JP6528997B2 - Method for producing cellulose fiber for resin reinforcement, method for producing cellulose fiber for resin reinforcement, method for producing resin composition and method for producing resin molded article - Google Patents

Description

The present invention relates to a process for producing a resin reinforcing cellulose fibers which can improve the strength of the cellulose fiber composite resin molded article, a method of manufacturing cellulose fiber resin reinforced relates to a method of manufacturing a production method and a resin molded article of the resin composition .

Heretofore, fibrous additives such as glass fibers, carbon fibers, aramid fibers, and cellulose fibers have been used for the purpose of improving the strength of resin molded articles. Among them, cellulose fibers have features such as low density, high elastic modulus, and low linear thermal expansion coefficient. In addition, since it is "carbon neutral" and a sustainable resource, it is expected to be a material contributing to the reduction of environmental impact. However, the cellulose fiber is hydrophilic, the resin is hydrophobic, and the adhesion between the cellulose fiber and the resin is bad. The strength of the cellulose fiber is not sufficiently reflected in the composite. In addition, since it is difficult to uniformly disperse cellulose fibers in a resin, there may be a case where a reinforcing effect due to entanglement of fibers is not sufficiently obtained.

As a means to improve the strength of the cellulose fiber composite resin, various additives capable of improving the dispersibility of the cellulose fiber in the resin have been proposed.

For example, Patent Document 1 discloses a first primary compound having an aliphatic hydrocarbon group having 10 to 25 carbon atoms substituted with an epoxy group while stirring a pulverized pulp containing an aqueous solution of a primary amine compound. A first step of applying a mixed solution containing a surfactant and a nitrous acid compound to a pulverized pulp, and a hydrophobic group having an aliphatic hydrocarbon group and ethylene while stirring the pulverized pulp coated with the mixed solution. A second step of adhering an aqueous dispersion containing a second surfactant having a hydrophilic group having an oxide group and a polyisobutylene having a weight average molecular weight of 15,000 to 300,000 on a pulverized pulp, and attaching the aqueous dispersion There is disclosed a method for producing a pulp composite reinforced resin, comprising a third step of kneading and compositing crushed pulp and molten polypropylene with each other. The effect of improving the mechanical strength of the molded product were unsatisfactory.

In Patent Document 2, an organic additive having one or more functional groups functioning as a Lewis acid in the molecule and one or more characteristic groups capable of developing a hydrogen bond in the molecule is provided in the composite material of bamboo and matrix resin. A method of use is disclosed. Examples of the organic additive include low molecular weight compounds such as asparagine, aspartic acid and glutamine. However, the cellulose fibers can not be sufficiently dispersed in the resin, and the effect of improving the mechanical strength of the molded article of the resin composition is insufficient.

In Patent Document 3, the cellulose is directly refined in a vinyl resin without using water or an organic solvent, so that it is not necessary to remove the solvent, modify the cellulose, etc., and directly combine with other dilution resins. SUMMARY OF THE INVENTION A method of providing a cellulose nanofiber and a masterbatch containing cellulose nanofibers that can be converted is disclosed. However, the effect of improving the mechanical strength of the molded article of the resin composition is insufficient.

Patent No. 4869449 JP, 2009-173714, A JP, 2013-116928, A

The present invention is a cellulose fiber composite resin process for producing a molded article strength dramatically resin reinforcing cellulose fibers which can be improved in a process for producing cellulose fiber resin reinforced, method for producing a resin composition and a resin molded article It is an object of the present invention to provide a manufacturing method of

As a result of repeated studies to solve the above problems, the present inventors polymerize vinyl monomers having cationicity and nonionic (meth) acrylic esters when mixing cellulose fiber and resin. By using a cellulose fiber which is a polymer having a structural unit to be formed and which is modified with a cationic polymer having a specific range of cation equivalent as a cellulose fiber for resin reinforcement, the strength of a molded article of cellulose fiber composite resin is It was found to be excellent.

That is, the means of the present invention for solving the above-mentioned problems is
It is manufactured by mixing the following cationic polymer with <1> cellulose fiber,
The cationic polymer is
Structural units (a) formed by polymerization of at least one selected from cationic vinyl monomers, and
Structural unit (b) formed by polymerization of at least one selected from nonionic (meth) acrylic esters
Have the structure of
Cation Ri equivalent of 0.05~1meq / g Der,
A method for producing a cellulose fiber for resin reinforcement, wherein the weight ratio is cationic polymer / cellulose fiber = 9 to 50/91 to 50 ;
<2> The cellulose fiber for resin reinforcement according to <1>, wherein the cationic polymer further has a structure of a structural unit (c) formed by polymerization of at least one selected from (meth) acrylamides. Manufacturing method,
The manufacturing method of the cellulose fiber for resin reinforcements of said <2> whose <3> (meth) acrylamides are at least 1 type chosen from (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, and acryloyl morpholine,
The manufacturing method of the cellulose fiber for resin reinforcement any one of said <1>-<3> by which the hydroxyl group of cellulose is denatured by at least 1 type of etherification, esterification, silylation of <4> cellulose fiber,
The manufacturing method of the cellulose fiber for resin reinforcement in any one of said <1>-<4> which is a cellulose fiber for <5> thermoplastic resin reinforcement,
<6> Thermoplastic resin and method for producing resin composition containing cellulose fiber for resin reinforcement obtained by the method for producing cellulose fiber for resin reinforcement of <5>,
The manufacturing method of the resin molding obtained by shape | molding the resin composition obtained from the manufacturing method of the resin composition of <7> said <6> ,
It is.

According to the present invention, by using the cellulose fiber for resin reinforcement of the present invention, the strength of the molded article of the cellulose fiber composite resin can be dramatically improved. The following mechanism of action is considered as the reason.

The cellulose fiber for resin reinforcement in the present invention has a surface coated with a cationic polymer. The cationic polymer has a cationic group capable of electrostatically binding to the carboxyl group of the cellulose surface, and a hydrophobic group excellent in affinity with the resin, and is present at the interface between the cellulose fiber and the resin. Adhesion is improved. Further, since the cationic polymer is a polymer, it can be adsorbed to the cellulose fiber and the resin at a plurality of points, so that the interfacial adhesion can be specifically enhanced. Furthermore, since the hydrophobic group of the cationic polymer shields the hydroxyl group on the cellulose surface, the aggregation of the cellulose fibers due to hydrogen bonding can be suppressed, and the cellulose fibers can be well dispersed in the resin. As a result, the strength of the cellulose fiber can be reflected on the resin to enhance the effect of reinforcing the resin.

Hereinafter, embodiments of the present invention will be described in detail. The following description is an example of the embodiment of the present invention, and the present invention is not limited to the description.

In the present invention, the cellulose fiber for resin reinforcement is obtained by mixing and adsorbing a specific cationic polymer to the cellulose fiber. The cationic polymer is a structural unit (a) formed by polymerization of at least one selected from cationic vinyl monomers, and at least one selected from non-ionic (meth) acrylic esters. It has a structure of the structural unit (b) to be formed, and has a cation equivalent of 0.05 to 1 meq / g.

The structural unit (a) is formed by polymerization of at least one cationic vinyl monomer selected from vinyl monomers having a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium salt. It imparts a positive charge to the cationic polymer and can be electrostatically bonded to anionic groups such as carboxyl groups and sulfone groups scattered on the surface of the cellulose fiber. As a cationic vinyl monomer which can form a structural unit (a), the following are mentioned, for example.

Examples of the vinyl monomer having a primary amino group include vinylamine and allylamine hydrochloride. The structural unit (a) may be formed by polymerization of at least one selected from cationic vinyl monomers, and may be modified after monomer polymerization to obtain a structural unit (a) having a primary amino group. You can also. Specifically, it is formed by polymerizing a vinylamine obtained by hydrolyzing a polymer of N-vinylformamide or N-vinylacetamide in the presence of a basic compound or performing Hofmann rearrangement of an acrylamide polymer. It can be structural unit (a).

Examples of the vinyl monomer having a secondary amino group include diallylamine.

As a vinyl monomer having a tertiary amino group, for example, dialkylaminoalkyl (meth) such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate and diethylaminopropyl (meth) acrylate Acrylates; Dialkylaminoalkyl (meth) acrylamides such as dimethylaminopropyl (meth) acrylamide and diethylaminopropyl (meth) acrylamide, methyldiallylamine, hydrochlorides of vinyl monomers having the above-mentioned tertiary amino group, sulfates, etc. And inorganic acid salts; and formate salts of vinyl monomers having a tertiary amino group, and organic acid salts such as acetates.

As a vinyl monomer which has a quaternary ammonium salt, the vinyl monomer obtained by reaction of the vinyl monomer which has the said tertiary amino group, and a quaternizing agent is mentioned, for example. As the quaternizing agent, alkyl chlorides such as methyl chloride and methyl bromide; aralkyl halides such as benzyl chloride and benzyl bromide; dimethyl sulfate, diethyl sulfate, epichlorohydrin, 3-chloro-2-hydroxypropyl trimethyl Ammonium chloride, glycidyl trimethyl ammonium chloride and the like can be mentioned.

Among these, diallylamine and benzyl chloride quaternary compound of dimethylaminoethyl methacrylate are preferable. These may be used alone or in combination of two or more.

The structural unit (b) is a structure formed by polymerization of at least one nonionic (meth) acrylic ester selected from nonionic (meth) acrylic esters, and the cationic polymer is used as a resin. Can give an affinity for

As nonionic (meth) acrylic esters, specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate Sec-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl Alkyl (meth) acrylates such as (meth) acrylates and stearyl (meth) acrylates; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; Alicyclic alkyl (meth) acrylates such as lohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate; isobornyloxyethyl (meth) acrylate, Alicyclic alkyloxyethyl (meth) acrylates such as dicyclopentanyloxyethyl (meth) acrylate and dicyclopentenyl oxyethyl (meth) acrylate; benzyl (meth) acrylate, benzyloxyethyl (meth) acrylate, phenyl (meth) acrylate 2.) Acrylate, phenoxyethyl (meth) acrylate, polyethylene oxide monomethacrylate, glycidyl methacrylate and the like. Among these, benzyl (meth) acrylate and ethyl (meth) acrylate are preferable. These may be used alone or in combination of two or more.

The mass ratio of the cationic vinyl monomer capable of forming the structural unit (a) and the nonionic (meth) acrylic esters capable of forming the structural unit (b) is 35% of the total polymer. -100 mass% is preferable. When the total mass of the structural unit (a) and the structural unit (b) is less than 35% by mass, the site for electrostatic bonding to cellulose fiber and the site for affinity with the resin are insufficient, so good strength is obtained. It may not be possible.

In the cationic polymer constituting the resin-reinforcing cellulose fiber in the present invention, it is more preferable that the structural unit (c) be contained in addition to the structural unit (a) and the structural unit (b) within a range not impairing the effect. The structural unit (c) is a structural unit formed by polymerizing at least one kind of (meth) acrylamide selected from (meth) acrylamides, and has an affinity to the surface of a cellulose fiber that is hydrophilic, Although not as remarkable as the structural unit (a), it can contribute to the fixation of the cationic polymer on the cellulose fiber surface.

Specifically as (meth) acrylamides, N-substituted (meth) such as (meth) acrylamide, isopropyl (meth) acrylamide, butyl (meth) acrylamide, isobutyl (meth) acrylamide, t-butyl (meth) acrylamide and the like Acrylamide; N, N-disubstituted (meth) acrylamides such as N, N-dimethyl (meth) acrylamide, N, N-diethylacrylamide etc .; N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide etc N-Alkoxymethyl (meth) acrylamide; N-hydroxy such as N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, 3-hydroxypropyl (meth) acrylamide, 4-hydroxybutyl (meth) acrylamide Alkyl (meth) acrylamide; acryloyl morpholine and the like. Among these, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, t-butyl (meth) acrylamide and acryloyl morpholine are preferable. These may be used alone or in combination of two or more.

As for the mass ratio of (meth) acrylamides which can form a structural unit (c), 0-65 mass% of the whole polymer is preferable. If the mass of the structural unit (c) is more than 65% by mass, there is a possibility that the site of electrostatic bonding to cellulose fiber and the site of affinity to the resin may be insufficient, and good strength may not be obtained. .

A cationic vinyl monomer capable of forming a structural unit (a), a nonionic vinyl compound capable of forming a structural unit (b), for the purpose of controlling the glass transition temperature of the cationic polymer and controlling the molecular weight by crosslinking etc. Besides the (meth) acrylic esters and (meth) acrylamides that can form the structural unit (c), the structural unit (d) may be added.

As the monomer (d), styrene, divinylbenzene, acrylonitrile, N-vinylpyrrolidone, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl laurate, vinyl cyclohexanecarboxylate, vinyl pivalate, maleic anhydride, Maleic acid monoethyl ester, maleic acid monobutyl ester, fumaric acid, itaconic acid, (meth) acrylic acid, t-butylacrylamidosulfonic acid, 1-octene, 1-decene, vinylcyclohexene, trimethoxysilylpropyl methacrylate, etc. Be

The mass ratio of (meth) acrylamides capable of forming the structural unit (d) is 0 to 40% by mass, preferably 0 to 20% by mass, more preferably 0 to 10% by mass, still more preferably 0 based on the whole polymer. And 5% by mass. If the mass of the structural unit (d) is more than 40% by mass, there is a possibility that the site of electrostatic bonding to cellulose fibers and the site of affinity to the resin may be insufficient, and good strength may not be obtained. .

There is no limitation on the method of polymerizing the monomer that forms the structural unit of the above cationic polymer, and for example, conventionally known methods such as solution polymerization, suspension polymerization, emulsion polymerization, and solvent-free bulk polymerization can be used. The reaction mechanism is also not particularly limited, and radical polymerization, anion polymerization, cation polymerization, coordination polymerization and the like can be used.

The cationic equivalent of the cationic polymer means the mass of substance per unit gram of the cationic group introduced to the cationic polymer, and it is necessary to be 0.05 to 1 meq / g. If it is smaller than 0.05 meq / g, the cationic polymer is not sufficiently fixed to the cellulose surface, and sufficient strength can not be obtained. If it is more than 1 meq / g, the hydrophilicity of the cationic polymer becomes too strong, the adhesion to the resin is impaired, and a sufficient strength can not be obtained.

As a means for measuring the cation equivalent of the cationic polymer, a method of using 15 N-NMR or X-ray photoelectron spectroscopy (XPS) for the extract of the cationic polymer can be adopted.

The polymerization initiator is not particularly limited, and examples thereof include dialkyl peroxides, diacyl peroxides, peroxy esters, etc. Specifically, t-butyl peroxy pivalate, dilauroyl peroxide, 1,1,3 , 3-Tetramethylbutylperoxy-2-ethylhexanate, t-butylperoxy-2-ethylhexanate, dibenzoyl peroxide, t-butylperoxy laurate, dicumyl peroxide, di-t-hexyl Organic peroxides such as peroxides can be mentioned.

Also, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis-2,4-dimethyl valeronitrile, dimethyl 2,2'-azo Azo compounds such as bis isobutyrate may be mentioned. These may be used singly or in combination of two or more.

The polymerization solvent is not particularly limited as long as it does not interfere with the polymerization, and in addition to water, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, diacetone Alcohol solvents such as alcohol, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate, n-propyl acetate and butyl acetate; ether solvents such as tetrahydrofuran and dioxane; hexane, heptane, cyclohexane, Hydrocarbon solvents such as methylcyclohexane and ethylcyclohexane; aromatic solvents such as benzene, toluene, xylene and ethylbenzene; ethylene glycol monoethyl ether, ethylene glycol mono-isopropyl ether, Chi glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, glycol ethers such as propylene glycol monoethyl ether solvent; glycol esters of propylene glycol 1-monomethyl ether 2-acetate-based solvent.
Among them, water, methanol, ethanol, n-propanol, isopropanol, acetone, methyl ethyl ketone and propylene glycol monomethyl ether are preferable. These solvents may be used alone or in combination of two or more.

The preferred weight average molecular weight of the cationic polymer is 3000 to 3,000,000. If the ratio is less than 3000, the ability to adsorb multiple points onto the cellulose surface is reduced, and the fixability may be deteriorated, and the strength of the molded article of the resin composition may be reduced. On the other hand, if it is larger than 3,000,000, agglomerates are generated due to crosslinking of the pulp fibers by the cationic polymer, and the pulp does not disperse properly at the time of mixing with the resin, thereby deteriorating the strength of the molded product of the resin composition. Sometimes.

The cellulose composition for resin reinforcement can be obtained by mixing and adsorbing at least the above-mentioned cationic polymer and cellulose fiber.

Cellulose fiber is a plant; for example, wood, bamboo, hemp, jute, kenaf, agricultural waste, cloth, pulp (softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP) ), Hardwood bleached kraft pulp (LBKP), softwood unbleached sulphite pulp (NUSP), softwood bleached sulphite pulp (NBSP), thermomechanical pulp (TMP), regenerated pulp, used paper etc), animals; eg ascidians, algae Microorganisms; for example, those originating from acetic acid bacteria (Acetobacter) and the like are known, and any of them can be used in the present invention. Preferably it is a cellulose fiber derived from a plant or a microorganism, more preferably a cellulose fiber derived from a plant. Among plant-derived cellulose fibers, pulp (in particular, softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP)) is particularly preferable. Also, these cellulose fibers may be used alone or in combination of two or more.

There is no particular limitation on the mixing method, as it is considered that if the cellulose fiber and the cationic polymer can be uniformly mixed, the cellulose fiber can be adsorbed. The cationic polymer may be added to the cellulose fiber in a solid state or in a liquid state in which the cationic polymer is dissolved or dispersed in a solvent such as water or an organic solvent, and resins, fillers, crosslinking agents, etc. are mixed in addition to cellulose fibers. It is also good.

It is preferable to mix the cellulose fiber and the cationic polymer in a solvent from the viewpoint of uniformly coating the surface of the cellulose fiber with the cationic polymer. The mixed solvent is not particularly limited, but preferred solvents include, besides water, alcohol solvents such as ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol and diacetone alcohol; Ketone solvents such as acetone and methyl ethyl ketone; amide solvents such as N-methyl-2-pyrrolidone; ether solvents such as tetrahydrofuran and dioxane; ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol mono-isopropyl ether, ethylene glycol mono Butyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, B propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. glycol ether solvents such as propylene glycol monobutyl ether. Particularly preferred are ethanol, isopropanol, n-propanol, n-butanol, acetone and N-methyl-2-pyrrolidone, which can dissolve the above-mentioned cationic polymer and soften the pulp, and these may be used alone. Two or more may be used in combination as necessary.

The resin-reinforcing cellulose fiber may be dried or may be used while containing a solvent, but is preferably dried. In the case of drying, the drying method is not particularly limited as long as the solvent can be removed at a temperature that does not cause aggregation or decomposition of the cellulose fiber or the cationic polymer. In order to suppress shrinkage of the cellulose fiber for resin reinforcement preferably at the time of drying, it is preferable to dry dynamically in a reduced pressure atmosphere while stirring the contents.

It is preferable that the ratio of the cationic polymer to the cellulose fiber in the cellulose fiber composition for resin reinforcement is cationic polymer / cellulose fiber = 9 to 50/91 to 50 in mass ratio. If the proportion of the cationic polymer is less than 9, the cellulose fibers can not be sufficiently coated, and thus the interfacial adhesion effect may not be sufficiently obtained. If the ratio of the cationic polymer is more than 50, the excess component covering the surface is liberated in the resin and dispersed unevenly, so it may be difficult to obtain the strength of the cellulose fiber composite resin molded product. is there.

The resin composition of the present invention can be obtained by mixing cellulose fiber for resin reinforcement and a resin.

The resin in the present invention is not particularly limited as long as it is usually used as a resin composition for molding materials, but thermoplastic resins and thermosetting resins are preferable. In particular, thermoplastic resins are preferred.

Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene and ethylene-propylene copolymer; polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 46 and the like; polyethylene terephthalate, polyhydroxybutyrate , Polyester resins such as polybutylene terephthalate; acrylic resins such as polymethyl methacrylate and polyethyl methacrylate; polystyrene, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-acrylic rubber-styrene copolymer, acrylonitrile-ethylene rubber-styrene copolymer Polystyrene resins such as united, (meth) acrylic acid ester-styrene copolymer, styrene-butadiene-styrene copolymer, etc .; Chlorinated resins such as polyvinyl chloride and polyvinylidene chloride; fluorocarbon resins such as polytetrafluoroethylene and polyvinylidene fluoride; silicone resins such as polydimethylsiloxane and polymethylphenylsiloxane; diene rubbers such as polybutadiene and polyisoprene; acrylic rubber, urethane rubber and the like Rubbers; polyacetal resin, polycarbonate resin, ionomer resin, polyacrylonitrile, organic acid vinyl ester resin, vinyl ether resin, ethylene-acrylic acid resin, ethylene-ethyl acrylate resin, ethylene-vinyl alcohol resin, polyphenylene ether resin, polyphenylene sulfide Resin, polylactic acid resin, polyketone resin, methyl pentene resin, cellulose resin etc. are mentioned. Among these, polyolefin resins and polyacetal resins are preferable.

The thermosetting resin may, for example, be an epoxy resin, a urethane resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, a vinyl ester resin or an alkyd resin.

The resin composition in the present invention may contain a resin and cellulose fiber for resin reinforcement, and the ratio thereof is preferably a resin / cellulose fiber for resin reinforcement = 2 to 95/98 to 5 in mass ratio. If the resin reinforcing cellulose fiber ratio is less than 2, the reinforcing effect of the resin composition may not be sufficiently obtained. When the resin reinforcing cellulose fiber ratio is more than 95, the viscosity of the resin composition may be too high, which may cause inconvenience in moldability.

The mixing method for obtaining the resin composition of the present invention is not particularly limited, but a method of adding a cellulose fiber composition for resin reinforcement to a molten resin, and an unmodified cellulose fiber in the molten resin and The method of adding a cationic polymer one by one is mentioned. At this time, when the concentration of the resin-reinforcing cellulose fiber in the resin is high, a strong shearing force is easily applied to the resin-reinforcing cellulose, so the cellulose fiber is easily dispersed in the resin. Most preferably, it is a method of adding a cellulose fiber composition for resin reinforcement to a molten resin.

In the resin composition of the present invention, talc, clay, elastomer, crystallization nucleating agent, crosslinking agent, hydrolysis inhibitor, antioxidant, lubricant, wax, colorant, to the extent that the effects of the present invention are not impaired. Stabilizers may be blended.
The mixing method can be carried out by a conventionally known method, and for example, a twin-screw kneader, a single-screw kneader, a kneader, a Banbury mixer, a pressure type kneader, a roll kneader, etc. can be used. Preferably, they are a kneader and a twin-screw kneader.

  A general molding method can be used to make the resin composition obtained as described above into a molded body. For example, injection molding, extrusion molding, blow molding, compression molding, foam molding and the like can be mentioned.

Hereinafter, examples of the present invention will be described. The present invention is not limited to these examples. Moreover,% is mass%, unless there is particular notice.

Synthesis Example 1 Synthesis Method of Cationic Polymer (A-1) Dispersion Solution 50 ml of methyl ethyl ketone as a solvent in a 500 ml round bottom flask, 4.5 g of a benzyl chloride aqueous solution of dimethylaminoethyl methacrylate as a monomer (solid content 76%), benzyl 92.4 g of methacrylate, 8.4 g of acrylamide (solid content: 50%), and 2 g of 2,2'-azobis-2-methylbutyronitrile as a polymerization initiator were charged and the temperature was raised to 80 ° C while stirring. Then, it reacted under reflux for 8 hours, and obtained a cationic polymer (A-1) dispersion solution. The solid content was 48.1%, and the weight average molecular weight was 107,000.

Synthesis Example 2 Synthesis Method of Cationic Polymer (A-2) Dispersion Solution 50 ml of methyl ethyl ketone as a solvent, 0.9 g of N-vinylformamide as a monomer, 94.8 g of benzyl methacrylate as a monomer, and acrylamide (50% of solid content) as a solvent in a 500 ml round bottom flask 4.2 g and 2 g of 2.2′-azobis-2-methylbutyronitrile as a polymerization initiator were charged and the temperature was raised to 80 ° C. while stirring. Then, it reacted for 8 hours under reflux. Thereafter, 10 g of a 5% aqueous solution of sodium hydroxide was added, and after maintaining at 80 ° C. for 2 hours, 3 g of 36% hydrochloric acid was added for neutralization to obtain a cationic polymer (A-2) dispersion solution. The solid content was 36.4%, and the weight average molecular weight was 2,750,000.

Synthesis Example 3 to 20 Synthesis Method of Cationic Polymer (A-3 to A-20) Dispersion Solution A cation polymer dispersion solution was synthesized according to the method described in Synthesis Example 1 except that the monomer species were changed as shown in Table 1. (A-3 to A-20).

Comparative Synthesis Examples 1 to 3 Synthesis Method of Cationic Polymer (AH-1 to AH-3) Dispersion Solution A polymer dispersion solution was synthesized according to the method described in Synthesis Example 1 except that the monomer species were changed as shown in Table 2. (AH-1 to AH-3).

The abbreviations in Tables 1 and 2 are as follows.
Structural unit (a): monomer structural unit (b) constituting structural unit (a) of the present invention: monomer structural unit (c) constituting structural unit (b) of the present invention: structural unit (c) of the present invention Monomer molecular weight constituting: weight average molecular weight. However, "-" shows that molecular weight measurement is not carried out.
DMBz: benzyl chloride quaternary compound of dimethylaminoethyl methacrylate VAm: vinylamine (Note 1)
DAA: diallylamine DADMAC: diallyldimethylammonium chloride DM: dimethylaminoethyl methacrylate,
BZMA: benzyl methacrylate PE200: Nippon Oil and Fats Co., Ltd. polyethylene oxide (ethylene oxide unit number = 4.5) monomethacrylate EMA: ethyl methacrylate HEMA: 2-hydroxyethyl methacrylate AAm: acrylamide DMAAm: dimethyl acrylamide ACMO: acryloyl morpholine

In the table, (Note 1) After polymerization using N-vinylformamide as the structural unit (a), a vinylamine was obtained by hydrolysis in the presence of a basic compound.

Molecular weight of cationic polymer
The molecular weight of the cationic polymer in Table 1 and Table 2 was measured using gel permeation chromatography (SHIMADZU Prominence series developing solvent, DMF detector, MALS), and the weight average molecular weight (Mw) was taken as the molecular weight.

<Cation equivalent of cationic polymer>
The cationic equivalent is the equivalent of the cationic group contained per gram of cationic polymer solids,
Cation equivalent (meq / g) = [weight fraction of cation monomer (%)] / [molecular weight of cation monomer] × [number of cationic groups contained in cation monomer] / 100 × 1000
Is represented by

Example 1 Method for Producing Cellulose Fiber for Resin Reinforcement (B-1) 1000 g (200 g of solid conversion) of water-containing softwood bleached pulp (hereinafter sometimes abbreviated as NBKP) is charged in a 5-liter flask and 3000 g of isopropanol The slurry obtained by charging, mixing and stirring was separated by pressing. Thereafter, the same operation was repeated five times on the pressed wet pulp to obtain an isopropanol wet pulp (hereinafter sometimes abbreviated as IPAWP). The solid content of the obtained IPAWP was 30.0%, and the water content was 0.5%.
Next, in a 2-liter flask, 233 g of the above IPAWP and 43.4 g of the polymer dispersion solution (A-1) synthesized in Synthesis Example 1 were mixed such that the solid content mass ratio of the cationic polymer and the cellulose fiber was 23/77. The solution was heated under reduced pressure to remove the solvent, to obtain 92 g (solid content: 98%) of a cellulose fiber (B-1) for resin reinforcement.

Examples 2 to 20 Cellulose fibers for resin reinforcement (B-) according to the method described in Example 1 except that the kind of cationic polymer and the solid content mass ratio of cationic polymer / cellulose fiber are changed as shown in Table 1. 2 to B- 20 ) were obtained.

Example 21 Method of producing cellulose fiber for resin reinforcement (B- 21 ) modified with hexadecenyl succinic anhydride modified / cationic polymer N-methyl pyrrolidone (hereinafter referred to as NMP) was added to 250 g (solid content 50 g) of water-containing NBKP. After stirring well with a stirrer, suction filtration was performed with a Buchner funnel. This operation was repeated three times to obtain 500 g of NBKP (hereinafter sometimes abbreviated as NMPSP) swollen with NMP. The obtained NMPSP 500 g was placed in a separable flask equipped with a stirrer, a thermometer and a reflux condenser, 500 g of NMP was added, and the temperature was raised to 70 ° C. while stirring. Next, 99.4 g of hexadecenylsuccinic anhydride (molecular weight 322) and 21.3 g of potassium carbonate were added and reacted at 70 ° C. for 1 hour. After the reaction, the reaction product was sequentially washed with ethanol, acetic acid water and water, and solvent substitution was carried out with ethanol to obtain 364 g (solid content: 22%) of a modified cellulose fiber (MCF1) having a hydrophobic group and a carboxyl group swollen in ethanol. . The degree of substitution (DS) of the polybasic acid anhydride of the obtained modified cellulose fiber (MCF1) was 0.35. Into this modified cellulose fiber (MCF1), 49.4 g of the cationic polymer (A-1) dispersion solution obtained in Synthesis Example 1 and 160 g of methyl ethyl ketone (hereinafter sometimes abbreviated as MEK) are mixed and heated under reduced pressure To obtain 93 g (solid content 97%) of cellulose fiber for resin reinforcement (B- 21 ).

Example 22 Preparation of Acetic Acid Modified (Acetylated) / Cationic Polymer Modified Cellulose Fiber for Resin Reinforcement (B- 22 ) 2800 g of NMP was added to 350 g (solid content: 70 g) of water-containing NBKP and stirred well with a stirrer After that, suction filtration was performed with a Buchner funnel. This operation was repeated three times to obtain 275 g of NMPSP. The obtained NMPSP (275 g) was placed in a separable flask equipped with a stirrer, a thermometer and a reflux condenser, and the temperature was raised to 70 ° C. while stirring. Then, 22.1 g of acetic anhydride (molecular weight 102) and 14.9 g of potassium carbonate were added and reacted at 70 ° C. for 3 hours. After the reaction, the reaction product was washed successively with ethanol, acetic acid water and water, and solvent substitution was carried out with ethanol to obtain 450 g (solid content: 17.8%) of acetylated modified cellulose fiber (MCF2) swollen in ethanol. The degree of substitution (DS) of the obtained modified cellulose fiber (MCF2) was 0.49. The modified cellulose fiber (MCF2) was mixed with 49.9 g of the cationic polymer (A-1) dispersion solution obtained in Synthesis Example 1 and 160 g of MEK, and the solvent was heated under reduced pressure to remove cellulose fiber for resin reinforcement (B- 22 100 g (97% solids) were obtained.

In addition, as a supporting experiment that the cationic polymer is adsorbed to the cellulose fiber, it is mixed with the cellulose in which each cationic polymer is dispersed in the solvent separately from the above each example and then filtered, and the cationic polymer hardly exists in the filtrate. confirmed.

Comparative Example 1 Production Method of Unmodified Cellulose Fiber (BH-1) The isopropanol wet pulp obtained by the method according to Example 1 was subjected to heating and vacuum desolvation in a 2 liter flask to obtain an unmodified cellulose fiber ( BH-1) 75 g (solid content 98%) were obtained.

Comparative Examples 2 to 3 and Reference Example 1 Method of Manufacturing Cellulose Fibers for Resin Reinforcement for Comparison (BH-2 to 4) According to the method described in Example 1 except that the polymer dispersion was changed as shown in Table 4. Comparative resin reinforcing cellulose fibers (BH-2 to 4) were obtained.

Comparative Example 4 Production Method of Cellulose Fiber for Comparison for Resin Reinforcement (BH-5) Modified with Aspartic Acid An ethanol was added to 71 g (solid content: 98%) of the unmodified cellulose fiber (BH-1) obtained in Comparative Example 1 162 g was mixed, 21 g of aspartic acid was mixed, and the solvent was removed under heating under reduced pressure to obtain 94 g (solid content 96%) of a cellulose fiber for resin reinforcement (BH-5) for comparison.

Comparative Example 5 Production Method of Cellulose Fiber for Comparison for Resin Reinforcement (BH-6) Modified with a Surfactant To 71 g (solid content: 98%) of the unmodified cellulose fiber (BH-1) obtained in Comparative Example 1 162 g of ethanol is mixed, 21 g of lauryl trimethyl ammonium chloride (Kao Co., Ltd. product name Cortamine 24P) is mixed, heat removal under reduced pressure is carried out, and cellulose for reinforcement for comparison (BH-6) 94 g (solid content 96%) I got

The abbreviations in Tables 3 and 4 are as follows.
IPAWP: Isopropanol wet pulp MCF1: Modified cellulose fiber MCF2 having hydrophobic group and carboxyl group swollen in ethanol: Acetylated cellulose fiber swollen in ethanol BH-1E: unmodified cellulose fiber swollen in ethanol (BH-1)
ASP: aspartic acid SF: cortamine 24P (Kao Co., Ltd. lauryltrimethyl ammonium chloride)

<Polypropylene Composite Resin Composition>

The resin melt mass flow rate values described in the following examples are resin manufacturer nominal values according to JIS standard K7210.

Example 23 Method for Producing Resin Composition (C-1) A commercially available block polypropylene (melt mass flow rate 30) and cellulose fiber for resin reinforcement (B-1) were prepared so that the content of cellulose fibers in the resin composition was 10%. A compound obtained by dry blending the above was melt-kneaded with a twin-screw kneader (manufactured by Technobel Co., Ltd .: “KZW”, screw diameter: 15 mm, L / D: 45) to obtain a composite resin (C-1).

Example 24-44 Resin compositions (C-2~ 22) of other than the manufacturing method resin reinforcing cellulose fibers was changed to Table 5, according to Example 23 resin composition (C-2~C- 22 Got)

Example 45 Production method of resin composition (C- 23 ) 200 ml of xylene was added to the cationic polymer (A-1) dispersion solution obtained in the synthesis example, distilled under reduced pressure at an external temperature of 200 ° C., and pulverized. I got a thing. Thereafter, in addition to the commercially available block polypropylene (melt mass flow rate 30), the unmodified polymer (BH-1) obtained in Comparative Example 1 and the cationic polymer solid of A-1 have a cellulose fiber content of 10%, and the cationic polymer A resin composition (C- 23 ) was obtained in the same manner as in Example 24 after dry blending so that the content was 3%.

Comparative Examples 6 to 10, Method for Producing Comparative Resin Composition (CH-1 to 6) A resin composition (CH) was prepared according to Example 23, except that the cellulose fiber for resin reinforcement was changed to Table 6. -1 to 6).

The obtained resin composition is molded into a bar-shaped test piece according to JIS Standard K7171 using an injection molding machine, and a universal testing machine "Tensilon RTM-50" manufactured by Orientec Co., Ltd. in accordance with JIS K7171. The flexural strength and flexural modulus were measured, and the rate of improvement in strength relative to commercially available block polypropylene was compared as an index.
Elastic modulus [index] = (elastic modulus of Example and Comparative Example) / (elastic modulus of commercially available block polypropylene) × 100
Strength [Index] = (Strength of Example and Comparative Example) / (Strength of Commercially Available Block Polypropylene) × 100

In the table, Note 2 indicates that the unmodified cellulose (BH-1) and the cationic polymer (A-1) solid are dry-blended with commercially available block polypropylene.

From the results of Examples 23 to 45 , it is understood that use of the cellulose fiber for resin reinforcement of the present invention has excellent mechanical strength.

From the results of Comparative Example 6 , it is found that the mechanical strength of the resin composition is insufficient when the cationic polymer specified in the present invention is not contained.

From the results of Examples 23 , 28, and 29 and Comparative Examples 7 to 8 , it is understood that sufficient mechanical strength can not be obtained when the cation equivalent of the cationic polymer does not satisfy the range defined in the present invention.

The results of Comparative Example 9 indicate that sufficient mechanical strength can not be obtained when aspartic acid is used instead of the cationic polymer defined in the present invention.

From the results of Comparative Example 10 , it can be seen that when a low molecular weight surfactant is used instead of the cationic polymer defined in the present invention, sufficient mechanical strength can not be obtained even if it exhibits cationic properties.

From the comparison of Examples 23 to 27 , excellent mechanical strength can be obtained by employing a cationic polymer synthesized using benzyl chloride quaternized of dimethylaminoethyl methacrylate and particularly diallylamine as a cationic monomer.

From the comparison of Examples 24, 32, 33 and 38 with Examples 31 and 33, it is possible to obtain further excellent mechanical strength by the cationic polymer having the structure of the structural unit (c).

From the results of Examples 23 , 43 and 44 , the machine further excellent by using a cellulose fiber for resin reinforcement using a cationic polymer for hexadecenylsuccinic anhydride modified cellulose fiber and acetic anhydride modified cellulose fiber Strength can be obtained.

From the comparison of Example 23 and Example 45, a method in which the resin is compounded as a cellulose fiber for resin reinforcement, which is previously modified with a cationic polymer, rather than separately adding a cationic polymer and unmodified cellulose to complex the resin However, the mechanical strength can be further improved.

<Polyacetal composite resin composition>

Examples 46 to 48 Manufacturing method of cellulose fiber for resin reinforcement (B- 23 to B- 25 ) Cellulose fiber for resin reinforcement according to the method described in Example 1 except that the cationic polymer is changed as shown in Table 7. (B- 23 to B- 25 ) were obtained.

Example 49 Method for Producing Resin Composition (C- 24 ) A commercially available polyacetal (melt mass flow rate 30) and cellulose fiber for resin reinforcement (B- 23 ) were dried so that the cellulose fiber fraction in the composite resin was 10%. The blended product was melt-kneaded with a twin-screw kneader (manufactured by Technobel Co., Ltd .: “KZW”, screw diameter: 15 mm, L / D: 45) to obtain a resin composition (C- 24 ).

The addition to changing the as in Examples 50-52 Resin compositions (C- 25 ~ 27) of the manufacturing method the resin reinforcing cellulose fibers in Table 8, the resin composition according to Example 49 (C-25 -C -27 ) were obtained.

Comparative Example 11 Production Method of Comparative Resin Composition (CH-7) As shown in Table 9, the cellulose fiber for resin reinforcement is a cellulose fiber for resin reinforcement for comparison, BH-2
A composite resin (CH-7) was obtained according to Example 49 except that

The obtained resin composition is molded into a bar-shaped test piece according to JIS Standard K7171 using an injection molding machine, and a universal testing machine "Tensilon RTM-50" manufactured by Orientec Co., Ltd. in accordance with JIS K7171. The flexural strength and flexural modulus were measured, and the improvement rate of strength with respect to commercially available polyacetal as in the case of the polypropylene composite resin composition was compared as an index.

<High-density polyethylene composite resin composition>

Example 53 Method of Producing Resin Composition (C- 28 ) Commercially available high-density polyethylene (melt mass flow rate 12) and cellulose fiber for resin reinforcement (B-12) in such a way that the cellulose content in the composite resin is 15%. The dry-blended product was melt-kneaded with a twin-screw kneader (manufactured by Technobel Co., Ltd .: “KZW”, screw diameter: 15 mm, L / D: 45) to obtain a resin composition (C- 28 ).

Comparative Example 12 Method of Producing Comparative Resin Composition (CH-8) As shown in Table 11, the cellulose fiber for resin reinforcement is a cellulose fiber for resin reinforcement for comparison, BH-
A resin composition for comparison (CH-8) was obtained according to Example 53 , except that it was changed to 1.

The obtained resin composition is molded into a dumbbell-shaped test piece 1BA described in JIS Standard K7162 using an injection molding machine, and according to JIS K7161, ORIENTEC Co., Ltd. manufactured universal testing machine "Tensilon RTM-50" The tensile strength and the tensile modulus of elasticity were measured, and the improvement rate of strength with respect to commercially available high density polyethylene was compared as an index in the same manner as the polypropylene composite resin composition.

  From the results of Tables 7 to 11, it can be seen that the cellulose fiber for resin reinforcement can be suitably used also for compounding other various resins such as polyacetal and high density polyethylene.

Claims (7)

Manufactured by mixing cellulose fiber with the following cationic polymer,
The cationic polymer is
Structural units (a) formed by polymerization of at least one selected from cationic vinyl monomers, and
Structural unit (b) formed by polymerization of at least one selected from nonionic (meth) acrylic esters
Have the structure of
Cation Ri equivalent of 0.05~1meq / g Der,
A method for producing a cellulose fiber for resin reinforcement, wherein the weight ratio is cationic polymer / cellulose fiber = 9 to 50/91 to 50 . The production of a cellulose fiber for resin reinforcement according to claim 1, wherein the cationic polymer further has a structure of a structural unit (c) formed by polymerization of at least one selected from (meth) acrylamides. Method. The cellulose fiber for resin reinforcement according to claim 2, wherein the (meth) acrylamide is at least one selected from (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide and acryloyl morpholine. Production method. The cellulose fiber according to any one of claims 1 to 3, wherein the cellulose fiber is modified by at least one of etherification, esterification and silylation of the hydroxyl group of cellulose. Production method. The method for producing a cellulose fiber for resin reinforcement according to claim 4, which is a cellulose fiber for thermoplastic resin reinforcement. Method for producing a resin composition containing a thermoplastic resin and resin reinforcing cellulose fibers obtained by the method for producing a resin reinforcing cellulose fibers of claim 5. Method for producing a resin molded article obtained by molding the resin composition obtained from the method for producing a resin composition according to claim 6.