JP7165002B2 - THERMOPLASTIC RESIN COMPOSITION, MOLDED PRODUCT THEREOF, AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Description

TECHNICAL FIELD 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 low environmental load, is a sustainable resource, and has excellent properties such as high elastic modulus, high strength, and low coefficient of linear expansion. Therefore, in recent years, in order to improve the mechanical properties of resins, resin compositions containing cellulose have been proposed as reinforcing materials for resin materials.

For example, Japanese Patent Publication No. 2002-527536 (Patent Document 1) describes a composite material in which cellulose pulp fibers having a purity of alpha cellulose higher than 80% by weight are dispersed in a thermoplastic (for example, polyamide), and the cellulose pulp is It is also described that tensile strength, bending strength, impact strength, etc. are improved by compounding fibers as reinforcing fibers with thermoplastics.

However, in Patent Document 1, when granulating cellulose pulp fibers using a rotating knife cutter or melt-mixing pelletized fibers and polymers, fragmentation of fibers occurs (fiber length becomes shorter), It is described that the reinforcing power of the fibers is reduced. Therefore, in Patent Document 1, fragmentation of fibers cannot be suppressed and a sufficient reinforcing effect cannot be obtained. Furthermore, in Patent Document 1, the dispersibility of fibers in the polymer is also insufficient.

Japanese Patent No. 5885658 (Patent Document 2) describes a thermoplastic polyamide resin composition containing a thermoplastic polyamide resin and cellulose fibers, and the resin composition contains cellulose nanofibers having an average fiber diameter of 500 nm or less. It is described that the mechanical properties and heat resistance can be improved by uniformly dispersing the particles without aggregating them.

However, in Patent Document 2, it is necessary to prepare cellulose fibers in advance to have an average fiber diameter of 500 nm or less. It is necessary to go through a special and complicated production process of preparing a dispersion by mixing the monomers constituting the above, and polymerizing the dispersion while maintaining the dispersed state (in situ polymerization). In order to further improve the mechanical properties of the resin composition, it is advantageous to increase the concentration of the cellulose fiber as a reinforcing material. A resin composition containing cellulose nanofibers at a high concentration cannot be obtained because the fluidity is remarkably lowered.

Japanese Patent Application Laid-Open No. 2018-9095 (Patent Document 3) describes a resin composition containing a polyamide resin, cellulose nanofibers, an amide solvent, and a compound having a 9,9-bis(aryl)fluorene skeleton. It is 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. It is stated that a resin composition can be formed in which the fibers are uniformly dispersed in the polyamide resin.

However, even in Patent Document 3, when the concentration of cellulose nanofibers is high, the fluidity of the resin composition is significantly reduced. Have difficulty. Furthermore, in Patent Document 3, since an amide-based solvent is essential, there are work problems such as volatilization of the solvent in the manufacturing process, and a problem that the resin composition is colored due to the amide-based solvent.

Japanese Patent Publication No. 2002-527536 Japanese Patent No. 5885658 JP 2018-9095 A

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

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

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

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

The present inventors have made intensive studies to achieve the above object, and found that a thermoplastic resin, a pulp (raw material cellulose, cellulose pulp), and a compound having a 9,9-bis(aryl)fluorene skeleton are added. When kneading, the compound having a 9,9-bis(aryl)fluorene skeleton acts as a defibration aid, and surprisingly the pulp is not defibrated to cellulose nanofibers, but is defibrated to an appropriate defibration state, The present inventors have found that the fluidity (melt fluidity) is high even when dispersed in a thermoplastic resin and containing fibers at a high concentration, and completed the present invention.

That is, the resin composition of the present invention is a resin composition containing a thermoplastic resin and fibrillated fibers, further containing 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 branch-like from the surface of the pulp fiber portion, wherein the fibrillated fiber has a weighted average fiber diameter of 3 to 20 μm, and the fibrillated fiber The polydispersity index represented by the ratio of the weighted average fiber diameter to the arithmetic average fiber diameter of the fibers is 3 or more. Further, the fibrillated fibers may have an arithmetic mean fiber diameter of 0.5 to 15 μm, a maximum fiber diameter of 40 μm or less, and a minimum fiber diameter of 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 contain a polyamide-based 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 is an integer of 0 or 1 or more, and k is an integer of 0 to 4).

(In the formula, ^R1 is a hydrogen atom or an alkyl group, ^R2 is an alkylene group, m1 and m2 each represent an integer of 0 or 1 or more).

In formula (1), X may be a group represented by formula (2-3). The ratio 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. Moreover, 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. The first thermoplastic resin and the thermoplastic resin that dilutes the first resin composition may be referred to as the second thermoplastic resin. In the first resin composition of the present invention, fibrillated fibers are added to the total amount of the thermoplastic resin (first thermoplastic resin), the fibrillated fibers, and the compound having a 9,9-bis(aryl)fluorene skeleton. It may be contained at a rate of 10 to 50% by mass. The second resin composition contains fibril It may contain 1 to 30% by mass of synthetic fiber. 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). can adjust the resin composition of the present invention. Specifically, the first resin composition of the present invention is produced by kneading pulp (raw material cellulose), a first thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton. may be produced without using a solvent. The second resin composition can be prepared by kneading the first resin composition (masterbatch) and the second thermoplastic resin.

In this specification, fibrillated fibers (pulp fibers whose surfaces are fibrillated) refer to fibers whose arithmetic mean fiber diameter of the pulp fiber portion has not been defibrated to nanometer size (for example, arithmetic micrometer-sized fibers).

In the present invention, since the compound having a 9,9-bis(aryl)fluorene skeleton acts as a defibration aid for cellulose, the pulp (raw material cellulose) can be easily prepared without special treatment (pretreatment). Pulp (raw material cellulose) can be moderately fibrillated, and the fibrillated fibers produced have a fiber diameter larger than the nanometer size and do not need to be nanofiberized, so that the resin can contain a high concentration of fibrillated fibers. . Moreover, the fluidity of the resin composition can be enhanced. Therefore, the resin composition of the present invention can significantly improve the mechanical properties of thermoplastic resins. Moreover, since it is not necessary to use a predetermined solvent, coloring in the manufacturing process can be greatly reduced.

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

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

(Thermoplastic resin)
The _{thermoplastic} resin (first thermoplastic resin) is not particularly limited. , cyclic olefin resins such as norbornene resins, etc.); modified olefin resins (halogenated olefin resins such as chlorinated polyethylene, graft copolymers such as maleic anhydride grafted polyethylene, ethylene-vinyl acetate copolymers (EVA ), copolymers such as ethylene-vinyl alcohol copolymers, etc.); vinyl chloride resins (polyvinyl chloride resins, polyvinylidene chloride resins, etc.); fluorine resins (polytetrafluoroethylene, etc.); vinyl acetate Resins (polyvinyl acetate or derivatives thereof (polyvinyl alcohol, polyvinyl acetal, etc.), etc.); styrene resins (polystyrene; acrylonitrile-styrene copolymers such as styrene copolymers (AS resins); Acrylonitrile-butadiene-styrene copolymer and other rubber-reinforced polystyrene resins, etc.); (meth)acrylic resins (polymethyl (meth)acrylate, etc.); polyester resins (polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate) , homo- or copolymer polyesters with C _2-4 alkylene C _6-12 arylate units such as polyethylene naphthalate, C _5-10 cycloalkylenediC _1-4 alkylene such as poly(1,4-cyclohexyldimethylene terephthalate) C _6-12 arylate, wholly aromatic polyester (polyarylate) such as polyphenylene arylate, etc.); polycarbonate resin (bisphenol A type polycarbonate resin, etc.); polyamide resin (aliphatic polyamide such as polyamide 6, polyamide 66, cyclo Aromatic polyamides such as alicyclic polyamides formed from alkanedicarboxylic acids and diamines, MXD-6, polyamides formed from terephthalic acid and trimethylhexamethylenediamine, etc.); polyether resins (polyphenylene ether-based resin, polyetherketone-based resin, polyetheretherketone-based resin, etc.); polyphenylene sulfide-based resin; polysulfone-based resin (polysulfone resin, polyethersulfone-based resin, etc.); polyacetal-based resin; polyesters, etc.); thermoplastic elastomers (olefin-based elastomers, styrene-based elastomers, ester-based elastomers, amide-based elastomers, vinyl chloride-based elastomers, fluorine-based elastomers, etc.), and the like. These thermoplastic resins can be used alone or in combination of two or more.

Preferred thermoplastic resins include olefin resins, styrene resins, polyester resins, polycarbonate resins, polyamide resins, ester elastomers, and amide elastomers, and more preferably polyester resins, polyamide resins, ester elastomers, and amide resins. It may be a system elastomer, and from the viewpoint of high mechanical strength such as tensile strength and impact strength and high affinity with fibrillated fibers, it may be particularly a polyamide system resin.

Examples of polyamide-based resins include homopolyamides and copolyamides obtained by copolymerizing homopolyamide components. Examples of homopolyamides include aliphatic polyamide resins (e.g., polyamide 6, polyamide 12, polyamide 11, polyamide 46, polyamide 66, polyamide 610, polyamide 611, polyamide 612, etc.), alicyclic polyamide resins (e.g., diaminomethyl Polymer of cyclohexane and adipic acid, etc.), semi-aromatic polyamide resin or aromatic polyamide resin (e.g., polymer of trimethylhexamethylenediamine and terephthalic acid, polyamide MXD (e.g., metaxylylenediamine and adipic acid polymer, etc.) can be exemplified. Examples of copolyamides 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), more preferably C _6-16 alkylene groups (e.g., C _6-12 alkylene groups) in the main chain of the polymer; at least a hexamethylene group) (e.g., polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 611, polyamide 612, copolyamide 6/11, copolyamide 66/12, etc.) Polyamide 6 and the like are particularly preferred.

The polyamide-based 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 used in many cases 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 (eg, 100 to 250° C.), preferably 220° C. or less (eg, 120 to 220° C.), more preferably 200° C. or less (eg, about 150 to 190° C.). may be

The weight average molecular weight (Mw) of the thermoplastic resin (eg, polyamide resin) can be selected from the range of 5,000 to 1,000,000, for example, 10,000 to 800,000 (eg, 15,000 to 100,000), preferably 20,000 to 600,000 (eg, 23,000 to 70,000), more preferably about 25,000 to 500,000 (eg, 30,000 to 50,000). The dispersity (Mw/Mn) may be, for example, 1-5, preferably 1-3, more preferably 1-2, especially 1-1.5. The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin can be measured in terms of polystyrene by gel permeation chromatography (GPC).

(fibrillated fiber)
Fibrillated fibers (pulp fibers fibrillated on the surface) are fibrillated fibers derived from pulp (raw material cellulose, cellulose). and a fibril portion (branch-like fiber portion) extending branch-like from the surface of the pulp fiber portion, which are dispersed in the resin composition.

The fibrillated fiber may be a modified fiber (or modified fiber) in which at least part of the functional group or reactive group (e.g., hydroxyl group) is modified (e.g., acylated, etherified, etc.). Alternatively, it may be an unmodified fiber that has not undergone any modification treatment.

Modifiers, for example, may have a functional group (e.g., epoxy group, carboxyl group, etc.) capable of bonding (reacting) with hydroxyl groups of cellulose fibers, cationic groups such as ammonium, phosphonium, sulfonium, or You 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 parts by mass or less), preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less with respect to 100 parts by mass of cellulose fibers. may be

From the viewpoint of not impairing the hydrogen bonding property with the thermoplastic resin (eg, polyamide resin), the modification amount is preferably low, for example, the modification rate is 10% by mass or less (eg, 0.01 to 10% by mass). , preferably 5% by mass or less, more preferably 1% by mass or less. The fibrillated fibers of the present invention are usually unmodified fibers that have not undergone any modification treatment because they can be uniformly dispersed in thermoplastic resins (eg, polyamide resins) without modification treatment.

Examples of the pulp (raw material cellulose, cellulose) include pulp having a low content of non-cellulose components such as lignin and hemicellulose, such as plant-derived pulp, animal-derived pulp, and bacterial-derived pulp. Plant-derived pulps include, for example, softwood (pine, fir, spruce, hemlock, cedar, etc.), hardwood (beech, birch, poplar, maple, etc.) wood pulp; hemp (hemp, flax, Manila hemp, ramie, etc.) ), straw, bagasse, mitsumata, bamboo, sugar cane, and other vegetable pulp; cotton linter, bombax cotton, kapok, and other seed hair fiber pulp; Examples of pulp include cellulose contained in nata de coco. These pulps (cellulose) can be used alone or in combination of two or more. Among these pulps (or cellulose), plant-derived cellulose raw materials are preferable, and cellulose derived from wood pulp (e.g., softwood pulp, hardwood pulp, etc.), pulp derived from seed hair fibers (e.g., cotton linter pulp). etc. is more preferable. The pulp may be mechanical pulp obtained by mechanically treating pulp material, but chemical pulp obtained by chemically treating pulp material is preferable because the content of non-cellulose components is small.

The pulp or cellulose (raw material cellulose) preferably has high crystallinity, and the crystallinity of the pulp (cellulose) is, for example, 40 to 100% (eg, 50 to 100%), preferably 60 to 95%. More preferably, it may be about 70 to 90% (especially 75 to 90%), and usually the crystallinity may be 60% or more. The crystallinity of pulp (cellulose) can be measured by an X-ray diffraction method. Examples of the crystal structure of pulp (cellulose) include type I, type II, type III, type IV, etc. Type I crystal structure is preferred because of its excellent elastic modulus.

In the present invention, the fibrillated fiber is a cellulose fiber obtained by miniaturizing (or fibrillating) the fiber surface of pulp (raw material cellulose such as cellulose, cellulose pulp, or cellulose fiber having an average fiber diameter of 10 μm or more). It has a part (pulp fiber part).

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

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

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

Incidentally, the average fiber diameter D1 and the average fiber length L were obtained by using a solvent to obtain fibrillated fibers, a thermoplastic resin, and a fibrillated fiber in a resin composition containing a compound having a 9,9-bis(aryl)fluorene skeleton. A dispersion of fibrillated fibers with a solid content concentration of 0.3 to 1% by mass was prepared by eluting the other components, and the dispersion was observed with a polarizing microscope (magnification: 20 to 50 times) to obtain n points (n is 20 Integer of more than 1) is randomly selected, and the selected n-point fiber diameter (D1i) and fiber length (Li) (i = 1 to n) are used to calculate the following formula (1) and formula ( 2) can be calculated. Specifically, it can be measured by the method described in Examples.

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

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

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

Also, the minimum fiber diameter (D4) of the fibrillated fibers may be, for example, 0.01 μm or more (eg, 0.05 to 5 μm), preferably 0.08 μm or more (eg, 0.1 to 1 μm). , more preferably 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 deteriorate.

As described above, the fibrillated fibers contained in the resin composition of the present invention are characterized by being fibrillated and comprising a fibril portion with a small average fiber diameter and a pulp fiber portion with a large average fiber diameter. Therefore, the weighted average fiber diameter of 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 (eg, 3.5 to 20 μm), preferably 4 to 18 μm (eg, 4.5 to 16 μm), more preferably 5 to 14 μm (eg, 5.5 to 12 μm). If the weighted average fiber diameter is too large, the aspect ratio may decrease and high mechanical properties may not be obtained, and if it is too small, the melt fluidity may decrease.

Each fiber diameter (D2 to D5) of the fibrillated fibers is the fibrillated fiber, the thermoplastic resin, and the fibrillated fiber other than the fibrillated fiber in the resin composition containing the compound having a 9,9-bis(aryl)fluorene skeleton. The components are selectively eluted in a soluble solvent, components other than the fibrillated fibers are removed, and the pulp fiber portion and the fiber with the fibril portion are observed with a scanning electron microscope (magnification: 1000 times). A total of m points (m is an integer of 20 or more) of the fibril portions are randomly selected, and the fiber diameters (D2j, j=1 to m) of the selected m points are used. The pulp fiber part and the fibril part of the fibrillated fiber will be explained, for example, based on FIG. 2 of Example 1. may be each fiber of the plurality of fibers within the circle. The arithmetic mean fiber diameter D2 can be calculated by the arithmetic mean of the fiber diameters D2j shown in the following formula (3). The diameter can be D4. Also, the weighted average fiber diameter D5 can be calculated by the following formula (4). Specifically, it can be measured by the method described in Examples.

The fiber diameter polydispersity (D5/D2) of the fibrillated fibers may be, for example, 3 or more (eg, 3 to 20), preferably 3.5 or more (eg, 3.5 to 10), More preferably, it may be 4 or more (eg, 4 to 8), particularly 4.5 or more (eg, 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 fibrillated fibers 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 concentration of fibrillated fibers is high, it is possible to suppress the deterioration of the fluidity of the resin composition. The ratio (content) of the fibrillated fibers is, for example, 10 to 10, relative to the total amount of the thermoplastic resin, the fibrillated fibers, and the compound having a 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 (eg, 28 to 35% by mass). If the ratio of fibrillated fibers is too low, the reinforcing effect may decrease, and if the ratio of fibrillated fibers is too high, fluidity may decrease.

Further, the ratio of fibrillated fibers in the first resin composition may be, for example, 10 to 100 parts by mass with respect to 100 parts by mass of the thermoplastic resin (first thermoplastic resin), preferably It may be 20 to 80 parts by mass, more preferably 40 to 70 parts by mass. If the ratio of fibrillated fibers is too small, defibration of the pulp will be difficult to progress, and the average fiber diameter may become excessively large. The aspect ratio tends to decrease, and the fibrillated fibers are strongly aggregated through hydrogen bonding, resulting in a decrease in dispersibility.

The resin composition may contain cellulose nanofibers (cellulose nanofibers) obtained by defibrating (nanofibering) pulp fibers to a nanometer-sized fiber diameter. The number ratio of fibrillated fibers and cellulose nanofibers is, for 100 fibrillated fibers, for example, 0 to 50 (eg, 0.01 to 30), preferably 0 to 20 (eg, 0.01 to 15). , and more preferably about 0 to 10 (eg, 0.01 to 5), and it is generally preferred not to contain cellulose nanofibers.

(Compound having a 9,9-bis(aryl)fluorene skeleton)
The resin composition of the present invention contains a 9,9-bis(aryl)fluorene skeleton as a fibrillation aid for relaxing hydrogen bonds acting between pulp fibers and fibrillating pulp to an appropriate fibrillation state. (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 reactive derivatives of the carboxyl group include alkoxycarbonyl groups ( _C1-4 alkoxy-carbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group), acid halide groups (haloformyl groups such as acid chloride group and acid bromide group). etc. can be exemplified. The epoxy group may be a glycidyl group as long as it contains an oxirane ring.

A representative 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 is an integer of 0 or 1 or more, and k is an integer of 0 to 4].

(In the formula, ^R1 is a hydrogen atom or an alkyl group, ^R2 is an alkylene group, m1 and m2 each represent an integer of 0 or 1 or more).

In the formula (1), examples of the arene ring represented by ring Z include monocyclic arene rings such as benzene ring, polycyclic arene rings, and the like. They include arene rings (condensed polycyclic hydrocarbon rings), ring-assembled arene rings (ring-assembled aromatic hydrocarbon rings), and the like.

The condensed polycyclic arene ring includes, for example, condensed bicyclic arene (e.g., condensed bicyclic C _10-16 arene such as naphthalene) ring, condensed tricyclic arene (e.g., anthracene, phenanthrene, etc.) ring, and the like. Condensed bi- to tetracyclic arene rings can be exemplified. Preferred condensed polycyclic arene rings include naphthalene ring, anthracene ring and the like, and naphthalene ring is particularly preferred. The two rings Z may be the same or different rings.

The ring-assembled arene ring includes a biarene ring, for example, a biphenyl ring, a binaphthyl ring, a biC _6-12 arene ring such as a phenylnaphthalene ring (1-phenylnaphthalene ring, 2-phenylnaphthalene ring, etc.), a tellarene ring, for example, Teru C _6-12 arene ring such as terphenylene ring can be exemplified. Preferred ring-assembled arene rings include biC _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, a naphthalene ring.

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

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

The number m2 of oxyalkylene groups (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 0 to 5 (eg 1 to 5), more preferably 0 to 4 (eg 1 to 4), particularly 0 to 3 (eg 1 to 3), usually 0 to 2 (eg 0 or 1) may be When m2 is 2 or more, the types of alkylene groups ^R2 may be the same or different. Also, the types of substituents R ² may be the same or different in the same or different rings Z.

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

The group X can be substituted at any suitable position on the ring Z. For example, when the ring Z is a benzene ring, the phenyl group at the 2-, 3-, 4-position (especially the 3-position and/or 4-position), and when the ring Z is a naphthalene ring, it is often substituted at the 5- to 8-positions of the naphthyl group. The 1-position or 2-position of is substituted (substituted in a 1-naphthyl or 2-naphthyl relationship), and the 1,5-position, 2,6-position, etc. relationship (especially n is 1, the group X is often substituted in the 2,6-position relationship). Moreover, when the substitution number 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. good. For example, the 3-position or 4-position of the biphenyl ring may be bonded to the 9-position of the fluorene, and when the 3-position of the biphenyl ring is bonded to the 9-position of the fluorene, the substitution position of the carbonyl group is For example, 2-position, 4-position, 5-position, 6-position, 2'-position, 3'-position and 4'-position of the biphenyl ring, preferably 6-position , 4′-position (particularly, 6-position) and the like. When the 4-position of the biphenyl ring is bonded to the 9-position of the fluorene, the substitution positions of the carbonyl group are the 2-position, 3-position, 2'-position, 3'-position, 4'-position of the biphenyl ring. It may be substituted at any position, preferably 2-position or 4′-position (especially 2-position).

In the above formula (1), the substituent R ³ includes a halogen atom (e.g., 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 groups such as s-butyl group, t-butyl group, preferably linear or branched C _1-6 alkyl groups, more preferably linear or branched chain C _1-4 alkyl group, etc.), cycloalkyl group (C _5-10 cycloalkyl group such as cyclopentyl group, cyclohexyl group, etc.), aryl group [phenyl group, alkylphenyl group (methylphenyl group (tolyl group) , dimethylphenyl group (xylyl group), etc.), biphenyl group, C _6-12 aryl group such as naphthyl group], aralkyl group (benzyl group, C _6-10 aryl-C _1-4 alkyl group such as phenethyl group, etc.) , alkoxy groups (e.g., linear or branched C _1-10 alkoxy groups such as methoxy, ethoxy, propoxy, n-butoxy, isobutoxy, t-butoxy, etc.), cycloalkoxy groups (e.g., , C _5-10 cycloalkyloxy groups such as cyclohexyloxy groups), aryloxy groups (e.g. C _6-10 aryloxy groups such as phenoxy groups), aralkyloxy groups (e.g. C _6-10 aryl-C _1-4 alkyloxy group, etc.), alkylthio group (e.g., C _1-10 alkylthio group such as methylthio group, ethylthio group, propylthio group, n-butylthio group, t-butylthio group, etc.), cyclo Alkylthio groups (e.g., C _5-10 cycloalkylthio groups such as cyclohexylthio groups), arylthio groups (e.g., C _6-10 arylthio groups such as thiophenoxy groups), aralkylthio groups (e.g., benzylthio groups) C _6-10 aryl-C _1-4 alkylthio group, etc.), acyl group (e.g., C _1-6 acyl group such as acetyl group, etc.), nitro group, cyano group, dialkylamino group (e.g., dimethylamino group, etc.) di-C _1-4 alkylamino group, etc.), dialkylcarbonylamino group (eg, di(C _1-4 alkyl-carbonyl)amino group such as diacetylamino group, etc.).

Among these substituents R3 ^, representative examples are halogen atoms, hydrocarbon groups (alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, etc.), alkoxy groups, acyl groups, nitro groups, cyano groups, and substituted amino groups. group etc. can be illustrated. Preferred substituents R ³ include alkyl groups (linear or branched C _1-4 alkyl groups such as methyl group and ethyl group), alkoxy groups (linear or branched C _{1 -4} alkoxy group), particularly alkyl groups (especially linear or branched C _1-3 alkyl groups such as methyl group) are preferred. In addition, when the substituent R ³ is an aryl group, the substituent R ³ may form the ring-assembled arene ring together with the ring Z. The types of substituents R ³ may be the same or different on the same or different rings Z.

The coefficient p of the substituent R ³ can be appropriately selected depending on the type of ring Z, and may be, for example, an integer of about 0 to 8, an integer of 0 to 4, preferably 0 to 3 (eg, 0 to 2), especially 0 or 1. In particular, when p is 1, ring Z may be a benzene ring, naphthalene ring or biphenyl ring ^, and substituent R3 may be a methyl group.

As the substituent ^R4 , a cyano group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a carboxyl group, an alkoxycarbonyl group (e.g., a _C1-4 alkoxy-carbonyl group such as a methoxycarbonyl group, etc.), an alkyl group (C _1-6 alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group and t-butyl group), aryl groups (C _6-10 aryl groups such as phenyl group) and the like.

Among these substituents R ⁴ , linear or branched C _1-4 alkyl groups (especially C _1-3 alkyl groups such as methyl groups), carboxyl groups or C _1-2 alkoxy-carbonyl groups, cyano Groups and halogen atoms are preferred. The substitution number k is an integer from 0 to 4 (eg 0 to 3), preferably an integer from 0 to 2 (eg 0 or 1), especially 0. The substitution number k may be the same or different from each other, and when k is 2 or more, the type of the substituent R ⁴ may be the same or different from each other, and the two benzene rings of the fluorene ring are substituted. The types of substituents ^R4 may be the same or different. Further, the substitution position of the substituent R ⁴ is not particularly limited, and may be, for example, 2-position to 7-position (2-position, 3-position and/or 7-position, etc.) of the fluorene ring.

Specific fluorene compounds having group X represented by formula (2-1) include 9,9-bis(carboxyaryl)fluorene where n=1, p=k=0 and m1=0, such as 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- aryl)fluorene compounds such as 9,9-bis(4-(carboxymethyl)phenyl)fluorene, 9,9-bis(4-(2-carboxyethyl)phenyl)fluorene, 9,9-bis(3-( 9,9-bis(6-(carboxymethyl)-1-naphthyl)fluorene such as carboxymethyl)phenyl)fluorene, 9,9-bis(5-(carboxymethyl)-1-naphthyl)fluorene, 9,9-bis(6-(carboxymethyl)-1-naphthyl)fluorene Examples include bis(carboxyC _{1-6 alkylC 6-10} aryl)fluorene. These fluorene compounds can be used alone or in combination of two or more.

A specific fluorene compound having an epoxy group-containing group X represented by formula (2-2) is 9,9-bis(glycidyloxyaryl) where n = 1, p = k = 0 and m2 = 0. fluorenes such as 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-bis(6-glycidyloxy-2-naphthyl)fluorene; n=1, p=k=0, m2=1-5 9,9-bis(glycidyloxy(poly)alkoxyaryl)fluorene, such as 9,9-bis(4-(2-glycidyloxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-glycidyloxy propoxy)phenyl)fluorene, 9,9-bis(5-(2-glycidyloxyethoxy)-1-naphthyl)fluorene, 9,9-bis(6-(2-glycidyloxyethoxy)-2-naphthyl)fluorene, etc. 9,9-bis(glycidyloxy(poly)C _2-4 alkoxyC _6-10 aryl)fluorene of; 9,9-bis(alkyl- 9,9-bis(C _1-4 alkyl-glycidyloxyC _6-10 aryl)fluorene such as 9,9-bis(3-methyl-4-glycidyloxyphenyl)fluorene; n = 1, p = 1, k = 0, m2 = 1-5, for example 9,9-bis(3-methyl-4- 9,9-bis(C _1-4 alkyl-glycidyloxy(poly)C _2-4 alkoxyC _6-10 aryl)fluorene such as (2-glycidyloxyethoxy)phenyl)fluorene; n=1, p=1, 9,9-bis(aryl-glycidyloxyaryl)fluorenes with k=0 and m=0, for example 9,9-bis(3-phenyl-4-glycidyloxyphenyl)fluorenes such as 9,9-bis( C _6-10 aryl-glycidyloxy C _6-10 aryl)fluorene; 9,9-bis(aryl-glycidyloxy(poly)alkoxyaryl where n=1, p=1, k=0, m2=1-5 ) fluorenes, such as 9,9-bis(3 - 9,9-bis(C _6-10 aryl-glycidyloxy (poly)C _2-4 alkoxyC _6-10 aryl)fluorene such as phenyl-4-(2-glycidyloxyethoxy)phenyl)fluorene; n=2 , p=0, k=0, m=0, 9,9-bis(di(glycidyloxy)aryl)fluorene, such as 9,9-bis(3,4-di(glycidyloxy)phenyl)fluorene, etc. 9,9-bis(di(glycidyloxy)C _6-10 aryl)fluorene of; 9,9-bis(di(glycidyloxy( Poly)alkoxy)aryl)fluorenes, for example 9,9-bis(di(glycidyloxy(poly)C _2-4 Alkoxy)C _6-10 aryl)fluorene and the like can be exemplified. These fluorene compounds can be used alone or in combination of two or more.

The fluorene compound having an epoxy-containing group X represented by the formula (2-2) may be a monomer or a polymer (eg, dimer, trimer, etc.). However, from the viewpoint of sufficiently suppressing yellowing (coloration), it is preferable not to contain a multimer. A fluorene compound having a glycidyl group usually contains at least a monomer in many cases, and may be, for example, a mixture of a monomer, a dimer and a trimer.

Further, as a specific fluorene compound having a hydroxyl-containing group X represented by formula (2-3), in the fluorene compound having group X represented by the above formula (2-2), the glycidyloxy group is Examples include compounds in which groups are substituted, 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, 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 alkoxyC _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 AlkoxyC _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- Monomers and polymers (dimers, trimers, etc.) of fluorene compounds having a glycidyloxy group represented by the formula (2-2) such as _10aryl )fluorene; 9,9-bis(hydroxy C _6-10 aryl)fluorene, 9,9-bis(hydroxy(poly)C _2-4 alkoxyC _6-10 aryl)fluorene, 9,9-bis(C _1-4 alkyl- _{hydroxyC 6-10} aryl) Fluorene, 9,9-bis(C _1-4 alkyl-hydroxy(poly)C _2-4 alkoxyC _6-10 aryl)fluorene, 9,9-bis(C _6-10 aryl- _{hydroxyC 6-10} aryl) Fluorene, 9,9-bis(C _6-10 aryl-hydroxy(poly)C _2-4 alkoxyC _6-10 aryl)fluorene, 9,9-bis(dihydroxyC _6-10 aryl)fluorene, 9,9- Examples include fluorene compounds having a hydroxyl group represented by the above formula (2-3) such as bis(dihydroxy(poly)C _2-4 alkoxy)C _6-10 aryl)fluorene, and more preferably thermoplastic resins. From the viewpoint of compatibility with, heat resistance, and suppression of coloring, it may be a fluorene compound having a hydroxyl group represented by the formula (2-3), particularly 9,9-bis[4-(2-hydroxy 9,9-bis(hydroxy(poly)C _2-4 alkoxyC _6-10 aryl)fluorene such as ethoxy)phenyl]fluorene (BPEF). The “(poly)C _2-4 alkoxy” means that the repeating number m2 of the C _2-4 alkoxy group is an integer of 1 or more.

In the present invention, the fluorene compound also acts as a modifier or additive for the resin composition, can improve the dispersibility (or affinity) of the fibrillated fibers in the resin composition, and can improve the mechanical strength. . In particular, a fluorene compound having an epoxy group (glycidyloxy group) represented by formula (2-2) is advantageous because it can sufficiently improve toughness. On the other hand, if it is a fluorene compound having a group X represented by formula (2-1) or (2-3) (especially a fluorene compound having a hydroxyl group represented by formula (2-3)), mechanical strength In addition, because it also acts as a plasticizer, it is possible to suppress the increase in the viscosity of the resin composition (improve the melt fluidity). Therefore, even if the fibrillated fiber is contained at a high concentration, the melt flowability of the resin composition can be suppressed, and the mechanical strength (for example, strength, toughness, rigidity, etc.) and heat resistance of the thermoplastic resin can be greatly improved. can. In addition, there is no coloring of the resin composition due to the fluorene compound, and the fluorene compound also acts as a plasticizer, so there is no need to raise the preparation temperature (kneading temperature) for preparing the resin composition, and heat history It is possible to suppress the coloring associated with Therefore, coloring can be greatly suppressed in the manufacturing process.

The resin composition may substantially contain a fluorene compound, and the fluorene compound and the fibrillated fiber are bonded (e.g., ether bond, ester bond, etc.) (fibrillated fiber is ether bond, ester bond, etc.) modified with a fluorene compound bound with ), 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 (eg, 5 to 80 parts by mass) relative to 100 parts by mass of the fibrillated fiber, and is, for example, 10 to 70 parts by mass (eg, 15 to 15 parts by mass). 60 parts by mass), preferably 25 to 50 parts by mass, more preferably 28 to 45 parts by mass (eg, 30 to 40 parts by mass). If the ratio of the fluorene compound to the fibrillated fibers is too small, the action (effect) as the fibrillating aid is insufficient, the fibrillated fibers are not sufficiently fibrillated, and the fluidity of the resulting resin composition decreases. However, if the amount of the fluorene compound is too large, the melt viscosity of the resin composition is significantly lowered, the fibrillated fibers are not sufficiently defibrated, and the ratio of low-molecular-weight compounds in the resin composition is increased, resulting in There is a risk that the physical properties of the

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 (eg, 15 to 25 parts by mass). If the ratio of the fluorene compound to the thermoplastic resin is too low, the fluidity of the resin composition may be lowered, or coloration (coloration due to heat history) may occur during the manufacturing process.

Further, the proportion of the fluorene compound may be, for example, 1 to 30% by mass, preferably It may be about 5 to 20% by mass, more preferably about 8 to 16% by mass (eg, 9 to 14% by mass). If the proportion of the fluorene compound is too low, the effect of dispersing the pulp fibers in the resin composition by the fluorene compound may be reduced. is likely to decrease.

(solvent)
The resin composition of the present invention may contain a solvent if necessary. preferably not included. Moreover, if 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 may be harmed by volatilization of the solvent. For example, if the solvent is an amide (amide-based solvent) that acts as a pulp defibrating agent, the fibrillation of the pulp proceeds excessively (for example, fibrillation to nanometer size), and the melt fluidity is significantly reduced. However, coloration derived from the amide solvent may occur.

[Method for producing resin composition (first resin composition)]
The first resin composition (masterbatch, kneaded composition) of the present invention is prepared by combining pulp, a thermoplastic resin, and - 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 defibration aid, and the pulp is defibrated to a moderate defibration state (pulp fibers whose surface is fibrillated), and disperse to Therefore, it is not necessary to subject the pulp (raw material cellulose) to a refinement treatment in advance or to modify the hydroxyl groups on the surface of the cellulose. There is no need to prepare an emulsion of the fiber and the resin, and the resin composition can be easily prepared by a one-step operation of kneading.

In addition, since the compound having a 9,9-bisarylfluorene skeleton also acts as a plasticizer, there is no need to raise the preparation temperature (kneading temperature) for preparing the resin composition, and the heat history in the manufacturing process Accompanying coloring can also be suppressed.

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

Kneading is not particularly limited as long as, for example, pulp (raw material cellulose), a thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton can be kneaded in a state in which at least the thermoplastic resin is molten, and a conventional method. For example, a mixing roller, a kneader, a Banbury mixer, an extruder (single-screw or twin-screw extruder, etc.) can be used, and a kneader, a twin-screw extruder, etc. capable of applying a high shearing force may be preferably used.

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

The kneading temperature can be selected according to the type of thermoplastic resin, and may be, for example, about 150 to 300°C, preferably about 170 to 250°C, more preferably about 180 to 230°C. The kneading time is not particularly limited, but since the resin composition can be obtained in a short time in many cases in the method of the present invention, 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 coloration associated with heat history.

In the kneading step, each component may be added to the kneading system in multiple batches. For example, a composition containing at least pulp and a compound having a 9,9-bisarylfluorene skeleton may be kneaded in advance, and the thermoplastic resin and additives may be added.

[Second resin composition, molded article, and method for producing the same]
The second resin composition of the present invention is a resin composition suitable for molding (molding resin composition), and includes a first resin composition (for example, a masterbatch) containing a first thermoplastic resin, including a second thermoplastic resin, kneading (or mixing) the first resin composition (masterbatch) and the second thermoplastic resin (diluting the masterbatch with the second thermoplastic resin ) can be manufactured by

The second thermoplastic resin may be any of the thermoplastic resins exemplified as the first thermoplastic resin, and the same applies to preferred thermoplastic resins. The first thermoplastic resin and the second thermoplastic resin may be the same, the same system, or different systems, and usually the same or the same system thermoplastic resin is used.

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

The ratio of the first resin composition (masterbatch) 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 is the masterbatch (the first thermoplastic resin, the fibrillated fiber, and the compound having a 9,9-bis(aryl)fluorene skeleton (Total amount) 100 parts by weight, can be selected from the range of 50 to 1000 parts by weight (e.g., 80 to 500 parts by weight), preferably 100 to 400 parts by weight (e.g., 120 to 350 parts by weight), more preferably 150 parts by weight It may be about 300 parts by mass (eg, 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 (the first and second thermoplastic resins) (or a temperature higher than the glass transition temperature and lower than the decomposition temperature of cellulose). For example, it may be about 100 to 300°C, preferably 150 to 250°C, more preferably about 170 to 230°C. The kneading time may be, for example, 30 seconds to 1 hour, preferably 1 to 30 minutes, more preferably 2 to 10 minutes.

The second resin composition of the present invention has high fluidity (melt fluidity) even when the proportion of fibrillated fibers is high (even when the composition contains fibrillated fibers 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 minutes 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. (eg, 110 to 300 g/10 min), preferably 120 to 280 g/10 min (130 to 250 g/10 min), more preferably 140 to 220 g/10 min (eg, 150 to 200 g/10 min). may

Further, the melt fluidity of the second resin composition of the present invention is, for example, 80 or more ( For example, 85 to 150), preferably 90 or more (eg, 93 to 130), more preferably 95 or more (eg, about 97 to 110).

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

The first resin composition, the second resin composition, and the molded article of the present invention may contain various additives such as stabilizers (antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, etc.), antistatic agents, flame retardants (phosphorus flame retardants, halogen flame retardants, inorganic flame retardants, etc.), flame retardant aids, impact modifiers, fluidity modifiers, reinforcing materials (filling agents, etc.), coloring agents, hue modifiers, lubricants, release agents, dispersants, antibacterial agents, preservatives, and the like. These additives may be used alone or in combination of two or more.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is not limited by 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 portion)
Calcium chloride/methanol aqueous solution (mass ratio of anhydrous calcium chloride:methanol:water=3:6:1) was used to elute components other than the fibrillated fibers in the masterbatch obtained in Examples or Comparative Examples, and solids were obtained. A dispersion of fibrillated fibers with a concentration of 0.2% by weight was prepared. This dispersion was observed with a polarizing microscope (50x magnification), 30 pulp fiber portions were randomly selected, 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 formulas (5) and (6).

Also, the average aspect ratio was obtained from the ratio of the average fiber length to the average fiber diameter (L/D1).

(Arithmetic mean fiber diameter D2, maximum fiber diameter D3, minimum fiber diameter D4, weighted mean fiber diameter D5 of fibrillated fibers)
Components other than the fibrillated fibers in the masterbatches obtained in Examples and Comparative Examples were eluted into a calcium chloride/methanol aqueous solution (mass ratio of anhydrous calcium chloride:methanol:water=3:6:1) capable of selectively dissolving them. The fibers other than the fibrillated fibers were removed, and the pulp fiber portion and the fiber with the fibril portion were observed with a scanning electron microscope (SEM) (1000x magnification). A total of 50 points of the pulp fiber portion observed in one visual field and the fibril portion having the pulp fiber portion as a stem were selected at random, and the fiber diameter (D2j, j=1 to 50) of each of the 50 selected points. was measured. Using the measured fiber diameter (D2j), the arithmetic mean fiber diameter D2 was calculated by the following formula (7). 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). Moreover, the weighted average fiber diameter (D5) was calculated by the following formula (8).

(Polydispersity of fibrillated fiber)
Using the weighted average fiber diameter D5 of the fibrillated fibers and the arithmetic average fiber diameter D2 of the fibrillated fibers 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 fibers.

(Example 1)
200 parts by mass of polyamide 6 (manufactured by Unitika Ltd., "Nylon 6 A1020BRL", hereinafter referred to as PA6), 9,9-bis [4- 33.5 parts by mass of (2-hydroxyethoxy)phenyl]fluorene (BPEF) is kneaded with a kneader (manufactured by Kurimoto, Ltd., "KRC Kneader S2") at a temperature of 200 ° C. and a discharge rate of 8.88 kg / h. , Kneading at a rotation speed of 300 rpm to prepare a masterbatch 1 (first resin composition 1), and measuring the average fiber diameter, average fiber length, and the average aspect ratio, as well as the average fiber diameter, maximum fiber diameter, minimum fiber diameter, weighted average fiber diameter and polydispersity of the fibrillated fibers. The results of polarizing microscope observation of the fibrillated fibers in the obtained masterbatch 1 are shown in FIG. 1, and the results of scanning electron microscope (SEM) observation are shown in FIG.

As is clear from the results of FIGS. 1 and 2, it was confirmed that the surface of the pulp fibers was fibrillated while the average fiber length of the pulp fiber portion was maintained. Also, the fibrillated fibers were dispersed substantially uniformly in the resin. Moreover, the obtained masterbatch 1 was less colored.

Using the obtained masterbatch 1 and PA6, a twin-screw extruder (manufactured by Technobell Co., Ltd., "KZW15TW-45MG-NH") is kneaded under the conditions of a cylinder temperature of 80 to 225 ° C. 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 ratio of fibrillated fibers in the resin composition) of 10% by mass.

The melt fluidity (melt flow rate, MFR) of molding resin composition 1 was measured using an elevated flow tester ("CFT-500" manufactured by Shimadzu Corporation) under a test load of 25 kg, a temperature of 240°C, and a nozzle diameter of 1.5 kg. It was measured under the conditions 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 (manufactured by Thermo Fisher Scientific Co., Ltd., "HAAKE MiniJet Pro"). , the appearance was evaluated according to the following criteria.
○: Milky white to pale yellow ×: Yellow to dark brown

In addition, using the test piece prepared above, bending properties (bending strength, bending elastic modulus) of the bending test piece were measured according to JIS K 7171, and an Izod impact test (without notch) was performed according to JIS K 7110.

(Example 2)
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 pulp, and the average of the pulp fiber part in masterbatch 2 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 fiber diameter polydispersity of the fibrillated fibers were measured. The results of polarizing microscope observation of the fibrillated fibers in the obtained masterbatch 2 are shown in FIG. 3, and the results of scanning electron microscope (SEM) observation are shown in FIG. The resulting 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 in the same manner as in Example 1. rice field.

(Comparative example 1)
Masterbatch 3 in the same manner as in Example 1 except that 232.9 parts by mass of PA6 was used with respect to 100 parts by mass of pulp, and 37.1 parts by mass of N-methylpyrrolidone (NMP) was used instead of BPEF. was prepared, and the average fiber diameter, average fiber length, and average aspect ratio of the pulp fiber portion in the masterbatch 3, and the average fiber diameter, maximum fiber diameter, minimum fiber diameter, weighted average fiber diameter and fiber diameter of the fibrillated fibers was measured. The results of polarizing microscope observation of the fibrillated fibers in the obtained masterbatch 3 are shown in FIG. 5, and the results of scanning electron microscope (SEM) observation are shown in FIG. The obtained masterbatch 3 was strongly colored, and from the results of FIGS. 5 and 6, it was confirmed that although the average fiber length of the pulp fiber part was maintained, the nanofiberization was significantly progressed. . In addition, NMP volatilized during the kneading process using a kneader, and the working environment was in a very bad situation.

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 in the same manner as in Example 1. rice field.

(Comparative example 2)
The same treatment as in Example 1 was carried out, except that PA6 was 233.8 parts by mass with respect to 100 parts by mass of pulp in the kneading process using a kneader, and BPEF was not added. However, the pulp was not sufficiently dispersed during kneading, clogging the kneader, and the masterbatch could not be prepared.

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

Using the obtained masterbatch 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 in the same manner as in Example 1.

(Reference example 1)
Each evaluation was performed in the same manner as in Example 1 using PA6 alone as a 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, in Examples 1 and 2, the polydispersity index is as large as 3 or more and the weighted average fiber diameter is as large as 6 μm or more, which indicates that the pulp is in a moderately defibrated state. It could be confirmed. Moreover, Examples 1 and 2 had high flexural strength, flexural modulus and impact strength, and also had good melt fluidity. On the other hand, Comparative Example 1 has a polydispersity of less than 3 and a weighted average fiber diameter as small as 2.5 μm. MFR was remarkably low. In Comparative Example 3, no fibrillation occurred, the polydispersity of the pulp fibers was 1.2, which was almost monodisperse, and the weighted average fiber diameter of the pulp fibers was as large as 26.8 μm, so that the fibers were almost defibrated. was confirmed not to have progressed. Moreover, the impact strength of Comparative Example 3 was low.

The resin composition (masterbatch or resin reinforcing agent), molded resin composition, and molded article of the present invention can be used in a wide range of applications, such as reinforcing materials for resins (e.g., polyamide resins), additives, and materials for films and sheets. . In addition, molding resin compositions (molding materials) have well-balanced characteristics such as toughness, strength, and elastic modulus. wall materials, etc.), civil engineering materials, agricultural materials, packaging materials (containers, cushioning materials, etc.), daily necessities, etc.], various materials such as liquid crystal display substrates and solar cell substrates; optical sheets, etc.; Due to its high strength, it can be used for automobile parts (body, hood, door, drive shaft, etc.), sporting goods (golf shaft, tennis racket frame, etc.), and leisure goods (fishing rod, etc.). In addition, it can be used for molded members in various fields (for example, moldings such as casings and housings).

Claims (13)

A first resin composition comprising a first thermoplastic resin and fibrillated fibers, further comprising a compound having a 9,9-bis(aryl)fluorene skeleton, wherein the fibrillated fibers form a trunk and a fibril portion extending branch-like from the surface of the pulp fiber portion, wherein the weighted average fiber diameter of the fibrillated fibers is 3 to 20 μm, and the arithmetic mean of the fibrillated fibers is A first resin composition having a polydispersity of 3 or more, which is represented by the ratio of the weighted average fiber diameter to the fiber diameter, and containing no amide solvent. The first resin composition according to claim 1, wherein the fibrillated fibers have an arithmetic mean fiber diameter of 0.5 to 15 µm, a maximum fiber diameter of 40 µm or less, and a minimum fiber diameter of 0.01 µm or more. thing. 3. The first resin composition according to claim 1, wherein the average aspect ratio of the pulp fiber portion is 10 or more. The first resin composition according to any one of claims 1 to 3, wherein the first thermoplastic resin contains a polyamide-based resin. The first 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 represents a substituent, p is an integer of 0 or 1 or more, and k is an integer of 0 to 4.)

(In the formula, ^R1 is a hydrogen atom or an alkyl group, ^R2 is an alkylene group, m1 and m2 each represent an integer of 0 or 1 or more). 6. The first resin composition according to claim 5, wherein X in formula (1) is a group represented by formula (2-3). The first resin composition according to any one of claims 1 to 6, wherein the ratio of the compound having a 9,9-bisarylfluorene skeleton is 15 to 60 parts by mass with respect to 100 parts by mass of the fibrillated fiber. 1. A masterbatch containing fibrillated fibers in a proportion of 10 to 50% by mass with respect to the total amount of the first thermoplastic resin, fibrillated fibers and the compound having a 9,9-bis(aryl)fluorene skeleton. 8. The first resin composition according to any one of 1 to 7. The first resin composition according to any one of claims 1 to 8 is diluted with a second thermoplastic resin, the first and second thermoplastic resins, fibrillated fibers and 9,9-bis(aryl ) A second resin composition containing fibrillated fibers at a ratio of 1 to 30% by mass with respect to the total amount of compounds having a fluorene skeleton. A molded article containing a resin composition, the molded article containing the following resin composition (a) or (b) .
(a) the first resin composition according to any one of claims 1 to 8
(b) the second resin composition according to claim 9; A method for producing the first resin composition according to any one of claims 1 to 8 by kneading pulp, a first thermoplastic resin, and a compound having a 9,9-bisarylfluorene skeleton. 12. The method of claim 11, wherein the kneading is done without solvent. A method for producing the second resin composition according to claim 9 by kneading the first resin composition according to any one of claims 1 to 8 and a second thermoplastic resin.

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