Meth) acrylic acid C _1-10 alkyl esters such as 2-ethylhexyl acrylate; (meth) hydroxyalkyl (meth) acrylates such as hydroxyethyl acrylate; (meth) acrylic acid glycidyl esters and the like], Examples include homopolymers or copolymers of acrylic monomers such as acrylonitrile; copolymers of acrylic monomers with other monomers, and the like.

  Examples of the acrylic homopolymer or copolymer include poly (meth) acrylic acid ester, acrylic acid ester-methacrylic acid ester copolymer, and polyacrylonitrile. Copolymers of acrylic monomers with other monomers include (meth) acrylic acid ester-styrene copolymers, (meth) acrylic acid-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene. Examples thereof include copolymers and acrylonitrile-styrene- (meth) acrylic acid ester copolymers.

  Examples of vinyl resins include vinyl chloride resins [vinyl chloride monomer homopolymers (polyvinyl chloride resins, etc.), copolymers of vinyl chloride monomers and other monomers (vinyl chloride-vinyl acetate copolymer). Vinyl chloride- (meth) acrylic acid ester copolymers, etc.)], vinyl alcohol resins (homopolymers of vinyl alcohol monomers such as polyvinyl alcohol, vinyl alcohol monomers such as ethylene-vinyl alcohol copolymer) Copolymers with other monomers), polyvinyl acetal resins such as polyvinyl formal, and the like. These vinyl resins may be used alone or in combination of two or more.

  As the synthetic resin fiber (B), one type of synthetic resin fiber may be used, or two or more types of synthetic resin fibers may be combined. The synthetic resin fiber (B) may be a composite fiber in which two or more kinds of resin fibers are combined (for example, a composite fiber composed of a plurality of phase-separated resins). You may use the fiber (divided fiber) obtained by beating processing. In the split fiber, the phase of each resin is split by the beating process of the fiber. For details of the split fibers, reference can be made to, for example, JP-A-2008-179922.

  The resin constituting the composite fiber is not particularly limited and may be a thermosetting resin, but is usually a thermoplastic resin (olefin resin, acrylic resin, vinyl resin, polyester resin, polyamide resin). , Polycarbonate resin, etc.) are often used. Of these resins, olefin resins, vinyl resins, polyester resins, polyamide resins and the like are preferable. As these resin, each resin illustrated in the term of the thermoplastic resin which comprises the said synthetic resin fiber (B) can be used.

  Among the olefin resins, polyethylene and polypropylene are preferable, and among the polyester resins, aromatic polyester (polyester containing a terephthalic acid unit, for example, polyalkylene terephthalate such as polyethylene terephthalate and polybutylene terephthalate); aliphatic polyester (Polyesters containing adipic acid units, for example, polyalkylene adipates such as polyethylene adipate and polybutylene adipate; polylactic acid, etc.) are preferred. Further, preferred polyamide resins include aliphatic polyamide resins such as polyamide 6, polyamide 66, polyamide 610, polyamide 612, polyamide 11, and polyamide 12. As the vinyl resin, vinyl chloride resin and the like are preferable.

  Of the resins constituting these composite fibers, olefin-based resins, vinyl-based resins, polyester-based resins, and polyamide-based resins, particularly olefin-based resins are preferable. The composite fiber is usually composed of two kinds of phase-separated resins.

  As a preferable combination, (a) a combination of a plurality of phase-separable olefin resins (for example, a combination of different olefin resins such as a combination of a polyethylene resin and a polypropylene resin, a different polypropylene resin capable of phase separation) (B) a combination of an olefin resin and at least one selected from a vinyl ester resin, a polyester resin and a polyamide resin, and (c) a combination of a vinyl resin and a polyamide resin. Etc.

  In particular, a combination of a polypropylene resin and another resin (such as a resin other than a polypropylene resin) that can be phase-separated from the polypropylene resin is preferable. The ratio (weight ratio) between the polypropylene resin and other phase separable resins (polyethylene resin, vinyl ester resin, polyester resin, polyamide resin, etc.) is, for example, polypropylene resin / phase separable Other resin = 10/90 to 90/10, preferably 30/70 to 85/15, more preferably about 50/50 to 80/20.

  The cross-sectional structure (transverse cross-sectional structure) of the composite fiber is not particularly limited. For example, a radial array type (for example, a shape in which one component and the other component of a plurality of resins are arranged radially, one component) Are arranged in a thin layer and radially, the other component is radially divided by this thin layer component, the form in which one component and the other component are radially divided by an adhesive layer, etc.), A side-by-side type (or a parallel type or a multi-layered type), a sea-island type, a core-sheath type, or the like may be used. The composite fiber may be solid or hollow.

  Moreover, the cross-sectional shape (transverse cross-sectional shape) of the composite fiber is not particularly limited, and may be, for example, a circle, a polygon (triangle, quadrangle, etc.).

  The average fiber diameter of the composite fiber is not particularly limited, and may be about 0.1 to 50 μm, preferably 0.5 to 40 μm, and more preferably about 1 to 30 μm. The average fiber length of the composite fiber may be, for example, about 0.1 to 10 mm, preferably about 0.5 to 8 mm, and more preferably about 0.8 to 6 mm.

  The composite fiber may contain other fibers [natural fibers (such as cellulose fibers), synthetic fibers, semi-synthetic fibers (such as acetate)] as necessary, and additives (eg, colorants, antistatic agents). Agents, surfactants, fragrances, deodorizers, antibacterial agents, and the like).

  When the split fiber obtained by beating the composite fiber is used as the fiber (B), the beating process of the composite fiber is performed by a conventional beating process method, for example, at least one processing method selected from a refiner process and a homogenization process. be able to. The details of such beating processing can be referred to Japanese Patent Laid-Open No. 2008-179922.

  The average fiber diameter of the split fibers (fibrillated fibers) obtained by beating the composite fiber can be selected from a wide range of 0.01 to 30 μm, for example, 0.05 to 25 μm, preferably 0.1 to 20 μm, More preferably, it may be about 0.3 to 20 μm. Further, the average fiber length of the fibrillated fibers can be selected from a wide range of 0.1 to 5 mm, for example, 0.1 to 4 mm, preferably 0.3 to 4 mm, more preferably about 0.3 to 3 mm. There may be.

  The ratio of the synthetic resin fiber (B) is, for example, 1 to 1000 parts by weight, preferably 10 to 500 parts by weight, and more preferably 20 to 200 parts by weight in terms of solid content with respect to 100 parts by weight of the cellulose fiber (A). It may be about 50 parts by weight, particularly about 50 to 150 parts by weight. Such a ratio also corresponds to the ratio of the fine fibers of the resin fiber (B) to the fine fibers of the cellulosic fiber (A) after the mechanical shearing treatment.

  The average fiber length (L) of the cellulosic fiber (A) and the synthetic resin fiber (B) is 0.01 to 1 mm (for example, 0.02 to 0.7 mm), preferably 0.03 to 0.9 mm. More preferably, it may be about 0.05 to 0.8 mm (particularly 0.06 to 0.7 mm). The average fiber diameter (D) of the microfibers is 0.001 to 1 μm, preferably 0.005 to 0.8 μm, more preferably 0.01 to 0.6 μm (particularly 0.1 to 0.4 μm). It may be a degree. The aspect ratio (L / D) of the microfiber may be about 100 to 10000, preferably about 200 to 8000, more preferably about 400 to 6000 (particularly 600 to 4000). The average fiber length and average fiber diameter of the microfibers are the same as or less than the average fiber length and average fiber diameter of the raw fiber before mechanically shearing.

  The fibrous reinforcing agent is an indefinite shape (pellet shape, powdery shape, etc.) micro resin (indefinite shape micro resin obtained by applying mechanical shearing force to an indefinite shape resin having an average diameter of 0.01 to 50 mm, etc. ) May not be substantially contained.

(Method for producing fibrous reinforcing agent)
The fibrous reinforcing agent is obtained by mechanically shearing cellulosic fibers (A) and synthetic resin fibers (B) in a solvent to prepare a suspension, and removing the solvent from the suspension. Can be manufactured.

The solvent is not particularly limited as long as it does not cause chemical or physical damage to the raw resin fibers. For example, water, organic solvents [alcohols (C _1-4 alkanol such as methanol, ethanol, 2-propanol, isopropanol, etc. ), Ethers (di-C _1-4 alkyl ethers such as diethyl ether and diisopropyl ether, cyclic ethers such as tetrahydrofuran (cyclic C _4-6 ethers)), ketones (dialkyl ketones such as acetone, methyl ethyl ketone, and methyl butyl ketone) (Di-C _1-5 alkyl ketone etc.); cycloalkanones such as cyclohexanone (C _4-10 cycloalkanone etc.)), aromatic hydrocarbons (toluene, xylene etc.), halogenated hydrocarbons (methyl chloride, fluorine Etc.) It is.

These solvents may be used alone or in combination of two or more. Of these solvents, water is preferable from the viewpoint of productivity and cost. If necessary, a mixed solvent of water and an aqueous organic solvent (C _1-4 alkanol, acetone, etc.) may be used.

  The cellulosic fiber (A) and the synthetic resin fiber (B) to be subjected to the mechanical shearing treatment may be in a state of coexisting at least in the solvent. Prior to the mechanical shearing treatment, the cellulosic fiber (A) and the synthetic resin fiber (B) (B) may be dispersed in a solvent. Dispersion may be performed using, for example, a conventional disperser (such as an ultrasonic disperser, a homodisper, or a three-one motor). The disperser may include mechanical stirring means (such as a stirring bar and a stirring bar).

  The concentration of the cellulosic fiber (A) and the synthetic resin fiber (B) in the solvent is 0.01 to 50% by weight, preferably 0.05 to 40% by weight, and more preferably 0.0% by weight as the total amount of both fibers. It may be about 1 to 30% by weight.

  The mechanical shearing force is not particularly limited as long as the mechanical resin can be applied to make the raw resin finer. For example, mechanical shearing force such as beating treatment (homogenization treatment, refiner treatment, etc.), ultrasonic waves, etc. A treatment may be applied, and it is particularly preferable to apply a mechanical shearing force by a beating process such as a homogenization process. These mechanical shearing forces may be used alone or in combination of two or more. If necessary, a conventional preliminary beating process may be performed prior to the mechanical shearing force.

  In the homogenization treatment, a conventional homogenizer (for example, a homogenizer, particularly, a high-pressure homogenizer) can be used.

  The high-pressure homogenizer has a narrow channel (for example, an orifice (such as a small-diameter orifice)) inside. The high-pressure homogenizer applies pressure by passing the dispersion liquid through the narrow channel, and wall surfaces such as the inner wall of the container. It is also possible to use a device of a type that applies a shearing stress or a cutting action by being caused to collide with.

  In such a high-pressure homogenizer, the pressure applied by passing through a narrow flow path (or the pressure (or processing pressure) fed to the high-pressure homogenizer) is, for example, 30 to 100 MPa, preferably 35 to 80 MPa, and more preferably May be about 40 to 60 MPa (for example, 45 to 55 MPa).

  In addition, by repeatedly performing the passage of the narrow channel and the collision with the wall surface, it is possible to appropriately adjust the degree of miniaturization of the raw resin fibers and the homogenization of the dispersion. The number of repetitions (or the number of treatments (or the number of passes)) of the passage of the narrow channel and the collision with the wall surface is 5 to 30 times, preferably 7 to 25 times, more preferably 10 to 20 times (for example, 12-18 times).

  For details of the miniaturization using such a high-pressure homogenizer, reference can be made to, for example, Japanese Patent Publication No. 60-19921.

  In the suspension obtained by such a method, the cellulosic fibers (A) and the synthetic resin fibers (B) are highly miniaturized, and the microfibers of the fibers (A) and (B) are complicated with each other. The microfibers are uniformly dispersed in the solvent to form a stable suspension (or slurry suspension).

  The suspension may contain additives as necessary. Examples of additives include stabilizers [antioxidants (such as hindered phenolic antioxidants), shrinkage inhibitors, antistatic agents, ultraviolet absorbers, heat stabilizers, weathering stabilizers, etc.], lubricants, mold release Agents, lubricants, impact modifiers, colorants (such as dyes and pigments), plasticizers, flame retardants, antibacterial agents, antiseptics, fungicides, insecticides, deodorants and the like.

Examples of the method for removing the solvent include conventional liquid removal treatment (for example, filtration, pressing, centrifugation, etc.), drying treatment, and the like. These treatments may be used in combination as appropriate, but at least drying treatment is preferable. For example, the solution may be drained by filtration and then dried. Moreover, you may substitute (solvent substitution) the kind of solvent of the said suspension with manufacture of a fibrous reinforcement. In the case of solvent replacement, for example, after removing the aqueous solvent, the microfibers are dispersed in an organic solvent (the organic solvent exemplified above, for example, C _1-4 alkanol, acetone, etc.), and further subjected to liquid removal treatment. Also good. Moreover, you may dry as needed after the liquid removal of an aqueous solvent and / or the liquid removal of an organic solvent.

  The drying temperature can be selected from a wide range of about 20 to 300 ° C., but is lower than the glass transition temperature (Tg) of the plurality of microresins, for example, 25 to 250 ° C., preferably 28 to 200 ° C., more preferably 30. It may be about ~ 150 ° C (particularly 40 to 130 ° C). When dried at such a temperature, the fine fibers are not bonded by heat, and the effect of miniaturization is not impaired.

  For drying, a known drier, for example, a Nauter drier, a shelf drier, a rotary mixer with a heating jacket, or the like can be used as necessary.

  The fibrous reinforcing agent may be subjected to a pulverization process, a pelletizing process, or the like, if necessary. For the pulverization, a known pulverizer such as a sample mill, a hammer mill, or a cutter mill may be used. Moreover, you may use a well-known pelletizing apparatus, for example, a pelletizer etc., for a pelletizing process.

  The fibrous reinforcing agent may be used as a resin composition in combination with another resin. In particular, a fibrous reinforcing agent may be used as a master batch, mixed (diluted) with another resin (or matrix resin), and used as a fiber reinforced resin (or fiber reinforced resin composition). In addition, fibrous resin may be sufficient as other resin, and granular resin or pellet-shaped resin may be sufficient as it. The other resin may be in a solid state or a molten state. By using the fiber composition in which the fine fibers of the cellulosic fiber (A) and the synthetic resin fiber (B) are uniformly dispersed, even if the matrix resin is hydrophobic, it can be uniformly dispersed in the matrix resin. Resin can be effectively reinforced. Therefore, the fibrous reinforcing agent can be applied to a wide variety of matrix resins and is useful as a reinforcing agent or reinforcing agent for various matrix resins.

  Examples of the other resin include the resins exemplified in the section of the fiber (B), and the fiber (B) and a homogeneous resin may be formed, or a polymer alloy may be formed. The other resin may be a different type of resin from the fiber constituting the fiber (B), but from the viewpoint of kneadability, the same kind of resin as the at least one resin fiber constituting the fiber (B) is used. Is preferred. In the case of different types of resins, it is preferable to knead using a compatibilizer.

  Examples of the compatibilizing agent include thermoplastic resins modified with a compound having a polar group. Examples of the thermoplastic resin include polyolefin resins (polyethylene, polypropylene, ethylene-propylene copolymers, propylene-butene copolymers, etc.), polyamide resins (polyamide 6, polyamide 12, etc.), and cyclic hydrocarbon resins (cyclic). Olefin copolymer), polystyrene resin (polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-conjugated diene-styrene copolymer (ABS resin, etc.), styrene-conjugated diene copolymer and / or hydrogen thereof. Additive resins (SBS, SIS, SIBS, SEBS, SEPS, SEEPS, SBBS, etc.), styrenic thermoplastic elastomers [styrene-conjugated diene copolymers and / or mixtures containing hydrogenated resins or partially crosslinked products thereof (for example, Styrene A role diene copolymer and / or a hydrogenated resin, olefin resin or the like, and / or a mixture obtained by blending an oil), etc.], etc.} and the like. Of these, polyolefin resins, polyamide resins, polystyrene resins and the like are preferable.

  In the compound having a polar group as a modifier for modifying these thermoplastic resins, examples of the polar group include a carboxyl group, a carbonyl group (an ester group, an amide group, an acid is a ride group, etc.), an acid anhydride, and the like. Group, amino group, hydroxyl group, glycidyl group, oxazolyl group and the like. These polar groups may be used alone or in combination of two or more. Preferred polar groups are a carboxyl group, an acid anhydride group, a glycidyl group, and the like.

  Specific examples of the compound having a polar group include compounds having a carboxyl group (monocarboxylic acids such as (meth) acrylic acid, dicarboxylic acids such as maleic acid and fumaric acid and anhydrides thereof), and unsaturated glycidyl compounds. And / or derivatives thereof (glycidyl (meth) acrylate, allyl glycidyl ether, vinyl glycidyl ether, etc.). Of these, compounds having a carboxyl group (particularly maleic anhydride (MAH) and the like), unsaturated glycidyl compounds and / or derivatives thereof (particularly glycidyl methacrylate (GMA) and the like) are preferred. These compatibilizers may be used alone or in combination of two or more.

  The ratio (weight ratio) between the fibrous reinforcing agent and the other resin is not particularly limited. For example, the fibrous reinforcing agent / other resin = 0.1 / 99.9 to 99/1, preferably 0.8. 2 / 99.8 to 90/10, more preferably 0.3 / 99.7 to 80/20 (for example, 0.4 / 99.6 to 70/30), particularly 0.5 / 99.5 About 60/40 (for example, 1/99 to 50/50) may be sufficient.

  In addition, the ratio of the microfibers of the cellulosic fiber (A) in the fibrous reinforcing agent is 10 to 80% by weight, preferably 20 to 70% by weight, more preferably 25 to 60% with respect to the whole fibrous reinforcing agent. It may be about wt%.

  The molded body of the present invention is formed of the fiber reinforced resin. Such a molded body can be obtained by melt-kneading a fiber reinforced resin and molding it by a conventional molding method (extrusion molding, injection molding, compression molding, etc.).

  The melt-kneading can be performed using a conventional method, that is, a conventional melt-kneader, for example, a single screw or vent type twin screw extruder. Prior to melt kneading, a conventional method, for example, a mixer (such as a tumbler, V-type blender, Henschel mixer, Nauta mixer, ribbon mixer, mechanochemical apparatus, extrusion mixer, etc.) Ingredients (such as the additives mentioned above) may be premixed. The melt kneading temperature may be, for example, about 70 to 300 ° C, preferably about 80 to 280 ° C, and more preferably about 85 to 260 ° C.

  Furthermore, the obtained molded body has high strength because the microfibers are sufficiently dispersed in the molded body (resin fibers added to the microfibers or the other resins described above).

  Since the molded body has high strength, space-related products (artificial satellites (artificial satellite body, parabolic antenna, solar cell frame, etc.), space shuttle (airframe, wing, remote control rod, luggage compartment door, etc.), etc.) Useful for aircraft parts (airframe, main wing, tail wing, rudder, etc.), automotive parts (body, hood, door, drive shaft, etc.), sports equipment (golf shaft, tennis racket frame, etc.), leisure equipment (fishing rod, etc.) is there. Further, if necessary, it can be spun and can be used for clothes and the like.

  In the fibrous reinforcing agent of the present invention, fine fibers of cellulosic fibers and synthetic resin fibers are uniformly dispersed, and the dispersibility to the resin is high. Therefore, it is useful as a resin reinforcing agent to be added to the resin to reinforce it. Moreover, since the obtained fiber reinforced resin and molded object have high intensity | strength, they can be used for space related goods (artificial satellite, space shuttle, etc.), aircraft parts, automobile parts, sports goods, leisure goods, etc.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
20 L of water was added to 100 g of commercially available kraft pulp (average fiber length 3 mm, average fiber diameter 12 μm) and fibrous polypropylene resin (EDC810 manufactured by Chisso Polypro), and stirred well. The obtained dispersion was charged into a homogenizer (15M-8TA, high pressure homogenizer manufactured by GAULIN) at room temperature and passed 15 times under a pressure of 44.1 MPa to obtain a slurry suspension. The slurry suspension was drained with a centrifugal drainer, and then solvent substitution was performed using 100 L of isopropyl alcohol. Further, after draining, it was dried to obtain a cotton-like thermoplastic fiber / microfibrillated (MF) cellulose composite.

  The obtained cotton-like composite and a fibrous polypropylene resin similar to the above were mixed so that the ratio of MF-modified cellulose fibers was 40% by weight, and a twin-screw extruder (Nikko Corporation, TEX30α). ) At 190 ° C. and pelletized with a pelletizer. When the surface of the pellet was observed with a scanning electron microscope, the dispersion state was uniform.

Comparative Example 1
Except for preparing a slurry suspension without using a commercially available kraft pulp, the same operation as in Example 1 was performed to obtain a MF-modified PP fiber in place of the cotton-like composite.

  The obtained MF-ized PP fiber and a commercially available kraft pulp (average fiber length 3 mm, average fiber diameter 12 μm) were mixed so that the proportion of kraft pulp was 40% by weight, and a twin-screw extruder (Nikko ( Co., Ltd., TEX30α) was kneaded at 190 ° C. and then pelletized with a pelletizer.

Comparative Example 2
20 L of water was added to 100 g of commercially available kraft pulp (average fiber length: 3 mm, average fiber diameter: 12 μm), and stirred well. The obtained dispersion was charged in a homogenizer (15M-8TA, high pressure homogenizer manufactured by GAULIN) at room temperature and passed 15 times under a pressure of 44.1 MPa to form a microfibrillated (MF) cellulose slurry. A suspension was obtained.

  To this suspension, 100 g of fibrous polypropylene resin (EDC810 manufactured by Chisso Polypro) was mixed and stirred for 3 minutes with a stirrer (UT1305 manufactured by Makita). The obtained mixture was subjected to a liquid removal treatment with a centrifugal liquid remover, and then subjected to solvent replacement using 100 L of isopropyl alcohol. The solution was further drained and dried.

  The obtained dried product and a fibrous polypropylene resin similar to the above were mixed so that the ratio of MF-modified cellulose fibers was 40% by weight, and the mixture was mixed into a twin screw extruder (Nikko Corporation, TEX30α). The mixture was kneaded at 190 ° C. and pelletized with a pelletizer.

Using the pellets obtained in Examples and Comparative Examples, the following physical property tests were performed, and the molded pieces were visually evaluated. The results are shown in Table 1.
(1) Density Density (g / cm ³ ) was measured according to ISO 1183.
(2) Flexural strength and flexural modulus The flexural strength (MPa) and flexural modulus (MPa) were measured according to ISO178.
(3) Charpy impact strength Charpy impact strength (kJ / m ² ) was measured using a notched specimen at 23 ° C. in accordance with ISO 179 / 1eA.
(4) Deflection temperature under load According to ISO75, the deflection temperature under load (° C.) was measured under the conditions of 1.80 MPa and 0.45 MPa.

  As is clear from Table 1, in the examples, the flexural modulus and the deflection temperature under load were significantly improved as compared with the comparative examples.

FIG. 1 is a 1000 × magnification scanning electron micrograph of the surface of the sample obtained in Example 1.

Claims (9)

  A fibrous reinforcing agent for reinforcing a matrix resin, which is obtained by applying a mechanical shearing force to a cellulose-based fiber (A) and a synthetic resin fiber (B) in a solvent, and the cellulose A fibrous reinforcing agent comprising microfibers of a system fiber (A) and a synthetic resin fiber (B).   The fibrous reinforcing agent according to claim 1, wherein the synthetic resin fiber (B) is a fibrous olefin resin or a fine fibrous olefin resin obtained by beating a fibrous olefin resin.   The fibrous form of Claim 1 or 2 which contains the microfiber of a cellulosic fiber (A) and the microfiber of a synthetic resin fiber (B) in the ratio (solid content weight ratio) of 10 / 90-90 / 10. Reinforcing agent.   The fine fibers of the cellulosic fiber (A) and the fine fibers of the synthetic resin fiber (B) have an average fiber length (L) of 0.01 to 1 mm, an average fiber diameter (D) of 0.001 to 1 μm, and an aspect ratio, respectively. The fibrous reinforcing agent according to any one of claims 1 to 3, which has (L / D) of 100 to 10,000.   The cellulosic fiber (A) and the synthetic resin fiber (B) are mechanically sheared in a solvent to prepare a suspension. The solvent is removed from the suspension, and the cellulosic fiber (A And a fibrous reinforcing agent containing fine fibers of the synthetic resin fiber (B).   The production method according to claim 5, wherein the mechanical shearing treatment is a homogenization treatment.   A fiber reinforced resin containing the fibrous reinforcing agent according to any one of claims 1 to 4.   The fiber reinforced resin according to claim 7, comprising a fibrous reinforcing agent and a resin of the same type as the resin fiber constituting the synthetic resin fiber (B).   A resin molded body formed of the fiber reinforced resin according to claim 7 or 8.