JPWO2019163873A1 - Disentangling aid for hydrophobized cellulosic fibers, method for producing resin composition using the same, and molded article - Google Patents

Abstract

A part of the hydrogen atoms of the hydroxyl group of the cellulosic fiber has the general formula (A): Ra-CO- (in the formula, Ra may have an alkyl group having 1 to 4 carbon atoms or an electron-donating substituent). An acyl group represented by a phenyl group), or general formula (B): Rb- (wherein, Rb is an alkyl group having 1 to 4 carbon atoms, a 2-hydroxyethyl group, a 2-hydroxypropyl group, A defibration aid for defibrating a hydrophobized cellulosic fiber assembly, which is represented by a 2-cyanoethyl group or an allyl group) and is substituted with an alkyl group which may have a substituent, The following general formula (1): R1-CO-N(R2)-R3(1) (In the formula, R1 and R3 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or Or R1 and R3 together represent an alkylene group having 3 to 11 carbon atoms, and R2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an acyl group having 2 to 4 carbon atoms). A defibration aid containing the represented amide compound as a main component.

Description

  The present invention relates to a defibration aid for hydrophobized cellulosic fibers, a method for producing a resin composition using the defibration aid, and a molded article.

  Microfibrillated cellulosic fibers (also referred to herein as "cellulose nanofibers" or "CNFs") are plant fibers or pulp for papermaking that have been defibrated to a micro or nano level thickness. Light weight and high strength.

  Research is being conducted to improve the original properties of the resin, such as strength properties, by combining CNF with the resin.

  Here, the strength characteristics of the composite containing the fiber and the resin are largely dependent on the thickness of the fiber contained in the resin, or the affinity between the fiber and the resin and the dispersibility of the fiber in the resin. Therefore, a method of fibrillating a cellulose fiber aggregate to make it into microfibrils, a method of chemically modifying CNF to make it hydrophobic in order to improve the affinity and dispersibility with the resin to be composited, etc. have been studied. ing.

  As a method for defibrating the cellulose fiber aggregate, a mechanical method (a grinder, a ball mill, a high-speed homogenizer, a defibration method by radiating a jet water stream, etc.) is known.

  Regarding the defibration of chemically modified cellulose fibers, the following methods are known together with the defibration method of non-chemically modified cellulose fibers (for example, Patent Documents 1 to 4).

  Patent Document 1 discloses a non-chemically modified or chemically modified plant-derived fiber aggregate having a lignin content of 0 to 5% by weight and a wide variety of liquid substances (water, halogenated hydrocarbons having 2 to 10 carbon atoms, heteroatoms). A CNF or a chemically modified CNF is disclosed in which a mixture with a hydrocarbon having 3 to 20 carbon atoms which may contain C2, carbon dioxide in a supercritical state, etc.) is stirred at a high speed of about 1000 to 50000 rpm. ..

  Patent Document 2 discloses a wide variety of organic solvents (aromatic hydrocarbons, aprotic polar solvents, alcohol solvents, ketone solvents, glycol ether solvents) containing composite raw materials (at least one of resin and resin precursor). And non-chemically modified or chemically modified cellulose fibers dispersed in a halogen solvent, etc.), defibration treatment (defibration treatment by a media mill such as a beads mill, defibration (micronization) treatment by jetting, high-pressure homogenizer) Defibration treatment by a rotary defibration method such as, or defibration treatment by ultrasonic treatment) to produce the organic solvent dispersion of CNF or chemically modified CNF containing the composite raw material is disclosed. There is.

  Patent Document 3 discloses a wide variety of organic solvents (aromatic hydrocarbons, aprotic polar solvents, alcohol solvents) having a specific viscosity (1.0 mPa·S or more) and a refractive index (1.40 or more). Defibration treatment (defibration treatment by media mill such as bead mill, squirt) to non-chemically modified or chemically modified cellulose fibers dispersed in single, mixed solvent of ketone solvent, ether solvent, glycol ether solvent, etc. Fibrillation (micronization) treatment, fibrillation treatment by rotary fibrillation method such as high-pressure homogenizer, or ultrasonic treatment) to produce an organic solvent dispersion of CNF or chemically modified CNF. There is.

  Patent Document 4 discloses a composition containing a chemically modified CNF and a thermoplastic resin, in which a chemically modified cellulose fiber is defibrated in a melt-kneaded product while melt-kneading a specific chemically modified cellulose fiber and a thermoplastic resin. A method of manufacturing is disclosed.

JP 2010-216021 JP International publication WO2011/125801 JP2013-36035 JP 2016-176052

  An object of the present invention is to provide a defibration aid that promotes the defibration property of a hydrophobized cellulosic fiber aggregate, and a resin composition containing the hydrophobized and microfibrillated cellulosic fibers using the defibration aid. The present invention provides an efficient production method thereof, and a fiber reinforced molded article having excellent strength characteristics, which is formed from the composition.

  As a result of intensive studies by the inventors, a specific defibration aid which is effective for defibrating a hydrophobized cellulosic fiber assembly having a specific chemical structure was found, and the above-mentioned object was achieved based on the finding, Was completed.

The present invention relates to the following defibration aid, a method for producing a resin composition, and a molded article.
Item 1.
A part of the hydrogen atoms of the hydroxyl group of the cellulosic fiber has the general formula (A): Ra-CO- (wherein Ra has an alkyl group having 1 to 4 carbon atoms or an electron donating substituent). Or a general formula (B): Rb- (in the formula, Rb is an alkyl group having 1 to 4 carbon atoms, 2-hydroxyethyl group, 2-hydroxypropyl). Group, a 2-cyanoethyl group or an allyl group), which is a defibration aid for defibrating a hydrophobized cellulosic fiber assembly substituted with an alkyl group which may have a substituent. hand,
The following general formula (1):
^{R 1 -CO-N (R 2} ) -R 3 (1)
(In the formula, R ¹ and R ³ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R ¹ and R ³ are taken together to form a group having 3 to 11 carbon atoms. An alkylene group, wherein R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an acyl group having 2 to 4 carbon atoms) as a main component. ..
Item 2.
The amide compound is N,N-dimethylacetamide, N,N-dimethylformamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, δ-valerolactam, N-methyl-δ-valerolactam, ε-caprolactam, N. The defibration aid according to item 1, which is at least one selected from the group consisting of -methyl-ε-caprolactam, N-acetyl-ε-caprolactam, undecanelactam, and laurolactam.
Item 3.
The amide compound is selected from the group consisting of N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, undecanelactam and laurolactam. The defibration aid according to item 1, which is at least one kind.
Item 4.
The defibration according to Item 1, wherein the amide compound is at least one selected from the group consisting of N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and ε-caprolactam. Auxiliary agent.
Item 5.
The defibration aid is at least selected from the group consisting of talc, clay, zeolite, aluminum oxide, calcium carbonate, titanium oxide, silica, magnesium oxide, mica, lithium chloride, N-methylmorpholine N-oxide and urea. The defibration auxiliary agent in any one of said claim|item 1 containing the defibration auxiliary agent of 1 type.
Item 6.
In the defibration aid, hydrogen atoms of a part of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (wherein Ra is an alkyl group having 1 to 4 carbon atoms, or an electron donating group). A phenyl group which may have a substituent is shown.) The defibration aid for defibrating a hydrophobized cellulosic fiber assembly substituted with an acyl group represented by The defibration aid according to any one of the above.
Item 7.
The defibration aid is a defibration aid for defibrating a hydrophobized cellulosic fiber assembly in which hydrogen atoms of some hydroxyl groups of the cellulosic fiber are substituted with an acyl group having 2 to 5 carbon atoms. The defibration aid according to any one of the above items 1 to 5.
Item 8.
The defibration aid is a defibration aid for defibrating a hydrophobized cellulosic fiber assembly in which hydrogen atoms of some hydroxyl groups of the cellulosic fiber are substituted with acetyl groups, the above items 1 to The defibration aid according to any one of 5 above.
Item 9.
Item 9. The defibration aid according to any one of Items 1 to 8, wherein the hydrophobized cellulose fiber aggregate defibrated by the defibration aid is a plant-derived cellulose fiber aggregate.
Item 10.
Item 10. The defibration aid according to any one of items 1 to 9 above, wherein the hydrophobized cellulosic fiber aggregate defibrated by the defibration aid is a plant-derived lignocellulose fiber aggregate.
Item 11.
(1) By using the defibration aid according to any one of items 1 to 10 above, hydrogen atoms of a part of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (in the formula, Ra represents an alkyl group having 1 to 4 carbon atoms, or a phenyl group which may have an electron donating substituent.), or an acyl group represented by the general formula (B): Rb-(formula). Rb represents an alkyl group having 1 to 4 carbon atoms, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-cyanoethyl group or an allyl group, and may have a substituent. The first step of defibrating the hydrophobized cellulosic fiber aggregate substituted with, to produce a microfibrillated hydrophobized cellulosic fiber,
(2) including a second step of mixing the microfibrillated hydrophobized cellulosic fibers obtained in the first step with a resin,
A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber and a resin.
Item 12.
The defibration aid according to any one of items 1 to 10 above, wherein some of the hydrogen atoms of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (wherein Ra is a carbon number of 1 to 4). Represents an alkyl group or a phenyl group which may have an electron-donating substituent), or an acyl group represented by the general formula (B): Rb- (wherein Rb has 1 carbon atom). ~4 alkyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2-cyanoethyl group or allyl group), which is substituted with an alkyl group which may have a substituent. A step of mixing the fiber-based fiber assembly and the resin, and defibrating the hydrophobized cellulose-based fiber assembly according to any one of the above items 1 to 10 during the mixing operation to microfibrillate the fiber.
A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber and a resin.
Item 13.
(1) The defibration aid according to any one of the above items 1 to 10, the hydrogen atoms of a part of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (wherein Ra is the number of carbon atoms. An alkyl group of 1 to 4 or a phenyl group which may have an electron-donating substituent, or an acyl group represented by the general formula (B): Rb- (wherein Rb is A C1-C4 alkyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-cyanoethyl group or an allyl group), which may have a substituent and is substituted with an alkyl group. Hydrophobic cellulosic fiber aggregates, and a resin are mixed, a first step of fibrillating the hydrophobized cellulosic fiber aggregates during the mixing operation to form microfibrils,
(2) a second step of removing the defibration aid from the mixture of the defibration aid, the microfibrillated hydrophobized cellulosic fibers and the resin obtained in the first step,
A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber and a resin.
Item 14.
The microfibrillated hydrophobized cellulosic fiber, resin and phase further mixed with a compatibilizing agent in the first step or the second step of the above item 11, the process of the above item 12 or the first step of the above item 13. A method for producing a resin composition containing a solubilizer.
Item 15.
Item 15. The method for producing a resin composition according to any one of Items 11 to 14, wherein the resin is one kind or two or more kinds of thermoplastic resins.
Item 16.
The thermoplastic resin is polyamide, polyolefin, aliphatic polyester, aromatic polyester, polyacetal, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate-ABS alloy (PC-ABS alloy) and modified polyphenylene. Item 16. The method for producing a resin composition according to Item 15, which is one kind or two or more kinds selected from the group consisting of ether (m-PPE).
Item 17.
A molded article comprising the resin composition produced by the production method according to any one of items 11 to 16 above.

  The defibration aid of the present invention can favorably promote the defibration of a cellulosic fiber aggregate hydrophobized with a specific chemical modification group into a microfibrillated state. Therefore, the defibration aid of the present invention is useful as a defibration aid for defibrating the specific hydrophobized cellulosic fiber aggregate.

  The chemically modified and microfibrillated cellulosic fiber (chemically modified MFC) produced by defibrating with the defibration aid of the present invention is hydrophobized by a specific chemical modifying group. Therefore, the affinity with the thermoplastic resin is high. Therefore, this chemically modified MFC can be easily mixed with the thermoplastic resin and dispersed in the melt-kneaded composition in a fine state in a uniform or nearly uniform state. As a result, the molded body made of the melt-kneaded composition produced by the production method of the present invention has excellent mechanical strength characteristics. Further, since the specific hydrophobized cellulosic fiber aggregate is easily microfibrillated by using the defibration aid of the present invention, the melt-kneaded product containing the chemically modified MFC according to the production method of the present invention. Can be efficiently obtained.

It is an electron microscope observation image of AcNUKP manufactured in Manufacturing Example 1. 5 is a schematic diagram illustrating the manufacturing method of Example 1. FIG. 3 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 1. 5A to 5C are schematic diagrams illustrating a manufacturing method according to a second embodiment. 3 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 2. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 3. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 4. FIG. 7 is a schematic diagram illustrating a manufacturing method of Example 3; 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 3. FIG. 7 is a schematic diagram illustrating a manufacturing method of Example 4. 4 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 4. FIG. 9 is a schematic diagram illustrating a manufacturing method of Example 5. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 5. FIG. 9 is a schematic diagram illustrating a manufacturing method of Example 6; 7 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 6. FIG. 9 is a schematic diagram illustrating a manufacturing method of Example 7. 7 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 7. FIG. 9 is a schematic diagram illustrating a manufacturing method of Example 8. 9 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 8. 7 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 7. 9 is a schematic diagram illustrating a manufacturing method of Comparative Example 8. FIG. 9 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 8. FIG. 10 is a schematic diagram illustrating a manufacturing method of Example 9. 9 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 9. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 9. FIG. 13 is a schematic diagram illustrating a manufacturing method of Example 10. 9 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 10. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 10. FIG. 13 is a schematic diagram illustrating a manufacturing method of Example 11. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 11. 7 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 11. FIG. 11 is a schematic diagram illustrating a manufacturing method of Example 12. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 12. 7 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Comparative Example 12. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 13. FIG. 14 is a schematic diagram illustrating a manufacturing method of Example 14. 5 is a polarization microscope observation image (left) and an electron microscope observation image (right) of fibers in a sample produced from the composition produced by the method of Example 14.

1. Description of Terms and Abbreviations Each of the following terms used herein has the following meaning.

  The cellulosic fiber means a fiber containing cellulose and/or lignocellulose, which is derived from a plant, is derived from a microorganism, is derived from an alga, or is derived from a subphylum Clinicoidea (ascidian).

  Lignocellulose is a complex hydrocarbon polymer (natural polymer mixture) that constitutes the cell wall of trees, and is known to be composed mainly of polysaccharides cellulose, hemicellulose and lignin which is an aromatic polymer. .. In the present invention, the lignocellulose means a substance composed of cellulose, hemicellulose and lignin regardless of the lignin content, and whether or not there is a chemical bond between cellulose, hemicellulose and/or lignin. ..

  Pulp is obtained by separating plant-derived cellulosic fibers from whole plants or parts of plants such as wood, bamboo, rice straw, and cotton, and is a fiber aggregate containing cellulose, hemicellulose, and/or lignocellulose (derived from plants. Means pulp). Further, a cellulose fiber aggregate derived from a microorganism (pulp derived from a microorganism) separated from a mixture of cellulose produced by the microorganism and a bacterial cell of a microorganism, a cellulose fiber aggregate separated from an alga (pulp derived from an alga), and a tail rope. Animal means a cellulose fiber aggregate (squirt-derived pulp) separated from subphylum algae.

  Lignopulp means a pulp containing lignocellulose.

  A chemically modified microfibrillated cellulosic fiber (chemically modified MFC) means a chemically modified and microfibrillated cellulosic fiber. Here, “chemical modification” means that a substituent (chemical modification group) is introduced in place of the hydrogen atom of the hydroxyl group of the sugar chain constituting the cellulose fiber (the hydroxyl group is chemically modified). ..

  In the present specification, microfibrillation does not mean that the diameters of the respective fibers are all on the order of nanometers, but the diameters of the fibers are on the order of nanometers, or the fibers present inside or on the surface of the fibers are nanosized. Means to be ordered. Therefore, a fiber whose fiber diameter is defibrated to the nano order, a fiber whose surface is defibrated to the nano order even if the diameter of the thickest part of the fiber is the nano order or more (for example, several μm), and A fiber in which these fibers are mixed is also interpreted as a microfibrillated fiber.

  By composite is meant a composition that includes a matrix and something other than a matrix. When a resin is used as the matrix and fibers are used for other materials, it is called a resin-fiber composite, and may be called a resin composite or a fiber composite. In addition, a specific fiber name may be used for the fiber, and a specific polymer name (a unique name for the resin or a generic name for the resin such as a thermoplastic resin) may be used for the resin. Therefore, a composition containing a thermoplastic resin as a matrix and a chemically modified MFC is referred to as a thermoplastic resin-chemically modified MFC composite, and may be simply referred to as a thermoplastic resin composite or a chemically modified MFC composite. .. Then, in the production of the composition according to the present invention, kneading treatment or mixing treatment of the resin and the chemically modified MFC, the chemically modified cellulosic fiber or the chemically modified cellulosic fiber aggregate (chemically modified pulp) is referred to as “compositing”. Also called.

The following abbreviations used herein have the following meanings.
Acl: Acyl group Alkyl: Alkyl group Ac: Acetyl group Bz: Benzoyl group LP: Ligno pulp AcP: Pulp in which some hydrogen atoms of the hydroxyl groups of the cellulose-based fibers in the pulp are acetylated AcPF: One of the cellulose fibers derived from plants In which a hydrogen atom of a hydroxyl group of a part is acetyl MFC: microfibrillated cellulose-based fiber Acyl (A) MFC: a part of hydrogen atoms of a hydroxyl group of the cellulose-based fiber is an acyl group represented by the general formula (A) Acylated and microfibrillated fiber Alkyl (B) MFC: a part of the hydrogen atoms of the hydroxyl groups of the cellulosic fiber is an alkyl group which may have a substituent represented by the general formula (B). Alkylated and microfibrillated fibers

2. Disentanglement aid The present invention is that the hydrogen atoms of a part of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (in the formula, Ra is an alkyl group having 1 to 4 carbon atoms, or electron donation). Of a phenyl group which may have a volatile substituent) (hereinafter, sometimes referred to as "acyl group (A)") or a general formula (B): Rb- (formula Rb represents an alkyl group having 1 to 4 carbon atoms, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-cyanoethyl group or an allyl group, and may have a substituent. A defibration aid for defibrating a hydrophobized cellulosic fiber assembly substituted with (hereinafter, also referred to as “alkyl group (B) which may have a substituent”),
The following general formula (1):
^{R 1 -CO-N (R 2} ) -R 3
(In the formula, R ¹ and R ³ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R ¹ and R ³ are taken together to form an alkylene having 3 to 11 carbon atoms. R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an acyl group having 2 to 4 carbon atoms. The defibration aid of the present invention).

  The defibration aid of the present invention is a hydrophobized cellulosic fiber assembly in which some hydrogen atoms of the hydroxyl groups of the cellulosic fiber are substituted with an acyl group (A) or an alkyl group (B) that may have a substituent. In the defibration process of the body (hereinafter collectively referred to as “the defibration raw material”), the defibration raw material has an MFC having the same substituents as those of the defibration raw material (these are abbreviated as “the chemically modified MFC”). ) Is encouraged to be disentangled.

In the general formula (1): R ¹ —CO—N(R ² )—R ³ , R ¹ and R ³ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R ¹ and R ³ together represent an alkylene group having 3 to 11 carbon atoms.

As the alkyl group having 1 to 4 carbon atoms in R ¹ and R ³ , a linear alkyl group (methyl, ethyl, n-propyl, and n-butyl) and a branched alkyl group (isopropyl and tert-butyl) ) Is mentioned. Of these, a methyl group, an ethyl group, and an n-propyl group are preferable.

Examples of the alkylene group having 3 to 11 carbon atoms formed by R ¹ and R ³ together include trimethylene, tetramethylene, pentamethylene, decamethylene and the like, and 3 to 5 carbon atoms and 9 to 11 carbon atoms. Is preferred. In particular, since an amide compound having an alkylene group having 3, 5, 10 and 11 carbon atoms (lactam) (generic name: lactam) is easily available on the market, R ¹ and R ³ are formed together to form an amide compound having ³ , 5 Preferred are 10 and 11 alkylene groups.

Examples of the alkyl group having 1 to 3 carbon atoms in R ² include a linear alkyl group (methyl, ethyl, and n-propyl) and a branched alkyl group (isopropyl). Of these, a methyl group is preferred.

Examples of the acyl group having 2 to 4 carbon atoms in R ² include acetyl and propionyl. Of these, acetyl is preferred.

  As the amide compound represented by the general formula (1), specifically, N,N-dimethylacetamide, N,N-dimethylformamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, δ-valerolactam, Examples thereof include N-methyl-δ-valerolactam, ε-caprolactam, N-methyl-ε-caprolactam, N-acetyl-ε-caprolactam, undecanelactam and laurolactam.

  Among these amide compounds, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, undecanelactam and laurolactam are preferable.

  More preferred amide compounds are N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, ε-caprolactam and laurolactam, and the most preferred amide compound is ε-caprolactam.

  The above amide compounds can be used as a defibration aid of the present invention by mixing two or more kinds.

  In the defibration aid of the present invention, in addition to the amide compound described above, at least one additive selected from the group consisting of talc, clay, zeolite, aluminum oxide, lithium chloride, N-methylmorpholine N-oxide and urea ( The present defibration adjunct) can be included.

  The addition of the defibration auxiliary agent further facilitates the defibration of the defibration raw material. The defibration auxiliary agent of the present invention may be used at the same time as the defibration aid of the present invention or by being added to the defibration raw material before or after the defibration aid of the present invention.

  When the defibration auxiliary agent is added, the mixing ratio of the defibration auxiliary agent and the defibration auxiliary agent is 0.001 to 0.5 parts by mass with respect to 1 part by mass of the defibration auxiliary agent. , And preferably 0.01 to 0.3 parts by mass.

3. The Disentanglement Raw Material The present disentanglement raw material will be described below.

  The defibrating material is a hydrophobized cellulosic fiber assembly in which some of the hydrogen atoms of the hydroxyl groups of the cellulosic fiber are substituted with an acyl group (A) or an alkyl group (B) that may have a substituent. Is.

  In the preparation of the defibrating material used in the present invention (the defibrating material), a cellulosic fiber aggregate derived from a plant, a microorganism, an algae, or a subphylum Caudate (ascidian) is used. be able to. Among these, the plant-derived cellulosic fiber aggregate is preferable because it can be easily obtained in a large amount.

  Examples of raw materials for plant-derived cellulosic fiber aggregates include wood, bamboo, hemp, jute, kenaf, cotton, beet, agricultural waste products, waste paper, and woven cloth. Among these, the cellulose-based fiber aggregate derived from wood (also referred to as wood pulp) is preferable because it is easily available.

  Wood pulp includes one that does not contain lignin and one that contains lignin (that is, also referred to as a lignocellulosic fiber aggregate or ligno pulp). Any of these can be used for the production of the defibrating raw material of the present case. From the viewpoint of manufacturing cost, ligno pulp is preferable.

  Examples of wood that is a raw material of wood pulp include wood derived from softwood such as Sitka spruce, pine (Todomatsu, Japanese red pine), cedar and cypress, and hardwood such as eucalyptus and acacia. The plant-derived pulp obtained from these is preferably used for the production of the defibrating raw material of the present case.

  Wood pulp can be obtained by treating a vegetable raw material by a method such as a mechanical pulping method, a chemical pulping method, or a combination of a mechanical pulping method and a chemical pulping method. Examples of such pulp include kraft pulp and mechanical pulp (MP). Examples of the kraft pulp include unbleached kraft pulp of softwood (NUKP), unbleached kraft pulp exposed to oxygen of softwood (NOKP), bleached kraft pulp of softwood (NBKP) and the like. Examples of the mechanical pulp include groundwood pulp (GP), refiner GP (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), and the like. Further, as the pulp, it is also possible to use deinked waste paper, corrugated waste paper, magazines, copy paper and the like. The pulp may be used alone or in combination of two or more.

  Wood pulp contains lignocellulose and is mainly composed of cellulose, hemicellulose, and lignin. In the present specification, a pulp in which lignin is not completely removed and a small amount of lignin is present in the pulp is referred to as lignopulp, and thus the pulp is obtained by the various pulping methods described above, and even a small amount is detected in the pulp. The thing containing the possible lignin is contained in ligno pulp.

  Lignopulp can be advantageously used in the present invention because of its large yield from raw materials, the small number of steps, and the small amount of processing chemicals. The amount of lignin contained can be quantified by the Klarson method.

  In the present invention, wood pulp is subjected to a treatment such as disintegration, beating, defibration using a refiner or a beater or a combination thereof in advance, and the Canadian Standard Freeness (CSF) value (freeness) after the treatment is Usually, 40 mL to 500 mL, preferably 40 mL to 300 mL, and more preferably 40 mL to 200 mL can be used.

  The microbial cellulosic fibers can be obtained, for example, from microbial pulp obtained by removing proteins and other contaminants from a mixture of cellulosic fibers and cells recovered from a culture solution in which acetic acid bacteria are cultured. ..

  In the cellulosic fibers derived from microorganisms, nano-level cellulosic fibers are usually entangled in a mesh, and this can be used as a raw material for a hydrophobic cellulosic fiber assembly.

  The defibrating material of the present case is characterized in that a part of the hydrogen atoms of the hydroxyl group of the cellulosic fiber is substituted with the acyl group (A) or the alkyl group (B) which may have a substituent. .. In the present specification, substituting the hydrogen atom of the hydroxyl group of the cellulosic fiber is called “chemical modification”, and the substituent introduced in place of the hydrogen atom of the hydroxyl group is sometimes called “chemical modifying group”.

  By selecting an acyl group (A) or an alkyl group (B) that may have a substituent as a substituent of a hydrogen atom of a part of the hydroxyl group of the defibrating raw material of the present case, chemical modification with such a substituent is performed. The defibration material thus obtained not only has improved thermal stability, but the defibration aid of the present invention facilitates microfibrillation during the defibration process, and is easily defibrated by the chemically modified MFC of the present case. ..

  This is because in the defibration raw material, hydrogen bonds between hydroxyl groups originally present on the surface of the cellulosic fiber have partially disappeared, so that there is also the effect of the defibration aid of the present invention during the defibration treatment. It is thought that this is because microfibrillation becomes easier.

  Since this chemically modified MFC is also made hydrophobic by being chemically modified with an acyl group (A) or an alkyl group (B) which may have a substituent, it is more hydrophobic than the original cellulosic fiber. Has a high affinity with the thermoplastic resin and is easily dispersed uniformly in the resin. Therefore, the molded article of the present invention made of the composition containing the chemically modified MFC of the present invention produced using the defibrating agent of the present invention and the thermoplastic fiber has excellent strength characteristics.

  The acyl group (A) (Ra-CO-) is preferable as the substituent in the defibrating raw material. Cellulose fibers chemically modified with an acyl group (A) and microfibrillated by defibrating the defibration material using the defibration aid of the present invention (this cellulose fiber is “Acyl(A)MFC” has a high affinity with the thermoplastic resin and can be uniformly dispersed in the thermoplastic resin.

  By selecting the acyl group (A) as a substituent in the defibrating material of the present case, the heat resistance of the defibrating material of the present case can be improved.

  Further, when preparing the defibrated raw material modified by an acyl group (A), not only the high crystallinity of cellulose in the pulp of the raw material can be maintained, but this high crystallinity is It can also be retained in Acyl(A) MFC produced by microfibrillating the defibrated material.

  In the acyl group (acyl group (A)) represented by the general formula (A): (Ra-CO-), Ra may have an alkyl group having 1 to 4 carbon atoms or an electron-donating substituent. Indicates a phenyl group.

  The alkyl group having 1 to 4 carbon atoms includes a linear alkyl group and a branched alkyl group. These straight-chain alkyl groups include methyl, ethyl, n-propyl, and n-butyl, and branched-chain alkyl groups include isopropyl and tert-butyl.

  As the acyl group (A) in which Ra is an alkyl group having 1 to 4 carbon atoms, an acyl group having 2 to 5 carbon atoms is preferable. Specific examples of such an acyl group include an acetyl group, an ethylcarbonyl group, an n-propylcarbonyl group and a pivaloyl group. These are preferable because the acylating agent used for acylation is available at a lower cost than other acylating agents. Among these, an acetyl group is more preferable.

  Examples of the phenyl group which may have an electron-donating substituent include phenyl, tolyl, ethylphenyl, methoxyphenyl, ethoxyphenyl and the like.

  Specific examples of the acyl group (A) that is a phenyl group in which Ra may have an electron-donating substituent include benzoyl, 4-methylbenzoyl, 4-ethylbenzoyl, 4-methoxybenzoyl, 4-ethoxybenzoyl, etc. Is mentioned. Among these aromatic acyl groups, a benzoyl group, a 4-methoxybenzoyl group, and a 4-methylbenzoyl group are preferable because modification with these gives a cellulosic fiber having particularly good thermal stability. A benzoyl group is more preferable because it is an acylating agent that can be obtained at a lower cost than an aromatic acylating agent and can be introduced into cellulosic fibers.

  As the substituent used in the defibrating raw material of the present case, an alkyl group (B) (Rb-) which may have a substituent can also be used. The defibration aid of the present invention is used to defibrate the present defibration material having an alkyl group (B) which may have a substituent, and the alkyl group (B) which may have a substituent. ) Modified and microfibrillated cellulosic fiber (this cellulosic fiber is referred to as “Alkyl(B)MFC”) has a high affinity with the thermoplastic resin and is uniformly dispersed in the thermoplastic resin. can do.

  Further, when preparing the present defibrating material modified with an alkyl group (B) which may have a substituent, not only the high crystallinity of cellulose in the pulp as the material can be maintained, but also this high The crystallinity can be retained even in Alkyl(B) MFC produced by microfibrillating the above defibrated raw material.

  In the alkyl group which may have a substituent and is represented by the general formula (B): Rb-, Rb is an alkyl group having 1 to 4 carbon atoms, a 2-hydroxyethyl group, a 2-hydroxypropyl group, 2- A cyanoethyl group or an allyl group is shown.

  Examples of the alkyl group having 1 to 4 carbon atoms include a linear alkyl group (methyl, ethyl, n-propyl, and n-butyl) and a branched alkyl group (isopropyl), with methyl and ethyl being preferred.

  As the alkyl group (B) which may have a substituent, a methyl group, an ethyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-cyanoethyl group and an allyl group are preferable.

  Alkyl (B) MFC, which is produced as a result of defibrating the defibration material chemically modified with these groups using the defibration aid of the present invention, has a high affinity with a thermoplastic resin, It can be uniformly dispersed in the thermoplastic resin.

  The degree of modification (substitution degree, also referred to as “DS”) with the acyl group (A) or the alkyl group (B) which may have a substituent in the defibrating raw material of the present invention is higher than that of the cellulose group constituting the cellulose fiber assembly. The hydrogen atom of the hydroxyl group present in one unit (repeating unit) of the molecule is represented by the degree to which the substituent is substituted.

  When the cellulose fiber aggregate is entirely composed of cellulose (in the case of cellulose), this repeating unit is a glucopyranose residue, and since the number of hydroxyl groups per unit is 3, the upper limit of the substitution degree is 3. Is.

  On the other hand, when the cellulosic polymer is lignocellulose, the lignocellulose contains hemicellulose and lignin together with cellulose. The number of hydroxyl groups of the xylose residue in xylan and the galactose residue of arabinogalactan contained in hemicellulose is 2, and the number of hydroxyl groups of the standard lignin residue is 2, and the number of these hydroxyl groups is 3 Smaller than

  Therefore, the upper limit of the degree of substitution in the lignocellulosic fiber aggregate (ligno pulp) is less than 3. The upper limit of this substitution degree is about 2.7 to 2.8 depending on the contents of hemicellulose and lignin contained in the lignocellulosic fiber (ligno pulp).

  As described above, although it depends on the content of hemicellulose or lignin in the cellulosic fiber aggregate, the chemically modified microfibrillated cellulose obtained by defibrating it in the defibrating raw material (chemically modified cellulosic fiber aggregate) of the present case as well. Also in the system fiber (the present chemically modified MFC), the degree of substitution (DS) by the acyl group (A) or the alkyl group (B) which may have a substituent is preferably about 0.1 to 1.5. The substitution degree (DS) is more preferably about 0.2 to 1.2, further preferably about 0.3 to 1.2. In particular, the substitution degree (DS) when the acyl group (A) is an acetyl group is more preferably about 0.4 to 1.2. A chemically modified MFC having a DS in the above range has an appropriate degree of crystallinity and SP (solubility parameter), and therefore is uniformly dispersed in a matrix (thermoplastic resin) and melted containing such a chemically modified MFC. The kneaded composition has excellent physical properties.

The degree of substitution (DS) can be analyzed by various analysis methods such as neutralization titration method, FTIR, two-dimensional NMR ( ¹ H and ¹³ C-NMR) and the like.

  In the present invention, the microfibrillated cellulosic fiber (MFC) does not mean a fiber in which the diameters of the respective fibers constituting the above-mentioned cellulosic fiber aggregate are all nano-ordered, and microfibrillated. It means a cellulosic fiber containing at least a portion, and the cellulosic fiber mentioned above has a nano-order diameter, or the fiber inside or on the surface of the fiber has a nano-order diameter.

  The fiber diameter of the chemically modified microfibrillated cellulosic fiber (chemically modified MFC) referred to in the present specification is about several tens nm to several μm.

  And, as described above, the meaning of the microfibrillated cellulosic fibers in the chemically modified MFC does not mean the fibers in which the diameters of the respective fibers are all nano-ordered, but at least the microfibrillated portion. The term “cellulosic fibers” is meant to include the above-mentioned cellulosic fibers having a nano-order diameter, or the fibers inside or on the surface of which have a nano-order diameter.

  The fiber diameter and fiber length of the MFC and the chemically modified MFC of the present case can be measured by taking a scanning electron microscope (SEM) photograph of 500 to 10000 times. The average value of the fiber diameter (average fiber diameter) and the average value of the fiber length (average fiber length) can be obtained as an average value when measured for at least 50 MFCs or chemically modified MFCs in the field of view of the SEM. ..

  The fiber diameter and fiber length of the present chemically modified MFC are also as described above.

  When the SEM photograph of the chemically modified MFC in the thermoplastic resin composite is taken, a solvent in which the thermoplastic resin is soluble and the chemically modified MFC is insoluble (for example, a polyamide composite and a polyester composite) is used. Hexafluoroisopropanol for the body, dichloromethane for the polycarbonate composite, non-polar high-boiling hydrocarbons such as decalin and xylene for the polyethylene composite and polypropylene composite) to elute the thermoplastic resin in the composite. Then, it is preferable to take a SEM photograph of the remaining chemically modified MFC of the present case.

4. Manufacturing Method of the Disentanglement Raw Material The manufacturing method of the disentanglement raw material (chemically modified cellulosic fiber aggregate) will be described below.

  The defibrating material of the present case may have a part of the hydroxyl groups of the cellulosic fiber acylated with the acyl group represented by the general formula (A) or may have a substituent represented by the general formula (B). It can be produced by etherification with an alkyl group.

  As a raw material for this acylation or etherification, a plant-derived cellulosic fiber aggregate (pulp) is used.

  Pulp is processed by disintegrating, beating, defibrating, etc., using a refiner or beater or a combination thereof in advance, and a Canadian Standard Freeness (CSF) value (freeness) after the treatment is 40 mL to 500 mL, Preferably 40 mL to 300 mL, more preferably 40 mL to 200 mL of pulp is used. By using the CSF pulp of this level, it becomes easy to form microfibrils in the defibration process.

  As a raw material for producing the present defibrating raw material, it is preferable to use a lignocellulosic fiber aggregate derived from wood, and in this case, it is more preferable to use lignopulp. Lignopulp is lower in cost than pulp containing no lignin, so that the defibrating material can produce a resin composite containing fibrillated fibers and a molded article of the present invention made of the same at low cost. it can. In order to obtain a melt-kneaded composition with little coloring, the lignin content of lignopulp is preferably 15% by mass or less, more preferably about 7% or less, further preferably about 5% or less. Is most preferred.

  Examples of the shape of the cellulosic fiber aggregate (pulp, sometimes referred to as raw material pulp hereinafter) used for the preparation of the defibrating raw material (chemically modified pulp) include cotton, paper, sheet, and non-woven fabric. Be done. When a paper-like, sheet-like, or non-woven fabric-like material is used, it is preferable that after chemical modification, it is made into a cotton-like or powder-like material by a means such as cutting or crushing, and is mixed with a resin in advance and subjected to the defibration treatment step.

  The preparation method (acylation reaction) of the defibrating raw material (acylated pulp) chemically modified with the acyl group (A) will be described.

  The acylation of the raw material pulp with the acyl group (A) is carried out by a known method, for example, by reacting the acylating agent having the acyl group (A) with the raw material pulp in a solvent with stirring or in a stationary state. Can be done by.

  Examples of the acylating agent having an acyl group (A) include carboxylic acid anhydrides, carboxylic acid halides such as carboxylic acid chlorides, and carboxylic acid vinyl esters. Among these, carboxylic acid vinyl ester) is preferable because it is easy to remove by-products from the reaction system.

  In the chemical modification with an acyl group (A), by using a corresponding carboxylic acid vinyl ester (vinyl carboxylate) as an acylating agent, the color of the chemically modified cellulosic fiber obtained by acylation is reduced, and as a result, It is possible to reduce the coloring of the melt-kneaded composition (composite) produced by compounding this.

  Of course, an acylating agent other than carboxylic acid vinyl ester (for example, carboxylic acid chloride, carboxylic acid anhydride) can also be used. In this case, it is preferable to add an organic base or an inorganic base in order to trap the acid (hydrochloric acid, carboxylic acid, etc.) by-produced in the acylation reaction during the reaction. However, the salt formed is likely to be mixed into the acylated cellulosic fiber, and the target acylated cellulosic fiber may be colored due to this. In this case, careful purification is required.

  Among these acylating agents, an acylating agent in which the acyl group (A) has an acyl group selected from the group consisting of an acetyl group, a pivaloyl group, a benzoyl group, a 4-methoxybenzoyl group and a 4-methylbenzoyl group, It is preferable to use it because an acylated microfibrillated cellulosic fiber having particularly good thermal stability can be produced.

  Specific examples of the acylating agent having an acyl group include vinyl acetate, acetic anhydride, vinyl pivalate, pivalic anhydride, vinyl benzoate, vinyl 4-methoxybenzoate, vinyl 4-methylbenzoate and the like.

  Among these, acylating agents having an acetyl group (vinyl acetate and acetic anhydride) are preferable from the viewpoint of production cost.

  The acylation reaction is preferably carried out in a solvent in the presence of a base.

  As the solvent, a solvent that does not react with the acylating agent, easily swells the acylating raw material, and can be easily removed from the reaction system after the reaction with the acylating raw material is preferable.

  Examples of such a solvent include polar aprotic solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc) and dioxane. The amount of the solvent used is about 20 to 200 parts by mass with respect to 1 part by mass of the acylated raw material in a dry state.

  However, when the acylating agent is liquid at the reaction temperature and the substance by-produced by the reaction is also liquid, the acylating agent and by-product can be used as a solvent. In this case, the amount of the solvent used is about 0 to 3 parts by mass with respect to 1 part by mass of the acylating raw material. For example, in the case of acylation (that is, acetylation) using acetic anhydride as an acylating agent, the amount of the solvent used is 0 (no solvent) to 3 parts by mass with respect to 1 part by mass of the acylating raw material. is there.

  Examples of the base include amines such as pyridine and dimethylaniline; alkali metal salts of acetic acid such as potassium acetate and sodium acetate; carbonates of alkali metals such as lithium carbonate, potassium carbonate and sodium carbonate. The amount of the base used is about 0.1 to 1 mol with respect to 1 mol of the hydroxyl group in the acylating raw material.

  The amount of the acylating agent used with respect to the raw material pulp can be appropriately adjusted depending on the water content of the raw material pulp, the desired degree of acylation (degree of substitution, DS) and the like.

  For the degree of acylation (degree of substitution, DS) during the acylation reaction, collect an amount required for analysis from the reaction mixture, and then wash, extract, etc. unreacted acylating agent and acylating by-products. After the removal, the FTIR spectrum can be measured and quantified using a calibration curve prepared in advance. Therefore, the reaction is stopped when the target DS is reached, and the reaction mixture is subjected to ordinary purification operations such as filtration, washing, and extraction to obtain an acylated cellulose fiber assembly having the target DS. (Acylated pulp) can be obtained.

  The amount of the acylating agent used is about 0.5 to 2 times the molar number of hydroxyl groups present in the raw pulp. When the raw material pulp is in a water-containing state, it is preferable to use an acylating agent larger than the above in consideration of the amount of the acylating agent consumed by this water.

  The description of the DS of acylation and the preferable DS value are as described in the above section “3.

  The reaction temperature is usually about 10 to 120°C, preferably about 20 to 100°C.

  The reaction time is usually about 2 to 24 hours when the wood-derived material pulp is acylated, and is usually about 4 to 100 hours when the fine material-derived material pulp is acylated.

  The preparation method (etherification reaction) of the defibrating material (etherified pulp) chemically modified with an alkyl group (B) which may have a substituent will be described.

  Etherification is a reaction for forming an ether bond between oxygen atoms of some hydroxyl groups in the pulp and an alkyl group (B) which may have a substituent. The reaction that forms this ether bond is called the etherification reaction, and the agent used for the etherification is called the etherification agent.

  The etherification reaction is usually carried out by reacting the etherifying agent and the etherification raw material in a suspension state while stirring in a solvent.

  As the etherified raw material, the same material as the acylated raw material (raw pulp) can be used.

  The etherification reaction is preferably carried out in a solvent in the presence of a base. The etherifying agent used is as follows.

  When Rb- in the general formula (B) is an alkyl group having 1 to 4 carbon atoms or an allyl group, a corresponding halide (for example, halogenated (alkyl having 1 to 4 carbon)) or halogen is used as an etherifying agent. Allyl chloride) can be used.

  When Rb- is a 2-hydroxyethyl group or a 2-hydroxypropyl group, an epoxide (ethylene oxide or propylene oxide) corresponding to these groups can be used as an etherifying agent.

  When Rb- is a 2-cyanoethyl group, acrylonitrile is used as the etherifying agent.

  Of these etherifications, the alkyl group (B) which may have a substituent is selected from the group consisting of a methyl group, an ethyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, an allyl group and a 2-cyanoethyl group. It is preferable to carry out etherification so that at least one kind selected is used, because etherified cellulose fibers having good thermal stability can be produced at low cost.

  The solvent is preferably a solvent which is non-reactive with the raw material pulp, easily swells the raw material pulp, and is easily removed from the reaction system after the reaction with the raw material pulp. As such a solvent, the same solvent as in the case of the above acylation can be mentioned. The amount of solvent used is the same as in the case of the above acylation.

  Examples of the base include alkali metal hydroxides such as sodium hydroxide and lithium hydroxide. The amount of the base used is about 1 to 2 equivalents with respect to the etherifying agent.

  The reaction temperature is usually about 0 to 100°C, preferably about 10 to 90°C.

  The reaction time varies depending on the amount of the etherifying agent and the base used, but is usually 0.5 to 10 hours.

  The amount of the etherifying agent used with respect to the raw material pulp can be appropriately adjusted depending on the water content of the raw material pulp and the intended degree of etherification (degree of substitution, DS) with respect to the raw material pulp.

  The degree of etherification (degree of substitution, DS) can be followed by taking an amount required for analysis from the reaction mixture and purifying the reaction mixture from this, for example by measuring the NMR spectrum.

  The preferred DS value for etherification is as described above.

5. Method of defibrating the defibrating material and method of producing a composition containing defibrated chemically modified nanofibrillated cellulosic fibers The defibration of the defibrating material is based on the defibration aid of the present invention. In addition to the defibration medium (water or a mixed solvent of water and an organic solvent soluble in water, or an organic solvent in which the chemically modified cellulose fiber and the thermoplastic resin to be composited are insoluble) together with the agent, This can be carried out by performing a defibrating process such as stirring and kneading in a state where the defibrating material is dispersed.

  When a composite containing a resin and a chemically modified cellulosic fiber is produced by a melt kneading method, it is efficient to carry out the defibration treatment using a uniaxial or multiaxial kneader.

  Further, the defibrating material can be defibrated in the melted thermoplastic resin at the stage of performing the melt-kneading operation on the mixture of the defibrating material, the defibration aid and the thermoplastic resin to be composited. . It is preferable to use a uniaxial or multiaxial kneader for this melt kneading.

  The defibration aid used may be contained in the resin composition or may be removed from the resin composition. It is preferable to remove the defibration aid from the resin composition from the viewpoint of the strength characteristics of the formed body. However, it is not necessary to completely remove the defibration aid, and removal may be performed to such an extent that the physical properties of the obtained resin composition are not affected. Even if the defibration aid remaining in the resin composition is in a very small amount, by analyzing and detecting it, it is possible to know that the resin composition was produced by the production method of the present invention. Useful for product tracking.

  When a defibration aid that is solid at room temperature (for example, ε-caprolactam) is used as the defibration aid, it cannot be unequivocally determined depending on the resin used, but is 0.1 to 5 relative to the total amount of the resin composition. It may be preferable to leave the defibration auxiliary agent in an amount of about% by mass. This is because a molded product containing a small amount of the defibration aid which is solid at room temperature may show superior strength characteristics, depending on the resin used, as compared with a molded product containing no defibration aid at all. is there.

  Examples of the production method of the present invention relating to the resin composition containing the chemically modified microfibrillated cellulosic fiber (chemically modified MFC) include the following Method I to Method III.

  Method I is a method for producing a resin composition containing a chemically modified MFC by defibrating a chemically modified cellulosic fiber aggregate (the above-mentioned defibrating raw material of the present case) and complexing it with a resin.

In detail,
(1) The above-mentioned defibration aid of the present invention is used to defibrate the above-mentioned hydrophobized cellulosic fiber aggregate (this defibration material), and microfibrillated hydrophobized cellulosic fibers (chemical modification) Chemically modified MFC, which includes a first step of producing microfibrillated cellulosic fibers or chemically modified MFC), and (2) a second step of mixing the chemically modified MFC obtained in the first step with a resin A method for producing a resin composition containing a resin and a resin.

  In the method II, a mixture containing three kinds of the defibration aid of the present invention, the chemically modified cellulosic fiber aggregate (the above-mentioned defibrating raw material) and the resin is prepared, compounded, and the chemically modified MFC is contained. It is a method for producing a resin composition.

  Specifically, the defibration aid of the present invention, the hydrophobized cellulosic fiber aggregate (the defibrating material of the present case), and the resin are mixed, and the hydrophobized cellulosic fiber is mixed during the mixing operation. Production of a resin composition containing a microfibrillated hydrophobized cellulosic fiber (chemically modified MFC) and a resin, which comprises a step of defibrating an aggregate (the above-mentioned defibrating raw material) to microfibril Is the way.

  In the method III, the defibration aid of the present invention, the chemically modified cellulosic fiber aggregate (the above-mentioned defibration raw material) and the resin are mixed and combined, and then the defibration aid of the present invention is removed. A method for producing a resin composition containing a chemically modified MFC.

In detail,
(1) A defibration aid of the present invention, a hydrophobized cellulose-based fiber assembly (the above-mentioned defibration raw material) and a resin are mixed, and this hydrophobized cellulose-based fiber assembly (the above-mentioned defibration raw material) is unwound. Of the first step of fiberizing and microfibrillating, and (2) the defibration aid of the present invention obtained in the first step, microfibrillated hydrophobized cellulosic fibers (chemically modified MFC), and resin A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber (chemically modified MFC) and a resin, comprising a second step of removing a defibration aid from a mixture.

  In the step of mixing the resin with the microfibrillated hydrophobized cellulosic fiber or the hydrophobized cellulosic fiber aggregate according to any one of the above Method I to Method III, a compatibilizer may be further mixed. preferable.

  By mixing the compatibilizing agent, the mixed state with the chemically modified MFC and the thermoplastic resin, particularly the thermoplastic resin having a high hydrophobicity (for example, polypropylene, polyethylene, etc.) is improved, and thus the present invention containing these thermoplastic resins is improved. The strength characteristics of the molded article are improved.

  As the compatibilizer, it is preferable to use a polymer compound having a hydrophobic polymer and a hydrophilic group or a hydrophilic fragment. Specific examples of such a polymer compound include maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene, or a block polymer composed of a hydrophobic fragment and a hydrophilic fragment.

  It is preferable to use those having a solubility parameter (SP value) of about 12 to 15, and preferably about 12.5-14.5 for both the defibrating raw material and the chemically modified MFC.

  In each of the above production methods, the thermoplastic resin used is preferably one or more thermoplastic resins. In particular, when a composite containing a highly hydrophobic thermoplastic resin (for example, polypropylene, polyethylene, etc.) is produced, the SP value of the highly hydrophobic thermoplastic resin is larger than that of the chemically modified cellulosic fiber used. It is preferable to use a thermoplastic resin (for example, polylactic acid, polyamide 6 or the like) having an SP value smaller than the SP value of 1 in combination with a highly hydrophobic thermoplastic resin resin (for example, polypropylene, polyethylene or the like).

  Specifically, for example, polypropylene (this SP value is 8.1) as a thermoplastic resin and chemically modified microfibrillated cellulosic fiber having an SP value of about 14 (for example, microfibrillated acetyl ligno with an SP value of about 14). In the case of producing a composite containing (cellulosic fibers), it is possible to use, for example, polylactic acid (this SP value is 11.4) and/or polyamide 6 (this SP value is 12.2) together with polypropylene. preferable.

  As the resin used in the method for producing the composition containing the fiber and the resin of the present invention, a thermoplastic resin among various resins is preferably used because of its excellent productivity and versatility.

  In each of the above production methods, as the thermoplastic resin preferably used, polyamide, polyolefin, aliphatic polyester, aromatic polyester, polyacetal, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate-ABS alloy (PC-ABS alloy) and modified polyphenylene ether (m-PPE).

  As the thermoplastic resin, the above resins may be used alone or as a mixed resin of two or more kinds.

  As polyamide (PA), polyamide 6 (nylon 6, PA6), polyamide 66 (nylon 66, PA66), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 11 (PA11), polyamide 12 (PA12), polyamide 46 Polyamide XD10 (PAXD10), polyamide MXD6 (PAMXD6) and the like can be preferably used.

  As the polyolefin, polypropylene (PP), polyethylene (PE, especially high-density polyethylene HDPE), a copolymer of ethylene and propylene, maleic anhydride-modified polypropylene (MAPP) and the like can be preferably used.

  Further, polyisobutylene (hereinafter also referred to as “PIB”), polyisoprene (hereinafter also referred to as “IR”), polybutadiene (hereinafter also referred to as “BR”) and the like can be preferably used.

  As the polypropylene (PP), isotactic polypropylene (iPP), syndiotactic polypropylene (sPP) and the like can be preferably used.

  As an aliphatic polyester, a polymer or copolymer of a diol and an aliphatic dicarboxylic acid such as succinic acid or valeric acid (for example, polybutylene succinate (PBS)), or a hydroxycarboxylic acid such as glycolic acid or lactic acid alone. Polymers or copolymers (for example, polylactic acid, poly ε-caprolactone (PCL), etc.), and copolymers of diols, aliphatic dicarboxylic acids and the above hydroxycarboxylic acids and the like can be preferably used.

  As the aromatic polyester, a polymer of a diol such as ethylene glycol, propylene glycol or 1,4-butanediol and an aromatic dicarboxylic acid such as terephthalic acid can be preferably used. Specifically, for example, polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT) and the like can be preferably used.

  As the polyacetal (also referred to as polyoxymethylene, POM), in addition to a homopolymer of paraformaldehyde, a copolymer of paraformaldehyde and oxyethylene can be preferably used.

  For polycarbonate (PC), a reaction product of bisphenol A or a bisphenol derivative thereof and phosgene or phenyldicarbonate can be preferably used.

  As polystyrene (PS), in addition to general-purpose PS (GPPS), PS (HIPS) in which a rubber component is dispersed in a PS matrix to improve impact resistance can be suitably used. In addition to polystyrene (PS), styrene copolymers (acrylonitrile-butadiene-styrene copolymer, ABS resin) are preferred resins as the matrix of the fiber-reinforced resin composition of the present invention.

  A blended product of polycarbonate (PC) and ABS (PC-ABS alloy) is excellent in impact resistance, weather resistance and molding processability, and therefore is used as a matrix of the resin composition in each of the above production methods of the present invention. Preferably.

  The blended product of PPE and PS (PPE-PS blended product) is a type of modified polyphenylene ether (PPE) (m-PPE). The PPE-PS blend product is preferably used because it has high heat resistance and is lightweight.

  Further, as the thermoplastic resin other than the above, for example, polyvinyl chloride, polyvinylidene chloride, fluororesin, (meth)acrylic resin, (thermoplastic) polyurethane, vinyl ether resin, polysulfone resin, cellulose resin (for example, (Acetylated cellulose, diacetylated cellulose, acetylbutyl cellulose, etc.) and the like can be used.

  The composite of the thermoplastic resin and the chemically modified microfibrillated cellulosic fiber is preferably performed by a melt kneading method.

  In the kneading step, the defibrating material is chemically modified in the melted thermoplastic resin while the defibrating material (also referred to as a chemically modified cellulosic fiber aggregate or chemically modified pulp) and the thermoplastic resin are melt-kneaded. It is a step of defibrating the microfibrillated cellulosic fibers (chemically modified MFC) to produce a composition containing the chemically modified MFC and the thermoplastic resin.

  When the melt-kneaded composition contains additives other than the defibration aid, the defibration material and the thermoplastic resin are melt-kneaded together by adding them in the mixing step of the raw materials to be melt-kneaded or in this melt-kneading step Preferably.

  The melt-kneading composition can be produced by melt-kneading the thermoplastic resin, the defibrating material of the present invention, the defibration aid of the present invention, and optionally an additive.

  The heating temperature can be adjusted according to the melting point of the thermoplastic resin used. As the heating temperature, the minimum processing temperature ±10° C. recommended by the thermoplastic resin supplier is preferable. By setting the heating temperature in this temperature range, the chemically modified MFC and the thermoplastic resin can be uniformly mixed.

  The melt-kneading time may be adjusted in consideration of the production amount and the operating conditions such as the performance of the device and the rotation speed within the range recommended by the kneader manufacturer. A shorter heating time is preferable because deterioration of the melt-kneaded product due to heat and oxidation can be prevented. Further, in order to prevent deterioration due to heating and oxidation during melt-kneading, it is preferable to add an additive such as an antioxidant and knead in a nitrogen atmosphere.

  A uniaxial or multiaxial kneader can be preferably used as the kneader. It is preferable to increase the number of rotations of the uniaxial or multiaxial kneading machine used because the chemically modified pulp is easily microfibrillated during the melt kneading step.

  In this melt-kneading step, the chemically modified pulp is defibrated by the action of shearing stress and a defibration aid during kneading, microfibrillated, and the chemically modified fibrillated cellulosic fibers produced are suppressed from agglomerating with each other. It is well dispersed in the thermoplastic resin.

  In this kneading step, the chemically modified pulp having a fiber diameter of several tens μm to several hundreds μm is defibrated into the chemically modified microfibrillated cellulosic fibers having a fiber diameter of several tens nm to several μm during the kneading.

  The defibrating material of the present case can be compounded with the thermoplastic resin while defibrating by the action of the shear stress of the melt-kneading machine and the defibration aid during the melt-kneading with the thermoplastic resin. Therefore, according to the melt-kneading method, the manufacturing process is simple and the manufacturing cost can be reduced.

  Note that it is also possible to mix both the chemically modified cellulose fiber aggregate (also referred to as the chemically modified pulp or the defibrating raw material of this case) and the thermoplastic resin in advance prior to melt-kneading. For example, (i) the dry chemically modified MFC or chemically modified pulp may be mixed with a powdery or granular thermoplastic resin, and the obtained mixture may be supplied to a kneader. Alternatively, (ii) the chemically modified pulp and the powdery or granular thermoplastic resin may be respectively dispersed in a dispersion liquid in which they are not dissolved, mixed, and dried, and then supplied to the kneader. As a mixing means, it is preferable to use a bench roll, a Banbury mixer, a kneader, a planetary mixer, a Henschel type mixer, a stirrer with stirring blades, or an orbital or autorotating stirrer. When the chemically modified pulp and the powdery or granular thermoplastic resin are respectively dispersed in a dispersion liquid in which these are not dissolved and then mixed, it is preferable to use a wet media type attritor or a wet pulverizer trigonal. The reason is that the defibration and dispersion of the chemically modified pulp and the mixing of the chemically modified pulp and the thermoplastic resin can be performed at the same time.

  When the dry chemically modified pulp and the powdery or granular thermoplastic resin are mixed in advance before the melt-kneading as in the above (i), an additive can be added during the mixing. Is.

  The content ratio of the chemically modified microfibrillated cellulosic fiber (chemically modified MFC) in the melt-kneaded composition produced by the production method of the present invention is usually 1 to 40 mass with respect to the total mass of the resin and the chemically modified MFC. %, and preferably 3 to 30 mass %. By setting the content of the chemically modified micro MFC in the above range, a melt-kneaded composition having excellent strength characteristics can be obtained.

  The melt-kneaded composition produced by the production method of the present invention can also be used as a masterbatch. When used as a masterbatch, the content ratio of the chemically modified MFC is preferably about 10 to 40% by mass based on the total mass of the thermoplastic resin and the chemically modified MFC.

  The composition produced by the production method of the present invention is a composition in which a thermoplastic resin and a chemically modified MFC are melt-kneaded. Since the melt-kneading method has higher productivity than the method of manufacturing the composite by impregnating the nonwoven fabric with the resin or the resin precursor solution and the cellulosic fiber, the chemically modified MFC can be produced with high productivity by the manufacturing method of the present invention. The resin composition containing it can be manufactured.

  The melt-kneaded composition of the present invention can contain additives within a range that does not impair the effects of the present invention. As additives, for example, compatibilizers, surfactants, starches, polysaccharides such as alginic acid, natural proteins such as gelatin, glue, casein, etc., inorganic compounds such as tannin, zeolite, ceramics, metal powders, colorants, plasticizers. Agents, pigments, antistatic agents, ultraviolet absorbers, antioxidants and the like.

6. Molded Product A molded product of the present invention can be manufactured using the melt-kneaded composition manufactured by the manufacturing method of the present invention. When producing a molded product, the melt-kneaded composition may be processed into various shapes such as pellets, powders, sheets, plates and films, and used as a molding material.

  Examples of the molding method include injection molding, mold molding, extrusion molding and the like. Examples of the shape of the molded body include a sheet shape, a plate shape, a film shape, and a three-dimensional structure. Molded articles having various shapes can be manufactured according to the above-mentioned molding methods.

  By using the melt-kneaded composition produced by the production method of the present invention, a molded article having excellent strength properties and the like can be obtained.

  The molded article produced from the melt-kneaded composition produced by the production method of the present invention can be used in fields requiring mechanical strength (tensile strength, etc.).

  Specifically, for example, interior materials, exterior materials, structural materials, etc. of transportation equipment such as automobiles, trains, ships, airplanes; housings, structural materials, internal parts, etc. of electric appliances such as personal computers, televisions, telephones, watches, etc. Housings, structural materials, internal parts, etc. for mobile communication devices such as mobile phones; Housings, structural materials, internal parts, etc. for portable music playback equipment, video playback equipment, printing equipment, copying equipment, sports equipment; building materials; It can be effectively used as office equipment such as stationery, containers, and containers.

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

The abbreviations used in the examples, comparative examples, and test examples have the following meanings.
Ac: Acetyl group NBKP: Softwood bleached kraft pulp NUKP: Softwood unbleached kraft pulp TUKP: Unbleached kraft pulp derived from Todomatsu AcNBKP: NBKP in which some of the hydrogen atoms of the hydroxyl groups in NBKP are replaced with acetyl groups
AcNUKP: NUKP in which hydrogen atoms of some hydroxyl groups in NUKP are substituted with acetyl groups
AcTUKP: TUKP in which hydrogen atoms of some hydroxyl groups in TUKP are substituted with acetyl groups
DMF:N,N-Dimethylformamide NMP:N-Methylpyrrolidone AcMFNBKP:NBKP: Some hydrogen atoms of the hydroxyl groups are replaced with acetyl groups, and microfibrillated fibers AcMFNUUKP:Part of the hydroxyl groups in NUKP Of the microfibrillated fiber in which the hydrogen atoms of the above have been replaced with acetyl groups, and some of the hydrogen atoms of the hydroxyl groups in TUKP have been replaced with acetyl groups, and the microfibrillated fibers AO: antioxidant

Further, the following terms used in Examples, Comparative Examples, Figures, and Tables have the following meanings.
-Pass: The number of times that the material to be kneaded (test material) is supplied to the biaxial kneader and is applied to the kneader is called "pass". Thus, for example, "1 pass" means that the kneader was run once, "1st pass" means that the test material was kneaded first (as the 1st time), and "2nd pass". Means that the material that has been kneaded once is then kneaded a second time.
-Extrusion: It means that an object to be treated (test material) is supplied to a kneader (also referred to as an extruder) and kneading is performed.
-Cold: Means processing at a temperature of 0 to about 30°C.

(A) Raw materials used In the following examples and comparative examples, the following raw materials were used.
(1) Resin/Polypropylene (hereinafter referred to as “PP”): Made by Japan Polypro, Novatec MA04A, MI=40, Pellet/Polypropylene powder (hereinafter referred to as “PP powder”): Made by Japan Polypro, Novatec MA04A, MI=40 , Powdery/polylactic acid pulverized product (hereinafter referred to as "PLA powder"): Nature Works, ingeo i3251D: MI=80, pulverized product/polyamide 6 pulverized product (hereinafter referred to as "PA6 powder"): Unitika, A1020 LP , Molar mass 12000g/mol, crushed product, polyamide 6 pellets (hereinafter referred to as "PA6 pellets"): Unitika, A1020BRL
・Polyacetal powder (hereinafter referred to as “POM powder”): Mitsubishi Engineering Rings, Iupital F30, MI=27
・High-density polyethylene pellets (hereinafter referred to as “HDPE pellets”): Asahi Kasei, Suntech J320, MI=12
In the present specification, high density polyethylene (HDPE) may be simply referred to as PE.
(2) Compatibilizer/maleic acid-modified polypropylene (hereinafter referred to as "MAPP"): Toyobo, Toyo Tuck H1000P, MI=110, powder
(3) Disentanglement auxiliary agent/clay: Shiraishi calcium, ORBEN-M, organically treated for polyamide, general-purpose talc: Nippon Talc, Microace MSZ-C, average particle size 12.8 μm, amino-based surface treated
(4) Additives/antioxidants (hereinafter referred to as "AO"): BASF, Irganox 1010, phenolic antioxidants

(B) Equipment used : Biaxial kneader: Technobel, screw diameter φ15 mm, L/D (ratio of screw length (L) and screw diameter (D)) 45
・Injection molding machine: NPS 7 type, mold clamping force 7 tons

(C) Test method and equipment used
(1) Microscopic observation of cellulosic fibers (hereinafter, simply referred to as “fibers”) The state of fibers, or the defibration or dispersion state of fibers in the composition was observed with the following polarization microscope and electron microscope.

(1-1) Observation of the defibrated state of the fibers in the fiber-containing composition by a scanning electron microscope
(a) Preparation of observation sample
a-1) Sample of fiber-containing composition (fiber, PP, MAPP, and PLA-containing composition) Using a mixed solvent in which xylene and tetrachloroethane were mixed at a ratio of 1/1, the fiber-containing composition was used to remove the resin component (PP , MAPP and PLA) were extracted and removed to prepare a sample. Specifically, the fiber-containing composition (PP/MAPP/PLA/AO/cellulose composite) is put into the above mixed solvent and heated at 140° C. for about 2 hours to extract and remove the resin component to remove the fiber. An extraction residue containing the main component was obtained. This was washed with ethanol, the obtained fiber was placed on a copper plate, dried, and then platinum-coated using a sputtering device (JEOL SEC-3000FC Auto Fine Coater), which was used as an observation sample.

a-2) Sample of fiber-containing composition (fiber, PP, MAPP and PA6-containing composition)
A resin component (PP, MAPP and PA6) was extracted and removed from the fiber-containing composition by sequentially using N-methylpyrrolidone (NMP) and xylene to prepare a sample. Specifically, first, a cellulose composite containing fibers, PP, MAPP, PA6 and AO was put into NMP and heated at 190° C. for about 2 hours to extract and remove PA6. Next, the composition from which PA6 was removed was added to xylene, heated at 140° C. for about 2 hours, and PP was extracted and removed to obtain an extraction residue containing fiber as a main component. This was washed with ethanol, the obtained fiber was platinum-coated in the same manner as above, and this was used as an observation sample.

The fiber-containing composition (fiber- and PA6-containing composition, or fiber- and POM-containing composition) was treated in the same manner as in the above a-2) to prepare an observation sample.
The fiber-containing composition (fiber, PE, MAPP and PLA-containing composition) was treated in the same manner as in the above a-1) to prepare an observation sample.

  (b) Observation equipment and observation method: Secondary electron image observation was performed on the obtained sample using a field emission scanning electron microscope (JSM-7800F: JEOL Ltd.).

(1-2) Observation of the disentangled state and dispersed state of the fibers in the fiber-containing composition by a polarization microscope
(a) Preparation of observation sample
(i) About 2 mm square test pieces were cut out from the fiber-containing composition.
(ii) A test piece was placed on a slide glass and a cover glass was placed on it.
(iii) The test piece was thinned by pressing with a press machine heated to 220 to 250°C.
(iv) The sliced sample was immersed in ice water and rapidly cooled to obtain an observation sample.

(b) Observation The obtained observation sample was observed with an observation device (system polarization microscope OLYMPUS BX51) at a crossed Nicol temperature of 23° C. and relative humidity of 50%.

(2) Strength test (3-point bending test)
-Method for manufacturing test piece (molded body) A strip-shaped test piece (10 x 80 x 4 mm) was produced using an injection molding machine (manufactured by Nissei Plastic Co., Ltd., NPX 7 type, clamping force 7 tons). The cylinder temperature of the injection molding machine was set to 170° C. (supply unit) to 190° C. (measurement unit) to melt the resin composition and inject it into a mold at a temperature of 35° C. to prepare a molded body. The obtained test piece was allowed to stand for 2 days in an atmosphere having a temperature of 23° C. and a relative humidity of 50%, and then tested.

-Test method A strength test was performed on the test piece using a universal tester (AG5000E manufactured by Shimadzu Corporation). The test conditions were a distance between fulcrums of 64 mm and a test speed of 10 mm/min.

<Production Example 1> Production of AcNUKP (lot number (1)EY262) DS=0.89
-Used pulp: Unbleached softwood kraft pulp (NUKP)
NUKP manufactured by Nippon Paper Industries Co., Ltd. was treated with a refiner to have a freeness (CSF) of 105 ml. This refined NUKP was paper-made to prepare a sheet-like NUKP (thickness: about 0.2 mm). Components of NUKP (% by mass): cellulose (78.3%), hemicellulose (11.3%), lignin (10.4%).
-Method for producing AcNUKP: 15.3 g of potassium acetate and 2846 ml of acetic anhydride were added to the above NUKP (1620 g as solid content, water content 15.07% by mass) and reacted at 100°C for 6 hours. The reaction mixture was cooled to 50° C., the liquid was removed by decantation, and acetic anhydride and acetic acid were distilled off at 60° C. under reduced pressure. It was dried under reduced pressure at 50°C for 26 hours to obtain AcNUKP having a dry weight of 1990 g. The DS of this AcNUKP was 0.89.

  An electron microscopic observation image of the obtained AcNUKP is shown in FIG.

  After cutting this into a sheet of 7 cm×7 cm, it was pulverized with a Henschel mixer and used for the production of the composites of the following Examples and Comparative Examples.

<Production Example 2> Production of AcTUKP (Lot number (16)NT-353)
・Pulp used: Unbleached kraft pulp derived from Todomatsu (TUKP)
TUKP manufactured by Nippon Paper Industries Co., Ltd. was subjected to a refiner treatment to give TUKP having a freeness (CSF) of 255 ml, and this was paper-made to obtain a sheet-like TUKP having a thickness of about 0.2 mm. TUKP component (mass %): cellulose (84.3%), hemicellulose (13.7%), lignin (2%). Solid content 74 mass %.
-Method for producing AcTUKP: 5600 g of acetic anhydride was added to the above-mentioned sheet-like TUKP (solid content 2400 g), and the mixture was reacted at 120°C for 5 hours. The reaction mixture was cooled to 50° C., the liquid was removed by decantation, and the mixture was heated to 60° C. under reduced pressure to distill off acetic anhydride and acetic acid. After drying, a sheet-like AcTUKP having a dry weight of 2200 g was obtained. The DS of this AcTUKP was 0.59. This AcTUKP was used for the defibration test described below.

  Hereinafter, acetylated pulps shown in the following table were produced in the same manner as above.

注１：化学修飾パルプを構成するそれぞれの官能基の質量比を、各官能基の質量部で示したものである。Acはアセチル基の質量部、Ligはリグニン残基の質量部を示す。「Cell＋Hem」は、化学修飾パルプを構成するセルロースのグルカン残基の質量部とヘミセルロースを構成する糖類（マンナン、キシラン等）の残基の質量部との合計質量部を示す。

Note 1: The mass ratio of each functional group constituting the chemically modified pulp is shown by the mass part of each functional group. Ac represents the mass part of the acetyl group, and Lig represents the mass part of the lignin residue. “Cell+Hem” represents the total mass part of the mass parts of the glucan residues of the cellulose that constitutes the chemically modified pulp and the mass parts of the residues of the saccharides (mannan, xylan, etc.) that constitute the hemicellulose.

(Example 1) Test number PP754
FIG. 2 is a schematic diagram illustrating the manufacturing method of Example 1. In addition, in FIG. 2, lactam indicates ε-caprolactam.

  First, a mixture of AcNUKP (Lot No. (3)T008), ε-caprolactam (defibration aid) and water is kneaded in a twin-screw kneader to perform AcNUKP defibration treatment, and then (in the second pass) under heating. The water was discharged to. Next, (in the third pass) PLA powder was added and melt-kneaded, and simultaneously ε-caprolactam was discharged together with the remaining water. Then, PP and MAPP were added to the obtained kneaded product and melt-kneaded to obtain a composition containing microfibrillated AcNUKP, PLA and PP, and ε-caprolactam remaining in the composition was discharged.

Hereinafter, each step shown in FIG. 2 will be described in detail.
(First pass: cold extrusion)
Cold extruding a mixture with a composition ratio of AcNUKP (Lot No. (3)T008)/ε-caprolactam/water/AO=(2.27+10)/30/40/1 using a twin-screw kneader with a water-cooled cylinder. I went.

In addition, the numerical value in the notation (AcNUKP/ε caprolactam/water/AO=(2.27+10)/30/40/1) of the composition ratio of the above mixture subjected to the biaxial kneader has the following meanings.
(2.27+10): It represents the mass ratio of AcNUKP in the total mass of the mixture.
Here, 2.27 in the above (2.27+10) means the mass ratio of the acetyl group (Ac) of AcNUKP in the total mass of the mixture (this is calculated from the DS value of AcNUKP). Further, 10 in the above (2.27+10) means the mass ratio of the fiber component (that is, cellulose+hemicellulose) in the total mass of the mixture. Therefore, 2.27+10=12.27 is the mass ratio of AcNUKP in the total mass of the mixture.
30: Mass ratio of ε-caprolactam in the total mass of the mixture
40: Mass ratio of water in the total mass of the mixture 1: Mass ratio of AO in the total mass of the mixture

  Unless otherwise specified, the description of the composition ratio of the mixture and the kneaded product follows this notation.

  The above description method of the numerical value of each component ratio in the mixture is applied to the notation of the ratio of each component in the resin composition.

  However, regarding the components (composition ratio) of the molded body (test piece) described in the table showing the strength test results in the present specification, the composition ratio of each component to the total mass of the molded body excluding the antioxidant is (Mass ratio).

  And the indication of the chemically modified fiber contained is described by its abbreviation (for example, acetylated softwood unbleached kraft pulp is described by its abbreviation AcNUKP), but the content mass is converted to unmodified fiber. (That is, the content mass of AcNUKP is converted to NUKP).

(2nd pass: dehydration extrusion)
The extruder cylinder was inclinedly heated to 70° C. (feeding part, sometimes referred to as “upstream part” in this specification) to 130° C. (metering part, sometimes referred to as “downstream part” in this specification), and vented. Dehydration extrusion was carried out by passing the mixture passed through 1 through the provided twin-screw kneader. The composition of the mixture after the second pass extrusion was AcNUKP/(ε caprolactam+water)/AO=(2.27+10)/33.52/1 (total total mass part: 46.79).

(3rd pass: melt kneading with PLA)
PLA powder was added to the mixture passed through 2 passes to prepare a PLA/2 pass mixture = 20/46.79 mixture, which was melt-kneaded with PLA using a twin-screw kneader at a cylinder temperature (160°C) at which PLA melts. .. The composition after extrusion was PLA/AcNUKP/(ε caprolactam+water)/AO=20/(2.27+10)/14.32/1 (total total mass part: 47.59).

(4th pass: Dilution extrusion with PP and MAPP)
Cylinder temperature (180-190℃) where all mixed resins melt by preparing PP/MAPP/3 pass mixture = 57.73/10/47.59 composition ratio by adding PP and MAPP to the mixture which passed 3 passes. Melt kneading was carried out using a biaxial kneader. Then, in order to remove the remaining water and ε-caprolactam, deaeration was performed by a vacuum vent. The composition ratio of the obtained composition was PP/MAPP/PLA/AcNUKP/AO=57.73/10/20/(2.27+10)/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG.

  According to the polarization microscope observation image of FIG. 3, the fiber diameter of the thick fiber was about 25 μm, and according to the electron microscope observation image, the fiber diameter of the thin fiber was about several tens nm to 2 μm. And it was observed that the number of disentangled fibers increased.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 2.

  In the present specification, the composition ratio of the components contained in the test piece (molded product) described in the table showing the results of the strength test is the composition ratio of each component to the total mass of the molded product excluding the antioxidant ( Mass ratio).

  And, the indication of the chemically modified fiber contained is described by its abbreviation (for example, acetylated softwood unbleached kraft pulp is described by its abbreviation AcNUKP), but the content mass is converted to unmodified fiber. (That is, the content mass of AcNUKP is converted to NUKP).

(Example 2) Test number PP717
A schematic diagram for explaining the manufacturing method of the second embodiment is shown in FIG.

  The method of Example 2 is the same as that of Example 1 except that three components of PP, MAPP and clay (defibration auxiliary agent) are added at once instead of adding PP and MAPP in the third pass. ..

Hereinafter, each step shown in FIG. 4 will be described in detail.
(First pass: cold extrusion)
A mixture with a composition ratio of AcNUKP (lot number (4)T001)/ε-caprolactam/water/AO=(3.96+10)/30/40/1 was cold extruded using a twin-screw kneader with water cooled cylinder. went.

(2nd pass: dehydration extrusion)
The extruder cylinder was inclinedly heated to 70° C. (upstream part) to 130° C. (downstream part), and one-pass mixture was passed through a twin-screw kneader equipped with a vent to perform dehydration extrusion. The composition ratio of the mixture after the second pass extrusion was AcNUKP/(ε caprolactam+water)/AO=(3.96+10)/32.93/1 (total total mass part: 47.89).

(3rd pass: melt kneading with PLA)
PLA powder is added to the mixture that has passed 2 passes to prepare a mixture with a composition ratio of PLA/2 pass mixture = 20/47.89, and melt-kneading with a twin-screw kneader at the cylinder temperature (150-160°C) at which PLA melts. I went. The composition ratio of the composition after extrusion was PLA/AcNUKP/(ε caprolactam+water)/AO=20/(3.96+10)/7.02/1 (total total mass part: 41.98).

(4th pass: diluted extrusion with PP/clay and MAPP)
A mixture having a composition ratio of PP/clay=51.04/5 (total composition mass part: 56.04) was pre-kneaded by biaxial kneading (cylinder temperature 170° C.), and the PP/clay mixture, MAPP and the above 3 were mixed. The passed mixture was melt-kneaded with a biaxial kneader (cylinder temperature 180-190°C) at a composition ratio of (PP/clay mixture)/MAPP/(3-pass mixture) = 56.04/10/41.98. Then, in order to remove the remaining water and ε-caprolactam, deaeration was performed by a vacuum vent. The composition ratio of the obtained composition was PP/MAPP/PLA/AcNUKP/clay/AO=51.04/10/20/(3.96+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG.

  According to the polarization microscope observation image of FIG. 5, the fiber diameter of the thick fiber was about 5 to 20 μm, and according to the electron microscope observation image, the fiber diameter of the thin fiber was about 100 to 500 nm.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 2.

(Comparative Example 1) PP molded body (non-fiber reinforced PP)
Commercially available pelletized PP was processed into a molded body (width 10 mm x length 80 mm x thickness 4 mm) at a cylinder temperature of 190°C by an injection molding machine (NPX7 type, NPX7 type, clamping force 7 tons).

(Comparative Example 2) Test number PP618 (mixed molded product of PP and PLA, non-fiber reinforced)
PP powder, PLA powder, MAPP and AO are mixed at a composition ratio of PP/PLA powder/MAPP/AO=70/20/10/1, and a twin-screw kneader (φ15 mm, L/D45: Technovel) is used. The melt-kneading was carried out by setting the kneading cylinder set temperature to 170°C. The obtained composition was processed into an injection-molded article by the same method as described above.

(Comparative Example 3) Test number PP612 (collective kneading composition)
AcNUKP (lot number (1)EY262) was slurried in isopropyl alcohol (IPA) and PLA powder and MAPP were added thereto. Then, it stirred and filtered and the filter cake was obtained. This was put into a stir drier (TX5: manufactured by Inoue Seisakusho Co., Ltd., content 5 L) together with AO, and stirred and dried. The composition ratio of the obtained mixture was PLA powder/MAPP/AcNUKP/AO=20/10/(3.5+10)/1. This mixture is called "powder MB1". Powder MB1 and PP were mixed at a ratio of PP/powder MB1=56.5/44.5 and melt-kneaded using a twin-screw kneader at a cylinder set temperature of 170°C. The composition ratio of the obtained melt-kneaded product was PP/MAPP/PLA/AcNUKP/AO=56.5/10/20/(3.5+10)/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG.

  This kneaded product was processed into an injection-molded body in the same manner as described above.

  In this specification, a method in which all the raw materials are collectively mixed, charged into a twin-screw kneader and kneaded is referred to as collective kneading, and the obtained composition is referred to as a collective kneading composition.

(Comparative Example 4) Test No. PP610 (two-stage kneading composition)
AcNUKP (lot number (1)EY262) was slurried in isopropyl alcohol (IPA) and PLA powder was added. Then, it stirred and filtered and the filter cake was obtained. This was put into a stir drier (TX5: manufactured by Inoue Seisakusho Co., Ltd., internal volume: 5 L) together with AO and stirred and dried. The composition ratio of the obtained mixture was PLA powder/AcNUKP/AO=20/(3.4+10)/1. This mixture is called "Powder MB2". Powder MB2 was melt-kneaded using a twin-screw kneader at a cylinder set temperature of 160° C. to obtain a melt-kneaded product (referred to as “MB2”). PP, MAPP and MB2 were mixed at a ratio of PP/MAPP/MB2=56.6/10/34.4 and melt-kneaded at a cylinder set temperature of 180° C. using a twin-screw kneader. The composition ratio of the obtained melt-kneaded product is PP/MAPP/PLA/AcNUKP/AO=56.5/10/20/(3.5+10)/1 as in Comparative Example 3. The composition ratio is the same as that in the above-described Example 1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope image and electron microscope image are shown in FIG.

  Further, this kneaded product was processed into an injection molded body in the same manner as described above.

  As described above, the chemically modified fiber assembly (AcNUKP) and PLA (first resin) are melt-mixed in advance, and the mixture is diluted with PP (second resin) and MAPP and melt-kneaded. The procedure is referred to herein as two-stage kneading and the resulting composition is referred to as a two-stage kneading composition.

(Comparative Example 5) Test No. PP664 (containing two-stage kneading PP composition, AcNUKP and clay)
AcNUKP (lot number (2)NT297) was slurried in isopropyl alcohol (IPA) and PLA powder was added. Then, it stirred and filtered and the filter cake was obtained. This was put into a stir drier (TX5: manufactured by Inoue Seisakusho Co., Ltd., internal volume: 5 L) together with AO and stirred and dried. The composition ratio of the obtained composition was PLA powder/Ac-NUKP/AO=20/(3.5+10)/1. This mixture is referred to as "powder MB3". Powder MB3 was melt-kneaded at a cylinder setting temperature of 160° C. using a twin-screw kneader to obtain a kneading composition (this is referred to as “MB3”).

  On the other hand, PP and clay were melt-kneaded at a mixing ratio of 51.5/5 at 170° C. using a biaxial kneader to prepare a clay-containing PP composition.

  The above clay-containing PP composition, MAPP and MB3 were mixed at a composition ratio of clay-containing PP composition/MAPP/MB3=56.5/10/34.5, and this mixture was set at a cylinder set temperature of 180 using a twin-screw kneader. Melt kneading was performed at ℃. The composition ratio of the obtained melt-kneaded product was PP/MAPP/PLA/AcNUKP/clay/AO=51.5/10/20/(3.5+10)/5/1. Note that this composition ratio is the same as that in the above-described Example 2.

  Further, this kneaded product was processed into an injection molded body in the same manner as described above.

  As described above, the composition obtained by previously performing melt mixing only with the PLA and the chemically modified fiber modified product, diluting the mixture with the separately prepared clay-containing PP composition, and melt-kneading the mixture is used. Is referred to as a two-stage kneaded PP composition (containing clay).

  A three-point bending test was performed on the molded articles of Comparative Examples 1 to 5 described above by the method described above. The results are shown in Table 3.

  From the results of the three-point bending test shown in Table 3, the following was found.

  Compared with the PP molded body (Comparative Example 1), the flexural modulus and bending strength of the molded body containing PLA (Comparative Example 2) were improved by about 10%.

  Further, in the molded product (Comparative Example 3) to which AcNUKP was further added, the bending elastic modulus was improved by 48% and the bending strength was improved by 24% as compared with the PP molded product (Comparative Example 1).

  The molded product (Comparative Example 4) of the two-step kneading composition in which the raw materials of Comparative Example 3 were added in two steps had a bending elastic modulus of 66% and a bending strength of 37% as compared with the PP molded product (Comparative Example 1). Improved.

  In the molded product obtained by adding clay to the molded product of Comparative Example 4 (Comparative Example 5), the bending elastic modulus was improved by 78% and the bending strength was improved by 34% as compared with the PP molded product (Comparative Example 1).

  In addition, the following was found from the results of the three-point bending test shown in Tables 2 and 3.

  The molded product made of the composition produced by the method of Example 1 had an improved flexural modulus of 82% and a flexural strength of 41% as compared with the molded product of PP (Comparative Example 1).

  The molded product made of the composition manufactured by the method of Example 2 had a flexural modulus improved by 112% and a flexural strength improved by 53% as compared with the PP molded product (Comparative Example 1).

  When the molded product made of the composition produced by the method of Example 1 was compared with the molded product made of the composition of Comparative Example 4 prepared without using the defibration aid ε-caprolactam, it was produced by the method of Example 1. In the molded body made of the above composition, the bending elastic modulus was improved by 470 MPa (14.4%) and the bending strength was improved by 2.1 MPa (2.9%) as compared with that of Comparative Example 4.

  Comparing Example 2 and Comparative Example 5, a molded body made of the composition produced by the method of Example 2 (using ε-caprolactam as a defibration aid) is bent with respect to the molded body of Comparative Example 5. The elastic modulus has improved by 680 MPa (19.4%) and the bending strength has improved by 10 MPa (13.9%). It can be said that this is the effect of the defibration aid (ε-caprolactam).

  Comparing the molded body of Comparative Example 4 with the molded body of Comparative Example 5 (clay added), in Comparative Example 5, the bending elastic modulus was improved by 240 MPa, but the bending strength was decreased by 1.7 MPa in Comparative Example 5. That is, it can be said that in Comparative Examples, the effect of adding clay is limited only to the flexural modulus.

  On the other hand, the results of the molded body manufactured by the method of Example 1 and the molded body manufactured by the method of Example 2 (both compositions were manufactured using ε-caprolactam as a defibration aid) were obtained. By comparison, in Example 2 in which clay was used as a defibration auxiliary agent, both the flexural modulus and the flexural strength were higher than those in Example 1 (the flexural modulus was 450 MPa and the flexural strength was 6.2 MPa).

  From these results, it can be seen that in both Examples 1 and 2, the defibration property was dramatically improved as compared with Comparative Examples 4 and 5. Further, in Example 2, it can be seen that the synergistic effect of ε-caprolactam (the defibration aid) and clay (the defibration auxiliary agent) further improved the defibration property.

  Thus, ε-caprolactam has the effect of a defibration aid that swells cellulose to improve defibration, an effect of a flocculation inhibitor that suppresses re-flocculation of defibrated AcNUKP during kneading, and PP It is considered that there is an effect of a dispersant that promotes the dispersion effect when diluted with the matrix. Further, it is clear from the results of the above bending characteristics that a synergistic effect is obtained by using clay (defibration auxiliary agent) and ε-caprolactam in combination.

(Example 3) Test number PP796 (Extrusion process modification to Example 2)
In the molded article of the composition prepared by using ε-caprolactam and clay in Example 2 above, the bending property was dramatically improved, and the dispersibility of the microfibrillated AcNUKP in the resin was improved. In Example 3, the manufacturing process of Example 2 was examined without changing the content ratio of the resin composition.

  A schematic diagram for explaining the manufacturing method of the third embodiment is shown in FIG.

  Example 3 is different from Example 2 in that (i) PLA powder was added in the first step (first pass), and (ii) cold extrusion (cylinder water cooling) in the first pass was dehydrated extrusion (cylinder). The temperature was changed to 80 to 130° C., and the second pass dehydration extrusion (cylinder temperature 70 to 130° C.) was used as ε-caprolactam/PLA swelling kneading (cylinder temperature 80° C.).

  In Example 3, AcNUKP was slurried in water, filtered, and then ε-caprolactam, PLA powder and AO were added, and a household mixer was used to prepare AcNUKP/PLA powder/ε-caprolactam/water/AO mixture, and this mixture As a first composition in the manufacturing process, a mixture was prepared by passing the mixture through a biaxial kneader for a total of 4 passes. (In addition, in Examples 1 and 2, PLA powder was not added as a composition component at the time of start.)

Hereinafter, each step shown in FIG. 8 will be described in detail.
(First pass: Dewatering extrusion)
Pass the mixture of AcNUKP (Lot number (5)T011)/PLA powder/ε-caprolactam/water/AO (3.1+10)/20/20/40/1 through a twin-screw kneader equipped with a vent. Thus, dehydration extrusion was performed. The cylinder temperature of the extruder was inclinedly heated to 80°C (upstream part) to 130°C (downstream part). Although this heating temperature is lower than the melting point of PLA (about 160° C.), PLA was swollen by ε-caprolactam, kneaded with other composition components, and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/PLA swollen material)
Kneading and extruding were carried out by passing the above-mentioned one-pass mixture through a twin-screw kneader whose extruder cylinder was set at 80°C. In the above-mentioned first pass, water was roughly removed, and in the second pass, the swelling product of ε-caprolactam and PLA and other composition components were kneaded.

(3rd pass: melt kneading with PLA)
The above-mentioned two-pass mixture was melt-kneaded in a twin-screw kneader at a cylinder temperature of 160° C. at which PLA melts. The composition ratio of the composition after extrusion was AcNUKP/PLA powder/(ε caprolactam+water)/AO=(3.1+10)/20/5.8/1 (total composition weight part: 39.9).

(4th pass: Dilution extrusion with PP/MAPP/clay kneaded material)
PP/MAPP/clay = 51.9/10/5 (total mass: 66.9) was biaxially kneaded (cylinder temperature 170°C) to obtain a PP/MAPP/clay kneaded product and the above 3 passes. The kneaded product of was melt-kneaded with a biaxial kneader (cylinder temperature 180°C-190°C) at a composition ratio (PP/MAPP/clay)/(kneaded product after 3 passes)=66.9/39.9. Then, in order to remove the remaining water and ε-caprolactam, deaeration was performed by a vacuum vent. The final composition ratio of the obtained kneaded product was PP/MAPP/PLA/AcNUKP/clay/AO=51.9/10/20/(3.1+10)/5/1 as in Example 2.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarized microscope observation image and electron microscope observation image are shown in FIG.

  The fiber diameter of the thick fibers was about 10 μm according to the polarization microscope observation image, and the fiber diameter of the thin fibers was about several tens nm to 500 nm according to the electron microscope observation image.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 4.

(Example 4) Test number PP826 (Example in which the clay of Example 3 was changed to general-purpose talc)
FIG. 10 shows the manufacturing method of the fourth embodiment. In this production method, in Example 3, clay as a defibration auxiliary agent is used as general-purpose talc (Microace MSZ-C: manufactured by Nippon Talc, average particle diameter 12.8 μm, amino-based surface-treated, hereinafter referred to simply as talc. ) Is the same as Example 3 except that it was changed to ).

(First pass: Dewatering extrusion)
A mixture with a composition ratio of AcNUKP (Lot No. (6)T014)/PLA powder/ε caprolactam/water/AO=(3.07+10)/20/20/40/1 was set at an extruder cylinder temperature of 80°C (upstream). Part) to 130° C. (downstream part), and dehydration extrusion was performed by passing the mixture through a twin-screw kneader equipped with a vent.

  Although this heating temperature is lower than the melting point of PLA (about 160° C.), PLA was swollen by ε-caprolactam, and the respective composition components were kneaded and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/PLA swollen material)
Kneading and extruding were carried out by passing the above-mentioned one-pass mixture through a twin-screw kneader whose cylinder temperature was set to 80°C. In the first pass, the water was roughly removed, and in the second pass, the swelling product of ε-caprolactam and PLA and the other composition were kneaded.

(3rd pass: melt kneading with PLA)
The mixture after two passes was melt-kneaded with a twin-screw kneader set to a cylinder temperature (160° C.) at which PLA melts. The component composition ratio of the kneaded product after extrusion was AcNUKP/PLA powder/ε caprolactam+water/AO=(3.07+10)/20/3.77/1 (total mass part of kneaded product: 37.84).

(4th pass: Dilution extrusion with PP/MAPP/talc kneaded material)
Ingredient composition ratio PP/MAPP/talc = 51.93/10/5 (total 66.93) PP/MAPP/talc kneaded product obtained by previously kneading with biaxial kneading (cylinder temperature 170°C) and the above 3 The kneaded product after passing was biaxially kneaded (cylinder temperature 180° C.) at a composition ratio of (PP/MAPP/talc)/3-pass kneaded product=66.93/37.84. Then, in order to remove the remaining water and ε-caprolactam, deaeration was performed by a vacuum vent. The composition ratio of the obtained kneaded composition was PP/MAPP/PLA/AcNUKP/talc/AO=51.93/10/20/(3.07+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope image are shown in FIG.

  The fiber diameter of the thick fibers was about 5 to 10 μm according to the polarization microscope observation image, and the fiber diameter of the thin fibers was about several tens nm to 500 nm according to the electron microscope observation image.

  In addition, in the polarization microscope observation image of the resin composition produced by the production method of Example 3 (the extrusion process of Example 2 was changed), white mist-like regions corresponding to microfibrillated AcNUKP increased (FIG. 9). Furthermore, by using talc instead of clay (Example 4), the dark white streaks corresponding to the fibers that were insufficiently defibrated were significantly reduced (FIG. 11).

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 4.

  From the results shown in Tables 3 and 4, the molded product of Example 3 has improved flexural modulus of 132% and flexural strength of 62% compared to the molded product made of only PP (Comparative Example 1). The molded product of Example 4 had an improved flexural modulus of 129% and a flexural strength of 69% as compared to the molded product of PP alone (Comparative Example 1).

  From the results of Table 2 and Table 4, the bending elastic modulus of the molded body made of the composition manufactured by the manufacturing method of Example 3 was changed by changing the manufacturing method of Example 3 from Example 2 as described above. It can be seen that, in comparison with that of the molded body made of the composition manufactured by the method of Example 2, the bending strength increased by 390 MPa and the bending strength improved by 4.8 MPa.

  In addition, by changing the defibration auxiliary agent used from clay (Example 3) to general-purpose talc (Example 4), the bending strength was significantly improved (4 MPa).

  From the above, by mixing PLA together with a defibration aid (ε-caprolactam) as a composition component in the first step (first pass), the kneaded product of ε-caprolactam and PLA is defibrated by AcNUKP. It is considered that the flexural modulus and flexural strength are improved by exerting the above effect. It was also revealed that low-cost talc could be used instead of clay.

(Example 5) Test number PP864 (blending of raw materials)
In Example 3, dehydration was performed in the first pass of the extruder, and ε-caprolactam/PLA swelling kneading was effective in the second pass. In Example 4, it was suggested that general-purpose talc exhibits a reinforcing effect more than that of clay. It was Therefore, the following Example 5 was carried out with the aim of further improving the physical properties and simplifying the manufacturing process.

  Specifically, Example 5 aims to improve the dispersibility by the interaction between the raw materials and to omit the PP/MAPP/talc melt-kneading step employed in the manufacturing methods of Examples 3 and 4. All the raw materials except PP were mixed and used at the beginning of the manufacturing process.

  FIG. 12 shows a schematic diagram for explaining the manufacturing method of the fifth embodiment.

  In Example 4 above, the starting material (raw material used at the beginning of the process) is a mixture of AcNUKP/PLA powder/ε-caprolactam/water/AO, but in Example 5 a mixture of all raw materials other than PP ( Composition ratio: AcNUKP (Lot number (7)T025)/PLA powder/MAPP/talc/ε-caprolactam/water/AO=(3.01+10)/20/10/5/20/40/1)) as the starting material did.

Hereinafter, each step shown in FIG. 12 will be described in detail.
Preparation of raw material mixture (starting material):
AcNUKP (lot number (7)TO25, DS0.64) was slurried in water, filtered, then ε-caprolactam, PLA powder, MAPP, talc and AO were added, and the composition ratio AcNUKP/PLA/MAPP was added using a household mixer. A mixture of /talc/ε caprolactam/water/AO=(3.01+10)/20/10/5/20/40/1 was made. In Examples 5 and 6, this mixture was used as the starting material in the first step.

(First pass: Dewatering extrusion)
The raw material mixture was dehydrated and extruded by heating the cylinder at an inclined temperature of 80° C. (upstream portion) to 130° C. (downstream portion) and passing it through a biaxial kneader provided with a vent. Although the heating temperature is lower than the melting point of PLA (about 160° C.), PLA was swelled with ε-caprolactam, and the raw material mixture was kneaded and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/PLA swollen material)
Kneading and extruding was carried out by passing the mixture through one pass through a twin-screw kneader with the cylinder set at 80°C. In the first pass, the water was mostly removed, and the other materials were kneaded with the swollen product of ε-caprolactam and PLA.

(Third pass: melt kneading of PLA)
The above kneaded product after two passes was melt-kneaded by a biaxial kneader at a cylinder temperature of 160° C. at which PLA melts. The composition after extrusion was AcNUKP/PLA/MAPP/talc/ε-caprolactam+water/AO=(3.01+10)/20/10/5/19.36/1 (total composition mass part: 68.37).

(4th pass: Dilution extrusion with PP)
PP was mixed with the above-mentioned melt-kneaded product after 3 passes to obtain a mixture having a composition mixing ratio of (mixture after 3 passes)/PP=68.37/51.99, which was melt-kneaded with a twin-screw kneader ( Cylinder temperature 180℃). Then, in order to remove the remaining water and ε-caprolactam, deaeration was performed by a vacuum vent. The composition ratio of the obtained resin composition was PP/MAPP/PLA/AcNUKP/talc/AO=51.99/10/20/(3.01+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. The fiber diameter of the thick fibers was about 5 to 10 μm according to the polarization microscope observation image, and the fiber diameter of the thin fibers was about several tens nm to 1 μm according to the electron microscope observation image.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 5.

(Example 6) Test number PP873 (steps omitted)
FIG. 14 is a schematic diagram illustrating the manufacturing method of the sixth embodiment.

  In Example 6, in order to further improve the physical properties and simplify the manufacturing process, a mixture of all raw materials other than PP was used at the beginning of the process as in Example 5 to remove water and ε-caprolactam from the composition. Also, the diluting and kneading process with PP resin was changed from 4 passes to 3 passes. That is, the third pass (PLA melting and kneading step (160° C.)) in the manufacturing methods of Examples 3, 4, and 5 was omitted. The chemically modified lignopulp (AcNUKP) used is serial number (7) TO25 (DS0.64).

Hereinafter, each step shown in FIG. 14 will be described in detail.
(First pass: Dewatering extrusion)
Prepared in the same manner as in Example 5, the composition ratio was AcNUKP (lot number (7)T025)/PLA/MAPP/talc/ε caprolactam/water/AO=(3.01+10)/20/10/5/20. The mixture of /40/1 was subjected to dehydration extrusion by heating the mixture with a cylinder temperature inclined from 80°C (upstream part) to 130°C (downstream part) and passing it through a biaxial kneader equipped with a vent. Although the temperature was lower than the melting point of PLA (about 160° C.), PLA was swollen by ε-caprolactam, and the above mixture was kneaded and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/PLA swollen material)
The one-pass mixture was passed through a twin-screw kneader whose cylinder temperature was set to 80° C. to carry out kneading extrusion. Most of the water was removed on the first pass. The composition ratio of the kneaded product after 2 passes is AcNUKP/PLA/MAPP/talc/(ε caprolactam+water)/AO=(3.01+10)/20/10/5/20.36/1 (total composition mass part: 69.37 )Met.

(Third pass: Dilute extrusion with PP)
PP is added to the kneaded product after the above 2 passes to make a mixture with a composition ratio of (the above kneaded product after 2 passes)/PP=69.37/51.99, and this is melt kneaded with a twin-screw kneader (cylinder temperature 180°C) And degassed by vacuum vent to remove residual water and ε-caprolactam. The composition of the obtained resin composition was PP/MAPP/PLA/AcNUKP/talc/AO=51.99/10/20/(3.01+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. The fiber diameter of the thick fibers was 5 μm or less according to the polarization microscope observation image, and the fiber diameter of the thin fibers was several tens nm to 500 nm according to the electron microscope observation image.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 5.

  From Table 5, the bending elastic modulus and bending strength of the molded body of Example 5 manufactured by mixing all the raw materials other than PP at the beginning of the manufacturing process were equal to or higher than those of Example 4.

  Furthermore, the bending elastic modulus of the molded body manufactured in Example 6 by simplifying the manufacturing process was 4866 MPa, and the bending strength was 96.9 MPa, which showed high strength characteristics.

  From the results of Table 3 and Table 5, the following was found.

  The flexural modulus of the molded product manufactured by the method of Example 5 was 131% higher than that of the molded product made of PP alone (Comparative Example 1), and the flexural strength was 72% higher.

  The flexural modulus of the molded product produced by the method of Example 6 was 146% higher and the flexural strength was 80% higher than that of the molded product made of only PP (Comparative Example 1).

  As described above, in Example 5, the production method of Example 4 was improved, and all raw materials other than PP were kneaded at the beginning of the production process. In Example 6, the process of removing water and ε-caprolactam from the composition was further changed from 4 passes to 3 passes to simplify the process. By the above improvement of the production method, the strength characteristics of the produced molded article were further improved, and the fiber diameter of AcNUKP dispersed in the composition was also dramatically reduced. Further, it was found that the cost reduction of the resin composition and the molded product made of the resin composition can be expected by simplifying the process (Example 6).

  Here, when Examples 1 to 6 are summarized, ε-caprolactam is used as a defibration aid to defibrate chemically modified pulp (AcNUKP), and first, chemically modified MFC (microfibrillated AcNUKP) and PLA are combined. A method for producing a composition in which microfibrillated AcNUKP is dispersed in a thermoplastic resin (PLA and PP) by preparing a complex and then complexing it with PP. That is, in Examples 1 to 6, first, a PLA composition containing a chemically modified MFC was prepared as a masterbatch, which was diluted with PP to prepare a thermoplastic mixed resin containing the chemically modified MFC (a mixture of PLA and PP). A resin) composition is prepared.

(Example 7) Test number PP800
In Example 7, PA6 was used instead of PLA, and a resin composition containing chemically modified MFC, PA6 and PP was produced. The materials used are as described above.

  FIG. 16 is a schematic diagram illustrating the manufacturing method of the seventh embodiment.

  Mix all raw materials except PP in the mixing ratio: AcNUKP (lot number (8)T011)/PA6 powder/MAPP/ε caprolactam/water/AO=(3.1+10)/20/10/20/40/1 This mixture was used as the starting material (starting material).

Hereinafter, each step shown in FIG. 16 will be described in detail.
(First pass: Dewatering extrusion)
Dehydration extrusion was carried out by heating the above-mentioned starting material with a cylinder temperature set to 80° C. (upstream part) to 130° C. (downstream part) in an inclined manner and passing it through a biaxial kneader equipped with a vent.

(2nd pass: kneading of ε-caprolactam/PA6 swollen material)
Kneading and extruding was carried out by passing the above-mentioned one-pass mixture through a twin-screw kneader in which the cylinder was inclinedly heated to 130° C. (upstream part) to 180° C. (downstream part). Water was removed in the first pass, and the other materials were kneaded with the swollen product of ε-caprolactam and PA6.

(3rd pass: PA6 melt kneading)
The obtained kneaded product after 2 passes was melt-kneaded with a biaxial kneader having a cylinder temperature of 170 to 180°C. The composition ratio after kneading was AcNUKP/PA6/MAPP/ε caprolactam+water/AO=(3.1+10)/20/10/6.72/1 (total composition mass part: 50.82).

(4th pass: Dilution extrusion with PP)
PP is mixed with the obtained kneaded product after three passes to prepare a composition of (three-passed mixture)/PP=50.82/56.9, which is biaxially kneaded at a cylinder temperature of 180°C to 190°C and left. Degassing was performed with a vacuum vent to remove water and ε-caprolactam. The composition ratio of the obtained resin composition was PP/MAPP/PA6/AcNUKP/AO=56.9/10/20/(3.01+10)/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. The fiber diameter of the thick fibers was 10 μm or less according to the polarization microscope observation image, and the fiber diameter of the thin fibers was several tens nm to 1 μm according to the electron microscope observation image.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 6.

(Example 8) Test number PP880
The manufacturing method of Example 8 is the same as that of Example 6 except that PA6 was used in place of the PLA used in Example 6.

  FIG. 18 shows a schematic diagram illustrating the manufacturing method of Example 8.

  AcNUKP (lot number (9)T031)/PA6 powder/MAPP/talc/ε caprolactam/water/AO=(3.15+10)/20/10/5/20/40/1 for all raw materials except PP Were mixed at a mixing ratio of and used as a starting material.

Hereinafter, each step shown in FIG. 18 will be described in detail.
(First pass: Dewatering extrusion)
The starting material was dehydrated and extruded by heating the starting material in a kneader cylinder at an inclined temperature of 80° C. (upstream part) to 180° C. (downstream part) and passing it through a biaxial kneader provided with a vent. Although the set temperature is lower than the melting point of PA6 (about 225° C.), PA6 was swollen with ε-caprolactam, the mixture of the starting materials was kneaded, and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/PA6 swollen material)
The kneading and extruding was performed by passing the kneaded product after one pass through a twin-screw kneader in which the kneader cylinder was set at 155°C. In the 1st pass, water was mostly removed, and the swollen product of ε-caprolactam and PA6 and other components were kneaded, but in the 2nd pass, the remaining water and ε-caprolactam were discharged. The composition ratio of the kneaded product after 2 passes is AcNUKP/PA6/MAPP/talc/(ε caprolactam+water)/AO=(3.15+10)/20/10/5/12.94/1 (total composition is 62.09). )Met.

(Third pass: Dilute extrusion with PP)
PP is mixed with the kneaded product after 2 passes to make a mixture having a composition ratio of (2 pass mixture)/PP=62.09/51.85, and this is melt-kneaded with a twin-screw kneader with a cylinder temperature of 200° C. to obtain the remaining water. Degassing was performed with a vacuum vent to remove ε-caprolactam. The composition ratio of the obtained melt-kneaded product was PP/MAPP/PA6/AcNUKP/talc/AO=51.85/10/20/(3.15+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarized microscope observation image and electron microscope observation image are shown in FIG. The diameter of the thick fibers was 10 μm or less according to the polarization microscope image, and the diameter of the thin fibers was about several tens nm to 1 μm according to the electron microscope image.

  Further, comparing the polarizing microscope image of Example 7 in FIG. 17 with the polarizing microscope image of Example 8 in FIG. 19, the polarizing microscope image of Example 8 has a large fiber length and corresponds to microfibrillated AcNUKP. The area of the white mist-like image was large.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 6.

(Comparative Example 6) PA6 molded product A commercially available PA6 pellet was used as it was, the cylinder temperature of the injection molding machine was set to 230°C, and the injection molded product was processed in the same manner as described above.

  The obtained molded body (test piece) was subjected to a three-point bending test by the above method. The results are shown in Table 7.

(Comparative Example 7) Test number PP494 (AcNBKP, PA6 and PP-containing composition)
AcNBKP (lot number (8)Mb-c73-77) was slurried in isopropyl alcohol (IPA) and PA6 powder, MAPP and PP powder were added. Then, it stirred and filtered and the filter cake was obtained. This is put into a stir dryer (TX5: Inoue Seisakusho Co., Ltd., content 5L), stirred and dried, and the composition ratio is PA6 powder/MAPP/PP powder/AcNBKP=10/10/1.6/(1.73+10) mixture. (This is called "powder MB4"). The powders MB4, PP and PA6 were mixed at a ratio of PP/PA6 powder/powder MB4=56.1/9.9/33 and melt-kneaded using a twin-screw kneader having a cylinder temperature of 170°C. Thus, the mixture prepared by mixing all the raw materials at once was melt-kneaded by the biaxial kneader. The composition ratio of the obtained kneaded product was PP/MAPP/PA6/AcNBKP=57.7/10/20/(1.73+10).

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 7.

  From the results of Tables 6 and 7, it can be seen that the molded body prepared by the method of Example 7 using ε-caprolactam and PA6 was superior in bending elastic modulus and bending strength to the molded body of Comparative Example 7. .. Further, the molded body prepared by the manufacturing method of Example 8 in which talc was used together and the manufacturing process was simplified showed high strength characteristics of a bending elastic modulus of 4210 MPa and a bending strength of 90.3 MPa.

  From the results of Table 3 and Table 6, when the bending elastic modulus and bending strength of the molded body of Example 7 were compared with those of the PP molded body (Comparative Example 1), the bending elastic modulus was improved by 90% and the bending strength was improved by 66%. I understand. It can be seen that in the molded body of Example 8, the bending elastic modulus is improved by 114% and the bending strength is improved by 68% as compared with the PP molded body (Comparative Example 1).

(Comparative example 8) Test number PP766
A melt-kneaded composition containing AcNUKP and a thermoplastic resin (PP and PLA) and a molded product formed from the same were produced in the same manner as in Example 2 except that the defibration aid (ε-caprolactam) was not used.

  The outline of the manufacturing method is as follows.

  First, AcNUKP (Lot No. (10)NT298) is slurried in water, AO is added after filtration, a mixture of AcNUKP/water/AO is made with a household mixer, and this mixture is used as a starting material in a twin-screw kneader. The composition of Comparative Example 8 was obtained by passing a total of 4 passes.

  The method for producing the composition of Comparative Example 8 is shown in FIG.

  Hereinafter, each step shown in FIG. 21 will be described in detail.

(First pass: cold extrusion)
The AcNUKP (Lot number (10)NT298)/water/AO=(3.86+10)/40/1 mixture was cold extruded using a twin screw kneader with water cooled cylinder.

(2nd pass: dehydration extrusion)
The extruder cylinder was inclinedly heated to 70° C. (upstream part) to 130° C. (downstream part), and one-pass mixture was passed through a twin-screw kneader equipped with a vent to perform dehydration extrusion. The composition of the mixture after the second pass extrusion was AcNUKP/water/AO=(3.86+10)/0/1 (total total weight part 14.86).

(3rd pass: melt kneading with PLA)
PLA powder is added to the mixture that has passed through 2 passes to prepare a mixture with a composition ratio of PLA/2 pass mixture = 20/14.86, and melt-kneading with a twin-screw kneader at the cylinder temperature (150-160°C) at which PLA melts. I went. The composition ratio after extrusion was PLA/AcNUKP/water/AO=20/(3.86+10)/0/1 (total total mass part: 34.86).

(4th pass: diluted extrusion with PP/clay and MAPP)
A mixture having a composition ratio of PP/clay=51.14/5 (total mass part of composition: 56.14) was previously kneaded by biaxial kneading (cylinder temperature 170° C.) to obtain a PP/clay kneaded product. This kneaded product, MAPP, and the mixture of 3 passes are melt-kneaded by biaxial kneading (cylinder temperature 180°C) at a composition ratio of (PP/clay kneading product)/MAPP/(3 pass mixture) = 56.14/10/34.86. did. Then, in order to remove the remaining water, deaeration was performed by a vacuum vent. The composition ratio of the obtained composition was PP/MAPP/PLA/AcNUKP/clay/AO=51.14/10/20/(3.86+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG.

  According to the polarization microscope observation image of FIG. 22, the fiber diameter of the thick fiber was about 5 μm, and according to the electron microscope observation image, the fiber diameter of the thin fiber was several tens nm to 1 μm. In addition, it was found that the fibers in FIG. 22 were significantly disintegrated, but the fiber shortening was remarkable.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 8.

  Comparing Table 2 and Table 8, the molded article of Comparative Example 8 has a bending elastic modulus of 1 GPa and a bending strength of 110 MPa or more lower than those of Example 2 (test number PP717). The molded product of Comparative Example 8 to which ε-caprolactam was not added was significantly inferior in physical properties as compared with Comparative Example 5 (Table 3). In Comparative Example 8, it is considered that one of the reasons why the reinforcing effect of the fiber of the molded body is not obtained is the remarkable shortening of the fiber.

  The above shows that a resin composition (molded product) having good physical properties cannot be obtained unless a defibrating agent (ε caprolactam) is used. That is, from the comparison between Example 2 and Comparative Example 8, it can be seen that the effect of the defibrating agent (ε-caprolactam) is remarkable.

(Example 9) Test number PP1172
The manufacturing method of Example 9 is the same as that of Example 8 except that PA6 used in Example 8 was not used as the resin, and AcTUKP was used instead of AcNUKP as the chemically modified pulp.

  FIG. 23 shows a schematic diagram illustrating the manufacturing method of Example 9.

  Mix all raw materials except PP at a mixing ratio of AcTUKP (lot number (11)T081)/MAPP/talc/ε-caprolactam/water/AO=(2.13+10)/10/5/20/20.4/1) And used this as the starting material.

Hereinafter, each step shown in FIG. 23 will be described in detail.
(First pass: dehydration extrusion)
The above starting material was dehydrated and extruded by heating the kneading machine cylinder at an angle of 90° C. (upstream part) to 150° C. (downstream part) and passing it through a biaxial kneading machine provided with a vent. Although the above set temperature is low as the processing temperature of MAPP, MAPP was swollen by ε-caprolactam, the mixture of the above starting materials was kneaded, and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/MAPP swollen material)
The kneading and extruding was performed by passing the kneaded material after one pass through a twin-screw kneader in which the kneader cylinder was set at 130°C. In the 1st pass, water was mostly removed, and the swollen product of ε-caprolactam and MAPP and other components were kneaded, but in the 2nd pass, the remaining water and ε-caprolactam were discharged. The composition ratio of the kneaded product after 2 passes was AcTUKP/MAPP/talc/(ε caprolactam+water)/AO=(2.13+10)/10/5/17.38/1 (total composition mass part is 45.51) ..

(Third pass: Dilute extrusion with PP)
PP is mixed with the kneaded product after 2 passes to make a mixture having a composition ratio of (2 pass mixture)/PP=45.51/72.87, and this is melt-kneaded with a twin-screw kneader having a cylinder temperature of 180° C. to obtain the remaining water. Degassing was performed with a vacuum vent to remove ε-caprolactam. The composition ratio of the obtained melt-kneaded product was PP/MAPP/AcTUKP/talc/AO=72.87/10/(2.13+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarized light microscope image, the fiber diameter of the thick fiber was about 10 μm, and according to the electron microscope image, the fiber diameter of the thin fiber was about several tens nm to 1 μm.

  A test piece (molded body) was produced from the obtained composition according to the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 9.

(Comparative example 9) Test number PP304
AcNBKP (Lot number (12) Mb-c6-3)/PP/MAPP=(1.51+10)/78.49/10 were mixed at a composition ratio, and the kneading cylinder set temperature was 170°C using a twin-screw kneader. Was melt-kneaded.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarized light microscope image, the fiber diameter of the thick fiber was about 20 to 30 μm, and according to the electron microscope image, the fiber diameter of the thin fiber was several tens of nm to 3 μm.

  A test piece (molded article) was prepared from the composition of Comparative Example 9 in the same manner as above, and a three-point bending test was conducted by the above method. The results are shown in Table 10.

A polarization microscope observation image of Example 9 (FIG. 24), a polarization microscope observation image of Example 6 (using PLA in addition to MAPP), and an Example 8 (using PA6 in addition to MAPP) When compared with the image observed with a polarization microscope (FIG. 19), the observed image of Example 9 (FIG. 24) had a larger fiber diameter, and it appeared that the dispersibility of the fibers in the resin decreased.
On the other hand, comparing the polarization microscope observation image of Example 9 (FIG. 24) with the polarization microscope observation image (FIG. 25) of the composition shown in Comparative Example 9 (the composition produced without using ε-caprolactam), It was observed that in the observation image of 9, the dispersibility of the fiber was improved. From this, the dispersibility of the fibers in the composition of Example 9 prepared by using ε-caprolactam as the defibration aid is superior to that of the composition prepared by the usual kneading method (Comparative Example 9). It was confirmed.

  Regarding the physical properties of the molded article, from the results of Table 5, Table 6 and Table 9, a molded article prepared by mixing MAPP and PLA (Example 6) or a molded article prepared by mixing MAPP and PA6 ( Comparing Example 8) with the molded body of Example 9, it can be seen that the bending characteristics of Example 9 are lower than those of Example 6 or Example 8. From the results of Table 9 and Table 10, when the bending characteristics of Example 9 are compared with the molded body (Comparative Example 9) prepared without using ε-caprolactam (defibration aid), the bending characteristics of Example 9 are as follows. It can be seen that the bending characteristics are dramatically improved over the bending characteristics of Comparative Example 9.

(Example 10) Test number PA6-617
FIG. 26 shows a schematic view illustrating the manufacturing method of Example 10.

  In the manufacturing method of Example 10, PA6 was used instead of MAPP and PP of Example 9. First, the non-hydrated AcTUKP and PA6 were mixed and this mixture was used as the starting material. The mixing ratio of the starting materials is AcTUKP (lot number (13) manufactured by Nippon Paper Industries Co., Ltd.)/PA6/ε caprolactam=(1.41+10)/21.92/10.

  The production method of Example 10 was carried out by melt-kneading the mixture of AcTUKP and PA6 in the first pass to disperse AcTUKP in PA6, and then adding PA6 in the second pass so that the cellulose fiber content was 10%. It is a method of diluting and kneading. In Example 10, by making the starting material water-free, the first-pass dehydration extrusion step in Example 9 was omitted, and the number of extruder passes was reduced to a total of 2 as compared with the method of Example 9. ..

Hereinafter, each process shown in FIG. 26 will be described in detail.
(1st pass: kneading of ε-caprolactam/PA6 mixture)
The above starting material was kneaded and extruded by passing it through a twin-screw kneader in which the kneader cylinder was set to 165°C. Although this set temperature is low as the processing temperature of PA6, PA6 was swollen by ε-caprolactam, the mixture of the above starting materials was kneaded, and discharged in an integrated state. The composition ratio of the kneaded product was AcTUKP/PA6/ε caprolactam=(1.41+10)/21.92/10 (total composition mass part: 43.33). This was washed with warm water at 50° C. to remove ε-caprolactam.

(2nd pass: dilution with PA6, extrusion)
PA6 is mixed with the kneaded product after 1-pass washing to make a mixture with a composition ratio of (1 pass washed mixture)/PA6=33.33/66.66, and this is melt-kneaded with a twin-screw kneader with a cylinder temperature of 200 to 215°C. did. The composition ratio of the obtained melt-kneaded product is PA6/AcTUKP=88.59/11.41.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarized light microscope image, the fiber diameter of the thick fiber was about 5 to 10 μm, and according to the electron microscope image, the fiber diameter of the thin fiber was about several tens nm to 1 μm.

  A test piece (molded body) was produced from the composition of Example 10 under the conditions described above, and the test piece was subjected to a three-point bending test by the method described above. The results are shown in Table 11.

(Comparative example 10) Test number PA6-614
Non-hydrous AcTUKP and PA6 as starting materials are mixed at a composition ratio of AcTUKP (Lot No. (13) made by Nippon Paper Industries Co., Ltd.)/PA6=(1.41+10)/21.92, and the kneading cylinder setting of the biaxial kneader is set. The temperature was set to 200° C. and the mixture was melt-kneaded. This was diluted 3 times with PA6 and kneaded to obtain a melt-kneaded product (composition ratio PA6/AcTUKP=88.59/11.41, containing 10% as cellulose fiber).

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarization microscope image and the electron microscope image, the fiber diameter of the thick fiber was about 10 to 20 μm, and the fiber diameter of the thin fiber was about several tens nm to 1 μm.

  A test piece (molded article) was produced from the composition of Comparative Example 10 according to the method described above, and the test piece was subjected to a three-point bending test by the method described above. The results are shown in Table 12.

  When the polarizing microscope observation image of Example 10 (FIG. 27) and the polarizing microscope observation image of Comparative Example 10 (FIG. 28) are compared, the dispersibility of the fibers in the composition of Comparative Example 10 is clearly poor, and the short fibers In the composition of Example 10, the dispersibility of the fibers was obviously improved.

  Regarding the physical properties of the molded product, from the results of Table 11 and Table 12, the bent physical properties of the molded product of Example 10 are those of the molded product produced without using ε-caprolactam (defibration aid) shown in Comparative Example 10. It can be seen that it has improved dramatically than the sex.

(Example 11) Test number POM-169
The manufacturing method of Example 11 is different from the manufacturing method of Example 9 in that POM is used instead of MAPP and PP, and AO and talc are not used.

  FIG. 29 is a schematic diagram illustrating the manufacturing method of Example 11.

  The raw materials were mixed in a mixing ratio of AcTUKP (lot number (14)T072)/POM/ε caprolactam/water=(2.1+10)/21.23/20/25, which was used as the starting material.

Hereinafter, each step shown in FIG. 29 will be described in detail.
(First pass: Dewatering extrusion)
The above starting material was dehydrated and extruded by heating the kneading machine cylinder at an angle of 90° C. (upstream part) to 140° C. (downstream part) and passing it through a biaxial kneading machine provided with a vent. In this step, POM was swollen with ε-caprolactam, and the mixture of the above-mentioned starting materials was kneaded and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/POM swollen material)
The kneading and extruding was performed by passing the kneaded material after one pass through a twin-screw kneader having a kneading machine cylinder set at 140°C. Most of the water was removed in the first pass, but residual water and ε-caprolactam were discharged in the second pass. The composition ratio of the kneaded product after two passes was AcTUKP/POM/(ε caprolactam+water)=(2.1+10)/21.23/19.81 (total composition mass part 53.14).

(Third pass: Dilution extrusion with POM)
POM is mixed with the kneaded product after 2 passes to make a mixture with a composition ratio of (2 pass mixture)/PP=53.14/66.66, and this is melted with a twin-screw kneader that is inclinedly heated to a cylinder temperature of 160 to 170°C. After kneading and removing residual water and ε-caprolactam, deaeration was performed by a vacuum vent. The composition ratio of the obtained melt-kneaded product was POM/AcTUKP=87.89/(2.1+10).

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarized light microscope image, the fiber diameter of the thick fiber was about 5 to 10 μm, and according to the electron microscope image, the fiber diameter of the thin fiber was several tens of nm to 2 μm.

  A test piece (molded body) was produced from the obtained composition according to the method described above, and the test piece was subjected to a three-point bending test by the method described above. The results are shown in Table 13.

(Comparative Example 11) Test number POM-170
AcTUKP (lot number (15)T073)/POM=(1.97+10)/88.02 at a composition ratio of AcTUKP and POM are mixed, and the kneading cylinder set temperature is set to 160 to 170°C using a twin-screw kneader. It was set and melt-kneaded.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of the fibers in the sample was observed with the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. The fiber diameter of the thick fibers was 50 μm or more according to the polarization microscope image, and the fiber diameter of the thin fibers was several tens nm to 5 μm according to the electron microscope image.

  A test piece (molded article) was produced from the composition of Comparative Example 11 under the conditions described above, and the test piece was subjected to a three-point bending test by the method described above. The results are shown in Table 14.

  By comparing FIG. 30 with FIG. 31, the composition of Example 11 was found to have improved dispersibility of the fibers in the composition, as compared with Comparative Example 11 (manufacturing method not using ε-caprolactam).

  Regarding the physical properties of the molded body, from the results of Tables 13 and 14, it can be seen that the bending characteristics of the molded body of Example 11 are dramatically improved as compared with the bending characteristics of Comparative Example 11.

(Example 12) Test number PE198
As the chemically modified pulp, the same starting material as in Example 9 was used except that AcTUKP (lot number (15)T073) was used instead of AcTUKP (lot number (11)T081). Then, the composition of Example 12 was produced in the same process as in Example 9 except that high-density polyethylene (HDPE) was used instead of PP in the third pass.

  FIG. 32 is a schematic view illustrating the manufacturing method of Example 12.

Hereinafter, each step shown in FIG. 32 will be described in detail.
(First pass: dehydration extrusion)
As a starting material, a mixture having a mixture ratio of AcTUKP (lot number (15)T073)/MAPP/talc/ε-caprolactam/water/AO=(1.97+10)/10/5/20/25/1 was used. This starting material was passed through a twin-screw kneader equipped with a vent under the same temperature conditions as in Example 9 to carry out dehydration extrusion. MAPP was swollen by ε-caprolactam, and the above starting material was kneaded and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/MAPP swollen material)
The 1-pass kneaded product was passed through a biaxial kneader under the same conditions as in Example 9 to carry out kneading and extrusion, and water and ε-caprolactam in the kneaded product were discharged. The composition ratio of the kneaded product after 2 passes was AcTUKP/MAPP/talc/(ε caprolactam+water)/AO=(1.97+10)/10/5/17.25/1 (total composition mass part is 45.22) ..

(Third pass: Dilute extrusion with HDPE)
HDPE is mixed with the kneaded product after 2 passes to make a mixture with a composition ratio of (2 pass passed mixture)/HDPE=45.22/73.03, and this is melt-kneaded with a twin-screw kneader with a cylinder temperature of 140°C and remains. Degassing was performed with a vacuum vent to remove water and ε-caprolactam. The composition ratio of the obtained melt-kneaded product was HDPE/MAPP/AcTUKP/talc/AO=73.03/10/(1.97+10)/5/1.

  From the obtained melt-kneaded composition, a sample for microscopic observation was prepared according to the above conditions, and the state of the fibers in the sample was observed with the polarizing microscope and the electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. The fiber diameter of the thick fiber was about 30 μm according to the polarization microscope image, and the fiber diameter of the thin fiber was about several hundred nm to 1 μm according to the electron microscope image.

  A test piece (molded body) was produced from the obtained composition of Example 12 under the conditions described above, and the test piece was subjected to a three-point bending test by the method described above. The results are shown in Table 15.

(Comparative Example 12) Test number PE196
Each component of the starting material is mixed at a composition ratio of AcTUKP (lot number (15)T073)/HDPE/MAPP/talc/AO=(1.97+10)/72.03/10/5/1, and a twin-screw kneader Was melted and kneaded by setting the kneading cylinder set temperature to 140°C.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. 34. The polarization microscope image showed that the diameter of the thick fiber was about 50 μm, and the electron microscope image showed that the diameter of the thin fiber was about several hundred nm to 10 μm.

  A test piece (molded body) was prepared from the composition of Comparative Example 12 under the above conditions, and the test piece was subjected to a three-point bending test by the above method. The results are shown in Table 16.

  Comparing FIG. 33 with FIG. 34, the composition of Example 12 showed good dispersibility of the fibers in the composition, as compared with the composition of Comparative Example 12. From this, the dispersibility of the fibers in the composition of Example 12 prepared by using ε-caprolactam (defibration aid) is higher than that of the composition of Comparative Example 12 (method not using ε-caprolactam). It was confirmed to be excellent.

  Regarding the physical properties of the molded product, from the results of Tables 15 and 16, the molded product of Example 12 has dramatically improved bending properties as compared with the molded product of Comparative Example 12.

(Example 13) Test number PE190
A talc-free high density polyethylene (HDPE) composition was prepared in the same manner as in Example 12.

  The difference from Example 12 is that the starting material does not contain talc, and the AcTUKP used has a slightly higher Ac-modified DS.

  The composition ratio of the starting material was AcTUKP (lot number (14)T072)/MAPP/ε caprolactam/water/AO=(2.1+10)/10/20/25/1.

Each step will be described below.
(First pass: Dewatering extrusion)
The above starting material was passed through a twin-screw kneader equipped with a vent under the same temperature conditions as in Example 12 to carry out dehydration extrusion.

(2nd pass: kneading of ε-caprolactam/MAPP swollen material)
Kneading and extruding were performed under the same conditions as in Example 12 through the kneaded product after one pass. The composition ratio of the kneaded product after 2 passes was AcTUKP/MAPP/(ε caprolactam+water)/AO=(2.1+10)/10/17.85/1 (total composition mass part is 40.95).

(Third pass: Dilute extrusion with HDPE)
HDPE is mixed with the above kneaded product after 2 passes to obtain a mixture having a composition ratio of (2 pass mixture)/HDPE=40.95/77.9. In order to remove the above, degassing was performed by a vacuum vent. The composition ratio of the obtained melt-kneaded product was HDPE/MAPP/AcTUKP/AO=77.9/10/(2.1+10)/1.

  A sample for microscopic observation was prepared from the obtained composition under the same conditions as in Example 12, and the state of fibers in the sample was observed with a polarizing microscope and an electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarized light microscope image, the fiber diameter of the thick fiber was about 10 to 20 μm, and according to the electron microscope image, the fiber diameter of the thin fiber was several tens of nm to 5 μm.

  A test piece (molded article) was produced from the composition of Example 13 in the same manner as in Example 12, and the test piece was subjected to the three-point bending test in the same manner as in Example 12. The results are shown in Table 17.

  Comparison between FIG. 33 and FIG. 35 revealed that the fiber dispersibility in Example 13 was slightly lower than that of the composition of Example 12 (composition containing 5% talc and AcTUKP). From this result, it was found that talc acts as a defibration adjunct.

  Regarding the physical properties of the molded body, from the results of Tables 15 and 17, the physical properties of the molded body of Example 13 were the same as those of Example 12.

(Example 14) Test number PE200
A resin composition containing PLA and high-density polyethylene (HDPE) as a resin was produced in the same manner as in Example 12, except that the starting material of Example 12 to which PLA was added was used as the starting material of Example 14.

  A schematic diagram for explaining the manufacturing method of Example 14 is shown in FIG.

  The mixing ratio of the starting materials was AcTUKP (lot number (11)T081)/MAPP/PLA/talc/ε-caprolactam/water/AO=(2.13+10)/10/20/5/20/19.1/1 ..

Hereinafter, each step shown in FIG. 36 will be described in detail.
(First pass: Dewatering extrusion)
The starting material was dehydrated and extruded by heating the starting material in a kneader cylinder at an inclined temperature of 80° C. (upstream part) to 130° C. (downstream part) and passing it through a biaxial kneader provided with a vent. Although the above set temperature is low as the processing temperature of PLA, PLA was swollen with ε-caprolactam, the mixture of the above starting materials was kneaded, and discharged in an integrated state.

(2nd pass: kneading of ε-caprolactam/PLA swollen material)
The kneaded product after one pass was put into a twin-screw kneader in which the cylinder of the kneader was set to 80° C., and kneading and extrusion were performed. In the second pass, residual water and ε-caprolactam were discharged. The composition ratio of the kneaded product after 2 passes is AcTUKP/MAPP/PLA/talc/(ε caprolactam+water)/AO=(2.13+10)/10/20/5/17.77/1 (total composition mass part is 65.9 )Met.

(Third pass: Dilute extrusion with HDPE)
HDPE is mixed with the above-mentioned kneaded product after 2 passes to obtain a mixture having a composition ratio of (2 pass mixture)/HDPE=65.9/52.87, and this is melt-kneaded with a twin-screw kneader with a cylinder temperature of 180° C. In order to remove ε-caprolactam, degassing was performed with a vacuum vent. The composition ratio of the obtained melt-kneaded product was HDPE/MAPP/PLA/AcTUKP/talc/AO=52.87/10/20/(2.13+10)/5/1.

  A sample for microscopic observation was prepared from the obtained composition according to the above conditions, and the state of fibers in the sample was observed by the above polarizing microscope and electron microscope. The obtained polarization microscope observation image and electron microscope observation image are shown in FIG. According to the polarization microscope image, the fiber diameter of the thick fiber was about 5 to 10 μm, and according to the electron microscope image, the fiber diameter of the thin fiber was about several tens nm to 1 μm.

  A test piece (molded body) was produced from the composition of Example 14 under the conditions described above, and the test piece was subjected to a three-point bending test by the method described above. The results are shown in Table 18.

  By comparison between FIG. 34 and FIG. 37, the fibers in the composition of Example 14 had a clearly improved defibration property as compared with the fibers in the composition of Example 12 in which PLA was not used.

  Regarding the physical properties of the molded body, from the results of Tables 15 and 18, the bending properties of the molded body of Example 14 (containing PLA) are dramatically higher than those of the molded body of Example 12 (containing no PLA). Improved.

Disentanglement test Fiber disentanglement tests were performed using N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), acetone, and isopropyl alcohol (IPA) as organic solvents. Specifically, 30 mg of AcTUKP (Lot No. (16)NT-353) in terms of dry weight produced in Production Example 2 was added to 2 ml of each of the above organic solvents and stirred at room temperature with a magnetic stirrer (500 rpm) for 20 hours. did. After stirring, observe with a polarizing microscope (Olympus system polarizing microscope BX53-31P-OC-1 using a 10x objective lens), and among the number of fibers (A) with a width of 1 to 200 μm, fibers with a width of 1 to 10 μm The number (B) was counted.

The ratio (%) of B to A is determined, and this ratio is called the defibration degree in this test. Then, it was determined that an organic solvent showing a defibration degree of 80% or more had good performance as a defibration aid, and an organic solvent of less than 80% had insufficient performance as a defibration aid.
The results are shown in Table 19.

Claims (17)

A part of the hydrogen atoms of the hydroxyl group of the cellulosic fiber has the general formula (A): Ra-CO- (wherein Ra has an alkyl group having 1 to 4 carbon atoms or an electron donating substituent). Or a general formula (B): Rb- (in the formula, Rb is an alkyl group having 1 to 4 carbon atoms, 2-hydroxyethyl group, 2-hydroxypropyl). Group, a 2-cyanoethyl group or an allyl group), which is a defibration aid for defibrating a hydrophobized cellulosic fiber assembly substituted with an alkyl group which may have a substituent. hand,
The following general formula (1):
^{R 1 -CO-N (R 2} ) -R 3 (1)
(In the formula, R ¹ and R ³ are the same or different and each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R ¹ and R ³ are taken together to form a group having 3 to 11 carbon atoms. An alkylene group, wherein R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an acyl group having 2 to 4 carbon atoms) as a main component. ..   The amide compound is N,N-dimethylacetamide, N,N-dimethylformamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, δ-valerolactam, N-methyl-δ-valerolactam, ε-caprolactam, N. The defibration aid according to claim 1, which is at least one selected from the group consisting of -methyl-ε-caprolactam, N-acetyl-ε-caprolactam, undecanelactam and laurolactam.   The amide compound is selected from the group consisting of N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam, undecanelactam and laurolactam. The defibration aid according to claim 1, which is at least one kind.   The defibration according to claim 1, wherein the amide compound is at least one selected from the group consisting of N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and ε-caprolactam. Auxiliary agent.   The defibration aid is at least selected from the group consisting of talc, clay, zeolite, aluminum oxide, calcium carbonate, titanium oxide, silica, magnesium oxide, mica, lithium chloride, N-methylmorpholine N-oxide and urea. The defibration aid according to any one of claims 1 to 4, comprising a defibration auxiliary agent.   In the defibration aid, hydrogen atoms of a part of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (wherein Ra is an alkyl group having 1 to 4 carbon atoms, or an electron-donating group). A phenyl group which may have a substituent is shown.) A defibration aid for defibrating a hydrophobized cellulosic fiber assembly substituted with an acyl group represented by: The defibration aid according to any one of the above.   The defibration aid is a defibration aid for defibrating a hydrophobized cellulosic fiber assembly in which some hydrogen atoms of the hydroxyl groups of the cellulosic fiber are substituted with an acyl group having 2 to 5 carbon atoms. The defibration aid according to any one of claims 1 to 5.   The defibration aid is a defibration aid for defibrating a hydrophobized cellulosic fiber aggregate in which some of the hydrogen atoms of the hydroxyl groups of the cellulosic fiber are substituted with acetyl groups, The defibration aid according to any one of 5.   The defibration aid according to any one of claims 1 to 8, wherein the hydrophobized cellulosic fiber assembly defibrated by the defibration aid is a plant-derived cellulosic fiber assembly.   The defibration aid according to any one of claims 1 to 9, wherein the hydrophobized cellulosic fiber aggregate defibrated by the defibration aid is a plant-derived lignocellulose fiber aggregate. (1) By using the defibration aid according to any one of claims 1 to 10, hydrogen atoms of a part of the hydroxyl groups of the cellulosic fiber are represented by the general formula (A): Ra-CO- (in the formula, Ra represents an alkyl group having 1 to 4 carbon atoms, or a phenyl group which may have an electron donating substituent.), or an acyl group represented by the general formula (B): Rb-(formula). Rb represents an alkyl group having 1 to 4 carbon atoms, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-cyanoethyl group or an allyl group, and may have a substituent. The first step of defibrating the hydrophobized cellulosic fiber aggregate substituted with, to produce a microfibrillated hydrophobized cellulosic fiber,
(2) including a second step of mixing the microfibrillated hydrophobized cellulosic fibers obtained in the first step with a resin,
A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber and a resin. The defibration aid according to any one of claims 1 to 10, wherein a part of the hydrogen atoms of the hydroxyl groups of the cellulosic fiber is represented by the general formula (A): Ra-CO- (wherein Ra is a carbon number of 1 to 4). Represents an alkyl group or a phenyl group which may have an electron donating substituent), or an acyl group represented by the general formula (B): Rb- (in the formula, Rb has 1 carbon atom). ~4 alkyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2-cyanoethyl group or allyl group), which is substituted with an alkyl group which may have a substituent. A step of mixing a fiber-based fiber assembly and a resin, and defibrating the hydrophobized cellulose-based fiber assembly according to any one of claims 1 to 10 during the mixing operation to form microfibrils,
A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber and a resin. (1) The defibration aid according to any one of claims 1 to 10, wherein a part of the hydrogen atoms of the hydroxyl groups of the cellulosic fiber is represented by the general formula (A): Ra-CO- (wherein Ra is the carbon number. An alkyl group of 1 to 4 or a phenyl group which may have an electron-donating substituent, or an acyl group represented by the general formula (B): Rb- (wherein Rb is A C1-C4 alkyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-cyanoethyl group or an allyl group), which may have a substituent and is substituted with an alkyl group. Hydrophobic cellulosic fiber aggregates, and a resin are mixed, a first step of fibrillating the hydrophobized cellulosic fiber aggregates during the mixing operation to form microfibrils,
(2) a second step of removing the defibration aid from the mixture of the defibration aid, the microfibrillated hydrophobized cellulosic fibers and the resin obtained in the first step,
A method for producing a resin composition containing a microfibrillated hydrophobized cellulosic fiber and a resin.   The microfibrillated hydrophobized cellulosic fiber, resin and phase which are further mixed with a compatibilizing agent in the first step or second step of claim 11, the step of claim 12 or the first step of claim 13. A method for producing a resin composition containing a solubilizer.   The method for producing a resin composition according to claim 11, wherein the resin is one kind or two or more kinds of thermoplastic resins.   The thermoplastic resin is polyamide, polyolefin, aliphatic polyester, aromatic polyester, polyacetal, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate-ABS alloy (PC-ABS alloy) and modified polyphenylene. The method for producing a resin composition according to claim 15, which is one kind or two or more kinds selected from the group consisting of ether (m-PPE).   A molded article made of the resin composition produced by the production method according to claim 11.

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