Method for producing thermoplastic resin composition, method for determining moldability of thermoplastic resin composition, and thermoplastic resin composition for molding at temperature that is not less than decomposition temperature of elastomer

Abstract

One purpose of the present invention is to provide: a thermoplastic resin composition to which an elastomer is added, and which is capable of remarkably reducing the formation of mold adhering matters during molding especially in gas vents and clogging of the gas vents during injection molding of the thermoplastic resin composition at a temperature that is not less than the decomposition temperature of the elastomer, thereby being capable of suppressing the occurrence of gas scorching of an injection molded body; and a method for producing a thermoplastic resin composition. Another purpose of the present invention is to provide a method for determining whether or not operations of injection molding can be stably performed when a thermoplastic resin composition is injection molded at a temperature that is not less than the decomposition temperature of an elastomer.　The present invention provides a method for producing a thermoplastic resin composition which contains at least one thermoplastic resin that is selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins and syndiotactic polystyrene resins, an elastomer and an antioxidant, the method comprising a step in which the thermoplastic resin, the elastomer and the antioxidant are mixed with each other such that the formulae (mathematical formulae 1) are satisfied if a0 is the amount of gases having a boiling point of less than (T0 + 20)°C among the gases having a boiling point of 0°C to 400°C, the gases being generated during injection molding of the thermoplastic resin composition at a mold temperature T0°C that is not less than 40°C at the injection rate of 10 cm3 / second, b0 is the amount of gases having a boiling point of not less than (T0 - 20)°C among the gases having a boiling point of 0°C to 400°C, the gases being generated during the injection molding, and b10 is the amount of gases having a boiling point of not less than (T10 - 20)°C among the gases having a boiling point of 0°C to 400°C, the gases being generated during injection molding of the thermoplastic resin composition wherein the thermoplastic resin composition is injected into a mold at a mold temperature T10°C that is not less than 40°C at the injection rate of 10 cm3 / second, retained therein for 10 minutes, and subsequently molded (meanwhile, the unit of a0, b0 and b10 is µg per 1 g of the thermoplastic resin composition, and T0 = T10).

Description

Method for producing a thermoplastic resin composition, method for determining the moldability of a thermoplastic resin composition, and thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of an elastomer

[0001] The present invention relates to a method for producing a thermoplastic resin composition, a method for determining the moldability of a thermoplastic resin composition, and a thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of an elastomer, and more particularly to a method for producing a polyarylene sulfide resin composition, a method for determining the moldability of a polyarylene sulfide resin composition, and a polyarylene sulfide resin composition for molding at a temperature equal to or higher than the decomposition temperature of an elastomer.

[0002] Polyarylene sulfide (hereinafter also referred to as "PAS") resins, typified by polyphenylene sulfide (hereinafter also referred to as "PPS") resins, have high heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. For this reason, PAS resins are widely used as materials for electrical and electronic equipment components, automotive equipment components, chemical equipment components, and the like. PAS resins are particularly used as materials for parts used in high environmental temperatures.

[0003] Furthermore, various compositions containing PAS resins have been proposed. Specifically, known compositions include a composition containing a PAS resin and an olefin-based copolymer mainly composed of an α-olefin and a glycidyl ester of an α,β-unsaturated acid (e.g., Patent Document 1), and a composition containing a PAS resin and an olefin-based copolymer of ethylene and an α-olefin having 5 or more carbon atoms (e.g., Patent Document 2).

[0004] The resin compositions described in Patent Documents 1 and 2 have excellent high- and low-temperature impact properties. However, thermoplastic elastomers such as the above-mentioned olefin copolymers are prone to thermal degradation at high temperatures. Therefore, when injection molding is performed using the resin compositions described in Patent Documents 1 and 2 that contain thermoplastic elastomers, a new problem arises in that a large amount of mold deposits (hereinafter sometimes referred to as "mold deposits" or "MD") is likely to occur during molding.

[0005] Injection molding is widely used as an inexpensive and highly productive manufacturing method for thermoplastic resins. In injection molding of thermoplastic resins, granular resin, known as pellets, is first loaded into a cylinder by rotating a screw to measure the amount of resin. The pellets are then melted using a heater attached to the cylinder. The molten resin is then extruded by the screw and injected into the mold cavity (the entire space inside the mold where the resin is filled) at high speed. The resulting injection-molded product is then cooled. To prevent resin degradation, injection molding typically involves a processing temperature between the melting point (or flow temperature) and the thermal decomposition temperature of the base resin of the resin composition. However, various factors can cause the resin and additives in a thermoplastic resin composition to decompose in the molding machine. Decomposition of the resin and additives not only leads to deterioration of the resin itself, resulting in a decrease in physical properties. Decomposition gases and air entrained in the resin composition during metering are not properly expelled from the mold during injection, resulting in compression in the enclosed space, which can cause high temperatures and burn the resin composition. Furthermore, various substances, including decomposition gases produced by decomposition, adhere to gas vents, cavities, etc., causing MD. As described above, such problems can be made less likely by setting the processing temperature of injection molding within a specific range (for example, a temperature not exceeding the decomposition temperature of the resin or additives in the thermoplastic resin composition). However, depending on various circumstances (for example, when attempting to reduce the viscosity of the thermoplastic resin composition by plasticizing at a high temperature to ensure the fluidity of the thermoplastic resin composition during molding, or when the decomposition temperature of an additive contained in the molded article to impart specific performance to the molded article is lower than the processing temperature of the base thermoplastic resin), injection molding may be required at a temperature exceeding the decomposition temperature of these components.

[0006] As a method for solving the problem of MD formation in gas vents and cavities, a method has been proposed in which a PAS resin and a specific olefin copolymer (elastomer component) are blended with a specific antioxidant (see Patent Document 3). Patent Document 3 discloses that even when a PAS resin composition containing an elastomer component is injection molded at a high mold temperature of 130°C to 180°C, MD formation in gas vents and cavities during molding can be reduced.

[0007] JP 2000-263586 A JP 2002-179914 A WO2017 / 10364 A

[0008] However, prior art techniques such as those described in Patent Documents 1, 2, and 3 may not be able to fully resolve the problems of MD formation in gas vents and cavities and gas burning when molding a thermoplastic resin composition at or above the decomposition temperature of the components of the thermoplastic resin composition. That is, in the injection molding of PAS resin compositions disclosed in Patent Documents 1, 2, and 3, it is difficult to prevent the generation of decomposition gas originating from the elastomer blended in the resin composition. Therefore, if the generation of decomposition gas during molding cannot be avoided, MD will eventually form. Furthermore, as a result, gas burning may occur in molded articles obtained from the thermoplastic resin composition due to narrowing or clogging of the gas vent. For this reason, it must be said that injection molding of PAS resin compositions blended with elastomers still poses challenges.

[0009] The present inventors collected gases generated during injection molding of a thermoplastic resin composition and analyzed the type and amount of the collected gases. They found that gases having a boiling point below 20°C higher than the mold temperature T°C during injection molding (hereinafter referred to as "low-boiling gases") and gases having a boiling point at or above 20°C lower than T°C (hereinafter referred to as "high-boiling gases") were collected. Generally, high-boiling gases are the gases that cause MD formation (the mechanism will be described in detail later). Therefore, the inventors investigated the type and amount of additives that are effective in preventing the generation of high-boiling gases. However, as described above, when injection molding a resin composition in which it is difficult to avoid the generation of decomposition gases during molding, such as a PAS resin composition containing an elastomer, the generation of high-boiling gases cannot be avoided.

[0010] The present invention has been made to solve the above-mentioned problems, and its object is to provide a thermoplastic resin composition that can significantly reduce the formation of mold deposits and clogging of gas vents, particularly in gas vents, during injection molding of a thermoplastic resin composition containing an elastomer at a temperature equal to or higher than the decomposition temperature of the elastomer, thereby reducing the occurrence of gas burns in injection-molded articles. Another object of the present invention is to provide a method for producing such a thermoplastic resin composition. Yet another object of the present invention is to provide a method for determining whether injection molding can be performed stably when injection-molding a thermoplastic resin composition at a temperature equal to or higher than the decomposition temperature of the elastomer.

[0011] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, they have discovered that the formation of MD in gas vents can be prevented by adjusting the type of gas generated during injection molding of a thermoplastic resin composition containing an elastomer and an antioxidant, and have completed the present invention. More specifically, the present invention provides the following.

[0012] (1) A method for producing a thermoplastic resin composition containing one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant, the method comprising the steps of: (a) heating the thermoplastic resin composition at a mold temperature T of 40° C. or higher; ０ The thermoplastic resin composition was injected at an injection rate of 10 cm ３ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at 1 / sec, (T ０ +20) ° C. ０ Among the gases with a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ The amount of gas with a boiling point of -20°C or higher is b ０ and the thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. Mold temperature T １０ The gases with boiling points of 0 to 400°C are generated when the mixture is injected into a mold at 0°C, retained for 10 minutes, and then injection molded. １０ The amount of gas with a boiling point of -20°C or higher is b １０ ; (where a ０ , b ０ and b １０ The unit is μg / g of thermoplastic resin composition, and T ０ =T １０ ) and then, the following equations are obtained: [Equation 1] and mixing the thermoplastic resin, the elastomer, and the antioxidant so that all of the above requirements are satisfied.

[0013] (2) The method for producing a thermoplastic resin composition according to (1), wherein the antioxidant comprises one selected from the group consisting of a phenol-based antioxidant, a thioether-based antioxidant, a phosphorus-based antioxidant, and an amine-based antioxidant, and the content of the elastomer is 3.5 parts by weight or more per 100 parts by mass of the thermoplastic resin.

[0014] (3) The method for producing a thermoplastic resin composition according to (1) or (2), wherein the antioxidant is selected from phenolic antioxidants or thioether antioxidants, and the phenolic antioxidant has a tert-butyl group bonded to at least one of two carbon atoms in the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0015] (4) The method for producing a thermoplastic resin composition according to (3), wherein the phenolic antioxidant has a tert-butyl group bonded to one of two carbon atoms at the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0016] (5) A method for determining the moldability of a thermoplastic resin composition containing one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant, the method comprising the steps of: ０ The thermoplastic resin composition was injected at an injection rate of 10 cm ３ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at 1 / sec, (T ０ +20) ° C. ０ Among the gases having a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ The amount of gas with a boiling point of -20°C or higher is b ０ and the thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. Mold temperature T １０ The gases with boiling points of 0 to 400°C are generated when the injection molding is performed after the injection molding step. １０ The amount of gas with a boiling point of -20°C or higher is b １０ ; (where a ０ , b ０ and b １０ The unit is μg / g of thermoplastic resin composition, and T ０ =T １０ ) and then, the following equations are obtained: [Equation 2] and determining that the thermoplastic resin composition has good moldability when both of the above conditions are satisfied.

[0017] (6) The method for determining the moldability of a thermoplastic resin composition according to (5), wherein the antioxidant comprises one selected from the group consisting of a phenol-based antioxidant, a thioether-based antioxidant, a phosphorus-based antioxidant, and an amine-based antioxidant, and the content of the elastomer is 3.5 parts by weight or more per 100 parts by mass of the thermoplastic resin.

[0018] (7) The method for determining the moldability of a thermoplastic resin composition according to (5) or (6), wherein the antioxidant is selected from phenolic antioxidants or thioether antioxidants, and the phenolic antioxidant has a tert-butyl group bonded to at least one of two carbon atoms in the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0019] (8) The method for determining the moldability of a thermoplastic resin composition according to (7), wherein the phenolic antioxidant has a tert-butyl group bonded to one of two carbon atoms at the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0020] (9) A thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of the elastomer, comprising one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant, wherein the thermoplastic resin composition is molded at a mold temperature T of 40° C. or higher. ０ The thermoplastic resin composition was injected at an injection rate of 10 cm ３ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at 1 / sec, (T ０ +20) ° C. ０ Among the gases having a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ The amount of gas with a boiling point of -20°C or higher is b ０ and the thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. Mold temperature T １０The gases with boiling points of 0 to 400°C are generated when the injection molding is performed after the injection molding step. １０ The amount of gas with a boiling point of -20°C or higher is b １０ ; (where a ０ , b ０ and b １０ The unit is μg / g of thermoplastic resin composition, and T ０ =T １０ ) and then, the following equations are obtained: [Equation 3] and a thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of the elastomer, which satisfies both of the above requirements.

[0021] (10) The thermoplastic resin composition according to (9), wherein the antioxidant comprises one selected from the group consisting of phenol-based antioxidants, thioether-based antioxidants, phosphorus-based antioxidants, and amine-based antioxidants, and the content of the elastomer is 3.5 parts by weight or more per 100 parts by mass of the thermoplastic resin.

[0022] (11) The thermoplastic resin composition according to (9) or (10), wherein the antioxidant is selected from phenolic antioxidants or thioether antioxidants, and the phenolic antioxidant has a tert-butyl group bonded to at least one of two carbon atoms in the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0023] (12) The thermoplastic resin composition according to (11), wherein the phenolic antioxidant has a tert-butyl group bonded to one of two carbon atoms at the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0024] According to the present invention, a method for producing a thermoplastic resin composition can be provided that can significantly reduce the formation of MD, particularly in gas vents, during injection molding and prevent gas burning in the injection-molded article. It is also possible to provide a method for determining whether a thermoplastic resin composition can be successfully molded. Furthermore, it is possible to provide a thermoplastic resin composition that can significantly reduce the formation of MD in gas vents and prevent gas burning in the injection-molded article when injection molding is performed at a temperature equal to or higher than the decomposition temperature of the components in the thermoplastic resin composition.

[0025] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0026] First, a thermoplastic resin composition produced by a production method according to one embodiment will be described. The thermoplastic resin composition according to one embodiment contains one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant.

[0027] Polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, which are used as thermoplastic resins, are all known to have high heat resistance exceeding 200°C. Among these, polyarylene sulfide resins (PAS resins) are resins whose main constituent is the repeating unit -(Ar-S)- (where "Ar" represents an arylene group), and have a linear structure in which arylene groups and sulfur atoms are alternately bonded. Examples of the arylene group contained in PAS resins include p-phenylene, m-phenylene, o-phenylene, substituted phenylene, p,p'-diphenylsulfone, p,p'-biphenylene, p,p'-diphenylene ether, p,p'-diphenylenecarbonyl, and naphthalene groups, and the repeating units may contain two or more different arylene groups. The polyarylene sulfide resin used in the embodiment is preferably a polyphenylene sulfide (PPS) resin using a p-phenylene group as the arylene group. Homopolymers having p-phenylene sulfide groups as repeating units are known to have high heat resistance and exhibit high strength, high rigidity, and high dimensional stability over a wide temperature range.

[0028] As a PAS resin containing two or more different arylene groups as repeating units, a resin containing a combination of p-phenylene sulfide groups and m-phenylene sulfide groups is preferably used from the viewpoint of physical properties such as heat resistance, moldability, and mechanical properties. Among the above-mentioned resins, polymers containing p-phenylene sulfide groups at a ratio of 70 mol % or more are more preferred, and polymers containing p-phenylene sulfide groups at a ratio of 80 mol % or more are even more preferred. Furthermore, among these PAS resins, high-molecular-weight polymers with a substantially linear structure that can be obtained by condensation polymerization from monomers primarily composed of bifunctional halogenated aromatic compounds are particularly preferred. These PAS resins can be used alone or in combination of two or more.

[0029] Examples of PAS resins include not only PAS resins with a linear structure but also PAS resins with a crosslinked structure, for example, polymers in which a partially branched or crosslinked structure is formed by using a small amount of a monomer such as a polyhaloaromatic compound having three or more halogen substituents during condensation polymerization, and polymers in which a low-molecular-weight linear polymer is heated at a high temperature in the presence of oxygen or the like to increase the melt viscosity through oxidative crosslinking or thermal crosslinking, thereby improving moldability. As the PAS resin, a PAS resin with a linear structure and a PAS resin with a crosslinked structure may be used in combination.

[0030] The melt viscosity of the PAS resin measured under conditions of 310°C and a shear rate of 1216 / sec is preferably about 8 to 600 Pa s. From the viewpoint of achieving a good balance between mechanical properties and fluidity, the melt viscosity is particularly preferably 8 to 300 Pa s. A melt viscosity within the above range makes it difficult for the fluidity of the thermoplastic resin composition to decrease during injection molding, facilitating the molding operation and enabling the production of molded articles with sufficiently excellent mechanical strength.

[0031] The PAS resin can be produced by a conventionally known polymerization method. PAS resins produced by a general polymerization method are usually washed several times with water or acetone, and then washed with acetic acid, ammonium chloride, or the like, to remove by-product impurities. As a result, the PAS resin may contain a predetermined amount of carboxyl end groups at its terminals.

[0032] In one embodiment, the aromatic polyamide resin refers to a polyamide resin having an amide bond having an -NHCO- structure in the main chain skeleton, and having an aromatic ring in the main chain. A resin whose main chain is composed only of aromatic rings and amide bonds is called a wholly aromatic polyamide resin (aramid). Examples of aromatic polyamide resins include para-type wholly aromatic polyparaphenylene terephthalamide resins (Kevlar (DuPont Toray Co., Ltd.), Twaron (Teijin Limited), both registered trademarks) obtained by polymerizing p-phenylenediamine and terephthalic acid, meta-type polymetaphenylene isophthalamide resins (Nomex (DuPont Toray Co., Ltd.), Conex (Teijin Limited), both registered trademarks), and resins obtained by copolymerizing para-type wholly aromatic polyparaphenylene terephthalamide with diaminophenylene terephthalamide (Technora, registered trademark, Teijin Limited). Semi-aromatic polyamide resins obtained by polymerizing a combination of aromatic monomers and aliphatic monomers can also be used. Two or more aromatic polyamide resins may be used in combination.

[0033] Aromatic polyamide resins can be obtained by conventionally known methods. For example, para-type wholly aromatic polyamide resins can be obtained by reacting an aromatic dicarboxylic acid dichloride (hereinafter also referred to as "acid chloride") component with an aromatic diamine component in an amide-based polar solvent by low-temperature solution polymerization, interfacial polymerization, or the like. Examples of the aromatic dicarboxylic acid dichloride include terephthalic acid chloride, 2-fluoroterephthalic acid chloride, 2-chloroterephthalic acid chloride, 2-cynoterephthalic acid chloride, 3,4'-oxybis(benzoyl chloride), 4,4'-oxybis(benzoyl chloride), 3,4'-bis(chlorocarbonyl)diphenylmethane, 4,4'-bis(chlorocarbonyl)diphenylmethane, 3,4'-dichlorobenzophenone, 4,4'-dichlorobenzophenone, 3,4'-bis(chlorocarbonyl)diphenyl thioether, 4,4'-bis(chlorocarbonyl)diphenyl thioether, 3,4'-bis(chlorocarbonylsulfone, Examples of aromatic diamines include p-phenylenediamine, 2-fluoroparaphenylenediamine, 2-chloro-paraphenylenediamine, 2-cyanoparaphenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-thiodianiline, 3,4'-thiodianiline, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylsulfone, and 4,4'-diaminodiphenylsulfone.

[0034] In one embodiment, syndiotactic polystyrene is a polystyrene-based polymer having a syndiotactic structure in which phenyl groups in side chains are regularly and alternately arranged on opposite sides of the main chain. Examples include polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p- or t-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene), hydrogenated polystyrene, and copolymers containing these structural units. Considering that the para-position of styrene is easily modified and ion exchange groups are easily introduced, a styrene homopolymer (polystyrene) is particularly preferred. Syndiotactic polystyrenes may be used alone or in combination of two or more. Syndiotactic polystyrene can be obtained by a conventionally known method, for example, by polymerizing styrene monomers while controlling their configuration using a coordination polymerization catalyst.

[0035] The thermoplastic resin composition produced by one embodiment of the manufacturing method includes an elastomer. The elastomer can be used alone or in combination of two or more types. The elastomer contained in the thermoplastic resin composition produced by one embodiment of the manufacturing method is not particularly limited, but preferably includes, for example, an olefin-based copolymer. The olefin-based copolymer is preferably an olefin-based copolymer having at least one functional group selected from the group consisting of epoxy groups, carboxyl groups, carboxylic anhydride groups, amino groups, hydroxyl groups, mercapto groups, isocyanate groups, and vinyl groups. In particular, it is preferable to use an epoxy-group-containing olefin-based copolymer as the elastomer. The epoxy-group-containing olefin-based copolymer is preferably an olefin-based copolymer containing structural units derived from an α-olefin having two or more carbon atoms and structural units derived from a glycidyl ester of an α,β-unsaturated acid. The epoxy-group-containing olefin-based copolymer can be used alone or in combination of two or more types. Hereinafter, (meth)acrylic acid alkyl esters are also referred to as (meth)alkyl acrylates. For example, (meth)acrylic acid glycidyl esters are also referred to as glycidyl (meth)acrylate. In this specification, "(meth)acrylic acid" means both acrylic acid and methacrylic acid, and "(meth)acrylate" means both acrylate and methacrylate.

[0036] The α-olefin having two or more carbon atoms (hereinafter simply referred to as "α-olefin") is not particularly limited and examples thereof include ethylene, propylene, butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 4-methyl-1-hexene, etc., with ethylene being particularly preferred. The α-olefins can be used alone or in combination of two or more. When an elastomer contains structural units derived from an α-olefin, flexibility is easily imparted to molded articles obtained from the thermoplastic resin composition. Improving the flexibility of the molded article by imparting flexibility contributes to improvements in high- and low-temperature impact properties and impact resistance.

[0037] The glycidyl ester of an α,β-unsaturated acid (hereinafter also simply referred to as "glycidyl ester") is not particularly limited, and examples thereof include those having a structure represented by the following general formula (1): (In the formula, R １ represents hydrogen or an alkyl group having 1 to 10 carbon atoms.) Examples of compounds represented by the above general formula (1) include acrylic acid glycidyl ester, methacrylic acid glycidyl ester, and ethacrylic acid glycidyl ester, with methacrylic acid glycidyl ester being particularly preferred. The α,β-unsaturated acid glycidyl esters can be used alone or in combination of two or more. Among them, the epoxy group-containing olefin copolymer is preferably an olefin copolymer further containing a structural unit derived from a (meth)acrylic acid alkyl ester. The (meth)acrylic acid alkyl ester is not particularly limited, but examples thereof include acrylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, n-hexyl acrylate, isobutyl acrylate, n-amyl acrylate, and n-octyl acrylate; and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, n-hexyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, and n-octyl methacrylate. Of these, methyl acrylate is preferred. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

[0038] The epoxy group-containing olefin copolymer can be produced by copolymerization using a conventionally known method. For example, the copolymer can be obtained by copolymerization using a commonly known radical polymerization reaction. The type of epoxy group-containing olefin copolymer is not particularly limited, and it may be, for example, a random copolymer or a block copolymer. Furthermore, the epoxy group-containing olefin copolymer may be an olefin graft copolymer in which, for example, polymethyl methacrylate, polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, poly2-ethylhexyl acrylate, polystyrene, polyacrylonitrile, acrylonitrile-styrene copolymer, butyl acrylate-styrene copolymer, or the like is chemically bonded to the olefin copolymer in a branched or crosslinked structure.

[0039] More specifically, examples of epoxy group-containing olefin copolymers include glycidyl methacrylate-modified ethylene copolymers and glycidyl ether-modified ethylene copolymers, with glycidyl methacrylate-modified ethylene copolymers being preferred. Examples of glycidyl methacrylate-modified ethylene copolymers include glycidyl methacrylate-graft-modified ethylene polymers, ethylene-glycidyl methacrylate copolymers, ethylene-glycidyl methacrylate-methyl acrylate copolymers, ethylene-glycidyl methacrylate-ethyl acrylate copolymers, ethylene-glycidyl methacrylate-propyl acrylate copolymers, and ethylene-glycidyl methacrylate-butyl acrylate copolymers. Among these, ethylene-glycidyl methacrylate copolymers and ethylene-glycidyl methacrylate-methyl acrylate copolymers are preferred, with ethylene-glycidyl methacrylate-methyl acrylate copolymers being particularly preferred, as they produce particularly excellent metal-resin composite molded articles. Specific examples of ethylene-glycidyl methacrylate copolymers and ethylene-glycidyl methacrylate-methyl acrylate copolymers include "BONDFAST (registered trademark)" (manufactured by Sumitomo Chemical Co., Ltd.) etc. Examples of glycidyl ether-modified ethylene copolymers include glycidyl ether-graft-modified ethylene copolymers and glycidyl ether-ethylene copolymers.

[0040] In order to further improve fluidity, the olefin copolymer preferably further contains at least one olefin copolymer selected from the group consisting of olefin copolymers of ethylene and an α-olefin having 3 or more carbon atoms and olefin copolymers containing structural units derived from an α-olefin having 2 or more carbon atoms and structural units derived from an α,β-unsaturated carboxylic acid alkyl ester. Examples of such olefin copolymers include copolymers of ethylene and an α-olefin having 3 or more carbon atoms, such as ethylene-propylene copolymer, ethylene-1-butene copolymer, and ethylene-octene copolymer, and copolymers of ethylene and an alkyl (meth)acrylate, such as ethylene-ethyl acrylate (EEA) and ethylene-methacrylate.

[0041] The elastomer content is preferably 3.5 parts by weight or more per 100 parts by weight of the thermoplastic resin. Conventionally, a low elastomer content was considered preferable because it reduced the amount of decomposition gas generated during injection molding. However, the thermoplastic resin composition produced by one embodiment of the manufacturing method is characterized by its ability to actively release low-boiling gases, thereby preventing MD adhesion to gas vents formed primarily by high-boiling gases. Therefore, the elastomer content can be 3.5 parts by weight or more per 100 parts by weight of the thermoplastic resin. There is no particular upper limit to the elastomer content, but it can be 20 parts by weight or less, 15 parts by weight or less, or even 13 parts by weight or less per 100 parts by weight of the thermoplastic resin. The relationship between the amount of low-boiling gases and high-boiling gases and the formation of MD will be discussed later.

[0042] The thermoplastic resin composition produced by the production method of one embodiment contains an antioxidant. The antioxidant is an antioxidant substance that has the effect of preventing the oxidation of other substances (in one embodiment, other components contained in the thermoplastic resin composition other than the antioxidant) by being oxidized itself. The antioxidant includes one selected from the group consisting of phenol-based antioxidants, thioether-based antioxidants, phosphorus-based antioxidants, and amine-based antioxidants. The antioxidants can be used alone or in combination of two or more.

[0043] Phenolic antioxidants are compounds whose molecular structure contains at least one hydroxyl-substituted phenyl group, preferably at least one hydroxyl-substituted phenyl group and at least one alkyl-substituted phenyl group. From the viewpoints of reducing MD during injection molding and preventing gas burns in injection-molded articles, compounds having a hydroxyl-substituted phenyl group and a tert-butyl group are preferred as phenolic antioxidants. Of these, compounds having at least one tert-butyl group per phenolic hydroxyl group are preferred. In this case, it is particularly preferred that the phenolic antioxidant has a tert-butyl group bonded to one or more of the two carbon atoms in the ortho position and the two carbon atoms in the meta position relative to the carbon atom to which the phenolic hydroxyl group is bonded. It is more preferred that a tert-butyl group be bonded to at least one of the two carbon atoms in the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded. Furthermore, it is even more preferred that a tert-butyl group be bonded to one of the two carbon atoms in the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded. In addition, antioxidants in which a substituent is bonded to one of the two carbon atoms in the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded are called semi-hindered phenol antioxidants, and those in which substituents are bonded to both carbon atoms are called hindered phenol antioxidants.

[0044] Specific examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, stearyl-(3,5-dimethyl-4-hydroxybenzyl)thioglycolate, stearyl-β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, distearyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, distearyl (4-hydroxy-3-methyl-5-tert-butyl)benzylmalonate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4-hydroxybenzyl-3,5-di-tert-butyl-4-hydroxybenzyl phosphonate, 4-hydroxybenzyl-3,5-di-tert-butyl-4-hydroxybenzyl malonate ... , 4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid]glycol ester, 4,4'-butylidenebis(6-tert-butyl-m-cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethyl Benzene, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, 2-octylthio-4,6-di(4-hydroxy-3,5-di-tert-butyl)phenoxy-1,3,5-triazine, 4,4'-thiobis(6-tert-butyl-m-crylene), azole), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexyldiol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-octylthio-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, 2,2-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,4-bis[(octylthio)methyl]-o-cresol, and the like.

[0045] Thioether antioxidants that can be used as antioxidants are known to be highly effective as antioxidants, and examples of thioether antioxidants include tetrakis[methylene-3-(dodecylthio)propionate]methane, dilauryl-3,3′-thiodipropionate, and distearyl-3,3′-thiodipropionate.

[0046] On the other hand, phosphorus-based antioxidants that can be used as antioxidants are also known to be highly effective as antioxidants. Examples of phosphorus-based antioxidants include bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,4-di-cumylphenyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4′-bisphenylene phosphite, distearylpentaerythritol diphosphite, triphenyl phosphite, and 3,5-di-butyl-4-hydroxybenzylphosphonate diethyl ester. Among these, antioxidants having a high melting point are preferred in order to reduce volatilization and decomposition of the antioxidant, and specifically, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,4-di-cumylphenyl)pentaerythritol diphosphite, etc. can be preferably used.

[0047] Examples of the amine-based antioxidant that can be used in the thermoplastic resin composition produced in one embodiment include 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, P,P'-dioctyldiphenylamine, N,N'-di-naphthyl-p-phenylenediamine, N,N'-diphenyl-1,4-phenylenediamine, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 4-isopropylaminodiphenylamine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, N,N'-di-sec-butyl-1,4-phenylenediamine, and N-phenyl-1-naphthylamine.

[0048] The content of the antioxidant is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the thermoplastic resin. When the content of the antioxidant is appropriate, it is easy to reduce the formation of MD when the thermoplastic resin composition is injection molded, and in particular, it is possible to reduce the amount of MD adhering to the gas vent as well as the MD on the wall surface of the cavity.

[0049] As the antioxidant, a thioether-based antioxidant, a phosphorus-based antioxidant, and an amine-based antioxidant can be mixed and used together with a phenol-based antioxidant. In this case, the content of the phenol-based antioxidant is not particularly limited as long as it does not impair the object of the present invention. Typically, the content of the phenol-based antioxidant is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the antioxidants.

[0050] The thermoplastic resin composition produced by the production method of one embodiment may contain, in addition to the above components, additives such as organic or inorganic fillers, lubricants, nucleating agents, clarifying agents, plasticizers, ultraviolet inhibitors, ultraviolet absorbers, pigments, dyes, flame retardants, antistatic agents, antiburr agents, heat stabilizers, light stabilizers, colorants, silicone oils, carbon black, mold release agents, and crystallization accelerators, as well as other resins, etc. If necessary, one or more of these additives and resins can be kneaded with each component of the thermoplastic resin composition.

[0051]

[0013] In one embodiment, a method for producing a thermoplastic resin composition includes a step of mixing a thermoplastic resin, an elastomer, and an antioxidant. The step of mixing the thermoplastic resin, the elastomer, and the antioxidant is not particularly limited as long as it can uniformly mix the essential or optional components, and can be appropriately selected from conventional methods for producing thermoplastic resin compositions. For example, a method can be used in which the components are melt-kneaded and extruded using a melt-kneading device such as a single-screw or twin-screw extruder, and the resulting resin composition is then processed into a desired form such as powder, flakes, or pellets.

[0052] In one embodiment of the manufacturing method, the mixing step is carried out at an injection rate of 10 cm ３ / sec, mold temperature T above 40 ° C ０ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at temperatures of 0 to 400°C, (T ０ +20) ° C. (low boiling gas) ０ Among the gases having a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ -20) ° C or higher (high boiling point gas) ０ and the thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. Mold temperature T １０ The gases with boiling points of 0 to 400°C are generated when the mixture is injected into a mold at 0°C, retained for 10 minutes, and then injection molded. １０ -20) ° C or higher (high boiling point gas after retention) １０ ; (where a ０ , b ０ and b １０ The unit is μg / g of thermoplastic resin composition, and T０ =T １０ ) and then, the following equations are obtained: [Equation 4] It is preferable to carry out the process so as to satisfy both of the above.

[0053] The thermoplastic resin composition produced by the production method of one embodiment can be molded by injection molding. Here, injection molding is a molding method for resin compositions in which a molten thermoplastic resin is fed into a mold and cooled to form a mold. Injection molding is performed using an injection molding machine. The thermoplastic resin composition is heated and conveyed through an extruder equipped with a cylinder and a screw, injected into a mold at a predetermined injection rate, and pressed in the mold to form an injection-molded article having a predetermined shape. Here, the injection rate is a value representing the volume of molten resin injected per unit time, and is expressed in units of [cm ３ When injection molding a thermoplastic resin composition, molding conditions including cylinder temperature, injection speed, injection rate, etc. are not particularly limited, and injection molding may be performed under any molding conditions as long as a desired injection-molded article can be obtained. For example, when injection molding a thermoplastic resin composition produced by the production method of one embodiment, the mold temperature is set to T ０ °C. During injection molding, various decomposition gases may be generated by heating the thermoplastic resin composition. The generated gases are discharged to the outside of the mold through a gas vent provided in the mold. The discharged gases can be collected and their amount and type can be measured and analyzed. For a method of collecting gases generated during injection molding and an analysis of the amount and type of gases, please refer to the prior art (for example, JP 2019-181890 A). The thermoplastic resin composition produced by the manufacturing method of one embodiment is, for example, injected at an injection rate of 10 cm ３ / sec into the mold, and the mold temperature T ０ The total amount of gases with boiling points of 0 to 400°C that are generated during injection molding at ℃ is defined as c ０ [μg / g of thermoplastic resin composition]. Here, the total amount c of gases with boiling points of 0 to 400°C generated during injection molding is ０The unit of is the amount of gas in μg (micrograms) per 1 g of thermoplastic resin composition injected into the cavity in one shot. Gases with a boiling point of 0 to 400°C generated during injection molding were analyzed, and the total amount of gases with a boiling point of 0 to 400°C generated during injection molding, c ０ Of these, (T ０ +20) ° C. (low boiling gas) ０ [μg / 1 g of thermoplastic resin composition], (T ０ -20) ° C or higher (high boiling point gas) ０ [μg / g of thermoplastic resin composition]. ０ and b ０ The unit of is the above c ０ is the same as T ０ is the mold temperature in degrees Celsius. (T ０ -20)℃ or higher (T ０ Gases having a boiling point below +20°C are ０ Also ０ Therefore, a ０ +b ０ The value of c ０ is equal to or c ０ The total amount of gases with boiling points between 0 and 400°C generated during injection molding is c ０ Of these, (T ０ +20) ° C. ０ and (T ０ Amount of gas with a boiling point of -20°C or higher b ０ can be measured using an analytical device that qualitatively and / or quantitatively analyzes gases having a boiling point of 0 to 400°C that are generated during injection molding, such as gas chromatography (GC) (see JP-A-2019-181890 for details). On the other hand, the thermoplastic resin composition produced by the production method of one embodiment is subjected to injection molding at an injection rate of 10 cm ３ / sec. Mold temperature T １０ The thermoplastic resin composition is injected into a mold at a temperature T １０ The total amount of gases with boiling points of 0 to 400°C that are generated during injection molding at ℃ is defined as c １０[μg / g of thermoplastic resin composition]. Here, the total amount c of gases with boiling points of 0 to 400°C generated during injection molding is １０ The unit of is μg (microgram) which is the amount of gas per 1 g of thermoplastic resin composition injected into the cavity in one shot. The gases with a boiling point of 0 to 400°C generated during injection molding were analyzed, and the total amount of gases with a boiling point of 0 to 400°C generated during injection molding (hereinafter referred to as "retention gas"), c １０ Of these, (T １０ +20) ° C. (hereinafter referred to as "low boiling point gas after retention") １０ [μg / 1 g of thermoplastic resin composition], (T １０ -20) ° C. or higher (hereinafter referred to as "high boiling point gas after retention") １０ [μg / g of thermoplastic resin composition]. １０ and b １０ The unit of is the above c １０ is the same as T １０ is the mold temperature in degrees Celsius, and the above T ０ It is equal to (T １０ -20)℃ or higher (T １０ Gases having a boiling point below +20°C are １０ Also １０ Therefore, a １０ +b １０ The value of c １０ is equal to or c １０ becomes larger than

[0054] When the thermoplastic resin composition produced by the production method of one embodiment is injection molded under predetermined conditions, the ratio of the amount of low boiling gas to the amount of high boiling gas, and the amount of high boiling gas after retention to the amount of high boiling gas is particularly focused, and the ratio is calculated based on the following formulas: [Mathematical Formula 5] The above formula (i) satisfies the condition that the injection rate (10 cm ３This indicates that when a thermoplastic resin composition is injection molded at a temperature of 1 / sec, the thermoplastic resin composition is retained in the mold for a predetermined time (10 minutes) and then injection molded, and the ratio of the amount of high-boiling gas (high-boiling gas after retention) collected in the gas vent to the amount of high-boiling gas collected in the gas vent when the thermoplastic resin composition is injection molded as usual without retaining it in the mold is below a predetermined value. The ratio in the above formula (i) is more preferably 2.0 or less. Furthermore, the above formula (ii) means that of the total amount of gases with boiling points of 0 to 400°C generated during normal injection molding, the amount of low-boiling gas is greater than the amount of high-boiling gas. Among the decomposition gases generated during injection molding, high-boiling gases are likely to form MD in gas vents, etc., so conventionally, efforts have focused on how to reduce the generation of high-boiling gases. That is, among gas components, high-boiling gases (gases with high boiling points that only reach a gaseous state at high temperatures. When cooled from a gaseous state, they condense and solidify even at relatively high temperatures, even with a slight drop in temperature) cool on the spot when they come into contact with a mold or the like, and the cooled high-boiling gas adheres to the spot and is likely to form MD. On the other hand, low-boiling gases (gases with low boiling points that remain in a gaseous state even at relatively low temperatures. When cooled from a gaseous state, they do not condense and solidify until the temperature drops to a relatively low level) do not precipitate as MD even when they come into contact with a mold or the like unless they are cooled below their low boiling point, and therefore are less likely to adhere to the spot. The inventors analyzed gases collected in gas vents and thoroughly investigated the mechanism of MD formation, and found that it is extremely difficult to completely eliminate the generation of high-boiling gases during injection molding of thermoplastic resin compositions. On the other hand, when comparing thermoplastic resin compositions with the same amount of high-boiling gas but different amounts of low-boiling gas, it was found that thermoplastic resin compositions with a higher amount of low-boiling gas are less likely to form MD. This is thought to be because the low boiling point gas reduces the probability that the high boiling point gas will come into contact with the mold, etc. Furthermore, even if the high boiling point gas does come into contact with the mold, etc., we also found that the low boiling point gas can remove the high boiling point gas (i.e., "sweep away" or "blow away") before it forms MD.

[0055] Each of the following formulas: According to the formula (i), the above formula (i) means that the post-retention gas may contain a certain amount of high-boiling-point gas. When a thermoplastic resin composition is retained in a mold for a predetermined time, the thermoplastic resin composition heated during retention is more likely to undergo a thermal decomposition reaction. Therefore, when injection molding is subsequently performed, the total amount of decomposition gas (post-retention gas) collected in the gas vent tends to increase. However, as described above, it is not possible to completely suppress the generation of high-boiling-point gas during injection molding of a thermoplastic resin composition. The thermoplastic resin composition produced by the manufacturing method of one embodiment is a thermoplastic resin composition having thermal durability such that the amount of high-boiling-point gas generated after retention does not increase sharply even under conditions in which the composition is retained in a mold for a predetermined time. On the other hand, the above formula (ii) means that the thermoplastic resin composition produced by the manufacturing method of one embodiment generates a larger amount of low-boiling-point gas than the amount of high-boiling-point gas generated during normal injection molding, which is very important for achieving the technical effect of one embodiment. As described above, by generating a larger amount of low-boiling gas than high-boiling gas, the probability of high-boiling gas coming into contact with gas vents, molds, etc. is reduced, and adhesion of the high-boiling gas that comes into contact with the gas vent and the subsequent formation of MD can be prevented. Preventing the formation of MD in the gas vent and the resulting clogging of the gas vent can prevent gas burns on the surface of the injection-molded body.

[0056] In the past, when a thermoplastic resin composition containing a thioether-based antioxidant or a phosphorus-based antioxidant is injection molded, it has been said that the thioether-based antioxidant or the phosphorus-based antioxidant itself is likely to cause MD formation. This was thought to be because many thioether-based antioxidants and phosphorus-based antioxidants have relatively low heat resistance compared to phenol-based antioxidants. However, based on the above-mentioned studies by the present inventors, it has been found that any antioxidant can be used in the manufacturing method of one embodiment by selecting a combination of antioxidants that controls the amount of low-boiling gas and high-boiling gas generated.

[0057] In one embodiment of the manufacturing method, the technical significance lies in selecting and mixing a combination of thermoplastic resin, elastomer, and antioxidant so as to satisfy both the above formula (i) and formula (ii). It is not appropriate to set the injection molding temperature so low that it impairs the fluidity of the thermoplastic resin composition in order to suppress the decomposition of the elastomer, which is relatively susceptible to decomposition during high-temperature injection molding. Furthermore, reducing the amount of such elastomer is also not appropriate for obtaining a desired thermoplastic resin composition. As described above, a combination of thermoplastic resin, elastomer, and antioxidant can be selected so as to maximize the amount of low-boiling gas generated during injection molding of the thermoplastic resin composition while suppressing the generation of high-boiling gas. For example, one method for this is to individually analyze the gases generated by each component upon heating and select those that generate more low-boiling gases than high-boiling gases. However, it is not efficient to randomly analyze a large number of thermoplastic resins, elastomers, antioxidants, etc. Those skilled in the art can narrow down the candidate components to a certain extent in advance by checking heat resistance indicators such as thermal decomposition temperature and boiling point published in catalogs or safety data sheets (SDS) issued by the manufacturers of each component, or by roughly estimating the heat resistance from each component's chemical structure. Furthermore, for elastomers, for example, the amount of low-boiling gases can be estimated from impurities derived from the production method (e.g., emulsifiers in emulsion polymerization). Gas analysis of thermoplastic resin compositions produced using the candidate components selected in this manner may also be performed. When injection molding is performed using a thermoplastic resin composition produced based on this technical concept, the formation of MD in the gas vent can be significantly reduced, making it possible to efficiently produce high-quality injection-molded articles with no or minimal gas burns, regardless of the mold temperature. That is, when injection-molded articles are produced using a thermoplastic resin composition produced by one embodiment of the manufacturing method, gas burns on the surface of the injection-molded article, which can occur due to the adhesion of MD to the gas vent, are unlikely to occur, even when continuous injection molding is performed over a long period of time. This is thought to be because the MD to the gas vent is reduced, making the gas vent less likely to be narrowed or clogged.Good gas discharge during injection molding can be easily maintained for a long period of time, and as a result, there is an effect that gas burns in the injection molded article and deterioration of the mold are less likely to occur.

[0058] A second embodiment is a method for determining the moldability of a thermoplastic resin composition containing one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant. The thermoplastic resin composition for which moldability is determined in the second embodiment contains one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant. The thermoplastic resin composition for which moldability is determined in the second embodiment may contain the thermoplastic resin, elastomer, and antioxidant described in the first embodiment. Furthermore, the thermoplastic resin composition for which moldability is determined in the second embodiment may contain, in addition to the above components, additives such as organic or inorganic fillers, lubricants, nucleating agents, clarifying agents, plasticizers, ultraviolet protection agents, ultraviolet absorbers, pigments, dyes, flame retardants, antistatic agents, antiburrs, heat stabilizers, light stabilizers, colorants, silicone oils, carbon black, mold release agents, and crystallization accelerators, as well as other resins, as needed.

[0059] The method for determining the moldability of the thermoplastic resin composition of the second embodiment is to perform an injection molding at an injection rate of 10 cm ３ / sec, mold temperature T above 40 ° C ０ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at temperatures of 0 to 400°C, (T ０ +20) ° C. (low boiling gas) ０ Among the gases having a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ -20) ° C or higher (high boiling point gas) ０ and the thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. Mold temperature T １０ The gases with boiling points of 0 to 400°C are generated when the mixture is injected into a mold at 0°C, retained for 10 minutes, and then injection molded. １０-20) ° C or higher (high boiling point gas after retention) １０ ; (where a ０ , b ０ and b １０ The unit is μg / g of thermoplastic resin composition, and T ０ =T １０ ) and then, the following equations: [Equation 7] In the second embodiment, the method further includes a step of determining that the moldability of the thermoplastic resin composition is good when both of the above conditions are satisfied. ３ / sec into the mold, and the mold temperature T ０ The total amount of gases with boiling points of 0 to 400°C that are generated during injection molding at ℃ is defined as c ０ [μg / g of thermoplastic resin composition]. Here, the total amount c of gases with boiling points of 0 to 400°C generated during injection molding is ０ The unit of is the amount of gas in μg (micrograms) per 1 g of thermoplastic resin composition injected into the cavity in one shot. Gases with a boiling point of 0 to 400°C generated during injection molding were analyzed, and the total amount of gases with a boiling point of 0 to 400°C generated during injection molding, c ０ Of these, (T ０ +20) ° C. (low boiling gas) ０ [μg / 1 g of thermoplastic resin composition], (T ０ -20) ° C or higher (high boiling point gas) ０ [μg / g of thermoplastic resin composition]. ０ and b ０ The unit of is the above c ０ is the same as T ０ is the mold temperature in degrees Celsius. (T ０ -20)℃ or higher (T ０ Gases having a boiling point below +20°C are ０ Also ０ Therefore, a ０ +b ０ The value of c ０ is equal to or c ０The total amount of gases with boiling points between 0 and 400°C generated during injection molding is c ０ Of these, (T ０ +20) ° C. ０ and (T ０ Amount of gas with a boiling point of -20°C or higher b ０ can be measured using an analytical device that qualitatively and / or quantitatively analyzes gases having a boiling point of 0 to 400°C that are generated during injection molding, such as gas chromatography (GC) (see JP-A-2019-181890 for details). On the other hand, when the thermoplastic resin composition is injected into a mold at an injection rate of, for example, 10 cm ３ / sec. Mold temperature T １０ The thermoplastic resin composition is injected into a mold at a temperature T １０ The total amount of gases with boiling points of 0 to 400°C that are generated during injection molding at ℃ is defined as c １０ [μg / g of thermoplastic resin composition]. Here, the total amount c of gases with boiling points of 0 to 400°C generated during injection molding is １０ The unit of is μg (microgram) which is the amount of gas per 1 g of thermoplastic resin composition injected into the cavity in one shot. The gases with a boiling point of 0 to 400°C generated during injection molding were analyzed, and the total amount of gases with a boiling point of 0 to 400°C (post-retention gases) generated during injection molding was calculated. １０ Of these, (T １０ +20) ° C. (low boiling point gas after retention) １０ [μg / 1 g of thermoplastic resin composition], (T １０ -20) ° C or higher (high boiling point gas after retention) １０ [μg / g of thermoplastic resin composition]. １０ and b １０ The unit of is the above c １０ is the same as T １０ is the mold temperature in degrees Celsius, and the above T ０ It is equal to (T １０ -20)℃ or higher (T １０ Gases having a boiling point below +20°C are １０ Also １０Therefore, a １０ +b １０ The value of c １０ is equal to or c １０ becomes larger than

[0060] When a thermoplastic resin composition is injection molded under predetermined conditions, the ratio of the amount of low boiling gas to the amount of high boiling gas, and the amount of high boiling gas after retention to the amount of high boiling gas is particularly taken into consideration, and the ratio is calculated based on the following formulas: [Mathematical Formula 8] When both of the above are satisfied, it can be determined that the moldability of the thermoplastic resin composition is good. ３ This indicates that when a thermoplastic resin composition is injection molded at a temperature of 1000 rpm (1 / sec), the thermoplastic resin composition is allowed to reside in the mold for a predetermined time (10 minutes) and then injection molded, and the ratio of the amount of high-boiling gas collected in the gas vent (high-boiling gas after residence) to the amount of high-boiling gas collected in the gas vent when the thermoplastic resin composition is injection molded in the normal manner without residence in the mold is not more than a predetermined value. The ratio in the above formula (i) is more preferably 2.0 or less. Furthermore, the above formula (ii) means that, of the total amount of gases with boiling points of 0 to 400°C generated during normal injection molding, the amount of low-boiling gas is greater than the amount of high-boiling gas.

[0061] The above formula (i) means that the post-retention gas may contain a certain amount of high-boiling-point gas. When a thermoplastic resin composition is retained in a mold for a predetermined time, the thermoplastic resin composition heated during retention is more likely to undergo a thermal decomposition reaction. Therefore, when injection molding is subsequently performed, the total amount of decomposition gas (post-retention gas) collected in the gas vent tends to increase. However, as described above, it is not possible to completely suppress the generation of high-boiling-point gas during injection molding of a thermoplastic resin composition. In the evaluation method of the second embodiment, one indicator can be whether the thermoplastic resin composition has thermal durability such that the amount of high-boiling-point gas generated after retention does not increase sharply even under conditions where the thermoplastic resin composition is retained in a mold for a predetermined time. On the other hand, the above formula (ii) means that the thermoplastic resin composition generates a larger amount of low-boiling-point gas than the amount of high-boiling-point gas generated during normal injection molding. As described above, by increasing the amount of low-boiling gas generated relative to the amount of high-boiling gas generated, the probability of high-boiling gas contacting gas vents, molds, etc. is reduced, preventing adhesion of the high-boiling gas upon contact and subsequent MD formation. Considering this mechanism of MD formation suppression, the above formula (ii) can also be used as another guideline in determining the moldability of a thermoplastic resin composition. Thus, whether or not both formulas (i) and (ii) are satisfied is determined in advance, and if both formulas are satisfied, it can be determined that the thermoplastic resin composition can be molded well. A thermoplastic resin composition determined in this way can prevent MD formation in gas vents and the resulting clogging of the gas vents during injection molding, and can prevent gas burns on the surface of injection-molded articles.

[0062] A third embodiment is a thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of the elastomer, comprising one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant. The thermoplastic resin composition of the third embodiment may comprise the thermoplastic resin, elastomer, and antioxidant described in the first embodiment. Furthermore, the thermoplastic resin composition of the third embodiment may optionally contain additives such as organic or inorganic fillers, lubricants, nucleating agents, clarifying agents, plasticizers, ultraviolet protection agents, ultraviolet absorbers, pigments, dyes, flame retardants, antistatic agents, antiburrs, heat stabilizers, light stabilizers, colorants, silicone oils, carbon black, mold release agents, and crystallization accelerators, as well as other resins. The thermoplastic resin composition of the third embodiment is intended for molding at a temperature equal to or higher than the decomposition temperature of the elastomer contained in the thermoplastic resin composition.

[0063] The thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of the elastomer of the third embodiment has an injection rate of 10 cm ３ / sec, mold temperature T above 40 ° C ０ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at temperatures of 0 to 400°C, (T ０ +20) ° C. (low boiling gas) ０ Among the gases having a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ -20) ° C or higher (high boiling point gas) ０ and the thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. Mold temperature T １０ The gases with boiling points of 0 to 400°C are generated when the mixture is injected into a mold at 0°C, retained for 10 minutes, and then injection molded. １０ -20) ° C or higher (high boiling point gas after retention) １０ ; (where a ０ , b ０ and b １０ The unit is μg / g of thermoplastic resin composition, and T ０ =T １０) and then, the following equations are obtained: [Equation 9] The thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of the elastomer of the third embodiment is injected at an injection rate of, for example, 10 cm ３ / sec into the mold, and the mold temperature T ０ The total amount of gases with boiling points of 0 to 400°C that are generated during injection molding at ℃ is defined as c ０ [μg / g of thermoplastic resin composition]. Here, the total amount c of gases with boiling points of 0 to 400°C generated during injection molding is ０ The unit of is the amount of gas in μg (micrograms) per 1 g of thermoplastic resin composition injected into the cavity in one shot. Gases with a boiling point of 0 to 400°C generated during injection molding were analyzed, and the total amount of gases with a boiling point of 0 to 400°C generated during injection molding, c ０ Of these, (T ０ +20) ° C. (low boiling gas) ０ [μg / 1 g of thermoplastic resin composition], (T ０ -20) ° C or higher (high boiling point gas) ０ [μg / g of thermoplastic resin composition]. ０ and b ０ The unit of is the above c ０ is the same as T ０ is the mold temperature in degrees Celsius. (T ０ -20)℃ or higher (T ０ Gases having a boiling point below +20°C are ０ Also ０ Therefore, a ０ +b ０ The value of c ０ is equal to or c ０ The total amount of gases with boiling points between 0 and 400°C generated during injection molding is c ０ Of these, (T ０ +20) ° C. ０ and (T ０ Amount of gas with a boiling point of -20°C or higher b ０can be measured using an analytical device that qualitatively and / or quantitatively analyzes gases having a boiling point of 0 to 400°C that are generated during injection molding, such as gas chromatography (GC) (see JP-A-2019-181890 for details). On the other hand, when the thermoplastic resin composition is injected into a mold at an injection rate of, for example, 10 cm ３ / sec. Mold temperature T １０ The thermoplastic resin composition is injected into a mold at a temperature T １０ The total amount of gases with boiling points of 0 to 400°C that are generated during injection molding at ℃ is defined as c １０ [μg / g of thermoplastic resin composition]. Here, the total amount c of gases with boiling points of 0 to 400°C generated during injection molding is １０ The unit of is μg (microgram) which is the amount of gas per 1 g of thermoplastic resin composition injected into the cavity in one shot. The gases with a boiling point of 0 to 400°C generated during injection molding were analyzed, and the total amount of gases with a boiling point of 0 to 400°C (post-retention gases) generated during injection molding was calculated. １０ Of these, (T １０ +20) ° C. (low boiling point gas after retention) １０ [μg / 1 g of thermoplastic resin composition], (T １０ -20) ° C or higher (high boiling point gas after retention) １０ [μg / g of thermoplastic resin composition]. １０ and b １０ The unit of is the above c １０ is the same as T １０ is the mold temperature in degrees Celsius, and the above T ０ It is equal to (T １０ -20)℃ or higher (T １０ Gases having a boiling point below +20°C are １０ Also １０ Therefore, a １０ +b １０ The value of c １０ is equal to or c １０ becomes larger than

[0064] When a thermoplastic resin composition is injection molded under predetermined conditions, the ratio of the amount of low boiling gas to the amount of high boiling gas, and the amount of high boiling gas after retention to the amount of high boiling gas is particularly taken into consideration, and the ratio is calculated based on the following formulas: [Mathematical Formula 10] The above formula (i) satisfies the following conditions: ３ This indicates that when a thermoplastic resin composition is injection molded at a temperature of 1000 rpm (1 / sec), the thermoplastic resin composition is allowed to reside in the mold for a predetermined time (10 minutes) and then injection molded, and the ratio of the amount of high-boiling gas collected in the gas vent (high-boiling gas after residence) to the amount of high-boiling gas collected in the gas vent when the thermoplastic resin composition is injection molded in the normal manner without residence in the mold is not more than a predetermined value. The ratio in the above formula (i) is more preferably 2.0 or less. Furthermore, the above formula (ii) means that, of the total amount of gases with boiling points of 0 to 400°C generated during normal injection molding, the amount of low-boiling gas is greater than the amount of high-boiling gas.

[0065] The above formula (i) means that the post-retention gas may contain a certain amount of high-boiling-point gas. When a thermoplastic resin composition is retained in a mold for a predetermined time, the thermoplastic resin composition heated during retention is more likely to undergo a thermal decomposition reaction. Therefore, when injection molding is subsequently performed, the total amount of decomposition gas (post-retention gas) collected in the gas vent tends to increase. However, as described above, it is not possible to completely suppress the generation of high-boiling-point gas during injection molding of a thermoplastic resin composition. In the evaluation method of the second embodiment, one indicator can be whether the thermoplastic resin composition has thermal durability such that the amount of high-boiling-point gas generated after retention does not increase sharply even under conditions where the thermoplastic resin composition is retained in a mold for a predetermined time. On the other hand, the above formula (ii) means that the thermoplastic resin composition generates a larger amount of low-boiling-point gas than the amount of high-boiling-point gas generated during normal injection molding. As described above, by generating a larger amount of low-boiling gas than high-boiling gas, the probability of high-boiling gas coming into contact with gas vents, molds, etc. is reduced, and adhesion of the high-boiling gas that comes into contact and subsequent formation of MD can be prevented, making it possible to mold the thermoplastic resin composition of the third embodiment at a temperature equal to or higher than the decomposition temperature of the elastomer. The thermoplastic resin composition of the third embodiment can prevent MD formation in gas vents and the resulting clogging of the gas vents during injection molding, and can prevent gas burns on the surface of injection-molded articles.

[0066] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0067] [Preparation of Thermoplastic Resin Composition] The following raw material components were dry-blended, then charged into a twin-screw extruder at a cylinder temperature of 320°C, melt-kneaded, and pelletized to obtain a thermoplastic resin composition. The blending amount (parts by mass) of each component is as shown in Table 1. Thermoplastic resin PPS-1: Polyphenylene sulfide resin, Fortron KPS (product name), Kureha Corporation, melt viscosity: 30 Pa·s (shear rate: 1200 / sec, temperature: 310°C) PPS-2: Polyphenylene sulfide resin, Fortron KPS (product name), Kureha Corporation, melt viscosity: 130 Pa·s (shear rate: 1200 / sec, temperature: 310°C) Elastomer PPS-3: Polyphenylene sulfide resin, Fortron KPS (product name), Kureha Corporation, melt viscosity: 20 Pa·s) (shear rate: 1200 / sec, temperature: 310°C) Olefin copolymer 1 (elastomer 1): Bondfast 7L (product name), Sumitomo Chemical Co., Ltd., contains 70 parts by mass of ethylene, 3 parts by mass of glycidyl methacrylate, and 27 parts by mass of methyl acrylate as copolymerization components. Olefin copolymer 2 (elastomer 2): Modiper A4400 (product name), NOF Corporation, a copolymer obtained by grafting 30 parts by weight of a styrene / acrylonitrile copolymer onto 70 parts by weight of an ethylene / glycidyl methacrylate copolymer. Olefin copolymer 3 (elastomer 3): Modiper A4300 (product name), NOF Corporation, a copolymer obtained by grafting 30 parts by weight of a methyl methacrylate / butyl acrylate copolymer onto 70 parts by weight of an ethylene / glycidyl methacrylate copolymer. Antioxidants Antioxidant 1: IRGANOX 1010 (product name), BASF Japan Ltd., a hindered phenol-based antioxidant (tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane). Antioxidant 2: IRGANOX 245 (product name), BASF Japan Ltd., semi-hindered phenol-based antioxidant (triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate]) Antioxidant 3: Adekastab AO-40 (product name), ADEKA Corporation, semi-hindered phenol-based antioxidant (4,Antioxidant 4: Adekastab AO-30 (product name), ADEKA Corporation, semi-hindered phenolic antioxidant (1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane) Antioxidant 5: Sumilizer GA-80 (product name), Sumitomo Chemical Co., Ltd., semi-hindered phenolic antioxidant (3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane) Antioxidant 6: Adekastab PEP-36 (product name), ADEKA Corporation, hindered phenol-based antioxidant (bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite) Antioxidant 7: ADK STAB AO-412S (product name), ADEKA Corporation, thioether-based antioxidant (tetrakis[methylene 3-dodecylthio)propionate]methane) Glass fiber Glass fiber 1: chopped strand ECS03T-747H (product name), Nippon Electric Glass Co., Ltd. Glass fiber 2: chopped strand ECS03T-717 (product name), Nippon Electric Glass Co., Ltd. Glass fiber 3: chopped strand ECS03T-747 (product name), Nippon Electric Glass Co., Ltd. Calcium carbonate: Whitelon P-30 (product name), Toyo Fine Chemical Co., Ltd.

[0068] [Evaluation of Gas Burning Occurrence] Using the thermoplastic resin composition prepared above, an injection molding machine (FANUC ROBOSHOT S2000i30A, FUNAC Corporation, screw diameter 16 mm) was used to perform gas burning at a cylinder temperature of 320°C, a mold temperature of 140°C, an injection speed of 50 mm / sec, an injection time of 2 seconds, a cooling time of 10 seconds, and an injection rate of 10 cm ３Continuous injection molding was performed under conditions of 1 / sec, yielding injection-molded articles. The injection molding machine used a mold equipped with a gas vent having a thickness of 7 μm and a width of 4 mm in the vent section. Continuous injection molding was performed under the above conditions, and the number of shots at which gas burns began to occur in the resulting injection-molded articles was counted. A large number of shots at which gas burns occurred means that gas burns did not occur easily even after multiple injection moldings, while a small number of shots at which gas burns occurred means that gas burns began to occur at an early stage of continuous injection molding. When the number of shots at which gas burns occurred exceeded 200, the moldability was judged to be good, and when the number of shots at which gas burns occurred was less than 200, the moldability was judged to be poor. The evaluation results are shown in Tables 1 and 2.

[0069] [Analysis of Gas Generated During Injection Molding] When obtaining an injection-molded article according to the method described above for evaluating gas burn occurrence, the gas generated up to the stage where a predetermined number of injection moldings were performed before gas burn occurrence was vacuum-collected using an exhaust gas collection tube. This gas collection method allowed almost complete recovery of the gas generated during molding, preventing loss due to adhesion to the mold. The collected gas was analyzed by gas chromatography (GC, column used: Agilent Technologies DB5-MS, heating rate 10 ° C / min) following the method described in JP 2019-181890 A. All gases had boiling points between 0 and 400 ° C. Components with retention times of less than 16 minutes on the GC chart (components with boiling points less than 160 ° C.) were considered low-boiling gases, and the amount of low-boiling gas was calculated from the peak area on the GC chart. On the other hand, components with a retention time of 12 minutes or more (components with a boiling point of 120°C or more) were considered to be high-boiling gases, and the amount of high-boiling gases was calculated from the peak area of ​​the GC chart. Finally, the amount of gas collected during a predetermined number of injection moldings was divided by the total weight of the molded bodies obtained by the predetermined number of injection moldings to obtain c ０ The amount of low boiling gas [μg / g of thermoplastic resin composition] was calculated, and divided by the total weight of the molded body obtained by a predetermined number of injection moldings to obtain a ０ [μg / g of thermoplastic resin composition] was calculated, and the amount of high boiling point gas was divided by the total weight of the molded body obtained by a predetermined number of injection moldings to obtain b ０The [μg / g of thermoplastic resin composition] was calculated. Furthermore, separately from the above, a thermoplastic resin composition was injected once under the same conditions as above, and the thermoplastic resin composition was allowed to remain in the mold for 10 minutes. The injection molding machine was then operated once, and the gas generated during injection molding was vacuum-collected using an exhaust gas collection tube. This gas collection method allowed for almost complete recovery of the gas generated during molding, preventing loss due to adhesion to the mold. The generated gas was analyzed by gas chromatography (GC, column used: Agilent Technologies DB5-MS, heating rate 10°C / min). Components with a retention time of less than 16 minutes on the GC chart (components with a boiling point of less than 160°C) were defined as low-boiling gases after retention, and the amount of low-boiling gases after retention was calculated from the peak area on the GC chart. Meanwhile, components with a retention time of 12 minutes or longer (components with a boiling point of 120°C or higher) were defined as high-boiling gases after retention, and the amount of high-boiling gases after retention was calculated from the peak area on the GC chart. Finally, the amount of collected gas is divided by the weight of the injection molded article to obtain c １０ The amount of the low boiling point gas after retention [μg / g of thermoplastic resin composition] was calculated, and the amount of the low boiling point gas after retention was divided by the weight of the injection-molded article to obtain a １０ [μg / g of thermoplastic resin composition] was calculated, and the amount of the retained high boiling point gas was divided by the weight of the injection-molded article to obtain b １０ The mass (μg / g of thermoplastic resin composition) was calculated.

[0070]

[0071] As can be seen from Table 1, the thermoplastic resin compositions of the present invention (Examples 1 to 8), which contained a thermoplastic resin, an elastomer, and an antioxidant and satisfied both the above formulas (i) and (ii), exhibited a large number of shots that generated gas burns and good moldability. Furthermore, the thermoplastic resin compositions of Examples 2 and 4 to 6, which contained semi-hindered phenolic antioxidants (Antioxidants 2 to 4), tended to generate more low-boiling gases and suppress the generation of high-boiling gases during injection molding than the thermoplastic resin compositions of Examples 1, 3, and 7, which contained hindered phenolic antioxidants (Antioxidants 1 and 5), and Example 8, which contained a thioether-based antioxidant (Antioxidant 6). As a result, the thermoplastic resin compositions of Examples 2 and 4 to 6 exhibited a higher number of shots that generated gas burns, suggesting that the semi-hindered phenolic antioxidants contained in the thermoplastic resins of these Examples can more effectively suppress gas burns in thermoplastic resin compositions.

[0072] As shown in Table 2, when thermoplastic resin compositions not containing an antioxidant (Comparative Examples 1 and 2) were injection molded, gas burning occurred relatively quickly. Furthermore, when thermoplastic resin compositions containing a thermoplastic resin, an elastomer, and an antioxidant but not satisfying either formula (i) or formula (ii) defined in the present invention (Comparative Examples 4, 5, and 6), and a thermoplastic resin composition not satisfying both formulas (i) and (ii) (Comparative Example 3), were injection molded, the number of shots in which gas burning occurred was also small. Tables 1 and 2 indicate that whether or not formulas (i) and (ii) are satisfied is closely linked to the number of shots in which gas burning occurred. In other words, when combining a specific thermoplastic resin, elastomer, and antioxidant, it is important to consider whether or not both formulas (i) and (ii) are satisfied in order to obtain a thermoplastic resin composition with excellent injection moldability.

Claims

1. A method for determining moldability of a thermoplastic resin composition containing one or more thermoplastic resins selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant, comprising the steps of: Mold temperature T above 40°C ０ The thermoplastic resin composition was injected at a rate of 10 cm ３ Among the gases with boiling points of 0 to 400°C that are generated during injection molding at 1000 / sec, (T ０ +20) ° C. ０ ; Among the gases having a boiling point of 0 to 400°C that are generated during the injection molding, (T ０ The amount of gas having a boiling point of -20°C or higher is b ０ ;year, The thermoplastic resin composition was injected at an injection rate of 10 cm ３ / sec. mold temperature T １０ The gas having a boiling point of 0 to 400°C is generated when the mixture is injected into a mold at 0°C, retained for 10 minutes, and then injection molded. １０ The amount of gas having a boiling point of -20°C or higher is b １０ ; (where a ０ , b ０ and b １０ The unit of is μg / g of thermoplastic resin composition, and T ０ = T １０ ) and the following formulas: [Equation 2] b １０ / b ０ ≦2.5 (i) a ０ >b ０ (ii) and determining that the moldability of the thermoplastic resin composition is good when both of the above conditions are satisfied.

2. 2. The method for determining the moldability of a thermoplastic resin composition according to claim 1, wherein the antioxidant comprises one selected from the group consisting of a phenol-based antioxidant, a thioether-based antioxidant, a phosphorus-based antioxidant, and an amine-based antioxidant, and the content of the elastomer is 3.5 parts by weight or more relative to 100 parts by mass of the thermoplastic resin.

3. 3. The method for determining the moldability of a thermoplastic resin composition according to claim 1 or 2, wherein the antioxidant is selected from a phenol-based antioxidant or a thioether-based antioxidant, and the phenol-based antioxidant has a tert-butyl group bonded to at least one of two carbon atoms at the ortho position relative to a carbon atom to which a phenolic hydroxyl group is bonded.

4. The method for determining the moldability of a thermoplastic resin composition according to claim 3, wherein the phenolic antioxidant has a tert-butyl group bonded to any one of two carbon atoms at the ortho position relative to the carbon atom to which the phenolic hydroxyl group is bonded.