Resin composition, and use and production method thereof

Abstract

To provide a thermoplastic resin composition containing a plant-derived filler and having high mechanical properties.SOLUTION: The resin composition is prepared by combining a thermoplastic resin, a plant-derived filler and a diacetal compound represented by formula (1). (wherein Z1 and Z2 independently represent an arene ring, R1 and R2 independently represent an alkyl group, n and m independently represent an integer of 0 or more, at least one of n and m represents an integer of 1 or more, and R3 and R4 independently represent an alkyl group having one or more hydroxyl groups or hydrogen atoms) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a resin composition in which a plant-derived filler is blended with a thermoplastic resin, as well as uses and a production method thereof. [Background technology]

[0002] Cellulose, a plant-derived fiber, is a sustainable resource with low environmental impact and possesses excellent properties, such as high elastic modulus, high strength, and low linear expansion coefficient. Therefore, it is used in a wide range of applications, including materials for paper, films, and sheets, and composite materials containing polymer components (e.g., as a reinforcing agent for polymer components). In particular, cellulose is added as a reinforcing agent to thermoplastic resins in composite materials to improve their mechanical properties.

[0003] Japanese Patent Laid-Open Publication No. 63-33448 (Patent Document 1) discloses a polyolefin composition containing a polyolefin, a plant fiber mainly composed of fiberized cellulose, and 0.01 to 5 parts by weight of a nucleating agent per 100 parts by weight of the polyolefin and the plant fiber combined. In the examples of this document, aluminum monohydroxy-di-pt-butylbenzoate or 1,3:2,4-dibenzylidene sorbitol is used as the nucleating agent.

[0004] Japanese Patent Laid-Open Publication No. 2019-26658 (Patent Document 2) discloses a method for producing a thermoplastic resin composition containing a thermoplastic resin, amorphized cellulose having a relative crystallinity of less than 50%, and a compatibilizer. This document describes inorganic and organic nucleating agents as nucleating agents, and exemplified one type of organic nucleating agent as a sorbitol derivative such as 1,3:2,4-bis-O-(4-methylbenzylidene)-D-sorbitol. In the examples of this document, no nucleating agent is used.

[0005] Japanese Patent Laid-Open Publication No. 2019-111666 (Patent Document 3) discloses a molded body made of a fiber-reinforced polypropylene resin composition containing a polypropylene resin and cellulose fibers as a resin molded body for attaching a polypropylene decorative film by thermoforming. This document describes nucleating agents that can be blended into the polypropylene resin, such as metal salts of aromatic carboxylic acids, metal salts of aromatic phosphates, sorbitol derivatives, metal salts of rosin, and amide nucleating agents, and gives examples of nucleating agents such as p-methyl-benzylidene sorbitol and p-ethyl-benzylidene sorbitol. In the examples of this document, no nucleating agent is used.

[0006] Japanese Patent Application Laid-Open Publication No. 2020-111689 (Patent Document 4) discloses a resin composition containing a resin containing a 4-methyl-1-pentene-α-olefin copolymer, a compatibilizer, and natural fibers. This document describes a nucleating agent as one type of additive that can be incorporated into the resin composition, and cites a dibenzylidene sorbitol-based nucleating agent as an example of the nucleating agent. In the examples of this document, no nucleating agent is used.

[0007] Japanese Patent Laid-Open Publication No. 2024-38175 (Patent Document 5) discloses a thermoplastic resin composition containing cellulose nanofibers, an alcohol-based compound having 4 to 60 carbon atoms, and a thermoplastic resin. This document describes metal carboxylates, polyol derivatives, and amide compounds as nucleating agents, which are a type of additive that can be incorporated into thermoplastic resin compositions. Examples of polyol derivatives described include dibenzylidene sorbitol, bis(methylbenzylidene)sorbitol, bis(3,4-dimethylbenzylidene)sorbitol, bis(p-ethylbenzylidene)sorbitol, bis(dimethylbenzylidene)sorbitol, and 1,2,3-trideoxy-4,6:5,7-bis-O-((4-propylphenyl)methylene)nonitol. In the examples of this document, no nucleating agent is used. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 63-33448 [Patent Document 2] Japanese Patent Application Publication No. 2019-26658 [Patent Document 3] Japanese Patent Application Publication No. 2019-111666 [Patent Document 4] Japanese Patent Application Publication No. 2020-111689 [Patent Document 5] Japanese Patent Application Laid-Open No. 2024-38175 Summary of the Invention [Problem to be solved by the invention]

[0009] However, even the resin compositions of Patent Documents 1 to 5 did not have sufficient mechanical properties.

[0010] Therefore, an object of the present disclosure is to provide a thermoplastic resin composition containing a plant-derived filler and having high mechanical properties, as well as uses and production methods thereof. [Means for solving the problem]

[0011] As a result of intensive research to achieve the above object, the present inventors have found that a thermoplastic resin composition having high mechanical properties can be provided by combining a thermoplastic resin, a plant-derived filler, and a specific diacetal compound, and have completed the present invention (or the present disclosure).

[0012] That is, the present disclosure includes the following aspects.

[0013] Aspect [1]: A resin composition comprising a thermoplastic resin, a plant-derived filler, and a diacetal compound represented by the following formula (1):

[0014] [ka]

[0015] (In the formula, Z1 and Z 2 each independently represents an arene ring, R 1 and R 2 independently represent an alkyl group, n and m independently represent an integer of 0 or more, and at least one of n and m represents an integer of 1 or more, R 3 and R 4 each independently represents an alkyl group having one or more hydroxyl groups or a hydrogen atom.

[0016] Aspect [2]: In the formula (1), R 3 and R 4 At least one of the C has one or more hydroxyl groups 1-6 The resin composition according to the above aspect [1], wherein the alkyl group is present.

[0017] Aspect [3]: In the formula (1), R 3 and R 4 One of the two is a linear C having two or more hydroxyl groups 2-6 The resin composition according to the above aspect [1] or [2], wherein one of the two groups represents an alkyl group and the other represents a hydrogen atom.

[0018] Aspect [4]: ​​In the formula (1), Z 1 and Z 2 represents a benzene ring, and R 1 and R 2 C 1-3 The resin composition according to any one of the above aspects [1] to [3], wherein n represents an alkyl group, and m independently represents an integer of 1 or more.

[0019] Aspect [5]: The resin composition according to any one of Aspects [1] to [4], comprising 1 to 100 parts by mass of the plant-derived filler and 0.01 to 100 parts by mass of the diacetal compound relative to 100 parts by mass of the thermoplastic resin.

[0020] Aspect [6]: The resin composition according to any one of Aspects [1] to [5], wherein the ratio of the diacetal compound is 1.5 to 20 parts by mass per 100 parts by mass of the thermoplastic resin.

[0021] Aspect [7]: The resin composition according to any one of Aspects [1] to [6], wherein the proportion of the diacetal compound is 20 parts by mass or more per 100 parts by mass of the plant-derived filler.

[0022] Aspect [8]: The resin composition according to any one of Aspects [1] to [7], wherein the plant-derived filler contains cellulose fiber.

[0023] Aspect [9]: The resin composition according to any one of Aspects [1] to [8], wherein the thermoplastic resin contains a polyolefin-based resin.

[0024] Aspect

[10] : The resin composition according to any one of Aspects [1] to [9], wherein the thermoplastic resin comprises a polypropylene-based resin and an acid-modified polyolefin-based resin.

[0025] Aspect

[11] : A method for producing a resin composition according to any one of Aspects [1] to

[10] , comprising a step of kneading the thermoplastic resin, the plant-derived filler, and the diacetal compound represented by Formula (1).

[0026] Aspect

[12] : A molded article formed from the resin composition according to any one of aspects [1] to

[10] , the molded article being a part or material selected from the group consisting of automobile parts, electrical and electronic parts, building materials, civil engineering materials, agricultural materials, packaging materials, household materials, and optical components.

[0027] Aspect

[13] : A strength improver for improving the strength of a resin composition containing a thermoplastic resin and a plant-derived filler, the strength improver comprising a diacetal compound represented by the following formula (1):

[0028] [ka]

[0029] (In the formula, Z 1 and Z 2each independently represents an arene ring, R 1 and R 2 independently represent an alkyl group, n and m independently represent an integer of 0 or more, and at least one of n and m represents an integer of 1 or more, R 3 and R 4 each independently represents an alkyl group having one or more hydroxyl groups or a hydrogen atom.

[0030] Aspect

[14] : A method for improving the mechanical properties of a resin composition comprising a thermoplastic resin and a plant-derived filler by blending a diacetal compound represented by the following formula (1):

[0031] [ka]

[0032] (In the formula, Z 1 and Z 2 each independently represents an arene ring, R 1 and R 2 independently represent an alkyl group, n and m independently represent an integer of 0 or more, and at least one of n and m represents an integer of 1 or more, R 3 and R 4 each independently represents an alkyl group having one or more hydroxyl groups or a hydrogen atom.

[0033] In addition, the present disclosure may achieve the following secondary objectives (solve the problems).

[0034] Another object of the present disclosure is to provide a strength improver that can improve the strength of a resin composition containing a thermoplastic resin and a plant-derived filler, and a method for improving the mechanical properties of the resin composition.

[0035] In this specification and claims, the number of carbon atoms in a substituent or the like is expressed as C1, C6, C 10For example, "C1 alkyl group" means an alkyl group with 1 carbon atom, and "C 6-10 The term "aryl group" refers to an aryl group having 6 to 10 carbon atoms.

[0036] In addition, in the present specification and claims, the term "independently" means that two components are independent of each other. For example, an alkyl group R 1 and R 2 In the case of R 1 and R 2 This means that the alkyl groups and the alkyl groups do not have to be the same, but may be different.

[0037] Furthermore, in this specification and claims, when a numerical range is indicated using "X to Y", the extreme numerical values ​​X and Y may be included. [Effects of the Invention]

[0038] According to the present disclosure, a thermoplastic resin composition having high mechanical properties (strength, elastic modulus, etc.) can be provided by using a plant-derived filler. DETAILED DESCRIPTION OF THE INVENTION

[0039] [Thermoplastic resin] The resin composition (thermoplastic resin composition) of the present disclosure contains a thermoplastic resin.

[0040] Examples of thermoplastic resins include polyolefin resins such as chain olefin resins and cyclic olefin resins; styrene resins such as polystyrene, styrene-methyl methacrylate copolymer (MS resin), styrene-acrylonitrile copolymer (AS resin), high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), and methyl methacrylate-butadiene-styrene copolymer (MBS resin); and polymethyl methacrylate (PMMA), (meth)acrylic acid-(meth)acrylic acid ester copolymers. (Meth)acrylic resins; vinyl acetate resins such as polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), and polyvinyl acetal (polyvinyl formal (PVF), polyvinyl butyral (PVB), etc.); vinyl chloride homopolymer (PVC); vinyl chloride resins such as vinyl chloride-vinyl acetate copolymers; vinylidene chloride resins such as vinylidene chloride-vinyl chloride copolymers and vinylidene chloride-acrylonitrile copolymers; fluororesins such as polytetrafluoroethylene (PTFE); polyalkylene arylate resins, polyhydroxycarbonate Polyester-based resins such as carboxylic acid-based resins, polyarylate-based resins, liquid crystal polyesters (LCP), and bisphenol-based (e.g., bisphenol A-type) polycarbonate-based resins; polyamide-based resins such as aliphatic polyamide resins, aromatic polyamide resins, or aramid resins; polyacetal-based resins such as polyacetal resins (POM); polyphenylene ether-based resins such as polyphenylene ether (PPE); polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ether ketone ketone (PEKEK) Polyetherketone resins such as polyetherketone (K); phenoxy resins; polyketone resins such as aliphatic polyketone resins; polyphenylene sulfide resins such as polyphenylene sulfide (PPS); polysulfone resins such as polysulfone (PSF) and polyethersulfone (PES); cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate propionate; cellulose ethers such as ethyl cellulose; thermoplastic polyimide resins such as polyetherimide (PEI) and polyamideimide; polyethernitrile resins;Examples of thermoplastic elastomers (TPEs) include polystyrene-based thermoplastic elastomers, polyolefin-based TPEs (TPOs), polydiene-based TPEs, chlorine-based TPEs, fluorine-based TPEs, polyurethane-based TPEs (TPUs), polyester-based TPEs (TPEEs), and polyamide-based TPEs (TPAs). These thermoplastic resins can be used alone or in combination.

[0041] The density of the thermoplastic resin is, for example, 0.85 to 3 g / cm 3 The density may be selected from a range of about 0.9 to 2.7 g / cm 3 , preferably 0.9 to 2 g / cm 3 , and more preferably 0.9 to 1.5 g / cm 3 may be.

[0042] The weight-average molecular weight Mw of the thermoplastic resin may be selected, for example, from the range of about 10,000 to 10,000,000. The number-average molecular weight Mn may be selected, for example, from the range of about 13,000 to 1,000,000, preferably 15,000 to 800,000, more preferably 18,000 to 500,000, and even more preferably 20,000 to 400,000. The molecular weight distribution (Mw / Mn) may be selected, for example, from the range of about 1 to 50, and is preferably 2 to 25.

[0043] In the present specification and claims, the weight average molecular weight, number average molecular weight and molecular weight distribution can be measured by GPC in terms of standard polystyrene.

[0044] Among these thermoplastic resins, polyolefin resins, polyester resins, and polyamide resins are particularly preferred because the combination of a vegetable filler and a compound represented by formula (1) can effectively improve mechanical properties.

[0045] (Polyolefin resin) Polyolefin resins are α-chain C polymers such as ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene.2-12 It is sufficient that the α-chain C copolymer contains an olefin unit derived from an olefin, and it may contain other copolymerizable units in addition to the olefin unit. 2-12 Olefins include α-C such as ethylene, propylene, 1-butene, and 4-methyl-pentene-1. 2-6 Olefins are preferred, with ethylene and / or propylene being particularly preferred.

[0046] Examples of polymerization components (copolymerizable monomers) for forming other copolymerizable units include aromatic vinyls such as styrene; aliphatic vinyl esters such as vinyl acetate and vinyl propionate; unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, and angelic acid; and (meth)acrylic acid Cs such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate. 1-10 Alkyl ester, (meth)acrylic acid hydroxy C 1-10 (Meth)acrylic acid esters such as alkyl esters and glycidyl (meth)acrylate; (meth)acrylic acid amides; (meth)acrylonitrile; unsaturated dicarboxylic acids or anhydrides such as maleic acid (anhydride), fumaric acid, citraconic acid (anhydride), itaconic acid (anhydride), and mesaconic acid; unsaturated dicarboxylic acid di-C such as dimethyl maleate, diethyl maleate, and dibutyl maleate. 1-10 Examples of the copolymerizable monomer include alkyl esters and diene monomers such as butadiene and isoprene. These copolymerizable monomers can be used alone or in combination. The molar ratio of the olefin unit to the other copolymerizable unit is, for example, 50 / 50 to 100 / 0, preferably 70 / 30 to 100 / 0, and more preferably 90 / 10 to 100 / 0 (former / latter).

[0047] As the polyolefin resin, polyethylene resin, polypropylene resin, and acid-modified polyolefin resin are preferred.

[0048] The polyethylene resin may be a polyolefin resin containing ethylene units as the main units (for example, units containing 50 mol % or more, preferably 80 mol % or more, and more preferably 90 mol % or more).

[0049] Examples of polyethylene-based resins include ethylene homopolymers such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and ultra-high molecular weight polyethylene; and copolymers based on ethylene, such as ethylene-propylene copolymers, ethylene-butene-1 copolymers, ethylene-propylene-butene-1 copolymers, ethylene-(4-methylpentene-1) copolymers, ethylene-vinyl acetate copolymers (EVA resins), and ethylene-methyl methacrylate copolymers. These polyethylene-based resins can be used alone or in combination. Among these polyethylene-based resins, medium-density or high-density polyethylenes are preferred, with HDPE being particularly preferred, due to their excellent mechanical properties, such as flexural strength and flexural modulus.

[0050] The density of polyethylene resin is 0.910 to 0.980 kg / m according to JIS K 6922-1. 3 The range can be selected from, for example, 0.930 to 0.970 kg / m due to its excellent mechanical properties. 3 , preferably 0.940 to 0.965 kg / m 3 , and more preferably 0.950 to 0.962 kg / m 3 , more preferably 0.955 to 0.960 kg / m 3 is.

[0051] The melt mass flow rate (MFR) of the polyethylene resin is, in accordance with JIS K 6922-2, for example, 3 to 80 g / 10 min, preferably 5 to 50 g / 10 min, further preferably 10 to 30 g / 10 min, and even more preferably 15 to 25 g / 10 min. If the MFR is equal to or higher than the lower limit, the melt moldability of the resin composition tends to be improved, whereas if it is equal to or lower than the upper limit, the mechanical properties of the resin composition tend to be improved.

[0052] The melting point (DSC method) of the polyethylene resin, in accordance with ISO 11357-3, is, for example, 80 to 150° C., preferably 100 to 145° C., further preferably 120 to 140° C., and even more preferably 130 to 135° C. If the melting point is equal to or higher than the lower limit, the heat resistance of the resin composition tends to be improved, and if it is equal to or lower than the upper limit, the melt moldability of the resin composition tends to be improved.

[0053] The polypropylene resin may contain propylene units as the main units (for example, units contained in an amount of 50 mol % or more, preferably 80 mol % or more, and more preferably 90 mol % or more).

[0054] Examples of polypropylene resins include propylene homopolymers such as isotactic polypropylene (NZ catalyst-based or metallocene catalyst-based polypropylene), syndiotactic polypropylene, and atactic polypropylene; propylene-ethylene copolymers, propylene-C 4-6 Examples of suitable polypropylene resins include copolymers containing propylene as a main component, such as alkene copolymers (e.g., propylene-butene copolymers). These polypropylene resins can be used alone or in combination of two or more. Among these polypropylene resins, polypropylene resins containing propylene homopolymers are preferred, and propylene homopolymers are particularly preferred.

[0055] The polypropylene-based resin may be a block polypropylene. The block polypropylene may be a mixture of a propylene homopolymer and a propylene-ethylene copolymer, and in particular, may be a mixture having a sea-island structure consisting of a continuous phase formed of a propylene homopolymer and a dispersed phase containing a propylene-ethylene copolymer. Furthermore, the dispersed phase may be a dispersed phase consisting of a surface layer formed of a propylene-ethylene copolymer distributed at the interface with the continuous phase, and an inner layer formed of an ethylene homopolymer.

[0056] The ethylene content in the block polypropylene is, for example, 0.01 to 50% by mass, preferably 0.1 to 30% by mass, and more preferably 1 to 10% by mass.

[0057] The density of polypropylene resin is 0.855 to 0.940 kg / m according to JIS K 7112. 3 In view of the excellent mechanical properties of the resin composition, for example, 0.870 to 0.930 kg / m 3 , preferably 0.880 to 0.925 kg / m 3 , and more preferably 0.890 to 0.920 kg / m 3 , more preferably 0.900 to 0.915 kg / m 3 is.

[0058] The melt mass flow rate (MFR) of the polypropylene resin is, for example, 1 to 100 g / 10 min, preferably 3 to 50 g / 10 min, further preferably 4 to 30 g / 10 min, further preferably 5 to 20 g / 10 min, and most preferably 8 to 15 g / 10 min, according to JIS K 7210 (test temperature: 230°C, test load: 2.16 kg). If the MFR is equal to or higher than the lower limit, the melt moldability of the resin composition tends to be improved, whereas if it is equal to or lower than the upper limit, the mechanical properties of the resin composition tend to be improved.

[0059] The tensile modulus of the polypropylene resin is, for example, 1000 to 2500 MPa, preferably 1200 to 2000 MPa, further preferably 1400 to 1900 MPa, even more preferably 1500 to 1800 MPa, and most preferably 1600 to 1700 MPa, in accordance with JIS K 7161. When the tensile modulus of the resin composition is equal to or higher than the lower limit, the mechanical properties of the resin composition tend to be improved, whereas when it is equal to or lower than the upper limit, the melt moldability of the resin composition tends to be improved.

[0060] The Charpy impact strength (23°C) of polypropylene resins is, for example, 1 to 50 kJ / m according to JIS K 7111. 2 , preferably 1.5 to 30 kJ / m 2 , more preferably 2 to 10 kJ / m2 , more preferably 2.5 to 7 kJ / m 2 , most preferably 3 to 5 kJ / m 2 When the Charpy impact strength is equal to or higher than the lower limit, the melt formability tends to be improved, and when it is equal to or lower than the upper limit, the balance of the elastic modulus, strength, etc. tends to be excellent.

[0061] The deflection temperature under load (heat distortion temperature) of the polypropylene resin, according to JIS K 7191 (bending stress: Method B 0.45 MPa), is, for example, 60 to 150°C, preferably 70 to 130°C, further preferably 80 to 120°C, even more preferably 90 to 110°C, and most preferably 95 to 105°C. If the deflection temperature under load is equal to or higher than the lower limit, the heat resistance of the resin composition tends to be improved, and if the deflection temperature under load is equal to or lower than the upper limit, the melt moldability of the resin composition tends to be improved.

[0062] The acid-modified polyolefin resin may be a polyolefin resin modified with a carboxylic acid, specifically a polyolefin resin having a carboxyl group and / or an acid anhydride group. The acid-modification method is not particularly limited as long as a carboxyl group and / or an acid anhydride group is introduced into the skeleton of an unmodified polyolefin resin, but from the viewpoint of mechanical properties, a method of introducing a monomer having a carboxyl group and / or an acid anhydride group by copolymerization is preferred. The copolymerization may be in the form of random copolymerization or block copolymerization, but graft copolymerization is preferred.

[0063] The unmodified polyolefin resin may be any of the α-chain C polyolefin resins exemplified above. 2-12 Among the unmodified polyolefin resins, polyethylene resins such as polyethylene and polypropylene resins such as polypropylene are preferred, with polypropylene resins being particularly preferred.

[0064] Examples of monomers having a carboxyl group and / or anhydride group include the unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, and acid anhydrides exemplified above as copolymerizable monomers for polyolefin resins. These monomers can be used alone or in combination. Among these monomers, unsaturated monocarboxylic acids such as (meth)acrylic acid, unsaturated dicarboxylic acids such as maleic anhydride, or acid anhydrides thereof are preferred, with maleic anhydride being particularly preferred.

[0065] As the acid-modified polyolefin resin, an acid-modified polypropylene resin is preferred, and maleic anhydride-modified polypropylene is particularly preferred.

[0066] In the acid-modified polyolefin resin, the proportion of the monomer can be selected from a range of about 0.01 to 30 parts by mass relative to 100 parts by mass of the unmodified polyolefin resin, for example, 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass, more preferably 0.3 to 8 parts by mass, and even more preferably 0.5 to 5 parts by mass.

[0067] The acid value (mgKOH / g) of the acid-modified polyolefin resin, in accordance with JIS K 2510, is, for example, 10 to 100, preferably 20 to 80, further preferably 30 to 50, and even more preferably 35 to 45. When the acid value is equal to or higher than the lower limit, the mechanical properties of the resin composition tend to be improved, and when it is equal to or lower than the upper limit, the melt moldability of the resin composition tends to be improved.

[0068] The viscosity (melt viscosity at 180°C) of the acid-modified polyolefin resin is, for example, 0.5 to 50 Pa·s, preferably 1 to 30 Pa·s, further preferably 1.5 to 10 Pa·s, even more preferably 2 to 5 Pa·s, and most preferably 3 to 4 Pa·s, in accordance with JIS K 6862. If the viscosity is equal to or higher than the lower limit, the mechanical properties of the resin composition tend to be improved, whereas if the viscosity is equal to or lower than the upper limit, the melt moldability of the resin composition tends to be improved.

[0069] The polyolefin resin preferably contains at least a polyethylene resin and / or a polypropylene resin, as this can improve mechanical properties, and a polyethylene resin alone or a combination of a polypropylene resin (particularly a propylene homopolymer) and an acid-modified polyolefin resin is particularly preferred.

[0070] When a polypropylene resin and an acid-modified polyolefin resin (particularly an acid-modified polypropylene resin) are combined as the polyolefin resin, the proportion of the acid-modified polyolefin resin is, for example, 0.1 to 100 parts by mass, preferably 1 to 50 parts by mass, more preferably 2 to 30 parts by mass, more preferably 3 to 10 parts by mass, and most preferably 5 to 8 parts by mass, per 100 parts by mass of the polypropylene resin. If the proportion of the acid-modified polyolefin resin is equal to or greater than the lower limit, the mechanical properties of the resin composition tend to be improved, whereas if it is equal to or less than the upper limit, the melt moldability of the resin composition tends to be improved.

[0071] When the thermoplastic resin contains a polyolefin-based resin, the proportion of the polyolefin-based resin in the thermoplastic resin may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass. When the proportion of the polyolefin-based resin is equal to or greater than the lower limit, the moldability and mechanical properties of the resin composition tend to be improved.

[0072] (Polyester resin) Examples of polyester resins include polyesters obtained by reacting (condensation reaction) a diol component with a dicarboxylic acid component, and polyesters obtained by reacting (condensation reaction) a hydroxycarboxylic acid.

[0073] Examples of the diol component include aliphatic diols such as alkanediols and polyalkanediols; alicyclic diols such as cycloalkanediols, di(hydroxyalkyl)cycloalkanes, and alkylene oxide (alkylene carbonate or haloalkanol) adducts thereof; and aromatic diols such as dihydroxyarenes, aromatic aliphatic diols, bisphenols, and alkylene oxide adducts thereof.

[0074] Alkanediols include C alkanediols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1,3-butanediol, 1,4-pentanediol, 1,5-pentanediol, 1,3-pentanediol, and neopentyl glycol. 2-10 Alkanediols and the like.

[0075] The polyalkanediols include di- and tri-C such as diethylene glycol, dipropylene glycol, and triethylene glycol. 2-4 Alkanediols and the like.

[0076] Cycloalkanediols include C 5-8 Cycloalkanediols and the like.

[0077] Di(hydroxyalkyl)cycloalkanes include di(hydroxy C) such as cyclopentane dimethanol and cyclohexane dimethanol. 1-4 Alkyl)C 5-8 Cycloalkanes and the like.

[0078] Dihydroxyarenes include hydroquinone, resorcinol, and biphenol.

[0079] Aromatic aliphatic diols include di(hydroxy C) such as 1,4-benzenedimethanol and 1,3-benzenedimethanol. 1-4 Alkyl)C 6-10arenes, etc.

[0080] Bisphenols include bis(hydroxyphenyl) C, such as bisphenol A. 1-10 Alkanes and the like.

[0081] These diol components can be used alone or in combination. Among these diol components, C olefins such as ethylene glycol and 1,4-butanediol are preferred. 2-6 Alkanediols are preferred, C 2-5 Alkanediols are more preferred, C 3-5 Alkanediols are more preferred.

[0082] Examples of the dicarboxylic acid component include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic carboxylic acids, and derivatives of these dicarboxylic acids.

[0083] Examples of aliphatic dicarboxylic acids include alkanedicarboxylic acids, such as adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. 2-20 Alkane-dicarboxylic acids and the like.

[0084] Alicyclic dicarboxylic acids include cycloalkane dicarboxylic acids, di- and tricycloalkane dicarboxylic acids, etc. Examples of cycloalkane dicarboxylic acids include C cyclohexane dicarboxylic acids, etc. 5-10 Examples of di- or tricycloalkanedicarboxylic acids include decalindicarboxylic acid, norbornanedicarboxylic acid, and adamantanedicarboxylic acid.

[0085] Examples of aromatic dicarboxylic acids include arene dicarboxylic acids, biphenyl dicarboxylic acids, diphenylalkane dicarboxylic acids, diphenyl ketone dicarboxylic acids, and diphenyl ether dicarboxylic acids. Examples of arene dicarboxylic acids include C carboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, anthracene dicarboxylic acid, and phenanthrene dicarboxylic acid. 6-14 Examples of diphenyl dicarboxylic acids include 2,2'-biphenyl dicarboxylic acid and 4,4'-biphenyl dicarboxylic acid. Examples of diphenyl alkane dicarboxylic acids include diphenyl C dicarboxylic acids such as 4,4'-diphenylmethane dicarboxylic acid and 2,2-di(4-carboxyphenyl)hexafluoropropane. 1-10 Examples of diphenyl ketone dicarboxylic acids include 4,4'-diphenyl ketone dicarboxylic acid, and examples of diphenyl ether dicarboxylic acids include 4,4'-diphenyl ether dicarboxylic acid.

[0086] Examples of the derivatives of dicarboxylic acids include dicarboxylic acid halides such as dicarboxylic acid chlorides; dicarboxylic acid anhydrides; and dicarboxylic acid lower alkyl esters such as dicarboxylic acid methyl esters and dicarboxylic acid ethyl esters. The lower alkyl esters are C 1-4 Alkyl esters are preferred, C 1-2 Alkyl esters are particularly preferred.

[0087] These dicarboxylic acid components can be used alone or in combination. Among these dicarboxylic acid components, cycloalkane-dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; arene-dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid are preferred, and C 6-10 Arene-dicarboxylic acids are particularly preferred.

[0088] Examples of the hydroxycarboxylic acid component include glycolic acid, lactic acid, and hydroxybutyric acid.

[0089] Among these polyester resins, polyalkylene arylate resins such as polyalkylene terephthalate resins and polyalkylene naphthalate resins are preferred in terms of mechanical properties and heat resistance.

[0090] The polyalkylene arylate resins include those having alkylene arylate units (especially C such as ethylene terephthalate, butylene terephthalate, and ethylene-2,6-naphthalate). 2-6 Examples of the copolymerizable monomers constituting the copolyester include homopolyesters of alkylene arylate units, and copolyesters having an alkylene arylate unit content of, for example, 50 mol % or more, preferably 80 mol % or more (particularly 90 mol % or more). Examples of copolymerizable monomers constituting the copolyester include the above-mentioned dicarboxylic acid components and diol components, as well as hydroxycarboxylic acid components such as hydroxybenzoic acid and lactone components such as caprolactone. Among these copolymerizable monomers, dicarboxylic acid components such as isophthalic acid are commonly used.

[0091] Representative polyalkylene arylate resins include polyC such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. 2-10 Alkylene C 8-16 arylate; poly-C such as poly-1,4-cyclohexanedimethylene terephthalate 5-10 Cycloalkane-diC 1-4 Alkylene C 8-16 Examples include arylates.

[0092] These polyalkylene arylate resins can be used alone or in combination. Among these, polyC such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate are preferred. 2-6 Alkylene C 8-16 Arylate is preferred, and poly(C) such as polybutylene terephthalate. 3-5 Alkylene C 8-12 The arylates are particularly preferred.

[0093] These polyester resins may be crystalline like polyalkylene arylate resins, amorphous like polyarylate resins, or transparent polyester resins (amorphous transparent polyester resins). The crystallinity of the polyester resin can also be adjusted by the copolymerization components described above. For example, the crystallinity may be adjusted by using an asymmetric aliphatic diol component such as propylene glycol or 1,3-butanediol; or an asymmetric aromatic dicarboxylic acid component such as phthalic acid or isophthalic acid.

[0094] The density of polyester resins is 0.95 to 1.8 g / cm according to ISO 1183. 3 In view of the excellent mechanical properties of the resin composition, for example, 1 to 1.75 g / cm 3 , preferably 1 to 1.7 g / cm 3 , and more preferably 1.1 to 1.5 g / cm 3 , more preferably 1.2 to 1.4 g / cm 3 is.

[0095] The melt volume flow rate (MVR) of polyester resins is, for example, 5 to 100 cm, in accordance with ISO 1133 (test temperature: 250°C, test load: 2.16 kg). 3 / 10 minutes, preferably 10-50cm 3 / 10 minutes, more preferably 15 to 40 cm 3 / 10 minutes, preferably 20-30cm 3 When the MVR is equal to or higher than the lower limit, the melt moldability of the resin composition tends to be improved, and when it is equal to or lower than the upper limit, the mechanical properties of the resin composition tend to be improved.

[0096] The weight average molecular weight of the polyester resin can be selected from a range of about 3,000 to 1,000,000, based on an evaluation method using gel permeation chromatography with polystyrene as the standard, and is, for example, 5,000 to 800,000, preferably 8,000 to 600,000, further preferably 10,000 to 500,000, and even more preferably 20,000 to 500,000.

[0097] The glass transition temperature (Tg) of the polyester resin is, for example, 30 to 350°C, preferably 40 to 300°C, further preferably 40 to 250°C, and even more preferably 40 to 200°C.

[0098] When the thermoplastic resin contains a polyester-based resin, the proportion of the polyester-based resin in the thermoplastic resin may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass. When the proportion of the polyester-based resin is equal to or greater than the lower limit, the moldability and mechanical properties of the resin composition tend to be improved.

[0099] (Polyamide resin) The polyamide-based resin may be formed from at least one selected from the group consisting of an aliphatic monomer component, an alicyclic monomer component, and an aromatic monomer component. Among these, it is preferable to contain an aliphatic monomer component, and an aliphatic monomer component is particularly preferable.

[0100] In the present specification and claims, the monomer component having a carboxyl group such as a dicarboxylic acid described later may be an acid halide such as an acid chloride, or an amide-forming derivative such as an acid anhydride.

[0101] Examples of the aliphatic monomer component include aliphatic diamines, aliphatic dicarboxylic acids, aliphatic aminocarboxylic acids, and lactams.

[0102] Examples of aliphatic diamines include linear or branched C diamines such as tetramethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, 2-methyloctamethylenediamine, trimethylhexamethylenediamine, decamethylenediamine, and dodecamethylenediamine. 2-20 Among these, linear or branched C alkylene diamines are 4-16 Alkylenediamines are preferred, and linear or branched C 6-12 Alkylenediamines are particularly preferred.

[0103] Examples of the aliphatic dicarboxylic acid include saturated aliphatic dicarboxylic acids (straight-chain or branched-chain alkane dicarboxylic acids) and unsaturated aliphatic dicarboxylic acids.

[0104] The linear or branched alkanedicarboxylic acids include linear or branched C alkanedicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and 1,10-decanedicarboxylic acid. 1-20 Alkane-dicarboxylic acids, etc. Among these, linear or branched C 2-16 Alkane-dicarboxylic acids are preferred, and linear or branched C alkane-dicarboxylic acids such as adipic acid, sebacic acid, and 1,10-decanedicarboxylic acid are preferred. 4-12 Alkane-dicarboxylic acids are particularly preferred.

[0105] Unsaturated aliphatic dicarboxylic acids include C such as maleic acid, fumaric acid, and itaconic acid. 2-10 Alkene-dicarboxylic acids and the like.

[0106] Aliphatic aminocarboxylic acids include amino C such as 6-aminohexanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. 2-20 Among these, amino C 3-16 Alkyl-carboxylic acids are preferred, amino C 5-11 Alkyl-carboxylic acids are particularly preferred.

[0107] The lactam may be a lactam corresponding to the aliphatic aminocarboxylic acid, and examples thereof include lactams having 4 to 13 membered rings such as ε-caprolactam, ω-laurolactam, etc. Among these, lactams having 7 to 13 membered rings are preferred.

[0108] The alicyclic monomer component may be any monomer having an alicyclic skeleton (or an aliphatic hydrocarbon ring skeleton), and examples thereof include alicyclic diamines, alicyclic dicarboxylic acids, and alicyclic aminocarboxylic acids.

[0109] Examples of the alicyclic diamine include diaminocycloalkanes, bis(aminoalkyl)cycloalkanes, and bis(aminocyclohexyl)alkanes.

[0110] Examples of diaminocycloalkanes include diamino C such as diaminocyclohexane. 5-10 Cycloalkanes and the like.

[0111] Bis(aminoalkyl)cycloalkanes include bis(amino C) such as bis(aminomethyl)cyclohexane. 1-4 Alkyl)C 5-10 Cycloalkanes and the like.

[0112] Bis(aminocyclohexyl)alkanes include bis(aminocyclohexyl) C such as bis(4-aminocyclohexyl)methane and 2,2-bis(4-aminocyclohexyl)propane. 1-6 Alkanes; bis(amino-mono to tri C) such as bis(4-amino-3-methylcyclohexyl)methane, bis(4-amino-3,5-dimethylcyclohexyl)methane, and 2,2-bis(4-amino-3-methylcyclohexyl)propane 1-6 Alkyl-C 5-10 Cycloalkyl)C 1-6 Alkanes and the like.

[0113] Examples of the alicyclic dicarboxylic acid include the alicyclic dicarboxylic acids exemplified as the alicyclic dicarboxylic acid of the dicarboxylic acid component in the polyester resin section.

[0114] Examples of alicyclic aminocarboxylic acids include aminocycloalkanecarboxylic acids, and specifically, amino C such as aminocyclohexanecarboxylic acids. 5-10 Examples include cycloalkane-carboxylic acids.

[0115] The aromatic monomer component may have an aromatic ring skeleton, and examples thereof include aromatic (or araliphatic) diamines, aromatic (or araliphatic) dicarboxylic acids, and aromatic (or araliphatic) aminocarboxylic acids.

[0116] Examples of aromatic (or aromatic aliphatic) diamines include diaminoarenes, bis(aminoalkyl)arenes, etc. Diaminoarenes include diamino C arenes such as m-phenylenediamine and p-phenylenediamine. 6-14 Examples of bis(aminoalkyl)arenes include bis(amino C) such as m-xylylenediamine. 1-4 alkyl)arenes.

[0117] Examples of the aromatic (or aromatic aliphatic) dicarboxylic acid include the aromatic dicarboxylic acids exemplified as the aromatic dicarboxylic acid component in the polyester resin section.

[0118] Examples of aromatic aminocarboxylic acid components include aminoarenecarboxylic acids, such as amino C such as aminobenzoic acid. 6-12 arene-carboxylic acids.

[0119] Polyamide-based resins can be formed by using these monomer components alone or in combination. For example, they may be formed by polymerization of a diamine component and a dicarboxylic acid component, polymerization of an aminocarboxylic acid component and / or a lactam component, or polymerization of a diamine component and a dicarboxylic acid component with an aminocarboxylic acid component and / or a lactam component. Furthermore, polyamide-based resins may be homopolyamides formed from a single monomer component (a single diamine component and a dicarboxylic acid component, a single aminocarboxylic acid component, or a single lactam component), or copolyamides in which multiple monomer components are copolymerized. Representative polyamide-based resins include aliphatic polyamide resins, alicyclic polyamide resins, and aromatic polyamide resins. Of these, aliphatic polyamide resins are preferred.

[0120] The aliphatic polyamide resin may be formed from aliphatic monomer units derived from aliphatic monomer components. Examples of the aliphatic polyamide resin include homopolyamides of aliphatic diamines and aliphatic dicarboxylic acids, such as polyamide 46, polyamide 66, polyamide 610, and polyamide 612; homopolyamides of aliphatic aminocarboxylic acids and / or corresponding lactams, such as polyamide 6, polyamide 11, and polyamide 12; and copolymers (copolyamides) of multiple aliphatic monomer components, such as copolyamide 6 / 66, copolyamide 6 / 11, and copolyamide 66 / 12.

[0121] In this specification and claims, the " / " in copolyamide means that the copolyamide is formed from the monomers (units) before and after it as copolymerization components (copolymerization units). In other words, copolyamide 6 / 66 means a copolymer having units that form polyamide 6 and units that form polyamide 66.

[0122] The aliphatic polyamide resin is preferably an aliphatic polyamide resin containing an aliphatic monomer component having an alkylene group with a carbon number of, for example, 4 to 12, preferably 6 to 11, and more preferably 6 to 9. Typical preferred aliphatic polyamide resins include homopolyamides of aliphatic diamines and aliphatic dicarboxylic acids, such as polyamide 46, polyamide 66, polyamide 610, and polyamide 612; and homopolyamides of aliphatic aminocarboxylic acids and / or the corresponding lactams, such as polyamide 6.

[0123] The density of polyamide resins is 0.95 to 1.8 g / cm according to ISO 1183. 3 In view of the excellent mechanical properties of the resin composition, for example, 1 to 1.7 g / cm 3 , preferably 1 to 1.5 g / cm 3 , and more preferably 1.05 to 1.3 g / cm 3 , more preferably 1.1 to 1.2 g / cm 3 is.

[0124] The melt volume flow rate (MVR) of polyamide resins is, for example, 10 to 400 cm, in accordance with ISO 1133 (test temperature: 275°C, test load: 5 kg). 3 / 10 minutes, preferably 50-350cm 3 / 10 minutes, more preferably 100 to 300 cm 3 / 10 minutes, preferably 150-250cm 3 When the MVR is equal to or higher than the lower limit, the melt moldability of the resin composition tends to be improved, and when the MVR is equal to or lower than the upper limit, the mechanical properties of the resin composition tend to be improved.

[0125] The number average molecular weight Mn of the polyamide resin can be selected from a range of about 7,000 to 1,000,000, for example, 10,000 to 750,000, preferably 15,000 to 500,000, further preferably 18,000 to 500,000, and even more preferably 20,000 to 500,000, based on an evaluation method using gel permeation chromatography with polystyrene as the standard.

[0126] When the thermoplastic resin contains a polyamide-based resin, the proportion of the polyamide-based resin in the thermoplastic resin may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass. When the proportion of the polyamide-based resin is equal to or greater than the lower limit, the moldability and mechanical properties of the resin composition tend to be improved.

[0127] (Preferred aspects and proportions of thermoplastic resin) The thermoplastic resin preferably contains a polyolefin-based resin, more preferably a polypropylene-based resin, and even more preferably a combination of a polypropylene-based resin (particularly a propylene homopolymer) and an acid-modified polyolefin-based resin, since the mechanical properties of the resin composition can be easily improved by incorporating a diacetal compound.

[0128] When the thermoplastic resin contains a combination of a polypropylene resin (particularly a propylene homopolymer) and an acid-modified polyolefin resin, the total amount of the polypropylene resin and the acid-modified polyolefin resin in the thermoplastic resin may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass. When the proportion of the total amount is equal to or greater than the lower limit, the mechanical properties of the resin composition tend to be improved.

[0129] When the polyolefin resin contains a combination of a polypropylene resin (particularly a propylene homopolymer) and an acid-modified polyolefin resin, the total amount of the polypropylene resin and the acid-modified polyolefin resin in the polyolefin resin may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass. When the proportion of the total amount is equal to or greater than the lower limit, the mechanical properties of the resin composition tend to be improved.

[0130] [Plant-derived filler] The plant-derived filler is not particularly limited as long as it is a filler (a bulking agent, a reinforcing agent, or a strengthening agent) made from a plant.

[0131] Examples of the shape of the plant-derived filler include non-fibrous shapes (spherical, approximately spherical, ellipsoidal, polygonal or polyhedral, flat, rod-shaped or columnar, irregularly shaped granular shapes, etc.), fibrous shapes, etc. Of these, fibrous shapes are preferred.

[0132] Examples of plant raw materials include wood, herbs, seed hairs, bamboo, sugarcane, etc. Examples of wood include conifers such as pine, fir, spruce, hemlock, and cedar; and broad-leaved trees such as beech, birch, poplar, and maple. Examples of herbs include hemp, flax, Manila hemp, ramie, and other hemp species; straw; bagasse; and Mitsumata. Examples of seed hairs include cotton linter, bombax cotton, and kapok.

[0133] The plant raw material may be waste paper, straw, food residue, etc. Examples of food residue include tea extract residue, coffee bean extract residue, grain husks, citrus peels, sugarcane residue, and bean skins.

[0134] These plant materials can be used alone or in combination. The plant material is preferably pulp with a low content of non-cellulose components such as lignin and hemicellulose. Commonly used pulps include wood pulp such as softwood pulp and hardwood pulp, and seed fiber pulp such as cotton linter pulp.

[0135] The plant-derived filler is preferably formed from these plant materials, and cellulose fiber (fibrous cellulose) is particularly preferred.

[0136] The cellulose fibers may be highly crystalline, and the degree of crystallinity of the cellulose fibers is, for example, 40 to 100% (e.g., 50 to 100%), preferably 60 to 100%, more preferably 70 to 100%, and most preferably 75 to 99%. The degree of crystallinity is usually 60% or more (e.g., 60 to 98%). The crystalline structure of the cellulose fibers can be, for example, type I, type II, type III, or type IV, and type I crystal structure is preferred because of its excellent linear expansion properties and elastic modulus.

[0137] In this specification and claims, the crystallinity of cellulose fibers can be measured using a powder X-ray diffractometer ("Ultima IV" manufactured by Rigaku Corporation) or the like.

[0138] The cellulose fibers may contain non-cellulose components such as hemicellulose and lignin, and the proportion of the non-cellulose components in the cellulose fibers is 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less. The cellulose fibers may be cellulose fibers that are substantially free of non-cellulose components (particularly, cellulose fibers that do not contain non-cellulose components).

[0139] The cellulose fibers may be high-purity cellulose fibers, and the purity of the cellulose fibers (cellulose purity) may be, for example, 50% by mass or more, preferably 60% by mass or more, further preferably 70% by mass or more, even more preferably 75% by mass or more, and most preferably 80% by mass or more (for example, about 80 to 99% by mass). When the purity of the cellulose fibers is equal to or higher than the lower limit, the mechanical properties of the resin composition tend to be improved.

[0140] In this specification and claims, the purity of cellulose fibers can be measured by the amount of alpha cellulose according to TAPPI T 203.

[0141] The cellulose fibers may be modified or unmodified, preferably unmodified.

[0142] The degree of polymerization of the cellulose fibers may be 500 or more, preferably 600 or more (for example, 600 to 100,000) from the viewpoint of the mechanical properties of the composition.

[0143] The average fiber diameter of the cellulose fibers may be 0.5 to 100 μm, but is preferably on the order of microns, for example, 1 to 80 μm, preferably 5 to 70 μm, more preferably 10 to 50 μm, and most preferably 30 to 45 μm. If the average fiber diameter is equal to or greater than the lower limit, the cellulose fibers tend to be more easily dispersed uniformly in the thermoplastic resin, while if it is equal to or less than the upper limit, it tends to be possible to prevent the cellulose fibers from protruding from the surface of the resin composition, thereby reducing the appearance.

[0144] The average fiber length of the cellulose fibers can be selected from a range of about 1 μm or more (e.g., 1 μm to 100 mm), for example, 10 μm or more (e.g., 0.01 to 50 mm), preferably 100 μm or more (e.g., 0.1 to 30 mm), further preferably 300 μm or more (e.g., 0.3 to 20 mm), more preferably 500 μm or more (e.g., 0.5 to 10 mm), and most preferably 1 mm or more (e.g., 1 to 5 mm). If the average fiber length is equal to or greater than the lower limit, mechanical properties tend to be improved, while if it is equal to or less than the upper limit, the cellulose fibers tend to be more easily dispersed uniformly in the resin composition.

[0145] The ratio of the average fiber length to the average fiber diameter of the cellulose fibers (aspect ratio) is, for example, 5 or more (e.g., 5 to 10,000), preferably 10 or more (e.g., 10 to 5,000), further preferably 15 or more (e.g., 15 to 3,000), more preferably 20 or more (e.g., 20 to 100), and most preferably 25 or more (e.g., 25 to 50). When the aspect ratio is equal to or higher than the lower limit, the mechanical properties tend to be improved, and when it is equal to or lower than the upper limit, the cellulose fibers tend to be more easily dispersed uniformly in the resin composition.

[0146] In this specification and claims, the average fiber diameter, average fiber length, and aspect ratio of cellulose fibers can be calculated by averaging 50 fibers randomly selected from a scanning electron microscope image. The average fiber diameter, average fiber length, and aspect ratio of cellulose fibers are those of the cellulose fibers in the resin composition (or molded product).

[0147] The proportion of the plant-derived filler (particularly cellulose fiber) relative to 100 parts by mass of the thermoplastic resin is, for example, 1 to 100 parts by mass, preferably 2 to 50 parts by mass, further preferably 3 to 30 parts by mass, even more preferably 5 to 20 parts by mass, and most preferably 10 to 15 parts by mass. If the proportion of the plant-derived filler is equal to or greater than the lower limit, the mechanical properties of the resin composition tend to improve, whereas if it is equal to or less than the upper limit, the dispersibility of the plant-derived filler in the resin composition tends to improve.

[0148] [Diacetal compounds] The resin composition of the present disclosure contains a diacetal compound represented by formula (1) (hereinafter referred to as "diacetal compound (1)"), which can improve the mechanical properties of the resin composition. Although the detailed mechanism by which the presence of a specific diacetal compound improves the mechanical properties of a resin composition is unknown, it is presumed that the specific diacetal compound has a specific structure and therefore exhibits a function similar to that of a compatibilizer between the plant-derived filler and the thermoplastic resin (particularly a polypropylene-based resin), thereby improving the dispersibility of the plant-derived filler and improving the mechanical properties.

[0149] In the formula (1), Z 1 and Z 2 Examples of the arene ring represented by the formula (I) include monocyclic arene rings such as a benzene ring, and polycyclic arene rings. Polycyclic arene rings include fused polycyclic arene rings (fused polycyclic hydrocarbon rings) and ring-assembled arene rings (ring-assembled aromatic hydrocarbon rings).

[0150] The fused polycyclic arene ring includes, for example, a fused bicyclic arene ring (e.g., a fused bicyclic C ring such as a naphthalene ring). 10-16 and fused bicyclic to tetracyclic arene rings such as fused tricyclic arene rings (e.g., anthracene ring, phenanthrene ring, etc.). Preferred fused polycyclic arene rings include a naphthalene ring and an anthracene ring, with a naphthalene ring being particularly preferred.

[0151] Examples of the ring-assembled arene ring include biarene rings [e.g., biphenyl rings, binaphthyl rings, phenylnaphthalene rings (e.g., 1-phenylnaphthalene rings, 2-phenylnaphthalene rings, etc.)] 6-12 arene rings, etc.], terarene rings (e.g., terphenylene rings, etc.) 6-12 Examples of preferred ring-assembly arene rings include biC 6-10 Examples include an arene ring, particularly a biphenyl ring.

[0152] Z 1 is Z 2 may be different from Z 2 It may be the same as Z 2 It is often the same ring as

[0153] Z 1 and Z 2 As the ring, a benzene ring, a naphthalene ring, or a biphenyl ring is preferred, and a benzene ring is particularly preferred.

[0154] R 1 and R 2 Examples of the alkyl group (linear or branched alkyl group) represented by the formula (I) include C groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, pentyl group, hexyl group, 2-ethylhexyl group, and octyl group. 1-12 Examples include alkyl groups.

[0155] R 1 is R 2 may be different from R 2may be the same as R 2 In many cases, the alkyl group is the same as that of the alkyl group.

[0156] R 1 and R 2 As the resin composition, C is preferred because it is easy to improve the mechanical properties of the resin composition. 1-6 Alkyl groups are preferred, and C 1-3 Alkyl groups are more preferred, and C 1-2 Alkyl groups are more preferred, and methyl groups are most preferred.

[0157] R 1 and R 2 The substitution numbers n and m are each an integer of 0 or more, and at least one of them may be an integer of 1 or more. However, from the viewpoint of facilitating improvement of the mechanical properties of the resin composition, it is preferable that both be integers of 1 or more, for example, an integer of 1 to 7, preferably an integer of 1 to 5, further preferably an integer of 1 to 3, more preferably 1 or 2, and most preferably 1.

[0158] R 3 and R 4 In the alkyl group having one or more hydroxyl groups represented by the formula (hereinafter referred to as "OH group-containing alkyl group"), the number of hydroxyl groups may be one or more and can be appropriately selected depending on the number of carbon atoms in the alkyl group. However, from the viewpoint of facilitating improvement in the mechanical properties of the resin composition, the number of hydroxyl groups is preferably two or more, more preferably 2 to 6, even more preferably 2 to 4, and most preferably 2 to 3.

[0159] The alkyl group in the OH group-containing alkyl group is the above-mentioned R 1 and R 2 Among the alkyl groups, C methyl group, ethyl group, propyl group, etc. 1-6 Alkyl groups are preferred, and linear C 1-4 Alkyl groups are more preferred, and linear C 2-4 Alkyl groups are more preferred, and linear C 2-3 Alkyl groups are most preferred.

[0160] Examples of the OH group-containing alkyl group include mono- to tetrahydroxy C groups such as hydroxymethyl group (methylol group), 2-hydroxyethyl group, 1,2-dihydroxyethyl group, 2,3-dihydroxypropyl group, 1,2,3-trihydroxypropyl group, 2,3,4-trihydroxybutyl group, and 1,2,3,4-tetrahydroxybutyl group. 1-6 Among these, di- or tetrahydroxy C groups such as 1,2-dihydroxyethyl groups are 2-4 Alkyl groups are preferred.

[0161] R 3 and R 4 At least one of the alkyl groups is preferably an OH group-containing alkyl group, and more preferably one of the alkyl groups is an OH group-containing alkyl group and the other is a hydrogen atom, and one of the alkyl groups is a linear C 1-6 Alkyl groups (especially linear C groups having two or more hydroxyl groups) 2-6 It is more preferable that one of the groups is an alkyl group and the other is a hydrogen atom.

[0162] Preferred diacetal compounds (1) include, for example, 1,3:2,4-bis-OC diacetal compounds such as 1,3:2,4-bis-O-(4-methylbenzylidene)-D-sorbitol and 1,3:2,4-bis-O-(4-ethylbenzylidene)-D-sorbitol. 1-3 Alkylbenzylidene-D-sorbitol; 1,3-OC such as 1,3-O-(4-methyl-benzylidene)-2,4-O-(3,4-dimethylbenzylidene)-D-sorbitol 1-3 Alkylbenzylidene-2,4-O-diC 1-3 Alkylbenzylidene-D-sorbitol; 1,3-O-(3,4-dimethyl-benzylidene)-2,4-O-(-methylbenzylidene)-D-sorbitol 1,3-O-diC 1-3 Alkylbenzylidene-2,4-OC 1-3Alkylbenzylidene-D-sorbitol; 1,3:2,4-bis-O-diC such as 1,3-O-(3,4-dimethyl-benzylidene)-2,4-O-(3,4-dimethylbenzylidene)-D-sorbitol and 1,3-O-(3,4-diethyl-benzylidene)-2,4-O-(3,4-diethylbenzylidene)-D-sorbitol 1-3 Alkyl benzylidene-D-sorbitol and the like.

[0163] These diacetal compounds (1) can be used alone or in combination.

[0164] The proportion of the diacetal compound (1) can be selected, for example, from a range of about 0.01 to 100 parts by mass relative to 100 parts by mass of the thermoplastic resin, preferably in the following stepwise manner: 0.1 to 80 parts by mass, 0.5 to 50 parts by mass, 1 to 30 parts by mass, 1.5 to 20 parts by mass, 2 to 10 parts by mass, 2.5 to 8 parts by mass, and most preferably 3 to 5 parts by mass. When the proportion of the diacetal compound (1) is equal to or greater than the lower limit, the plant-derived filler tends to be reinforced, improving the mechanical properties of the resin composition. When the proportion is equal to or less than the upper limit, deterioration of the mechanical properties of the resin composition due to an excess of the diacetal compound (1) tends to be suppressed.

[0165] The proportion of the diacetal compound (1) is 1 part by mass or more (particularly 20 parts by mass or more) per 100 parts by mass of the plant-derived filler, for example, 1 to 100 parts by mass, preferably 3 to 80 parts by mass, even more preferably 5 to 70 parts by mass, even more preferably 10 to 50 parts by mass, and most preferably 20 to 40 parts by mass.

[0166] [Other ingredients] In addition to the thermoplastic resin, plant-derived filler, and diacetal compound (1), the resin composition of the present disclosure may further contain conventional additives as other components. Examples of conventional additives include plasticizers, stabilizers (antioxidants, UV absorbers, light stabilizers, heat stabilizers, etc.), acid scavengers, conductive agents, antistatic agents, flame retardants (phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, etc.), flame retardant aids, impact modifiers, flow improvers, leveling agents, defoamers, non-plant-derived reinforcing materials (fibrous reinforcing materials such as glass fiber, carbon fiber, and synthetic fiber, fillers such as talc and calcium carbonate), colorants, lubricants, release agents, color modifiers, dispersants, antibacterial agents, preservatives, stress reducers, and nucleating agents. These additives can be used alone or in combination.

[0167] The total proportion of other components may be, for example, 100 parts by mass or less (e.g., 0.1 to 100 parts by mass) relative to 100 parts by mass of the thermoplastic resin, preferably 50 parts by mass or less (e.g., 1 to 50 parts by mass), even more preferably 30 parts by mass or less, even more preferably 10 parts by mass or less, and most preferably 5 parts by mass or less.

[0168] [Characteristics of resin composition and production method] The resin composition of the present disclosure has excellent mechanical properties. The flexural strength of the resin composition of the present disclosure can be appropriately selected depending on the type of thermoplastic resin, but may be, for example, 10 MPa or more, for example, 10 to 300 MPa, preferably 30 to 250 MPa, and more preferably 50 to 200 MPa.

[0169] When the thermoplastic resin is a polyolefin-based resin (particularly, a combination of a polypropylene-based resin and an acid-modified polyolefin-based resin), the flexural strength of the resin composition is, for example, 10 to 300 MPa, preferably 20 to 200 MPa, even more preferably 30 to 150 MPa, even more preferably 50 to 100 MPa, and most preferably 60 to 70 MPa.

[0170] When the thermoplastic resin is a polyester resin, the flexural strength of the resin composition is, for example, 10 to 300 MPa, preferably 20 to 250 MPa, further preferably 30 to 200 MPa, even more preferably 50 to 150 MPa, and most preferably 80 to 100 MPa.

[0171] When the thermoplastic resin is a polyamide resin, the flexural strength of the resin composition is, for example, 10 to 300 MPa, preferably 20 to 250 MPa, further preferably 30 to 230 MPa, even more preferably 50 to 200 MPa, and most preferably 100 to 150 MPa.

[0172] The flexural modulus of the resin composition of the present disclosure can be appropriately selected depending on the type of thermoplastic resin, but may be 2000 MPa or more, for example, 2000 to 7000 MPa, preferably 2500 to 6000 MPa, and more preferably 2800 to 5500 MPa.

[0173] When the thermoplastic resin is a polyolefin resin (particularly a combination of a polypropylene resin and an acid-modified polyolefin resin), the flexural modulus of the resin composition is, for example, 2000 to 5000 MPa, preferably 2500 to 4000 MPa, and more preferably 2800 to 3500 MPa.

[0174] When the thermoplastic resin is a polyester resin, the flexural modulus of the resin composition is, for example, 2000 to 5000 MPa, preferably 2500 to 4000 MPa, and more preferably 3000 to 3500 MPa.

[0175] When the thermoplastic resin is a polyamide resin, the flexural modulus of the resin composition is, for example, 2000 to 5000 MPa, preferably 2500 to 4000 MPa, and more preferably 3000 to 3500 MPa.

[0176] In this specification and claims, the flexural strength and flexural modulus of the resin composition can be measured in accordance with ISO 178.

[0177] The resin composition of the present disclosure can be produced by a conventional method depending on the type of thermoplastic resin. For example, it can be prepared by mixing a thermoplastic resin, a plant-derived filler, and a diacetal compound (1) by a conventional method such as dry mixing or melt kneading. The resin composition may be in the form of pellets or the like. When melt kneading, the kneading temperature can be appropriately selected depending on the type of thermoplastic resin, but is, for example, 150 to 300°C, preferably 200 to 280°C, more preferably 200 to 270°C, more preferably 210 to 260°C, and most preferably 230 to 250°C. A conventional method can be used for melt kneading, and for example, a twin-screw extrusion kneader may be used.

[0178] [Strength improver] The strength improver of the present disclosure is a strength improver for improving the strength of a resin composition containing a thermoplastic resin and a plant-derived filler, and includes a diacetal compound (1). The diacetal compound (1), including preferred embodiments, is the same as the diacetal compound (1) of the resin composition.

[0179] In the strength improver of the present disclosure, the proportion of the diacetal compound (1) in the strength improver may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass. When the proportion of the diacetal compound (1) is equal to or greater than the lower limit, the strength of the resin composition tends to be highly improved.

[0180] [Molded body] The molded article of the present disclosure can be produced by molding the resin composition using a conventional molding method.

[0181] Examples of conventional molding methods include compression molding, injection molding, injection compression molding, extrusion molding, transfer molding, blow molding, pressure molding, casting molding, etc. Among these molding methods, for example, injection molding, injection compression molding, and extrusion molding are preferred, with injection molding being particularly preferred.

[0182] In the injection molding method, the cylinder temperature is, for example, 150 to 300° C., preferably 180 to 280° C., and more preferably 180 to 260° C. If the cylinder temperature is equal to or higher than the lower limit, moldability tends to be improved, and if it is equal to or lower than the upper limit, the mechanical properties of the molded article tend to be improved.

[0183] When the thermoplastic resin is a polyolefin resin, the cylinder temperature is, for example, 150 to 250°C, preferably 180 to 230°C, and more preferably 190 to 210°C.

[0184] When the thermoplastic resin is a polyester resin, the cylinder temperature is, for example, 150 to 300°C, preferably 220 to 280°C, and more preferably 240 to 260°C.

[0185] When the thermoplastic resin is a polyamide resin, the cylinder temperature is, for example, 150 to 300°C, preferably 220 to 280°C, and more preferably 240 to 260°C.

[0186] The injection pressure is, for example, 10 to 100 MPa, preferably 20 to 80 MPa, and more preferably 40 to 60 MPa.

[0187] The mold temperature is, for example, 10 to 130° C., preferably 15 to 120° C., and more preferably 20 to 100° C. If the mold temperature is equal to or higher than the lower limit, the productivity of the molded article tends to improve, and if it is equal to or lower than the upper limit, the mechanical properties of the molded article tend to improve.

[0188] When the thermoplastic resin is a polyolefin resin, the mold temperature is, for example, 10 to 100°C, preferably 15 to 50°C, and more preferably 20 to 40°C.

[0189] When the thermoplastic resin is a polyester resin, the mold temperature is, for example, 30 to 120°C, preferably 50 to 90°C, and more preferably 60 to 80°C.

[0190] When the thermoplastic resin is a polyamide resin, the mold temperature is, for example, 30 to 130°C, preferably 60 to 100°C, and more preferably 70 to 90°C.

[0191] The shape of the molded article of the present disclosure is not particularly limited and can be selected depending on the application, and examples thereof include one-dimensional structures such as linear or thread-like structures, two-dimensional structures such as film-like, sheet-like, and plate-like structures, and three-dimensional structures such as block-like, rod-like, tubular, hollow, etc. In particular, the resin composition of the present disclosure allows molded articles to be produced with high productivity by injection molding, so that even three-dimensional structures can be produced with high productivity. [Example]

[0192] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples. The raw materials, instruments, and evaluation methods used in the examples are as follows.

[0193] [Raw materials] (Plant-derived filler) Cellulose fiber: A sheet of plant-derived pulp (chemically unmodified fiber, average fiber diameter 40 μm, average fiber length 1 mm or more, cellulose purity 80% or more) cut into chips of approximately 4 mm x 4 mm, bulk density 0.15 g / cm 3

[0194] (Diacetal compounds with methyl-substituted aromatic rings) Gelall MD: 1,3:2,4-bis-O-(4-methylbenzylidene)-D-sorbitol, "Gelall MD" manufactured by New Japan Chemical Co., Ltd. Gelall DXR: 1,3:2,4-bis-O-(3,4-dimethylbenzylidene)-D-sorbitol, "Gelall DXR" manufactured by New Japan Chemical Co., Ltd.

[0195] (Diacetal compounds with unsubstituted aromatic rings) Gelall D: 1,3:2,4-bis-O-benzylidene-D-sorbitol, "Gelall D" manufactured by New Japan Chemical Co., Ltd.

[0196] (Comparative material) Sorbitol: D-sorbitol (sugar alcohol), manufactured by Tokyo Chemical Industry Co., Ltd.

[0197] (thermoplastic resin) Polypropylene resin (PP): Prime Polypro J105G manufactured by Prime Polymer Co., Ltd. Block polypropylene 1 (BPP1): Prime Polypro J705UG manufactured by Prime Polymer Co., Ltd. Block polypropylene 2 (BPP2): Prime Polypro J-466HP manufactured by Prime Polymer Co., Ltd. Maleic anhydride modified polypropylene resin (PP-MAH): "Rikeaid MG-400P" manufactured by Riken Vitamin Co., Ltd. High-density polyethylene resin (HDPE): "Novatec HD HJ490" manufactured by Japan Polyethylene Co., Ltd. Polybutylene terephthalate resin (PBT): "NovaDuran 5010R5" manufactured by Mitsubishi Engineering Plastics Corporation Polyamide 6 resin (PA6): Unitika Nylon A1030BRL manufactured by Unitika Ltd.

[0198] [Equipment used] Twin-screw extruder: Thermo Fisher Scientific "Process 11" Injection molding machine: Thermo Fisher Scientific "HAAKE MiniJet Pro"

[0199] [Flexural strength and flexural modulus] The flexural strength and flexural modulus of the strip specimens were measured in accordance with ISO 178.

[0200] [Examples 1 to 11 and Comparative Examples 1 to 20] Using a twin-screw extruder, the raw materials were kneaded in the mass proportions shown in Tables 1 to 4 at a temperature of 200° C., a screw rotation speed of 200 rpm, and a discharge rate of approximately 500 g / h to prepare pelletized resin compositions.

[0201] The obtained resin composition was injection molded using an injection molding machine under conditions of a cylinder temperature of 200°C and a mold temperature of 30°C to obtain strip-shaped test pieces.

[0202] When PBT was used as the thermoplastic resin, the temperature of the twin-screw extruder was changed to 240°C, the cylinder temperature of the injection molding machine to 250°C, and the mold temperature to 70°C.When PA6 was used, the temperature of the twin-screw extruder was changed to 240°C, the cylinder temperature of the injection molding machine to 250°C, and the mold temperature to 80°C.

[0203] The bending strength and bending modulus of the obtained strip-shaped test pieces were measured, and the results are shown in Tables 1 to 4.

[0204] [Table 1]

[0205] [Table 2]

[0206] [Table 3]

[0207] [Table 4]

[0208] As is clear from Tables 1 and 2, Examples 1 to 6, which contained PP, PP-MAH, cellulose fiber, and a diacetal compound having a methyl-substituted aromatic ring, had improved flexural strength and flexural modulus compared to Comparative Example 1, which contained only PP, and Comparative Example 2, which contained only PP, PP-MAH, and cellulose fiber. On the other hand, Comparative Examples 3 to 5, which contained PP, PP-MAH, and a diacetal compound having an unsubstituted aromatic ring, had inferior flexural strength and flexural modulus compared to Examples 1 to 6. Comparing Examples 1 to 6, the flexural modulus and flexural strength increased with increasing addition of the diacetal compound having a methyl-substituted aromatic ring. Furthermore, Comparative Example 6, which contained PP, PP-MAH, and sorbitol, had inferior flexural strength and flexural modulus compared to Examples 3 and 6.

[0209] As is clear from Table 3, Examples 7 and 8, which contained BPP, PP-MAH, cellulose fiber, and a diacetal compound having a methyl-substituted aromatic ring, had improved flexural strength and flexural modulus compared to Comparative Examples 7 and 11, which contained only BPP, and Comparative Examples 8 and 12, which contained only BPP, PP-MAH, and cellulose fiber. On the other hand, Comparative Examples 9 and 13, which contained BPP, PP-MAH, cellulose fiber, and a diacetal compound having an unsubstituted aromatic ring, were inferior in flexural strength and flexural modulus compared to Examples 7 and 8. Furthermore, Comparative Examples 10 and 14, which contained BPP, PP-MAH, cellulose fiber, and sorbitol, were inferior in flexural strength and flexural modulus compared to Examples 7 and 8.

[0210] As is clear from Table 4, Examples 9, 10, and 11, which contained the corresponding resin, cellulose fiber, and diacetal compound having a methyl-substituted aromatic ring, had improved flexural strength and flexural modulus compared to Comparative Examples 15, 17, and 19, which contained only resin. Furthermore, Examples 9, 10, and 11, which contained the corresponding resin, cellulose fiber, and diacetal compound having a methyl-substituted aromatic ring, had improved flexural strength and flexural modulus compared to Comparative Examples 16, 18, and 20, which contained only resin and cellulose fiber. [Industrial Applicability]

[0211] The strength improver of the present disclosure has excellent dispersibility in thermoplastic resins and can be used as a strength improver for thermoplastic resins.

[0212] The resin composition of the present disclosure can be used for resin molded products in various fields [for example, automobile parts, electrical and electronic parts, building materials (wall materials, etc.), civil engineering materials, agricultural materials, packaging materials (containers, cushioning materials, etc.), living materials (daily commodities, etc.), optical components, etc.].

Claims

1. A resin composition comprising a thermoplastic resin, a plant-derived filler, and a diacetal compound represented by the following formula (1): 【Chemistry 1】 (In the formula, Z １ and Z ２ each independently represents an arene ring, R １ and R ２ independently represent an alkyl group, n and m independently represent an integer of 0 or more, and at least one of n and m represents an integer of 1 or more, R ３ and R ４ each independently represents an alkyl group having one or more hydroxyl groups or a hydrogen atom.

2. In the formula (1), R ３ and R ４ At least one of the C has one or more hydroxyl groups １－６ The resin composition of claim 1, wherein the alkyl group is present.

3. In the formula (1), R ３ and R ４ one of which is a linear C having two or more hydroxyl groups ２－６ 2. The resin composition according to claim 1, wherein one of the groups represents an alkyl group and the other represents a hydrogen atom.

4. In the formula (1), Z １ and Z ２ represents a benzene ring, and R １ and R ２ is C １－３ The resin composition according to any one of claims 1 to 3, wherein n and m represent an alkyl group, and each independently represents an integer of 1 or more.

5. The resin composition according to any one of claims 1 to 3, comprising 1 to 100 parts by mass of the plant-derived filler and 0.01 to 100 parts by mass of the diacetal compound relative to 100 parts by mass of the thermoplastic resin.

6. 4. The resin composition according to claim 1, wherein the ratio of the diacetal compound is 1.5 to 20 parts by mass per 100 parts by mass of the thermoplastic resin.

7. The resin composition according to any one of claims 1 to 3, wherein the ratio of the diacetal compound is 20 parts by mass or more per 100 parts by mass of the plant-derived filler.

8. The resin composition according to any one of claims 1 to 3, wherein the plant-derived filler comprises cellulose fiber.

9. The resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin comprises a polyolefin-based resin.

10. The resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin comprises a polypropylene-based resin and an acid-modified polyolefin-based resin.

11. The method for producing the resin composition according to any one of claims 1 to 3, comprising a step of kneading the thermoplastic resin, the plant-derived filler, and the diacetal compound represented by formula (1).

12. A molded article formed from the resin composition according to any one of claims 1 to 3, which is a part or material selected from the group consisting of automobile parts, electric / electronic parts, building materials, civil engineering materials, agricultural materials, packaging materials, daily living materials, and optical components.

13. A strength improver for improving the strength of a resin composition containing a thermoplastic resin and a plant-derived filler, the strength improver comprising a diacetal compound represented by the following formula (1): 【Chemistry 2】 (In the formula, Z １ and Z ２ each independently represents an arene ring, R １ and R ２ independently represent an alkyl group, n and m independently represent an integer of 0 or more, and at least one of n and m represents an integer of 1 or more, R ３ and R ４ each independently represents an alkyl group having one or more hydroxyl groups or a hydrogen atom.

14. A method for improving the mechanical properties of a resin composition comprising a thermoplastic resin and a plant-derived filler, by blending a diacetal compound represented by the following formula (1): 【Transformation 3】 (In the formula, Z １ and Z ２ each independently represents an arene ring, R １ and R ２ independently represent an alkyl group, n and m independently represent an integer of 0 or more, and at least one of n and m represents an integer of 1 or more, R ３ and R ４ each independently represents an alkyl group having one or more hydroxyl groups or a hydrogen atom.

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