Thermoplastic resin composition

Abstract

To provide a thermoplastic resin composition containing a styrenic resin composition, which suppresses lowering of tensile elastic modulus, and is excellent in tensile breaking elongation.SOLUTION: A thermoplastic resin composition contains a styrenic resin composition, wherein the styrenic resin composition contains (A) a styrenic polymer having a syndiotactic structure, and (B) dimethyl silicone oil, the content of (B) the dimethyl silicone oil is 0.1 to 10 pts.mass with respect to 100 pts.mass of the styrenic polymer having (A) the syndiotactic structure, a rubber-like elastic body is not substantially contained, and (A) the styrenic polymer having the syndiotactic structure is contained as the main component in the thermoplastic resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin composition, and more particularly to a thermoplastic resin composition containing a styrene-based resin composition. [Background technology]

[0002] Styrenic polymers with a syndiotactic structure have excellent heat resistance, chemical resistance, and electrical properties, and are therefore widely used in automotive parts, tableware, food containers, electrical and electronic components, etc.

[0003] For example, Patent Document 1 discloses an impact-resistant polystyrene resin composition comprising (A) 100 parts by weight of a styrene polymer having a syndiotactic structure and (B) 1 to 100 parts by weight of a rubber-like elastomer having a polar group, the composition being aimed at a syndiotactic polystyrene resin composition having excellent heat resistance, elastic modulus, impact resistance, and elongation. Furthermore, Patent Document 2 discloses an impact-resistant polystyrene resin composition that is excellent in heat resistance, elastic modulus, and moldability, as well as in impact resistance and elongation, and is obtained by blending 1 to 100 parts by weight of (C) a rubber-like elastomer with 100 parts by weight of a mixture of (A) 95.0 to 99.9% by weight of a styrene polymer having a syndiotactic structure and (B) 0.1 to 5.0% by weight of a polyphenylene ether. Furthermore, Patent Document 3 discloses a syndiotactic polystyrene resin composition for the purpose of providing a resin composition and molded articles thereof that have heat resistance and practical impact strength, excellent fluidity and retention stability, and reduced mold contamination during molding. The syndiotactic polystyrene resin composition contains, relative to a total of 100 parts by mass of (a) 22 to 99.5% by mass of a styrene polymer having a syndiotactic structure and (b) 0.5 to 78% by mass of a hydrogenated styrene-butadiene-styrene block copolymer, (c) 0.005 to 6 parts by mass of a crystal nucleating agent, (d) 0.005 to 6 parts by mass of an antioxidant that does not contain phosphorus in its structure, and (e) 3 to 155 parts by mass of a fibrous reinforcing agent, and further contains 0.005 to 6 parts by mass of (f) a silicone oil that has a methyl group and / or a phenyl group in its structure and has 100 ppm or less of an oligomer component of tetramer or less, relative to a total of 100 parts by mass of components (a) to (e). Furthermore, Patent Document 4 discloses a styrene-based resin composition that aims to provide a syndiotactic styrene-based resin composition that has high mold-release properties during molding and that does not bleed out into the mold or have little effect on the appearance of the product, and that contains (A) 100 to 5% by weight (inclusive) of a styrene-based polymer having a predominantly syndiotactic structure, (B) 0 to 95% by weight (inclusive) of a thermoplastic resin and / or rubber-like elastomer other than a styrene-based polymer having a predominantly syndiotactic structure, and (C) 0.01 to 0.5 parts by weight of dimethylsilicone oil having less than 10 ppm of oligomer components with 10 or less silicon atoms and a viscosity at 25°C of 90 to 50,000 cSt, per 100 parts by weight of the total of (A) and (B). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-256607 [Patent Document 2] Japanese Patent Application Publication No. 7-053815 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-21076 [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-265021 Summary of the Invention [Problem to be solved by the invention]

[0005] Although styrene polymers having a syndiotactic structure have various excellent physical properties, there is still room for further improvement in the toughness of molded articles, particularly the tensile elongation at break. Although the cited documents 1 and 2 describe that toughness can be improved by adding a rubber-like elastomer to a polystyrene-based resin composition, the inclusion of the rubber-like elastomer sometimes results in a decrease in the tensile modulus of the polystyrene-based resin composition. Furthermore, Patent Documents 3 and 4 describe that blending silicone oil into a styrene-based resin composition reduces mold contamination during molding and improves mold releasability, but on the other hand, sufficient performance such as rigidity and toughness may not be achieved, leaving room for further improvement. An object of the present invention is to provide a thermoplastic resin composition containing a styrene-based resin composition, which is inhibited from decreasing in tensile modulus and has excellent tensile elongation at break. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by a thermoplastic resin composition containing a styrene-based resin composition in which a styrene-based polymer having a syndiotactic structure is combined with (B) dimethyl silicone oil. That is, the present invention relates to the following [1] to [9].

[0007] [1] A thermoplastic resin composition comprising a styrene-based resin composition, the styrene-based resin composition comprising (A) a styrene-based polymer having a syndiotactic structure and (B) a dimethylsilicone oil, the content of the dimethylsilicone oil being 0.1 to 10 parts by mass per 100 parts by mass of the styrene-based polymer having a syndiotactic structure (A), the thermoplastic resin composition being substantially free of a rubber-like elastomer, and the thermoplastic resin composition comprising the styrene-based polymer having a syndiotactic structure (A) as a main component. [2] The thermoplastic resin composition according to [1], wherein the (B) dimethyl silicone oil is at least one selected from unmodified dimethyl silicone oil and modified dimethyl silicone oil. [3] The thermoplastic resin composition according to [1] or [2], wherein the viscosity of the (B) dimethyl silicone oil at 25°C is 1 to 1,200,000 cSt. [4] The thermoplastic resin composition according to any one of [1] to [3], wherein the styrene-based resin composition further comprises (C) a functional group-containing polyphenylene ether, the functional group of the (C) functional group-containing polyphenylene ether is a functional group derived from an acid and / or a derivative thereof, and the content of the (C) functional group-containing polyphenylene ether is 0.1 to 10 parts by mass per 100 parts by mass of the (A) styrene-based polymer having a syndiotactic structure. [5] The thermoplastic resin composition according to [4], wherein the functional groups of the functional group-containing polyphenylene ether (C) derived from an acid and / or a derivative thereof are at least one selected from maleic anhydride, maleic acid, fumaric acid, maleic acid esters, fumaric acid esters, maleate salts, fumarate salts, acrylic acid, acrylic acid esters, acrylic acid amides, acrylic acid salts, methacrylic acid, methacrylic acid esters, methacrylic acid amides, methacrylic acid salts, and glycidyl methacrylate. [6] The thermoplastic resin composition according to any one of [1] to [5], wherein the styrene-based resin composition further contains a nucleating agent, and the content of the nucleating agent is 0.1 to 3 parts by mass per 100 parts by mass of the styrene-based polymer (A) having a syndiotactic structure. [7] The thermoplastic resin composition according to any one of [1] to [6], wherein the styrene-based resin composition further contains a metal compound, and the content of the metal compound is 0.001 to 10 parts by mass per 100 parts by mass of the styrene-based polymer (A) having a syndiotactic structure. [8] The thermoplastic resin composition according to any one of [1] to [7], further comprising glass fibers. [9] The thermoplastic resin composition according to [8], wherein the content of the glass fiber is 5 to 50 mass % of the total of the styrene-based resin composition and the glass fiber. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a thermoplastic resin composition containing a styrene-based resin composition, which is inhibited from decreasing in tensile modulus and has excellent tensile elongation at break. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Thermoplastic resin composition] The thermoplastic resin composition of the present invention is a thermoplastic resin composition containing a styrene-based resin composition, wherein the styrene-based resin composition contains (A) a styrene-based polymer having a syndiotactic structure and (B) a dimethylsilicone oil, the content of the (B) dimethylsilicone oil is 0.1 to 10 parts by mass per 100 parts by mass of the (A) styrene-based polymer having a syndiotactic structure, the thermoplastic resin composition is substantially free of a rubber-like elastomer, and the (A) styrene-based polymer having a syndiotactic structure is contained as a main component in the thermoplastic resin composition.

[0010] <Styrene-based resin composition> The thermoplastic resin composition of the present invention includes a styrene-based resin composition, which includes (A) a styrene-based polymer having a syndiotactic structure and (B) a dimethylsilicone oil. The thermoplastic resin composition of the present invention is substantially free of a rubber-like elastomer.

[0011] ((A) Styrene-based polymer having a syndiotactic structure) (A) Styrenic polymer having a syndiotactic structure (hereinafter also referred to as (A)SPS) is a styrene-based resin having a highly syndiotactic structure. In this specification, "syndiotactic" means that the phenyl rings of adjacent styrene units are highly arranged alternately with respect to the plane formed by the main chain of the polymer block (hereinafter referred to as syndiotacticity). Tacticity is measured by nuclear magnetic resonance (NMR) using carbon isotopes. 13 Quantitative identification can be performed using the C-NMR method. 13 By C-NMR, the proportion of consecutive structural units, for example, two consecutive monomer units as a dyad, three consecutive monomer units as a triad, and five consecutive monomer units as a pentad, can be quantified.

[0012] In the present invention, the term "styrene resin having a highly syndiotactic structure" refers to a styrene polymer such as polystyrene, poly(hydrocarbon-substituted styrene), poly(halogenated styrene), poly(halogenated alkylstyrene), poly(alkoxystyrene), or poly(vinyl benzoate ester), having a syndiotacticity of typically 75 mol % or more, preferably 85 mol % or more in racemic diad (r), or typically 30 mol % or more, preferably 50 mol % or more in racemic pentad (rrrr), a hydrogenated polymer or mixture of these, or a copolymer having these as the main component.

[0013] Examples of poly(hydrocarbon-substituted styrenes) include poly(methylstyrene), poly(ethylstyrene), poly(isopropylstyrene), poly(tert-butylstyrene), poly(phenylstyrene), poly(vinylnaphthalene), and poly(vinylstyrene). Examples of poly(halogenated styrenes) include poly(chlorostyrene), poly(bromostyrene), and poly(fluorostyrene). Examples of poly(halogenated alkylstyrenes) include poly(chloromethylstyrene). Examples of poly(alkoxystyrenes) include poly(methoxystyrene) and poly(ethoxystyrene).

[0014] Examples of comonomer components of copolymers containing the structural units include, in addition to the monomers of the styrene polymers, olefin monomers such as ethylene, propylene, butene, hexene, and octene; diene monomers such as butadiene and isoprene; and polar vinyl monomers such as cyclic olefin monomers, cyclic diene monomers, methyl methacrylate, maleic anhydride, and acrylonitrile. Copolymers that can be suitably used as SPS include a copolymer of styrene and p-methylstyrene, a copolymer of styrene and p-tert-butylstyrene, and a copolymer of styrene and divinylbenzene, with a copolymer of styrene and p-methylstyrene being preferred.

[0015] Among the (A) SPS, at least one selected from polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene), and a copolymer of styrene and p-methylstyrene is preferred, at least one selected from polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), and a copolymer of styrene and p-methylstyrene is more preferred, polystyrene and a copolymer of styrene and p-methylstyrene are even more preferred, and polystyrene is most preferred.

[0016] The melt flow rate (MFR) of (A) SPS is preferably 3 to 50 g / 10 min, more preferably 5 to 40 g / 10 min, and even more preferably 8 to 35 g / 10 min, when measured at a temperature of 300°C and a load of 1.2 kg. If the MFR of (A) SPS is 3 g / 10 min or more, the thermoplastic resin composition will have excellent fluidity when used in molding or the like, and if it is 50 g / 10 min or less, the thermoplastic resin composition will have sufficient strength.

[0017] The weight-average molecular weight of (A) SPS is preferably 10,000 to 300,000, more preferably 50,000 to 290,000, even more preferably 100,000 to 280,000, and still more preferably 150,000 to 270,000. If the weight-average molecular weight of (A) SPS is 10,000 or more, the thermal and mechanical properties of a molded article made using the thermoplastic resin composition are ensured, and if the weight-average molecular weight of (A) SPS is 300,000 or less, the flowability of the thermoplastic resin composition when used in molding or the like is ensured. In this specification, unless otherwise specified, the weight average molecular weight is a value measured by gel permeation chromatography using a GPC apparatus (HLC-8321GPC / HT) manufactured by Tosoh Corporation and a GPC column (GMHHR-H(S)HTC / HT) manufactured by Tosoh Corporation at 145°C using 1,2,4-trichlorobenzene as an eluent, and converted using a calibration curve of standard polystyrene. The weight-average molecular weight of SPS can be adjusted by appropriately selecting the type and amount of each catalyst component and the polymerization temperature, or by introducing hydrogen.

[0018] The content of (A) SPS in 100 parts by mass of the styrene-based resin composition is preferably 75.0 to 99.8 parts by mass, more preferably 80 to 99.5 parts by mass, even more preferably 85 to 99 parts by mass, and still more preferably 90 to 98.5 parts by mass. When the content of (A) SPS is within the above range, the lightweight property and electrical properties that are characteristic of SPS are exhibited, and the tensile modulus and tensile elongation at break of the thermoplastic resin composition are further improved.

[0019] The thermoplastic resin composition of the present invention contains (A) SPS as a major component. Here, "containing (A) SPS as a major component" means that the thermoplastic resin component contains 50 mass% or more of SPS (A). That is, in the thermoplastic resin composition of the present invention, the content of SPS (A) in the thermoplastic resin composition is 50 mass% or more, preferably 50 mass% or more but less than 100 mass%, more preferably 55 to 99.5 mass%, even more preferably 60 to 99 mass%, and still more preferably 65 to 98 mass%.

[0020] (A)SPS can be produced, for example, by polymerizing a styrene-based monomer (a monomer corresponding to the above-mentioned styrene-based polymer) in an inert hydrocarbon solvent or in the absence of a solvent using a titanium compound and a condensation product (aluminoxane) of water and trialkylaluminum as catalysts (for example, JP 2009-068022 A).

[0021] ((B) Dimethyl silicone oil) In the thermoplastic resin composition of the present invention, the styrene-based resin composition contains (B) dimethyl silicone oil, and the content of (B) dimethyl silicone oil is 0.1 to 10 parts by mass per 100 parts by mass of (A) SPS.

[0022] The thermoplastic resin composition of the present invention, which contains (B) dimethyl silicone oil, suppresses the decrease in tensile modulus and exhibits excellent tensile elongation at break. The reason for this is not clear, but is considered to be as follows. (B) dimethyl silicone oil has moderate compatibility with (A) SPS. Therefore, it is believed that in the thermoplastic resin composition, (B) dimethyl silicone oil is uniformly dispersed in (A) SPS at sizes of several tens to several hundred nanometers. As a result, the thermoplastic resin composition has uniform properties, allowing for uniform deformation, which is thought to make it less susceptible to defects and breakage. Furthermore, because (B) dimethyl silicone oil is uniformly dispersed in large quantities within (A) SPS, the interparticle distance (the distance between particle surfaces) of (B) dimethyl silicone oil is small, which is thought to effectively prevent the progression of crazes that form before fracture. Furthermore, because (B) dimethyl silicone oil is dispersed in small amounts within (A) SPS, the surface area of ​​the (B) dimethyl silicone oil phase is large. This is thought to increase the interaction between (A) SPS and (B) dimethyl silicone oil, contributing to the slippage between (A) SPS crystals and affecting the mechanical properties of the thermoplastic resin composition. As a result, the tensile elongation at break of the thermoplastic resin is improved. Furthermore, since (B) dimethyl silicone oil is uniformly dispersed in (A) SPS in minute particles of several tens to several hundred nanometers in size, the tensile stress is uniformly dispersed in the thermoplastic resin composition, resulting in a tensile modulus close to that of (A) SPS, which is thought to suppress a decrease in the tensile modulus of the thermoplastic resin composition. From the above, it is believed that the thermoplastic resin of the present invention, which contains (B) dimethyl silicone oil, suppresses the decrease in tensile modulus and provides excellent tensile elongation at break.

[0023] In the thermoplastic resin composition of the present invention, the content of (B) dimethylsilicone oil is 0.1 to 10 parts by mass per 100 parts by mass of (A) SPS. When the content of (B) dimethylsilicone oil is 0.1 part by mass or more per 100 parts by mass of SPS, the (B) dimethylsilicone oil is sufficiently dispersed in (A) SPS in the thermoplastic resin composition, improving the tensile elongation at break of the thermoplastic resin. When the content of (B) dimethylsilicone oil is 10 parts by mass or less per 100 parts by mass of SPS, bleeding of the thermoplastic resin composition and deposits during molding are suppressed. From the same viewpoint as above, the content of (B) dimethyl silicone oil is preferably 0.2 to 7 parts by mass, more preferably 0.4 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of (A) SPS.

[0024] In the present invention, dimethyl silicone oil includes silicone oils based on a dimethyl silicone structure and modified products thereof (hereinafter also referred to as "modified dimethyl silicone oils"), but does not include methyl phenyl silicones and modified products thereof. Modified dimethyl silicones, regardless of whether they are reactive or non-reactive, include side chain type, both-end type, one-end type, and both-end type of side chain, depending on the position of the modified group introduced. Specific examples of modified dimethyl silicone oils include amino-modified dimethyl silicone oil, epoxy-modified dimethyl silicone oil, carboxy-modified dimethyl silicone oil, carbinol-modified dimethyl silicone oil, methacryl-modified dimethyl silicone oil, mercapto-modified dimethyl silicone oil, phenol-modified dimethyl silicone oil, polyether-modified dimethyl silicone oil, methylstyryl-modified dimethyl silicone oil, alkyl-modified dimethyl silicone oil, higher fatty acid ester-modified dimethyl silicone oil, and fluorine-modified dimethyl silicone oil. These dimethyl silicone oils may be used in combination.

[0025] In the present invention, from the viewpoint of suppressing a decrease in tensile modulus and improving tensile elongation at break, (B) dimethyl silicone oil is at least one selected from unmodified dimethyl silicone oil and modified dimethyl silicone oil, more preferably at least one selected from unmodified dimethyl silicone oil and amino-modified dimethyl silicone oil, and even more preferably unmodified dimethyl silicone oil.

[0026] The viscosity of (B) dimethyl silicone oil at 25°C is preferably 1 to 1,200,000 cSt, more preferably 5 to 100,000 cSt, even more preferably 10 to 50,000 cSt, even more preferably 20 to 25,000 cSt, even more preferably 30 to 15,000 cSt, even more preferably 50 to 1,000 cSt, and even more preferably 100 to 500 cSt. If the viscosity of the dimethyl silicone oil is less than 1 cSt, it will volatilize significantly due to heat during kneading with (A) SPS, resulting in less residual oil in the thermoplastic resin composition and insufficient property-improving effects. If the viscosity exceeds 1,200,000 cSt, the dispersibility of (A) SPS in the thermoplastic resin composition will decrease, making dispersion at tens to hundreds of nanometers difficult, resulting in insufficient property-improving effects. In the present invention, the viscosity of the silicone oil refers to the kinematic viscosity measured by a method in accordance with JIS K 2283.

[0027] (rubber-like elastic body) The thermoplastic resin composition of the present invention is substantially free of rubber-like elastomers. Generally, rubber-like elastic materials have flexibility and can impart flexibility to resin compositions, thereby improving the tensile elongation at break of the resin composition, but tend to decrease the tensile modulus. The thermoplastic resin composition of the present invention is substantially free of rubber-like elastomers, thereby making it possible to suppress a decrease in tensile modulus, and furthermore, by containing (B) dimethyl silicone oil, it is possible to suppress a decrease in tensile modulus and improve tensile elongation at break. Here, "substantially free of rubber-like elastomers" means that rubber-like elasticity is not intentionally added, and the content of rubber-like elastomers in the thermoplastic resin composition is 0.1% by mass or less, more preferably 0.01% by mass or less, even more preferably 0.001% by mass or less, and even more preferably 0% by mass.

[0028] Examples of the rubber-like elastic material in the present invention include natural rubber, polybutadiene, polyisoprene, polyisobutylene, neoprene, polysulfide rubber, thiokol rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, styrene-butadiene block copolymer (SBR), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), styrene-butadiene random copolymer, hydrogenated styrene-butadiene random copolymer, styrene-ethylene-propylene random copolymer, styrene-ethylene-butylene random copolymer, ethylene-propylene rubber (EPR), ethylene propylene diene rubber (EPDM), and modified rubbers thereof.

[0029] (Other ingredients) In the thermoplastic resin composition of the present invention, the styrene-based resin composition may contain any other components in addition to the above components, as long as the object of the present invention is not impaired. Other components may include, for example, (C) functional group-containing polyphenylene ether, a crystal nucleating agent, a metal oxide, an antioxidant, a flame retardant, a flame retardant assistant, a colorant, a crosslinking agent, a crosslinking assistant, a dispersant, a plasticizer, an antifouling agent, an ultraviolet absorber, a light stabilizer, and an antistatic agent.

[0030] <(C) Functional Group-Containing Polyphenylene Ether> In the thermoplastic resin composition of the present invention, the styrene-based resin composition preferably further contains (C) a functional group-containing polyphenylene ether, wherein the functional group is derived from an acid and / or a derivative thereof. When the thermoplastic resin composition contains (C) functional group-containing polyphenylene ether, the compatibility between (A) SPS and other components is further improved, and the interfacial strength between the components is further improved. As a result, the decrease in tensile modulus of the thermoplastic resin is further suppressed, and the tensile elongation at break is further improved. Furthermore, when the thermoplastic resin composition of the present invention contains glass fibers (described below), the functional groups derived from the acid and / or its derivatives in (C) functional group-containing polyphenylene ether react with the glass fibers, thereby further suppressing the decrease in tensile strength and further improving the tensile elongation at break.

[0031] The content of the (C) functional group-containing polyphenylene ether is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 7 parts by mass, even more preferably 0.4 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the (A) SPS. When the content of the (C) functional group-containing polyphenylene ether is 0.1 parts by mass or more, the compatibility between the (A) SPS and other components is improved. Furthermore, when the composition contains glass fibers (described below), the reactivity with the glass fibers is improved, resulting in a further improvement in the tensile elongation at break. Furthermore, when the content of the (C) functional group-containing polyphenylene ether is 10 parts by mass or less, the crystallinity of the (A) SPS is maintained, thereby further suppressing deterioration in the thermal and mechanical properties of the thermoplastic resin composition.

[0032] The functional groups of (C) functional group-containing polyphenylene ether are derived from acids and / or their derivatives. The compatibility of (A) SPS with other components is improved, resulting in improved interfacial strength between the components. This results in less deterioration in the tensile modulus of the thermoplastic resin and improved tensile elongation at break. The acid and / or a derivative thereof in the functional group derived from an acid and / or a derivative thereof is preferably at least one selected from maleic anhydride, maleic acid, fumaric acid, maleic acid esters, fumaric acid esters, maleates, fumarates, acrylic acid, acrylic acid esters, acrylic acid amides, acrylic acid salts, methacrylic acid, methacrylic acid esters, methacrylic acid amides, methacrylic acid salts, and glycidyl methacrylate, more preferably maleic anhydride, maleic acid, fumaric acid, and glycidyl methacrylate, and even more preferably fumaric acid. The functional group derived from an acid and / or a derivative thereof is preferably at least one selected from an acid anhydride group, a carboxylic acid group, a carboxylic acid ester group, a carboxylic acid halide group and a carboxylic acid amide group, and more preferably a carboxylic acid group.

[0033] The (C) functional group-containing polyphenylene ether is preferably at least one selected from fumaric acid-modified polyphenylene ether and maleic anhydride-modified polyphenylene ether, and more preferably fumaric acid-modified polyphenylene ether.

[0034] The modification rate (modifier content) of (C) functional group-containing polyphenylene ether is preferably 0.1 to 20.0 mass%, more preferably 0.2 to 15.0 mass%, even more preferably 0.3 to 10.0 mass%, and still more preferably 0.5 to 5.0 mass%, from the viewpoints of suppressing a decrease in tensile modulus and improving tensile elongation at break. The modification rate (modifier content) of the modified polyphenylene ether can be determined from the neutralization titer measured in accordance with JIS K 0070-1992.

[0035] (C) Functional group-containing polyphenylene ether can be obtained by reacting the polyphenylene ether described below with the acid and / or its derivative, thereby modifying the polyphenylene ether described below with the acid and / or its derivative. There are no particular limitations on the modification method, and known methods can be used. Preferred modification methods include melt modification and solution modification, and among these, melt modification is more preferred because a higher modification amount can be obtained and productivity is high. That is, the modified polyphenylene ether is preferably a modified polyphenylene ether produced by melt modification or a modified polyphenylene ether produced by solution modification, and more preferably a modified polyphenylene ether produced by melt modification.

[0036] Examples of polyphenylene ethers include poly(2,6-dimethyl-1,4-phenylene ether), poly(2,3-dimethyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-chloromethyl-1,4-phenylene ether), poly(2-methyl-6-hydroxyethyl-1,4-phenylene ether), poly(2-methyl-6-n-butyl-1,4-phenylene ether), poly(2-ethyl-6- isopropyl-1,4-phenylene ether), poly(2-ethyl-6-n-propyl-1,4-phenylene ether), poly(2,3,6-trimethyl-1,4-phenylene ether), poly[2-(4'-methylphenyl)-1,4-phenylene ether], poly(2-bromo-6-phenyl-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), poly(2-phenyl- 1,4-phenylene ether), poly(2-chloro-1,4-phenylene ether), poly(2-methyl-1,4-phenylene ether), poly(2-chloro-6-ethyl-1,4-phenylene ether), poly(2-chloro-6-bromo-1,4-phenylene ether), poly(2,6-di-n-propyl-1,4-phenylene ether), poly(2-methyl-6-isopropyl-1,4-phenylene ether), poly( At least one selected from poly(2-chloro-6-methyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2,6-dibromo-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), and poly(2,6-diethyl-1,4-phenylene ether) is preferred, and poly(2,6-dimethyl-1,4-phenylene ether) is more preferred.

[0037] Melt modification is a method of obtaining a modified polyphenylene ether by melt-kneading a polyphenylene ether and a modifier in the presence or absence of a radical generator. Specifically, this method involves melt-kneading and reacting the polyphenylene ether at a temperature in the range of 150 to 350°C using a roll mill, a Banbury mixer, an extruder, or the like. Specifically, a preferred method is to dry-blend polyphenylene ether, a modifier, and an optional radical generator uniformly at room temperature, and then carry out a melt reaction at a temperature substantially equal to the kneading temperature of polyphenylene ether, in the range of 300 to 350° C. If the temperature is 300° C. or higher, the melt viscosity can be appropriately maintained, and if the temperature is 350° C. or lower, decomposition of polyphenylene ether can be suppressed.

[0038] The amount of the modifier used in the melt modification is preferably 0.1 to 22.0 parts by mass, more preferably 0.2 to 17.0 parts by mass, even more preferably 0.3 to 12.0 parts by mass, and still more preferably 0.5 to 7.0 parts by mass, relative to 100 parts by mass of polyphenylene ether. When the amount of the modifier used is within the above range, the modification rate of the polyphenylene ether can be improved while the amount of the modifier remaining in the melt modified product can be reduced.

[0039] The radical generator used for melt modification is preferably one having a half-life of 1 minute at a temperature of 300°C or higher. Specific examples include 2,3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylhexane, and 2,3-dimethyl-2,3-di(p-methylphenyl)butane. Of these, 2,3-dimethyl-2,3-diphenylbutane, which has a half-life of 1 minute at a temperature of 330°C, is preferably used. The proportion of the radical generator used is preferably selected within the range of 0.1 to 3.0 parts by mass, more preferably 0.5 to 2.0 parts by mass, relative to 100 parts by mass of polyphenylene ether. If the amount is 0.1 part by mass or more, a high modification effect can be obtained, and if the amount is 3.0 parts by mass or less, the polyphenylene ether can be efficiently modified and insoluble components are less likely to be produced.

[0040] <Nucleating Agent> In the thermoplastic resin composition of the present invention, the styrene-based resin composition preferably further contains a crystal nucleating agent, which can increase the crystallization temperature, allowing a wider range of temperature conditions for crystallization to be set, and further improving productivity.

[0041] The nucleating agent is preferably at least one selected from the group consisting of inorganic nucleating agents and organic nucleating agents, with organic nucleating agents being particularly preferred. Examples of organic crystal nucleating agents include alkali metal salts of organic carboxylic acids, alkaline earth metal salts of organic carboxylic acids, organic compounds of phosphoric acid or phosphorous acid and metal salts thereof, phthalocyanine derivatives, and sorbitol derivatives. More specifically, for example, metal salts of carboxylic acids such as aluminum di(p-tert-butylbenzoate), sodium salt of benzoic acid, hydroxyaluminum salt of p-tert-butylbenzoic acid, aluminum hydroxy-di(p-tert-butylbenzoate), sodium methylenebis(2,4-di-tert-butylphenyl)phosphate, sodium-2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate, [2,2'-methylenebis(4,6-di-tert-butylphenyl)]phosphate, Metal salts of phosphoric acid such as lithium, [2,2'-methylenebis(4,6-di-tert-butylphenyl)]]phosphate, potassium bis(4-tert-butylphenyl)phosphate, sodium methylene(2,4-tert-butylphenyl)phosphate, aluminum bis(4,6',6,6'-tetra-tert-butyl-2,2'-methylenediphenyl phosphate) hydroxide, and ammonium [2,2'-methylenebis(4,6-di-tert-butylphenyl)]]phosphate can be selected and used. Complexes containing these can also be used. Among these, from the viewpoint of increasing the crystallization temperature, it is preferable to use a lithium salt of an organic compound of phosphoric acid or phosphorous acid, and it is more preferable to use lithium [2,2'-methylenebis(4,6-di-tert-butylphenyl)]]phosphate. Specific product names include ADK STAB NA-10, ADK STAB NA-11, ADK STAB NA-21, ADK STAB NA-30, ADK STAB NA-35, and ADK STAB NA-70 manufactured by ADEKA CORPORATION, and PTBBA-AL manufactured by Dainippon Ink and Chemicals, Inc.

[0042] In the thermoplastic resin composition of the present invention, the content of the crystal nucleating agent is preferably 0.1 to 3 parts by mass, more preferably 0.3 to 2 parts by mass, and even more preferably 0.5 to 1.5 parts by mass, relative to 100 parts by mass of (A) SPS. When the content of the crystal nucleating agent (C) is 0.1 parts by mass or more, a wider range of temperature conditions for crystallization can be set, further improving productivity. Furthermore, when the content is 3.0 parts by mass or less, the amount of gas components generated when the thermoplastic resin composition is used for molding or the like is suppressed, resulting in a better appearance.

[0043] ≪Metal compounds≫ In the thermoplastic resin composition of the present invention, the styrene-based resin composition preferably further contains a metal compound. When the styrene-based resin composition contains a metal compound, an ionic bond and / or a coordinate bond is formed between the functional group of the (C) functional group-containing polyphenylene ether and the metal ion of the metal compound, which is thought to result in ionomerization of the (C) functional group-containing polyphenylene ether. As a result, the decrease in the tensile modulus of the thermoplastic resin composition is further suppressed, and the tensile modulus is further improved, and the tensile elongation at break is also improved.

[0044] The metal compound is preferably at least one selected from metal salts, metal oxides, metal hydroxides and metal complexes, more preferably metal salts, from the viewpoint of suppressing a decrease in tensile modulus and improving tensile elongation at break. Examples of the metal species in the metal compound include alkali metals such as lithium, sodium, and potassium; alkaline earth metals such as magnesium, calcium, and barium; and aluminum. Examples include at least one metal selected from transition metals such as zinc, cobalt, chromium, and copper. Among these, from the viewpoints of suppressing a decrease in tensile modulus and improving tensile elongation at break, at least one metal selected from sodium, potassium, magnesium, calcium, and zinc is preferred, at least one metal selected from potassium, magnesium, and zinc is more preferred, and potassium is even more preferred.

[0045] The metal salt is preferably at least one selected from organic metal salts and inorganic metal salts. The organic metal salt is preferably at least one selected from formates, acetates and stearates of the above metal species, more preferably at least one selected from acetates and stearates, and even more preferably acetates. The inorganic metal salt is preferably at least one selected from carbonates, bicarbonates and halide salts of the above metal species.

[0046] Specifically, the metal compound is preferably at least one selected from potassium acetate, magnesium acetate, zinc acetate, potassium stearate, magnesium stearate, zinc stearate, potassium bicarbonate, potassium carbonate, and magnesium carbonate, and more preferably at least one selected from potassium acetate, zinc acetate, potassium stearate, magnesium stearate, potassium bicarbonate, and potassium carbonate.

[0047] In the thermoplastic resin composition of the present invention, the content of the metal compound is preferably 0.001 to 10 parts by mass, more preferably 0.003 to 5 parts by mass, even more preferably 0.005 to 2 parts by mass, and even more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the (A) SPS. When the content of the metal compound is 0.003 parts by mass or more, a large amount of the (C) functional group-containing polyphenylene ether is ionomerized, thereby further reducing the decrease in tensile modulus and further improving the tensile elongation at break. Furthermore, when the content of the metal compound is 5 parts by mass or less, excessive ionomerization of the (C) functional group-containing polyphenylene ether is prevented, thereby suppressing a decrease in melt fluidity and a decrease in moldability.

[0048] In the thermoplastic resin composition of the present invention, the mass ratio of the metal compound content to the (C) functional group-containing polyphenylene ether content [metal compound / (C) functional group-containing polyphenylene ether] is preferably 0.001 to 0.50, more preferably 0.003 to 0.10, even more preferably 0.005 to 0.05, and even more preferably 0.01 to 0.025. A mass ratio [metal compound / (C) functional group-containing polyphenylene ether] of 0.001 or more increases the amount of (C) functional group-containing polyphenylene ether that is ionomerized, thereby further reducing the decrease in tensile modulus and further improving tensile elongation at break. Furthermore, a mass ratio [metal compound / (C) functional group-containing polyphenylene ether] of 0.50 or less prevents excessive ionomerization of (C) functional group-containing polyphenylene ether, thereby suppressing a decrease in melt fluidity and a decrease in moldability.

[0049] <Antioxidants> In the thermoplastic resin composition of the present invention, the styrene-based resin composition preferably further contains an antioxidant from the viewpoint of durability. The antioxidant is preferably at least one selected from phenolic compounds, phosphorus-based compounds, and sulfur-based compounds, and from the viewpoint of heat resistance, a phenolic compound is more preferred.

[0050] Specific examples of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2,6-diphenyl-4-methoxyphenol, 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(4-methyl-6-nonylphenol), 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, and 2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane. ethylene glycol-bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate], 1,1-bis(3,5-dimethyl-2-hydroxyphenyl)-3-(n-dodecylthio)-butane, 4,4'-thiobis(6-tert-butyl-3-methylphenol), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonic acid dioctadecyl ester, n-octadecyl-3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, pentaerythritol tetrakis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate}, and the like. In particular, pentaerythritol tetrakis{3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate} is preferred.

[0051] Examples of phosphorus-based antioxidants include monophosphites and diphosphites such as 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tris(2,4-di-tert-butylphenyl)phosphite, and tris(mono- and di-nonylphenyl)phosphite.

[0052] Examples of sulfur-based antioxidants include 2,2-bis{[3-(dodecylthio)-1-oxopropoxy]methyl}propane-1,3-diylbis[3-(dodecylthio)propinate], di(tridecyl) 3,3'-thiodipropinate, and 3,3'-thiodipropinate.

[0053] In the thermoplastic resin composition of the present invention, the content of the antioxidant is preferably 0.05 to 2.0 parts by mass, more preferably 0.1 to 1.8 parts by mass, even more preferably 0.3 to 1.5 parts by mass, and even more preferably 0.5 to 1.2 parts by mass, relative to 100 parts by mass of (A) SPS. When the content of the antioxidant is within the above range, the durability of the thermoplastic resin is further improved, the heat discoloration resistance during processing is good, bleeding of the antioxidant is suppressed, and the appearance is not adversely affected.

[0054] <Glass fiber> The thermoplastic resin composition of the present invention preferably further contains glass fibers. By containing glass fibers, the strength of the thermoplastic resin composition can be improved and the decrease in tensile modulus can be further suppressed.

[0055] In the present invention, the glass fiber may be a glass fiber having a circular cross section or a glass fiber having a flat cross section. Among these, from the viewpoint of suppressing a decrease in the tensile modulus of the thermoplastic resin composition and ensuring flowability, a glass fiber having a circular cross section is preferred. In addition, a glass fiber having a circular cross section is preferred because it has no anisotropy derived from the cross-sectional direction of the glass fiber in a direction perpendicular to the direction of resin flow in the obtained molded product, and therefore has little variation in physical properties.

[0056] In this specification, glass fibers having a flat cross section refer to glass fibers whose cross section perpendicular to the fiber axis is flat. The flat shape refers to a shape in which the irregularity ratio of glass fibers having a flat cross section is greater than 1. In this specification, the irregularity ratio is the ratio of major axis to minor axis, where the length of the long side of this rectangle is the major axis and the length of the short side is the minor axis, assuming a rectangle with the smallest area circumscribing the cross section perpendicular to the longitudinal direction of the glass fiber. When glass fibers having a flat cross section are used, the deformation ratio of the glass fibers having a flat cross section is preferably 2.0 to 6.0, more preferably 3.0 to 5.0, and even more preferably 3.5 to 4.5, from the viewpoint of suppressing a decrease in the tensile modulus of the thermoplastic resin composition and ensuring flowability. The minor axis is preferably 3 to 10 μm, more preferably 5 to 8 μm.

[0057] The fiber diameter of the glass fiber is preferably 8 to 20 μm, more preferably 9 to 15 μm, and even more preferably 10 to 12 μm. When the fiber diameter of the glass fiber is 8 μm or more, the decrease in the tensile modulus of the thermoplastic resin composition is further suppressed, and when the fiber diameter is 20 μm or less, the flowability of the thermoplastic resin composition when used in molding or the like is ensured. In the present invention, the fiber diameter of a glass fiber means the diameter of a circle in a cross section perpendicular to the fiber axis in the case of a glass fiber having a circular cross section, and means the diameter of a circle having the same area as the area of ​​the cross section perpendicular to the fiber axis in the case of a glass fiber having a flat cross section.

[0058] The fiber length of the glass fiber is preferably 1 to 30 mm, more preferably 1.5 to 10 mm, and even more preferably 2 to 5 mm, from the viewpoint of ensuring the fluidity and handling of the thermoplastic resin composition when used in molding, etc. Furthermore, the fiber length of the glass fiber contained in the thermoplastic resin composition is preferably 200 to 600 μm due to breakage during extrusion kneading, etc.

[0059] In order to enhance adhesion to the (A) SPS, the glass fiber is preferably surface-treated with a coupling agent, more preferably with a silane-based coupling agent or a titanium-based coupling agent, and even more preferably with a silane-based coupling agent from the viewpoint of compatibility with the resin component.

[0060] Specific examples of silane coupling agents include triethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(1,1-epoxycyclohexyl)ethyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-mercaptopropyltrimethacrylate. Examples of suitable silanes include hydroxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltris(2-methoxyethoxy)silane, N-methyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-4,5-dihydroimidazolepropyltriethoxysilane, hexamethyldisilazane, N,N-bis(trimethylsilyl)urea, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine. Among these, preferred are aminosilanes and epoxysilanes such as γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0061] Specific examples of titanium-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(1,1-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, and bis(dioctyl pyrophosphate)oxyacetate. Titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tri(N-amidoethyl, aminoethyl) titanate, dicumyl phenyloxyacetate titanate, diisostearoyl ethylene titanate, etc. Among these, isopropyl tri(N-amidoethyl, aminoethyl) titanate is preferred.

[0062] When the thermoplastic resin composition of the present invention contains glass fibers, the content of the glass fibers in the thermoplastic resin composition is preferably 5 to 50 mass%, more preferably 10 to 45 mass%, and even more preferably 25 to 40 mass%, of the total of the styrene-based resin composition and the glass fibers. When the content of the glass fibers is 5 mass% or more, the decrease in the tensile modulus of the thermoplastic resin composition is further suppressed, and when the content is 50 mass% or less, the flowability of the thermoplastic resin composition when used in molding or the like is ensured.

[0063] [Production of Thermoplastic Resin Composition] The thermoplastic resin composition of the present invention is obtained by blending and kneading (A) SPS, (B) dimethyl silicone oil, and, if necessary, the other components described above. The blending and kneading can be carried out by premixing using commonly used equipment such as a ribbon blender, a drum tumbler, or a Henschel mixer, followed by using a Banbury mixer, a single-screw extruder, a twin-screw extruder, a multi-screw extruder, or a co-kneader. The melt-kneaded thermoplastic resin composition of the present invention is preferably stored in the form of pellets and used as a material for various molded articles and the like. [Example]

[0064] The present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples.

[0065] The raw materials used in the examples and comparative examples are as follows. <(A)SPS> Syndiotactic polystyrene resin, weight average molecular weight: 180,000, MFR (temperature 300°C, load 1.2 kgf): 13 g / 10 min, manufactured by Idemitsu Kosan Co., Ltd. <(B) Dimethyl silicone oil> ·SH200-350: “DOWSIL SH 200 Fluid 350cSt ", Dimethyl silicone oil, Viscosity at 25°C: 350cSt, Dow Toray Industries, Inc. SH200-13000: "DOWSIL SH 200 Fluid 13000cSt", dimethyl silicone oil, viscosity at 25°C: 13,000cSt, manufactured by Dow Toray Industries, Inc. KF96-100cs: Dimethyl silicone oil, viscosity at 25°C: 100cSt, manufactured by Shin-Etsu Chemical Co., Ltd. KF96-500cs: Dimethyl silicone oil, viscosity at 25°C: 500cSt, manufactured by Shin-Etsu Chemical Co., Ltd. KF-96H-1 million cs: Dimethyl silicone oil, viscosity at 25°C: 1,000,000 cSt, manufactured by Shin-Etsu Chemical Co., Ltd. KF-8008: Amino-modified dimethyl silicone oil with both ends; Viscosity at 25°C: 450 cSt, manufactured by Shin-Etsu Chemical Co., Ltd. <(B) Silicone oils other than dimethyl silicone oils> KF-53: Methylphenyl silicone oil, viscosity at 25°C: 175 cSt, manufactured by Shin-Etsu Chemical Co., Ltd. <(C) Functional Group-Containing Polyphenylene Ether> FAPPE-1 (produced by the method of Production Example 1): fumaric acid-modified polyphenylene ether, modification rate: 1.45% by mass <Nucleating agent> NA-70: "ADEKA STAB NA-70", [2,2'-methylenebis(4,6-di-tert-butylphenyl)]] lithium phosphate, manufactured by ADEKA Corporation <Metal compounds> Potassium acetate: (Fujifilm Wako Pure Chemical Industries, Ltd.) <Antioxidants> Irganox 1010: Pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], manufactured by BASF Japan Ltd. <Glass fiber> T-330H: "ECS03T-330H", average fiber diameter 10.5 μm, average fiber length 3 mm, manufactured by Nippon Electric Glass Co., Ltd. <Other> SEPTON8006: Hydrogenated styrene-butadiene-styrene block copolymer (rubber-like elastomer), styrene content 33%, manufactured by Kuraray Co., Ltd.

[0066] Production Example 1 (Production of FAPPE-1 (fumaric acid-modified polyphenylene ether)) 1 kg of polyphenylene ether (poly(2,6-dimethyl-1,4-phenylene ether)), intrinsic viscosity 0.45 dL / g in chloroform at 25°C), 30 g of fumaric acid, and 20 g of 2,3-dimethyl-2,3-diphenylbutane (NOFMER BC, NOFAM®) as a radical generator were dry-blended and melt-kneaded using a 30 mm twin-screw extruder at a screw speed of 200 rpm and a set temperature of 300°C. The resin temperature was approximately 331°C. The strands were water-cooled and pelletized to obtain FAPPE-1. To measure the modification rate, 1 g of the obtained FAPPE-1 was dissolved in ethylbenzene and reprecipitated in methanol. The recovered polymer was subjected to Soxhlet extraction with methanol, dried, and the modification rate was determined by the carbonyl absorption intensity in the IR spectrum and titration. The modification rate was found to be 1.45 wt%.

[0067] Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-2 (Production of Thermoplastic Resin Composition) The raw materials were blended in the proportions shown in Table 1 and melt-mixed using a kneader ("MC-15," manufactured by Xplore Instruments) at a mixing temperature of 300°C, a screw rotation speed of 50 rpm, and a mixing time of 3 minutes. The melt-mixed resin was then injected into a cylinder unit and molded into a thermoplastic resin composition using an Xplore 12cc injection molding machine (manufactured by Xplore Instruments) to obtain test specimens for thermoplastic resin composition measurements. Molding was performed at a cylinder temperature of 300°C and a mold temperature of 150°C. Dumbbell test specimens Type A12, which are half-scale dumbbell test specimens Type A1, were prepared in accordance with ISO 527-1,2:2012. Comparative Example 1-1 is a comparative example that does not contain (B) dimethyl silicone oil, and Comparative Example 1-2 is a comparative example that uses methylphenyl silicone oil instead of (B) dimethyl silicone oil.

[0068] (evaluation) <Tensile modulus and tensile elongation at break> Using the test specimens, the tensile modulus and tensile elongation at break were measured in accordance with ISO 527-1,2:2012 at a tensile speed of 1 mm / min and a measurement temperature of 23° C. The measurement results are shown in Table 1.

[0069] [Table 1]

[0070] Examples 2-1 to 2-8, Comparative Examples 2-1 to 2-3 (Production of Thermoplastic Resin Composition) The raw materials except for the glass fiber were mixed in the proportions shown in Table 2 and dry-blended in a Henschel mixer. The dry-blended raw materials were fed into a twin-screw extruder ("TEM37SS", manufactured by Shibaura Machine Co., Ltd.) and melt-kneaded at a screw rotation speed of 250 rpm and a cylinder temperature of 290°C while side-feeding the glass fiber so that the glass fiber content was in the proportion shown in Table 2. The resulting strand was water-cooled and pelletized to obtain pellets of the thermoplastic resin composition. The resulting thermoplastic resin composition pellets were dried in a hot air dryer at 120°C for 5 hours and used for evaluation. Comparative Example 2-1 is a comparative example that does not contain (B) dimethyl silicone oil, and Comparative Examples 2-2 and 2-3 are comparative examples in which a rubber-like elastic material is blended in place of (B) dimethyl silicone oil.

[0071] (evaluation) <Tensile modulus, tensile strength and tensile elongation at break> The obtained pellets of the thermoplastic resin composition were molded into dumbbell-shaped tensile test specimens (Type A) in accordance with JIS K 7139:2015 using an injection molding machine [SE100EV manufactured by Sumitomo Heavy Industries, Ltd.] at a cylinder temperature of 290°C and a mold temperature of 150°C. Using the test specimens, the tensile modulus, tensile strength, and tensile elongation at break were measured in accordance with ISO 527-1,2:2012 at a tensile speed of 5 mm / min and a measurement temperature of 23° C. The measurement results are shown in Table 2.

[0072] [Table 2]

[0073] Examples 3-1 to 3-3 (Production of Thermoplastic Resin Composition) The raw materials other than the metal oxide and the glass fiber were blended in the proportions shown in Table 3 and dry-blended in a Henschel mixer. The metal compound and the glass fiber shown in Table 3 were mixed so that the blending amount of the metal compound in the styrene-based resin composition was the proportion shown in Table 3, to obtain a mixture of the metal compound and the glass fiber. The dry-blended raw materials were fed into a twin-screw extruder ("TEM37SS", manufactured by Shibaura Machine Co., Ltd.), and melt-kneaded at a screw rotation speed of 250 rpm and a cylinder temperature of 290°C while side-feeding a mixture of metal compound and glass fiber so that the glass fiber content was in the proportion shown in Table 3. The resulting strand was water-cooled and pelletized to obtain pellets of a thermoplastic resin composition. The resulting thermoplastic resin composition pellets were dried in a hot air dryer at 120°C for 5 hours and used for evaluation.

[0074] (evaluation) <Preparation of test specimens> The obtained pellets of the thermoplastic resin composition were molded into dumbbell-shaped tensile test specimens (Type A) in accordance with JIS K 7139:2015 using an injection molding machine [SE100EV manufactured by Sumitomo Heavy Industries, Ltd.] at a cylinder temperature of 290°C and a mold temperature of 150°C. <Tensile modulus, tensile strength and tensile elongation at break> Using the test specimens, the tensile modulus, tensile strength, and tensile elongation at break were measured in accordance with ISO 527-1,2:2012 at a tensile speed of 5 mm / min and a measurement temperature of 23° C. The measurement results are shown in Table 3. <Flexural modulus and flexural strength> Using the test pieces, the flexural modulus and flexural strength were measured in accordance with ISO 178:2010 at a bending speed of 2 mm / min and a measurement temperature of 23° C. The measurement results are shown in Table 3.

[0075] [Table 3]

[0076] The results in Tables 1 to 3 show that the thermoplastic resin composition of the present invention is inhibited from decreasing in tensile modulus and is excellent in tensile elongation at break.

Claims

1. A thermoplastic resin composition comprising a styrene-based resin composition, The styrene-based resin composition (A) a styrene-based polymer having a syndiotactic structure, and (B) Dimethyl silicone oil Including, the content of the (B) dimethyl silicone oil is 0.1 to 10 parts by mass relative to 100 parts by mass of the (A) styrene-based polymer having a syndiotactic structure, Substantially does not contain rubber-like elastomers, A thermoplastic resin composition comprising the (A) styrene polymer having a syndiotactic structure as a main component.

2. 2. The thermoplastic resin composition according to claim 1, wherein the (B) dimethyl silicone oil is at least one selected from unmodified dimethyl silicone oil and modified dimethyl silicone oil.

3. 3. The thermoplastic resin composition according to claim 1, wherein the viscosity of the (B) dimethyl silicone oil at 25°C is 1 to 1,200,000 cSt.

4. the styrene-based resin composition further contains (C) a functional group-containing polyphenylene ether, the functional group of the functional group-containing polyphenylene ether (C) is a functional group derived from an acid and / or a derivative thereof, 3. The thermoplastic resin composition according to claim 1, wherein the content of the functional group-containing polyphenylene ether (C) is 0.1 to 10 parts by mass per 100 parts by mass of the styrene-based polymer having a syndiotactic structure (A).

5. 5. The thermoplastic resin composition according to claim 4, wherein, in the functional groups of the functional group-containing polyphenylene ether (C), the functional groups derived from an acid and / or a derivative thereof, the acid and / or the derivative thereof is at least one selected from maleic anhydride, maleic acid, fumaric acid, maleic acid esters, fumaric acid esters, maleate salts, fumarate salts, acrylic acid, acrylic acid esters, acrylic acid amides, acrylic acid salts, methacrylic acid, methacrylic acid esters, methacrylic acid amides, methacrylic acid salts, and glycidyl methacrylate.

6. the styrene-based resin composition further contains a crystal nucleating agent, The thermoplastic resin composition according to claim 1 or 2, wherein the content of the crystal nucleating agent is 0.1 to 3 parts by mass per 100 parts by mass of the styrene-based polymer (A) having a syndiotactic structure.

7. the styrene-based resin composition further contains a metal compound, 3. The thermoplastic resin composition according to claim 1, wherein the content of the metal compound is 0.001 to 10 parts by mass per 100 parts by mass of the styrene-based polymer (A) having a syndiotactic structure.

8. The thermoplastic resin composition according to claim 1 or 2, further comprising glass fibers.

9. The thermoplastic resin composition according to claim 8, wherein the content of the glass fiber is 5 to 50 mass% in the total of the styrene-based resin composition and the glass fiber.

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