JP2020063321A - Fiber reinforced resin composition and manufacturing method therefor - Google Patents

Abstract

To provide a fiber reinforced resin composition capable of maintaining flexibility even thought it contains a cellulose nanofiber.SOLUTION: A resin composition is manufactured by combining a thermoplastic resin (A), a cellulose nanofiber (B) which may be modified, and polysilane (C). The cellulose nanofiber (B) may contain a modified cellulose fiber in which a fluorene compound having an aryl group at a 9,9 position is bound. The thermoplastic resin (A) may be a polypropylene resin. A mass ration of the thermoplastic rein (A) and the cellulose nanofiber (B) is former:later=99/1 to 70/30. Percentage of the polysilane (C) is 0.1 to 10 pts.mass based on total amount 100 pts.mass of the thermoplastic rein (A) and the cellulose nanofiber (B).SELECTED DRAWING: None

Description

  TECHNICAL FIELD The present invention relates to a fiber reinforced resin composition reinforced with cellulose nanofibers and a method for producing the same.

  Cellulose nanofibers (CNFs) are lightweight, have excellent strength and elastic modulus, have a low linear expansion coefficient, and have recently attracted attention as a new reinforcing agent for plastics because they are materials derived from biomass. However, as described in FIG. 6 of Biomacromolecules, Vol. 10, No. 2, 2009, 425-432 (Non-Patent Document 1), a reinforcing agent having a large specific surface area such as cellulose nanofibers is generally used. Tends to significantly reduce the flexibility of the resin depending on the amount added.

  In addition, Japanese Patent Laid-Open No. 2013-248824 (Patent Document 1) discloses a molded body composed of a composite material containing cellulose nanofibers in a resin, and having a minimum thickness of 1 μm or more. And a surface layer that covers the surface of the core material portion, which is made of a second composite material containing a cellulose nanofiber aggregate having a minimum thickness of 1 μm or more. A molded body comprising is disclosed.

  However, even in this molded product, if the proportion of cellulose nanofibers increases, the flexibility decreases and the moldability also decreases.

JP, 2013-248824, A

Biomacromolecules, Vol. 10, No. 2, 2009, 425-432 (Figure 6)

  Therefore, an object of the present invention is to provide a fiber-reinforced resin composition that can maintain flexibility even when it contains cellulose nanofibers, and a method for producing the same.

  Another object of the present invention is to provide a fiber reinforced resin composition having a low linear thermal expansion coefficient at high temperature and a method for producing the same.

  The present inventors have conducted intensive studies to achieve the above-mentioned problems, and in combination with cellulose nanofibers and polysilane, by blending with a thermoplastic resin, even if the cellulose nanofibers are contained, the flexibility can be maintained. And completed the present invention.

  That is, the resin composition of the present invention contains a thermoplastic resin (A), optionally modified cellulose nanofibers (B) and polysilane (C). The cellulose nanofiber (B) may include a modified cellulose nanofiber (B1) to which a fluorene compound having an aryl group at the 9,9 position is bonded. The fluorene compound may be a compound represented by the following formula (1).

(In the formula, ring Z is an arene ring, R ¹ and R ² are substituents, X ¹ is a heteroatom-containing functional group, k is an integer of 0 to 4, n is an integer of 1 or more, and p is an integer of 0 or more. Shown).

In the formula (1), X ¹ represents a group — [(OA) _m1 —Y ¹ ] (in the formula, A represents an alkylene group, Y ¹ represents a hydroxyl group or a glycidyloxy group, and m1 represents an integer of 0 or more). May be The ratio of the fluorene compound may be 0.01 to 33 mass% in the modified cellulose nanofiber (B1). The average fiber diameter of the cellulose nanofiber (B) may be 3 to 500 nm. The polysilane (C) may have at least one structural unit among the structural units represented by the following formulas (2) and (3).

(In the formula, R ^{3 to} R ⁵ are the same or different and represent a hydrogen atom, a hydroxyl group, an organic group or a silyl group).

  The polysilane (C) may be a polyalkylarylsilane having a weight average molecular weight of 100 to 10,000. The thermoplastic resin (A) may be an olefin resin (particularly a polypropylene resin). The mass ratio of the thermoplastic resin (A) to the cellulose nanofiber (B) may be the former / the latter = 99/1 to 70/30. The ratio of the polysilane (C) may be 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of the thermoplastic resin (A) and the cellulose nanofiber (B).

  In the present invention, the resin composition including a mixing step of mixing (particularly, melt kneading) the thermoplastic resin (A), the cellulose nanofiber (B) and / or its raw material, and the polysilane (C). It also includes a method of manufacturing a product.

  In the present invention, since the cellulose nanofibers and polysilane are combined and blended with the thermoplastic resin, the flexibility can be maintained even if the cellulose nanofibers are included. In particular, when modified cellulose nanofibers having a compound having a 9,9-bis (aryl) fluorene skeleton bonded thereto are used as the cellulose nanofibers, a resin composition having a low linear thermal expansion coefficient at high temperature can be effectively prepared.

FIG. 1 is a scanning electron microscope (SEM) photograph of cellulose nanofibers used in the examples. FIG. 2 is a graph showing the coefficient of linear thermal expansion of the films obtained in Example 1 and Comparative Examples 1-2.

  The resin composition of the present invention contains a thermoplastic resin (A), optionally modified cellulose nanofibers (B), and polysilane (C).

[Thermoplastic resin (A)]
Examples of the thermoplastic resin (A) include olefin resins (poly-α-C _2-6 olefin resins such as polyethylene resins, polypropylene resins, polymethylpentene resins, and cyclic olefin resins such as norbornene resins). Modified olefin resin (halogenated olefin resin such as chlorinated polyethylene, cross-linked olefin resin such as cross-linked polypropylene, graft copolymer such as maleic anhydride graft polyethylene, ethylene-vinyl acetate copolymer (EVA), Copolymers such as ethylene-vinyl alcohol copolymers); Vinyl chloride resins (polyvinyl chloride resins, polyvinylidene chloride resins, etc.); Vinyl acetate resins (polyvinyl acetate or its derivatives (polyvinyl alcohol, polyvinyl) (Acetal etc.) etc.); Resins (polystyrene; styrene copolymers such as acrylonitrile-styrene copolymer (AS resin), impact-resistant polystyrene resins, rubber-reinforced polystyrene resins such as acrylonitrile-butadiene-styrene copolymer); ( (Meth) acrylic resin; polyester resin [homogeneous or copolymerized polyester having a C _2-4 alkylene C _6-12 arylate unit such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, poly (1, 4-cyclohexyl dimethylene terephthalate) and other C _5-10 cycloalkylenedi C _1-4 alkylene C _6-12 arylates, polyphenylene arylates and other wholly aromatic polyesters (polyarylate), etc.]; Carbonate-based resins (bisphenol A-type polycarbonate resins and the like); Polyamide-based resins (polyamide 6, polyamide 6-6 and other aliphatic polyamides, cycloalkanedicarboxylic acids and diamines and other alicyclic polyamides, MXD-6, Aromatic polyamide formed from terephthalic acid and trimethylhexamethylenediamine, etc.); Polyether resin (polyphenylene ether resin, polyether ketone resin, polyether ether ketone resin, etc.); Polyphenylene sulfide resin; Polysulfone -Based resin (polysulfone resin, polyethersulfone-based resin, etc.); polyacetal-based resin; fluorine-based resin (polytetrafluoroethylene, etc.); liquid crystal plastic (liquid crystal polyester, etc.); thermoplastic elastomer (ole Fin elastomers, styrene elastomers, ester elastomer, amide elastomer, vinyl chloride elastomer, and fluorine-based elastomers) and the like. These thermoplastic resins may be contained alone or in combination of two or more kinds.

  Of these, olefin-based resins, styrene-based resins, polyester-based resins, polycarbonate-based resins, polyamide-based resins, etc. are widely used from the viewpoint of mechanical properties and moldability, and have excellent compatibility with polysilane (C). The olefin resin is preferable because it has a large effect of improving the flexibility of the polysilane (C), and the polypropylene resin is particularly preferable because it has an excellent balance of various properties such as heat resistance.

As the polypropylene resin, isotactic polypropylene (NZ catalyst system or metallocene catalyst system), syndiotactic polypropylene, atactic polypropylene, propylene-ethylene copolymer, propylene-C _4-6 alkene copolymer (for example, , Propylene-butene copolymers, etc.). The proportion of propylene units (propylene content) in the polypropylene-based resin may be 70 mol% or more based on the total amount of the polypropylene-based resin, for example, 75 to 100 mol%, preferably 80 to 100 mol%, more preferably 90. May be up to 100 mol%.

  The form of copolymerization is not particularly limited, and may be, for example, random copolymerization, alternating copolymerization, block copolymerization, or graft copolymerization.

The molecular weight of the thermoplastic resin (A) (in particular, olefin resin such as polypropylene resin) is not particularly limited, and the weight average molecular weight (unit: × 10 ⁴ ) is, for example, 0.1 to 100, preferably 1 The degree of dispersion (Mw / Mn) may be, for example, 1 to 5, preferably 1 to 3, more preferably 1 to 2, and particularly 1 to 1.5. May be The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin can be measured in terms of polystyrene by GPC (Gel Permeation Chromatography, gel permeation chromatography).

  The melting point of the thermoplastic resin (A) (particularly, olefin resin such as polypropylene resin) is, for example, 100 to 190 ° C. (for example, 100 to 180 ° C.), preferably 130 to 170 ° C., and more preferably 140 to 165 ° C. ( Particularly, it is about 145 to 160 ° C.). If the melting point of the thermoplastic resin (A) is too low, the heat resistance may decrease, and if it is too high, the moldability may decrease.

  The melt flow rate (MFR) of the thermoplastic resin (A) (in particular, olefin resin such as polypropylene resin) is a method according to JIS K 7210 (for example, test temperature: 230 ° C., test load: 2.16 kg). It is, for example, about 1 to 100 g / 10 minutes, preferably 5 to 80 g / 10 minutes, and more preferably 10 to 50 g / 10 minutes (particularly 20 to 40 g / 10 minutes). If the MFR of the thermoplastic resin (A) is too low, the heat resistance may decrease, and if it is too high, the moldability may decrease.

[Cellulose nanofibers (B) which may be modified]
The resin composition of the present invention can improve the mechanical strength and heat resistance of the resin composition by blending the cellulose nanofiber (B) which may be modified with the thermoplastic resin (A). . The cellulose nanofiber (B) may be unmodified cellulose nanofiber or modified cellulose nanofiber.

  Cellulose nanofibers (or cellulose nanofibers) constituting the cellulose nanofibers (B) are cellulose fibers obtained by micronizing (or microfibrillating) cellulose (cellulose raw material) to nanometer size, or nanometer-sized cellulose derived from microorganisms. It is fiber. The cellulose nanofibers, lignin, pulp with a low content of non-cellulose components such as hemicellulose, for example, plant-derived cellulose raw material {for example, wood [for example, conifer (pine, fir, spruce, hemlock, cedar, etc.), Hardwood (beech, hippopotamus, poplar, maple, etc.), herbs (linen (hemp, flax, Manila hemp, ramie, etc.), straw, bagasse, mitsumata, etc.), seed hair fiber (cotton linter, bombax cotton, kapok) Etc.), bamboo, sugar cane etc.}, animal-derived cellulose raw materials (such as ascidian cellulose), bacterial-derived cellulose raw materials (such as cellulose contained in nata de coco), and the like, and pulp-derived cellulose nanofibers. These cellulose nanofibers can be used alone or in combination of two or more kinds. Among these cellulose nanofibers, cellulose nanofibers derived from wood pulp (eg, softwood pulp, hardwood pulp, etc.) and seed hair fiber pulp (eg, cotton linter pulp) are preferable. The pulp may be mechanical pulp obtained by mechanically treating the pulp material, but chemical pulp obtained by chemically treating the pulp material is preferable because the content of the non-cellulose component is small.

  Among these, modified cellulose nanofibers are preferable, modified cellulose nanofibers having a compound having an aromatic ring bonded thereto are more preferable, and fluorene having an aryl group at the 9- and 9-positions is preferable, because the flexibility and the heat resistance can be highly improved. A modified cellulose nanofiber (B1) having a compound bound thereto is particularly preferable.

(Fluorene compound)
The fluorene compound having an aryl group at the 9th and 9th positions serves as a functional group that constitutes the modified cellulose nanofiber (B1), and serves as a compatibilizer or dispersant for uniformly dispersing the cellulose nanofiber in the thermoplastic resin. The mechanical properties of the resin composition can be greatly improved, probably because the cellulose nanofibers are more highly uniformly dispersed in the thermoplastic resin (A) by the combination with the polysilane (C) which functions and is described later. A resin composition having a low linear thermal expansion coefficient at high temperature can be effectively prepared.

  Such a fluorene compound may be a compound having a 9,9-bisarylfluorene skeleton, and may be, for example, the fluorene compound represented by the formula (1).

  In the above formula (1), examples of the arene ring represented by the ring Z include a monocyclic arene ring such as a benzene ring and a polycyclic arene ring. The polycyclic arene ring includes a condensed polycyclic arene. A ring (fused polycyclic hydrocarbon ring), a ring-collecting arene ring (ring-collecting aromatic hydrocarbon ring) and the like are included.

Examples of the condensed polycyclic arene ring include a condensed bicyclic arene ring (for example, a condensed bicyclic C _10-16 arene ring such as a naphthalene ring), a condensed tricyclic arene (for example, an anthracene ring, a phenanthrene ring, etc.). And a fused bi- to tetracyclic arene ring. Examples of preferable fused polycyclic arene ring include naphthalene ring and anthracene ring, and naphthalene ring is particularly preferable.

Examples of the ring-assembled arene ring include a biarene ring [eg, biphenyl ring, binaphthyl ring, phenylnaphthalene ring (eg, 1-phenylnaphthalene ring, 2-phenylnaphthalene ring, etc.) and other biC _6-12 arene ring], terarene Examples thereof include a ring (for example, a ter C _6-12 arene ring such as a terphenylene ring). Preferred ring-assembled arene rings include biC _6-10 arene rings, especially biphenyl rings.

  The two rings Z substituting at the 9-position of fluorene may be different or the same, but usually, they are often the same ring. Of the ring Z, a benzene ring, a naphthalene ring, a biphenyl ring (particularly a benzene ring) and the like are preferable.

  In addition, the substitution position of the ring Z substituting at the 9-position of fluorene is not particularly limited. For example, when the ring Z is a naphthalene ring, the group corresponding to the ring Z substituting at the 9-position of fluorene may be a 1-naphthyl group, a 2-naphthyl group or the like.

Examples of the hetero atom-containing functional group represented by X ¹ include a functional group having, as a hetero atom, at least one selected from oxygen, sulfur and nitrogen atoms. The number of heteroatoms contained in such a functional group is not particularly limited, but may be usually 1 to 3, and preferably 1 or 2.

Examples of the functional group, for example, group ^{_{- [(OA) m1 -Y 1}} ] ( wherein, ^{Y 1} is a hydroxyl group, glycidyloxy group, an amino group, N-substituted amino group or a mercapto group, A is an alkylene group , M1 is an integer of 0 or more), a group — (CH ₂ ) _{m 2} —COOR ³ (in the formula, R ³ is a hydrogen atom or an alkyl group, and m 2 is an integer of 0 or more).

Group - in ^{_{[(OA) m1 -Y 1]}} , as the N-substituted amino group of ^{Y 1,} for example, N- monoalkylamino group (N- mono _{C 1-4} alkylamino group such as methylamino, ethylamino group Etc.), N-monohydroxyalkylamino groups such as hydroxyethylamino groups (N-monohydroxyC _1-4 alkylamino groups, etc.) and the like.

The alkylene group A includes a straight chain or branched chain alkylene group, and examples of the straight chain alkylene group include a C _2-6 alkylene group (preferably a straight chain) such as an ethylene group, a trimethylene group, and a tetramethylene group. A chain C _2-4 alkylene group, more preferably a straight chain C _2-3 alkylene group, particularly an ethylene group) can be exemplified, and examples of the branched chain alkylene group include a propylene group, a 1,2-butanediyl group, Examples thereof include a branched C _3-6 alkylene group such as a 1,3-butanediyl group (preferably a branched C _3-4 alkylene group, particularly a propylene group).

  M1 representing the number of repeating oxyalkylene groups (OA) (average number of moles added) may be 0 or an integer of 1 or more (for example, 0 to 15, preferably about 0 to 10), for example, 0 to 8 (for example, 1-8), preferably 0-5 (eg 1-5), more preferably 0-4 (eg 1-4), especially 0-3 (eg 1-3), usually 0-. It may be 2 (eg 0 or 1). When m1 is 2 or more, the types of the alkylene group A may be the same or different. Further, the types of the alkylene group A may be the same or different in the same or different ring Z.

Group - in (CH _{2) m2} -COOR ^3, the alkyl group represented by ^{R 3,} methyl, ethyl, propyl, isopropyl, butyl, straight or branched chain, such as t- butyl group An example is a C _1-6 alkyl group. Preferred alkyl groups are C _1-4 alkyl groups, especially C _1-2 alkyl groups. M2, which represents the number of repeating methylene groups (average number of moles added), may be 0 or an integer of 1 or more (for example, 1 to 6, preferably 1 to 4, and more preferably about 1 to 2). m2 may typically be 0 or 1-2.

Among these, the group X ¹ is preferably a group — [(OA) _m1 —Y ¹ ] (in the formula, A is an alkylene group, Y ¹ is a hydroxyl group or a glycidyloxy group, and m1 is an integer of 0 or more). , Y ¹ is a glycidyloxy group-[(OA) _{m 1} -Y ¹ ] [wherein A is a C _2-6 alkylene group such as an ethylene group (for example, a C _2-4 alkylene group, particularly C _2-3 Alkylene group), Y ¹ is a glycidyloxy group, and m 1 is an integer of 0 to 5 (for example, 0 or 1)] is particularly preferable.

In the formula (1), n indicating the number of the groups X ¹ substituted on the ring Z may be 1 or more, preferably 1 to 3, more preferably 1 or 2 (particularly 1). The number of substitutions n may be the same or different in each ring Z.

The group X ¹ can be substituted at an appropriate position on the ring Z, for example, when the ring Z is a benzene ring, it is substituted at the 2,3,4 position (particularly the 3 and / or 4 position) of the phenyl group. When the ring Z is a naphthalene ring, it is often substituted at any of the 5- to 8-positions of the naphthyl group, for example, 1-position of the naphthalene ring with respect to the 9-position of fluorene. Position or 2 position (substitution with 1-naphthyl or 2-naphthyl relation) and 1,5-position, 2,6-position or the like with respect to this substitution position (especially when n is 1, In many cases, the group X ¹ is substituted in the (2, 6-position relationship). Further, when n is 2 or more, the substitution position is not particularly limited. Further, in the ring-assembled arene ring Z, the substitution position of the group X ¹ is not particularly limited, and, for example, even if it is substituted with an arene ring bonded to the 9-position of fluorene and / or an arene ring adjacent to this arene ring. Good. For example, the 3-position or 4-position of the biphenyl ring Z may be bonded to the 9-position of fluorene, and when the 3-position of the biphenyl ring Z is bonded to the 9-position of fluorene, the substitution position of the group X ¹ is It may be at any of the 2,4,5,6,2 ′, 3 ′, 4 ′ positions, and preferably may be substituted at the 6 position.

In the above formula (1), as the substituent R ² , a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom), an alkyl group (methyl group, ethyl group, propyl group, isopropyl group, butyl group, Linear or branched C _1-10 alkyl group such as s-butyl group and t-butyl group, preferably linear or branched C _1-6 alkyl group, and more preferably linear or branched chain etc. Jo _{C 1-4} alkyl group), a cycloalkyl group (cyclopentyl group and _{C 5-10} cycloalkyl groups such as cyclohexyl group), an aryl group [phenyl group, alkylphenyl group (methylphenyl (tolyl) group, dimethylphenyl (xylyl), etc. group), biphenyl group, _{C 6-12} aryl group such as a naphthyl group, an aralkyl group (benzyl group, a phenethyl group _{C 6-10} an aryl _{-C 1-4} alkyl group), alkoxy groups (e.g., methoxy group, an ethoxy group, a propoxy group, n- butoxy group, isobutoxy group, a linear or branched chain, such as t- butoxy C _1-10 alkoxy group, etc.), cycloalkoxy group (for example, C _5-10 cycloalkyloxy group such as cyclohexyloxy group), aryloxy group (for example, C _6-10 aryloxy group such as phenoxy group) Etc.), an aralkyloxy group (for example, a C _6-10 aryl-C _1-4 alkyloxy group such as a benzyloxy group), an alkylthio group (for example, a methylthio group, an ethylthio group, a propylthio group, an n-butylthio group, t A C _1-10 alkylthio group such as a butylthio group), a cycloalkylthio group (eg, a cycloalkylthio group) A C _5-10 cycloalkylthio group such as a hexylthio group, an arylthio group (eg, a C _6-10 arylthio group such as a thiophenoxy group), an aralkylthio group (eg a C _6-10 aryl such as a benzylthio group) Examples thereof include a -C _1-4 alkylthio group), an acyl group (for example, a C _1-6 acyl group such as an acetyl group), a nitro group, a cyano group and the like.

Of these substituents R ² , typically, a halogen atom, a hydrocarbon group (alkyl group, cycloalkyl group, aryl group, aralkyl group), an alkoxy group, an acyl group, a nitro group, a cyano group, a substituted amino group. And so on. Preferable substituent R ² is an alkoxy group (linear or branched C _1-4 alkoxy group such as methoxy group), particularly an alkyl group (particularly linear or branched C ₁ such as methyl group). _1-4 alkyl groups) are preferred. When the substituent R ² is an aryl group, the substituent R ² together with the ring Z may form the ring-collecting arene ring. The types of the substituent R ² may be the same or different in the same or different ring Z.

The coefficient p of the substituent R ² can be appropriately selected depending on the type of the ring Z, and may be, for example, an integer of 0 to 8, an integer of 0 to 4, preferably 0 to 3 (for example, 0 to 2). ), More preferably 0 or 1. In particular, when p is 1, the ring Z may be a benzene ring, a naphthalene ring or a biphenyl ring, and the substituent R ² may be a methyl group.

As the substituent R ¹ , a cyano group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), a carboxyl group, an alkoxycarbonyl group (for example, a C _1-4 alkoxy-carbonyl group such as a methoxycarbonyl group, etc.), alkyl Examples thereof include groups (C _1-6 alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group) and aryl groups (C _6-10 aryl groups such as phenyl group).

Among these substituents R ¹ , a linear or branched C _1-4 alkyl group (in particular, a C _1-3 alkyl group such as a methyl group), a carboxyl group or a C _1-2 alkoxy-carbonyl group, cyano A group and a halogen atom are preferable. The substitution number k is an integer of 0 to 4 (for example, 0 to 3), preferably an integer of 0 to 2 (for example, 0 or 1), and particularly 0. The substitution numbers k may be the same or different from each other, and when k is 2 or more, the types of the substituents R ¹ may be the same or different from each other, and the two benzene rings of the fluorene ring are substituted. The types of the substituents R ¹ may be the same or different. The substitution position of the substituent R ¹ is not particularly limited, and may be, for example, the 2nd to 7th positions (2nd, 3rd and / or 7th etc.) of the fluorene ring.

Among these, preferred fluorene compound, group ^{X 1} is a group - if it is ^{_{[(OA) m1 -Y 1]}} ( in the formula, shown ^{Y 1} is a hydroxyl group), for example, 9,9-bis ( 9,9-bis (hydroxy C _6-, such as 4-hydroxyphenyl) fluorene, 9,9-bis (6-hydroxy-2-naphthyl) fluorene and 9,9-bis (5-hydroxy-1-naphthyl) fluorene. ₁₂ aryl) fluorene; 9,9-bis (3,4-dihydroxyphenyl) fluorene, 9,9-bis (3,5-dihydroxyphenyl) fluorene and other 9,9-bis (di- or trihydroxy C _6-12) Aryl) fluorene; 9,9-bis (3-methyl-4-hydroxyphenyl) fluorene, 9,9-bis (3,5-dimethyl-4-hydroxyphenyl) 9,9-bis fluorene (mono- or _{di-C 1-4} alkyl - hydroxy _{C 6-12} aryl) fluorene; 9,9-bis (3-phenyl-4-hydroxyphenyl) fluorene, 9,9-bis ( 9,9-bis (C _6-12 aryl-hydroxy C _6-12 aryl) fluorene such as 4-phenyl-3-hydroxyphenyl) fluorene; 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene , 9,9-bis [6- (2-hydroxyethoxy) -2-naphthyl] fluorene such as 9,9-bis (hydroxy _{(poly) C 2-4} alkoxy _{-C 6-12} aryl) fluorene; 9,9 - bis [3-methyl-4- (2-hydroxyethoxy) phenyl] fluorene such as 9,9-bis _{(C 1-4} alkyl - hydroxy _{Poly) C 2-4} alkoxy _{-C 6-12} aryl) fluorene; 9,9-bis [3-phenyl-4- (2-hydroxyethoxy) phenyl] fluorene, 9,9-bis [4-phenyl-3- Examples include 9,9-bis (C _6-12 aryl-hydroxy (poly) C _2-4 alkoxy-C _6-12 aryl) fluorene such as (2-hydroxyethoxy) phenyl] fluorene.

Group ^{X 1} is a group ^{_{- [(OA) m1 -Y 1}} ] Preferred fluorene compounds when (wherein, ^{Y 1} represents a glycidyloxy group), 9,9-bis (glycidyloxy aryl) fluorene , For example, 9,9-bis (3-glycidyloxyphenyl) fluorene, 9,9-bis (4-glycidyloxyphenyl) fluorene, 9,9-bis (5-glycidyloxy-1-naphthyl) fluorene, 9, 9,9-bis (glycidyloxy _C6-10 aryl) fluorene such as 9-bis (6-glycidyloxy-2-naphthyl) fluorene; 9,9-bis (glycidyloxy (poly) alkoxyaryl) fluorene, for example, 9,9-bis (4- (2-glycidyloxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-gly Diloxypropoxy) phenyl) fluorene, 9,9-bis (5- (2-glycidyloxyethoxy) -1-naphthyl) fluorene, 9,9-bis (6- (2-glycidyloxyethoxy) -2-naphthyl) 9,9-bis fluorene (glycidyloxy _{(poly) C 2-4} alkoxy _{C 6-10} aryl) fluorene; 9,9-bis (alkyl - glycidyloxy aryl) fluorene, e.g., 9,9-bis (3 -Methyl-4-glycidyloxyphenyl) fluorene, 9,9-bis (3,5-dimethyl-4-glycidyloxyphenyl) fluorene and other 9,9-bis (mono or diC _1-4 alkyl-glycidyloxy C _6-10 aryl) fluorene; 9,9-bis (alkyl - glycidyloxy (poly) Arukokishiari Le) fluorene, e.g., 9,9-bis (3-methyl-4- (2-glycidyloxyethoxy) phenyl) fluorene such as 9,9-bis (mono- or _{di-C 1-4} alkyl - glycidyloxy (poly) C _2-4 alkoxy C _6-10 aryl) fluorene; 9,9-bis (aryl-glycidyloxyaryl) fluorene, for example, 9,9-bis (3-phenyl-4-glycidyloxyphenyl) fluorene 9, 9-bis ( _C6-10 aryl-glycidyloxy _C6-10 aryl) fluorene; 9,9-bis (aryl-glycidyloxy (poly) alkoxyaryl) fluorene, for example 9,9-bis (4-phenyl-). 9,9-bis (C _6-10 ants such as 3- (2-glycidyloxyethoxy) phenyl) fluorene Lumpur - glycidyloxy _{(poly) C 2-4} alkoxy _{C 6-10} aryl) fluorene; 9,9-bis (di (glycidyloxy) aryl) fluorene, e.g., 9,9-bis (3,4-di ( 9,9-bis (di (glycidyloxy) C _6-10 aryl) fluorene such as glycidyloxy) phenyl) fluorene and 9,9-bis (3,5-di (glycidyloxy) phenyl) fluorene; 9,9- Bis (di (glycidyloxy (poly) alkoxy) aryl) fluorene, for example, 9,9-bis (3,4-di (2-glycidyloxyethoxy) phenyl) fluorene, 9,9-bis (3,5-di) (2-glycidyloxyethoxy) phenyl) fluorene such as 9,9-bis (di (glycidyloxy _{(poly) C 2-4 alkoxy) C 6- 0} aryl) fluorene, and others.

  These fluorene compounds can be used alone or in combination of two or more. In addition, "(poly) alkoxy" is used to mean both an alkoxy group and a polyalkoxy group.

(Modified Cellulose Nanofiber (B1) and Manufacturing Method Thereof)
The modified cellulose nanofiber (or modified cellulose nanofiber) (B1) is a cellulose derivative in which the unmodified cellulose nanofiber and the fluorene compound are bonded.

The form of chemical modification (or binding) of the modified cellulose nanofiber (B1) is not particularly limited, and for example, when the fluorene compound is the fluorene compound represented by the above formula (1), the reactive group (hetero) of the fluorene compound is It can be appropriately selected depending on the type of atom-containing functional group). Specifically, in the formula (1), when X ¹ is — [(OA) _m1 —Y ¹ ] (and Y ¹ is a hydroxyl group, the hydroxyl group and / or the carboxyl group of the cellulose nanofibers are used. May be an ether bond and / or an ester bond with the hydroxyl group of the fluorene compound represented by the above formula (1), and when Y ¹ is a glycidyloxy group, the hydroxyl group and / or the carboxyl of the cellulose nanofiber The group may be an ether bond and / or an ester bond between the glycidyl group of the fluorene compound represented by the formula (1) and the carboxyl group of the cellulose nanofiber is formed during the production process of pulp or the like. There are cases.

  The modified cellulose nanofiber (B1) may be produced by reacting an unmodified cellulose nanofiber as a raw material with the fluorene compound in the absence or presence of a predetermined catalyst, and the modified cellulose nanofiber (B1) may be produced in the thermoplastic resin (A). In the above, it may be produced by reacting unmodified cellulose nanofibers with the fluorene compound in the process of kneading.

  The ratio of the unmodified cellulose nanofiber as a raw material can be selected according to the reactive group of the fluorene compound, but is, for example, 0.1 to 500 parts by mass (for example, 1 to 300 parts by mass) with respect to 100 parts by mass of the fluorene compound. It can be selected from a range of about 5 to 200 parts by mass (particularly 10 to 150 parts by mass).

  When a catalyst is used, the catalyst can also be selected according to the reactive group of the fluorene compound, and when the reactive group is a hydroxyl group, an acid catalyst may be used. As the acid catalyst, Bronsted acid, for example, inorganic acid such as sulfuric acid, hydrochloric acid, phosphoric acid, organic acid such as p-toluenesulfonic acid, solid acid [for example, heteropoly acid (tungsten-based heteropoly acid, molybdenum-based heteropoly acid, etc. ), Cation exchange resins (strongly acidic cation exchange resins having sulfonic acid groups, fluorine-containing cation exchange resins having sulfonic acid groups, weakly acidic cation exchange resins having carboxylic acid groups, etc.)] and the like. These acid catalysts can be used alone or in combination of two or more kinds.

  When the reactive group is a glycidyl group, a base catalyst may be used. The base catalyst may be either an inorganic base or an organic base. Examples of the inorganic base include alkali metal hydroxides (sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonates and the like. Examples of organic bases include tertiary amines such as trialkylamines (trimethylamine, triethylamine, etc.), alkanolamines (triethanolamine, dimethylaminoethanol, etc.), heterocyclic amines (N-methylmorpholine, etc.), hexamethylenetetramine. , Diazabicycloundecene (DBU), diazabicyclononene (DBN), 1,4-diazabicyclo [2.2.2] octane (DABCO), and the like. These base catalysts can also be used alone or in combination of two or more.

  The amount of the catalyst used can be selected according to the type of the catalyst, but can be appropriately selected from the range of, for example, about 0.01 to 100 parts by mass with respect to 100 parts by mass of the unmodified cellulose nanofiber as a raw material, and is usually 0 0.01 to 20 parts by mass (eg 0.1 to 18 parts by mass), preferably 0.5 to 18 parts by mass (eg 1 to 17 parts by mass), more preferably 3 to 15 parts by mass (particularly 5 to 15 parts by mass). ) May be about.

  The reaction may be carried out in the absence of an organic solvent, but it is usually carried out in the presence of an organic solvent. The raw material cellulose nanofibers may be impregnated with this organic solvent, but the unmodified cellulose nanofibers are often reacted in a dispersion system in which they are dispersed in an organic solvent. When the unmodified cellulose nanofibers and the fluorene compound are reacted with each other in a dispersion system in which the unmodified cellulose nanofibers are dispersed in an organic solvent, a uniform reaction can be achieved. The modified cellulose nanofiber (B1) obtained by such a method has high handleability and dispersibility.

  When the raw material, unmodified cellulose nanofibers (particularly, microfibrillated fibers, nanofibers having an average fiber diameter of nanometer size) are dried, the fibers may become entangled and cannot be redispersed. Therefore, in general, unmodified cellulose nanofibers are often marketed as a water-impregnated or water-dispersed liquid. In such an aqueous dispersion, a conventional solvent substitution method for substituting water in the aqueous dispersion with an organic solvent, for example, by adding and mixing a water-soluble solvent to an aqueous dispersion of unmodified cellulose nanofibers, unmodified cellulose nanofibers A dispersion liquid in which unmodified cellulose nanofibers are dispersed in an organic solvent can be prepared by a method of repeating the operation of separating (or removing the solvent) and then adding and mixing the organic solvent. When a water-soluble organic solvent having a boiling point higher than that of water is used, the solvent can be replaced by removing water by distillation (including azeotropic distillation).

Examples of the water-soluble organic solvent include alcohols (C _1-4 alkanols such as methanol, ethanol, propanol, and isopropanol), ethers (cyclic ethers such as dioxane and tetrahydrofuran), ketones (acetone, etc.), and amides. (Dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, etc.), sulfoxides (dimethylsulfoxide, etc.), alkanediols (for example, C _2-4 alkanediols such as ethylene glycol and propylene glycol), cellosolves (methylcellosolve, Ethyl cellosolve, etc.), carbitols (ethyl carbitol, etc.), carbonates (ethylene carbonate, propylene carbonate, dimethyl carbonate, etc.), etc. And the like. These solvents may be used alone or in combination of two or more.

  In the cellulose-containing dispersion liquid that has been solvent-substituted with a water-soluble organic solvent, the water-soluble organic solvent can be replaced with a non-water-soluble organic solvent in the same manner as described above. Non-water-soluble organic solvents include ethers (dialkyl ethers such as diethyl ether and diisopropyl ether), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), ketones (methyl ethyl ketone, methyl isobutyl ketone, etc.), nitriles ( Benzonitrile), cellosolve acetates, carbitol acetates, hydrocarbons (aliphatic hydrocarbons such as hexane, octane and cyclohexane, aromatic hydrocarbons such as toluene), halogenated hydrocarbons (dichloromethane, chloroform) , Carbon tetrachloride, dichloroethane, trichloroethylene, etc.) and the like. These water-insoluble organic solvents can also be used alone or in combination of two or more.

  Of these organic solvents, aprotic solvents, particularly aprotic polar solvents (eg ethers, ketones, amides, sulfoxides, etc.) are preferable.

The solubility parameter (SP value, (cal / cm) ² ) of the organic solvent (eg, aprotic polar solvent) may be about 8 to 15 (eg, 8.5 to 15), and is usually 9 to 14.5. It may be about (for example, 10 to 14.5).

  The solid content concentration of the unmodified cellulose nanofibers in the dispersion is, for example, 0.01 to 30% by mass (e.g. 0.1 to 20% by mass), preferably 1 to 15% by mass, and more preferably 3 to 12% by mass. (For example, 5 to 10% by mass) may be sufficient. If the solid content concentration is too low, the reaction efficiency may decrease.

  The reaction may be carried out under reduced pressure, but it is usually carried out under increased pressure or normal pressure. The reaction temperature can be appropriately selected depending on the boiling point of the solvent and the like, and may be, for example, about 50 to 200 ° C (eg, 70 to 170 ° C), preferably about 80 to 150 ° C (eg, 100 to 130 ° C). The reaction may be performed under reflux of the solvent. The reaction time is not particularly limited and is, for example, about 10 minutes to 48 hours (for example, 30 minutes to 24 hours). Furthermore, the reaction can be carried out in air or in an atmosphere of an inert gas (a rare gas such as nitrogen gas or argon gas) with stirring.

  The reaction may be carried out while stirring the reaction system, and as the raw material unmodified cellulose fiber, which is not nanometer size is used, it is carried out by applying mechanical shearing force to the cellulose to make the cellulose fine. Modified cellulose nanofibers may be obtained. Further, the modified cellulose fiber may be pulverized by defibration after the reaction is completed.

  The modified cellulose nanofiber (B1) produced by the reaction may be separated and purified by a conventional method (for example, centrifugation, filtration, concentration, extraction, etc.). For example, a solvent capable of dissolving at least the fluorene compound may be added to the reaction mixture, and the unreacted fluorene compound may be removed by a separation method (conventional method) such as the centrifugation, filtration, or extraction to separate and purify. The separation operation can be performed multiple times (for example, about 2 to 5 times). Further, the modified cellulose nanofibers that have been separated and purified are dried under heating, under reduced pressure or under normal pressure to obtain a modified cellulose fiber having a powder form.

  Incidentally, the modified cellulose purified by repeatedly removing the unreacted fluorene compound by the separation method, when analyzed by a method such as Raman analysis, there is a peak derived from the cellulose and a peak derived from the fluorene compound, in the cellulose. It can be confirmed that the fluorene compound is bonded.

  On the other hand, when producing the modified cellulose nanofibers by melt-kneading in the thermoplastic resin (A), the modified cellulose nanofibers may be produced in the process of melt-kneading the resin composition, as described later.

(Characteristics of Cellulose Nanofiber (B))
The average fiber diameter of the cellulose nanofiber (B) is, for example, about 1 to 1000 nm (eg, 2 to 800 nm), preferably 3 to 500 nm (eg, 5 to 300 nm), and more preferably 10 to 200 nm (particularly 15 to 100 nm). It may be. If the average fiber diameter is too large, the properties such as strength of the resin composition may deteriorate. The maximum fiber diameter of the cellulose nanofibers is, for example, about 3 to 1000 nm (eg, 4 to 900 nm), preferably 5 to 700 nm (eg, 10 to 500 nm), and more preferably 15 to 400 nm (particularly 20 to 300 nm). Good. In many cases, the cellulose nanofibers do not substantially contain cellulose fibers having a fiber diameter of micrometer size.

  The average fiber length of the cellulose nanofiber (B) can be selected from the range of, for example, about 0.01 to 500 μm (eg, 0.1 to 400 μm), and is usually 1 μm or more (eg, 5 to 300 μm), preferably 10 μm or more (eg, 20 to 200 μm), more preferably 30 μm or more (particularly 50 to 150 μm). If the average fiber length is too short, the mechanical properties of the resin composition may deteriorate, while if it is too long, the dispersibility in the resin composition may decrease.

  The ratio (aspect ratio) of the average fiber length to the average fiber diameter of the cellulose nanofiber (B) is, for example, 5 or more (eg, about 5 to 10000), preferably 10 or more (eg, about 10 to 5000), and more preferably 20. It may be above (e.g., about 20 to 3000), particularly 50 or more (e.g., about 50 to 2000), 100 or more (e.g., about 100 to 1000), and even 200 or more (e.g., about 200 to 800). Good. If the aspect ratio is too small, the reinforcing effect on the thermoplastic resin will be reduced, and if the aspect ratio is too large, uniform dispersion will be difficult and the fibers may be easily decomposed (or damaged).

  In the present specification and claims, the average fiber diameter, the average fiber length and the aspect ratio of the cellulose nanofiber (B) are 50 fibers randomly selected from the image of the scanning electron micrograph, It may be calculated by averaging.

  In the resin composition of the present invention, when the properties (for example, low linear thermal expansion property, strength, heat resistance, etc.) of the cellulose nanofiber (B) are effectively exhibited, the cellulose nanofiber having high crystallinity is preferable. In the cellulose nanofiber (B), the crystallinity of cellulose is, for example, 40 to 100% (for example, 50 to 100%), preferably 60 to 100%, more preferably 70 to 100% (particularly 75 to 100%). The degree of crystallinity may be about 60% or more (for example, 60 to 99%). If the crystallinity is too low, the properties such as linear thermal expansion property and strength may be deteriorated. As the crystal structure of cellulose, for example, I-type, II-type, III-type, IV-type and the like can be exemplified, and the I-type crystal structure excellent in low linear expansion characteristics and elastic modulus is preferable. The crystallinity can be measured using a powder X-ray diffractometer (“Ultima IV” manufactured by Rigaku Corporation) or the like.

(Characteristics of modified cellulose nanofiber (B1))
When the cellulose nanofiber (B) is the modified cellulose nanofiber (B1), the modified cellulose nanofiber (B1) may have the following properties in addition to the above properties.

  The modified cellulose nanofiber (B1) obtained by using the catalyst usually has a powdery form and is excellent in handleability. Further, the modified cellulose nanofibers (B1) may have a powdery form even if the modification ratio (bonding amount) of the fluorene compound is relatively small.

In the modified cellulose nanofiber (B1), the ratio (modification rate) of the fluorene compound bonded to the unmodified cellulose nanofiber is 0.01 to 33% by mass (for example, 1 to 25% by mass) in the modified cellulose nanofiber (B1). %) Range can be selected. In particular, when the group X ¹ of the fluorene compound is a group — [(OA) _m1 —Y ¹ ] (in the formula, Y ¹ represents a hydroxyl group), the modification ratio (content ratio of the fluorene compound) is modified cellulose. It can be selected from the range of about 0.01 to 30% by mass in the nanofiber (B1), for example, 0.1 to 30% by mass, preferably 0.5 to 25% by mass (eg 1 to 25% by mass), and more preferably It may be about 2 to 20% by mass (particularly 3 to 20% by mass). When the group X ¹ of the fluorene compound is a group — [(OA) _m1 —Y ¹ ] (wherein Y ¹ represents a glycidyloxy group), the modification rate is about 0.01 to 33% by mass ( For example, it may be about 0.1 to 30% by mass, preferably about 1 to 25% by mass (for example, 2 to 25% by mass), and more preferably about 3 to 20% by mass (particularly 5 to 20% by mass).

  If the modification ratio is too large, the properties such as dispersibility in an aqueous solvent and the low linear thermal expansion coefficient may be deteriorated. Conversely, if it is too small, a powdery morphology cannot be formed, and the handleability tends to be deteriorated. Or the dispersibility (or miscibility) with the thermoplastic resin in the resin composition may decrease. The modification rate can be measured by the method described in Examples below.

  The modified cellulose nanofiber (B1) has a low water content, probably because the hydrophobicity is improved by the modification of the fluorene compound. That is, the water content is, for example, 0 to 7% by mass (for example, 0 to 5% by mass), preferably 0.1 to 5% by mass, when left to stand for one day under the conditions of a temperature of 25 ° C. and a humidity of 60%. Preferably, it may be about 0.3 to 3% by mass. The water content can be measured using a near infrared analyzer or the like.

  The bulk density (apparent density) of the modified cellulose nanofiber (B1) is, for example, 0.01 to 0.7 g / when measured in accordance with JIS K7365-1999 under the conditions of a temperature of 25 ° C. and a humidity of 60%. ml, preferably 0.05 to 0.5 g / ml, more preferably 0.1 to 0.3 g / ml. The bulk density P can be calculated by the formula P = W / V by inserting a modified cellulose nanofiber having a predetermined weight W into a graduated cylinder and measuring the volume V.

  The modified cellulose nanofiber (B1) has high fluidity, and the angle of repose is, for example, 20 to 45 ° when measured according to JIS R9301-2-2 under the conditions of a temperature of 25 ° C. and a humidity of 60%. It may be preferably 25 to 40 °, more preferably about 30 to 35 °. If the fluidity is too large, the handleability is lowered, and if it is too small, the dispersibility may be lowered.

  The modified cellulose nanofiber (B1) maintains the nanofiber morphology without forming a viscous liquid. Therefore, the molecular weight (or the degree of polymerization) is relatively large, and the viscosity average degree of polymerization may be, for example, 100 to 10,000, preferably 200 to 5,000, and more preferably 300 to 2,000.

  The viscosity average degree of polymerization can be measured by the viscosity method described in TAPPI T230. That is, 0.04 g of the modified cellulose nanofiber is precisely weighed, 10 mL of water and 10 mL of a 1M copper ethylenediamine aqueous solution are added, and the modified cellulose nanofiber is dissolved by stirring for about 5 minutes. The obtained solution is put into an Ubbelohde type viscosity tube, and the flow rate is measured at 25 ° C. The flow rate of a mixed solution of 10 mL of water and 10 mL of a 1 M copper ethylenediamine aqueous solution is measured as a blank. Using the intrinsic viscosity [η] calculated on the basis of these measured values, the viscosity average degree of polymerization can be calculated according to the following formula described in the Wood Science Experiment Manual (edited by the Wood Research Society of Japan, published by Bunagaido).

      Viscosity average degree of polymerization = 175 × [η].

(Ratio of the cellulose nanofiber (B))
The mass ratio of the thermoplastic resin (A) (particularly, an olefin resin such as polypropylene resin) and the cellulose nanofiber (B) is about the former / the latter = 99.9 / 0.1 to 50/50. It may be selected from the range, and may be, for example, about 99/1 to 70/30, preferably 97/3 to 75/25, and more preferably 95/5 to 80/20 (particularly 93/7 to 85/15). . If the proportion of the cellulose nanofibers (B) is too small, the mechanical properties of the resin composition may deteriorate. On the contrary, if the proportion is too large, the flexibility of the resin composition may decrease and the moldability may decrease. There is.

[Polysilane (C)]
In the resin composition of the present invention, cellulose nanofibers are added to the thermoplastic resin (A) by adding polysilane (C) to the thermoplastic resin (A) in addition to the cellulose nanofibers (B). Despite being compounded, the flexibility of the resin composition can be maintained and the moldability can be improved.

  Polysilane is not particularly limited as long as it is a chain (linear or branched), cyclic or network compound having a Si—Si bond. Polysilane usually has at least one structural unit among the structural units represented by the formulas (2) and (3). The molecular structure of polysilane is preferably linear (linear or branched) or cyclic.

In the above formulas (2) and (3), examples of the organic group represented by R ^{3 to} R ⁵ include a hydrocarbon group and an ether group corresponding to these hydrocarbon groups. Examples of the hydrocarbon group include linear groups such as alkyl groups (methyl group, ethyl group, propyl group, 2-propyl group (isopropyl group), n-butyl group, isobutyl group, pentyl group, hexyl group, or the like. Branched C _1-12 alkyl group etc.); cycloalkyl group (C _5-12 cycloalkyl group such as cyclopentyl group, cyclohexyl group, methylcyclohexyl group etc.); alkenyl group (allyl group, butenyl group, pentenyl group etc. C _2-12 alkenyl group etc.); Cycloalkenyl group (C _5-12 cycloalkenyl group such as cyclopentenyl group, cyclohexenyl group etc.); Aryl group (C ₆ such as phenyl group, tolyl group, xylyl group, naphthyl group etc. _-14 an aryl group); an aralkyl group (benzyl group, _{C 6-10} ants such as phenethyl Le etc. _{C 1-4} alkyl group). Of these hydrocarbon groups, an alkyl group and an aryl group are particularly preferable.

Examples of the ether group corresponding to these hydrocarbon groups include an alkoxy group (a C _1-12 alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group and a pentyloxy group); a cycloalkyloxy group (cyclopentyl group). An oxy group, a C _5-12 cycloalkyloxy group such as a cyclohexyloxy group); an aryloxy group (a C _6-14 aryloxy group such as a phenoxy group and a naphthyloxy group) and the like.

Of these organic groups, a hydrocarbon group is preferable, an alkyl group and an aryl group are more preferable, and a C _1-6 alkyl group and a C _6-10 aryl group are most preferable.

  Examples of the silyl group include a silyl group, a silidanyl group, a trisilanyl group, and a tetrasilanyl group.

Of these, R ^{3 to} R ⁵ may usually be an alkyl group or an aryl group. The alkyl group may be, for example, a C _1-6 alkyl group, preferably a C _1-4 alkyl group, more preferably a C _1-2 alkyl group, usually a methyl group. The aryl group is preferably a C _6-14 aryl group, more preferably a C _6-10 aryl group, and particularly preferably a phenyl group.

The combination of R ³ and R ⁴ may include at least one of an alkyl group and an aryl group, and R ¹ and R ² may be the same or different. The combination of R ³ and R ⁴ is preferably a combination of an alkyl group and an aryl group, more preferably a combination of a C _1-2 alkyl group and a C _6-10 aryl group, particularly a combination of a methyl group and a phenyl group. Is preferred.

  Specific polysilanes include linear or cyclic polysilanes having the structural unit represented by the formula (2), branched or network polysilanes having the structural unit represented by the formula (3), and the above formulas. Examples thereof include polysilane having a combination of the structural units represented by (2) and (3). These polysilanes may be used alone or in combination of two or more. The branched or network polysilane may further contain a structural unit represented by the following formula (4).

Preferred polysilanes include linear or cyclic polysilanes having the structural unit represented by the above formula (2), preferably polydialkylsilanes, polyalkylarylsilanes, polydiarylsilanes, and polysilane copolymers thereof. More preferably, linear polyalkylarylsilane, cyclic polydiarylsilane (eg, cyclic polydiphenylsilane), and particularly linear _{polyC 1-2 alkylC 6-10} arylsilane (eg, polymethylphenylsilane) is preferable. .

  The terminal structure of the polysilane (C) is not particularly limited, and examples thereof include the same organic groups (for example, an alkyl group, an alkoxy group, etc.), a hydrogen atom, a hydroxyl group and a silyl group as described above, and usually a hydrogen atom. It may be a hydroxyl group, an alkoxy group or a silyl group.

Regarding the molecular weight of the polysilane (C), for example, the weight average molecular weight is, for example, 100 to 10,000, preferably 300 to 5,000, more preferably about 500 to 3,000; the number average molecular weight is, for example, 100 to 10,000, preferably 300 to 5,000. The degree of dispersion (M _w / M _n ) may be, for example, 1 to 5, preferably 1 to 3, more preferably 1 to 2, and especially 1 to 1.5. May be. The weight average molecular weight (M _w ) and the number average molecular weight (M _n ) of polysilane can be measured by GPC in terms of polystyrene. If the polysilane (C) has a low molecular weight (for example, a weight average molecular weight of 3,000 or less), the viscosity of the thermoplastic resin (A) tends to decrease, and the effect of improving the melt fluidity of the resin composition is large. Become. From the viewpoint of compatibility with the thermoplastic resin (A), it seems that the polysilane (C) preferably has a low molecular weight.

  The average degree of polymerization of the polysilane (C) is, for example, 2 to 25, preferably 2 to 15, and more preferably 3 to 10 in terms of silicon atom (that is, the average number of silicon atoms per molecule). Good.

  The proportion of the polysilane (C) is 0.01 parts by mass or more based on 100 parts by mass of the total amount of the thermoplastic resin (A) (in particular, olefin resin such as polypropylene resin) and the cellulose nanofibers (B) ( For example, it can be selected from the range of 0.1 to 10 parts by mass), for example, 0.2 to 5 parts by mass (for example, 0.3 to 3 parts by mass), preferably 0.4 to 2 parts by mass, more preferably 0. It is about 5 to 1.5 parts by mass (particularly 0.8 to 1.2 parts by mass). If the proportion of polysilane (C) is too low, the flexibility of the resin composition may decrease.

[Other additives]
The resin composition of the present invention further contains other additives in addition to the thermoplastic resin (A) (in particular, an olefin resin such as polypropylene resin), the cellulose nanofiber (B) and polysilane (C). You can leave. As other additives, conventional additives can be used, for example, colorants (for example, dyes and pigments), conductive agents, flame retardants (phosphorus flame retardants, halogen flame retardants, inorganic flame retardants, etc.), Flame retardant aids, plasticizers, lubricants, stabilizers (eg antioxidants, UV absorbers, light stabilizers, heat stabilizers, etc.), mold release agents, antistatic agents, flow control agents, leveling agents, defoaming agents. Agents, surface modifiers, stress reducing agents, nucleating agents, crystallization accelerators, antibacterial agents, preservatives and the like. These additives can be used alone or in combination of two or more.

  The total proportion of the other additives may be 10% by mass or less (for example, about 0.01 to 10% by mass) in the resin composition, for example, 5% by mass or less, preferably 3% by mass or less, and further preferably It may be 1% by mass or less.

[Production method and characteristics of resin composition]
The resin composition of the present invention has excellent flexibility, and the breaking stress in a tensile test at 120 ° C is not particularly limited, but is, for example, 1 to 30 MPa, preferably 3 to 20 MPa, more preferably 5 to 15 MPa.

  In the present specification and claims, the fracture stress can be measured in detail by the method described in Examples below.

The resin composition of the present invention has a low coefficient of linear thermal expansion at high temperatures, and exhibits a low coefficient of linear thermal expansion even at 80 ° C or higher (for example, about 80 to 120 ° C). Specifically, the coefficient of linear thermal expansion at 120 ° C. is not particularly limited, but may be 3 × 10 ⁻⁴ / K or less, for example, 1 × 10 ^{−4 to} 2.5 × 10 ⁻⁴ / K, It is preferably 1.2 × 10 ^{−4 to} 2.3 × 10 ⁻⁴ / K, more preferably about 1.5 × 10 ⁻⁴ to 2 × 10 ⁻⁴ / K.

  In the present specification and claims, the linear thermal expansion coefficient can be measured in detail by the method described in Examples described later.

  The resin composition of the present invention is a mixing step of mixing the thermoplastic resin (A), the optionally modified cellulose nanofiber (B) and / or its raw material (cellulosic raw material), and polysilane (C). Can be prepared. The mixing method may be a conventional method such as dry mixing or melt kneading, and may be dry mixing, but the method of melt kneading is preferable from the viewpoint of simplicity and the like. The form of the obtained resin composition may be a form such as a pellet in which the thermoplastic resin (A), the cellulose nanofibers (B) and the polysilane (C) are melt-kneaded and integrated.

  The form of each component (raw material) is not particularly limited, and may be, for example, powdery or granular. In addition, in the melt-kneading, the order of adding the respective components is not particularly limited, and for example, a mixture or pellets containing the thermoplastic resin (A) and one component of the cellulosic raw material and the polysilane (C) may be powdered or granular. Alternatively, the other component in pellet form may be added and melt-kneaded. Alternatively, the cellulosic raw material may be treated with polysilane (C) in advance, or the cellulosic raw material and polysilane (C) may be mixed, and the thermoplastic resin (A) may be further added, followed by melt kneading. Further, each component may be added all at once and melt-kneaded.

  When the cellulose nanofibers (B) are the modified cellulose nanofibers (B1) in the mixing step (particularly, the mixing step of melt-kneading), the modified cellulose nanofibers (B1) include the fluorene compound as the raw material and the unmodified cellulose nanofibers (B1). Modified cellulose nanofibers may be used, and modified cellulose nanofibers (B1) may be generated by a kneading step by adding these raw materials.

  The melt-kneading method is not particularly limited as long as the thermoplastic resin (A) can be kneaded (or mixed) with the cellulose nanofibers (B) and the polysilane (C) in a molten state, and generally kneaded substantially uniformly (or Mixed).

  Examples of the melt kneading method include a conventional method, for example, a method using a single-screw or twin-screw extruder, roll kneading, a kneader, a Banbury mixer, and the like.

  The temperature in the melt-kneading is not particularly limited as long as it is equal to or higher than the melting temperature of the thermoplastic resin (A) and lower than the decomposition temperature, and can be selected from the range of 100 to 400 ° C. depending on the type of resin. In the case of an olefin resin such as a polypropylene resin, the temperature may be, for example, 100 to 300 ° C, preferably 130 to 260 ° C, more preferably 160 to 250 ° C (particularly 180 to 220 ° C).

  The kneading conditions can be appropriately selected depending on the type of melt kneading, but may be, for example, 10 to 500 rpm, preferably 20 to 100 rpm, and more preferably 30 to 80 rpm (particularly 40 to 60 rpm). .

  The melt-kneading time is not particularly limited, but may be, for example, 1 minute to 1 hour, preferably 3 to 30 minutes, more preferably 5 to 10 minutes.

  Since the resin composition is excellent in flexibility and moldability, a conventional molding method, for example, compression molding method, injection molding method, injection compression molding method, extrusion molding method, calender molding method, transfer molding method, blow molding method, It can be molded using a pressure molding method, a casting molding method, or the like.

  The shape of the obtained molded body is not particularly limited and can be selected depending on the application, and for example, one-dimensional structure (for example, linear or thread-like), two-dimensional structure (for example, film, sheet). Shape, plate shape, etc.), a three-dimensional structure [eg, block shape, rod shape, hollow shape (tubular or tube shape), etc.] and the like.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The raw materials used and the evaluation method are as follows.

(Raw materials used)
BPFG: 9,9-bis (4-glycidyloxyphenyl) fluorene polypropylene (PP): manufactured by Prime Polymer Co., Ltd., “Prime Polypro (registered trademark) F113G”, weight average molecular weight 6.0 × 10 ⁵ , melting point 160 ° C. , MFR 3.0 g / 10 min Polysilane: "Polymethylphenylsilane (OGSOL SI-10-40)" manufactured by Osaka Gas Chemicals, Inc. (weight average molecular weight: 700, number average molecular weight: 620).

(Modification rate of fluorene compound bonded to modified cellulose nanofiber)
The modification ratio of the fluorene compound (hereinafter referred to as the fluorene modification ratio) was measured by Raman analysis using a Raman microscope (HORIBA JOBIN YVON, XploRA), and the aromatic ring (1604 cm ⁻¹ ) and the endocyclic CH of cellulose (1375 cm ^{− 1} ) and the intensity ratio of the absorption band (I ₁₆₀₄ / I ₁₃₇₅ ). In the calculation, a diacetylcellulose (manufactured by Daicel Corporation) film containing a predetermined amount of a fluorene compound was prepared by a solution casting method, and a calibration curve prepared from these intensity ratios (I ₁₆₀₄ / I ₁₃₇₅ ) was used. I was there. All samples were measured three times, and the average value of the values calculated from the results was taken as the fluorene modification rate.

(Synthesis of modified cellulose nanofiber)
100 g of an aqueous dispersion of cellulose nanofibers (solid content concentration 15% by mass) was dispersed in 500 g of N, N-dimethylacetamide (DMAc) and centrifuged, and then the precipitated solid content was further dispersed in 500 g of DMAc and again. The solvent was replaced by centrifugation to obtain a mixture of cellulose nanofibers and DMAc (cellulose content of about 10% by mass). This mixture was transferred to a 1000 mL three-necked flask, DMAc 350 g, 9,9-bis (4-glycidyloxyphenyl) fluorene (BPFG) 15 g and diazabicycloundecene (DBU) 10 g were added, and the mixture was stirred at 120 ° C. for 3 hours. . The step of collecting the obtained mixed solution by centrifugation and washing with 1200 mL of DMAc was repeated 3 times to obtain a modified cellulose nanofiber (B-CNF). The modification rate of the fluorene compound was 12% by mass. In addition, the SEM photograph which observed the cellulose nanofiber derived from the plant which is the used raw material by SEM ("JSM-6510" by JEOL Ltd.) is shown in FIG.

(Tensile breaking stress and tensile breaking elongation)
A dynamic viscoelasticity measuring device (manufactured by UBM Co., Ltd., "Rheogel-E4000") was used to measure 5 times in accordance with JIS K 7161, and the average value of 5 measurements was taken as tensile breaking stress and tensile breaking, respectively. I tried to grow. Using an ISO multipurpose type B test piece, the test temperature was 120 ° C., the test speed was 0.275 mm / min, and the chuck distance was 20 mm. The tensile elongation at break represents the rate of increase in the distance between chucks at the time of break, based on the initial distance between chucks.

(Linear thermal expansion coefficient)
A sample was crushed, and a film adjusted to a thickness of 0.3 mm by a hot press was cut into 24 mm × 5 mm, and a thermomechanical analyzer (manufactured by Rigaku Co., “Thermo plus2 TMA8310”) was used to pull a static load of 49 mN in a tensile mode. The thermomechanical analysis was performed under a nitrogen atmosphere at a temperature range of 40 to 130 ° C. at a temperature rising rate of 5 ° C./min. The linear thermal expansion coefficient at 40 to 130 ° C. was calculated by dividing the obtained results by 2 ° C. and calculating the slope for each section.

(Example 1)
Using a Labo Plastomill (“50M” manufactured by Toyo Seiki Co., Ltd.), the melting temperature was adjusted to 200 ° C., 90 parts by mass of polypropylene (PP), 10 parts by mass of modified cellulose nanofiber (B-CNF), polysilane 1 The mass parts were kneaded at 20 rpm for 2 minutes and then at 50 rpm for 6 minutes. The obtained kneaded product was crushed and melted under pressureless pressure at 200 ° C. for 2 minutes, and then pressure-molded at 10 MPa for 3 minutes using a heat press machine (“MH-10” manufactured by Imoto Manufacturing Co., Ltd.), The film was maintained at 110 ° C. under the same pressure for 5 minutes to obtain a film having a thickness of 300 μm.

(Example 2)
An example except that an aqueous dispersion (solid content concentration 15% by mass) of cellulose nanofibers, which is a raw material used in the synthesis of modified cellulose nanofibers, was used as the unmodified cellulose nanofibers (CNF) instead of B-CNF. A film was obtained in the same manner as in 1.

(Comparative Example 1)
A film was obtained in the same manner as in Example 1 except that B-CNF was not used and 100 parts by mass of PP was used.

(Comparative example 2)
A film was obtained in the same manner as in Example 1 except that polysilane was not used.

(Comparative example 3)
A film was obtained in the same manner as in Example 2 except that polysilane was not used.

(Comparative example 4)
A film was obtained in the same manner as in Example 1 except that B-CNF and polysilane were not used and 100 parts by mass of PP was used.

  Table 1 shows the results of evaluation of tensile breaking stress and tensile breaking elongation of the films obtained in Examples and Comparative Examples.

  As is clear from the results in Table 1, the flexibility of the films obtained in the examples was high, while the flexibility of the films of the comparative examples was low. In addition, "NB" of tensile elongation at break indicates that no fracture occurred in the apparatus.

  Furthermore, the result of having evaluated the linear thermal expansion coefficient of Example 1 and Comparative Examples 1-2 is shown in FIG. As is clear from the results of FIG. 2, the composition constituting the film of Example 1 has a low coefficient of linear thermal expansion. Therefore, it became clear that the composition of the present invention can achieve a low linear thermal expansion coefficient while maintaining flexibility.

  Since the resin composition of the present invention is excellent in moldability, it is used in various applications, for example, automobile parts, home appliances / electric appliances parts, office equipment members, fishery materials, agricultural materials, gardening materials, civil engineering / construction. It is suitable for use as materials.

Claims (14)

  A resin composition comprising a thermoplastic resin (A), an optionally modified cellulose nanofiber (B) and a polysilane (C).   The resin composition according to claim 1, wherein the cellulose nanofiber (B) contains a modified cellulose nanofiber (B1) to which a fluorene compound having an aryl group at the 9,9 position is bonded. The resin composition according to claim 2, wherein the fluorene compound is a compound represented by the following formula (1).
(In the formula, ring Z is an arene ring, R ¹ and R ² are substituents, X ¹ is a heteroatom-containing functional group, k is an integer of 0 to 4, n is an integer of 1 or more, and p is an integer of 0 or more. Show) In the formula (1), X ¹ is a group — [(OA) _m1 —Y ¹ ] (in the formula, A is an alkylene group, Y ¹ is a hydroxyl group or a glycidyloxy group, and m1 is an integer of 0 or more). The resin composition according to claim 3.   The resin composition according to any one of claims 2 to 4, wherein the ratio of the fluorene compound is 0.01 to 33% by mass in the modified cellulose nanofiber (B1).   The resin composition according to any one of claims 1 to 5, wherein the cellulose nanofiber (B) has an average fiber diameter of 3 to 500 nm. The resin composition according to any one of claims 1 to 6, wherein the polysilane (C) has at least one structural unit among structural units represented by the following formulas (2) and (3).
(In the formula, R ^{3 to} R ⁵ are the same or different and represent a hydrogen atom, a hydroxyl group, an organic group or a silyl group.)   The resin composition according to claim 1, wherein the polysilane (C) is a polyalkylarylsilane having a weight average molecular weight of 100 to 10,000.   The resin composition according to any one of claims 1 to 8, wherein the thermoplastic resin (A) is an olefin resin.   The resin composition according to any one of claims 1 to 9, wherein the thermoplastic resin (A) is a polypropylene resin.   The resin composition according to claim 1, wherein the mass ratio of the thermoplastic resin (A) and the cellulose nanofiber (B) is former / latter = 99/1 to 70/30.   The resin according to any one of claims 1 to 11, wherein the proportion of the polysilane (C) is 0.1 to 10 parts by mass based on 100 parts by mass of the total amount of the thermoplastic resin (A) and the cellulose nanofiber (B). Composition.   The thermoplastic resin (A), the optionally modified cellulose nanofiber (B) and / or a raw material thereof, and a mixing step of mixing the polysilane (C) with each other. A method for producing a resin composition.   The production method according to claim 13, wherein in the mixing step, the thermoplastic resin (A), the optionally modified cellulose nanofiber (B) and / or its raw material, and the polysilane (C) are melt-kneaded.