JP2020075950A - Fiber-reinforced resin composition, production method thereof and molded body - Google Patents

Abstract

To provide a fiber-reinforced resin composition not only excellent in strength and elastic modulus but also excellent in impact-resistant strength.SOLUTION: The fiber-reinforced resin composition contains (A) a microfibrillated cellulose fiber, (B) a vegetable fiber and (C) a thermoplastic resin. In the fiber-reinforced resin composition, (A) the microfibrillated cellulose fiber is a microfibrillated fiber of a fiber composed of a non-chemically modified or chemically modified cellulosic polymer (requirement (a)); and the vegetable fiber (B) is a non-chemically modified vegetable fiber or a chemically modified vegetable fiber (requirement (b)).SELECTED DRAWING: None

Description

  The present invention relates to a fiber reinforced resin composition, a method for producing the same, and a molded product.

  In order to maintain or improve the global environment, there is a demand for the development of a material that has excellent mechanical properties and functionality and that has less impact on humans and the environment during manufacture, use and disposal.

  The fiber-reinforced resin composition has a smaller energy load during manufacturing than metal and is lightweight, and thus has been used in a wide range of fields such as automobile members, aircraft members, household equipment members, and construction members (for example, Patent Documents 1 to 7).

  Patent Document 1 discloses a board in which a composite obtained by impregnating a mat of plant bast fibers such as ramie, kenaf and jute with a resin and a base material are heated and compressed.

  Patent Document 2 discloses a method of repeatedly modifying a mechanical property of a plant fiber by repeatedly applying a tensile load to a twisted yarn of a plant bast fiber such as ramie, and a resin of the plant fiber thus modified. It is disclosed that intermediate materials such as wires, pellets, and thin plates can be prepared through processes such as impregnation, mixing, and hot pressing.

  Patent Documents 3 to 5 disclose composites composed of a mixture of two different types of fibers and a resin (resin adhesive). Specifically, Patent Document 3 discloses a board made of a mixture of plant bast fibers and wood-derived fibers and an adhesive. Patent Document 4 discloses a board in which a mixture of a plant fiber having an average fiber diameter of 70 to 400 μm (main constituent fiber) and a finer plant fiber having an average fiber diameter of 20 to 70 μm is bonded with a granular adhesive, Document 5 discloses the manufacturing method thereof.

  Patent Document 6 contains a nonwoven fabric composed of a cellulose fiber having a nano-order fiber width (number average fiber width of 2 nm or more and less than 1000 nm) and a thicker second fiber (number average fiber width of 1000 nm or more and 100000 nm or less) and a resin. A complex is disclosed.

  Patent Document 7 discloses a fiber reinforced resin composition having improved strength characteristics (elastic modulus and strength) by combining a chemically modified cellulose nanofiber and a thermoplastic resin, and a method for producing the same.

JP, 2010-30092, A JP, 2007-51405, A JP, 2013-256029, A JP, 2014-76589, A JP, 2014-76588, A JP, 2005-25033, A JP, 2016-176052, A

  The resin composition containing the cellulosic microfibrillated fiber is excellent as a structural material because it has higher strength and elastic modulus than a resin containing no fiber, but when the amount of the contained fiber is increased, the impact resistance becomes higher. Since it tends to decrease, there is room for improvement.

  In Patent Document 1, the test results of impact resistance of a board produced by heating and compressing a plant bast fiber mat impregnated with a resin such as ramie and a base material are described together with other test results. However, it does not describe or suggest the impact resistance of the plant bast fiber kneaded with the thermoplastic resin. Patent Document 2 discloses a resin composition containing ramie, and Patent Documents 3 to 6 describe composites composed of a mixture of two kinds of different fibers and a resin (resin adhesive). However, there is no description about impact resistance of these composites. Patent Document 7 discloses a resin composition reinforced with chemically modified cellulose nanofibers derived from wood, but does not contain a plant fiber as used in the present invention.

  The main object of the present invention is to provide a fiber-reinforced resin composition which is excellent in strength and elastic modulus, and is also excellent in impact strength. Another object of the present invention is to provide a manufacturing method and a molded body thereof.

  The present inventors prepared a fiber-reinforced resin composition by using a specific cellulosic microfibrillated fiber and a specific plant fiber in combination, and a molded article made of the composition has excellent strength characteristics (high bending Strength and elastic modulus), and further has excellent characteristics that the impact resistance is improved or the impact resistance is less deteriorated (impact resistance can be maintained) as compared with a resin molded product containing no fiber. Based on the findings, they have completed the present invention.

  The present invention relates to the following fiber-reinforced resin composition, molded article, and method for producing a fiber-reinforced resin composition.

Item 1.
A fiber-reinforced resin composition containing (A) microfibrillated cellulosic fibers, (B) plant fibers, and (C) a thermoplastic resin,
A fiber-reinforced resin composition in which the (A) microfibrillated cellulosic fiber and the (B) plant fiber satisfy the following requirements (a) and (b), respectively.
Requirement (a):
(A) The microfibrillated cellulosic fiber has the following formula (1):
(Lg) Cell-OR (1)
[In the formula (1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin constituting cellulose, holocellulose and / or lignocellulose in the cellulosic polymer.
-OR represents a hydroxyl group in the cellulose and holocellulose and / or lignocellulosic polysaccharides and lignin in the cellulosic polymer, or a hydrogen atom of a part of the hydroxyl group is substituted with a substituent R. R represents a hydrogen atom, an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a microfibrillated fiber of a fiber composed of a non-chemically modified or chemically modified cellulosic polymer represented by.
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.

Item 2.
R in the formula (1) of the requirement (a) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The fiber-reinforced resin composition according to item 1, which is a carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.

Item 3.
Item 3. The fiber-reinforced resin composition according to Item 1 or 2, wherein R in the formula (1) of the requirement (a) is an acetyl group.

Item 4.
The requirement (b) (B) vegetable fiber is (B-1) one or more vegetable fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton. The fiber-reinforced resin composition according to any one of Items 1 to 3 above.

Item 5.
The requirement (b) (B) vegetable fiber is (B-2) a part of hydrogen atoms of the hydroxyl groups of the cellulose constituting the (B-1) vegetable fiber is an acyl group having 2 to 4 carbon atoms. Item 4. The fiber-reinforced resin composition according to any one of Items 1 to 3, which is one or more chemically modified plant fibers that have been modified.

Item 6.
Item 5. The fiber-reinforced resin composition according to any one of Items 1 to 3, wherein the (B) vegetable fiber of the requirement (b) is a ramie and / or a ramie modified with an acetyl group.

Item 7.
The thermoplastic resin (C) is polyamide, polyolefin, aliphatic polyester, aromatic polyester, polyacetal, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate-ABS alloy (PC-ABS alloy). And a modified polyphenylene ether (m-PPE), which is at least one resin selected from the group consisting of the above, and the fiber-reinforced resin composition according to any one of Items 1 to 6.

Item 8.
A molded product comprising the fiber-reinforced resin composition according to any one of items 1 to 7.

Item 9.
A method for producing a fiber-reinforced resin composition containing (A-1) a chemically modified microfibrillated cellulosic fiber, (B) a plant fiber, and (C) a thermoplastic resin,
(AP) chemically modified cellulosic pulp, (B) vegetable fiber, and (C) thermoplastic resin is melt-kneaded, and the step of microfibrillating the chemically modified cellulosic pulp during the melt-kneading,
The (AP) chemically modified cellulosic pulp, the (B) plant fiber, and the (A-1) chemically modified microfibrillated cellulosic fiber have the following requirements (ap), (b), and (a-1), respectively. ), The manufacturing method.
Requirements (ap):
(AP) Chemically modified cellulosic pulp has the following formula (1-1):
(Lg) Cell-OR (1-1)
[In the formula (1-1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin that constitute cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer. -OR indicates that some of the hydrogen atoms of the hydroxyl groups in the polysaccharide and lignin constituting the cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer are replaced by the substituent R, and R is , An acyl group having 2 to 4 carbon atoms, the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a chemically modified cellulosic pulp composed of a chemically modified cellulosic polymer.
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.
Requirement (a-1):
The (A-1) chemically modified microfibrillated cellulosic fiber is a microfibrillated fiber composed of the chemically modified cellulosic polymer represented by the formula (1-1).

Item 10.
A method for producing a fiber-reinforced resin composition containing (A-1) a chemically modified microfibrillated cellulosic fiber, (B) a plant fiber, and (C) a thermoplastic resin,
Process (1):
(AP) a chemically modified cellulosic pulp and (C) a thermoplastic resin are kneaded to microfibrillize the chemically modified cellulosic pulp during the melt-kneading, and step (2):
Including the step of compounding the kneaded product obtained in the step (1), and (B) plant fiber, or a resin composition containing a plant fiber and a thermoplastic resin,
The (AP) chemically modified cellulosic pulp, the (B) plant fiber, and the (A-1) chemically modified microfibrillated cellulosic fiber have the following requirements (ap), (b), and (a-1), respectively. ), The manufacturing method.
Requirements (ap):
(AP) Chemically modified cellulosic pulp has the following formula (1-1):
(Lg) Cell-OR (1-1)
[In the formula (1-1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin that constitute cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer. -OR indicates that some of the hydrogen atoms of the hydroxyl groups in the polysaccharide and lignin constituting the cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer are replaced by the substituent R, and R is , An acyl group having 2 to 4 carbon atoms, the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a chemically modified cellulosic pulp composed of a chemically modified cellulosic polymer.
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.
Requirement (a-1):
The (A-1) chemically modified microfibrillated cellulosic fiber is a microfibrillated fiber composed of the chemically modified cellulosic polymer represented by the formula (1-1).

  Since the fiber-reinforced resin composition of the present invention contains a specific microfibrillated cellulosic fiber, and a specific plant fiber, a molded article comprising this fiber-reinforced resin composition is a molded article of a resin containing no fiber. Compared with, the strength characteristics (elastic modulus and strength) are significantly improved, the impact resistance is also improved, or the impact resistance of the resin itself is maintained.

  That is, by including both the fibrillated cellulosic fiber and the plant fiber in the resin composition, the molded article composed of the fiber reinforced resin composition, the bending elastic modulus and bending strength is improved, the impact resistance is maintained. Alternatively, the effect of improvement can be obtained.

  Since the fiber-reinforced resin composition of the present invention can be molded by the injection molding method, the productivity of molded products is high. Therefore, the molded body can be manufactured at a low manufacturing cost.

  Further, as a method for producing the fiber-reinforced resin composition of the present invention, if a step of melt-kneading a chemically modified cellulosic fiber, a plant fiber, and a resin is adopted, melt kneading and microfibrillation of the chemically modified cellulosic fiber are performed. Since they can be performed simultaneously, the resin composition can be produced with high productivity.

It is an electron micrograph image of acetylated Todo pine pulp. 2 is an electron micrograph image of acetylated Todomatsu fibers in a sample prepared from the composition of Example 2.

(1) Fiber Reinforced Resin Composition The fiber reinforced resin composition of the present invention contains (A) microfibrillated cellulosic fibers, (B) plant fibers, and (C) thermoplastic resin. The (A) microfibrillated cellulosic fiber satisfies the following requirement (a).

Requirement (a):
(A) The microfibrillated cellulosic fiber has the following formula (1):
(Lg) Cell-OR (1)
[In the formula (1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin constituting cellulose, holocellulose and / or lignocellulose in the cellulosic polymer.
-OR represents a hydroxyl group in the cellulose and holocellulose and / or lignocellulosic polysaccharides and lignin in the cellulosic polymer, or a hydrogen atom of a part of the hydroxyl group is substituted with a substituent R. R represents a hydrogen atom, an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a microfibrillated fiber of a fiber composed of a non-chemically modified or chemically modified cellulosic polymer represented by.

The (B) vegetable fiber satisfies the following requirement (b).
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.

(1-1) (A) Microfibrillated cellulosic fiber The terms used in the present specification have the following meanings.

  "Microfibrillated cellulosic fiber" means a cellulosic fiber that has been microfibrillated. Hereinafter, the "microfibrillated cellulosic fiber" may be referred to as "MFC".

  The “cellulosic fiber” means a fiber composed of at least one polymer (cellulosic polymer) selected from the group (polymer group) consisting of cellulose, holocellulose, and lignocellulose. Hereinafter, the cellulosic polymer may be referred to as “(Lg) Cell-OH”. That is, in the present specification, the cellulosic fiber means a fiber composed of a cellulosic polymer “(Lg) Cell-OH”.

  Here, “(Lg) Cell −” means a residue obtained by removing a hydroxyl group from a lignin and a polysaccharide constituting at least one kind of polymer selected from the above-mentioned polymer group.

  The cellulosic fiber used in the present invention is a fiber composed of a cellulosic polymer [(Lg) Cell-OH], or a polysaccharide constituting cellulose, holocellulose and / or lignocellulose in the cellulosic polymer. And a fiber composed of a polymer in which hydrogen atoms of some hydroxyl groups in lignin are substituted with a substituent R (the details of the substituent R will be described later).

That is, the cellulosic fiber used in the present invention has the following formula (1): (Lg) Cell-OR (1)
[In the formula (1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin constituting cellulose, holocellulose and / or lignocellulose in the cellulosic polymer.
OR represents a hydroxyl group in the cellulose and holocellulose and / or lignocellulosic polysaccharide and lignin in the cellulosic polymer, or a part of the hydrogen atoms of the hydroxyl group is substituted with a substituent R. Indicates. ]
A fiber composed of a non-chemically modified cellulose-based polymer (hereinafter, also referred to as “non-chemically modified cellulose-based fiber”) or a fiber composed of a chemically-modified cellulose-based polymer (hereinafter, “chemically modified cellulose”). It is also defined as "system fiber").

Therefore, the microfibrillated cellulosic fiber (MFC) used in the present invention is
(i) a non-chemically modified cellulosic fiber [a fiber composed of a polymer in which OR is a hydroxyl group in the above formula (1)] is microfibrillated (that is, a non-chemically modified MFC), and
(ii) Chemically modified cellulosic fiber [OR in the above formula (1) is replaced by hydrogen atoms of some hydroxyl groups in the polysaccharide and lignin constituting cellulose, holocellulose and / or lignocellulose in the cellulosic polymer. Fibers composed of cellulosic polymers substituted with groups R] include microfibrillated fibers (ie chemically modified MFCs).

  The chemically modified MFC is also a fiber in which hydrogen atoms of some hydroxyl groups of the polysaccharide and lignin in the cellulose, holocellulose and / or lignocellulose constituting the non-chemically modified MFC are replaced by the substituent R.

  Chemically modified MFC is a method of chemically modifying cellulosic pulp (hereinafter also referred to as “CP”) to form a chemically modified CP, and fibrillating the obtained chemically modified CP to form microfibrils, or It can be obtained by a method of chemically modifying MFC.

  Here, the "cellulosic pulp" means a fiber assembly composed of a cellulosic polymer. Cellulosic pulp (CP) includes lignin-free pulp (cellulose-based pulp, holocellulose-based pulp, etc.) and lignin-containing pulp (ligno pulp).

  The method for producing the chemically modified MFC will be described later.

Substituent (R)
The MFC contained in the fiber reinforced resin composition of the present invention is a non-chemically modified MFC or a chemically modified MFC. From the viewpoint of dispersibility in the resin and defibration, the MFC is preferably a chemically modified MFC.

  Among the chemically modified MFCs, the substituent R in the above formula (1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same as above.) One or two kinds selected from the group consisting of a carboxy group-containing acyl group and a salt of the carboxy group-containing acyl group. Chemically modified MFCs are preferred.

  The substituent R in the formula (1) is more preferably an acyl group having 2 to 3 carbon atoms (acetyl group and propionyl group). As the substituent R, an acetyl group is most preferable from the viewpoint of ease of production and production cost.

  The salt of the carboxyl group-containing acyl group represented by the formula (2) means that the carboxy group is in the state of an inorganic salt or an organic salt.

  As the inorganic salt, alkali metal salts such as sodium salt, lithium salt and potassium salt; divalent metal salts such as calcium salt, barium salt, zinc salt and copper salt; trivalent metal salts such as aluminum salt are preferable. .. As the organic salt, a primary to quaternary ammonium salt and a salt with a polyamine are preferable.

  The above chemically modified MFC having various substituents is preferable because it has good dispersibility in the fiber reinforced resin composition.

  The non-chemically modified MFC and the chemically modified MFC may be combined (combined) and contained in the fiber-reinforced resin composition of the present invention. Further, two kinds of chemically modified MFCs different from each other may be combined (used together) and contained in the fiber-reinforced resin composition of the present invention.

  By using two kinds of chemically modified MFCs having different substituents R in combination, these chemically modified MFCs can be favorably dispersed in the fiber reinforced resin composition.

Raw material for chemically modified MFC and non-chemically modified MFC As a raw material for the chemically modified MFC and the non-chemically modified MFC, pulp is preferably used.

  Pulp is obtained by separating fibers contained in plant materials such as wood, bamboo, hemp, jute, kenaf, cotton, beet, rice straw, bagasse, beet marc, cellulose, hemicellulose, holocellulose and And / or contains lignocellulose.

  As wood, for example, pine (Todo pine, red pine, ezo nut, etc.), Douglas fir, hemlock spruce, sitka spruce, cedar, cypress and other coniferous trees, or eucalyptus, acacia, poplar, beech, oak, oak, alder, etc. Hardwood-derived wood is preferably used. Agricultural waste products, waste paper, knitted fabrics, etc. may be used as the plant raw materials other than the above. The used paper is preferably deinked used paper, corrugated used paper, magazines and used copy paper. The pulp raw material is not limited to these. One type of pulp may be used alone, or two or more types selected from these may be used.

  As pulp, which is a raw material of non-chemically modified MFC and chemically modified MFC, both cellulosic pulp (CP), that is, pulp containing no lignin and pulp containing lignin (pulp containing lignocellulose) can be used. it can. Hereinafter, "pulp containing lignocellulose" may be referred to as "ligno pulp" or "LP".

  Ligno pulp (LP) is preferably used for the pulp that is a raw material of the non-chemically modified MFC and the chemically modified MFC. That is, it is preferable that (Lg) Cell- in the formula (1) of the requirement (a) is a residue obtained by removing a hydroxyl group from the polysaccharide and lignin constituting lignocellulose.

  Lignocellulose is a complex hydrocarbon polymer (natural polymer mixture) that constitutes the cell wall of trees. It is known that lignocellulose is mainly composed of polysaccharide cellulose, hemicellulose, and lignin which is an aromatic polymer (see Reference Example 1 and Reference Example 2 below).

Reference Example 1: Review Article Conversion of Lignocellulosic Biomass to Nanocellulose: Structure and Chemical Process HV Lee, SBA Hamid, and SK Zain, Scientific World Journal Volume 2014 ,, Article ID 631013, 20 pages, http://dx.doi.org /10.1155/2014/631013
Reference Example 2: New lignocellulose pretreatments using cellulose solvents: A review, Noppadon Sathitsuksanoh, Anthe George and YH Percival Zhang, J Chem Technol Biotechnol 2013; 88: 169-180

  As used herein, the term "lignocellulose" means a lignocellulose having the chemical structure naturally present in plants, an artificially modified lignocellulose, or a mixture thereof. This is a lignocellulose having a naturally occurring chemical structure contained in various pulps obtained by mechanically and / or chemically treating plants, for example, wood, chemically or mechanically modified lignocellulose. Cellulose or a mixture thereof.

  The lignocellulosic fibers used in the present invention are not limited to those of naturally occurring lignocellulosic chemical structures. Moreover, the lignin content in the lignocellulose is not limited. Therefore, "lignocellulose" means a substance in which lignin and cellulose are present in a plant, and / or a mixture of lignin and cellulose, regardless of the lignin content. Therefore, the terms "lignocellulose" and "ligno pulp" are to be construed as lignocellulose and lignopulp, respectively, even if the content of lignin component is very small.

  Pulp or lignopulp can be obtained by treating the above-mentioned plant-derived raw material by a mechanical pulping method, a chemical pulping method, or a combination of a mechanical pulping method and a chemical pulping method.

  As such pulp, various kraft pulps (softwood unbleached kraft pulp (NUKP), softwood oxygen bleached kraft pulp (NOKP), and softwood bleached kraft pulp (NBKP)) are preferable. Mechanical pulp (MP) such as groundwood pulp (GP), refiner GP (RGP), thermomechanical pulp (TMP) and chemithermomechanical pulp (CTMP) is also preferable.

  Some kraft pulp does not contain lignin, but regardless of its content, it can be used as a raw material for non-chemically modified MFC and chemically modified MFC.

  Among these, lignopulp, compared to cellulose fiber or pulp that does not contain lignin, that the number of manufacturing steps is small, that the yield from the raw material (for example, wood) is good, there are few chemical agents required for its production. In addition, since it can be manufactured with less energy, it is advantageous in terms of manufacturing cost. Therefore, lignopulp can be advantageously used in the present invention.

  Furthermore, among softwood pulps, Ligno pulp obtained from Todo pine, Japanese red pine, or cedar is a fiber having excellent strength characteristics by containing a non-chemically modified MFC and / or a chemically modified MFC produced by using the same. It is preferable because a reinforced resin composition can be obtained.

  The amount of lignin contained in lignocellulose and ligno pulp can be quantified by the Klarson method. In the present invention, it is preferable to use lignopulp containing lignin in an amount of about 0.1 to 40% by mass. The lignin content of the ligno pulp is more preferably about 0.1 to 35% by mass, and particularly preferably about 0.1 to 30% by mass.

Method for producing non-chemically modified MFC Non-chemically modified MFC, for example, a suspension or slurry of non-chemically modified CP, refiner, high pressure homogenizer, grinder, single-screw or multi-screw kneader (preferably twin-screw kneader), bead mill It can be prepared by defibrating and microfibrillating the non-chemically modified CP using a known means such as mechanical grinding or beating by the above.

Method for producing chemically modified MFC The chemically modified MFC can be obtained by chemically modifying a cellulosic pulp (CP) to obtain a chemically modified cellulosic pulp (chemically modified CP) and defibrating it.

  The chemically modified MFC can also be obtained by defibrating cellulosic pulp (CP) to obtain microfibrillated cellulosic fiber (MFC) and chemically modifying this.

  First, a method for producing a chemically modified cellulosic pulp (chemically modified CP) used for preparing a chemically modified MFC will be described. A method for defibrating cellulosic pulp (CP) or chemically modified CP will be described later.

Method for producing chemically modified cellulosic pulp (chemically modified CP)
(i) Production of acylated cellulosic pulp (acylated CP having 2 to 4 carbon atoms) Formula (1): (Lg) Among chemically modified pulps composed of the chemically modified cellulosic polymer represented by Cell-OR, Pulp composed of chemically modified cellulosic polymers in which the substituent R is an acyl group having 2 to 4 carbon atoms (acylated CP) is a material that does not contain hydroxyl groups present on the fiber surface or in the amorphous part of the cellulosic pulp (CP) as a raw material. Obtained by acylation.

  This acylation acylates hydroxyl groups such as cellulose, hemicellulose, and lignin hydroxyl groups present on the fiber surface or the amorphous portion of the raw material CP so as not to destroy the cellulose crystal structure originally present in the raw material CP. Preferably.

  The acylation reaction involves suspending the raw material CP in an anhydrous aprotic polar solvent capable of swelling the raw material CP, such as N-methylpyrrolidone, N, N-dimethylformamide, etc., and having a corresponding acyl group. It can be carried out by a conventional method (method described in JP 2016-176052 A) using a carboxylic acid anhydride or an acid chloride in the presence of a base.

  The method of measuring the degree of substitution with R in Formula (1) (described in detail below) can be according to a conventional method (method described in JP 2016-176052 A). The degree of substitution can be adjusted by adjusting the amount of the acylating agent in the above-mentioned acylation, the reaction temperature, the reaction time and the like.

(ii) Production of Cellulose Pulp Modified with Carboxy Group-Containing Acyl Group (abbreviated as Carboxyacylated CP) and salt thereof Formula (1): (Lg) Cell-OR, R is the following formula (2): :

(In the formula (2), R ¹ and R ² are the same as above.)
The carboxy group-containing acylated cellulose pulp represented by (carboxyacylated CP) is a conventional method (method described in Patent No. 5496435 etc.), in which the raw material CP has the following formula (3):

(In the formula (3), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an alkenyl group or an alkyl group having 3 to 20 carbon atoms which may have a branched chain. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
By reacting succinic anhydride represented by or a derivative thereof (hereinafter, these may be referred to as “anhydride of formula (3)”), a part of the hydroxyl groups present in the CP of the raw material is converted into an acyl group. It can be produced by subjecting the compound to half-esterification (half-esterification with a carboxyl group-containing acyl group represented by the above formula (2)).

  The chemical modification (half-esterification) of the raw material CP with the acid anhydride of the formula (3) is carried out by mixing the raw material CP dispersed in an aprotic polar organic solvent and the acid anhydride of the formula (3) in the presence of a base. It can be carried out by heating and reacting to partially esterify the hydroxyl groups present in the raw material CP.

  Here, the half ester means that one of the two carbonyl groups present in the acid anhydride of formula (3) forms an ester bond with the hydroxyl group in the raw material CP, and the other carbonyl group is a hydroxycarbonyl group. It means the ester in the finished state.

  The carboxyl group present in the carboxyacylated CP represented by the formula (2) may be in the state of an inorganic salt or an organic salt. Such a salt of carboxyacylated CP is obtained by dispersing the carboxyacylated CP in a liquid such as water or a hydroalcohol, and a hydroxide of an alkali metal such as sodium, lithium or potassium, a hydrogen carbonate, Carbonates; divalent metal salts such as calcium salts, barium salts, zinc salts, copper salts; trivalent metal salts such as aluminum salts; aqueous solutions or dispersions of primary to quaternary ammonium salts and salts with polyamines. Can be prepared by adding.

  Examples of the alkenylsuccinic anhydride belonging to the acid anhydride of the formula (3) include compounds having a skeleton derived from an olefin having 4 to 20 carbon atoms and a maleic anhydride skeleton.

  As these compounds, pentenyl succinic anhydride, hexenyl succinic anhydride, octenyl succinic anhydride, decenyl succinic anhydride, undecenyl succinic anhydride, dodecenyl succinic anhydride, tridecenyl succinic anhydride, hexadecane Alkenyl succinic anhydrides such as cenylsuccinic anhydride and octadecenyl succinic anhydride can be preferably used.

  As the alkenylsuccinic anhydride, each compound may be used alone, or two or more kinds may be used in combination.

  In the present specification, an alkenyl succinic anhydride having an olefin chain having a specific carbon number may be represented by a combination of the abbreviation (ASA) of the alkenyl succinic anhydride and the carbon number of the olefin chain.

  For example, an alkenyl succinic anhydride (hexadecenyl succinic anhydride) having an olefin chain having 16 carbon atoms may be referred to as “ASA-C16”. Further, the ASA used in the present invention may be described by a product name or a product code number. For example, AS1533 (manufactured by Seikou PMC Co., Ltd.), TNS135 (manufactured by Seikou PMC Co., Ltd.), RIKACID DDSA (tetrapropenyl succinic anhydride, manufactured by Shin Nihon Rikagaku Co., Ltd.) and the like can be preferably used.

  Examples of the alkyl succinic anhydride include those obtained by reducing the unsaturated bond of the alkenyl group of the alkenyl succinic anhydride represented by the above formula (3) by hydrogenation (that is, succinic acid in which the alkenyl group is converted to an alkyl group). Acid anhydrides) can be used.

  As these compounds, alkyl succinic anhydrides such as octyl succinic anhydride, dodecyl succinic anhydride, hexadecyl succinic anhydride and octadecyl succinic anhydride can be preferably used.

  As the alkylsuccinic anhydride, each compound may be used alone, or two or more kinds may be used in combination. Further, the alkyl succinic anhydride and the alkenyl succinic anhydride can be used together.

  The reaction between the raw material CP and the acid anhydride of the formula (3) is preferably carried out in an anhydrous aprotic polar solvent (organic solvent) in the presence of a base in order to accelerate the reaction. As the base, amines such as pyridine and dimethylaniline, alkali metal salts of acetic acid such as potassium acetate and sodium acetate, and carbonate salts of alkali metals such as lithium carbonate, potassium carbonate and sodium carbonate can be preferably used.

  The reaction temperature depends on the boiling point of the solvent used, but is preferably about 20 to 150 ° C, more preferably about 30 to 120 ° C, and further preferably about 40 to 100 ° C.

  The reaction time is appropriately adjusted depending on the type of acid anhydride of formula (3). The degree of half-esterification was determined by collecting a part of the lignocellulosic fiber during the reaction, measuring its infrared (IR) absorption spectrum, and tracing the IR absorption peak based on the carbonyl stretching vibration of the half-ester produced by the reaction. Adjustment can be performed while checking (substitution degree).

  In addition, when chemically modifying microfibrillated cellulose (MFC) to produce a chemically modified MFC, MFC is used in place of the cellulosic pulp (CP), and the same as (i) and (ii) above. A chemically modified MFC can be obtained by chemically modifying MFC by the method.

Degree of Modification of Chemically Modified CP or Chemically Modified MFC with Substituent R The degree of modification of chemically modified CP or chemically modified MFC with a substituent R (hereinafter, also referred to as “degree of substitution” or “DS”) refers to the above formula (1 ) The degree to which the hydrogen atom of the hydroxyl group present in one unit (repeating unit) of the residue [(Lg) Cell-] of the chemically modified cellulosic polymer is substituted with the substituent R.

  When the chemically modified cellulosic polymer is composed entirely of cellulose (in the case of cellulose), this repeating unit is a glucopyranose residue, and the number of hydroxyl groups per unit is 3, so the upper limit of the degree of substitution is Is 3.

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

  Therefore, the upper limit of the degree of substitution with the substituent R in the 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 lignopulp.

  Also, when the cellulosic polymer is holocellulose, since the holocellulose contains hemicellulose together with cellulose, the average number of hydroxyl groups in this repeating unit is smaller than 3. Therefore, the upper limit of the degree of substitution is smaller than 3.

  Although depending on the content of hemicellulose or lignin in the cellulosic fiber as described above, substitution of the chemically modified cellulosic pulp (chemically modified CP) and the chemically modified microfibrillated cellulosic fiber (chemically modified MFC) with the substituent R The degree (DS) is preferably about 0.3 to 2.55. By setting the substitution degree (DS) to about 0.3 to 2.55, a chemically modified MFC having an appropriate crystallinity and SP (solubility parameter) can be obtained.

  When the substituent R is an acyl group having 2 to 4 carbon atoms, the substitution degree (DS) is more preferably about 0.4 to 2.55, further preferably 0.5 to 2.5. When the substituent R is an acetyl group, DS is preferably 0.4 to 2.5, more preferably 0.5 to 2.5, and further preferably 0.56 to 2.5. If the DS is within that range, the crystallinity can be maintained at about 42.7% or more.

  When the substituent R is a carboxy group-containing acyl group represented by the above formula (2), the degree of substitution (DS, that is, the degree of half-esterification) is higher than that of a highly hydrophilic raw material CP fiber that is more hydrophobic than that. From the necessity of being uniformly dispersed in the thermoplastic resin, it is preferably about 0.05 to 2.0, more preferably about 0.1 to 2.0, still more preferably about 0.1 to 0.8.

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

Method for producing chemically modified MFC by defibrating chemically modified CP For defibration and microfibrillation of chemically modified CP, for example, the chemically modified CP is made into a suspension or slurry, and refiner, high pressure homogenizer, grinder, uniaxial or multi-axis It can be carried out by using a known means such as mechanical milling or beating with a shaft kneader (preferably a multi-axis kneader) or a bead mill.

  When preparing a fiber-reinforced resin composition using the chemically modified CP, the chemically modified CP is a uniaxial or multiaxial kneading machine (preferably a multiaxial kneading machine) together with a thermoplastic resin, which is melted and kneaded under heating. Is preferred. The chemically modified CP can be fibrillated by the shearing force during kneading to form microfibrils, and can be chemically modified MFC in the thermoplastic resin. Therefore, according to the method of melt-kneading the chemically modified CP with the thermoplastic resin, the thermoplastic resin composition containing the chemically modified MFC can be advantageously produced by a simple operation.

Method for producing chemically modified MFC from non-chemically modified MFC As described above, the raw material cellulosic pulp (raw material CP) is made into a suspension or slurry, and refiner, high pressure homogenizer, grinder, uniaxial or multiaxial kneader (preferably a twin A non-chemically modified MFC can be produced by defibration and fibrillation using a known means such as mechanical milling or beating with a shaft kneader) or a bead mill.

  Then, this can be chemically modified by a method similar to the method for producing the chemically modified CP to produce a chemically modified MFC.

Non chemically modified MFC and chemical modification MFC fiber diameter non-chemically modified MFC, which has loosened the fibers in the aforementioned cellulosic pulp (e.g. Rigunoparupu) to nanosize level (the defibrated), chemically modified MFC is The fibers in the above-mentioned chemically modified cellulosic pulp (for example, chemically modified ligno pulp) are disentangled (disentangled) to a nano size level.

  The average fiber diameter (fiber width) of the non-chemically modified MFC and the chemically modified MFC contained in the fiber reinforced resin composition is usually about 4 to 1000 nm, preferably about 4 to 800 nm, more preferably about 4 to 200 nm. The average fiber length is preferably about 5 μm or more.

  By incorporating a chemically modified MFC having an average fiber diameter in the above range into a resin, a fiber reinforced resin composition having excellent strength properties can be produced.

  When a fiber-reinforced resin composition is produced using the chemically modified CP, the chemically modified CP can be melt-kneaded with a thermoplastic resin, and the chemically modified CP can be defibrated into the chemically modified MFC simultaneously with the kneading. ..

  At this time, the defibration of the chemically modified CP is insufficient, and even if the fiber composition after defibration contains a chemically modified MFC larger than the fiber diameter in the resin composition, the object of the present invention is achieved. As long as it is included in the present invention, a resin composition containing such a chemically modified MFC.

  For example, as long as the flexural modulus of the chemically modified MFC-containing resin composition shows a flexural modulus of 1.1 times or more with respect to the flexural modulus of a resin containing no cellulosic fibers, this is the chemically modified MFC-containing resin of the present invention. It is a composition.

  When the chemically modified MFC is prepared using the non-chemically modified MFC, preferable ranges of the average fiber diameter and the average fiber length of the non-chemically modified MFC are the same as those of the above chemically modified MFC.

  The fiber diameter and fiber length of non-chemically modified MFC and chemically modified MFC can be measured using a scanning electron microscope (SEM). The average value of the fiber diameter (average fiber diameter) and the average value of the fiber length (average fiber length) are obtained as an average value when measured for at least 30 MFCs or chemically modified MFCs in the field of view of a scanning electron microscope. be able to.

The specific surface area of the non-chemically modified MFC and chemical modification MFC specific surface area non-chemically modified MFC and chemical modification MFC is preferably about 70~300m ² / g, more preferably about 70~250m ² / g, 100~200m ² / About g is more preferable. By increasing the specific surface area of non-chemically modified MFC and chemically modified MFC, the contact area can be increased when the composition is combined with a resin (matrix), thereby improving the strength of the resin molded body. be able to. The chemically modified MFC is preferable because it can be easily dispersed in the resin of the resin composition and can improve the strength of the resin molded body.

Crystallinity of Non-Chemically Modified MFC and Chemically Modified MFC The non-chemically modified MFC and the chemically modified MFC are preferably in a state where the crystal structure of cellulose existing in the raw material pulp is maintained as much as possible.

  In the chemically modified MFC, it is preferable that the hydroxyl groups existing on the surface of the raw material fibers, such as the hydroxyl groups of cellulose and the hemicellulose, are chemically modified so that the cellulose crystal structure originally present in the raw material pulp is not broken.

  By such a chemical modification treatment, it is possible to obtain a chemically modified MFC having excellent mechanical properties inherent in MFC. By chemically modifying the MFC, the dispersibility of the chemically modified MFC in the resin is promoted, and the reinforcing effect of the chemically modified MFC on the resin is improved.

  In the fiber-reinforced resin composition of the present invention, it is preferable that the non-chemically modified MFC and the chemically modified MFC contained in the composition have a crystallinity of about 42.7% or more and the crystal form thereof is a cellulose type I crystal. The “crystallinity” is an abundance ratio of crystals (mainly cellulose type I crystals) in all cellulose. The crystallinity of the non-chemically modified MFC and the chemically modified MFC (preferably cellulose I type crystals) is preferably about 50% or more, more preferably about 55% or more, further preferably about 55.6% or more, about 60% or more. Is even more preferable, and about 69.5% or more is particularly preferable.

  The upper limit of the crystallinity of non-chemically modified MFC and chemically modified MFC is about 80%.

  The cellulose type I crystal structure is, for example, as described in "Dictionary of Cellulose", New Edition, First Edition, pages 81-86, or pages 93-99, published by Asakura Shoten. Most natural celluloses have a cellulose type I crystal structure. On the other hand, a cellulose fiber having, for example, a cellulose II, III, or IV structure rather than a cellulose I crystal structure is derived from cellulose having a cellulose I crystal structure. The I-type crystal structure has a higher crystal elastic modulus than other structures.

  The fact that the chemically modified MFC has the I-type crystal structure is typical in two positions near 2θ = 14 to 17 ° and 2θ = 22 to 23 ° in the diffraction profile obtained by the wide-angle X-ray diffraction image measurement. It can be determined from having a peak.

  From the X-ray diffraction and the like, it is estimated that the ratio of crystalline regions in cellulose is about 50 to 60% in wood pulp and that in bacterial cellulose is higher than this, about 70%. Cellulose not only has a high elastic modulus due to its extended chain crystal, but also exhibits a strength five times that of steel and a linear thermal expansion coefficient of 1/50 or less that of glass.

(1-2) (B) Plant fiber The plant fiber (B) contained in the fiber-reinforced resin composition of the present invention satisfies the requirement (b) described above.

That is, (B) vegetable fiber,
(B-1) Lamy, hemp, linen, jute, abaca, sisal, kenaf, and one or more plant fibers selected from the group consisting of cotton (hereinafter, also referred to as "non-chemical modified plant fiber"), Or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same as above.)
The one or more chemically modified plant fibers modified with a carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.

  Here, Lamy is also known as “ramie”, hemp is also known as “cannabis”, linen is also known as “flax”, jute is also known as “burlap”, Abaca is also known as “manila hemp”, and sisal is also known as “sisal”. Kenaf is also referred to as "Hemp".

  Among the above plant fibers, ramie, hemp, linen, jude, and kenaf are bast fibers, abaca and sisal are vein fibers, and cotton is seed hair fibers.

  The average fiber diameter of the plant fibers is preferably about 10 to 70 μm. The average fiber length of plant fibers is preferably about 2 to 200 mm.

  The non-chemically modified plant fiber is preferably one or more plant fibers selected from the group consisting of ramie, linen, abaca, and kenaf.

  Among these, one or two kinds of plant fibers selected from the group consisting of ramie and linen are more preferable, and ramie is most preferable.

  The chemically modified plant fibers include ramie, hemp, linen, jute, abaca, sisal, kenaf, and some hydrogen atoms of the hydroxyl groups of cellulose constituting the plant fibers selected from the group consisting of cotton, having 2 to 4 carbon atoms. The one or more chemically modified plant fibers modified with the acyl group of 1 are preferable because they are easily produced.

  Among these, ramie, linen, abaca, and some hydrogen atoms of the hydroxyl groups of cellulose constituting the plant fiber selected from the group consisting of kenaf, 1 or 2 modified with an acyl group having 2 to 4 carbon atoms. More than one kind of chemically modified plant fiber is preferred, some hydrogen atoms of the hydroxyl group of cellulose constituting the ramie, more preferably chemically modified plant fiber modified with an acyl group having 2 to 4 carbon atoms, cellulose constituting the ramie Most preferably is a chemically modified plant fiber in which a part of hydrogen atoms of the hydroxyl groups of is modified with acetyl groups.

  Among plant fiber fibers including non-chemically modified plant fibers or chemically modified plant fibers, ramie or acetylated ramie suitably contributes to improvement or maintenance of impact resistance of the molded article of the fiber-reinforced resin composition of the present invention. Therefore, it is particularly preferable.

Degree of modification of chemically modified plant fiber The degree of modification of chemically modified plant fiber (hereinafter also referred to as “degree of substitution” or “DS”) consists of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton. Part of the hydrogen atoms of the hydroxyl group of cellulose constituting the plant fiber selected from the group, an acyl group having 2 to 4 carbon atoms, a carboxy group-containing acyl group represented by the formula (2), or the carboxy group-containing The degree of modification with a salt of an acyl group.

  Since the plant fiber has a high content of cellulose, the upper limit of the substitution degree is theoretically close to 3, but the preferable substitution degree (DS) is about 0.05 to 1.5, more preferably about 0.1 to 1.2.

  By setting such a substitution degree, it is possible to improve the affinity with the resin without impairing the original crystallinity of the cellulose in the plant fiber.

  When the substituent is an acyl group having 2 to 4 carbon atoms, the substitution degree (DS) is more preferably about 0.2 to 1.2, further preferably 0.3 to 1.0. When the substituent is an acetyl group, the preferred DS is 0.3 to 1.2, more preferably 0.3 to 0.7.

  Chemically modified plant fiber is obtained by using plant fiber instead of cellulose pulp (CP), and acylating or half-esterifying the plant fiber according to the method for producing chemically modified cellulose pulp (chemically modified CP) described above. It can be manufactured.

(1-3) (C) Thermoplastic resin As a matrix used in the fiber-reinforced resin composition of the present invention, thermoplastic resins among various resins are preferably used because of their excellent productivity and versatility. ..

  As the thermoplastic resin, 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) is mentioned.

  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), a copolymer of polyethylene (PE) and polypropylene (PP), maleic anhydride modified polypropylene (MAPP), polyethylene (PE, especially high density polyethylene HDPE), etc. 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.

  Since a blended product of polycarbonate (PC) and ABS (PC-ABS alloy) is excellent in impact resistance, weather resistance and moldability, it is preferably used as the matrix of the fiber reinforced resin composition of the present invention.

  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.

  Among thermoplastic resins, PA, POM, PP, MAPP, PE, polylactic acid, lactic acid copolymer resin, PBS, PET, PPT, PBT, from the viewpoint of excellent mechanical properties, heat resistance, surface smoothness and appearance. It is preferable to use at least one resin selected from the group consisting of PS, ABS resin and PC-ABS alloy.

  Further, resins other than the above, for example, polyvinyl chloride, polyvinylidene chloride, fluororesin, (meth) acrylic resin, (thermoplastic) polyurethane, vinyl ether resin, polysulfone resin, cellulose resin (eg triacetylated cellulose, (Diacetylated cellulose, etc.) can also be preferably used.

(2) Content ratio of components (A), (B), and (C) in the fiber-reinforced resin composition The content ratio of (A) MFC in the fiber-reinforced resin composition of the present invention is (C) thermoplastic resin. It is preferably about 2 to 50 parts by mass, more preferably about 2 to 40 parts by mass, and even more preferably about 3 to 35 parts by mass with respect to 100 parts by mass. The content ratio of (A) MFC in the fiber reinforced resin composition is most preferably about 5 to 30 parts by mass with respect to 100 parts by mass of the (C) thermoplastic resin.

  The content ratio of the (B) plant fiber in the fiber-reinforced resin composition of the present invention is preferably about 1 to 40 parts by mass, more preferably about 2 to 30 parts by mass, relative to 100 parts by mass of the (C) thermoplastic resin. It is preferably about 2.5 to 25 parts by mass, more preferably about 2.5 parts by mass. The content ratio of (B) vegetable fiber (preferably ramie or acetylated ramie) in the fiber reinforced resin composition is most preferably about 3 to 15 parts by mass relative to 100 parts by mass of (C) thermoplastic resin. preferable.

  The ratio of (A) MFC to (B) vegetable fiber in the fiber-reinforced resin composition of the present invention, that is, (A) MFC content / (B) vegetable fiber content (A / B) is a mass ratio. Is preferably 0.2 to 4, more preferably 0.5 to 3, and even more preferably 0.5 to 2.

  By blending (A) MFC with (C) thermoplastic resin, a fiber-reinforced resin composition having excellent mechanical properties, heat resistance, surface smoothness and appearance can be obtained.

  By blending the (B) vegetable fiber with the (A) MFC in the (C) thermoplastic resin, a lightweight fiber-reinforced resin composition having excellent mechanical properties can be obtained. Also, by blending (B) vegetable fiber with (A) MFC in (C) thermoplastic resin, the impact resistance of the composite (molded body) produced is improved or maintained, and the strength and elastic modulus are improved. Can be improved. In particular, by blending the ramie fiber and / or the chemically modified ramie fiber together with the chemically modified MFC into the thermoplastic resin, not only the elastic modulus and strength of the composite (molded article) but also impact resistance can be improved.

  The fiber-reinforced resin composition of the present invention, even if containing (A) MFC, and (B) vegetable fiber, as well as general-purpose plastic, because it is softened and easily molded when heated, good moldability Can be expressed.

  In the fiber-reinforced resin composition of the present invention, in addition to (A) MFC, (B) vegetable fiber, and (C) thermoplastic resin, for example, a compatibilizer; a surfactant; an antioxidant; a flame retardant; Inorganic compounds such as tannin, zeolite, ceramics, metal powder; colorants; plasticizers; fragrances; pigments; flow control agents; leveling agents; conductive agents; antistatic agents; UV absorbers; UV dispersants; deodorants, etc. You may mix | blend an additive arbitrarily.

  The content of the above-mentioned additive can be appropriately adjusted within the range where the effect of the present invention is not impaired.

  When the fiber-reinforced resin composition of the present invention contains (A-1) chemically modified MFC as (A) MFC, self-aggregation of these fibers by hydrogen bond can be suppressed. Therefore, when (A-1) chemically modified MFC, (B) vegetable fiber, and (C) thermoplastic resin are mixed, (A-1) aggregation of chemically modified MFCs is suppressed, and (A-1) chemical The modified MFC and the (B) vegetable fiber show good dispersibility in the (C) thermoplastic resin. As a result, the fiber-reinforced resin composition of the present invention is excellent in mechanical properties, heat resistance, surface smoothness and appearance.

  In a fiber-reinforced resin composition containing (A-1) chemically modified MFC as (A) MFC, the solubility parameter (SP) of (A-1) chemically modified MFC is closer to that of (C) thermoplastic resin. Is preferred.

  (C) When a highly polar resin is used as the thermoplastic resin, (A) MFC, when the substituent R is, for example, an acetyl group, its substitution degree (DS) is about 0.4 to 1.2 and its solubility is It is preferred to use acetylated MFCs with parameters around 12-15. As the highly polar resin, for example, PA, POM, polylactic acid and the like are preferable.

  (C) When using a resin having a small polarity as the thermoplastic resin, (A) MFC having a substitution degree (DS) of about 1.2 or more and a solubility parameter of about 8 to 12 is used. Preferably. As the resin having a small polarity, for example, PP, PE and the like are preferable. As the chemically modified MFC, an acetylated MFC having a substitution degree (DS) of about 1.2 or more is preferable.

(3) Method for producing fiber-reinforced resin composition
Manufacturing method 1
The fiber-reinforced resin composition of the present invention comprises (A) MFC, (B) plant fiber, and (C) thermoplastic resin (matrix material) melt-kneaded to obtain (A) MFC and (B) plant fiber ( C) It can be produced by dispersing it in a thermoplastic resin.

Manufacturing method 2
When the (A) MFC is a chemically modified MFC, the fiber-reinforced resin composition of the present invention contains a chemically modified cellulosic pulp (chemically modified CP), (B) plant fiber, and (C) a thermoplastic resin at once. Then, it is preferable to melt-knead and manufacture using a kneader or the like. In this case, it is possible to combine the chemically modified CP with the chemically modified MFC while defibrating it during melt-kneading. Therefore, prepare the chemically modified MFC separately, and use the (B) plant fiber and (C) thermoplastic It can be produced more easily than the method of producing a fiber-reinforced resin composition by kneading with a resin.

Therefore, the manufacturing method 2 is a manufacturing method using (AP) chemically modified CP as a raw material when (A) MFC is a chemically modified MFC. This production method is specifically a method for producing a fiber-reinforced resin composition containing (A-1) chemically modified microfibrillated cellulosic fibers, (B) plant fibers, and (C) thermoplastic resin. hand,
The method includes a step of melt-kneading (AP) the chemically modified cellulosic pulp, (B) plant fiber, and (C) a thermoplastic resin, and micro-fibrillating the chemically modified cellulosic pulp during the melt-kneading.

And this manufacturing method, the (AP) chemically modified cellulosic pulp, the (B) plant fiber, and the (A-1) chemically modified microfibrillated cellulosic fiber, the following requirements (ap), (b ) And (a-1) are satisfied.
Requirements (ap):
(AP) Chemically modified cellulosic pulp has the following formula (1-1):
(Lg) Cell-OR (1-1)
[In the formula (1-1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin that constitute cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer. -OR indicates that some of the hydrogen atoms of the hydroxyl groups in the polysaccharide and lignin constituting the cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer are replaced by the substituent R, and R is , An acyl group having 2 to 4 carbon atoms, the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a chemically modified cellulosic pulp composed of a chemically modified cellulosic polymer.

Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.

Requirement (a-1):
The (A-1) chemically modified microfibrillated cellulosic fiber is a microfibrillated fiber composed of the chemically modified cellulosic polymer represented by the formula (1-1).

  In the production method 2, the fibrillation of the chemically modified CP proceeds well due to the shear stress during the kneading. During the kneading, the chemically modified CP is well defibrated in the resin into the (A) chemically modified MFC. According to the production method 2, it is possible to produce a fiber-reinforced resin composition in which (A) the chemically modified MFC and (B) vegetable fiber are favorably dispersed in the (C) thermoplastic resin.

Manufacturing method 3
The fiber-reinforced resin composition of the present invention, when (A) MFC is a chemically modified MFC, (AP) chemically modified CP and (C) a thermoplastic resin are kneaded to chemically modify the chemically modified CP during melt kneading. A kneaded product is obtained by defibration into a modified MFC, and then the obtained kneaded product and (B) a vegetable fiber or a resin composition containing a vegetable fiber and a thermoplastic resin can be produced by a method of melt kneading. it can.

Therefore, the production method 3 is another production method using (AP) chemically modified CP as a raw material when (A) MFC is a chemically modified MFC. This method is a method in which, after melt-kneading the chemically modified CP and the thermoplastic resin together, the kneaded material is melt-kneaded by adding the resin composition containing the plant fiber or the plant fiber and the thermoplastic resin. is there. Specifically, this method is a method for producing a fiber-reinforced resin composition containing (A-1) chemically modified microfibrillated cellulosic fiber, (B) plant fiber, and (C) thermoplastic resin. hand,
Process (1):
(AP) a chemically modified cellulosic pulp and (C) a thermoplastic resin are kneaded to microfibrillize the chemically modified cellulosic pulp during the melt-kneading, and step (2):
A production method comprising a step of compounding the kneaded product obtained in the step (1) with (B) vegetable fiber or a resin composition containing a vegetable fiber and a thermoplastic resin.

And this manufacturing method, the (AP) chemically modified cellulosic pulp, the (B) plant fiber, and the (A-1) chemically modified microfibrillated cellulosic fiber, the following requirements (ap), (b ) And (a-1) are satisfied.
Requirements (ap):
(AP) Chemically modified cellulosic pulp has the following formula (1-1):
(Lg) Cell-OR (1-1)
[In the formula (1-1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin that constitute cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer. -OR indicates that some of the hydrogen atoms of the hydroxyl groups in the polysaccharide and lignin constituting the cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer are replaced by the substituent R, and R is , An acyl group having 2 to 4 carbon atoms, the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a chemically modified cellulosic pulp composed of a chemically modified cellulosic polymer.

Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):

(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.

Requirement (a-1):
The (A-1) chemically modified microfibrillated cellulosic fiber is a microfibrillated fiber composed of the chemically modified cellulosic polymer represented by the formula (1-1).

  In the production method 3, the fibrillation of the chemically modified CP proceeds well due to the shear stress during the kneading. During the kneading, the chemically modified CP is well defibrated in the resin into the (A-1) chemically modified MFC. According to the production method 3, it is possible to produce a fiber-reinforced resin composition in which (A-1) chemically modified MFC and (B) vegetable fiber are favorably dispersed in the (C) thermoplastic resin. Further, according to the production method 3, it is possible to produce a fiber-reinforced composition having better impact resistance than the production method 2.

  As a resin composition containing plant fiber and a thermoplastic resin used in the production method 3, (I) (a) a melt mixture of a plant fiber and (b) a thermoplastic resin, and (II) (a) a plant fiber (B) Both the powder mixture with the thermoplastic resin can be used.

  The heating set temperature at the time of melt kneading in each manufacturing method is a temperature (A + 20) higher than the recommended processing temperature (A + 20) from the minimum processing temperature (A ° C) recommended by the supplier that supplies the thermoplastic resin used in the present invention. C.) range is preferred.

  When PA6 is used as the (C) thermoplastic resin, the set temperature for heating during melt kneading is preferably 225 to 240 ° C. When POM is used, the heating set temperature during melt kneading is preferably 170 ° C to 190 ° C. When using PP and MAPP, the heating set temperature during melt kneading is preferably 160 to 180 ° C.

  By setting the mixing temperature in this temperature range, it is possible to uniformly mix (A) the chemically modified MFC or the chemically modified CP, (B) the plant fiber and (C) the thermoplastic resin.

  In Manufacturing Method 2 and Manufacturing Method 3 among the above manufacturing methods, the fibrillation is performed by the shear stress of the kneader while the chemically modified CP that has not been defibrated is mixed with the resin, so that the manufacturing cost can be reduced.

(4) Molded product of fiber reinforced resin composition The molded product of the present invention comprises a fiber reinforced resin composition.

  A molded product can be produced using the fiber-reinforced resin composition of the present invention.

  From the fiber-reinforced resin composition of the present invention, if necessary, a molding material having a shape such as a film shape, a sheet shape, a plate shape, a pellet shape, and a powder shape is prepared, and this molding material is used for manufacturing a molded body be able to.

  The fiber-reinforced resin composition or the molding material of the present invention can be molded by various known molding methods to produce molded products having various shapes such as a plate shape, a rod shape, and a three-dimensional structure. Examples of the molding method include a mold molding method, an injection molding method, an extrusion molding method, a hollow molding method, and a foam molding method. Among these, the injection molding method is excellent in productivity and manufacturing cost because the molding speed is high and molding of a complicated shape is easy.

  Since the molded article of the present invention is molded from a fiber reinforced resin composition containing (A) MFC, (B) plant fiber, and (C) thermoplastic resin, a fiber containing a fiber having a large specific gravity such as glass fiber. It is lighter than a molded product molded from the reinforced resin composition. In addition, thermal recycling is easier than that of a molded product molded from a fiber-reinforced resin composition containing an inorganic fiber such as glass fiber or carbon fiber. Further, the molded product of the present invention is advantageous in reducing carbon dioxide emissions in LCCO2 (life cycle CO2).

  By using the molded article of the present invention as an interior material, an exterior material, a structural material of a transportation machine such as an automobile, an electric train, a ship, an airplane, etc., it is possible to achieve improvement of energy efficiency of a transportation machine and reduction of exhaust gas. it can.

  By using the molded product of the present invention for a housing, a structural material, an internal part, etc. of an electric appliance such as a personal computer, a television, a telephone, etc., it is possible to reduce the weight thereof. By reducing the weight, it is possible to reduce energy consumption during transportation of the electric appliances, and it is possible to comfortably use the electric appliances.

  By using the molded product of the present invention as a building material, it becomes possible to improve the earthquake resistance of the building.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples (reference examples). The present invention is not limited to these examples.

  In the examples, the content of various components such as cellulosic pulp, chemically modified cellulosic pulp, unmodified MFC, chemically modified MFC, plant fiber, chemically modified plant fiber, and thermoplastic resin is% by mass unless otherwise specified. indicate.

  Then, in the present specification, the content ratio of the cellulosic fibers in the composition is represented by the mass ratio of the fiber component (cellulose + hemicellulose) in the total mass of the composition. That is, the content rate of the chemically modified cellulosic fiber in the composition is indicated by the content rate (percentage) of the mass converted into the non-chemically modified fiber.

  Regarding a resin composition (or a molded product thereof) containing a chemically modified cellulosic fiber and a chemically modified plant fiber, (a) the indication of the type of resin and its content (percentage), (b) the type of chemically modified fiber (abbreviation) The method of combining and displaying the content of () and the content (percentage) of the unmodified fiber is illustrated below.

  For example, (i) Polyamide 6 (PA6) and its content percentage (a), (ii) Chemically modified Todomatsu fiber (Ac Todomatsu) and its unmodified Todomatsu equivalent percentage (b), (iii) Chemically modified ramie (Ac Ramie) and its unmodified Lamy equivalent content percentage (c), PA6, Ac Todomatsu, and the composition containing Ac Lamy, is described as "PA6 / Ac Todomatsu / Ac Lamy = a / b / c (However, a + b + c = 100).

I. Test Method The test method used in Examples and Comparative Examples is as follows.

(1) Lignin quantification method (Klarson method)
The glass fiber filter paper (GA55) was dried in a 110 ° C. oven to a constant weight, allowed to cool in a desiccator, and then weighed. A sample (about 0.2 g) absolutely dried at 110 ° C. was precisely weighed and put in a 50 mL tube.

  72% concentrated sulfuric acid (3 mL) was added, and while appropriately crushing the contents with a glass rod, the tube was placed in warm water at 30 ° C. and kept warm for 1 hour. Next, the tube contents and 84 g of distilled water were poured into an Erlenmeyer flask and mixed, and then reacted in an autoclave at 120 ° C. for 1 hour.

  After allowing to cool, the content was filtered through a glass fiber filter paper to collect insoluble matter by filtration, and washed with 200 mL of distilled water. It was dried in a 110 ° C. oven to a constant weight and weighed.

(2) Cellulose and hemicellulose quantification method (sugar analysis)
The glass fiber filter paper (GA55) was dried in an oven at 110 ° C. to a constant weight, allowed to cool in a desiccator, and then weighed. A sample (about 0.2 g) absolutely dried at 110 ° C. was precisely weighed and put in a 50 mL tube.

  72% concentrated sulfuric acid (3 mL) was added, and while appropriately crushing the contents with a glass rod, the tube was placed in warm water at 30 ° C. and kept warm for 1 hour. Next, the tube contents and 84 g of distilled water were added and quantitatively poured into an Erlenmeyer flask and mixed, then 1.0 mL of the mixture was put into a pressure resistance test tube, and 100 μL of 0.2% inositol solution was added as an internal standard.

  72% concentrated sulfuric acid (7.5 μL) was added using a measuring pipette and reacted in an autoclave at 120 ° C. for 1 hour.

  After allowing to cool, 100 μL of the reaction solution was diluted with ultrapure water and subjected to ion chromatography analysis manufactured by Thermo Fisher Scientific Co., Ltd. to analyze sugar components contained in the sample.

(3) Measuring method of chemical modification degree (DS) of cellulose or hemicellulose hydroxyl groups
(3-1) Back Titration Method The DS measurement method of a sample in which the hydroxyl groups of cellulose, hemicellulose, and lignocellulose are acylated (esterified) will be described below by taking an acetylated sample as an example. The same applies to other acylations.

Preparation, weighing and hydrolyzed samples were dried and 0.5 g (A) was accurately weighed. Ethanol 75mL and 0.5N NaOH 50mL (0.025mol) (B) are added there, and it agitates for 3 to 4 hours.

  This was filtered, washed with water, and dried, and FT-IR measurement of the sample on the filter paper was performed to confirm that the absorption peak based on the carbonyl of the ester bond disappeared, that is, the ester bond was hydrolyzed. .. This filtrate was used for the back titration described below.

The back titration filtrate contains sodium acetate resulting from hydrolysis and NaOH added in excess. The neutralization titration of this NaOH was carried out using 1N HCl and phenolphthalein, and the number of moles of the acetyl group ester-bonded to the hydroxyl group of cellulose and the like from the following formula (C), and the number of moles of repeating units of cellulose Calculate (D).
0.025mol (B)-(number of moles of HCl used for neutralization) = number of moles of acetyl groups ester-bonded to the hydroxyl groups of cellulose (C)
(Molecular weight of cellulose repeating unit 162 × number of moles of cellulose repeating unit (unknown (D))) + (molecular weight of acetyl group 43 × (C)) = 0.5 g of sample weighed (A)

The DS is calculated by the following formula from the obtained (C) and (D).
DS = (C) / (D)

(3-2) Method of measuring DS by infrared (IR) absorption spectrum DS of esterified cellulose / lignocellulose can also be determined by measuring infrared (IR) absorption spectrum.

When cellulose / lignocellulose is esterified, a strong absorption band derived from ester carbonyl (C = O) appears near 1733 cm ^-1. Therefore, the intensity (area) of this absorption band is plotted on the horizontal axis and the above-mentioned back titration is performed. First, create a calibration curve by plotting the DS value obtained by the method on the horizontal axis.

  Then, the intensity of the absorption band of the sample is measured, and the DS value of the sample is obtained from this value and the calibration curve. According to this method, DS can be measured quickly and easily.

(4) Strength test method
A three-point bending test was carried out using a universal testing machine (Autograph AG5000E, manufactured by Shimadzu Corporation). The test conditions were a bending speed of 10 mm / min and a fulcrum distance of 64 mm.

(5) Izod Impact Test An Izod impact test was performed using an Izod impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.). A notch having a depth of 2 mm was inserted in the center of the test piece. In the 2.75JN test, the notch side was hit with a 2.75J hammer to propagate a crack from the notch, and the impact strength was calculated.

(6) Microscopic observation of fibers (observation of fiber length and fiber diameter)
The fiber sample was observed with a field emission scanning electron microscope (FE-SEM) and JSM-7800F manufactured by JEOL. The measurement conditions were an acceleration voltage of 1.5 kV and a magnification of 200 to 5000 times.

The sample preparation method is as follows.
1) Preparation of fiber sample before kneading with resin
1-1) The sample was placed in a glass vial containing ethanol and ultrasonically stirred to suspend the fiber in ethanol.
1-2) A small amount of an ethanol suspension of fibers was dropped on a copper plate, and ethanol was evaporated at room temperature.
1-3) The sample was platinum-coated using a sputtering device (JEOL SEC-3000FC Auto Fine Coater).
2) Preparation of fiber sample contained in resin composition For microscope observation, taking CNF in the molded product of nylon 6 (PA6) composition (PA6 / CNF = 90/10) containing cellulose nanofiber (CNF) as an example A method for preparing a sample will be described.
2-1) A test piece of 4x2x1.2 mm was cut out from the injection molded product.
2-2) The test piece was added to 400 ml of NMP and immersed at 190 ° C for 2 to 4 hours to elute PA6.
2-3) The residue (fiber) after elution of PA6 was put in a glass vial containing ethanol, and ultrasonically stirred to suspend the fiber in ethanol. After that, a sample for microscopic observation was prepared according to 1-2) and 1-3) above.

II. Material used
A. Raw material pulp
(1) Todomatsu derived kraft pulp (Todomatsu P)
Nippon Paper Papyria Co., Ltd.'s unbleached kraft pulp derived from Todomatsu (hereinafter referred to as Todomatsu P) slurry (water suspension with a pulp slurry concentration of 3% by mass) was applied to a single disc refiner (Aikawa Iron Works Co., Ltd.). The solution was allowed to pass and was repeatedly refined until the Canadian Standard Freeness (CSF) value reached 255 mL, which was then paper-made and dried to obtain sheet-like Todomatsu P with a thickness of about 0.2 mm. Sheet-like Todomatsu P having different dry states (that is, different solid content) was obtained depending on the lot. Those with a solid content of 83.2% are called sheet-like Todomatsu P-1, those with a solid content of 80.5% are called sheet-like Todomatsu P-2, and those with a solid content of 83.86% are called sheet-like Todomatsu P-3. .. As a result of analysis of sugar components, the composition (mass%) was cellulose 84.4%, hemicellulose 14.5%, and lignin 1.1%.

B. Chemically modified pulp
(1) Production of acetylated Todomatsu pulp (Ac Todomatsu P-1, serial number TO39, Acized DS 0.56 ) 2403 g (solid content 83.2%) of the above sheet-like Todomatsu P-1 (solid content 2000 g) and acetic anhydride 6792 g (Purity 93%) was added and heated, and after the temperature of the reaction mixture reached 89 ° C., the reaction was carried out at the same temperature for 6 hours. The reaction mixture was cooled to 50 ° C., the liquid was removed by decantation, and the mixture was heated to about 60 ° C. under reduced pressure to distill off acetic anhydride and acetic acid. It was dried to obtain a sheet-like Ac Todomatsu P-1 weighing about 2200 g. The degree of acetylation of Ac todomatsu P-1 (hereinafter referred to as "Ac-modified DS") was 0.56.

  The degree of acetylation substitution (Ac-modified DS) was calculated by measuring the IR spectrum in accordance with the above-mentioned (3-2) Method of measuring DS by infrared (IR) absorption spectrum. Also, the following Ac-DS of Ac-Todomatsu P-2 and P-3, Ac-ramie, Ac-kenaf, Ac-flax, and Ac-abaca were calculated by the same method.

  This sheet-shaped Ac Todomatsu P-1 was used for preparing the compositions of Example 1 (Test No. PA6-629) and Comparative Example 1 (Test No. PA6-628) below.

(2) Production of acetylated Todomatsu Pulp (Ac Todomatsu P-2, serial number TO23, Acated DS 0.7 ) 2485 g (solid content 80.5%) of the above sheet-like Todomatsu P-2 (solid content 2000 g) and acetic anhydride 6480 g (Purity 93%) was added and heated, and after the temperature of the reaction mixture reached 104 ° C., the reaction was carried out at the same temperature for 6 hours. The reaction mixture was cooled to 50 ° C., the liquid was removed by decantation, the acetic anhydride and acetic acid anhydride were distilled off by heating to about 60 ° C. under reduced pressure, and the sheet was dried to a dry weight of about 2200 g Ac Todomatsu P- 2 (Ac-modified DS 0.7) was obtained.

  This sheet-like Ac Todomatsu P-2 was prepared from the compositions of Example 2 (Test No. PA6-568), Example 3 (Test No. PA6-558), and Comparative Example 2 (Test No. PA6-561) described below. Used for.

(3) Production of acetylated Todomatsu pulp (Ac Todomatsu P-3, production number TO72, Acized DS 0.67) The sheet-like Todomatsu P-3 (solid content 83.86%) 2385 g (solid content 2000 g) and acetic anhydride 4378 g (Purity 93%) was added and heated, and after the temperature of the reaction mixture reached 110 ° C., the reaction was carried out at the same temperature for 6 hours. The reaction mixture was cooled to 50 ° C., the liquid was removed by decantation, the acetic anhydride and acetic acid anhydride were distilled off by heating to about 60 ° C. under reduced pressure, and the sheet was dried to a dry weight of about 2200 g Ac Todomatsu P- 3 (Ac-modified DS 0.67) was obtained.

  This sheet-like Ac Todomatsu P-3 was prepared as Example 4 (Test No. PA6-645), Example 5 (Test No. PA6-642), Example 6 (Test No. PA6-646) and Example 7 (Test). No. PA6-644) and Comparative Example 5 (Test No. PA6-640).

C. As the vegetable fiber (1) ramie, Tosco ramie (trade name 6T TOP fineness 4.63 dtex) was cut into a length of 1 to 3 cm and used.

(2) Acetylated ramie (Ac ramie)
400 ml of acetic anhydride (5 times equivalent of cellulose) and 240 ml of acetic acid were added to 120 g of ramie (water content 8.42%) cut to a length of 1 to 3 cm and reacted at 100 ° C. for 20 hours. After ethanol was added to the reaction mixture to stop the reaction, the reaction mixture (solid content) was collected by filtration. This was washed with water (3 times), washed with isopropyl alcohol (IPA) 3 times, and dried to obtain Ac ramie (Ac-modified DS 0.33).

(3) As kenaf, kenaf (B-grade fiber bundle from Bangladesh, about 20 to 100 μm) purchased from OCM GROUP Co., Ltd. was used.

(4) Acetylated kenaf (Ac kenaf)
The Ac kenaf of Ac-modified DS 0.25 used in Example 9 (Test No. PA6-687) described below was produced as follows. 16 g of acetic anhydride and 288 g of acetic acid were added to 32 g of kenaf fiber, and heated in an oil bath at 100 ° C. for 5 hours. The reaction mixture was collected by filtration, washed with water, and washed with IPA, and the fiber was cut into about 1 to 2 cm and dried.

  The Ac kenaf of Ac-modified DS 0.64 used in Example 10 (Test No. PA6-688) described below was produced as follows. 51 g of acetic anhydride and 243 g of acetic acid were added to 32 g of kenaf fiber, and the mixture was heated in an oil bath at 100 ° C. for 5 hours. The reaction mixture was collected by filtration, washed with water, and washed with IPA, and the fiber was cut into about 1 to 2 cm and dried.

(5) As the linen, flax manufactured by Nippon Paper Papyria Co., Ltd. was used.

(6) Acetylated flax (Ac flax)
Ac flax of Ac-modified DS 0.57 used in each of Example 4 (Test No. PA6-645), Example 5 (Test No. PA6-642), and Comparative Example 6 (Test No. PA6-641) described below was as follows. As manufactured. N-methylpyrrolidone (NMP) was added to flax pulp and dehydrated under reduced pressure with heating. Acetic anhydride (0.7 molar equivalent) and K ₂ CO ₃ (0.2 molar equivalent) were added to this NMP suspension of flax pulp (solid content 15%), and the mixture was heated and stirred at 80 ° C. for 2 hours to cause reaction. After the reaction was completed, the solid matter was washed with acetone and water to obtain a slurry of acetylated flax pulp, which was dehydrated.

(7) The abaca manufactured by Nippon Paper Papyria Co., Ltd. was used as the abaca.

(8) Acetylated abaca (Ac abaca)
The Ac abaca of Ac-modified DS 0.5 used in each of Example 6 (Test No. PA6-646), Example 7 (Test No. PA6-644), and Comparative Example 7 (Test No. PA6-643) described below is as follows. As manufactured. NMP was added to abaca pulp and dehydrated under reduced pressure with heating. Acetic anhydride (0.6 molar equivalent) and K ₂ CO ₃ (0.2 molar equivalent) were added to this NMP suspension of abaca pulp (solid content 15%), and the mixture was heated and stirred at 80 ° C. for 2 hours to cause reaction. After the reaction was completed, the solid matter was washed with acetone and water to obtain a slurry of acetylated abaca pulp, which was dehydrated.

D. Polyamide (powder type, grade: A1020LP) manufactured by Unitika Ltd. was used as the resin (1) powdery polyamide 6 (sometimes referred to as “PA6 powder”).

(2) As the pelletized polyamide 6 (sometimes referred to as “PA6 pellets”), pelletized polyamide 6 (grade: A1020BRL) manufactured by Unitika Ltd. was used.

III. Production of fiber-reinforced resin composition and molded article thereof, and evaluation results (1-1) (A) MFC fibrillated acetylated Todomatsu (fibrillated Ac Todomatsu), (B) plant fiber ramie (no chemical modification) or Fiber-reinforced resin composition containing acetylated ramie (Ac ramie) and (C) PA6 as thermoplastic resin

Example 1 (Test No. PA6-629): Production of PA6 composition containing fibrillated Ac Todomatsu (Ac-compound DS 0.56) and ramie, and molded body thereof Ac sheet Todomatsu P-1 [Ac-compound DS 0.56, Manufacturing number T039, composition ratio (Ac / lignin / cellulose + hemicellulose = 1.47 / 0.11 / 10)] was soaked in distilled water overnight to allow it to swell, and then roughened by a mixer (FM10C: Nippon Coke Industry Co., Ltd.). After crushing, the crushed product was put into distilled water and stirred. Next, water was replaced with IPA, PA6 powder was added and mixed, and the mixture was filtered to obtain a mixture of Ac Todomatsu P-1 and PA6 powder. This was stirred and dried at about 60 ° C. with a stir drier (Trimix TX-5: manufactured by Inoue Seisakusho Co., Ltd.). The composition ratio of the obtained mixture (masterbatch) was Ac Todomatsu / PA6 powder = 11.58 / 21.75 (this is referred to as powdered MB-1).

  PA6 powder and ramie were added to powdered MB-1 to make a mixture of powdered MB-1 / PA6 powder / ramie = 33.3 / 61.67 / 5, which was uniformly mixed in a plastic bag and then a twin-screw melt kneader (Φ15mm , L / D = 45, manufactured by Technovel Co., Ltd.). The melt-kneading set temperature was 200 to 215 ° C. (upstream to downstream of the kneader). The composition of the obtained kneaded product was PA6 / Ac Todomatsu / ramie = 83.42 / 11.58 / 5. The kneaded material was water-cooled and pelletized to obtain pellets of a PA composition containing fibrillated Ac todomatsu (Ac-DSDS 0.56) and ramie (kneaded composition PA6 / Ac todomatsu / ramie = 83.42 / 11.58 / 5). .

Manufacture of molded body The above pellets are put into an injection machine (injection molding machine NPX7, manufactured by Nissei Plastic Industry Co., Ltd.) and injection-molded at a cylinder set temperature of 210 to 235 ° C, and width x length x thickness = 10 x 80 x A 4 mm strip type test piece (molded body) was obtained.

Example 2 (Test No. PA6-568): Production of a PA6 composition containing fibrillated Ac Todomatsu (Ac-compound DS 0.7) and Ac ramie (Ac-compound DS 0.33), and a molded article thereof. The sheet-like Ac Todomatsu P- 2 (Ac-modified DS 0.7, serial number T023, composition ratio (Ac / lignin / (cellulose + hemicellulose) = 1.83 / 0.11 / 10)] was soaked in distilled water overnight and allowed to swell, and then a mixer (FM10C: Japan It was roughly crushed by Coke Industry Co., Ltd., and the crushed product was put in distilled water and stirred.

  Next, the water was replaced with IPA, PA6 powder was added and mixed, and the mixture was filtered to obtain a mixture of Ac Todomatsu P-2 and PA6 powder. This was agitated and dried at about 60 ° C. with the agitator dryer. The composition ratio of the obtained mixture (masterbatch) was Ac Todomatsu / PA6 powder = 11.44 / 32.59 (this is called powdered MB-2).

  Powdered MB-2 with PA6 powder and Ac ramie cut to 1 to 1.5 cm (DS 0.33 of Ac, Ac / ramie composition ratio = 0.94 / 10) was added, and the composition ratio was powdered MB-2 / PA6 powder. A mixture of / Ac ramie = 44.55 / 50 / 5.45 was put in a vinyl bag and uniformly mixed, and then melt-kneaded by the biaxial melt-kneader. The melt-kneading set temperature was 200 to 215 ° C. (upstream to downstream of the kneader). The composition ratio of the obtained kneaded product was PA6 / Ac Todomatsu / Ac ramie = 82.61 / 11.94 / 5.45. The mixture was water cooled, pelletized, dried and injection molded as in Example 1.

  When the composition ratio of the chemically modified fiber in the obtained molded product was converted into the content of the unmodified fiber and displayed, it was PA6 / Ac Todomatsu / Ac ramie = 85/10/5.

Example 3 (Test No. PA6-558): Preparation of PA6 Composition Containing Fibrillated Ac Todomatsu (Ac Derivative DS 0.7) and Ac Ramie (Ac Derivative DS 0.33), and Molded Article Thereof Without passing through the master batch of Todomatsu / PA6 powder (powdered MB-2), create the master batch of Ac Todomatsu / PA6 powder / Ac ramie (powdered MB-3), melt and knead it with PA6, It is a method for producing a PA6 composition containing fibrillated Ac Todomatsu and Ac ramie having the same composition as in Example 2 above. Ac Todomatsu P-2 and Ac ramie were the same as in Example 2.

  The sheet-shaped Ac Todomatsu P-2 was immersed overnight in distilled water to swell it, and then coarsely pulverized by the mixer, and the pulverized product was put in distilled water and stirred. Next, the water was replaced with IPA, PA6 powder and Ac ramie dipped in IPA were added and mixed, and filtered to obtain a mixture of Ac Todomatsu P / PA6 powder / Ac ramie. This was agitated and dried at about 60 ° C. with the agitator dryer. The composition ratio of the obtained powdery MB-3 was Ac Todomatsu P / PA6 powder / Ac ramie 11.94 / 32.59 / 5.47.

  PA6 powder was added to powdered MB-3 to make a mixture of powdered MB-3 / PA6 powder = 50/50, which was uniformly mixed in a plastic bag, then melt-kneaded and pelletized in the same manner as in Example 2. A PA6 composition containing fibrillated Ac Todomatsu and Ac ramie of the same composition as in Example 2 was obtained. Then, this was injection-molded in the same manner as in Example 1 to obtain a molded body.

Comparative Example 1 (Test No. PA6-628): Preparation of a PA6 composition containing fibrillated Ac Todomatsu and its moldings This is the control composition of Example 1. The same sheet-like Ac Todomatsu P-1 (Ac-modified DS 0.56) as in Example 1 was used, and was produced by the following method.

  The sheet-shaped Ac Todomatsu P-1 was immersed overnight in distilled water to swell it, and then coarsely pulverized by the mixer, and the pulverized product was put in distilled water and stirred. Next, the water was replaced with IPA, PA6 powder was added and mixed, and the mixture was filtered. This was agitated and dried by the agitator and dryer at about 60 ° C. to obtain a powdery composition (masterbatch) (composition ratio: Ac Todomatsu / PA6 powder = 11.58 / 21.75, which is called powdery MB-4). ).

  Powdered MB-4 and PA6 powder were mixed (mixing ratio: powdered MB-4 / PA6 powder = 33.3 / 66.7) and uniformly mixed, and then melt-kneaded in the same manner as in Example 1 to obtain PA6. A composition comprising fibrillated Ac Todomatsu (composition ratio: PA6 / Ac Todomatsu = 88.42 / 11.58, unmodified Todomatsu content PA6 / Ac Todomatsu = 90/10 when converted to the composition ratio) was obtained. Then, this was injection-molded in the same manner as described above to obtain a molded body.

Comparative Example 2 (Test No. PA6-561): Preparation of a PA6 composition containing fibrillated Ac Todomatsu and its molded body This is a control composition of Examples 2 and 3. The same sheet-like Ac Todomatsu P-2 (Ac-modified DS 0.7) as in Examples 2 and 3 was used, and was produced by the following method.

  The sheet-shaped Ac Todomatsu P-2 was immersed overnight in distilled water to swell it, and then coarsely pulverized by the mixer, and the pulverized product was put in distilled water and stirred. Next, the water was replaced with IPA, PA6 powder was added and mixed, and the mixture was filtered. This was agitated and dried at about 60 ° C. in the agitator / dryer to obtain a powdery composition (masterbatch) (composition ratio: Ac Todomatsu / PA6 powder = 11.94 / 21.39, referred to as powdery MB-5).

  PA6 powder was added to powder MB-5 to make powder MB-5 / PA6 powder = 33.3 / 66.7, and after uniformly mixing in a plastic bag, melt kneading in the same manner as in Example 3 to prepare PA6 and fibrils. To obtain a kneaded composition (composition ratio: PA6 / Ac Todomatsu = 88.06 / 11.94). Then, this was injection-molded in the same manner as described above to obtain a molded body.

Comparative Example 3 (Test No. PA6-560): Preparation of PA6 Composition Containing Ac Ramie, and Moldings Thereof This is the control composition of Examples 2 and 3. As in Examples 2 and 3, Ac ramie (Ac-modified DS 0.33) cut to 1 to 1.5 cm was used, and was prepared by the following method.

  PA6 powder was added to Ac ramie to form a mixture having a composition ratio of PA6 powder / Ac ramie = 89.06 / 10.94, which was uniformly mixed in a plastic bag, and then melt-kneaded in the same manner as in Example 3 to obtain PA6 and Ac ramie. To obtain a kneaded composition (composition ratio: PA6 powder / Ac ramie = 89.06 / 10.94). Then, this was injection-molded in the same manner as described above to obtain a molded body.

Comparative Example 4 (Test No. PA6): Manufacture of Control Molded Product (PA6 Molded Product) In the same manner as in the manufacture of the molded product of Example 1, PA6 powder was molded by the above injection machine, and width × length × thickness = 10. A strip-shaped test piece (molded body) of × 80 × 4 mm was obtained.

(1-2) Test Results of Molded Body The flexural modulus, bending strength, and impact resistance of the above-mentioned molded body (test piece) were measured by the above-described test methods. The results are shown in Table 1.

  In addition, in the composition content ratio of Table 1, the composition content ratio of the chemically modified fiber (Ac Todomatsu and Ac ramie) is converted into the mass percentage of the corresponding unmodified fiber (Todomatsu and ramie).

  As shown in Table 1 above, a molded body of the PA6 composition of Example 1 containing fibrillated cellulosic fibers modified with acetyl groups (fibrillated Ac Todomatsu) and ramie, and the fiber of Comparative Example 4 were not included. When compared with the PA6 molded body, the flexural modulus, bending strength, and flexural modulus of the molded body of Example 1 were 2.4 times, 1.6 times, and 1.1 times that of the PA6 molded body of Comparative Example 4, respectively. Met.

  In addition, a molded article of the PA6 composition of Example 2 containing fibrillated cellulosic fibers modified with acetyl groups (fibrillated Ac todomatsu) and ramie modified with acetyl groups (Ac ramie), and Comparative Example 4. When compared with a PA6 molded body containing no fiber, the flexural modulus, flexural strength, and flexural modulus of the molded body of Example 2 were 2.6 times, 1.7 times, and 1.7 times that of the PA6 molded body of Comparative Example 4, respectively. It was 1.3 times.

(1-3) Microscopic observation of acetylated Todomatsu pulp before kneading with the resin, and acetylated Todomatsu fiber in the composition Prepare a sample by the above method, acetylated Todomatsu pulp before kneading with the resin, and implementation The acetylated Todomatsu fiber in the composition of Example 2 was microscopically observed using a scanning electron microscope (SEM). As the acetylated Todomatsu pulp, Ac Todomatsu pulp (Production No. T081) having the same degree of acetylation substitution (Acized DS 0.68) as the Ac Todomatsu pulp (Ac-modified DS 0.7) used in Example 2 was used.

  FIG. 1 shows an electron micrograph image of acetylated Todo pine pulp. FIG. 2 shows an electron micrograph image of the acetylated Todomatsu fiber in the sample prepared from the composition of Example 2.

  From FIG. 1, it is understood that the shape of Todomatsu pulp is maintained. The diameter of the fibers was about 20 μm for thin fibers and about 60 μm for thick fibers. The fiber length was over 1900 μm.

  In the low-magnification (X200) SEM photograph on the left side of Fig. 2, a thick fiber with a diameter of about 10 µm or less and a length of about 300 µm was observed. This is because of the proportion of the fibers in Todomatsu's fiber. Not ramie fiber. The fibers observed in the high-magnification (X5000) SEM photograph on the right have a thick fiber with a diameter of 1 μm and a thin fiber with a length of tens of nanometers. It was more than μm.

  From the above, it was found that fibrillation of pulp progressed due to the complexation with PA6 (melt kneading), and acetylated Todomatsu pulp with a diameter of several tens of μm was microfibrillated into fibers with a diameter of several tens nm to 1 μm. It was

(2-1) (A) Fiber reinforced containing fibrillated acetylated Todomatsu (fibrillated Ac todomatsu) as MFC, (B) acetylated flax (Ac flax) as plant fiber, and (C) PA6 as thermoplastic resin Resin composition

Example 4 (Study No. PA6-645): Preparation of PA6 Composition Containing Fibrillated Ac Todomatsu (Ac-DS 0.67) and Ac Flax (Ac-DS 0.57), and Molded Article Thereof A PA6 composition containing Ac flax and a molded product thereof (composition ratio: PA6 / Ac Todomatsu / Ac flax = 82.1 / 12.1 / 5.8) were manufactured in the same manner as in Example 2 as described below.

  Instead of Ac Todomatsu P-2 (Ac-modified DS 0.7) and Ac Ramie (Ac-modified DS 0.33) used in Example 2, in this Example 4, Ac-Todomatsu P-3 (Ac-modified DS 0.67) and Ac flax were used. (Ac-modified DS 0.57) was used.

  First, the sheet-like Ac Todomatsu P-3 was treated in the same manner as in the preparation of the powdery MB-1 of Example 1 to obtain a powdery masterbatch containing Ac Todomatsu P-3 and PA6 powder (powder). MB-6, composition ratio: Ac Todomatsu P-3 / PA6 powder = 12.1 / 21.23).

  Next, in the same operation as in Example 2, PA6 powder and Ac flax were added to powdered MB-6, and a uniform mixture of each component (mixing ratio: powdered MB-6 / PA6 powder / Ac flax = 33.33 / 60.87 / 5.8) was prepared, melt-kneaded with the twin-screw melt-kneader and pelletized to contain fibrillated Ac todomatsu (Ac-modified DS 0.67) and Ac flax (Ac-modified DS 0.57). , A pelletized PA6 composition was obtained (composition ratio: PA6 / fibrillated Ac Todomatsu / Ac flax = 82.1 / 12.1 / 5.8).

Manufacture of molded product The obtained pellet was injection-molded in the same manner as in Example 2 to obtain a strip-shaped test piece (molded product) of width x length x thickness = 10 x 80 x 4 mm.

Example 5 (Test No. PA6-642): PA6 composition containing fibrillated Ac todomatsu (Ac-compound DS 0.67) and Ac flax (Ac-comprising DS 0.57), and production of a molded article thereof Same composition as in Example 4 A PA6 composition containing a ratio of fibrillated Ac Todomatsu and Ac flax, and a molded article thereof were manufactured in the same manner as in Example 3 as described below.

  In place of Ac todomatsu P-2 (Ac-modified DS 0.7) and Ac ramie (Ac-modified DS 0.33) used in Example 3, the same Ac-Todomatsu P-3 and Ac flax as in Example 4 were used in this Example 5. used.

  This production method includes Ac todomatsu P-3, PA6 powder, and Ac flax (composition ratio is Ac todomatsu P / PA6 powder / Ac flax = 12.1 / 32.1 / 5.8) powdery masterbatch (powdered MB-7 Referred to as), PA6 is added thereto, and the mixture is melt-kneaded to produce a PA6 composition containing fibrillated Ac todomatsu and Ac flax, which has the same composition as in Example 4 above.

  First, in the same operation as in the preparation of the powdered MB-3 of Example 3, the sheet-shaped Ac Todomatsu P-3 was treated and coarsely pulverized, powdered PA6 powder and Ac flax were added, mixed and dried. Thus, powdered MB-7 was prepared.

  Next, PA6 powder was added to powdered MB-7, and each component was mixed so as to be uniform in the same manner as in Example 4 (mixing ratio: powdered MB-7 / PA6 powder = 50/50). Then, the mixture was melt-kneaded and pelletized in the same manner as in Example 4 to obtain a PA6 composition containing fibrillated Ac Todomatsu and Ac flax having the same composition as in Example 4. This was injection-molded in the same manner as in Example 4 to obtain a molded body.

Comparative Example 5 (Test No. PA6-640): Preparation of PA6 Composition Containing Fibrillated Ac Todomatsu, and Molded Articles Thereof This is the control composition of Examples 4 and 5. The same sheet-like Ac Todomatsu P-3 (Ac-modified DS 0.67) used in Examples 4 and 5 and the powdered MB-6 (composition ratio: Ac Todomatsu / PA6 powder = 12.11 / 21.23) used in Example 4 were used. Then, the composition and the molded body were prepared by the following procedures.

  Powdered MB-6 and PA6 powder were mixed (mixing ratio: powdered MB-6 / PA6 powder = 33.3 / 66.67), uniformly mixed, and then melt-kneaded in the same manner as in Example 4, A kneaded composition consisting of PA6 and fibrillated Ac Todomatsu (composition ratio: PA6 / Ac Todomatsu = 87.9 / 12.1, PA6 / Ac Todomatsu = 90/10 when converted to an unmodified Todomatsu content composition ratio) was obtained. .. This was injection-molded in the same manner as described above to obtain a molded body.

Comparative Example 6 (Test No. PA6-641): Preparation of PA6 Composition Containing Ac Flax, and Molded Articles Thereof This is the control composition of Examples 4 and 5. Using the same Ac flax (Ac-modified DS 0.57) as in Examples 4 and 5, PA6 compositions and molded articles containing Ac flax were produced by the following method.

  PA6 powder was added to Ac flax to form a mixture having a composition ratio of PA6 powder / Ac flax = 88.4 / 11.6, which was uniformly mixed in a plastic bag and then melt-kneaded in the same manner as in Example 4 to obtain PA6 and Ac flax. Was obtained (composition ratio: PA6 powder / Ac flax = 88.4 / 11.6, PA6 / Ac flax = 90/10 when expressed in terms of unmodified flax content composition ratio). This was injection-molded in the same manner as described above to obtain a molded body.

(2-2) Test Results of Molded Body The flexural modulus, bending strength, and impact resistance of the above molded body (test piece) were measured by the above-described test methods. The results are shown in Table 2.

  In the composition content ratios in Table 2, the composition content ratios of the chemically modified fibers (Ac Todomatsu and Ac flax) are converted into the mass percentages of the corresponding unmodified fibers (Todomatsu and flax), respectively.

  The strength and elastic modulus of the molded bodies of Examples 4 and 5 are large and excellent as compared with those of the molded bodies of Comparative Examples 4 to 6. The impact resistance of the molded products of Examples 4 and 5 is not significantly lower than that of the molded products of Comparative Examples 4 to 6 even though the fiber content is increased.

(3-1) (A) Fiber reinforced containing fibrillated acetylated Todomatsu (fibrillated Ac todomatsu) as MFC, (B) acetylated abaca (Ac abaca) as plant fiber, and (C) PA6 as thermoplastic resin Resin composition

Example 6 (Study No. PA6-646): Preparation of PA6 Composition Containing Fibrillated Ac Todomatsu (Ac-DS 0.67) and Ac Abaca (Ac-DS 0.5), and Molded Product Thereof A PA6 composition containing Ac abaca and a molded product thereof were manufactured in the same manner as in Example 2 as described below.

  Instead of Ac todomatsu P-2 (Ac-modified DS 0.73) and Ac ramie (Ac-modified DS 0.33) used in Example 2, Ac-todomatsu P-3 (Ac-modified DS 0.67) and Ac abaca (Ac-modified DS 0.53) were used. )It was used.

  First, the sheet-shaped Ac Todomatsu P-3 (Ac-modified DS 0.67) was treated in the same manner as in the preparation of the powdery MB-1 of Example 1 to contain Ac Todomatsu P-3 and PA6 powder. To obtain powdery MB-6 (composition ratio: Ac Todomatsu / PA6 powder = 12.1 / 21.23).

  Next, in the same operation as in Example 2, PA6 powder and Ac abaca were added to powdered MB-6, and a uniform mixture of each component (mixing ratio: powdered MB-6 / PA6 powder / Ac abaca = 33.33 / 61 / 5.67), melt-kneading this with the biaxial melt-kneader, pelletizing, and containing fibrillated Ac Todomatsu (Ac-DS 0.67) and Ac-Abaca (Ac-DS 0.5) PA composition (composition ratio: PA6 / fibrillated Ac Todomatsu / Ac abaca = 82.23 / 12.1 / 5.67, unmodified Todomatsu content When expressed in terms of composition ratio, PA6 / Ac Todomatsu / Ac abaca = 85/10 / 5) got.

Manufacture of molded product The obtained pellet was injection-molded in the same manner as in Example 2 to obtain a strip-shaped test piece (molded product) of width x length x thickness = 10 x 80 x 4 mm.

Example 7 (Test No. PA6-644): PA6 composition containing fibrillated Ac Todomatsu (Ac-DS 0.67) and Ac-Abaca (Ac-DS 0.5), and manufacture of its molded article Same composition as in Example 6 A PA composition containing a ratio of fibrillated Ac Todomatsu and Ac abaca, and a molded article thereof were manufactured in the same manner as in Example 3 as described below.

  The same Ac Todomatsu P-3 and Ac Abaca used in Example 6 were used instead of the Ac Todomatsu P-2 (Ac-modified DS 0.7) and Ac ramie (Ac-modified DS 0.33) used in Example 3. did.

  In this production method, a master batch of Ac todomatsu / PA6 powder / Ac abaca was prepared, and this was melt-kneaded with PA6, and PA6 containing fibrillated Ac todomatsu and Ac abaca having the same composition as in Example 6 above. A method of producing a composition.

  First, a sheet of Ac Todomatsu P-3 was treated by the same operation as in the preparation of MB-3 of Example 3 and coarsely pulverized, and powder PA6 powder and Ac abaca were added, mixed and dried, A powdery mixture (composition ratio of Ac Todomatsu P / PA6 powder / Ac Abaca = 12.1 / 32.23 / 5.67, which is referred to as powdery MB-8) was prepared.

  Next, PA6 powder was added to powdered MB-8, and each component was mixed so as to be uniform in the same manner as in Example 6 (mixing ratio: powdered MB-8 / PA6 powder = 50/50). Then, the mixture was melt-kneaded and pelletized in the same manner as in Example 6 to obtain a PA6 composition containing fibrillated Ac Todomatsu and Ac abaca having the same composition as in Example 6. Then, this was injection-molded in the same manner as in Example 6 to obtain a molded body.

Comparative Example 7 (Test No. PA6-643): Preparation of PA6 Composition Containing Ac Abaca and Molded Articles Thereof This is the control composition of Examples 6 and 7. Using the Ac abaca used in Examples 6 and 7 (Ac-modified DS 0.5), a PA6 composition containing an Ac abaca was prepared by the following method.

  PA6 powder was added to Ac abaca to form a mixture having a composition ratio of PA6 powder / Ac abaca = 88.66 / 11.34, and after uniform mixing, melt kneading was carried out in the same manner as in Example 6 to obtain a kneading composition consisting of PA6 and Ac abaca. (Composition ratio: PA6 powder / Ac Abaca = 88.66 / 11.34) was obtained. Then, this was injection-molded in the same manner as described above to obtain a molded body.

(3-2) Test Result of Molded Body The flexural modulus, bending strength, and impact resistance of the above molded body (test piece) were measured by the above-mentioned test methods. The results are shown in Table 3.

  In the composition content ratios in Table 3, the composition content ratios of the chemically modified fibers (Ac Todomatsu and Ac Abaca) are shown in terms of the mass percentages of the corresponding unmodified fibers (Todomatsu and Abaca).

  The strength and elastic modulus of the molded bodies of Examples 6 and 7 are large and excellent as compared with those of the molded bodies of Comparative Examples 4, 5, and 7. The impact resistance of the molded products of Examples 6 and 7 is not much lower than that of the molded products of Comparative Examples 4, 5, and 7 even though the fiber content is increased.

(4-1) (A) MFC fibrillated acetylated Todomatsu (fibrillated Ac Todomatsu), (B) vegetable fiber kenaf (without chemical modification) or acetylated kenaf (Ac kenaf), and (C) thermoplastic resin Fiber-reinforced resin composition containing PA6 as

Example 8 (Test No. PA6-631): Production of PA6 Composition Containing Fibrillated Ac Todomatsu (Ac Derived DS 0.56) and Kenaf, and Molded Article Thereof Instead of ramie (no chemical modification), kenaf (no chemical modification) ) Is used in the same manner as in Example 1 to prepare a PA6 composition containing fibrillated Ac Todomatsu (DS 0.56 Ac) and kenaf, which is molded and processed to obtain fibrillated Ac Todomatsu (Ac). And a kenaf (without chemical modification) was prepared.

Example 9 (Test No. PA6-687): Production of a PA6 composition containing fibrillated Ac Todomatsu (Ac-compound DS 0.67) and Ac kenaf (Ac-compound DS 0.25), and a molded article thereof Ac-Todomatsu sheet P-2 Example 3 using sheet Ac Ac Todomatsu P-3 (Ac compound DS 0.67) instead of (Ac compound DS 0.7) and Ac kenaf (Ac compound DS 0.25) instead of Ac ramie (Ac compound DS 0.33) A PA6 composition containing fibrillated Ac todomatsu (Ac-modified DS 0.67) and Ac kenaf (Ac-modified DS 0.25) was prepared in the same manner as in 1., and molded to obtain a molded product.

Example 10 (Test No. PA6-688): Preparation of PA6 composition containing fibrillated Ac todomatsu (Ac-compound DS 0.67) and Ac kenaf (Ac-comprising DS 0.64), and molded article thereof
Fibrillated Ac todomatsu (Ac-compound DS 0.67) and Ac-kenaf (Ac-compound DS 0.25) were used in the same manner as in Example 9 except that Ac-kenaf (Ac-compound DS 0.25) was used. A PA6 composition containing DS 0.64) was prepared and molded to obtain a molded body.

Comparative Example 8 (Test No. PA6-682): Production of PA6 composition containing fibrillated Ac todomatsu (Ac-compound DS 0.67) and molded article thereof Instead of sheet-like Ac todomatsu P-2 (Ac-compound DS 0.7) A PA6 composition containing PA6 and fibrillated Ac Todomatsu P (Ac-modified DS 0.66) was prepared in the same manner as in Comparative Example 2 except that sheet-like Ac Todomatsu P-3 (Ac-modified DS 0.67) was used. This was molded to obtain a molded body.

(4-2) Test Results of Molded Body The flexural modulus, bending strength, and impact resistance of the above molded body (test piece) were measured by the above-described test methods. The results are shown in Table 4.

  In addition, in the composition content ratios in Table 4, the composition content ratios of the chemically modified fibers (Ac Todomatsu and Ac kenaf) are converted into mass percentages of the corresponding unmodified fibers (Todomatsu and kenaf).

  The strength and elastic modulus of the molded bodies of Examples 8 to 10 are larger and superior to those of the molded bodies of Comparative Examples 1, 4 and 8. The impact resistances of the molded products of Examples 8 to 10 are not much lower than those of the molded products of Comparative Examples 1, 4 and 8 even though the fiber content is increased.

Claims (10)

A fiber-reinforced resin composition containing (A) microfibrillated cellulosic fibers, (B) plant fibers, and (C) a thermoplastic resin,
A fiber-reinforced resin composition in which the (A) microfibrillated cellulosic fiber and the (B) plant fiber satisfy the following requirements (a) and (b), respectively.
Requirement (a):
(A) The microfibrillated cellulosic fiber has the following formula (1):
(Lg) Cell-OR (1)
[In the formula (1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin constituting cellulose, holocellulose and / or lignocellulose in the cellulosic polymer.
-OR represents a hydroxyl group in the cellulose and holocellulose and / or lignocellulosic polysaccharides and lignin in the cellulosic polymer, or a hydrogen atom of a part of the hydroxyl group is substituted with a substituent R. R represents a hydrogen atom, an acyl group having 2 to 4 carbon atoms, and the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and represent a hydrogen atom, a methyl group, an ethyl group, or an alkenyl group or an alkyl group having 3 to 20 carbon atoms which may have a branched chain. Provided that when ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a microfibrillated fiber of a fiber composed of a non-chemically modified or chemically modified cellulosic polymer represented by.
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group. R in the formula (1) of the requirement (a) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The fiber-reinforced resin composition according to claim 1, which is a carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.   The fiber-reinforced resin composition according to claim 1 or 2, wherein R in the formula (1) of the requirement (a) is an acetyl group.   The requirement (b) (B) vegetable fiber is (B-1) one or more vegetable fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton. The fiber-reinforced resin composition according to any one of claims 1 to 3.   The requirement (b) (B) vegetable fiber is (B-2) a part of hydrogen atoms of the hydroxyl groups of the cellulose constituting the (B-1) vegetable fiber is an acyl group having 2 to 4 carbon atoms. The fiber-reinforced resin composition according to any one of claims 1 to 3, which is one or more chemically modified plant fibers that have been modified.   The fiber-reinforced resin composition according to any one of claims 1 to 3, wherein the plant fiber (B) of the requirement (b) is a ramie and / or a ramie modified with an acetyl group.   The thermoplastic resin (C) is polyamide, polyolefin, aliphatic polyester, aromatic polyester, polyacetal, polycarbonate, polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate-ABS alloy (PC-ABS alloy). And at least one resin selected from the group consisting of modified polyphenylene ether (m-PPE), and the fiber-reinforced resin composition according to claim 1.   A molded product comprising the fiber-reinforced resin composition according to claim 1. A method for producing a fiber-reinforced resin composition containing (A-1) a chemically modified microfibrillated cellulosic fiber, (B) a plant fiber, and (C) a thermoplastic resin,
(AP) chemically modified cellulosic pulp, (B) vegetable fiber, and (C) thermoplastic resin is melt-kneaded, and the step of microfibrillating the chemically modified cellulosic pulp during the melt-kneading,
The (AP) chemically modified cellulosic pulp, the (B) plant fiber, and the (A-1) chemically modified microfibrillated cellulosic fiber have the following requirements (ap), (b), and (a-1), respectively. ), The manufacturing method.
Requirements (ap):
(AP) Chemically modified cellulosic pulp has the following formula (1-1):
(Lg) Cell-OR (1-1)
[In the formula (1-1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin that constitute cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer. -OR indicates that some of the hydrogen atoms of the hydroxyl groups in the polysaccharide and lignin constituting the cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer are replaced by the substituent R, and R is , An acyl group having 2 to 4 carbon atoms, the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and represent a hydrogen atom, a methyl group, an ethyl group, or an alkenyl group or an alkyl group having 3 to 20 carbon atoms which may have a branched chain. Provided that when either ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a chemically modified cellulosic pulp composed of a chemically modified cellulosic polymer.
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.
Requirement (a-1):
The (A-1) chemically modified microfibrillated cellulosic fiber is a microfibrillated fiber composed of the chemically modified cellulosic polymer represented by the formula (1-1). A method for producing a fiber-reinforced resin composition containing (A-1) a chemically modified microfibrillated cellulosic fiber, (B) a plant fiber, and (C) a thermoplastic resin,
Process (1):
(AP) a chemically modified cellulosic pulp and (C) a thermoplastic resin are kneaded to microfibrillize the chemically modified cellulosic pulp during the melt-kneading, and step (2):
Including the step of compounding the kneaded product obtained in the step (1), and (B) plant fiber, or a resin composition containing a plant fiber and a thermoplastic resin,
The (AP) chemically modified cellulosic pulp, the (B) plant fiber, and the (A-1) chemically modified microfibrillated cellulosic fiber have the following requirements (ap), (b), and (a-1), respectively. ), The manufacturing method.
Requirements (ap):
(AP) Chemically modified cellulosic pulp has the following formula (1-1):
(Lg) Cell-OR (1-1)
[In the formula (1-1), (Lg) Cell- represents a residue obtained by removing a hydroxyl group from the polysaccharide and lignin that constitute cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer. -OR indicates that some of the hydrogen atoms of the hydroxyl groups in the polysaccharide and lignin constituting the cellulose, holocellulose, and / or lignocellulose in the cellulosic polymer are replaced by the substituent R, and R is , An acyl group having 2 to 4 carbon atoms, the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and represent a hydrogen atom, a methyl group, an ethyl group, or an alkenyl group or an alkyl group having 3 to 20 carbon atoms which may have a branched chain. Provided that when either ^one of R ¹ and R ² has 4 to 20 carbon atoms, the other of R ¹ and R ² is a hydrogen atom.), Or a carboxy group-containing acyl group represented by A salt of a group-containing acyl group is shown. ]
It is a chemically modified cellulosic pulp composed of a chemically modified cellulosic polymer.
Requirement (b):
(B) vegetable fiber
(B-1) one or more plant fibers selected from the group consisting of ramie, hemp, linen, jute, abaca, sisal, kenaf, and cotton, or
(B-2) A part of hydrogen atoms of a hydroxyl group of cellulose constituting the plant fiber of (B-1) is an acyl group having 2 to 4 carbon atoms, and the following formula (2):
(In the formula (2), R ¹ and R ² are the same or different and each represents a hydrogen atom, a methyl group, an ethyl group, or an optionally branched alkenyl group or alkyl group having 3 to 20 carbon atoms. However, when the carbon number of either R ¹ or R ² is 4 to 20, the other of R ¹ and R ² is a hydrogen atom.)
The one or more chemically modified plant fibers modified with the carboxy group-containing acyl group represented by or a salt of the carboxy group-containing acyl group.
Requirement (a-1):
The (A-1) chemically modified microfibrillated cellulosic fiber is a microfibrillated fiber composed of the chemically modified cellulosic polymer represented by the formula (1-1).