JP2020041084A - Thermoplastic resin composition and its molded article, and method for producing the same - Google Patents

Abstract

To provide a resin composition in which a cellulose fiber is contained in a thermoplastic resin with high concentration, the cellulose fiber is dispersed in the thermoplastic resin, and mechanical characteristics are greatly improved.SOLUTION: A resin composition contains a fibrillated fiber comprising: a pulp fiber part which forms a stem by kneading a thermoplastic resin, a pulp and a compound having 9,9-bis(aryl) fluorene skeleton; and a fibril part extending from the surface of the pulp fiber part in a branch form. The fibrillated fiber has a weighted average fiber diameter of the fibrillated fiber is 3-20 μm, and a polydispersity indicating a ratio of the weighted average fiber diameter of the fibrillated fiber to an arithmetic average fiber diameter of the pulp fiber part is 3 or more.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin composition containing fibrillated fibers, a molded article thereof, and a method for producing these.

  Cellulose, which is a plant-derived fiber, has a small environmental load, is a sustainable resource, and has excellent properties such as high elastic modulus and strength, and low linear expansion coefficient. Therefore, in recent years, a resin composition containing cellulose as a reinforcing material for a resin material has been proposed in order to improve the mechanical properties of the resin.

  For example, JP-T-2002-527536 (Patent Document 1) describes a composite material in which cellulose pulp fibers having an alpha cellulose purity of more than 80% by weight are dispersed in a thermoplastic (for example, polyamide). It is also described that by combining a fiber with a thermoplastic as a reinforcing fiber, tensile strength, bending strength, impact strength, and the like are improved.

  However, in Patent Literature 1, when cellulose pulp fibers are granulated using a rotary knife cutter or when a pelletized fiber and a polymer are melt-mixed, fiber fragmentation occurs (the fiber length is shortened), It is stated that the reinforcing power by the fiber is reduced. Therefore, in Patent Literature 1, fragmentation of fibers is suppressed, and a sufficient reinforcing effect cannot be obtained. Further, in Patent Document 1, the dispersibility of the fibers in the polymer is insufficient.

  Japanese Patent No. 58885658 (Patent Document 2) describes a thermoplastic polyamide resin composition containing a thermoplastic polyamide resin and a cellulose fiber, and comprises a cellulose nanofiber having an average fiber diameter of 500 nm or less in the resin composition. It is described that mechanical properties and heat resistance can be improved by uniformly dispersing without agglomeration.

  However, in Patent Document 2, it is necessary to prepare cellulose fibers in advance so that the average fiber diameter is 500 nm or less. Further, in order to uniformly disperse the cellulose nanofibers in the polyamide resin, an aqueous dispersion of the cellulose fibers and the polyamide resin are used. It is necessary to go through a special and complicated production process of preparing a dispersion in which the monomer constituting the above is mixed and further performing a polymerization reaction (in situ polymerization) while maintaining the dispersion state of the dispersion. Further, in order to further improve the mechanical properties of the resin composition, it is advantageous to increase the concentration of cellulose fibers as a reinforcing material, but when the content of cellulose nanofibers is increased, the Since the fluidity is remarkably reduced, a resin composition containing cellulose nanofibers at a high concentration cannot be obtained.

  JP 2018-9095 A (Patent Document 3) describes a resin composition containing a polyamide resin, cellulose nanofibers, an amide-based solvent, and a compound having a 9,9-bis (aryl) fluorene skeleton. Have been. In Patent Document 3, when an amide-based solvent, a polyamide resin, and cellulose are kneaded, the amide-based solvent acts as a fibrillating agent for cellulose. Therefore, in the kneading process, cellulose is microfibrillated into cellulose nanofibers. It is described that a resin composition in which fibers are uniformly dispersed in a polyamide resin can be formed.

  However, even in Patent Document 3, when a high concentration of cellulose nanofiber is used, the fluidity of the resin composition is significantly reduced, so that it is not possible to obtain a resin composition in which the content of the fiber is increased and the mechanical properties are further improved. Have difficulty. Furthermore, in Patent Document 3, since an amide-based solvent is essential, there are problems in operation such as volatilization of the solvent in the production process, and a problem that coloring due to the amide-based solvent occurs in the resin composition.

JP 2002-527536 A Japanese Patent No. 58885658 JP 2018-9095 A

  Accordingly, an object of the present invention is to provide a resin composition containing a high concentration of cellulose fiber (or pulp fiber or cellulose pulp fiber) and having significantly improved mechanical properties (mechanical strength), and a molded article, and a production thereof. It is to provide a method.

  Another object of the present invention is to provide a resin composition having high fluidity (melt fluidity) even if it contains cellulose fibers at a high concentration, suitable for molding, a molded article, and a method for producing these. To provide.

  Still another object of the present invention is to easily and uniformly disperse cellulose fibers in a resin without special treatment (pretreatment, for example, conversion of cellulose fibers into nanofibers) to pulp (cellulose, raw cellulose) in advance. An object of the present invention is to provide a dispersed resin composition, a molded article, and a method for producing the same.

  Another object of the present invention is to provide a resin composition, a molded article, and a method for producing the same, which can significantly reduce coloring in the production process.

  The present inventors have conducted intensive studies to achieve the above object, and as a result, added a thermoplastic resin, pulp (raw cellulose, cellulose pulp), and a compound having a 9,9-bis (aryl) fluorene skeleton. When kneaded, the compound having a 9,9-bis (aryl) fluorene skeleton acts as a fibrillation aid, and surprisingly, the pulp is not fibrillated to cellulose nanofibers, but to a moderately fibrillated state, The present inventors have found that the fluidity (melt fluidity) is high even when the fibers are contained in the thermoplastic resin at a high concentration and the present invention has been completed.

  That is, the resin composition of the present invention is a resin composition containing a thermoplastic resin and fibrillated fibers, and further contains a compound having a 9,9-bis (aryl) fluorene skeleton, wherein the fibrillated fibers are A pulp fiber portion forming a trunk, and a fibril portion extending in a branch shape from the surface of the pulp fiber portion, wherein the weighted average fiber diameter of the fibrillated fiber is 3 to 20 μm, and the fibrillation The polydispersity represented by the ratio of the weighted average fiber diameter to the arithmetic average fiber diameter of the fibers is 3 or more. The arithmetic average fiber diameter of the fibrillated fiber may be 0.5 to 15 μm, the maximum fiber diameter of the fibrillated fiber may be 40 μm or less, and the minimum fiber diameter may be 0.01 μm or more. Further, the average aspect ratio of the pulp fiber portion may be 10 or more. The thermoplastic composition resin may include a polyamide resin. The compound having a 9,9-bisarylfluorene skeleton may be a compound represented by the following formula (1):

(Wherein, ring Z is an arene ring, X is a group represented by the following formula (2-1), (2-2), or (2-3), n is an integer of 1 to ³ , R ³ And R ⁴ represent a substituent, p represents 0 or an integer of 1 or more, and k represents an integer of 0 to 4).

(In the formula, R ¹ is a hydrogen atom or an alkyl group, R ² is an alkylene group, and m 1 and m ² each represent 0 or an integer of 1 or more.)

  In the formula (1), X may be a group represented by the formula (2-3). The proportion of the compound having a 9,9-bisarylfluorene skeleton may be 15 to 60 parts by mass with respect to 100 parts by mass of the fibrillated fiber. Further, the resin composition of the present invention may not contain an amide solvent. The resin composition of the present invention can be classified into a first resin composition useful as a masterbatch and a second resin composition suitable for molding, and the thermoplastic resin contained in the first resin composition is used as a first resin composition. The first thermoplastic resin and the thermoplastic resin that dilutes the first resin composition may be referred to as a second thermoplastic resin. The first resin composition of the present invention comprises a fibrillated fiber with respect to the total amount of a thermoplastic resin (first thermoplastic resin), a fibrillated fiber, and a compound having a 9,9-bis (aryl) fluorene skeleton. It may be contained at a ratio of 10 to 50% by mass. The second resin composition contains fibrils based on the total amount of the thermoplastic resin (the first thermoplastic resin and the second thermoplastic resin), the fibrillated fiber, and the compound having a 9,9-bis (aryl) fluorene skeleton. The modified fiber may be contained in a ratio of 1 to 30% by mass. The present invention also includes a molded article containing the resin composition (the first resin composition or the second resin composition). Furthermore, the present invention also includes a method for producing the resin composition, in which pulp, a thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton are kneaded (melt kneaded). Thereby, the resin composition of the present invention can be adjusted. Specifically, the first resin composition of the present invention is produced by kneading pulp (raw cellulose), a first thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton. And may be produced without using a solvent. The second resin composition can be adjusted by kneading the first resin composition (master batch) and the second thermoplastic resin.

  In the present specification, fibrillated fibers (pulp fibers having a fibrillated surface) are fibers in which the arithmetic average fiber diameter of the pulp fiber portion is not defibrated to nanometer size (for example, the arithmetic operation of the pulp fiber portion). The average fiber diameter means fibers having a micrometer size.

  In the present invention, since the compound having a 9,9-bis (aryl) fluorene skeleton acts as a cellulose fibrillation aid, the pulp (raw cellulose) can be easily prepared without special treatment (pretreatment). Pulp (raw material cellulose) can be defibrated appropriately, and the resulting fibrillated fibers have a fiber diameter larger than nanometer size and do not need to be converted into nanofibers, so that the fibrillated fibers can be contained in the resin at a high concentration. . Further, the fluidity of the resin composition can be improved. Therefore, the resin composition of the present invention can significantly improve the mechanical properties of the thermoplastic resin. Further, since it is not necessary to use a predetermined solvent, coloring in the manufacturing process can be significantly reduced.

FIG. 1 shows the results of observation of a pulp fiber in the master batch 1 obtained in Example 1 with a polarizing microscope. FIG. 2 is a scanning electron microscope (SEM) observation result of the pulp fibers in the master batch 1 obtained in Example 1. FIG. 3 is a result of observation of a pulp fiber in the master batch 2 obtained in Example 2 with a polarizing microscope. FIG. 4 is a scanning electron microscope (SEM) observation result of the pulp fibers in the master batch 2 obtained in Example 2. FIG. 5 shows the results of observation of the pulp fibers in the master batch 3 obtained in Comparative Example 1 with a polarizing microscope. FIG. 6 is a scanning electron microscope (SEM) observation result of the pulp fiber in the master batch 3 obtained in Comparative Example 1. FIG. 7 shows the results of observation of the pulp fibers in the master batch 4 obtained in Comparative Example 3 with a polarizing microscope. FIG. 8 is a scanning electron microscope (SEM) observation result of the pulp fibers in the master batch 4 obtained in Comparative Example 3.

[Resin composition (first resin composition)]
The first resin composition of the present invention contains a thermoplastic resin, fibrillated fibers (pulp fibers or cellulose fibers having fibrillated surfaces), and a compound having a 9,9-bis (aryl) fluorene skeleton. And a resin composition in which fibrillated fibers are dispersed in a thermoplastic resin. Further, the first resin composition of the present invention is suitable for forming a master batch (or a resin reinforcing agent).

(Thermoplastic resin)
The thermoplastic resin (first thermoplastic resin) is not particularly limited, and examples thereof include olefin-based resins (poly-α-C _2-6 olefin-based resins such as polyethylene-based resins, polypropylene-based resins, and polymethylpentene-based resins). And modified olefin resins (eg, halogenated olefin resins such as chlorinated polyethylene, graft copolymers such as maleic anhydride-grafted polyethylene), and ethylene-vinyl acetate copolymers (EVA). ), Copolymers such as ethylene-vinyl alcohol copolymers); vinyl chloride resins (polyvinyl chloride resins, polyvinylidene chloride resins, etc.); fluorine resins (polytetrafluoroethylene, etc.); vinyl acetate resins Resin (polyvinyl acetate or its derivative (polyvinyl alcohol, poly Styrene-based resin (polystyrene; styrene-based copolymer such as acrylonitrile-styrene copolymer (AS resin), impact-resistant polystyrene-based resin, rubber reinforcement such as acrylonitrile-butadiene-styrene copolymer) polystyrene resin or the like); (meth) acrylic resin (poly (meth) acrylate, etc.); polyester resins (polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, C _2-4 alkylene C such as polyethylene naphthalate C _5-10 cycloalkylene di C _1-4 alkylene C _6-12 arylates such as homo- or copolymerized polyesters having _6-12 arylate units, poly (1,4-cyclohexyl dimethylene terephthalate), polyphenylene Polyaromatic polyesters such as arylate (polyarylate), etc .; polycarbonate resins (bisphenol A type polycarbonate resin, etc.); polyamide resins (aliphatic polyamides such as polyamide 6, polyamide 66, cycloalkanedicarboxylic acid and diamine, etc.) Polyaliphatic polyamides, MXD-6, aromatic polyamides such as polyamides formed with terephthalic acid and trimethylhexamethylenediamine, etc .; polyether resins (polyphenylene ether resins, polyether ketone resins) , Polyether ether ketone resin, etc.); polyphenylene sulfide resin; polysulfone resin (polysulfone resin, polyether sulfone resin, etc.); polyacetal resin; liquid crystal plastic (liquid crystal polyester) Etc.); a thermoplastic elastomer (olefin elastomer, styrene elastomer, ester elastomer, amide elastomer, vinyl chloride elastomer, and fluorine-based elastomers) and the like. These thermoplastic resins can be used alone or in combination of two or more.

  Preferred thermoplastic resins are olefin-based resins, styrene-based resins, polyester-based resins, polycarbonate-based resins, polyamide-based resins, ester-based elastomers, amide-based elastomers, and more preferably polyester-based resins, polyamide-based resins, ester-based elastomers, and amide-based resins. From the viewpoint of high mechanical strength such as tensile strength and impact strength and high affinity with fibrillated fibers, polyamide-based resins may be used.

  Examples of the polyamide resin include a homopolyamide and a copolyamide in which a homopolyamide component is copolymerized. Examples of the homopolyamide include aliphatic polyamide resins (for example, polyamide 6, polyamide 12, polyamide 11, polyamide 46, polyamide 66, polyamide 610, polyamide 611, polyamide 612, etc.) and alicyclic polyamide resins (for example, diaminomethyl A polymer of cyclohexane and adipic acid), a semi-aromatic polyamide resin or an aromatic polyamide resin (for example, a polymer of trimethylhexamethylenediamine and terephthalic acid, a polyamide MXD (for example, a mixture of meta-xylylenediamine and adipic acid) And the like). Examples of the copolyamide include aliphatic polyamide resins such as copolyamide 6/66, copolyamide 6/11, copolyamide 6/12, and copolyamide 66/12. These polyamide resins can be used alone or in combination of two or more.

Preferred polyamide-based resins may be aliphatic polyamide resins (homopolyamides, copolyamides), and more preferably a C _6-16 alkylene group (for example, a C _6-12 alkylene group in the main chain of the polymer; Aliphatic polyamide resin having at least a hexamethylene group (for example, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 611, polyamide 612, copolyamide 6/11, copolyamide 66/12, etc.). And polyamide 6 and the like are particularly preferable.

  The polyamide resin may be crystalline or amorphous, and may be a transparent polyamide resin (amorphous transparent polyamide resin). As the polyamide-based resin, a crystalline resin is usually often used from the viewpoint of the mechanical properties of the composite (composite material or compound) and its molded product.

  The melting point of the polyamide resin is, for example, 250 ° C. or less (for example, 100 to 250 ° C.), preferably 220 ° C. or less (for example, 120 to 220 ° C.), and more preferably 200 ° C. or less (for example, about 150 to 190 ° C.). It may be.

  The weight average molecular weight (Mw) of the thermoplastic resin (for example, polyamide resin) can be selected from the range of 5,000 to 1,000,000, for example, 10,000 to 800,000 (for example, 15,000 to 100,000), preferably 20,000 to 600,000 (for example, 23000 to 100,000). 70,000), and more preferably about 25,000 to 500,000 (e.g., 30,000 to 50,000). The dispersity (Mw / Mn) may be, for example, 1 to 5, preferably 1 to 3, more preferably 1 to 2, and especially 1 to 1.5. The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin can be measured by gel permeation chromatography (GPC) in terms of polystyrene.

(Fibrillated fiber)
The fibrillated fiber (pulp fiber having a fibrillated surface) is a defibrated fiber derived from pulp (raw material cellulose or cellulose), and a pulp fiber portion (trunk fiber portion, fiber body) forming a trunk portion in the fibrillated fiber. And a large diameter portion) and a fibril portion (branched fiber portion) extending in a branch shape from the surface of the pulp fiber portion, and are dispersed in the resin composition.

  In addition, even if the fibrillated fiber is a modified fiber (or a modified fiber) in which at least a part of the functional group or the reactive group (for example, a hydroxyl group or the like) has been subjected to a modification treatment (for example, acylation, etherification, or the like). It may be an unmodified fiber that has not been subjected to a modification treatment.

  The modifier may have, for example, a functional group capable of binding (reacting) with a hydroxyl group of the cellulose fiber (eg, an epoxy group, a carboxyl group, or the like), a cationic group such as ammonium, phosphonium, or sulfonium, or It may have an anionic group such as a carboxyl group, a phosphoric acid group and a sulfonic acid group.

  The ratio of the modifier is, for example, 1 part by mass or less (for example, 0.9 part by mass or less), preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less based on 100 parts by mass of the cellulose fiber. It may be.

  From the viewpoint of not impairing the hydrogen bonding property with a thermoplastic resin (for example, a polyamide-based resin), the lower the amount of modification, the better. For example, the modification ratio is 10% by mass or less (for example, 0.01 to 10% by mass). , Preferably 5% by mass or less, more preferably 1% by mass or less. The fibrillated fiber of the present invention can be uniformly dispersed in a thermoplastic resin (for example, a polyamide-based resin) without being subjected to a modification treatment, and thus is generally an unmodified fiber that has not been subjected to a modification treatment.

  Examples of the pulp (raw cellulose, cellulose) include pulp having a low content of non-cellulose components such as lignin and hemicellulose, such as pulp derived from plants, pulp derived from animals, and pulp derived from bacteria. Examples of plant-derived pulp include wood pulp such as conifers (pine, fir, spruce, hemlock, cedar, etc.) and hardwoods (beech, hippo, poplar, maple, etc.); hemp (hemp, flax, manila hemp, ramie, etc.) ), Straw, bagasse, mitsumata, bamboo, sugarcane and other plant pulp; cotton linters, bombax cotton, kapok and other seed wool fiber pulp; and animal-derived pulp derived from bacteria such as ascid cellulose. Examples of pulp include cellulose contained in nata de coco. These pulp (cellulose) can be used alone or in combination of two or more. Among these pulp (or cellulose), it is preferable to use a plant-derived cellulose raw material, such as wood pulp (for example, softwood pulp, hardwood pulp, etc.) and seed wool fiber-derived pulp (for example, cotton linter pulp). And the like. The pulp may be a mechanical pulp obtained by mechanically treating a pulp material, but is preferably a chemical pulp obtained by chemically treating a pulp material because of its low content of non-cellulose components.

  The pulp or cellulose (raw material cellulose) preferably has high crystallinity, and the degree of crystallinity of the pulp (cellulose) is, for example, 40 to 100% (for example, 50 to 100%), preferably 60 to 95%. More preferably, it may be about 70 to 90% (particularly 75 to 90%), and usually, the crystallinity may be 60% or more. In addition, the crystallinity of pulp (cellulose) can be measured by an X-ray diffraction method. In addition, examples of the crystal structure of pulp (cellulose) include I-type, II-type, III-type, and IV-type, and an I-type crystal structure excellent in elastic modulus and the like is preferable.

  In the present invention, the fibrillated fiber is a cellulose fiber having a finer (or fibrillated) fiber surface of pulp (raw cellulose such as cellulose or cellulose pulp or cellulose fiber having an average fiber diameter of 10 μm or more). (Pulp fiber part).

  The average fiber diameter (arithmetic mean fiber diameter) D1 of the pulp fiber portion is, for example, 1 to 100 μm (for example, 2 to 80 μm), preferably 5 to 50 μm (for example, 10 to 40 μm), and more preferably 15 to 30 μm (for example, 18 to 23 μm).

  The average fiber length L of the pulp fiber portion can be selected, for example, from the range of 10 to 6000 μm, and may be, for example, 50 to 3000 μm (for example, 100 to 1000 μm), and preferably 150 to 800 μm (for example, 180 to 500 μm). ), And more preferably 200 to 400 μm (for example, 250 to 300 μm).

  The average aspect ratio (L / D1) of the pulp fiber portion of the fibrillated fiber can be usually selected from a range of about 4 to 1000, for example, 5 or more (for example, about 5 to 100), and preferably 8 or more (for example, 8 or more). To about 50), more preferably 10 or more (for example, about 10 to 30, especially about 10 to 15). If the average aspect ratio is too small, the reinforcing property of the resin may be reduced.

  The average fiber diameter D1 and the average fiber length L are determined by using a solvent to obtain a fibrillated fiber in a resin composition containing a fibrillated fiber, a thermoplastic resin, and a compound having a 9,9-bis (aryl) fluorene skeleton. The other components were eluted to prepare a dispersion of fibrillated fibers having a solid content of 0.3 to 1% by mass. Observation of the dispersion by a polarizing microscope (magnification: 20 to 50 times) showed that n points (n: 20 The following pulp fiber parts (at least the above integers) are randomly selected, and the following formulas (1) and (1) are used by using the selected n-point fiber diameter (D1i) and fiber length (Li) (i = 1 to n). It can be calculated by 2). Specifically, it can be measured by the method described in Examples.

  The average aspect ratio can be calculated from the ratio of the average fiber diameter L to the average fiber diameter D1 (L / D1).

  The arithmetic average fiber diameter D2 (the arithmetic average fiber diameter including the pulp fiber portion and the fibril portion) of the fibrillated fiber (pulp fiber having a fibrillated surface) is, for example, 0.5 to 15 μm (for example, 0.7 to 0.7 μm). 10 μm), preferably about 0.8 to 5 μm (eg, 1 to 3 μm), and more preferably about 1.2 to 2.5 μm (eg, 1.5 to 2 μm).

  The maximum fiber diameter D3 of the fibrillated fiber may be, for example, 40 μm or less (for example, 10 to 40 μm), preferably 35 μm or less (for example, 15 to 35 μm), and more preferably 30 μm or less (for example, 18 to 30 μm). ). If the maximum fiber diameter is too large, dispersion may be poor.

  The minimum fiber diameter (D4) of the fibrillated fiber may be, for example, 0.01 μm or more (for example, 0.05 to 5 μm), and preferably 0.08 μm or more (for example, 0.1 to 1 μm). More preferably, it may be 0.15 μm or more (for example, 0.2 to 0.4 μm). If the minimum fiber diameter is too small, the melt fluidity may decrease.

  As described above, the fibrillated fiber contained in the resin composition of the present invention is characterized in that it is fibrillated and has a fibril portion having a small average fiber diameter and a pulp fiber portion having a large average fiber diameter. Therefore, the weighted average fiber diameter of the fibrillated fibers is usually larger than the arithmetic average fiber diameter. The weighted average fiber diameter D5 of the fibrillated fibers is, for example, 3 to 20 μm (for example, 3.5 to 20 μm), preferably 4 to 18 μm (for example, 4.5 to 16 μm), and more preferably 5 to 14 μm (for example, 5.5 to 12 μm). If the weighted average fiber diameter is too large, the aspect ratio may be reduced and high mechanical properties may not be obtained. If it is too small, the melt fluidity may be reduced.

  In addition, each fiber diameter (D2-D5) of the fibrillated fiber is other than the fibrillated fiber in the resin composition containing a fibrillated fiber, a thermoplastic resin, and a compound having a 9,9-bis (aryl) fluorene skeleton. The components are selectively eluted in a soluble solvent to remove components other than the fibrillated fibers, and the fibers provided with the pulp fiber portion and the fibril portion are observed with a scanning electron microscope (magnification: 1000 times). And a fibril portion are randomly selected in total at m points (m is an integer of 20 or more), and determined using the fiber diameter (D2j, j = 1 to m) at the selected m points. The pulp fiber portion and the fibril portion of the fibrillated fiber will be described with reference to, for example, FIG. 2 of Example 1. The fiber diameter of the pulp fiber portion can be a length indicated by a double-headed arrow. May be each fiber of a plurality of fibers in a circle. The arithmetic average fiber diameter D2 can be calculated by the arithmetic average of the fiber diameters D2j represented by the following formula (3). The largest fiber diameter among the fiber diameters D2j is the maximum fiber diameter D3, and the smallest fiber diameter is the minimum fiber diameter. The diameter can be D4. Further, the weighted average fiber diameter D5 can be calculated by the following equation (4). Specifically, it can be measured by the method described in Examples.

  The polydispersity (D5 / D2) of the fiber diameter of the fibrillated fiber may be, for example, 3 or more (for example, 3 to 20), preferably 3.5 or more (for example, 3.5 to 10), More preferably, it may be 4 or more (for example, 4 to 8), particularly 4.5 or more (for example, 4.5 to 8). If the polydispersity is too small (close to monodispersity), the dispersibility may decrease, or the fluidity may decrease. The polydispersity of the fibrillated fiber can be calculated from the ratio of the weighted average fiber diameter D5 to the arithmetic average fiber diameter D2. Specifically, it can be measured by the method described in Examples.

  In the present invention, even if the fibrillated fiber is at a high concentration, a decrease in the fluidity of the resin composition can be suppressed. The ratio (content) of the fibrillated fiber is, for example, 10 to 10% with respect to the total amount of the thermoplastic resin, the fibrillated fiber, and the compound having the 9,9-bis (aryl) fluorene skeleton in the first resin composition. It may be 50% by mass, preferably 20 to 45% by mass, more preferably 25 to 40% by mass (for example, 28 to 35% by mass). If the proportion of the fibrillated fiber is too small, the reinforcing effect may be reduced. If the proportion of the fibrillated fiber is too large, the fluidity may be reduced.

  In addition, the ratio of the fibrillated fiber may be, for example, 10 to 100 parts by mass with respect to 100 parts by mass of the thermoplastic resin (first thermoplastic resin) in the first resin composition, and is preferably It may be 20 to 80 parts by mass, more preferably 40 to 70 parts by mass. If the proportion of the fibrillated fibers is too small, defibration of the pulp is difficult to proceed, and the average fiber diameter may be excessively large.If the proportion of the fibrillated fibers is too large, the pulp fibers are cut, The aspect ratio tends to decrease, and fibrillated fibers are strongly agglomerated through hydrogen bonds, and dispersibility decreases.

  In addition, the resin composition may include cellulose nanofibers (cellulose nanofibers) in which the fiber diameter of pulp fibers has been defibrated (nanofibrillated) to a nanometer size. The number ratio of the fibrillated fiber and the cellulose nanofiber is, for example, 0 to 50 (for example, 0.01 to 30), preferably 0 to 20 (for example, 0.01 to 15) with respect to the fibrillated fiber 100. More preferably, it may be about 0 to 10 (e.g., 0.01 to 5), and usually, it is preferable not to contain cellulose nanofibers.

(Compound having 9,9-bis (aryl) fluorene skeleton)
The resin composition of the present invention has a 9,9-bis (aryl) fluorene skeleton as a fibrillation aid for relaxing pulp into an appropriate fibrillated state by relaxing hydrogen bonds acting between pulp fibers. (Fluorene compounds).

The fluorene compound (compound having a 9,9-bis (aryl) fluorene skeleton) has a 9,9-bis (aryl) fluorene skeleton and is selected from a carboxyl group or a reactive derivative thereof, an epoxy group, and a hydroxyl group. And at least one reactive group. Examples of the reactive derivative of the carboxyl group include an alkoxycarbonyl group (a _C1-4 alkoxy-carbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group), an acid halide group (a haloformyl group such as an acid chloride group and an acid bromide group). And the like. The epoxy group may be a glycidyl group as long as it contains an oxirane ring.

  A typical fluorene compound is represented by the following formula (1).

[Wherein, ring Z is an arene ring, X is a group represented by the following formula (2-1), (2-2), or (2-3), n is an integer of 1 to ³ , R ³ And R ⁴ represent a substituent, p represents 0 or an integer of 1 or more, and k represents an integer of 0 to 4].

(In the formula, R ¹ is a hydrogen atom or an alkyl group, R ² is an alkylene group, and m 1 and m ² each represent 0 or an integer of 1 or more.)

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

Examples of the condensed polycyclic arene ring, for example, fused bicyclic arene (e.g., fused bicyclic C _10-16 arene such as naphthalene) ring, fused tricyclic arenes (e.g., anthracene, phenanthrene), such as rings Examples thereof include fused bi- to tetracyclic arene rings. Preferred fused polycyclic arene rings include a naphthalene ring and an anthracene ring, and a naphthalene ring is particularly preferred. The two rings Z may be the same or different rings.

As the ring-assembled arene ring, a bi-arene ring, for example, a bi-C _6-12 arene ring such as a biphenyl ring, a binaphthyl ring, a phenylnaphthalene ring (1-phenylnaphthalene ring, 2-phenylnaphthalene ring, etc.), a terarene ring, for example, Examples thereof include a Ter C _6-12 arene ring such as a terphenylene ring. Preferred ring-assembled arene rings include bi-C _6-10 arene rings, particularly biphenyl rings.

A preferred arene ring may be a C _6-14 arene ring, more preferably a C _6-10 arene ring, especially a benzene ring or a naphthalene ring.

In the formula (1), examples of the alkyl group represented by R ¹ include a linear or branched C _1-6 such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group. An alkyl group can be exemplified. Preferred alkyl groups are _C1-4 alkyl groups, especially _C1-2 alkyl groups. m1 may be 0 or an integer of 1 or more (for example, about 1 to 6, preferably 1 to 4, and more preferably about 1 to 2). m1 may be usually 0 or 1-2.

The alkylene group R ² includes a linear or branched alkylene group, and examples of the linear alkylene group include C _2-6 alkylene groups such as an ethylene group, a trimethylene group, and a tetramethylene group (preferably, linear _{C 2-4} alkylene group, more preferably be exemplified straight chain _{C 2-3} alkylene group, especially ethylene group), a branched chain alkylene group, for example, propylene, 1,2-butanediyl group And 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).

The number m2 of the oxyalkylene group (OR ² ) can be selected from a range of about 0 or an integer of 1 or more (eg, 0 to 15, preferably 0 to 10), for example, 0 to 8 (eg, 1 to 8), preferably It may be about 0 to 5 (for example, 1 to 5), more preferably about 0 to 4 (for example, 1 to 4), particularly about 0 to 3 (for example, 1 to 3), and usually 0 to 2 (for example, 0 or 1). It may be. In the case m2 is 2 or more, kinds of the alkylene group R ² may be the same or different. In addition, the types of the substituents R ² may be the same or different in the same or different rings Z.

  In the formula (1), the number of substitutions n of the group X may be the same or different and is an integer of 1 or more, depending on the type of the ring Z, and is, for example, 1 to 4, preferably 1 to 3, and more preferably It may be 1 or 2, especially 1. The number of substitutions n may be the same or different in each ring Z.

  The group X can be substituted at an appropriate position on the ring Z. For example, when the ring Z is a benzene ring, the 2-, 3-, and 4-positions of the phenyl group (particularly, the 3-position and / or 4-position), and when ring Z is a naphthalene ring, it is often at the 5- to 8-position of the naphthyl group. For example, the naphthalene ring is located at the 9-position of fluorene. Is substituted at the 1-position or 2-position (substituted in the relation of 1-naphthyl or 2-naphthyl), and this substitution position is related to the 1,5-position, 2,6-position and the like (particularly n Is 1, the group X is often substituted in the 2,6-position relationship). When the number of substitutions 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 is not particularly limited. For example, even if the substitution is performed on an arene ring bonded to the 9-position of fluorene and / or an arene ring adjacent to the arene ring. Good. For example, the 3-position or 4-position of the biphenyl ring may be bonded to the 9-position of fluorene, and when the 3-position of the biphenyl ring is bonded to the 9-position of fluorene, the substitution position of the carbonyl group is For example, the biphenyl ring may be at any of the 2-, 4-, 5-, 6-, 2'-, 3'-, and 4'-positions, and preferably the 6-position. Or at any of the 4′-positions (particularly at the 6-position). When the 4-position of the biphenyl ring is bonded to the 9-position of fluorene, the substitution position of the carbonyl group is 2-position, 3-position, 2'-position, 3'-position, 4'-position of the biphenyl ring. It may be at any position of the position, preferably at any of the 2-position and 4'-position (particularly at the 2-position).

In the formula (1), as the substituent R ³ , a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (methyl group, ethyl group, propyl group, isopropyl group, butyl group, A linear or branched C _1-10 alkyl group such as an s-butyl group and a t-butyl group, preferably a linear or branched C _1-6 alkyl group, more preferably a linear or branched chain Jo like C _1-4 alkyl group), a cycloalkyl group (such as C _5-10 cycloalkyl group such as cyclopentyl group, cyclohexyl group), an aryl group [phenyl group, alkylphenyl group (methylphenyl group (tolyl group) , dimethyl phenyl group (xylyl)), biphenyl group, _{C 6-12} aryl group such as a naphthyl group, an aralkyl group (a benzyl group and a phenethyl group Such as C _6-10 aryl _{-C 1-4} alkyl group), an alkoxy group (e.g., methoxy group, an ethoxy group, a propoxy group, n- butoxy group, isobutoxy group, a linear or branched such as t- butoxy A C _1-10 alkoxy group, a cycloalkoxy group (eg, a C _5-10 cycloalkyloxy group such as a cyclohexyloxy group), an aryloxy group (eg, a C _6-10 aryloxy group such as a phenoxy group, etc.) ), An aralkyloxy group (eg, a C _6-10 aryl-C _1-4 alkyloxy group such as a benzyloxy group), an alkylthio group (eg, a methylthio group, an ethylthio group, a propylthio group, an n-butylthio group, a t- A C _1-10 alkylthio group such as a butylthio group, a cycloalkylthio group (eg, A C _5-10 cycloalkylthio group such as a xylthio 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-C such as a benzylthio group). _An acyl group (eg, a C _1-6 acyl group such as an acetyl group), a nitro group, a cyano group, a dialkylamino group (eg, a di C _1-4 alkylamino group such as a dimethylamino group). Group), a dialkylcarbonylamino group (for example, a di (C _1-4 alkyl-carbonyl) amino group such as a diacetylamino group) and the like.

Of these substituents R ³ , typically, a halogen atom, a hydrocarbon group (such as an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group), an alkoxy group, an acyl group, a nitro group, a cyano group, and a substituted amino And the like. Preferred substituents R ^3, an alkyl group (methyl group, e.g., a straight chain or branched chain C _1-4 alkyl group such as ethyl group), linear or branched C _1, such as alkoxy groups (methoxy _-4 alkoxy group), particularly an alkyl group (particularly, a linear or branched _C1-3 alkyl group such as a methyl group). When the substituent R ³ is an aryl group, the substituent R ³ may form the above-mentioned ring-assembled arene ring together with the ring Z. The types of the substituents R ³ may be the same or different in the same or different rings Z.

Coefficient p of the substituents ^{R 3} can be appropriately selected depending on the type of ring Z, for example, it may be an integer of about 0-8, an integer of 0 to 4, preferably 0-3 (e.g., 0 To 2), particularly 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 ³ may be a methyl group.

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

Among these substituents R ⁴ , a linear or branched C _1-4 alkyl group (particularly, a C _1-3 alkyl group such as a methyl group), a carboxyl group or a C _1-2 alkoxy-carbonyl group, a cyano group Groups and halogen atoms are preferred. The number of substitutions 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), particularly 0. Note that the number of substitutions k may be the same or different from each other, and when k is 2 or more, the types of the substituents R ⁴ may be the same or different from each other, and are substituted with two benzene rings of a fluorene ring. the kind of the substituent R ⁴ may be the same or different. The substitution position of the substituent R ⁴ is not particularly limited, for example, a fluorene ring 2-position or 7-position (2-position, 3-position and / or 7-position, etc.).

Specific fluorene compounds having a group X represented by the formula (2-1) include 9,9-bis (carboxyaryl) fluorene in which n = 1, p = k = 0, and m1 = 0, for example, 9,9-bis (3-carboxyphenyl) fluorene, 9,9-bis (4-carboxyphenyl) fluorene, 9,9-bis (5-carboxy-1-naphthyl) fluorene, 9,9-bis (6- 9,9-bis (carboxyC _6-10 aryl) fluorene such as carboxy-2-naphthyl) fluorene; 9,9-bis (carboxyalkyl-n, wherein n = 1, p = k = 0, m1 = 1 to 3; Aryl) fluorene compounds, for example, 9,9-bis (4- (carboxymethyl) phenyl) fluorene, 9,9-bis (4- (2-carboxyethyl) phenyl) fluorene, 9,9 -Bis (3- (carboxymethyl) phenyl) fluorene, 9,9-bis (5- (carboxymethyl) -1-naphthyl) fluorene, 9,9-bis (6- (carboxymethyl) -1-naphthyl) fluorene And 9,9-bis (carboxy C _1-6 alkyl C _6-10 aryl) fluorene. These fluorene compounds can be used alone or in combination of two or more.

Specific examples of the fluorene compound having the epoxy group-containing group X represented by the formula (2-2) include 9,9-bis (glycidyloxyaryl) in which n = 1, p = k = 0, and m2 = 0. 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 C _6-10 aryl) fluorene such as, 9,9-bis (6-glycidyloxy-2-naphthyl) fluorene; n = 1, p = k = 0, m2 = 1 to 5 9,9-bis (glycidyloxy (poly) alkoxyaryl) fluorene, for example, 9,9-bis (4- (2-glycidyloxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-glycidyloxypropoxy) phenyl) fluorene, 9,9-bis (5- (2-glycidyloxyethoxy) -1-naphthyl) fluorene, 9,9-bis (6- ( 2-glycidyloxyethoxy) -2-naphthyl) fluorene such as 9,9-bis (glycidyloxy _{(poly) C 2-4} alkoxy _{C 6-10} aryl) fluorene; n = 1, p = 1 , k = 0, 9,9-bis (alkyl-glycidyloxyaryl) fluorene wherein m2 = 0, for example, 9,9-bis ( _C1-4 ) such as 9,9-bis (3-methyl-4-glycidyloxyphenyl) fluorene. Alkyl-glycidyloxy C _6-10 aryl) fluorene; 9,9-bis (alkyl-glycidyloxy) wherein n = 1, p = 1, k = 0, m2 = 1 to 5 (Poly) alkoxyaryl) fluorenes such as 9,9-bis (C _1-4 alkyl-glycidyloxy (poly) such as 9,9-bis (3-methyl-4- (2-glycidyloxyethoxy) phenyl) fluorene ) _{C 2-4} alkoxy _{C 6-10} aryl) fluorene; n = 1, p = 1 , k = 0, m2 = is 0 9,9-bis (aryl - glycidyloxy aryl) fluorene, for example, 9,9 - bis (3-phenyl-4-glycidyl oxyphenyl) fluorene such as 9,9-bis _{(C 6-10} aryl - glycidyloxy _{C 6-10} aryl) fluorene; n = 1, p = 1 , k = 0, 9,9-bis (aryl-glycidyloxy (poly) alkoxyaryl) fluorene wherein m2 = 1 to 5, for example, 9,9-bis (3-phenyl- - (2-glycidyloxyethoxy) phenyl) fluorene such as 9,9-bis _{(C 6-10} aryl - glycidyloxy _{(poly) C 2-4} alkoxy _{C 6-10} aryl) fluorene; n = 2, p = 0 , K = 0, m2 = 0, 9,9-bis (di (glycidyloxy) aryl) fluorene such as 9,9-bis (3,4-di (glycidyloxy) phenyl) fluorene -Bis (di (glycidyloxy) C _6-10 aryl) fluorene; 9,9-bis (di (glycidyloxy (poly) alkoxy) wherein n = 2, p = 0, k = 0, m2 = 1 to 5 aryl) fluorene, e.g., 9,9-bis (3,4-di (2-glycidyloxy) phenyl) fluorene such as 9,9-bis (di (glycidyloxy (poly) C Etc. _{-4 alkoxy) C 6-10} aryl) fluorene can be exemplified. These fluorene compounds can be used alone or in combination of two or more.

  The fluorene compound having the epoxy-containing group X represented by the formula (2-2) may be a monomer or a multimer (for example, a dimer, a trimer, or the like). Although good, it is preferable not to contain a multimer from the viewpoint of sufficiently suppressing yellowing (coloring). Usually, the fluorene compound having a glycidyl group often contains at least a monomer, and may be, for example, a mixture of a monomer, a dimer and a trimer.

  As a specific fluorene compound having a hydroxyl-containing group X represented by the formula (2-3), the fluorene compound having a group X represented by the formula (2-2) may be a compound having a glycidyloxy group having a hydroxyl group. Compounds substituted for the groups can be exemplified, and these compounds can be used alone or in combination of two or more.

Among these fluorene compounds, preferred fluorene compounds include, for example, 9,9-bis (glycidyloxy C _6-10 aryl) fluorene and 9,9-bis (glycidyloxy (poly) C _2-4 alkoxy C _{6- 10} aryl) fluorene, 9,9-bis (C _1-4 alkyl-glycidyloxyC _6-10 aryl) fluorene, 9,9-bis (C _1-4 alkyl-glycidyloxy (poly) C _2-4 alkoxy C _6-10 aryl) fluorene, 9,9-bis (C _6-10 aryl-glycidyloxyC _6-10 aryl) fluorene, 9,9-bis (C _6-10 aryl-glycidyloxy (poly) C _2-4 alkoxy _{C 6-10} aryl) fluorene, 9,9-bis (di _{(glycidyloxy) C 6-10} aryl) Fluorene, 9,9-bis (di (glycidyloxy _{(poly) C 2-4 alkoxy) C 6-10} aryl) single of the formula such as fluorene fluorene compound having a glycidyl group represented by (2-2) 9,9-bis (hydroxy C _6-10 aryl) fluorene, 9,9-bis (hydroxy (poly) C _2-4 alkoxy C _{6- 10} aryl) fluorene, 9,9-bis _{(C 1-4} alkyl - hydroxy _{C 6-10} aryl) fluorene, 9,9-bis _{(C 1-4} alkyl - hydroxy _{(poly) C 2-4} alkoxy _{C 6- 10} aryl) fluorene, 9,9-bis _{(C 6-10} aryl - hydroxy _{C 6-10} aryl) fluorene, 9,9-bis _{(C 6-10} aryl - hydroxy (po ) _{C 2-4} alkoxy _{C 6-10} aryl) fluorene, 9,9-bis (dihydroxy _{C 6-10} aryl) fluorene, 9,9-bis (dihydroxy _{(poly) C 2-4 alkoxy) C 6-10} aryl ) A fluorene compound having a hydroxyl group represented by the above formula (2-3) such as fluorene can be exemplified, and more preferably, from the viewpoint of compatibility with a thermoplastic resin, heat resistance, and suppression of coloring, the above formula ( A fluorene compound having a hydroxyl group represented by 2-3) may be used. In particular, 9,9-bis (hydroxy) such as 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (BPEF) may be used. _{(poly) C 2-4} alkoxy _{C 6-10} aryl) may be fluorene. In addition, "(poly) _C2-4 alkoxy" means that the number m2 of repeating _C2-4 alkoxy groups is an integer of 1 or more.

  In the present invention, the fluorene compound also acts as a modifier or an additive of the resin composition, can improve the dispersibility (or affinity) of the fibrillated fiber in the resin composition, and can improve the mechanical strength. . In particular, a fluorene compound having an epoxy group (glycidyloxy group) represented by the formula (2-2) is advantageous because the toughness can be sufficiently improved. On the other hand, if it is a fluorene compound having a group X represented by the formula (2-1) or (2-3) (particularly a fluorene compound having a hydroxyl group represented by the formula (2-3)), the mechanical strength is high. It is possible to suppress the rise of the viscosity of the resin composition (because it can improve the melt fluidity), probably because it can improve the properties of the resin composition and also act as a plasticizer. Therefore, even if the fibrillated fiber is contained at a high concentration, the decrease in the melt fluidity of the resin composition can be suppressed, and the mechanical strength (eg, strength, toughness, rigidity, etc.) and heat resistance of the thermoplastic resin can be significantly improved. it can. In addition, there is no need to increase the preparation temperature (kneading temperature) for preparing the resin composition, because the fluorene compound does not cause coloring of the resin composition and the fluorene compound also functions as a plasticizer. Can be suppressed. Therefore, coloring can be significantly suppressed in the manufacturing process.

  The resin composition only needs to substantially contain a fluorene compound, and a form in which the fluorene compound and the fibrillated fiber are bonded (for example, an ether bond, an ester bond, or the like) (the fibrillated fiber is an ether bond, an ester bond, or the like) Modified by a fluorene compound bound by a) or a free form that is not bound or modified.

  The ratio of the fluorene compound can be selected from a range of, for example, 1 to 100 parts by mass (for example, 5 to 80 parts by mass) with respect to 100 parts by mass of the fibrillated fiber, and for example, 10 to 70 parts by mass (for example, 15 to 70 parts by mass). 60 parts by mass), preferably about 25 to 50 parts by mass, and more preferably about 28 to 45 parts by mass (e.g., 30 to 40 parts by mass). If the proportion of the fluorene compound is too small relative to the fibrillated fiber, the action (effect) as a fibrillation aid is insufficient, the fibrillated fiber is not sufficiently fibrillated, and the fluidity of the obtained resin composition is reduced. When there is a possibility that the amount of the fluorene compound is too large, the melt viscosity of the resin composition is significantly reduced, the fibrillated fibers are not sufficiently defibrated, and the ratio of the low molecular weight compound of the resin composition is increased. There is a possibility that the physical properties of this may be reduced.

  Further, the proportion of the fluorene compound is 1 to 50 parts by mass, preferably 5 to 40 parts by mass (for example, 10 to 30 parts by mass), more preferably 100 parts by mass of the thermoplastic resin (first thermoplastic resin). It may be about 12 to 27 parts by mass (for example, 15 to 25 parts by mass). If the proportion of the fluorene compound is too small relative to the thermoplastic resin, the fluidity of the resin composition may be reduced or coloring (coloring due to heat history) may occur in the production process.

  Further, the ratio of the fluorene compound may be, for example, 1 to 30% by mass relative to the total amount of the thermoplastic resin, the fibrillated fiber, and the compound having the 9,9-bis (aryl) fluorene skeleton, and is preferably It may be about 5 to 20% by mass, more preferably about 8 to 16% by mass (e.g., 9 to 14% by mass). If the proportion of the fluorene compound is too small, the effect of dispersing the pulp fibers in the resin composition by the fluorene compound may be reduced, and if the proportion of the fluorene compound is too large, the mechanical properties of the molded resin composition and the molded article May decrease.

(solvent)
The resin composition of the present invention, if necessary, may contain a solvent.However, in order to appropriately defibrate the pulp fiber and suppress coloring by the solvent, and to improve the working environment, a solvent is used. It is preferable not to include it. In addition, when a solvent is contained, a process for removing the solvent is required in the manufacturing process, and there is a possibility that the working environment such as evaporation of the solvent may be harmed. For example, if the solvent is an amide (amide-based solvent) that acts as a pulp defibrating agent, pulp defibration proceeds excessively (for example, defibration to nanometer size), and the melt fluidity is significantly reduced. Further, coloring derived from the amide solvent may occur.

[Production method of resin composition (first resin composition)]
The first resin composition (master batch, kneading composition) of the present invention can be obtained by subjecting pulp (raw cellulose) to pulp, thermoplastic resin, It can be produced by kneading a compound having a bisarylfluorene skeleton. In this method, a compound having a 9,9-bisarylfluorene skeleton acts as a fibrillation aid, pulp is defibrated to an appropriate defibrated state (pulp fibers having fibrillated surface), Disperse in. Therefore, it is not necessary to subject the pulp (raw cellulose) to a fine treatment or to modify the hydroxyl groups on the surface of the cellulose in advance, and to prepare a fibrillated fiber dispersion (slurry) and fibrillate. It is not necessary to prepare an emulsion of fibers and resin, and the resin composition can be easily prepared by a one-stage operation of kneading.

  Also, because the compound having the 9,9-bisarylfluorene skeleton also acts as a plasticizer, there is no need to increase the preparation temperature (kneading temperature) for preparing the resin composition, and the heat history in the production process is reduced. The accompanying coloring can also be suppressed.

  As pulp (raw cellulose), pulp (cellulose, raw cellulose or cellulose fiber) exemplified in the section of fibrillated fiber can be used. The average fiber diameter of the pulp (raw cellulose) can be selected according to the type, for example, 10 μm to 100 mm, preferably 15 to 80 μm (eg, 18 to 60 μm), more preferably 19 to 40 μm (particularly, 20 to 30 μm). ). The average fiber length of the pulp is, for example, about 0.1 to 30 mm, preferably about 0.5 to 25 mm (for example, 0.5 to 20 mm), and more preferably about 1 to 10 mm (particularly, about 1 to 5 mm). You may. The average fiber diameter and average fiber length of the pulp can be determined by randomly selecting fibers from an optical microscope observation image and arithmetically averaging the fibers.

  The kneading is not particularly limited as long as, for example, pulp (raw cellulose), a thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton can be kneaded at least in a molten state of the thermoplastic resin. For example, a mixing roller, a kneader, a Banbury mixer, an extruder (such as a single-screw or twin-screw extruder) can be used, and a kneader or a twin-screw extruder capable of acting with a high shearing force may be suitably used.

  The kneading step may be performed in an open system in the air or in an atmosphere of an inert gas (a rare gas such as nitrogen or argon), and is usually often performed in a closed kneading system.

  The kneading temperature can be selected according to the type of the thermoplastic resin, and may be, for example, about 150 to 300C, preferably about 170 to 250C, and more preferably about 180 to 230C. The kneading time is not particularly limited, but in the method of the present invention, since the resin composition is often obtained in a short time, the kneading time is, for example, 1 minute to 5 hours, preferably 3 minutes to 3 hours, and more preferably. May be about 5 minutes to 1 hour (especially 8 to 30 minutes).

  The resin composition of the present invention does not require an excessively high preparation temperature (kneading temperature) for preparing the resin composition (first resin composition), and can suppress coloring accompanying heat history.

  In the kneading step, each component may be added to the kneading system in a plurality of times. For example, a composition containing at least pulp and a compound having a 9,9-bisarylfluorene skeleton may be kneaded in advance, and further a thermoplastic resin and an additive may be added.

[Second resin composition and molded article, and method for producing the same]
The second resin composition of the present invention is a resin composition suitable for molding (resin composition for molding), a first resin composition containing a first thermoplastic resin (for example, a masterbatch), Kneading (or mixing) the first resin composition (master batch) and the second thermoplastic resin, including the second thermoplastic resin (diluting the master batch with the second thermoplastic resin) ).

  The second thermoplastic resin may be the thermoplastic resin exemplified as the first thermoplastic resin, and the preferred thermoplastic resin is also the same. The first thermoplastic resin and the second thermoplastic resin may be the same, the same system, or different systems. Usually, the same or the same thermoplastic resin is used.

  In the second resin composition (the total amount of the first thermoplastic resin and the second thermoplastic resin, the fibrillated fiber, and the compound having a 9,9-bis (aryl) fluorene skeleton), the ratio of the fibrillated fiber ( Content) may be, for example, about 1 to 30% by mass, preferably about 2 to 25% by mass, and more preferably about 5 to 20% by mass (for example, about 8 to 15% by mass). If the proportion of the fibrillated fibers is too small, the effect of reinforcing the resin is reduced, and the mechanical strength may be reduced.

  The ratio between the first resin composition (master batch) and the second thermoplastic resin is not particularly limited, and the second resin composition has a desired fibrillated fiber content (fibrillated fiber concentration). For example, the ratio of the second thermoplastic resin may be the same as that of the masterbatch (the first thermoplastic resin, the fibrillated fiber, and the compound having a 9,9-bis (aryl) fluorene skeleton). The amount can be selected from the range of 50 to 1000 parts by mass (for example, 80 to 500 parts by mass), preferably 100 to 400 parts by mass (for example, 120 to 350 parts by mass), more preferably 150 to 100 parts by mass with respect to 100 parts by mass. About 300 parts by mass (for example, 180 to 250 parts by mass).

  The kneading temperature is, for example, a temperature higher than the glass transition temperature (or softening point) of the thermoplastic resin (first and second thermoplastic resins) (or higher than the glass transition temperature and lower than the decomposition temperature of cellulose). For example, the temperature may be about 100 to 300 ° C, preferably about 150 to 250 ° C, and more preferably about 170 to 230 ° C. The kneading time may be, for example, about 30 seconds to 1 hour, preferably about 1 to 30 minutes, and more preferably about 2 to 10 minutes.

  The second resin composition of the present invention has high fluidity (melt fluidity) even if the proportion of the fibrillated fiber is high (even if the fibrillated fiber is contained at a high concentration). The melt flow rate (MFR) of the second resin composition of the present invention is, for example, 100 to 350 g / 10 min when measured under the conditions of a test load of 25 kg, a temperature of 240 ° C., and a nozzle diameter of 1.0 mm × 1.0 mmΦ. (For example, 110 to 300 g / 10 minutes), preferably about 120 to 280 g / 10 minutes (130 to 250 g / 10 minutes), and more preferably about 140 to 220 g / 10 minutes (for example, 150 to 200 g / 10 minutes). You may.

  The melt fluidity of the second resin composition of the present invention is, for example, 80 or more when the melt fluidity (for example, melt flow rate (MFR)) of a single thermoplastic resin as a base resin is 100 ( For example, it may be 85 to 150), preferably 90 or more (for example, 93 to 130), and more preferably 95 or more (for example, about 97 to 110).

  The second resin composition may be a molded article molded by, for example, an injection molding method, an injection compression molding method, an extrusion molding method, a transfer molding method, a blow molding method, a pressure molding method, a casting molding method, or the like. The molded body is not limited to a two-dimensional structure (eg, a film, a sheet, a plate, etc.) but may be a three-dimensional structure (eg, a tube, a rod, a tube, a hollow article, etc.), and may be a housing, a casing, or the like. You may.

  The first resin composition, the second resin composition, and the molded article of the present invention may contain various additives, for example, a stabilizer (an antioxidant, an ultraviolet absorber, a light stabilizer, Heat stabilizers), antistatic agents, flame retardants (phosphorous flame retardants, halogen flame retardants, inorganic flame retardants, etc.), flame retardant aids, impact modifiers, flow improvers, reinforcing materials (filling) Agents, etc.), colorants, hue improvers, lubricants, release agents, dispersants, antibacterial agents, preservatives and the like. These additives may be used alone or in combination of two or more.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Evaluation method of fiber diameter]
In Examples and Comparative Examples, each fiber diameter was measured by the following method.

(Average fiber diameter D1, average fiber length L, average aspect ratio L / D1 of pulp fiber part)
Using a calcium chloride / methanol aqueous solution (mass ratio: anhydrous calcium chloride: methanol: water = 3: 6: 1), components other than the fibrillated fibers in the master batch obtained in Examples or Comparative Examples were eluted, A dispersion of fibrillated fibers having a concentration of 0.2% by mass was prepared. This dispersion was observed with a polarizing microscope (50 times), pulp fiber portions were randomly selected at 30 points, and the fiber diameter (D1i) and fiber length (Li) of each pulp fiber portion were measured (i = 1 to 30). ). Using the measured fiber diameter (D1i) and fiber length (Li), the average fiber diameter D1 and the average fiber length L were calculated by the following equations (5) and (6).

  The average aspect ratio was determined from the ratio of the average fiber length to the average fiber diameter (L / D1).

(Arithmetic average fiber diameter D2, maximum fiber diameter D3, minimum fiber diameter D4, weighted average fiber diameter D5 of fibrillated fibers)
Elution into a calcium chloride / methanol aqueous solution (mass ratio anhydrous calcium chloride: methanol: water = 3: 6: 1) capable of selectively dissolving components other than the fibrillated fibers in the master batches obtained in Examples and Comparative Examples. Then, the components other than the fibrillated fiber were removed, and the fiber provided with the pulp fiber portion and the fibril portion was observed with a scanning electron microscope (SEM) (magnification: 1000). A pulp fiber portion observed in one visual field and a fibril portion having the pulp fiber portion as a trunk are randomly selected to be 50 points, and the fiber diameter of each of the selected 50 points (D2j, j = 1 to 50) Was measured. Using the measured fiber diameter (D2j), the arithmetic average fiber diameter D2 was calculated by the following equation (7). Further, among the measured fiber diameters (D2j), the largest fiber diameter was defined as the maximum fiber diameter (D3), and the smallest fiber diameter was defined as the minimum fiber diameter (D4). The weighted average fiber diameter (D5) was calculated by the following equation (8).

(Polydispersity of fibrillated fiber)
Using the weighted average fiber diameter D5 of the fibrillated fiber and the arithmetic average fiber diameter D2 of the fibrillated fiber obtained by the above method (calculation from the SEM image), the ratio of the weighted average fiber diameter D5 to the arithmetic average fiber diameter D2 (D5 / D2) was defined as the polydispersity of the fiber diameter of the fibrillated fiber.

(Example 1)
For 100 parts by mass of pulp cut into chips of about 2 mm × 5 mm square, 200 parts by mass of polyamide 6 (manufactured by Unitika Ltd., “Nylon 6 A1020BRL”, hereinafter referred to as PA6), 9,9-bis [4- (2-Hydroxyethoxy) phenyl] fluorene (BPEF) (33.5 parts by mass) was kneaded with a kneader ("KRC Kneader S2" manufactured by Kurimoto Tekkosho Co., Ltd.) at a kneading temperature of 200 ° C and a discharge rate of 8.88 kg / h. The masterbatch 1 (first resin composition 1) is prepared by kneading under the conditions of a rotation speed of 300 rpm, and the average fiber diameter, average fiber length of the pulp fiber portion of the fibrillated fibers in the masterbatch 1, The average fiber diameter, the maximum fiber diameter, the minimum fiber diameter, the weighted average fiber diameter, and the polydispersity of the fiber diameter of the fibrillated fibers were measured. FIG. 1 shows the results of observation of a fibrillated fiber in the obtained masterbatch 1 by a polarizing microscope, and FIG. 2 shows the results of observation by a scanning electron microscope (SEM).

  As is clear from the results of FIGS. 1 and 2, it was confirmed that the average fiber length of the pulp fiber portion was maintained, and the pulp fiber was fibrillated in a fibrillated state. The fibrillated fibers were substantially uniformly dispersed in the resin. Further, the obtained master batch 1 had little coloring.

  Using the obtained masterbatch 1 and PA6, kneading is performed with a twin-screw extruder (manufactured by Technovel Corporation, "KZW15TW-45MG-NH") under the conditions of a cylinder temperature of 80 to 225C and a rotation speed of 100 rpm. Vacuum venting was performed to prepare a molding resin composition 1 (second resin composition 1) having a fibrillated fiber concentration (content of fibrillated fibers in the resin composition) of 10% by mass.

  The melt fluidity (melt flow rate, MFR) of the molded resin composition 1 was measured using an elevated flow tester (“CFT-500” manufactured by Shimadzu Corporation) at a test load of 25 kg, a temperature of 240 ° C., and a nozzle diameter of 1. It was measured under the condition of 0 mm × 1.0 mmΦ.

Using the obtained molding resin composition 1, a test piece having a length of 80 mm, a width of 10 mm and a thickness of 4 mm was molded using a small injection molding machine ("HAAKE MiniJet Pro" manufactured by Thermo Fisher Scientific Co., Ltd.). The appearance was evaluated according to the following criteria.
：: Milky white to pale yellow ×: Yellow to brown

  Further, using the test piece prepared as described above, a bending property (bending strength, flexural modulus) of the bending test piece was measured in accordance with JIS K 7171, and an Izod impact test (no notch) was performed in accordance with JIS K 7110.

(Example 2)
A masterbatch 2 was prepared in the same manner as in Example 1 except that PA6 was 169 parts by mass and BPEF was 39.4 parts by mass with respect to 100 parts by mass of the pulp. The fiber diameter, average fiber length, and average aspect ratio, as well as the average fiber diameter, maximum fiber diameter, minimum fiber diameter, weighted average fiber diameter, and polydispersity of the fiber diameter of the fibrillated fiber were measured. FIG. 3 shows the result of observation of the fibrillated fiber in the obtained masterbatch 2 by a polarizing microscope, and FIG. 4 shows the result of observation by a scanning electron microscope (SEM). The obtained masterbatch 2 was less colored as in Example 1.

  Using the obtained masterbatch 2 and PA6, a molding resin composition 2 having a fibrillated fiber concentration of 10% by mass was prepared in the same manner as in Example 1, and each evaluation was performed as in Example 1. Was.

(Comparative Example 1)
Master batch 3 was prepared in the same manner as in Example 1 except that PA6 was 232.9 parts by mass and N-methylpyrrolidone (hereinafter referred to as NMP) was 37.1 parts by mass with respect to 100 parts by mass of pulp. And the average fiber diameter, average fiber length, and average aspect ratio of the pulp fiber portion in the masterbatch 3, the average fiber diameter, the maximum fiber diameter, the minimum fiber diameter, the weighted average fiber diameter, and the fiber diameter of the fibrillated fibers Was measured. FIG. 5 shows the results of observation of the fibrillated fibers in the obtained masterbatch 3 with a polarizing microscope, and FIG. 6 shows the results of observation with a scanning electron microscope (SEM). The obtained master batch 3 was strongly colored, and from the results of FIGS. 5 and 6, it was confirmed that the nanofiber formation had progressed significantly although the average fiber length of the pulp fiber portion was maintained. . Further, in the kneading process by the kneader, NMP was volatilized, and the working environment was very poor.

  Using the obtained masterbatch 3 and PA6, a molding resin composition 3 having a fibrillated fiber concentration of 10% by mass was prepared in the same manner as in Example 1, and each evaluation was performed as in Example 1. Was.

(Comparative Example 2)
In the kneading process by the kneader, the same treatment as in Example 1 was performed except that PA6 was changed to 233.8 parts by mass and BPEF was not added to 100 parts by mass of the pulp. However, the pulp was not sufficiently dispersed during kneading, and clogging occurred in the kneading machine, making it impossible to prepare a master batch.

(Comparative Example 3)
A master batch 4 was prepared in the same manner as in Example 1 except that BPEF was 100 parts by weight and PA6 was not added to 100 parts by weight of the pulp in the kneading process with the kneader. FIG. 7 shows the result of observation of the pulp fiber in the obtained master batch 4 by a polarizing microscope, and FIG. 8 shows the result of observation by a scanning electron microscope (SEM). From the results of FIGS. 7 and 8, it was confirmed that although the obtained master batch 4 was lightly colored, fragmentation of the pulp fiber proceeded and fibrillation did not occur. Therefore, the average fiber diameter, average fiber length, and average aspect ratio were determined using the pulp fiber in the master batch 4 as the pulp fiber part. In addition, the weighted average fiber diameter of the pulp fiber was calculated to be 26.8 μm from the result of measurement with a polarizing microscope, and the polydispersity of the pulp fiber (weighted average fiber diameter / average fiber diameter) was 1.2. Also, from the results of FIGS. 7 and 8, it was confirmed that fragmentation of the pulp fiber proceeded and fibrillation did not occur.

  Using the obtained master batch 4 and PA6, a molding resin composition 4 having a fiber concentration of 10% by mass was prepared in the same manner as in Example 1, and each evaluation was performed as in Example 1.

(Reference Example 1)
Each evaluation was performed in the same manner as in Example 1, except that PA6 was used alone as the molding resin composition.

  Table 1 shows the results of Examples 1 and 2, Comparative Examples 1 and 3, and Reference Example 1.

  As is clear from Table 1, Examples 1 and 2 have a polydispersity of as large as 3 or more and a weighted average fiber diameter of as large as 6 μm or more. It could be confirmed. In Examples 1 and 2, the flexural strength, flexural modulus and impact strength were high, and the melt fluidity was also good. On the other hand, in Comparative Example 1, since the polydispersity was less than 3 and the weighted average fiber diameter was as small as 2.5 μm, it was confirmed that the defibration was progressing too much. The MFR was significantly lower. In Comparative Example 3, fibrillation did not occur, the polydispersity of the pulp fiber was almost monodisperse of 1.2, and the weighted average fiber diameter of the pulp fiber was as large as 26.8 μm. Was not progressing. Comparative Example 3 had a low impact strength.

  INDUSTRIAL APPLICABILITY The resin composition (master batch or resin reinforcing agent), the molded resin composition and the molded article of the present invention can be used for a wide range of uses, as a reinforcing material for resin (for example, polyamide resin), an additive, and a material for a film or sheet. . In addition, since the molding resin composition (molding material) has excellent balance of properties such as toughness, strength, and elastic modulus, for example, various resin molded products [for example, packaging materials for electric / electronic parts, building materials ( Various materials, such as wall materials), civil engineering materials, agricultural materials, packaging materials (containers, cushioning materials, etc.), living materials (daily necessities, etc.), liquid crystal display substrates and solar cell substrates, optical sheets, etc .; Because of its high strength, it can be used for automobile parts (body, hood, door, drive shaft, etc.), sporting goods (golf shafts, tennis racket frames, etc.), leisure goods (fishing rods, etc.). Further, it can be used for molded members in various fields (for example, molded bodies such as a casing and a housing).

Claims (14)

  A resin composition comprising a thermoplastic resin and fibrillated fibers, further comprising a compound having a 9,9-bis (aryl) fluorene skeleton, wherein the fibrillated fibers form a trunk portion; A fibril portion extending in a branch shape from the surface of the pulp fiber portion, wherein the weighted average fiber diameter of the fibrillated fiber is 3 to 20 μm, and the weighted average with respect to the arithmetic average fiber diameter of the fibrillated fiber. A resin composition having a polydispersity represented by a fiber diameter ratio of 3 or more.   The resin composition according to claim 1, wherein the arithmetic average fiber diameter of the fibrillated fibers is 0.5 to 15 m, the maximum fiber diameter of the fibrillated fibers is 40 m or less, and the minimum fiber diameter is 0.01 m or more.   The resin composition according to claim 1 or 2, wherein the pulp fiber portion has an average aspect ratio of 10 or more.   The resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin contains a polyamide resin. The resin composition according to any one of claims 1 to 4, wherein the compound having a 9,9-bisarylfluorene skeleton is a compound represented by the following formula (1).
(Wherein, ring Z is an arene ring, X is a group represented by the following formula (2-1), (2-2), or (2-3), n is an integer of 1 to ³ , R ³ And R ⁴ represent a substituent, p represents 0 or an integer of 1 or more, and k represents an integer of 0 to 4.)
(In the formula, R ¹ is a hydrogen atom or an alkyl group, R ² is an alkylene group, and m 1 and m ² each represent 0 or an integer of 1 or more.)   The resin composition according to claim 5, wherein in the formula (1), X is a group represented by the formula (2-3).   The resin composition according to any one of claims 1 to 6, wherein the proportion of the compound having a 9,9-bisarylfluorene skeleton is 15 to 60 parts by mass relative to 100 parts by mass of the fibrillated fiber.   The resin composition according to any one of claims 1 to 7, wherein the resin composition does not contain an amide-based solvent.   The masterbatch according to claim 1, which is a masterbatch containing the fibrillated fibers in a ratio of 10 to 50% by mass based on the total amount of the thermoplastic resin, the fibrillated fibers, and the compound having the 9,9-bis (aryl) fluorene skeleton. The resin composition according to any one of the above.   The masterbatch according to claim 9, wherein the masterbatch is diluted with a thermoplastic resin, and the fibrillated fiber is added to the total amount of the thermoplastic resin, the fibrillated fiber, and the compound having a 9,9-bis (aryl) fluorene skeleton. The resin composition according to any one of claims 1 to 8, which comprises 30% by mass.   A molded article containing the resin composition according to claim 1.   A method for producing the resin composition according to any one of claims 1 to 9 by kneading pulp, a thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton.   The method according to claim 12, wherein the kneading is performed without using a solvent.   A method for producing the resin composition according to claim 10, wherein the master batch according to claim 9 and a thermoplastic resin are kneaded.