JP2021169623A - Fine cellulose-containing resin composition - Google Patents

Abstract

To provide a resin composition which has good boundary adhesion to a resin, uses a CNF filler that is reduced in problems in reduction in environmental load and physical properties by a chemical modification process, and can impart a resin composite excellent in abrasion resistance and durability, and a resin composite that is a molded body of the same.SOLUTION: A resin composition contains partially hydrolyzed fine cellulose (A) and a thermoplastic resin (B). A resin composition contains partially hydrolyzed fine cellulose (A), a thermoplastic resin (B) and hemicellulose (C). In a preferred embodiment, the partially hydrolyzed fine cellulose (A) is a fine cellulose fiber having a fiber length/fiber diameter aspect ratio of 30 or more.SELECTED DRAWING: None

Description

The present invention relates to a resin composition containing fine cellulose having a partially hydrolyzed structure, and more particularly to a resin composition capable of giving a molded product having good sliding characteristics.

Thermoplastic resins are light and have excellent processing characteristics, and are therefore widely used in various fields such as automobile parts, electrical / electronic parts, office equipment housings, and precision parts. However, the resin alone often has insufficient mechanical properties, slidability, thermal stability, dimensional stability, and the like, and a composite of the resin and various inorganic materials is generally used.

A resin composition in which a thermoplastic resin is reinforced with a reinforcing material such as glass fiber, carbon fiber, talc, or clay, which is an inorganic filler, has a high specific gravity, so that there is a problem that the weight of the obtained resin molded body becomes large.

Therefore, in recent years, cellulose, which has a low environmental load, has come to be used as a new reinforcing material for resins.

Cellulose is known to have a high elastic modulus comparable to that of aramid fiber and a coefficient of linear expansion lower than that of glass fiber as its elemental properties. In addition, the true density is as ^{low as 1.56 g / cm 3, and glass (density 2.4 to 2.6 g / cm 3} ) and talc (density 2.7 g / cm) used as reinforcing materials for general thermoplastic resins are used. It is an overwhelmingly lighter material than ^3).

In addition to those made from trees, cellulose is also made from hemp, cotton, kenaf, cassava, etc. Furthermore, bacterial cellulose such as nata de coco is also known. There are a large amount of natural resources as raw materials on the earth, and in order to make effective use of them, the technology of utilizing cellulose as a filler in the resin is drawing attention.

In order to fully exert the characteristics of cellulose, it is necessary to create a fine and uniform dispersed state in the thermoplastic resin. Cellulose obtained from natural resources physically and / or chemically binds to hemicellulose and lignin to form a strong cell wall. Therefore, in order to use it as a fine filler, the cellulose fibers are broken into fine particles. A step of taking out the cellulose fibers is performed. Cellulose fibers defibrated to the nanometer order of less than 1 micron are called CNF (cellulose nanofibers), and pulp obtained by pretreating plant-derived natural resources such as cooking, selection, and bleaching. By mechanical defibration methods such as high-pressure homogenizer treatment, microfluidizer treatment, underwater facing collision, ball mill and disc mill treatment, and low energy defibration by chemical treatment such as TEMPO oxidation and cellulose esterification. It is obtained and is known to form a highly dispersed state or network at a level called fine nanodispersion in water.

Thermoplastic resins and celluloses that are generally used often have poor affinity due to differences in surface free energy, and because the interfacial adhesion between CNF and thermoplastic resin is low, their characteristics cannot be fully exhibited in many cases. On the other hand, a method using chemically modified modified cellulose nanofibers for modifying the surface state of cellulose is known (Patent Document 1).

Japanese Unexamined Patent Publication No. 2017-171698

However, in order to chemically modify the cellulose nanofibers dispersed in water, a solvent replacement treatment is required. The solvent replacement treatment not only increases the cost required for producing cellulose nanofibers, but also increases by-product waste and energy consumption, and reduces the advantage of cellulose having a low environmental load.

Further, there is also known a method of obtaining modified cellulose nanofibers by adsorbing a counterionic additive in water on the ionized-modified cellulose nanofibers, but the heat resistance of the ionized-modified cellulose is lowered. Cellulose nanofibers undergo thermal decomposition in the process of being kneaded with the resin at a high temperature and cannot exhibit the original reinforcing effect, which may cause unstable quality, equipment trouble, and the like.

The present invention uses a CNF filler that solves the above-mentioned problems of the prior art, has good interfacial adhesion with a resin, and reduces the problems of environmental load and deterioration of physical properties due to the chemical modification process, and has wear resistance and abrasion resistance. It is an object of the present invention to provide a resin composition and a resin composite which is a molded product thereof, which can give a resin composite having excellent durability.

As a result of diligent studies to solve the above-mentioned problems, the present inventor has found that a resin composition containing partially hydrolyzed cellulose and further containing a specific compound can solve the above-mentioned problems, and makes the present invention. It came to.
That is, the present invention includes the following aspects.

[1] A resin composition containing partially hydrolyzed fine cellulose (A) and a thermoplastic resin (B).
[2] The resin composition according to the above aspect 1, further comprising hemicellulose (C).
[3] The resin composition according to the above aspect 1 or 2, wherein the partially hydrolyzed fine cellulose (A) is a fine cellulose fiber having a fiber length / fiber diameter aspect ratio of 30 or more.
[4] The partially hydrolyzed fine cellulose (A) has a peak top molecular weight corresponding to a degree of polymerization of 450 or more.
In the partially hydrolyzed fine cellulose (A), when the amount of the low molecular weight component having a molecular weight equal to or lower than the peak top molecular weight is S1 and the amount of the high molecular weight component having a molecular weight exceeding the peak top molecular weight is S2, S1 The resin composition according to any one of the above aspects 1 to 3, wherein / S2 is larger than 1.00.
[5] The resin composition according to the fourth aspect, wherein S1 / S2 is greater than 1.00 and less than or equal to 3.00.
[6] The resin composition according to any one of the above aspects 1 to 5, wherein the partially hydrolyzed fine cellulose (A) has an average fiber diameter of 4 to 3000 nm.
[7] The method according to any one of the above aspects 1 to 6, wherein the mass ratio (A) / (B) of the partially hydrolyzed fine cellulose (A) / thermoplastic resin (B) is 0.01 to 1. Resin composition.
[8] The resin composition contains hemicellulose (C), and the mass ratio (C) / (A) of hemicellulose (C) / partially hydrolyzed fine cellulose (A) is 0.001 to 0.2. , The resin composition according to any one of the above aspects 1 to 7.
[9] The above embodiment, wherein the resin composition contains hemicellulose (C) and lignin (D), and the mass ratio (D) / (C) of lignin (D) / hemicellulose (C) is 0.001 to 10. The resin composition according to any one of 1 to 8.
[10] The resin composition according to any one of the above aspects 1 to 9, wherein the thermoplastic resin (B) is a polyamide resin.
[11] The method for producing a resin composition according to any one of the above aspects 1 to 10.
By heating the fine cellulose and / or the plant fiber in an atmosphere containing water and having an oxygen concentration of 18% by volume or less, a compounding component containing the partially hydrolyzed fine cellulose (A) can be obtained, and the above-mentioned compounding. Combining the components with the thermoplastic resin (B),
Including methods.
[12] A slidable member which is a molded product of the resin composition according to any one of the above aspects 1 to 10.

According to the present invention, a CNF filler having good interfacial adhesion with a resin and having reduced problems of environmental load and deterioration of physical properties due to a chemical modification process is used to provide a resin composite having excellent wear resistance and durability. A resin composition which can be provided, and a resin composite which is a molded product thereof can be provided.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

<Resin composition>
In one aspect, the resin composition comprises partially hydrolyzed fine cellulose (A) and a thermoplastic resin (B). In one aspect, the resin composition comprises partially hydrolyzed fine cellulose (A), thermoplastic resin (B), and hemicellulose (C).

[(A) Partially hydrolyzed fine cellulose]
The partially hydrolyzed fine cellulose (A) may be derived from various raw materials. Examples of cellulose as a raw material include natural cellulose and regenerated cellulose.

Natural cellulose includes wood pulp obtained from wood species (bamboo or softwood), non-wood pulp obtained from non-wood species (bamboo, hemp fiber, bagasse, kenaf, linter, etc.), and refined pulp (refined linter) thereof. ) Etc. can be used. As the non-wood pulp, cotton-derived pulp containing cotton linter pulp, hemp-derived pulp, bagasse-derived pulp, Kenaf-derived pulp, bamboo-derived pulp, straw-derived pulp, banana-derived pulp and the like can be used. Cotton-derived pulp, hemp-derived pulp, bagasse-derived pulp, Kenaf-derived pulp, bamboo-derived pulp, straw-derived pulp, and banana-derived pulp are cotton lint, cotton linter, and hemp-based abaca (eg, from Ecuador or the Philippines, respectively). It is preferable that the pulp is obtained from raw materials such as sisal, bagasse, kenaf, bamboo, straw, banana stalk, etc. through a purification step such as delignin by cooking treatment, a bleaching step, and the like. In addition, cellulose derived from seaweed can also be used.

Regenerated cellulose is a substance obtained by dissolving or crystallizing (mercerizing) natural cellulose and regenerating it, and the number of times corresponding to the lattice spacing of 0.73 nm, 0.44 nm and 0.40 nm by particle beam diffraction. It refers to a β-1,4-linked glucan (glucose polymer) having a molecular arrangement that gives a crystal diffraction pattern (cellulose type II crystal) with a folding angle at the apex. In the regenerated cellulose, in the X-ray diffraction pattern, the X-ray diffraction pattern in which the range of 2θ is 0 ° to 30 ° has one peak at 10 ° ≤ 2θ <19 ° and two at 19 ° ≤ 2θ ≤ 30 °. Has a peak. Examples of the regenerated cellulose include rayon, cupra, tencel and the like. Since it is easy to produce fibers having a fiber diameter of more than 100 nm from regenerated cellulose, regenerated cellulose may be preferable from the viewpoint of dispersibility in the resin. As raw materials for fine cellulose, cupra and tencel having high molecular orientation in the fiber axis direction are particularly preferable from the viewpoint of ease of miniaturization. Further, cut yarns of regenerated cellulose fibers, cut yarns of cellulose derivative fibers and the like can also be used as raw materials. Further, natural cellulose and regenerated cellulose may be mixed and used as raw materials.

It is generally known that cellulose fibers contain regularly arranged crystal structure portions and irregular amorphous structure portions. Normally, about 40 cellulose molecules form microfibrils having a width of about 4 to 5 nm by intermolecular hydrogen bonds, and a plurality of microfibrils gather to form a bundle having a width of about 15 nm or more. Cellulose nanofibers are those in which these bundles are further gathered and defibrated to a state having a fiber diameter of several tens to several hundreds of nm to the equivalent of microfibrils. The surface area of the cellulose fiber is increased by being defibrated, and the interface when composited with the resin is increased, so that the effect of improving the mechanical properties (reinforcing effect) is increased. However, in the case of fine cellulose fibers close to microfibrils, which have been further defibrated, decomposition from the surface is likely to occur due to heating in the compositing step with the resin. The average fiber diameter of the partially hydrolyzed fine cellulose (A) is preferably 4 nm or more, more preferably 15 nm or more, further preferably 30 nm or more, and particularly preferably 50 nm or more. On the other hand, if the average fiber diameter of the partially hydrolyzed fine cellulose (A) is too large, the reinforcing effect is lowered and the surface roughness of the resin composite may be increased to deteriorate the design. Therefore, the average fiber diameter may be deteriorated. It is preferably 3000 nm or less, more preferably 2000 nm or less, further preferably 1500 nm or less, and particularly preferably 1000 nm or less. The average fiber diameter is a value measured by the method described in the [Example] section of the present disclosure.

Properties such as high elastic modulus and low coefficient of linear expansion of cellulose are mainly due to the crystal structure. Since the cellulose molecules in the crystal structure portion are strongly hydrogen-bonded to each other, they are difficult to be hydrolyzed, but the amorphous portion is easily hydrolyzed. In crystalline cellulose in which cellulose molecules in the amorphous portion are cleaved by acid hydrolysis and the degree of polymerization is refined to about 200 to 300, the aspect ratio of length / thickness is about several tens at the maximum, and cellulose nanowhisker and cellulose are used. It is called nanocrystal. When miniaturized to this size, it is difficult to form a network due to the interaction between cellulose nanocrystals in the resin when composited with the resin, so that the reinforcing effect is also difficult to be exhibited. Further, such cellulose nanocrystals tend to have lower heat resistance than cellulose nanofibers having a large aspect ratio. It is considered that the starting point of thermal decomposition is increased by increasing the fiber surface area and / or the number of cellulose molecule terminals.

The partially hydrolyzed fine cellulose (A) is such that at least a part of the amorphous portion is hydrolyzed, and cellulose nanocrystals having a low aspect ratio are not decomposed. The aspect ratio of the length / thickness (fiber length / fiber diameter) of the partially hydrolyzed fine cellulose (A) is preferably 30 or more, more preferably 50 or more, and further preferably 100 or more. By observing the fine cellulose used as a raw material or the fine cellulose recovered by dissolving and removing the resin from the resin composition with a scanning electron microscope (SEM), the content of the fine cellulose having a lower aspect ratio than the above preferable range can be found. You can check it. It is preferable that the amount of fine cellulose cut to such a low aspect ratio is small in the resin composition, but it may be present within a range in which the desired reinforcing effect of the resin composition of the present invention can be exhibited. The aspect ratio is a value measured by the method described in the [Example] section of the present disclosure.

Although it is difficult to directly observe the local molecular structure of the fine cellulose, the structure of the partially hydrolyzed fine cellulose of the present invention can be considered as follows from the results of macro-scale analysis. When cellulose is hydrolyzed, for example, by heating in the presence of water under neutral to weakly acidic conditions, at least a portion of the amorphous moiety is hydrolyzed while the crystal structure is substantially maintained. Hydrolyzed cellulose can be obtained. Such partially hydrolyzed cellulose contains a large amount of cellulose having a low degree of polymerization when the molecular weight distribution is measured, but hardly contains fine cellulose having a low aspect ratio in morphological observation. That is, in the partially hydrolyzed cellulose, in the microfibrils or the microfibril bundle, the hydrolysis does not substantially occur in the inner layer, and the hydrolysis of the surface layer is limited to a part, so that the cellulose has a high aspect ratio. Can exist as fine cellulose of.

The partially hydrolyzed fine cellulose (A) can be analyzed by various methods generally used for the analysis of cellulose. The measurement of the molecular weight distribution is preferably performed by gel permeation chromatography (GPC). The molecular weight distribution is monomodal with one peak, bimodal with two peaks, and in rare cases it may have three or more peaks, but the peak top molecular weight (ie, the apex of the maximum peak). It is divided into a low molecular weight side and a high molecular weight side based on the molecular weight). The peak top molecular weight can be converted into a degree of polymerization by dividing by the molecular weight 162 of the anhydrous glucose unit, which is a monomer structure of cellulose. At this time, the degree of polymerization corresponding to the peak top molecular weight is preferably 300 or more, more preferably 400 or more, further preferably 450 or more, and particularly preferably 500 or more. When the peak top molecular weight is at least the above degree of polymerization, the excessive progress of partial hydrolysis is suppressed, the content of fine cellulose having a low aspect ratio equivalent to that of cellulose nanocrystals is small, and the heat resistance is good. In the molecular weight measurement, S1 / S2 is defined as S1 for the amount of low molecular weight component having a molecular weight equal to or lower than the peak top molecular weight (cumulative area strength) and S2 for the amount of high molecular weight component having a molecular weight exceeding the peak top molecular weight (cumulative area strength). The lower limit of the ratio is preferably more than 1.00, more preferably 1.05 or more, further preferably 1.10 or more, further preferably 1.15 or more, and particularly preferably 1.20 or more. When S1 / S2 is equal to or greater than these ratios, the partially hydrolyzed fine cellulose (A) provides good tensile strength, coefficient of friction, and wear depth of the resin composite. The upper limit of the S1 / S2 ratio is preferably 3.00 or less, more preferably 2.50 or less, further preferably 2.00 or less, still more preferably 1.90 or less, and particularly preferably 1.80 or less. When S1 / S2 is equal to or less than these ratios, thermal decomposition and performance deterioration due to heating when kneading the resin composite are suppressed.

The reason why the partially hydrolyzed fine cellulose (A) exhibits a superior effect to the normal (that is, not partially hydrolyzed) fine cellulose is presumed as follows. When the amorphous portion of cellulose is hydrolyzed, a newly reducing end (1st position of glucose unit) and a non-reducing end (4th position of glucose unit) are generated. Of these, the reducing terminal is in an equilibrium state between the hemiacetal group and the aldehyde group, and the aldehyde group is present in the main chain and / or side chain of the thermoplastic resin and / or the terminal, and is an amino group or a carboxy group. , A covalent bond can be formed by reacting with a functional group such as a hydroxy group. As a result, the interfacial adhesion between the fine cellulose and the thermoplastic resin is strengthened.

[Hemicellulose (C) and lignin (D)]
In one aspect, the resin composition further comprises hemicellulose (C) and / or lignin (D) (more typically both hemicellulose (C) and lignin (D)). Usually, in plant-derived fine cellulose, polysaccharides collectively called hemicellulose and aromatic compounds collectively called lignin remain between microfibrils and between microfibril bundles. In the present invention, it is preferable that these components are not completely removed in the process of producing fine cellulose, but are left in a content within a suitable range. Hemicellulose is a polysaccharide composed of sugars such as mannan and xylan, and plays a role of hydrogen bonding with cellulose to connect microfibrils. Further, since the solubility parameter (SP value) of hemicellulose is on the hydrophobic side with respect to cellulose, hemicellulose is considered to have an effect of alleviating the SP value difference between the thermoplastic resin and the fine cellulose.

The amount of hemicellulose (C) in the resin composition of the present invention is preferably 0.001 or more, preferably 0.005 or more, in terms of mass ratio (C) / (A) to partially hydrolyzed fine cellulose (A). Is more preferable, 0.01 or more is further preferable, 0.02 or more is further preferable, 0.03 or more is particularly preferable, 0.2 or less is more preferable, 0.18 or less is more preferable, and 0.15 or less is further preferable. preferable. When hemicellulose (C) is contained in the above range, the resin composite is pulled because the peeling of the cellulose molecules having a low degree of polymerization from the surface layer when the fine cellulose is partially hydrolyzed is suppressed. Good strength, coefficient of friction, and wear depth.

Lignin is a compound having an aromatic ring and is known to be covalently bound to hemicellulose in the cell wall of plants. The amount of lignin (D) in the resin composition of the present invention is preferably 0.001 or more, more preferably 0.01 or more, and 0. 1 or more is more preferable, 10 or less is preferable, 5 or less is more preferable, and 3 or less is further preferable. Lignin is a more hydrophobic compound than hemicellulose, and is considered to have an effect of further satisfactorily alleviating the SP value difference between the thermoplastic resin and fine cellulose. It is not preferable that the abundance of hemicellulose and lignin does not exceed the above range because it induces a decrease in heat resistance and accompanying discoloration in the resin composite.

The amount of hemicellulose (C) can be adjusted by reducing the amount of hemicellulose (C) to a desired amount by subjecting a natural wood raw material having a high hemicellulose content to a desired amount, or a raw material having a low hemicellulose content is used. In the case, the desired amount can be adjusted by adding hemicellulose obtained by extraction treatment from another raw material. At this time, the structure such as the end of hemicellulose may be partially different from the natural product by purification or extraction treatment.
Further, the amount of lignin (D) can be adjusted by reducing the amount of natural wood raw material having a high lignin content to a desired amount by performing a refining treatment, and a raw material having a low lignin content can be used. When used, it can be adjusted to a desired amount by adding lignin obtained by extraction treatment from another raw material. At this time, the structure such as the terminal of lignin may be partially different from the natural product by purification or extraction treatment.

[Thermoplastic resin (B)]
Examples of the thermoplastic resin (B) include a crystalline resin having a melting point in the range of 100 ° C. to 350 ° C. and an amorphous resin having a glass transition temperature in the range of 100 ° C. to 250 ° C.

The melting point of the crystalline resin referred to here is the peak top of the endothermic peak that appears when the temperature is raised from 23 ° C to 10 ° C / min using a differential scanning calorimetry device (DSC). Refers to temperature. When two or more endothermic peaks appear, it means the peak top temperature of the endothermic peak on the highest temperature side. The enthalpy of the endothermic peak at this time is preferably 10 J / g or more, and more preferably 20 J / g or more. In the measurement, it is desirable to use a sample in which the sample is once heated to a temperature condition of melting point + 20 ° C. or higher, the resin is melted, and then cooled to 23 ° C. at a temperature lowering rate of 10 ° C./min.

The glass transition temperature of the amorphous resin referred to here is when measured at an applied frequency of 10 Hz while raising the temperature from 23 ° C. to 2 ° C./min using a dynamic viscoelasticity measuring device. In addition, it refers to the peak top temperature at which the storage elastic modulus is greatly reduced and the loss elastic modulus is maximized. When two or more peaks of loss elastic modulus appear, it means the peak top temperature of the peak on the highest temperature side. The measurement frequency at this time is preferably at least once every 20 seconds in order to improve the measurement accuracy. The method for preparing the sample for measurement is not particularly limited, but from the viewpoint of eliminating the influence of molding strain, it is desirable to use a cut piece of a hot press molded product, and the size (width and thickness) of the cut piece can be as small as possible. The smaller one is preferable from the viewpoint of heat conduction.

The thermoplastic resin (B) is modified by blending or graft-polymerizing a polyamide resin, a polyester resin, a polyacetal resin, a polycarbonate resin, a polyacrylic resin, or a polyphenylene ether resin (polyphenylene ether with another resin). (Including modified polyphenylene ether), polyarylate resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, polyketone resin, polyphenylene ether ketone resin, polyimide resin, polyamideimide resin, polyetherimide Examples thereof include based resins, polyurethane resins, polyolefin resins (for example, α-olefin (co) polymers), and various ionomers.

Preferred specific examples of the thermoplastic resin (B) are high-density polyethylene, low-density polyethylene (for example, linear low-density polyethylene), polypropylene, polymethylpentene, cyclic olefin-based resin, poly1-butene, poly1-pentene, and the like. Polymethylpentene, ethylene / α-olefin copolymer, ethylene / butene copolymer, EPR (ethylene-propylene copolymer), modified ethylene / butene copolymer, EEA (ethylene-ethylacrylate copolymer), modified EEA, modified EPR, modified EPDM (ethylene-propylene-diene ternary copolymer), ionomer, α-olefin copolymer, modified IR (isoprene rubber), modified SEBS (styrene-ethylene-butylene-styrene copolymer) , Halogenized isobutylene-paramethylstyrene copolymer, ethylene-acrylic acid modified product, ethylene-vinyl acetate copolymer, and acid-modified product thereof, (ethylene and / or propylene) and (unsaturated carboxylic acid and / or non-saturated carboxylic acid). At least a part of the carboxyl groups of the copolymer with (saturated carboxylic acid ester) and the copolymer of (ethylene and / or propylene) and (unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) is metal chlorided. Obtained polyolefin, block copolymer of conjugated diene and vinyl aromatic hydrocarbon, hydride of block copolymer of conjugated diene and vinyl aromatic hydrocarbon, copolymer of other conjugated diene compound and non-conjugated olefin, Natural rubber, various butadiene rubbers, various styrene-butadiene copolymer rubbers, isoprene rubbers, butyl rubbers, bromide of copolymers of isobutylene and p-methylstyrene, butyl halide rubbers, acrylonitrillobutadiene rubbers, chloroprene rubbers, ethylene-propylene Copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, isoprene-butadiene copolymer rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin Acrylonitrile-based copolymers mainly composed of acrylics such as rubber, polysulfide rubber, silicone rubber, fluororubber, urethane rubber, polyvinyl chloride, polystyrene, polyacrylic acid ester, polymethacrylic acid ester, and acrylonitrile, acrylonitrile-butandien. Styrene (ABS) resin, acrylonitrile / styrene (AS) resin, cellulose-based resin such as cellulose acetate, chloride Examples thereof include vinyl / ethylene copolymers, vinyl chloride / vinyl acetate copolymers, ethylene / vinyl acetate copolymers, and saponified products of ethylene / vinyl acetate copolymers.

These may be used alone or in combination of two or more. When two or more kinds are used in combination, it may be used as a polymer alloy. Further, the above-mentioned thermoplastic resin modified with at least one compound selected from an unsaturated carboxylic acid, an acid anhydride thereof or a derivative thereof can also be used.

Among these, from the viewpoints of heat resistance, moldability, design and mechanical properties, polyolefin resins, polyamide resins, polyester resins, polyacetal resins, polyacrylic resins, polyphenylene ether resins, polyphenylene sulfide resins and Examples include, but are not limited to, mixtures of two or more of these. Among these, polyolefin-based resins, polyamide-based resins, polyester-based resins, polyacetal-based resins, and the like are more preferable resins from the viewpoint of handleability and cost.

The polyolefin-based resin is a polymer obtained by polymerizing a monomer unit containing olefins (for example, α-olefins). Specific examples of the polyolefin-based resin are not particularly limited, but are exemplified by low-density polyethylene (for example, linear low-density polyethylene), high-density polyethylene, ultra-low-density polyethylene, ultra-high-molecular-weight polyethylene, and the like. Polyethylene-based (co) polymers, ethylene-acrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene, which are exemplified by coalescing, polypropylene, ethylene-propylene copolymers, ethylene-propylene-diene copolymers, etc. Examples thereof include a copolymer of α-olefin represented by a glycidyl methacrylate copolymer and the like and another monomer unit.

Here, polypropylene is mentioned as the most preferable polyolefin resin. In particular, polypropylene having a melt mass flow rate (MFR) of 3 g / 10 minutes or more and 30 g / 10 minutes or less measured at 230 ° C. and a load of 21.2 N in accordance with ISO1133 is preferable. The lower limit of MFR is more preferably 5 g / 10 min, even more preferably 6 g / 10 min, and most preferably 8 g / 10 min. The upper limit is more preferably 25 g / 10 minutes, even more preferably 20 g / 10 minutes, and most preferably 18 g / 10 minutes. It is desirable that the MFR does not exceed the above upper limit value from the viewpoint of improving the toughness of the composition, and it is desirable that the MFR does not exceed the above lower limit value from the viewpoint of the fluidity of the composition.

Further, in order to enhance the affinity with cellulose, an acid-modified polyolefin resin can also be preferably used. The acid can be appropriately selected from maleic acid, fumaric acid, succinic acid, phthalic acid and anhydrides thereof, polycarboxylic acids such as citric acid and the like. Of these, maleic acid or an anhydride thereof is preferable because of the ease of increasing the denaturation rate. The modification method is not particularly limited, but a general method is to heat the resin above the melting point and melt-knead it in the presence / absence of a peroxide. As the acid-modified polyolefin resin, all of the above-mentioned polyolefin-based resins can be used, but polypropylene is particularly preferable.

The acid-modified polyolefin-based resin may be used alone, but it is more preferable to use the acid-modified polyolefin-based resin in combination with an unmodified polyolefin-based resin in order to adjust the modification rate as a composition. For example, when a mixture of unmodified polypropylene and acid-modified polypropylene is used, the ratio of acid-modified polypropylene to total propylene is preferably 0.5% by mass to 50% by mass. A more preferable lower limit is 1% by mass, still more preferably 2% by mass, even more preferably 3% by mass, particularly preferably 4% by mass, and most preferably 5% by mass. The upper limit is more preferably 45% by mass, still more preferably 40% by mass, even more preferably 35% by mass, particularly preferably 30% by mass, and most preferably 20% by mass. In order to maintain the interfacial strength with cellulose, the lower limit or more is preferable, and in order to maintain the ductility as a resin, the upper limit or less is preferable.

The melt mass flow rate (MFR) measured at 230 ° C. and a load of 21.2 N according to the preferred ISO 1133 of the acid-modified polypropylene should be 50 g / 10 min or more in order to enhance the affinity with the cellulose interface. preferable. A more preferable lower limit is 100 g / 10 minutes, even more preferably 150 g / 10 minutes, and most preferably 200 g / 10 minutes. There is no particular upper limit, but it is 500 g / 10 minutes from the maintenance of mechanical strength. By setting the MFR within this range, it is possible to enjoy the advantage that it easily exists at the interface between the cellulose and the resin.

The polyamide-based resin preferable as the thermoplastic resin is not particularly limited, but polyamide 6, polyamide 11, polyamide 12 and the like obtained by the polycondensation reaction of lactams; 1,6-hexanediamine, 2-methyl-1,5- Pentandiamine, 1,7-heptanediamine, 2-methyl-1-6-hexanediamine, 1,8-octanediamine, 2-methyl-1,7-heptanediamine, 1,9-nonanediamine, 2-methyl-1 , 8-octanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, m-xylylene diamine and other diamines, butanedioic acid, pentanedioic acid, hexanedioic acid, Heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, benzene-1,2-dicarboxylic acid, benzene-1,3-dicarboxylic acid, benzene-1,4 dicarboxylic acid, etc., cyclohexane-1,3-dicarboxylic acid Polyamides 6,6, polyamides 6,10, polyamides 6,11, polyamides 6,12, polyamides 6, T, polyamides 6, obtained as copolymers with dicarboxylic acids such as acids and cyclohexane-1,4-dicarboxylic acids. I, polyamide 9, T, polyamide 10, T, polyamide 2M5, T, polyamide MXD, 6, polyamide 6, C, polyamide 2M5, C, etc .; and a copolymer obtained by copolymerizing these (polyamide 6 as an example). , T / 6, I) and the like;

Among these polyamide-based resins, aliphatic polyamides such as polyamide 6, polyamide 11, polyamide 12, polyamide 6, 6, polyamide 6, 10, polyamide 6, 11, polyamide 6, 12 and polyamide 6, C, polyamide 2 M5, C The alicyclic polyamide such as is more preferable.

The concentration of the terminal carboxyl group of the polyamide resin is not particularly limited, but the lower limit is preferably 20 μmol / g, more preferably 30 μmol / g. The upper limit of the terminal carboxyl group concentration is preferably 150 μmol / g, more preferably 100 μmol / g, and further preferably 80 μmol / g.

In the polyamide resin, the ratio of the carboxyl terminal group to the preferable total terminal group ([COOH] / [total terminal group]) is more preferably 0.30 to 0.95. The lower limit of the carboxyl-terminal group ratio is more preferably 0.35, even more preferably 0.40, and most preferably 0.45. The upper limit of the carboxyl-terminal group ratio is more preferably 0.90, even more preferably 0.85, and most preferably 0.80. The carboxyl-terminal group ratio is preferably 0.30 or more from the viewpoint of dispersibility of the cellulose component in the composition, and is preferably 0.95 or less from the viewpoint of the color tone of the obtained composition.

As a method for adjusting the terminal group concentration of the polyamide resin, a known method can be used. For example, diamine compounds, monoamine compounds, dicarboxylic acid compounds, monocarboxylic acid compounds, acid anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols, etc. Examples thereof include a method of adding an end modifier that reacts with an end group to the polymerization solution.

Examples of the terminal modifier that reacts with the terminal amino group include acetic acid, propionic acid, butylic acid, valeric acid, caproic acid, capric acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutylic acid. And other aliphatic monocarboxylic acids; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. Carboxylic acids; and a plurality of mixtures arbitrarily selected from these. Among these, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, etc. One or more end regulators selected from the group consisting of valeric acid and valeric acid are preferable, and acetic acid is most preferable.

Examples of the terminal modifier that reacts with the terminal carboxyl group include aliphatic groups such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine and dibutylamine. Monoamines; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine and any mixtures thereof. Among these, one or more terminals selected from the group consisting of butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline from the viewpoints of reactivity, boiling point, stability of sealing terminal, price and the like. Regulators are preferred.

The concentrations of these amino-terminal groups and carboxyl-terminal groups are preferably obtained by ¹ H-NMR from the integrated value of the characteristic signal corresponding to each terminal group in terms of accuracy and simplicity. As a method for determining the concentration of these terminal groups, specifically, the method described in JP-A-7-228775 is recommended. When this method is used, ditrifluoroacetic acid is useful as the measurement solvent. In addition, the ^{number of integrations of 1 1} H-NMR requires at least 300 scans even when measured with a device having sufficient resolution. In addition, the concentration of the terminal group can also be measured by a measurement method by titration as described in JP-A-2003-055549. However, in order to reduce the influence of mixed additives, lubricants, etc. as much as possible, ¹ H-NMR quantification is more preferable.

The polyester-based resin preferable as the thermoplastic resin is not particularly limited, but is not particularly limited, but is polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene succinate (PBS), polybutylene succinate adipate ( Selected from PBSA), polybutylene adipate terephthalate (PBAT), polyallylate (PAR), polyhydroxyalkanoic acid (PHA) (polyester resin composed of 3-hydroxyalkanoic acid), polylactic acid (PLA), polycarbonate (PC), etc. One kind or two or more kinds can be used. Among these, more preferable polyester-based resins include PET, PBS, PBSA, PBT, and PEN, and more preferably, PBS, PBSA, and PBT.

Further, in the polyester resin, the terminal group can be freely changed depending on the monomer ratio at the time of polymerization and the presence / absence and amount of the terminal stabilizer added, but the ratio of the carboxyl terminal group to the total terminal group of the polyester resin. ([COOH] / [all terminal groups]) is preferably 0.30 to 0.95. The lower limit of the carboxyl-terminal group ratio is more preferably 0.35, further preferably 0.40, and most preferably 0.45. The upper limit of the carboxyl-terminal group ratio is more preferably 0.90, further preferably 0.85, and most preferably 0.80. The carboxyl-terminal group ratio is preferably 0.30 or more from the viewpoint of dispersibility of the cellulose component in the composition, and is preferably 0.95 or less from the viewpoint of the color tone of the obtained composition.

Preferable polyacetal resins as thermoplastic resins are generally homopolyacetal made from formaldehyde and copolyacetal containing trioxane as a main monomer and, for example, 1,3-dioxolan as a comonomer component, and both can be used. However, from the viewpoint of thermal stability during processing, copolyacetal can be preferably used. In particular, the amount of the comonomer component (for example, 1,3-dioxolane) is preferably in the range of 0.01 to 4 mol%. A more preferable lower limit of the amount of the comonomer component is 0.05 mol%, more preferably 0.1 mol%, and particularly preferably 0.2 mol%. The more preferable upper limit amount is 3.5 mol%, more preferably 3.0 mol%, particularly preferably 2.5 mol%, and most preferably 2.3 mol%. From the viewpoint of thermal stability during extrusion and molding, it is desirable that the lower limit is within the above range, and from the viewpoint of mechanical strength, the upper limit is preferably within the above range.

The thermoplastic resin (B) is preferably a polyamide-based resin in that it has an amino group at the end that easily reacts with the newly generated reduced terminal aldehyde in the partially hydrolyzed fine cellulose (A).

The number average molecular weight Mn of the thermoplastic resin (B) is not particularly limited, and it may be processed by a molding method such as injection molding, extrusion molding, or blow molding that is generally used when molding the resin composition. It is known that when the number average molecular weight Mn of the thermoplastic resin (B) is low, the mechanical properties and impact resistance of the resin composition are lowered, but the resin composition of the present invention is partially hydrolyzed and fine. Since it has good adhesion to cellulose (A), it can be applied to a thermoplastic resin having a low number average molecular weight Mn. For example, even if the number average molecular weight Mn of the thermoplastic resin (B) is less than 14,000, less than 13,000, less than 12,000, less than 11,000, and less than 10,000, good mechanical strength can be obtained. The number average molecular weight is a value obtained in terms of polymethyl methacrylate using gel permeation chromatography (GPC).

The mass ratio (A) / (B) of the amount of the partially hydrolyzed fine cellulose (A) to the amount of the thermoplastic resin (B) in the resin composition depends on the partially hydrolyzed fine cellulose (A). From the viewpoint of obtaining a good reinforcing effect, it is preferably 0.01 or more, more preferably 0.02 or more, further preferably 0.03 or more, and from the viewpoint of satisfactorily forming a molded body, preferably 1 or less, more preferably It is 0.70 or less, more preferably 0.45 or less, and particularly preferably 0.25 or less.

[Other ingredients]
Other components of the resin composition of the present invention include, for example, antioxidants; crystal nucleating agents; compatibilizers; plasticizers; colorants; fragrances; pigments; flow modifiers; leveling agents; conductive agents; antistatic agents. Agents; UV absorbers; UV dispersants; Deodorants; Bactericides; Flame retardants and other additives may be blended. The content ratio of any additive may be appropriately set as long as the desired effect of the present invention is not impaired.

<Manufacturing method of resin composition>
The resin composition of the present invention can be produced by various production methods, and a prepolymerized commercially available polymer (as a thermoplastic resin (B)) may be kneaded with fine cellulose, or may be heat-treated in the coexistence of fine cellulose. The raw material monomer of the plastic resin (B) may be polymerized to obtain a resin composition.

When using a pre-polymerized thermoplastic resin, either a method of partially hydrolyzing fine cellulose in advance and then kneading it, or a method of continuously kneading the fine cellulose with the thermoplastic resin while performing partial hydrolysis in a kneader is performed. But it doesn't matter.

In one aspect, the method for producing the resin composition of the present embodiment is
By heating fine cellulose and / or plant fiber in a water-containing state and in a low oxygen concentration atmosphere, a compounding component containing partially hydrolyzed fine cellulose (A) can be obtained, and the compounding component and thermoplasticity can be obtained. Combining with resin (B),
including. The "low oxygen concentration atmosphere" of the present disclosure is an atmosphere in which the oxygen concentration is preferably 18% by volume or less, more preferably 10% by volume or less, still more preferably 5% by volume or less, and particularly preferably 1% by volume or less. be. In one aspect, the compounding component further comprises hemicellulose (C) and / or lignin (D), which is derived from or separately added from the raw material of partially hydrolyzed fine cellulose (A).

As a method for obtaining the partially hydrolyzed fine cellulose (A) in advance, the aqueous dispersion itself of the fine cellulose and / or the raw material of the fine cellulose (for example, plant fiber) or the one obtained by adding an acid, and the pH is There is a method of advancing acid hydrolysis by treating a fine cellulose dispersion having an acidity of 1 or more and 7 or less at room temperature or high temperature. The acid used to acidify the dispersion may be an organic acid, an inorganic acid, or a solid acid. When an acid having an oxidizing ability (for example, nitric acid or halogen oxo acid) is used, the amount of addition is preferably small because it may oxidize fine cellulose to reduce heat resistance and reinforcing effect. Acids with no oxidizing ability or relatively weak acids (dilute hydrochloric acid, dilute sulfuric acid, phosphoric acid, phobic acid, carbonic acid) in that the hydrolysis of the crystalline structure portion can be suppressed to a low level while satisfactorily hydrolyzing the amorphous portion. Inorganic acids such as acetic acid, oxalic acid, citric acid, lactic acid, glutamic acid, aspartic acid, glycine, phenol and other organic acids, ion exchangers (Nafion (registered trademark), Amberlite (registered trademark), etc.), Y-type zeolite , Β-type zeolite, mesoporous silica, solid acid such as sulfonated carbon), and acid hydrolysis under heating is preferable.

Further, partial hydrolysis may be carried out by utilizing an enzymatic reaction instead of acid hydrolysis. Cellulase (specifically, cellobiohydrolase, endoglucanase, or β-glucosidase) can be used as the enzyme, but it is possible to suppress the hydrolysis of the crystal structure portion to a low degree while satisfactorily hydrolyzing the amorphous portion. Endoglucanase is preferred because it can.

The decomposition conditions for hydrolysis using these acids or enzymes can be appropriately selected as long as the fine cellulose is not hydrolyzed to a low aspect ratio.

On the other hand, as a method of partially hydrolyzing fine cellulose in a kneader, the fine cellulose is fed to the kneader in any form selected from an aqueous dispersion, a hydrous cake, and a dry powder and mixed with a thermoplastic resin. There is a way to do it. When fine cellulose is used as a dry powder, an appropriate amount of water is separately introduced into the kneader. The kneader is not limited to the following, but for example, a uniaxial or multiaxial kneading extruder, a roll, a Banbury mixer or the like may be used. Of these, a twin-screw extruder equipped with a decompression device and side feeder equipment is preferable.

Various polymerization reactions can be used as a method for obtaining a resin composition by polymerizing a raw material monomer of a thermoplastic resin in the coexistence of fine cellulose. Examples of the polymerization reaction include radical polymerization, cationic polymerization, anionic polymerization, metathesis polymerization, polycondensation, polyaddition, addition condensation and the like. The fine cellulose may be partially hydrolyzed in advance as described above, or may be partially hydrolyzed continuously and / or simultaneously with the polymerization reaction. A method in which the partial hydrolysis and the polymerization reaction are carried out continuously and / or in parallel is preferable because it contributes to shortening of the manufacturing process and cost saving.

The partial hydrolysis and the production of the resin composition are preferably carried out in a system having a low oxygen concentration atmosphere by substituting with an inert gas such as nitrogen or argon or reducing the pressure, respectively. By partially hydrolyzing and / or producing the resin composition in a low oxygen concentration atmosphere, the thermal decomposition of fine cellulose and the oxidation of the reduced terminal newly generated by the partial hydrolysis are less likely to occur, and the resin composition It is possible to provide a resin composition in which the coloration and reduction of the reinforcing effect are suppressed and the quality variation is small.

Since the resin composition of the present invention can obtain a molded product having good tensile properties and abrasion resistance, it can be used for industrial mechanical parts (for example, electromagnetic device housings, roll materials, transport arms, medical device members, etc.), and general products. Mechanical parts, automobile / railway / vehicle parts (for example, outer panels, chassis, aerodynamic parts, seats, friction materials inside transmissions, etc.), ship parts (for example, hulls, seats, etc.), aviation-related parts (for example, fuselage, main wings, etc.) Tail wings, moving wings, fairings, cowls, doors, seats, interior materials, etc.), spacecraft, artificial satellite parts (motor cases, main wings, structures, antennas, etc.), electronic and electrical parts (for example, personal computer housings, mobile phones, etc.) Housing, OA equipment, AV equipment, telephones, facsimiles, home appliances, toy supplies, etc.), construction / civil engineering materials (for example, reinforcing bar substitute materials, truss structures, cables for suspension bridges, etc.), daily necessities, sports / leisure supplies (for example) For example, golf club shafts, fishing rods, tennis and badminton rackets, etc.), housing members for wind power generation, etc., and containers / packaging members, for example, high-pressure containers filled with hydrogen gas such as those used in fuel cells. Can be a material for.

Further, the resin composition of the present embodiment can be molded in the form of a resin composite such as a resin composite film. For example, a resin composite film is suitable for reinforcing a laminated board in a printed wiring board. In addition, resin composites include, for example, generators, transformers, rectifiers, circuit breakers, insulating cylinders in controllers, insulating levers, arc-extinguishing plates, operating rods, insulating spacers, cases, wind cylinders, end bells, wind blowers, and standard products. Switch boxes, cases, crossbars, insulated shafts, fan blades, mechanical parts, transparent resin substrates, speaker diaphragms, eta diaphragms, TV screens, fluorescent lamp covers, antennas for communication equipment and aerospace, horn covers for electrical products , Radome, case, mechanical parts, wiring board, aircraft, rocket, electronic equipment parts for artificial satellites, railway parts, marine parts, bathtubs, septic tanks, corrosion resistant equipment, chairs, safety caps, pipes, tank lorries, cooling towers, floating It can also be applied to applications such as breakwaters, underground buried tanks, and containers.

Among these, sliding members (for example, bearings, gears, sliding members, etc. in industrial equipment, office equipment, etc.) can exhibit superiority by improving their characteristics compared to existing resin composites. Dynamic parts, household electrical equipment parts, automobile mechanical parts, etc.).

Hereinafter, the present invention will be specifically described with reference to Examples, but the scope of the present invention is not limited to the following Examples. The main measured values of physical properties were measured by the following methods.

(1) Average Fiber Diameter of Fine Cellulose A dispersion liquid of fine cellulose or a redispersion liquid of fine cellulose obtained by dissolving and removing a resin from a resin composition is diluted to a concentration of 0.01% by mass and placed on a silicon wafer. After dropping and drying, 10 randomly selected sites were observed with a scanning electron microscope (SEM) at a magnification of 1000 to 100,000 times according to the fiber diameter of the fine cellulose. In the obtained SEM image, lines in two vertical and horizontal directions forming right angles to each other are drawn, the fiber diameter of the fiber intersecting the line is measured from the enlarged image, and the number of fibers intersecting the line and the fiber diameter of each fiber are measured. Counted. The number average fiber diameter was calculated using the measurement results of two vertical and horizontal series for one image thus obtained. Further, the number average fiber diameter was calculated in the same manner for the other nine SEM images extracted. The results of the images at 10 locations were averaged to obtain the average fiber diameter of the target sample.

(2) Aspect ratio determination of fine cellulose In the same manner as in (1) above, 10 randomly selected SEM observations were performed. In the obtained SEM image, lines in two vertical and horizontal directions forming right angles to each other are drawn, and the fiber length and fiber diameter of the fibers intersecting the lines are measured from the enlarged image, and the number of fibers intersecting the lines and the number of fibers of each fiber are measured. The fiber diameter was counted. The aspect ratio was determined from the obtained fiber length and fiber diameter, and it was determined whether or not fine cellulose having a low aspect ratio was contained. When the aspect ratio is high, it may not be possible to obtain an accurate aspect ratio because the fine cellulose is bent or the entire image does not fit in the image. However, in the resin composition of the present invention, the effect is exhibited if the aspect ratio is high, so it is sufficient if fine cellulose having a low aspect ratio can be observed. The aspect ratio was determined according to the following criteria.
⊚: Fine cellulose having an aspect ratio of 30 or less is not contained in all of the 10 observation areas.
〇: Fine cellulose having an aspect ratio of 30 or less is contained in any of the 10 observation areas.
Δ: Fine cellulose having an aspect ratio of 30 or less is contained in all of the 10 observation areas.

(3) Measurement of Molecular Weight Distribution of Fine Cellulose The measurement of the molecular weight distribution of fine cellulose was performed by gel permeation chromatography (GPC). The dispersion medium is removed from the fine cellulose dispersion or the fine cellulose redispersion obtained by dissolving and removing the resin from the resin composition, the cellulose residue is dissolved in the LiCl-containing dimethylacetamide eluent, and filtered through a PTFE cartridge filter. To prepare a sample solution.
HLC-8120GPC (manufactured by Tosoh), TSKgel guardcolum Super AW-H (4.6 mm ID x 3.5 cm) + Tskgel Super AWM-H (6.0 mm ID x 15 cm) x 2 (both manufactured by Tosoh) ) Was connected, and the peak was detected by the RI detector. As the calibration curve, a linear approximate straight line using a standard pullulan (manufactured by Shodex) was used to determine the molecular weight of the pullulan-equivalent value. The degree of polymerization can also be converted by dividing the molecular weight by the molecular weight of the anhydrous glucose unit (162), which is a monomer unit of cellulose.

Based on the peak top molecular weight of the obtained GPC chart (horizontal axis: molecular weight, vertical axis: distribution value), it is divided into a low molecular weight side and a high molecular weight side, and the integrated values (areas) of each are S1 on the low molecular weight side and high molecular weight. The side was S2, and the amount ratio of the low molecular weight substance (that is, low molecular weight cellulose) and the high molecular weight substance (that is, high molecular weight cellulose) was expressed by the S1 / S2 ratio.

(4) Quantitative analysis of hemicellulose Quantitative analysis of hemicellulose was performed by the following method. A dry sample obtained by removing the dispersion medium from the dispersion liquid of fine cellulose or the redispersion liquid of fine cellulose obtained by dissolving and removing the resin from the resin composition, recovering the cellulose residue, and drying at 105 ° C. The mass was measured by the following method.

The crushed sample obtained by crushing the dried cellulose residue was extracted with an alcohol (ethanol) / benzene mixed solvent) for 6 hours with a Soxhlet extractor, and then extracted with an alcohol (ethanol) / benzene mixed solvent) for another 4 hours. A degreased sample was obtained. To 2.5 g of the defatted sample, 150 mL of distilled water, 1.0 g of sodium chlorite and 0.2 mL of acetic acid were added, and heat treatment was performed at 70 to 80 ° C. for 1 hour. The operation of adding 2 mL and heating at 70 to 80 ° C. for 1 hour was repeated 3 to 4 times until the sample turned white. The obtained sample was filtered, washed with water and acetone, and dried at 105 ° C. to obtain a holocellulose fraction. The mass of this holocellulose fraction was measured.

Subsequently, 25 mL of a 17.5 mass% sodium hydroxide aqueous solution was added to 1.0 g of the holocellulose fraction, and after 3 minutes, the holocellulose fraction was lightly crushed with a glass rod until it became swollen. Allow to stand at 20 ° C., 30 minutes after adding the above sodium hydroxide aqueous solution, add 25 mL of distilled water, stir for exactly 1 minute, leave at 20 ° C. for 5 minutes, and filter with a glass filter to remove the filtrate. Washed until neutral. Further, 40 mL of 10 mass% acetic acid was suction-filtered, and then 1 L of boiling water was suction-filtered and washed, and the sample was dried at 105 ° C. until the mass became constant to obtain an α-cellulose fraction. The mass of this α-cellulose fraction was measured.

From the mass of the holocellulose fraction and the α-cellulose fraction obtained as described above, the hemicellulose content was determined by the following formula.
Holocellulose (%) = holocellulose fraction (g) / sample (anhydrous base) (g) x 100
α-cellulose (%) = α-cellulose fraction (g) / sample (anhydrous base) (g) × 100
Hemicellulose (%) = holocellulose (%) -α-cellulose (%)

(5) Quantitative analysis of lignin Quantitative analysis of lignin was carried out by the following method. To 300 mg of the degreased sample obtained during the above quantitative analysis of hemicellulose, 3 mL of 72 mass% sulfuric acid was added, allowed to stand at 30 ° C. for 1 hour, and then poured into a pressure-resistant bottle (125 mL volume) with 84 mL of distilled water. It was autoclaved at 120 ° C. for 1 hour, filtered through a glass filter before cooling to filter out acid-insoluble lignin, and the filtrate was also recovered. The acid-insoluble lignin was washed with distilled water and dried at 105 ° C., then the mass of the acid-insoluble lignin fraction was measured, and the absorbance of the filtrate was measured with an ultraviolet-visible spectrophotometer.

The content of acid-insoluble lignin and acid-soluble lignin was calculated from the following formula. The total lignin content is calculated by summing these.
Acid-insoluble lignin (%) = acid-insoluble lignin fraction (g) / sample amount (anhydrous base) (g) x 100
Acid-soluble lignin (%) = ((d × v × (As-Ab)) / (a × w)) × 100
Lignin (%) = acid-insoluble lignin (%) + acid-soluble lignin (%)
d: Dilution ratio v: Filtrate constant volume (L)
As: Absorbance of sample solution Ab: Absorbance of blank solution a: Absorbance coefficient of lignin (110 L / g · cm)
w: Sample amount (anhydrous base) (g)

(6) Measurement of Number Average Molecular Weight of Thermoplastic Resin (B) Measurement of number average molecular weight of the thermoplastic resin was performed by gel permeation chromatography (GPC). A known eluent can be used depending on the resin type. Taking a polyamide resin as an example, the thermoplastic resin used as the raw material of the resin composition is dissolved in hexafluoroisopropanol (HFIP), or the solution obtained by dissolving the resin composition in HFIP is filtered by a PTFE cartridge filter. A sample solution was prepared. Hexafluoroisopropanol in which sodium trifluoroacetate was dissolved at 0.1 mol /% was used as an eluent.
HLC-8320GPC (manufactured by Tosoh) with TSKgel guardcolum HHR-L (6mm I.D. x 4cm) + TSKgel-G2000HHR (7.8mm I.D. x 30cm) + TSKgel-G3000HHR (7.8mm I.D. x 30cm) each (Both manufactured by Tosoh) were connected, peaks were detected with an RI detector, and the number average molecular weight of the polymethyl methacrylate conversion value was determined.

(7) Molding conditions / Measurement of mechanical properties The multipurpose test piece is injection-molded under the conditions conforming to ISO294-3 and JIS K6920-2, and the raw material resin (that is, the thermoplastic resin alone) and the resin composition (that is, the fine cellulose-containing resin) are injected. For each of the compositions), the tensile yield strength was measured according to ISO527.
Since the polyamide-based material changes due to moisture absorption, it was stored in an aluminum moisture-proof bag immediately after molding to suppress moisture absorption.

(8) Wear resistance test (coefficient of friction and wear depth)
For the multipurpose test piece obtained under the above molding conditions, a reciprocating friction and wear tester (AFT-15MS type manufactured by Toyo Precision Co., Ltd.) and a SUS304 test piece (sphere with a diameter of 5 mm) were used as the mating material, and the linear velocity was 50 mm. A sliding test was carried out at / sec, a reciprocating distance of 50 mm, a temperature of 23 ° C., and a humidity of 50%. For the friction coefficient, the value at the end of the test with a load of 9.8 N and 10,000 reciprocations was adopted. As for the amount of wear, the amount of wear (wear depth) of the sample after the sliding test was measured using a confocal microscope (OPTELICS (registered trademark) H1200, manufactured by Lasertec Co., Ltd.). The wear depth was the average value of the numerical values measured at n = 4, and was rounded off to the first decimal place. The measurement points were measured at equal intervals of 12.5 mm from the edges of the wear marks. In addition, it was evaluated that the lower the value of the wear depth, the better the wear characteristics.

(9) Coloring of molded product The color tone of the multipurpose test piece obtained under the above molding conditions was visually evaluated.

[Production Example 1] (Preparation of Fine Cellulose Raw Material 1)
After cutting the cotton linter pulp, purified pulp from which impurities have been removed by washing with water is added to pure water so that the solid content ratio becomes 1.5% by mass, and the fiber is highly shortened and made into fibrils by beating. After that, defibrated cellulose was obtained by defibrating with a high-pressure homogenizer (operating pressure: treated 10 times at 85 MPa) at the same concentration. Here, in the beating process, a disc refiner is used, and after processing with a beating blade having a high cutting function (hereinafter referred to as a cutting blade) for 2.5 hours, a beating blade having a high defibration function (hereinafter referred to as a defibrating blade) is used. The mixture was beaten for another 2 hours to obtain a dispersion of the fine cellulose raw material 1.

[Production Example 2] (Preparation of Fine Cellulose Raw Material 2)
Production Example 1 except that the purified pulp from which the cotton linter pulp was cut and then washed with water to remove impurities was further immersed in a 5% potassium hydroxide aqueous solution overnight to remove hemicellulose. In the same manner as in the above, beating and micronization treatment with a high-pressure homogenizer were carried out to obtain a dispersion liquid of the fine cellulose raw material 2.
[Production Example 3] (Preparation of Fine Cellulose Raw Material 3)
In addition to using abaca pulp as a raw material, beating and a micronization treatment with a high-pressure homogenizer were carried out in the same manner as in Production Example 1 to obtain a dispersion liquid of the fine cellulose raw material 3.

[Production Example 4] (Preparation of Fine Cellulose Raw Material 4)
A short fiber raw yarn was used as a raw material, in which the oil of Tencel (registered trademark) cut yarn (3 mm long) supplied by Lenting Fibers was sufficiently removed by washing in water with a surfactant addition system several times. Other than that, beating and micronization treatment with a high-pressure homogenizer were carried out in the same manner as in Production Example 1 to obtain a dispersion liquid of the fine cellulose raw material 4.

[Production Example 5] (Preparation of Fine Cellulose Raw Material 5)
Same as Production Example 1 except that a commercially available DP pulp (average polymerization degree 1600) was cut, hydrolyzed in a 10 mass% hydrochloric acid aqueous solution at 105 ° C. for 5 minutes, and then filtered and washed using an intermediate as a raw material. The mixture was beaten and micronized with a high-pressure homogenizer to obtain a dispersion of the fine cellulose raw material 5.

[Production Example 6] (Preparation of Fine Cellulose Raw Material 6)
According to the method described in Example 1 of Special Table No. 11-513425, finely chopped sea squirt pods are bleached with a solution of sodium hydroxide and sodium chlorite, and stirred with a mixer to obtain a 1% by mass suspension. Obtained. This suspension was treated 15 times at a pressure of 45 MPa using a high-pressure homogenizer (15MR-8TA manufactured by APV GAULIN) to obtain a dispersion liquid of the fine cellulose raw material 6.

[Production Example 7] (Preparation of Fine Cellulose Raw Material 7)
After cutting the cotton linter pulp, refined pulp from which impurities have been removed by washing with water is added to pure water so that the solid content ratio becomes 1.5% by mass, and the pulp is shortened and fibrillated by beating. , A dispersion of the fine cellulose raw material 7 was obtained without performing the high-pressure homogenizer treatment.

[Examples 1 to 12, Comparative Examples 1 to 5]
(Example 1)
A uniform dispersion containing 173 parts by mass of an aqueous dispersion of the fine cellulose raw material 1, 216 parts by mass of a thermoplastic resin monomer (ε-caprolactam), 44 parts by mass of aminocaproic acid, and 0.59 parts by mass of phosphorous acid. Stir and mix with a mixer until it becomes. Subsequently, nitrogen was flowed into a closed reaction vessel to replace the air. The mixed dispersion was gradually heated, and the fine cellulose was partially hydrolyzed while discharging water vapor during the heating, the temperature was raised to 240 ° C., and the mixture was stirred at 240 ° C. for 1 hour to carry out a polymerization reaction.
When the polymerization was completed, the obtained resin composition was dispensed and cut into pellets. The obtained pellets were refined with hot water at 95 ° C. and dried. The injection molding conditions were a cylinder temperature of 250 ° C. and a mold temperature of 70 ° C. Table 1 shows the results of various evaluations.

(Example 2)
A resin composition was produced in the same manner as in Example 1, except that 520 parts by mass of the aqueous dispersion of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Example 3)
A resin composition was produced in the same manner as in Example 1, except that 867 parts by mass of the aqueous dispersion of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Example 4)
A resin composition was produced in the same manner as in Example 1, except that 1733 parts by mass of the aqueous dispersion of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Example 5)
A resin composition was produced in the same manner as in Example 1, except that 2600 parts by mass of an aqueous dispersion of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Example 6)
A resin composition was produced in the same manner as in Example 1, except that 3467 parts by mass of the aqueous dispersion of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Example 7)
A resin composition was produced in the same manner as in Example 1, except that 867 parts by mass of the aqueous dispersion of the fine cellulose raw material 2 was used, and molding and evaluation were performed.

(Example 8)
A resin composition was produced in the same manner as in Example 1, except that 520 parts by mass of the aqueous dispersion of the fine cellulose raw material 3 was treated at 240 ° C. and 5 MPa for 1 minute before use, and molding and evaluation were performed. ..

(Example 9)
A resin composition was produced in the same manner as in Example 1, except that 867 parts by mass of the aqueous dispersion of the fine cellulose raw material 3 was treated at 240 ° C. and 5 MPa for 1 minute before use, and molding and evaluation were performed. ..

(Example 10)
A resin composition was produced in the same manner as in Example 1, except that 867 parts by mass of the aqueous dispersion of the fine cellulose raw material 4 was used, and molding and evaluation were performed.

(Example 11)
A resin composition was produced in the same manner as in Example 4, except that phosphorous acid was not added, and molding and evaluation were performed.

(Example 12)
200 parts by mass of the aqueous dispersion of the fine cellulose raw material 1 and 5 parts by mass of acetic acid were put into an autoclave, and nitrogen was passed through a closed reaction vessel to replace air. The mixed dispersion was heated at 120 ° C. for 3 hours, cooled to room temperature, centrifuged, and washed to obtain a hydrous cake having a solid content concentration of 5% by mass. This step was repeated to obtain 300 parts by mass of a hydrous cake having a solid content concentration of 5% by mass.
A pressure control type liquid injection nozzle is installed in the cylinder 6 of a twin-screw extruder (OMEGA30H, L / D = 60 manufactured by STEER) with 13 cylinder blocks, the cylinder 1 is water-cooled, the cylinder 2 is 80 ° C, and the cylinder. 3 was set to 150 ° C., and cylinders 4 to 13 and dies were set to 250 ° C. The thermoplastic resin PA610 is supplied from the cylinder 1 at a flow rate of 11.4 kg / hour, and the water-containing cake having a solid content concentration of 5% by mass is pumped from the liquid injection nozzle of the cylinder 6 to the extruder at a flow rate of 200 cc / min. I added it. The cylinder 12 was opened to atmospheric pressure and extruded to obtain fine cellulose-containing resin composition pellets. The obtained pellets were refined with hot water at 95 ° C. and dried. The injection molding conditions were a cylinder temperature of 250 ° C. and a mold temperature of 70 ° C. Table 1 shows the results of various evaluations.

(Example 13)
A resin composition was produced in the same manner as in Example 12, except that the thermoplastic resin (PA12) was used, and molding and evaluation were performed.

(Comparative Example 1)
After centrifuging the aqueous dispersion of the fine cellulose raw material 1 to obtain a hydrous cake having a solid content concentration of 5% by mass, a closed planetary mixer (manufactured by Kodaira Seisakusho Co., Ltd., trade name "ACM-5LVT", stirring). The blades are agitated at 70 rpm in a hook type), a warm bath at 40 ° C. is set under a reduced pressure condition of −0.1 MPa, and a vacuum drying treatment is performed at 307 rpm for 5 hours to obtain a dry powder of the fine cellulose raw material 1. rice field. The dry powder and the thermoplastic resin (PA6) were mixed at a ratio of 5:95, melt-kneaded and extruded into strands to produce a resin composition, which was molded and evaluated.

(Comparative Example 2)
A resin composition was produced in the same manner as in Comparative Example 1, except that the dry powder of the fine cellulose raw material 1 and the thermoplastic resin (PA6) having a low average molecular weight were mixed and used at a ratio of 10:90 (mass ratio). Then, molding and evaluation were performed.

(Comparative Examples 3 to 5)
Using commercially available thermoplastic resins (PA6: Comparative Example 3), (PA610: Comparative Example 4), and (PA12: Comparative Example 5) independently, injection molding was performed at a cylinder temperature of 250 ° C. and a mold temperature of 70 ° C. Evaluation was performed.
Table 1 shows the properties of each component and the molded product.

Since the resin composition according to the present invention provides a molded product having excellent tensile properties and abrasion resistance, it provides industrial mechanical parts, general mechanical parts, automobile / railway / vehicle parts, ship parts, aviation-related parts, spacecraft. , Artificial satellite members, electronic / electrical parts, construction / civil engineering materials, daily necessities, sports / leisure goods, wind power generation housing members, containers / packaging members, and the like.

Claims (12)

A method for producing a resin composition, which comprises partially hydrolyzed fine cellulose (A), a thermoplastic resin (B) and hemicellulose (C).
In the partially hydrolyzed fine cellulose (A), a part of the cellulose on the surface layer of the microfibril or the microfibril bundle is hydrolyzed by the step of hydrotreating the microfibril or the microfibril bundle.
A method for producing a resin composition, wherein the mass ratio (C) / (A) of hemicellulose (C) / partially hydrolyzed fine cellulose (A) is 0.001 to 0.2. A method for producing a resin composition, which comprises partially hydrolyzed fine cellulose (A), a thermoplastic resin (B), hemicellulose (C) and lignin (D).
In the partially hydrolyzed fine cellulose (A), a part of the cellulose on the surface layer of the microfibril or the microfibril bundle is hydrolyzed by the step of hydrotreating the microfibril or the microfibril bundle.
A method for producing a resin composition, wherein the mass ratio (D) / (C) of lignin (D) / hemicellulose (C) is 0.001 to 10. The method for producing a resin composition according to claim 1 or 2, wherein the partially hydrolyzed fine cellulose (A) is a fine cellulose fiber having a fiber length / fiber diameter aspect ratio of 30 or more. The partially hydrolyzed fine cellulose (A) has a peak top molecular weight corresponding to a degree of polymerization of 450 or more.
In the partially hydrolyzed fine cellulose (A), when the amount of the low molecular weight component having a molecular weight equal to or lower than the peak top molecular weight is S1 and the amount of the high molecular weight component having a molecular weight exceeding the peak top molecular weight is S2, S1 The method for producing a resin composition according to any one of claims 1 to 3, wherein / S2 is greater than 1.00. The method for producing a resin composition according to claim 4, wherein S1 / S2 is greater than 1.00 and less than or equal to 3.00. The method for producing a resin composition according to any one of claims 1 to 5, wherein the partially hydrolyzed fine cellulose (A) has an average fiber diameter of 4 to 3000 nm. The resin according to any one of claims 1 to 6, wherein the mass ratio (A) / (B) of the partially hydrolyzed fine cellulose (A) / thermoplastic resin (B) is 0.01 to 1. Method for producing the composition. The method for producing a resin composition according to any one of claims 1 to 7, wherein the thermoplastic resin (B) is a polyamide resin. The method for producing a resin composition according to any one of claims 1 to 8, wherein the partially hydrolyzed fine cellulose (A) has no inner layer hydrolyzed in microfibrils or microfibril bundles. Obtaining a resin composition by the method for producing a resin composition according to any one of claims 1 to 9, and molding the resin composition to obtain a slidable member.
A method for manufacturing a slidable member, including. A resin composition comprising partially hydrolyzed fine cellulose (A), a thermoplastic resin (B) and hemicellulose (C).
In the partially hydrolyzed fine cellulose (A), a part of the cellulose on the surface layer of the microfibril or the microfibril bundle is hydrolyzed by hydrotreating the microfibril or the microfibril bundle.
A resin composition having a mass ratio (C) / (A) of hemicellulose (C) / partially hydrolyzed fine cellulose (A) of 0.001 to 0.2. A resin composition comprising partially hydrolyzed fine cellulose (A), a thermoplastic resin (B), hemicellulose (C) and lignin (D).
In the partially hydrolyzed fine cellulose (A), a part of the cellulose on the surface layer of the microfibril or the microfibril bundle is hydrolyzed by hydrotreating the microfibril or the microfibril bundle.
A resin composition having a mass ratio (D) / (C) of lignin (D) / hemicellulose (C) of 0.001 to 10.