JP2019203108A - 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 comprising fine cellulose having a partially hydrolyzed structure, and particularly to a resin composition capable of giving a molded article having good sliding properties.

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

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

  Therefore, in recent years, cellulose having a low environmental load has been used as a new reinforcing material for resins.

It is known that cellulose has a high elastic modulus comparable to an aramid fiber and a linear expansion coefficient lower than that of glass fiber as its simple substance properties. Further, the true density is as low as 1.56 g / cm ^3, and glass (density 2.4 to 2.6 g / cm ³ ) or talc (density 2.7 g / cm ³ ) used as a reinforcing material for general thermoplastic resins. Compared with ³ ), the material is overwhelmingly light.

  Cellulose is not only made from trees, but also from hemp, cotton, kenaf, cassava and so on. Furthermore, bacterial cellulose represented by Nata de Coco is also known. There are a large amount of natural resources as raw materials on the earth, and for this effective use, a technique that utilizes cellulose as a filler in a resin is attracting attention.

  In order to fully exhibit the characteristics of cellulose, it is necessary to create a fine and uniform dispersion state in the thermoplastic resin. Cellulose obtained from natural resources is physically and / or chemically combined with hemicellulose or lignin to form a strong cell wall. A step of taking out the cellulose fibers is performed. Cellulose fibers that have been fibrillated to the nanometer order of less than 1 micron are called CNF (cellulose nanofibers), and are pulps obtained by pretreatment such as cooking, selection, and bleaching on plant-derived natural resources. From raw materials, mechanical defibration methods such as high-pressure homogenizer treatment, microfluidizer treatment, underwater collision, ball mill and disk mill treatment, and chemical treatments such as TEMPO oxidation and sulfate esterification are used for low energy defibration. It is known that it forms a highly dispersed state and network at a level called fine nano-dispersion in water.

  The thermoplastic resin and cellulose used for general purposes often have poor affinity due to the difference in surface free energy, and since the interfacial adhesion between CNF and the thermoplastic resin is low, the characteristics cannot often be fully exhibited. On the other hand, a method using a modified cellulose nanofiber chemically modified to modify the surface state of cellulose is known (Patent Document 1).

JP 2017-171698 A

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

  In addition, a method of obtaining modified cellulose nanofibers by adsorbing counterionic additives in water to ionized modified cellulose nanofibers is known, but heat resistance is reduced in ionized modified cellulose, Cellulose nanofibers may undergo thermal decomposition in the process of being kneaded with a resin at a high temperature, failing to exhibit the original reinforcing effect, and may cause unstable quality, equipment troubles, and the like.

  The present invention solves the above-described problems of the prior art, uses a CNF filler that has good interface adhesion with a resin, and has reduced problems of environmental impact and physical properties due to a chemical modification process. It aims at providing the resin composite which can give the resin composite excellent in durability, and its molded object.

As a result of diligent studies to solve the above problems, the present inventors have found that a resin composition containing partially hydrolyzed cellulose and further containing a specific compound can solve the above problems, thereby forming the present invention. It came to.
That is, the present invention includes the following aspects.

[1] A resin composition comprising finely hydrolyzed fine cellulose (A) and a thermoplastic resin (B).
[2] The resin composition according to 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 an aspect ratio of fiber length / fiber diameter of 30 or more.
[4] The partially hydrolyzed fine cellulose (A) has a peak top molecular weight corresponding to a polymerization degree 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 Embodiments 1 to 3, wherein / S2 is greater than 1.00.
[5] The resin composition according to aspect 4, wherein the S1 / S2 is greater than 1.00 and 3.00 or less.
[6] The resin composition according to any one of the above aspects 1 to 5, wherein the average fiber diameter of the partially hydrolyzed fine cellulose (A) is 4 to 3000 nm.
[7] The mass ratio (A) / (B) of partially hydrolyzed fine cellulose (A) / thermoplastic resin (B) is 0.01 to 1, according to any one of the above aspects 1 to 6. 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 in any one of 1-8.
[10] The resin composition according to any one of the above aspects 1 to 9, wherein the thermoplastic resin (B) is a polyamide-based resin.
[11] A method for producing a resin composition according to any one of the above aspects 1 to 10,
Obtaining a blended component containing finely hydrolyzed fine cellulose (A) by heating fine cellulose and / or plant fiber in an atmosphere containing water and an oxygen concentration of 18% by volume or less; and Combining an ingredient and the thermoplastic resin (B);
Including a method.
[12] A slidable member, which is a molded body 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 reduced problems of environmental load and physical properties due to a chemical modification process is used, and a resin composite having excellent wear resistance and durability is obtained. The resin composition which can be provided, and the resin composite which is the molded object can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

<Resin composition>
In one embodiment, the resin composition includes a partially hydrolyzed fine cellulose (A) and a thermoplastic resin (B). In one aspect, the resin composition comprises finely 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 used as a raw material include natural cellulose and regenerated cellulose.

  Natural cellulose includes wood pulp obtained from wood species (hardwood or conifer), non-wood pulp obtained from non-wood species (bamboo, hemp fiber, bagasse, kenaf, linter, etc.), and refined pulps (refined linters). ) Etc. can be used. As non-wood pulp, cotton-derived pulp including 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 respectively cotton lint, cotton linter, hemp-based abaca (eg, Ecuadorian or Filipino 1), sisal, bagasse, kenaf, bamboo, straw, banana stalk, etc., and is preferably a refined pulp obtained through a purification process such as delignification by digestion, a bleaching process, and the like. In addition, seaweed-derived cellulose can also be used.

  Regenerated cellulose is a substance obtained by regenerating natural cellulose by dissolving or crystal swelling (mercelization) treatment, and is equivalent to a lattice spacing of 0.73 nm, 0.44 nm, and 0.40 nm by particle beam diffraction. This refers to a β-1,4-linked glucan (glucose polymer) having a molecular arrangement that gives a crystal diffraction pattern (cellulose II type crystal) with a corner as the apex. In the regenerated cellulose, in the X-ray diffraction pattern, an X-ray diffraction pattern in which the range of 2θ ranges from 0 ° to 30 ° has one peak at 10 ° ≦ 2θ <19 ° and two peaks at 19 ° ≦ 2θ ≦ 30 °. With a peak. Examples of regenerated cellulose include rayon, cupra, and tencel. Since it is easy to make a fiber having a fiber diameter exceeding 100 nm from the regenerated cellulose, the regenerated cellulose may be preferable from the viewpoint of dispersibility in the resin. As the raw material for the fine cellulose, cupra and tencel having a high molecular orientation in the fiber axis direction are particularly preferred from the viewpoint of easy miniaturization. Furthermore, a cut yarn of regenerated cellulose fiber, a cut yarn of cellulose derivative fiber, or the like can be used as a raw material. Moreover, you may mix and use a natural cellulose and a regenerated cellulose as a raw material.

  It is generally known that cellulose fibers include regularly arranged crystal structure portions and irregular amorphous structure portions. Usually, about 40 cellulose molecules form microfibrils having a width of about 4 to 5 nm by intermolecular hydrogen bonding, and a plurality of microfibrils gather to form a bundle having a width of about 15 nm or more. A cellulose nanofiber is a fiber in which the bundle is further gathered and defibrated up to a state having a fiber diameter of several tens to several hundreds of nanometers to a microfibril equivalent. Cellulose fibers are defibrated to increase the surface area and increase the interface when they are composited with a resin, so that the effect of improving mechanical properties (reinforcing effect) increases. However, in the case of fine cellulose fibers close to microfibrils that have been further defibrated, decomposition from the surface is likely to occur due to heating in the step of compositing 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, resulting in poor design properties. Is preferably at most 3000 nm, more preferably at most 2000 nm, further preferably at most 1500 nm, particularly preferably at most 1000 nm. The average fiber diameter is a value measured by the method described in the [Example] section of the present disclosure.

  Properties of cellulose such as high elastic modulus and low linear expansion coefficient are mainly attributed to the crystal structure. Since the cellulose molecules in the crystal structure part are strongly hydrogen-bonded to each other, they are hardly hydrolyzed, but the amorphous part is easily hydrolyzed. In crystalline cellulose obtained by cleaving amorphous cellulose molecules by acid hydrolysis and refining to a degree of polymerization of about 200 to 300, the aspect ratio of length / thickness is about several tens at the maximum, and cellulose nanowhiskers and cellulose It is called nanocrystal. When it is miniaturized to this size, when it is made into a composite with a resin, it is difficult to form a network due to the interaction between cellulose nanocrystals in the resin, so that a reinforcing effect is also hardly exhibited. In addition, 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 one in which at least a part of the amorphous part is only hydrolyzed, and the cellulose nanocrystal having a low aspect ratio is not decomposed. The aspect ratio of length / thickness (fiber length / fiber diameter) of the partially hydrolyzed fine cellulose (A) is preferably 30 or more, more preferably 50 or more, and still more 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 inclusion of fine cellulose having a lower aspect ratio than the above preferred range I can confirm. In the resin composition, it is preferable that the amount of fine cellulose cut to such a low aspect ratio is small, but it may be present within a range where 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 is considered as follows from the results of macroscale analysis. When cellulose is hydrolyzed by, for example, heating under neutral to weak acidic conditions in the presence of water, at least a part of the amorphous part 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, while hardly containing fine cellulose having a low aspect ratio in morphological observation. In other words, in the partially hydrolyzed cellulose, in the microfibril or microfibril bundle, the hydrolysis is not substantially caused in the inner layer, and the hydrolysis of the surface layer is only partially, so that the cellulose has a high aspect ratio. Present as fine cellulose.

  The partially hydrolyzed fine cellulose (A) can be analyzed by various methods generally used for analyzing cellulose. The molecular weight distribution is preferably measured by gel permeation chromatography (GPC). The molecular weight distribution may be monomodal with one peak, bimodal with two peaks, or in rare cases with more than two peaks, but the peak top molecular weight (ie, the peak of the largest peak). The molecular weight is divided into a low molecular weight side and a high molecular weight side. When the peak top molecular weight is divided by the molecular weight 162 of anhydroglucose unit which is a monomer structure of cellulose, the degree of polymerization can be converted. 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 equal to or higher than the above degree of polymerization, excessive progress of partial hydrolysis is suppressed, the content of fine cellulose having a low aspect ratio equivalent to that of cellulose nanocrystal is small, and heat resistance is good. In the molecular weight measurement, the amount of low molecular weight component having a molecular weight equal to or lower than the peak top molecular weight (cumulative area strength) is S1, and the amount of high molecular weight component having a molecular weight exceeding the peak top molecular weight (cumulative area strength) is S2. The lower limit of the ratio is preferably more than 1.00, more preferably 1.05 or more, further preferably 1.10 or more, still more preferably 1.15 or more, and particularly preferably 1.20 or more. When S1 / S2 is higher than these ratios, good tensile strength, friction coefficient and wear depth of the resin composite can be obtained by the partially hydrolyzed fine cellulose (A). 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 less than or equal to these ratios, thermal decomposition and performance degradation due to heating when the resin composite is kneaded can be suppressed.

  The reason why the partially hydrolyzed fine cellulose (A) exhibits an effect superior to that of normal (that is, not partially hydrolyzed) fine cellulose is presumed as follows. By hydrolyzing the amorphous part of cellulose, a reducing end (position 1 of the glucose unit) and a non-reducing end (position 4 of the glucose unit) are newly generated. Among these, the reducing end is in an equilibrium state between the hemiacetal group and the aldehyde group, but this aldehyde group is present in the main chain and / or side chain and / or terminal of the thermoplastic resin, and is an amino group or a carboxy group. React with functional groups such as hydroxy groups to form covalent bonds. As a result, the interfacial adhesion between the fine cellulose and the thermoplastic resin is strengthened.

[Hemicellulose (C) and lignin (D)]
In one embodiment, the resin composition further comprises hemicellulose (C) and / or lignin (D) (more typically both hemicellulose (C) and lignin (D)). Usually, in the fine cellulose derived from a plant, a polysaccharide generically called hemicellulose and an aromatic compound generically called lignin remain between microfibrils and between microfibril bundles. In the present invention, it is preferable that these components are not removed completely in the production process of fine cellulose, but remain in a suitable range. Hemicellulose is a polysaccharide composed of sugars such as mannan and xylan, and plays a role of bonding between microfibrils by hydrogen bonding to cellulose. Moreover, since the solubility parameter (SP value) of hemicellulose is on the more hydrophobic side than cellulose, it is considered that hemicellulose has an effect of relaxing the SP value difference between the thermoplastic resin and fine cellulose.

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

  Lignin is a compound having an aromatic ring and is known to be covalently bonded to hemicellulose in the plant cell wall. 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 more preferably 0.01 or more in terms of mass ratio (D) / (C) to hemicellulose (C). 1 or more is more preferable, 10 or less is preferable, 5 or less is more preferable, and 3 or less is more preferable. Lignin is a more hydrophobic compound than hemicellulose, and is considered to have an effect of better mitigating 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-mentioned range because it induces a decrease in heat resistance and a color change associated therewith in the resin composite.

The amount of hemicellulose (C) can be adjusted to a desired amount by applying a purification treatment to a natural wood raw material with a high hemicellulose content, or a raw material with a low hemicellulose content was used. In such a case, it can be adjusted to a desired amount by adding hemicellulose obtained by extraction 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.
The amount of lignin (D) can be adjusted to a desired amount by refining a natural wood raw material with a high lignin content, or a raw material with a low lignin content can be used. When used, it can be adjusted to a desired amount by adding lignin obtained by extraction from another raw material. At this time, the structure of the lignin terminal or the like 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., or an amorphous resin having a glass transition temperature in the range of 100 to 250 ° C.

  The melting point of the crystalline resin here means the peak top of the endothermic peak that appears when the temperature is raised from 23 ° C. at a rate of 10 ° C./min using a differential scanning calorimeter (DSC). Refers to temperature. When two or more endothermic peaks appear, the peak top temperature of the endothermic peak on the highest temperature side is indicated. 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 which is once heated to a temperature condition of melting point + 20 ° C. or higher, melted the resin, and then cooled to 23 ° C. at a temperature lowering rate of 10 ° C./min.

  In addition, the glass transition temperature of the amorphous resin referred to here is when measured at an applied frequency of 10 Hz while increasing 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, the peak top temperature of the peak on the highest temperature side is indicated. The measurement frequency at this time is desirably measured at least once every 20 seconds in order to improve measurement accuracy. The method for preparing the measurement sample is not particularly limited, but from the viewpoint of eliminating the influence of molding distortion, it is desirable to use a cut piece of a hot press molded product, and the size (width and thickness) of the cut piece is as much as possible. A smaller value is desirable from the viewpoint of heat conduction.

  The thermoplastic resin (B) includes polyamide resin, polyester resin, polyacetal resin, polycarbonate resin, polyacrylic resin, polyphenylene ether resin (polyphenylene ether is modified by blending or graft polymerization with other resins) Modified polyphenylene ether), polyarylate resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, polyketone resin, polyphenylene ether ketone resin, polyimide resin, polyamideimide resin, polyetherimide Resin, polyurethane resin, polyolefin resin (for example, α-olefin (co) polymer), various ionomers and the like.

  Preferred specific examples of the thermoplastic resin (B) include high-density polyethylene, low-density polyethylene (for example, linear low-density polyethylene), polypropylene, polymethylpentene, cyclic olefin-based resin, poly-1-butene, poly-1-pentene, Polymethylpentene, ethylene / α-olefin copolymer, ethylene / butene copolymer, EPR (ethylene-propylene copolymer), modified ethylene / butene copolymer, EEA (ethylene-ethyl acrylate copolymer), modified EEA, modified EPR, modified EPDM (ethylene-propylene-diene terpolymer), ionomer, α-olefin copolymer, modified IR (isoprene rubber), modified SEBS (styrene-ethylene-butylene-styrene copolymer) , Halogenated isobutylene-paramethylstyrene copolymer, Tylene-acrylic acid-modified product, ethylene-vinyl acetate copolymer, and acid-modified product thereof, (ethylene and / or propylene) and (unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) copolymer, ( Polyolefin, conjugated diene and vinyl aromatic hydrocarbon obtained by metallizing at least a part of the carboxyl group of a copolymer of (ethylene and / or propylene) and (unsaturated carboxylic acid and / or unsaturated carboxylic ester) Block copolymers, hydrides of block copolymers of conjugated dienes and vinyl aromatic hydrocarbons, copolymers of other conjugated diene compounds and nonconjugated olefins, natural rubber, various butadiene rubbers, various styrene-butadiene copolymers Polymer rubber, isoprene rubber, butyl rubber, isobutylene and p-methylstyrene copolymer bromide, halogen Butyl rubber, acrylonitrile butadiene rubber, chloroprene rubber, 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 rubber, polysulfide rubber, silicone rubber, fluorine rubber, urethane rubber, polyvinyl chloride, polystyrene, polyacrylic ester, polymethacrylic ester, acrylic, acrylonitrile Acrylonitrile copolymer, acrylonitrile / butanediene / styrene (ABS) resin, acrylonitrile / styrene (AS) resin, cellulose resin such as cellulose acetate, chloride Nil / ethylene copolymer, vinyl chloride / vinyl acetate copolymer, ethylene / vinyl acetate copolymer, and ethylene / saponified like vinyl acetate copolymer.

  These may be used individually by 1 type and may use 2 or more types together. When using 2 or more types together, you may use as a polymer alloy. Moreover, what modified | denatured the above-mentioned thermoplastic resin by the at least 1 sort (s) of compound chosen from unsaturated carboxylic acid, its acid anhydride, or its derivative (s) can also be used.

  Among these, from the viewpoint of heat resistance, moldability, designability and mechanical properties, polyolefin resin, polyamide resin, polyester resin, polyacetal resin, polyacrylic resin, polyphenylene ether resin, polyphenylene sulfide resin and Although the mixture of 2 or more types of these is mentioned, it is not limited to these. Among these, polyolefin resins, polyamide resins, polyester resins, polyacetal resins, and the like are more preferable resins from the viewpoint of handleability and cost.

  The polyolefin resin is a polymer obtained by polymerizing monomer units containing olefins (for example, α-olefins). Specific examples of the polyolefin resin are not particularly limited, but ethylene (co) heavy 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. Polypropylene (co) polymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene exemplified by polymer, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, etc. -Copolymers of α-olefins and other monomer units represented by glycidyl methacrylate copolymers and the like.

  The most preferable polyolefin-based resin here includes polypropylene. In particular, polypropylene having a melt mass flow rate (MFR) measured at 230 ° C. and a load of 21.2 N in accordance with ISO 1133 is 3 g / 10 min or more and 30 g / 10 min or less is preferable. The lower limit value of MFR is more preferably 5 g / 10 minutes, still more preferably 6 g / 10 minutes, and most preferably 8 g / 10 minutes. The upper limit is more preferably 25 g / 10 minutes, still more preferably 20 g / 10 minutes, and most preferably 18 g / 10 minutes. The MFR desirably does not exceed the upper limit from the viewpoint of improving the toughness of the composition, and desirably does not exceed the lower limit from the viewpoint of the fluidity of the composition.

  Moreover, in order to improve the affinity with cellulose, an acid-modified polyolefin resin can also be suitably used. The acid can be appropriately selected from maleic acid, fumaric acid, succinic acid, phthalic acid and anhydrides thereof, and polycarboxylic acids such as citric acid. Among these, maleic acid or an anhydride thereof is preferable because it easily increases the modification rate. There are no particular restrictions on the modification method, but a method of melting and kneading the resin by heating it to the melting point or higher in the presence / absence of peroxide is common. As the polyolefin resin to be acid-modified, all of the above-mentioned polyolefin resins can be used, but polypropylene can be preferably used.

  The acid-modified polyolefin resin may be used alone, but is more preferably used by mixing with an unmodified polyolefin resin in order to adjust the modification rate of the composition. For example, when using a mixture of unmodified polypropylene and acid-modified polypropylene, the ratio of the acid-modified polypropylene to the total propylene is preferably 0.5% by mass to 50% by mass. A more preferred lower limit is 1% by mass, still more preferably 2% by mass, still more preferably 3% by mass, particularly preferably 4% by mass, and most preferably 5% by mass. A more preferred upper limit is 45% by mass, still more preferably 40% by mass, still 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 is preferable, and in order to maintain the ductility as a resin, the upper limit is preferable.

  The melt mass flow rate (MFR) measured at 230 ° C. under a load of 21.2 N in accordance with the preferred ISO 1133 of acid-modified polypropylene is 50 g / 10 min or more in order to increase the affinity with the cellulose interface. preferable. A more preferred lower limit is 100 g / 10 minutes, even more preferred is 150 g / 10 minutes, and most preferred is 200 g / 10 minutes. Although there is no upper limit in particular, 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 of being easily present at the interface between cellulose and resin.

  The polyamide-based resin preferable as the thermoplastic resin is not particularly limited, but polyamide 6, polyamide 11, polyamide 12, etc. obtained by polycondensation reaction of lactams; 1,6-hexanediamine, 2-methyl-1,5- Pentanediamine, 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-xylylenediamine, and the like, butanedioic acid, pentanedioic acid, hexanedioic acid, Heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, benzene-1,2-dicarboxylic acid, ben Polyamides obtained as copolymers with dicarboxylic acids such as cyclohexane-1,3-dicarboxylic acid, benzene-1,4 dicarboxylic acid, etc., cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, etc. 6, polyamide 6,10, polyamide 6,11, polyamide 6,12, polyamide 6, T, polyamide 6, I, polyamide 9, T, polyamide 10, T, polyamide 2M5, T, polyamide MXD, 6, polyamide 6, C, polyamide 2M5, C, and the like; and copolymers obtained by copolymerizing them (polyamide 6, T / 6, I as an example).

  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, polyamide 6, C, polyamide 2M5, C The alicyclic polyamide is more preferable.

  Although there is no restriction | limiting in particular in the terminal carboxyl group density | concentration of a polyamide-type resin, A lower limit is preferable in it being 20 micromol / g, More preferably, it is 30 micromol / g. The upper limit of the terminal carboxyl group concentration is preferably 150 μmol / g, more preferably 100 μmol / g, and still more preferably 80 μmol / g.

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

  As a method for adjusting the terminal group concentration of the polyamide-based resin, a known method can be used. For example, diamine compound, monoamine compound, dicarboxylic acid compound, monocarboxylic acid compound, acid anhydride, monoisocyanate, monoacid halide, monoester, monoalcohol, etc. The method of adding the terminal regulator which reacts with a terminal group to a polymerization liquid is mentioned.

  Examples of terminal regulators that react with terminal amino groups include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid. Aliphatic monocarboxylic acids such as cycloaliphatic carboxylic acids; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid Carboxylic acid; 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 in terms of reactivity, stability of the sealing end, price, etc. And one or more terminal regulators selected from the group consisting of benzoic acid and acetic acid is most preferred.

  Examples of the terminal regulator that reacts with the terminal carboxyl group include aliphatic amines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine. Examples include monoamines; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine, and any mixture thereof. Among these, one or more terminals selected from the group consisting of butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline in terms of reactivity, boiling point, stability of the sealing end, price, etc. A modifier is preferred.

The concentration of the amino terminal group and the carboxyl terminal group is preferably determined from the integral value of the characteristic signal corresponding to each terminal group by ¹ H-NMR in terms of accuracy and simplicity. Specifically, the method described in Japanese Patent Application Laid-Open No. 7-228775 is recommended as a method for obtaining the concentration of these end groups. When this method is used, deuterated trifluoroacetic acid is useful as a measurement solvent. In addition, the number of ¹ H-NMR integrations is required to be at least 300 scans even when measured with an instrument having sufficient resolution. In addition, the concentration of end groups can be measured by a titration measurement method as described in JP-A-2003-055549. However, in order to reduce the influence of mixed additives, lubricants and the like as much as possible, quantification by ¹ H-NMR is more preferable.

  Polyester resins preferred as thermoplastic resins are not particularly limited, but include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene succinate (PBS), polybutylene succinate adipate ( PBSA), polybutylene adipate terephthalate (PBAT), polyarylate (PAR), polyhydroxyalkanoic acid (PHA) (polyester resin comprising 3-hydroxyalkanoic acid), polylactic acid (PLA), polycarbonate (PC), etc. 1 type (s) or 2 or more types can be used. Among these, more preferable polyester resins include PET, PBS, PBSA, PBT, and PEN, and more preferably, PBS, PBSA, and PBT.

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

  Polyacetal resins that are preferable as thermoplastic resins are generally homopolyacetals that use formaldehyde as a raw material, and copolyacetals that contain trioxane as the main monomer, for example, 1,3-dioxolane 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 comonomer component (for example, 1,3-dioxolane) is preferably in the range of 0.01 to 4 mol%. A more preferred lower limit of the comonomer component amount is 0.05 mol%, more preferably 0.1 mol%, and particularly preferably 0.2 mol%. A more preferred upper limit is 3.5 mol%, still 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, the lower limit is preferably 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 terminal that easily reacts with the newly produced reducing terminal aldehyde in the partially hydrolyzed fine cellulose (A).

  The number average molecular weight Mn of the thermoplastic resin (B) is not particularly limited as long as it can be processed by a molding method such as injection molding, extrusion molding, or blow molding generally used when molding a resin composition. When the number average molecular weight Mn of the thermoplastic resin (B) is low, it is known that the mechanical properties and impact resistance of the resin composition are lowered. However, the resin composition of the present invention is a partially hydrolyzed fine material. Since it has good adhesion to cellulose (A), it can also be applied to thermoplastic resins 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 13000, less than 12000, less than 11,000, and less than 10,000, good mechanical strength can be obtained. The said number average molecular weight is a value calculated | required by polymethyl methacrylate conversion using gel permeation chromatography (GPC).

  In the resin composition, the mass ratio (A) / (B) of the amount of the partially hydrolyzed fine cellulose (A) to the amount of the thermoplastic resin (B) depends on the partially hydrolyzed fine cellulose (A). From the viewpoint of obtaining a good reinforcing effect, preferably 0.01 or more, more preferably 0.02 or more, still more preferably 0.03 or more, from the viewpoint of forming a molded article well, 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]
In the resin composition of the present invention, as other components, for example, an antioxidant; a crystal nucleating agent; a compatibilizing agent; a plasticizer; a colorant; a fragrance; a pigment; a flow control agent; Additives such as agents, ultraviolet absorbers, ultraviolet dispersants, deodorants, bactericides, and flame retardants may be blended. The content ratio of the optional additive may be appropriately set within a range in which the desired effect of the present invention is not impaired.

<Method for producing resin composition>
The resin composition of the present invention can be produced by various production methods. A commercially available polymer (as a thermoplastic resin (B)) polymerized in advance may be kneaded with fine cellulose, or in the presence of fine cellulose, The raw material monomer of the plastic resin (B) may be polymerized to form a resin composition.

  When using a prepolymerized thermoplastic resin, either a method of kneading fine cellulose after partial hydrolysis, or a method of kneading with a thermoplastic resin continuously while performing partial hydrolysis in a kneader It doesn't matter.

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

  As a method for obtaining the partially hydrolyzed fine cellulose (A) in advance, it is obtained by adding an aqueous dispersion of fine cellulose and / or a raw material of fine cellulose (for example, plant fiber) itself, or an acid, and pH There is a method of proceeding acid hydrolysis by treating a fine cellulose dispersion having an acidity of from 1 to 7 at normal temperature or high temperature. The acid used to make the dispersion acidic may be an organic acid or an inorganic acid, or a solid acid may be used. When an acid having an oxidizing ability (for example, nitric acid or halogen oxo acid) is used, it is preferable that the amount added is small because fine cellulose may be oxidized to reduce heat resistance and reinforcing effect. In terms of being able to suppress hydrolysis of the crystal structure portion to a low level while hydrolyzing the amorphous portion well, there is no oxidizing ability or a relatively weak acid (dilute hydrochloric acid, dilute sulfuric acid, phosphoric acid, phosphorous acid, carbonic acid) 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, sulfonated carbon and other solid acids), and the acid hydrolysis is preferably performed under heating.

  Moreover, you may perform partial hydrolysis using an enzyme reaction instead of acid hydrolysis. Cellulase (specifically, cellobiohydrolase, endoglucanase, or β-glucosidase) can be used as the enzyme, but it can suppress hydrolysis of the crystal structure portion to a low level while favorably hydrolyzing the amorphous portion. Endoglucanase is preferable because it can be used.

  Degradation conditions for hydrolysis using these acids or enzymes can be appropriately selected within the range in which fine cellulose is not hydrolyzed to a low aspect ratio.

  On the other hand, as a method of partially hydrolyzing the fine cellulose in the kneader, the fine cellulose is fed to the kneader in any form selected from an aqueous dispersion, a water-containing cake, and a dry powder and mixed with the 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 kneading machine is not limited to the following, and for example, a uniaxial or multi-axial kneading extruder, a roll, a Banbury mixer or the like may be used. Among 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 of obtaining a resin composition by polymerizing raw material monomers of a thermoplastic resin in the presence of fine cellulose. Examples of the polymerization reaction include radical polymerization, cationic polymerization, anionic polymerization, metathesis polymerization, polycondensation, polyaddition, and addition condensation. As described above, the fine cellulose may be partially hydrolyzed in advance, or may be partially hydrolyzed continuously and / or concurrently with the polymerization reaction. A method in which the partial hydrolysis and the polymerization reaction are performed continuously and / or in parallel is preferable because it contributes to shortening of the manufacturing process and cost reduction.

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

  Since the resin composition of the present invention can provide a molded article having good tensile properties and wear resistance, industrial machine parts (for example, electromagnetic equipment casings, roll materials, transport arms, medical equipment members, etc.), general Machine parts, automobile / railway / vehicle parts (eg, outer panels, chassis, aerodynamic members, seats, friction materials inside transmissions, etc.), ship members (eg, hulls, seats, etc.), aviation related parts (eg, fuselage, main wings, etc.) Tail wing, moving wing, fairing, cowl, door, seat, interior material, etc.), spacecraft, satellite member (motor case, main wing, structure, antenna, etc.), electronic / electrical parts (eg personal computer housing, mobile phone) Cases, OA equipment, AV equipment, telephones, facsimiles, home appliances, toy supplies, etc.), construction and civil engineering materials (for example, reinforcing steel substitute materials, truss structures, suspension bridge cables, etc. ), Household goods, sports / leisure goods (eg golf club shafts, fishing rods, tennis and badminton rackets, etc.), housing members for wind power generation, etc., and containers / packaging members such as fuel cells It can be a material for a high pressure vessel filled with hydrogen gas or the like.

  Moreover, the resin composition of this embodiment can be shape | molded in the form of resin composites, such as a resin composite film. For example, a resin composite film is suitable for reinforcing a laminated board in a printed wiring board. Other 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 tunnels, end bells, wind sinks, standard Switch boxes, cases, crossbars, insulation 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 , Radomes, cases, mechanical parts, wiring boards, aircraft, rockets, satellite electronic equipment parts, railway parts, marine parts, bathtubs, septic tanks, corrosion-resistant equipment, chairs, safety caps, pipes, tank trucks, cooling towers, floats It can also be applied to uses such as breakwaters, underground tanks, and containers.

  Among these, slidable members (for example, bearings, gears, sliding members, etc. in industrial equipment, office equipment, etc.) can exhibit superiority due to improved characteristics compared to existing resin composites. Dynamic use parts, household electrical equipment parts, automobile mechanism parts, etc.).

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, the scope of the present invention is not limited to the following Example. The main measured values of physical properties were measured by the following methods.

(1) Average fiber diameter of fine cellulose A fine cellulose dispersion or a fine cellulose re-dispersion obtained by dissolving and removing a resin from a resin composition is diluted to a concentration of 0.01% by mass on a silicon wafer. After dripping and drying, 10 points randomly selected were observed with a scanning electron microscope (SEM) at a magnification equivalent to 10,000 to 100,000 times according to the fiber diameter of fine cellulose. In the obtained SEM image, lines in two directions, which are perpendicular to each other, are drawn, and the fiber diameters of the fibers that intersect the lines are measured from the enlarged image, and the number of fibers that intersect the lines and the fiber diameter of each fiber I counted. The number average fiber diameter was calculated using the measurement results of two series of length and width for one image. Further, the number average fiber diameter was calculated in the same manner for the other 9 extracted SEM images. The results of 10 images were averaged to obtain the average fiber diameter of the target sample.

(2) Determination of aspect ratio of fine cellulose As in (1) above, 10 randomly selected SEMs were observed. In the obtained SEM image, two vertical and horizontal lines perpendicular to each other are drawn, and the fiber length and fiber diameter of the fibers crossing the lines are measured from the enlarged image, and the number of fibers crossing the line and the respective fibers 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, an accurate aspect ratio may not be required because fine cellulose is bent or does not fit entirely in the image. However, in the resin composition of the present invention, if the aspect ratio is high, the effect is exhibited, and it is only necessary to observe fine cellulose having a low aspect ratio. The aspect ratio was determined according to the following criteria.
A: All of the 10 observation areas do not contain fine cellulose having an aspect ratio of 30 or less.
◯: Fine cellulose having an aspect ratio of 30 or less is included in any of the 10 observation areas.
Δ: Fine cellulose having an aspect ratio of 30 or less is included in all of the 10 observation areas.

(3) Measurement of molecular weight distribution of fine cellulose The molecular weight distribution of fine cellulose was measured by gel permeation chromatography (GPC). The dispersion medium is removed from the fine cellulose dispersion or the fine cellulose re-dispersion obtained by dissolving and removing the resin from the resin composition, and the cellulose residue is dissolved in the LiCl-containing dimethylacetamide eluent and filtered through a PTFE cartridge filter. Thus, a sample solution was prepared.
To HLC-8120GPC (manufactured by Tosoh Corporation), TSKgel guardcolumn Super AW-H (4.6 mm ID x 3.5 cm) + Tskel super AWM-H (6.0 mm ID x 15 cm) x 2 (both manufactured by Tosoh Corporation) ) And a peak was detected with an RI detector. For the calibration curve, a primary approximate straight line using standard pullulan (manufactured by Shodex) was used to obtain the molecular weight of the pullulan converted value. In addition, it can also convert into a polymerization degree by remove | dividing this molecular weight by the anhydrous glucose unit molecular weight (162) which is a monomer unit of a cellulose.

  The obtained GPC chart (horizontal axis: molecular weight, vertical axis: distribution value) is divided into a low molecular weight side and a high molecular weight side based on the peak top molecular weight, and the integrated values (areas) are S1 and high molecular weight on the low molecular weight side. On the side, as S2, the ratio between the low molecular weight substance (ie, low polymerization degree cellulose) and the high molecular weight substance (ie, high polymerization degree cellulose) was expressed as S1 / S2 ratio.

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

  A pulverized sample obtained by pulverizing the dried cellulose residue was extracted with a Soxhlet extractor with an alcohol (ethanol) / benzene mixed solvent) for 6 hours, and then extracted with an alcohol (ethanol) / benzene mixed solvent) for another 4 hours. A degreased sample was obtained. Distilled water (150 mL), sodium chlorite (1.0 g) and acetic acid (0.2 mL) were added to degreased sample (2.5 g), 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 was decolorized 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% by mass aqueous sodium hydroxide solution was added to 1.0 g of the holocellulose fraction, and after 3 minutes, the mixture was lightly crushed with a glass rod until 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 through a glass filter. Washed until neutral. Furthermore, 40 mL of 10% by mass acetic acid was suction filtered, and then 1 L of boiling water was suction filtered and the sample washed was dried at 105 ° C. until the mass became constant, thereby obtaining an α-cellulose fraction. The mass of this α-cellulose fraction was measured.

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

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

The contents of acid-insoluble lignin and acid-soluble lignin were calculated from the following formula. These are summed to determine the total lignin content.
Acid insoluble lignin (%) = acid insoluble lignin fraction (g) / sample amount (anhydrous basis) (g) × 100
Acid soluble lignin (%) = ((d × v × (As−Ab)) / (a × w)) × 100
Lignin (%) = acid insoluble lignin (%) + acid soluble lignin (%)
d: dilution factor v: filtrate constant volume (L)
As: Absorbance of sample solution Ab: Absorbance of blank solution a: Absorption coefficient of lignin (110 L / g · cm)
w: Sample amount (anhydrous basis) (g)

(6) Number average molecular weight measurement of thermoplastic resin (B) The number average molecular weight measurement 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 through a PTFE cartridge filter. A sample solution was prepared. As the eluent, hexafluoroisopropanol in which 0.1 mol /% sodium trifluoroacetate was dissolved was used.
HSK-8320GPC (manufactured by Tosoh Corporation) TSKgel guardcolumn HHR-L (6 mm ID × 4 cm) + TSKgel-G2000HHR (7.8 mm ID × 30 cm) + TSKgel-G3000HHR (7.8 mm ID × 30 cm) (Both manufactured by Tosoh Corporation) were connected, the peak was detected with an RI detector, and the number average molecular weight in terms of polymethyl methacrylate was determined.

(7) Measurement of molding conditions and mechanical properties Multi-purpose test pieces are injection-molded under conditions based on ISO 294-3 and JIS K6920-2, and raw material resin (that is, thermoplastic resin alone) and resin composition (that is, resin containing fine cellulose) About each of the composition), the tensile yield strength was measured based on 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 (friction coefficient and wear depth)
The multi-purpose test piece obtained under the above molding conditions is a reciprocating friction and wear tester (AFT-15MS type manufactured by Toyo Seimitsu Co., Ltd.), and a SUS304 test piece (sphere having a diameter of 5 mm) as a mating material, and a linear velocity of 50 mm. / Sec, reciprocation distance 50 mm, temperature 23 ° C., humidity 50%. As the coefficient of friction, values at the end of the test with a load of 9.8 N and a reciprocation count of 10,000 were adopted. The amount of wear was measured by using a confocal microscope (OPTELICS (registered trademark) H1200, manufactured by Lasertec Co., Ltd.). The wear depth was the average of the values measured at n = 4 and rounded off to the first decimal place. The measurement location was carried out at an equal interval of 12.5 mm from the end of the wear scar. The wear depth was evaluated to be superior in wear characteristics when the numerical value was lower.

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

[Production Example 1] (Preparation of fine cellulose raw material 1)
After the cotton linter pulp is cut, purified pulp, which has been washed with water to remove impurities, is added to pure water so that the solid content is 1.5% by mass, and the fibers are highly shortened and fibrillated by beating. Then, defibrated cellulose was obtained by defibrating with a high pressure homogenizer (operating pressure: 10 times treatment at 85 MPa) at the same concentration. Here, in the beating process, a disc refiner is used, and a beating blade having a high defibrating function (hereinafter referred to as a defibrating blade) is processed for 2.5 hours with a beating blade having a high cutting function (hereinafter referred to as a cutting blade). The resulting mixture was further beaten for 2 hours to obtain a dispersion of 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 washed with water to remove impurities was further immersed in a 5% aqueous potassium hydroxide solution overnight to remove hemicellulose was used as a raw material. In the same manner as above, beating and refining with a high-pressure homogenizer were carried out to obtain a dispersion of fine cellulose raw material 2.
[Production Example 3] (Preparation of fine cellulose raw material 3)
Except for using Abaca pulp as a raw material, beating and refining treatment with a high-pressure homogenizer were carried out in the same manner as in Production Example 1 to obtain a dispersion of fine cellulose raw material 3.

[Production Example 4] (Preparation of fine cellulose raw material 4)
Short fiber yarn that was sufficiently dropped by washing the oil agent of Tencel (registered trademark) cut yarn (3 mm length) supplied by Lenzing Fibers with water in a surfactant addition system was used as a raw material. Other than that, the beating and the refinement | miniaturization process by a high voltage | pressure homogenizer were implemented similarly to manufacture example 1, and the dispersion liquid of the fine cellulose raw material 4 was obtained.

[Production Example 5] (Preparation of fine cellulose raw material 5)
A commercial DP pulp (average polymerization degree 1600) was cut and hydrolyzed in a 10% by weight aqueous hydrochloric acid solution at 105 ° C. for 5 minutes, followed by filtration and washing. The fine cellulose raw material 5 was obtained by refining and refinement with a high-pressure homogenizer.

[Production Example 6] (Preparation of fine cellulose raw material 6)
According to the method described in Example 1 of JP-T-11-513425, the finely chopped squirt sheath is bleached with sodium hydroxide and sodium chlorite solution 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 of fine cellulose raw material 6.

[Production Example 7] (Preparation of fine cellulose raw material 7)
After cutting the cotton linter pulp, the purified pulp, which has been washed with water to remove impurities, is added to pure water so that the solid content is 1.5% by mass, and the fibers are 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 10]
Example 1
173 parts by mass of an aqueous dispersion of 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 with a mixer until mixing. Subsequently, air was replaced by flowing nitrogen into the sealed reaction vessel. This mixed dispersion was gradually heated, and partial hydrolysis of fine cellulose was performed while discharging water vapor in the middle of 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 resin composition obtained 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 1 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 1 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 1 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 the aqueous dispersion of 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 1 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 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 for 1 minute under the conditions of 240 ° C. and 5 MPa, and molded and evaluated. .

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 for 1 minute under the conditions of 240 ° C. and 5 MPa, and molded and evaluated. .

(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 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 an aqueous dispersion of the fine cellulose raw material 1 and 5 parts by mass of acetic acid were charged into an autoclave, and nitrogen was passed into the sealed reaction vessel to replace the air. The mixed dispersion was heated at 120 ° C. for 3 hours, cooled to room temperature, centrifuged and washed to obtain a water-containing cake having a solid content concentration of 5 mass%. This process 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 (STEMER OMEGA30H, L / D = 60) with 13 cylinder blocks, the cylinder 1 is water-cooled, the cylinder 2 is 80 ° C., the cylinder 3 was set to 150 ° C, the cylinders 4 to 13 and the die 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 fed from the liquid injection nozzle of the cylinder 6 to the extruder at a flow rate of 200 cc / min. Added. The cylinder 12 was opened at atmospheric pressure and extruded to obtain pellets containing fine cellulose-containing resin composition. 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)
A resin composition was produced in the same manner as in Example 1 except that 173 parts by mass of the aqueous dispersion 5 of the fine cellulose raw material 5 was used, and molding and evaluation were performed.

(Comparative Example 2)
A resin composition was produced in the same manner as in Example 1 except that 52 parts by mass of the aqueous dispersion of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Comparative Example 3)
A resin composition was produced in the same manner as in Example 1 except that 10400 parts by mass of the aqueous dispersion 1 of the fine cellulose raw material 1 was used, and molding and evaluation were performed.

(Comparative Example 4)
The aqueous dispersion of the fine cellulose raw material 1 was centrifuged to obtain a water-containing cake having a solid content concentration of 5% by mass, and then a sealed planetary mixer (trade name “ACM-5LVT”, manufactured by Kodaira Seisakusho Co., Ltd.) The blade is a hook type) and is stirred at 70 rpm. Under a reduced pressure condition of -0.1 MPa, a 40 ° C. warm bath is set, and a reduced pressure drying treatment is performed at 307 rpm for 5 hours to obtain a dry powder of the fine cellulose raw material 1 It was. The dry powder and the thermoplastic resin (PA6) were mixed at a ratio of 5:95, melt-kneaded, extruded into a strand shape to produce a resin composition, and molded and evaluated.

(Comparative Example 5)
A resin composition was produced in the same manner as in Example 1 except that 1300 parts by mass of an aqueous dispersion of fine cellulose raw material 6 was used, and molding and evaluation were performed.

(Comparative Example 6)
A resin composition is produced in the same manner as in Comparative Example 4, except that the dry powder of the fine cellulose raw material 1 and the thermoplastic resin (PA6) having a low average molecular weight are mixed at a ratio of 10:90 (mass ratio). Then, molding and evaluation were performed.

(Comparative 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 fine cellulose raw material 7 was used, and molding and evaluation were performed.

(Comparative Examples 8 to 10)
Commercially available thermoplastic resins (PA6: Comparative Example 8), (PA610: Comparative Example 9), and (PA12: Comparative Example 10) were each used for injection molding 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 body.

  Since the resin composition according to the present invention gives a molded article having excellent tensile properties and wear resistance, industrial machine parts, general machine parts, automobile / railway / vehicle parts, ship members, aviation-related parts, spacecraft It can be suitably applied to artificial satellite members, electronic / electric parts, construction / civil engineering materials, daily necessities, sports / leisure products, casing members for wind power generation, containers / packaging members, and the like.

Claims (12)

  A resin composition comprising a partially hydrolyzed fine cellulose (A) and a thermoplastic resin (B).   The resin composition according to claim 1, further comprising hemicellulose (C).   The resin composition according to claim 1 or 2, wherein the partially hydrolyzed fine cellulose (A) is a fine cellulose fiber having an aspect ratio of fiber length / fiber diameter of 30 or more. The partially hydrolyzed fine cellulose (A) has a peak top molecular weight corresponding to a polymerization degree 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 claims 1 to 3, wherein / S2 is greater than 1.00.   The resin composition according to claim 4, wherein the S1 / S2 is larger than 1.00 and 3.00 or less.   The resin composition according to any one of claims 1 to 5, wherein the average fiber diameter of the partially hydrolyzed fine cellulose (A) is 4 to 3000 nm.   Resin according to any one of claims 1 to 6, wherein the partially hydrolyzed fine cellulose (A) / thermoplastic resin (B) mass ratio (A) / (B) is 0.01-1. Composition.   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 as described in any one of 1-7.   The said resin composition contains hemicellulose (C) and lignin (D), and mass ratio (D) / (C) of lignin (D) / hemicellulose (C) is 0.001-10. The resin composition as described in any one of these.   The resin composition according to any one of claims 1 to 9, wherein the thermoplastic resin (B) is a polyamide-based resin. It is the manufacturing method of the resin composition as described in any one of Claims 1-10,
Obtaining a blended component containing finely hydrolyzed fine cellulose (A) by heating fine cellulose and / or plant fiber in an atmosphere containing water and an oxygen concentration of 18% by volume or less; and Combining an ingredient and the thermoplastic resin (B);
Including a method.   The slidable member which is a molded object of the resin composition as described in any one of Claims 1-10.