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

Abstract

The purpose of the present invention is to provide a thermoplastic resin composition which, when injection-molded at a temperature equal to or higher than the decomposition temperature of an elastomer, in particular in a vent hole, is capable of significantly reducing the formation of mold attachments and the clogging of the vent hole during molding, and which is capable of providing a thermoplastic resin composition which is obtained by compounding an elastomer, thus, the occurrence of gas combustion in an injection molded body can be reduced. Also provided is a method for producing the thermoplastic resin composition. Further, the purpose of the present invention is to provide a method for determining whether or not the operation of injection molding can be stably performed when the thermoplastic resin composition is injection-molded at a temperature equal to or higher than the decomposition temperature of the elastomer. Provided is a method for producing a thermoplastic resin composition containing one or more types of thermoplastic resin selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, an elastomer, and an antioxidant, said thermoplastic resin containing at least one type of thermoplastic resin selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins. The method for producing a thermoplastic resin composition comprises: a step in which a0 is the amount of a gas having a boiling point lower than (T0 + 20) DEG C among gases having a boiling point of 0-400 DEG C generated when injection molding the thermoplastic resin composition at a mold temperature (T0 DEG C) of 40 DEG C or higher at an injection rate of 10 cm < 3 > / sec, and a0 is the amount of a gas having a boiling point lower than (T0 + 20) DEG C; the thermoplastic resin composition is injected into a mold having a mold temperature T10 DEG C of 40 DEG C or more at an injection rate of 10 cm3 / sec, where b0 is the amount of a gas having a boiling point of (T0-20) DEG C or more among the gases having a boiling point of 0-400 DEG C generated during the injection molding, stays for 10 minutes, and then is injection-molded. The thermoplastic resin, the elastomer, and the antioxidant are mixed so that the following expressions are satisfied at the same time, where the amount of the gas having a boiling point of (T10-20) DEG C or higher among the gases having a boiling point of 0-400 DEG C generated at the time is represented by b10 (where a0, b0, and b10 are in [mu] g / 1 g of the thermoplastic resin composition, and T0 = T10). B10 / b0 < = 2.5; (i) a0 > b0 (ii).

Description

Technical Field

[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 higher than the decomposition temperature of an elastomer. In particular, the present invention relates 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 higher than the decomposition temperature of an elastomer. Background Art

[0002] Polyarylene sulfide (hereinafter referred to as "PAS") resin represented by polyphenylene sulfide (hereinafter referred to as "PPS") resin has high heat resistance, mechanical properties, chemical resistance, dimensional stability and flame retardancy. Therefore, PAS resin is widely used for electrical / electronic equipment component materials, automotive equipment component materials, chemical equipment component materials, etc. PAS resin is particularly used as a material for components used at high ambient temperatures.

[0003] In addition, various compositions containing PAS resins have been proposed. Specifically, there are known compositions containing PAS resins and olefin copolymers containing α-olefins and glycidyl esters of α,β-unsaturated acids as main components (e.g., Patent Document 1), and compositions containing PAS resins and olefin copolymers containing ethylene and α-olefins 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 susceptible to thermal degradation at high temperatures. Therefore, when the resin compositions described in Patent Documents 1 and 2 containing thermoplastic elastomers are used for injection molding, a new problem occurs that a large amount of mold deposits (hereinafter sometimes referred to as "mold deposits" or "MD") are easily generated during molding.

[0005] Injection molding is widely used in thermoplastic resins as a cheap and highly productive manufacturing method. In the injection molding of thermoplastic resins, first, by rotating the screw for metering, a granular resin called pellets is filled into a barrel, and the pellets are melted by a heater arranged in the barrel. The molten resin is extruded by the screw, and is filled into the cavity (the entire space of the filled resin inside the mold) in the mold by high-speed injection, and is cooled to obtain an injection molded body. In injection molding, in order not to degrade the resin, the processing temperature is usually set within the range from the melting point (or flowable temperature) of the resin that is the basis of the resin composition to the thermal decomposition temperature. However, due to various reasons, the resin and additives in the thermoplastic resin composition are sometimes decomposed in the molding machine. The decomposition of the resin and the additive not only causes the problem of reduced physical properties caused by the deterioration of the resin itself. The decomposition gas and the air involved in the resin composition during the metering of the resin composition cannot be smoothly discharged from the mold during injection and are compressed in the closed space, forming a high temperature, which may cause the burning of the resin composition. In addition, various substances including decomposition gas generated by decomposition adhere to exhaust holes, mold cavities, etc., and generate MD. As described above, such a problem can be less likely to occur 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 additive in the thermoplastic resin composition), but depending on various circumstances (for example, in order to ensure the fluidity of the thermoplastic resin composition during molding, plasticization is performed at a high temperature to reduce the viscosity of the thermoplastic resin composition, in order to impart specific properties to the molded body, the decomposition temperature of the additive contained is lower than the processing temperature of the basic thermoplastic resin, etc.), injection molding may need to be performed at a temperature exceeding the decomposition temperature of these components.

[0006] As a method for solving the problem of MD formation in vents and cavities, a method of mixing a PAS resin and a specific olefin copolymer (elastomer component) and further mixing a specific antioxidant has been proposed (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 temperature such as a mold temperature of 130° C. to 180° C., MD formation during molding in vents and cavities can be reduced.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2000-263586

[0010] Patent Document 2: Japanese Patent Application Publication No. 2002-179914

[0011] Patent Document 3: WO2017 / 10364 Summary of the invention

[0012] Problem that the invention aims to solve

[0013] However, when using the prior art such as patent documents 1, 2 and 3, when the thermoplastic resin composition is molded at the decomposition temperature of the components of the thermoplastic resin composition or at a temperature exceeding the decomposition temperature, it is sometimes impossible to fully solve the problem of forming MD in the vent and cavity and the problem of gas combustion. That is, in the injection molding of the PAS resin composition disclosed in patent documents 1, 2 and 3, it is difficult to prevent the generation of the decomposition gas itself from the elastomer compounded in the resin composition. Therefore, if the generation of the decomposition gas during molding cannot be avoided, MD may be formed sooner or later. In addition, as a result, due to the narrowing and clogging of the vent, gas combustion may occur in the molded body obtained from the thermoplastic resin composition. Therefore, it has to be said that the injection molding of the PAS resin composition compounded with an elastomer is still difficult.

[0014] The inventors of the present invention, when injection molding a thermoplastic resin composition, collected the gas generated during injection molding and analyzed the type and amount of the gas. As a result, it was found that the gas having a boiling point lower than a temperature 20°C higher than the mold temperature T°C during injection molding (hereinafter referred to as "low-boiling gas") and the gas having a boiling point higher than a temperature 20°C lower than T°C (hereinafter referred to as "high-boiling gas") were collected. Generally, the gas that causes the formation of MD is a high-boiling gas (the details of the mechanism will be described later), so the type and amount of additives that have the effect of preventing the generation of high-boiling gas were studied. However, as described above, when injecting a resin composition in which the generation of decomposition gas is difficult to avoid during molding, such as a PAS resin composition compounded with an elastomer, the generation of high-boiling gas cannot be avoided.

[0015] The present invention is made to solve the above-mentioned problems, and its object is to provide a thermoplastic resin composition, which can significantly reduce the formation of mold attachments and clogging of vent holes during molding, especially in vent holes, when the thermoplastic resin composition mixed with an elastomer is injection molded at a temperature higher than the decomposition temperature of the elastomer, thereby reducing the occurrence of gas combustion of the injection molded body. Furthermore, another object of the present invention is to provide a method for producing such a thermoplastic resin composition. Furthermore, another object of the present invention is to provide a method for determining whether the injection molding operation can be stably performed when the thermoplastic resin composition is injection molded at a temperature higher than the decomposition temperature of the elastomer.

[0016] Solutions for solving problems

[0017] The present inventors have conducted intensive studies to solve the above problems. As a result, they have found that, for a thermoplastic resin composition blended with an elastomer and an antioxidant, by adjusting the type of gas generated when the thermoplastic resin composition is injection molded, it is possible to prevent MD from being formed in the vent hole, thereby completing the present invention. More specifically, the present invention provides the following solutions.

[0018] (1) A method for producing a thermoplastic resin composition, wherein the thermoplastic resin composition comprises a thermoplastic resin, an elastomer and an antioxidant, wherein the thermoplastic resin is at least one selected from the group consisting of a polyarylene sulfide resin, an aromatic polyamide resin and a syndiotactic polystyrene resin, and the method for producing the thermoplastic resin composition comprises the following steps:

[0019] The thermoplastic resin composition is injected at a mold temperature T0°C above 40°C at an injection rate of 10 cm 3 The amount of gas having a boiling point lower than (T0+20)°C among the gas having a boiling point of 0 to 400°C generated during injection molding at 1000 rpm is defined as a0.

[0020] The amount of gas having a boiling point of (T0-20)°C or higher among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0.

[0021] The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point of -20)°C or higher is b 10 ,

[0022] (Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 ), the thermoplastic resin, the elastomer and the antioxidant are mixed in a manner that simultaneously satisfies the following formulas.

[0023] b 10 / b0≤2.5 (i)

[0024] a0>b0 (ii)

[0025] (2) The method for producing a thermoplastic resin composition according to (1), wherein the antioxidant comprises one selected from the group consisting of phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants, and the content of the elastomer is 3.5 parts by weight or more per 100 parts by weight of the thermoplastic resin.

[0026] (3) A method for producing a thermoplastic resin composition according to (1) or (2), wherein the antioxidant is selected from a phenolic antioxidant or a thioether antioxidant, and the phenolic antioxidant has a tert-butyl group bonded to at least one of the two carbon atoms that are ortho-positioned relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0027] (4) The method for producing a thermoplastic resin composition according to (3), wherein the phenolic antioxidant has a tert-butyl group bonded to any one of two carbon atoms at ortho positions relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0028] (5) A method for determining the moldability of a thermoplastic resin composition, wherein the thermoplastic resin composition comprises a thermoplastic resin, an elastomer, and an antioxidant, and the thermoplastic resin is at least one selected from the group consisting of a polyarylene sulfide resin, an aromatic polyamide resin, and a syndiotactic polystyrene resin, wherein:

[0029] The thermoplastic resin composition is injected at a mold temperature T0°C above 40°C at an injection rate of 10 cm 3 The amount of gas having a boiling point lower than (T0+20)°C among the gas having a boiling point of 0 to 400°C generated during injection molding at 1000 rpm is defined as a0.

[0030] The amount of gas having a boiling point of (T0-20)°C or higher among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0.

[0031] The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point of -20)°C or higher is b 10 ,

[0032] (Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 ), when the following formulae are satisfied simultaneously, the moldability of the thermoplastic resin composition is judged to be good.

[0033] b 10 / b0≤2.5 (i)

[0034] a0>b0 (ii)

[0035] (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 phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants, and the content of the elastomer is 3.5 parts by weight or more relative to 100 parts by weight of the thermoplastic resin.

[0036] (7) The method for determining the moldability of a thermoplastic resin composition according to (5) or (6), wherein the antioxidant is selected from a phenolic antioxidant or a thioether antioxidant, and the phenolic antioxidant has a tert-butyl group bonded to at least one of the two carbon atoms that are ortho-positioned relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0037] (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 any one of two carbon atoms ortho to the carbon atom to which the phenolic hydroxyl group is bonded.

[0038] (9) A thermoplastic resin composition comprising a thermoplastic resin, an elastomer, and an antioxidant, wherein the thermoplastic resin is at least one selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins, and the thermoplastic resin composition is used for molding at a temperature not lower than the decomposition temperature of the elastomer.

[0039] The thermoplastic resin composition is injected at a mold temperature T0°C above 40°C at an injection rate of 10 cm 3 The amount of gas having a boiling point lower than (T0+20)°C among the gas having a boiling point of 0 to 400°C generated during injection molding at 1000 rpm is defined as a0.

[0040] The amount of gas having a boiling point of (T0-20)°C or higher among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0.

[0041] The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point of -20)°C or higher is b 10 ,

[0042] (Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 ), and satisfy the following equations.

[0043] b 10 / b0≤2.5 (i)

[0044] a0>b0 (ii)

[0045] (10) The thermoplastic resin composition according to (9), wherein the antioxidant comprises one selected from the group consisting of phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants, and the content of the elastomer is 3.5 parts by weight or more relative to 100 parts by weight of the thermoplastic resin.

[0046] (11) A thermoplastic resin composition according to (9) or (10), wherein the antioxidant is selected from a phenolic antioxidant or a thioether antioxidant, and the phenolic antioxidant has a tert-butyl group bonded to at least one of the two carbon atoms that are ortho-positioned relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0047] (12) The thermoplastic resin composition according to (11), wherein the phenolic antioxidant has a tert-butyl group bonded to any one of two carbon atoms at ortho positions relative to the carbon atom to which the phenolic hydroxyl group is bonded.

[0048] Effects of the Invention

[0049] According to the present invention, a method for producing a thermoplastic resin composition can be provided, which can significantly reduce the formation of MD in vent holes during injection molding and prevent gas combustion of an injection molded body. In addition, a method for determining whether a thermoplastic resin composition can be well molded can be provided. Furthermore, a thermoplastic resin composition can be provided, which can significantly reduce the formation of MD in vent holes during injection molding at a temperature above the decomposition temperature of the components in the thermoplastic resin composition and prevent gas combustion of an injection molded body. DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0051] First, the thermoplastic resin composition produced by the production method of the first embodiment is described. The thermoplastic resin composition produced by the production method of the first embodiment comprises a thermoplastic resin, an elastomer, and an antioxidant, wherein the thermoplastic resin is one or more selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins.

[0052] Polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins used as thermoplastic resins are all known as resins having high heat resistance exceeding 200°C. Among them, polyarylene sulfide resin (PAS resin) is a resin having a linear structure in which arylene groups and sulfur atoms are alternately bonded and composed of a repeating unit -(Ar-S)- ("Ar" represents an arylene group) as the main constituent. Examples of arylene groups contained in PAS resins include p-phenylene, m-phenylene, o-phenylene, substituted phenylene, p,p'-diphenyl sulfone, p,p'-biphenylene, p,p'-diphenylene ether, p,p'-diphenylene carbonyl, naphthyl, etc., and two or more different arylene groups may be contained in the repeating unit. As the polyarylene sulfide resin used in the embodiment, a polyphenylene sulfide (PPS) resin using p-phenylene as the arylene group is preferred. It is known that a homopolymer having a p-phenylene sulfide group as a repeating unit has high heat resistance and exhibits high strength, high rigidity, and high dimensional stability over a wide temperature range.

[0053] As the PAS resin containing two or more different arylene groups in the repeating unit, a resin containing a combination of a p-phenylene sulfide group and a m-phenylene sulfide group is preferably used from the viewpoint of physical properties such as heat resistance, moldability, and mechanics. Among the above resins, a polymer containing a p-phenylene sulfide group at a ratio of 70 mol% or more is more preferred, and a polymer containing a p-phenylene sulfide group at a ratio of 80 mol% or more is further preferred. In addition, among these PAS resins, a high molecular weight polymer having a substantially linear structure that can be obtained by polycondensation of a monomer mainly composed of a bifunctional halogen aromatic compound is particularly preferred. These PAS resins can be used alone or in combination of two or more.

[0054] Examples of PAS resins include, in addition to PAS resins having a linear structure, PAS resins having a cross-linked structure, polymers having a branched structure or a cross-linked structure partially formed by using a small amount of a monomer such as a polyhalogen aromatic compound having three or more halogen substituents during polycondensation, and polymers having improved molding processability by heating a low molecular weight linear polymer at a high temperature in the presence of oxygen or the like to increase the melt viscosity through oxidative cross-linking or thermal cross-linking. As PAS resins, a linear PAS resin and a cross-linked PAS resin may be used in combination.

[0055] The melt viscosity of the PAS resin measured at 310°C and a shear rate of 1216 / sec is preferably about 8 to 600 Pa·s. From the viewpoint of a good balance between mechanical properties and fluidity, the melt viscosity is particularly preferably 8 to 300 Pa·s. If the melt viscosity is within the above range, the fluidity of the thermoplastic resin composition is not easily reduced during injection molding, the molding operation becomes easy, and a molded body with sufficiently excellent mechanical strength can be obtained.

[0056] It should be noted that the PAS resin can be manufactured by a conventionally known polymerization method. The PAS resin manufactured by a general polymerization method is usually washed several times with water or acetone to remove by-product impurities, and then washed with acetic acid, ammonium chloride, etc. As a result, the PAS resin terminal may contain a carboxyl terminal group at a predetermined amount ratio.

[0057] In the first embodiment, the aromatic polyamide resin refers to a polyamide resin having an amide bond having a structure of -NHCO- in the main chain skeleton and having an aromatic ring in the main chain. A resin having a main chain consisting only of an aromatic ring and an amide bond is referred to as a wholly aromatic polyamide resin (aramid). Examples of the aromatic polyamide resin include para-type wholly aromatic poly(p-phenylene terephthalamide) resins obtained by polymerizing p-phenylenediamine and terephthalic acid (Kevlar (DU PONT-TORAY CO., LTD.), Twaron (Teijin Ltd.), both registered trademarks), meta-type poly(m-phenylene isophthalamide) resins (Nomex (DU PONT-TORAY CO., LTD.), Conex (Teijin Ltd.), both registered trademarks), and resins obtained by copolymerizing diaminophenylene terephthalamide and para-type wholly aromatic poly(p-phenylene terephthalamide) (Technola, registered trademark, Teijin Ltd.). Semi-aromatic polyamide resins obtained by polymerizing an aromatic monomer and an aliphatic monomaleic acid ester in combination may also be used. Two or more aromatic polyamide resins may be mixed and used.

[0058] 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 or interfacial polymerization. Here, examples of the aromatic dicarboxylic acid dichloride include terephthaloyl chloride, 2-fluoroterephthaloyl chloride, 2-chloroterephthaloyl chloride, 2-cyanoterephthaloyl 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 sulfide, 4,4'-bis(chlorocarbonyl)diphenyl sulfide, 3,4'-bis(chlorocarbonyl)sulfone, and 4,4'-bis(chlorocarbonyl)diphenyl sulfone. Examples of the aromatic diamine include p-phenylenediamine, 2-fluoro-p-phenylenediamine, 2-chloro-p-phenylenediamine, 2-cyano-p-phenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-thiodiphenylamine, 3,4'-thiodiphenylamine, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl sulfone.

[0059] In the first embodiment, syndiotactic polystyrene refers to a polymer of a polystyrene system having a syndiotactic structure in which the phenyl groups of the side chains are regularly and alternately arranged on the opposite side relative to the main chain. Polystyrene, poly(p-methylstyrene), poly(m-methylstyrene), poly(p- or tert-butylstyrene), poly(p-chlorostyrene), poly(m-chlorostyrene), poly(p-fluorostyrene), hydrogenated polystyrene and copolymers of structural units thereof can be listed. Considering that the para position of styrene is easily modified and easily introduced into ion exchange groups, a homopolymer (polystyrene) of styrene is particularly preferred. Syndiotactic polystyrene can be used alone or in combination of two or more. Syndiotactic polystyrene can be obtained by conventionally known methods, such as by polymerizing while controlling the configuration of styrene monomers using a coordination polymerization catalyst.

[0060] The thermoplastic resin composition manufactured by the manufacturing method of the first embodiment includes an elastomer. The elastomer can be used alone or in combination of two or more. The elastomer contained in the thermoplastic resin composition manufactured by the manufacturing method of the first embodiment is not particularly limited, for example, it is preferably an olefin copolymer. As an olefin copolymer, it is preferably an olefin copolymer having at least one functional group selected from the group consisting of an epoxy group, a carboxyl group, a carboxylic anhydride group, an amino group, a hydroxyl group, a mercapto group, an isocyanate group and a vinyl group. In particular, it is preferred to use an epoxy-containing olefin copolymer as an elastomer. As an epoxy-containing olefin copolymer, it is preferably an olefin copolymer containing a structural unit derived from an α-olefin with a carbon number of 2 or more and a structural unit derived from a glycidyl ester of an α,β-unsaturated acid. The epoxy-containing olefin copolymer can be used alone or in combination of two or more. It should be noted that alkyl (meth)acrylates are also referred to as alkyl (meth)acrylates below. For example, glycidyl (meth)acrylate is also referred to as glycidyl (meth)acrylate. In addition, in this specification, "(meth)acrylic acid" means both acrylic acid and methacrylic acid, and "(meth)acrylate" means both acrylate and methacrylate.

[0061] As α-olefins having more than 2 carbon atoms (hereinafter also referred to as "α-olefins"), there are no particular limitations, and examples thereof include ethylene, propylene, butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, 4-methyl-1-hexene, etc., and ethylene is particularly preferred. One α-olefin may be used alone, or two or more may be used in combination. When the elastomer contains a structural unit derived from an α-olefin, it is easy to impart flexibility to a molded body obtained from a thermoplastic resin composition. Improving the softness of the molded body by imparting flexibility helps to improve high and low temperature impact properties and impact resistance.

[0062] 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).

[0063]

[0064] (Where R 1 represents hydrogen or an alkyl group having 1 to 10 carbon atoms. )

[0065] Examples of the compound represented by the general formula (1) include glycidyl acrylate, glycidyl methacrylate, and glycidyl ethacrylate, and glycidyl methacrylate is particularly preferred. The glycidyl ester of an α,β-unsaturated acid may be used alone or in combination of two or more.

[0066] Among them, the epoxy-containing olefin copolymer is preferably an olefin copolymer further containing a structural unit derived from an alkyl (meth)acrylate. As the alkyl (meth)acrylate, there is no particular limitation, and examples thereof include acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, n-hexyl acrylate, isobutyl acrylate, n-pentyl acrylate, and n-octyl acrylate; and methacrylates such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, n-hexyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, and n-octyl methacrylate. Among them, methyl acrylate is preferred. The alkyl (meth)acrylate may be used alone or in combination of two or more.

[0067] The epoxy-containing olefin copolymer can be manufactured by copolymerization using a conventionally known method. For example, the copolymer can be obtained by copolymerization using a generally known free radical polymerization reaction. The type of epoxy-containing olefin copolymer is not particularly limited, and may be, for example, a random copolymer or a block copolymer. In addition, it may be an olefin graft copolymer formed by chemical bonding with the above-mentioned olefin copolymer in a branched or cross-linked structure such as polymethyl methacrylate, polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyacrylate-2-ethylhexyl, polystyrene, polyacrylonitrile, acrylonitrile-styrene copolymer, butyl acrylate-styrene copolymer, etc.

[0068] As the epoxy-containing olefin copolymer, more specifically, for example, glycidyl methacrylate-modified ethylene copolymers and glycidyl ether-modified ethylene copolymers can be cited, among which glycidyl methacrylate-modified ethylene copolymers are preferred. As the glycidyl methacrylate-modified ethylene copolymers, glycidyl methacrylate-grafted 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, ethylene-glycidyl methacrylate-butyl acrylate copolymers, etc. can be cited. Among them, from the aspect of obtaining particularly excellent metal-resin composite molded bodies, ethylene-glycidyl methacrylate copolymers and ethylene-glycidyl methacrylate-methyl acrylate copolymers are preferred, and ethylene-glycidyl methacrylate-methyl acrylate copolymers are particularly preferred. Specific examples of the ethylene-glycidyl methacrylate copolymer and the ethylene-glycidyl methacrylate-methyl acrylate copolymer include "BondFast (registered trademark)" (manufactured by Sumitomo Chemical Co., Ltd.).

[0069] Examples of the glycidyl ether-modified ethylene copolymer include glycidyl ether graft-modified ethylene copolymers and glycidyl ether-ethylene copolymers.

[0070] In order to further improve fluidity, the olefin copolymer preferably further comprises at least one olefin copolymer selected from the group consisting of an olefin copolymer of ethylene and an α-olefin having more than 3 carbon atoms and an olefin copolymer containing a structural unit derived from an α-olefin having more than 2 carbon atoms and a structural unit derived from an α,β-unsaturated carboxylic acid alkyl ester. Examples of such olefin copolymers include copolymers of ethylene and an α-olefin having more than 3 carbon atoms, such as ethylene-propylene copolymers, ethylene-1-butene copolymers, and ethylene-octene copolymers, and copolymers of ethylene and an alkyl (meth)acrylate, such as ethylene-ethyl acrylate (EEA) and ethylene-methacrylate.

[0071] The content of the elastomer is preferably 3.5 parts by weight or more relative to 100 parts by weight of the above-mentioned thermoplastic resin. In the past, it was believed that if the content of the elastomer is small, the amount of decomposition gas generated during injection molding is reduced, which is preferred, but the thermoplastic resin composition manufactured by the manufacturing method of the first embodiment is characterized in that by actively releasing low-boiling gases, the MD formed mainly by high-boiling gases can be prevented from adhering to the exhaust holes. Therefore, relative to 100 parts by weight of thermoplastic resin, the content of the elastomer of 3.5 parts by weight or more can be mixed. The upper limit of the content of the elastomer is not particularly limited, and can be set to less than 20 parts by weight, or less than 15 parts by weight, and further less than 13 parts by weight relative to 100 parts by weight of thermoplastic resin. It should be noted that the relationship between the amount of low-boiling gas and high-boiling gas and the formation of MD will be described later.

[0072] The thermoplastic resin composition manufactured by the manufacturing method of the first embodiment contains an antioxidant. The antioxidant refers to an antioxidant substance that has the function of preventing other substances (in the first embodiment, other components other than the antioxidant contained in the thermoplastic resin composition) from being oxidized by itself. The antioxidant includes one selected from the group consisting of phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants. The antioxidant can be used alone or in combination of two or more.

[0073] Phenolic antioxidants are compounds having one or more phenyl groups substituted by hydroxyl groups, preferably phenyl groups substituted by hydroxyl groups and alkyl groups, respectively, in their molecular structures. From the viewpoints of the reduction of MD during injection molding and the gas combustion prevention effect of the injection molded body, as phenolic antioxidants, compounds having phenyl groups substituted by hydroxyl groups and tert-butyl groups are preferred. Among them, compounds having at least one tert-butyl group per phenolic hydroxyl group are preferred. In this case, the phenolic antioxidant is preferably bonded to one or more carbon atoms of the two carbon atoms in the ortho position and the two carbon atoms in the meta position relative to the carbon atom bonded to the phenolic hydroxyl group. In addition, it is more preferred that a tert-butyl group is bonded to at least one of the two carbon atoms in the ortho position relative to the carbon atom bonded to the phenolic hydroxyl group. It is further preferred that a tert-butyl group is bonded to any one of the two carbon atoms in the ortho position relative to the carbon atom bonded to the phenolic hydroxyl group. In addition, a substance having a substituent bonded to one of two carbon atoms ortho to the carbon atom bonded to the phenolic hydroxyl group is called a semi-hindered phenol antioxidant, and a substance having a substituent bonded to two carbon atoms is called a hindered phenol antioxidant.

[0074] 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) benzyl malonate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis[6-(1- 4-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris[ (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 2-octylthio-4,6-bis(4-hydroxy-3,5-di-tert-butyl)phenoxy-1,3,5-triazine, 4,4'-thiobis(6-tert-butyl-m-cresol), triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bisoctylthio-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, 2,2-thiobis(6-tert-butyl-m-cresol) 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenyl isocyanurate, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,4-bis[(octylthio)methyl]-o-cresol, etc.

[0075] Thioether antioxidants that can be used as antioxidants are known to have high antioxidant effects. Examples of thioether antioxidants include tetrakis[methylene-3-(dodecylthio)propionate]methane, dilauryl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0076] On the other hand, phosphorus antioxidants that are known to be useful as antioxidants also have a high antioxidant effect. Examples of phosphorus antioxidants include bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol-diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol-diphosphite, bis(2,4-diisopropylphenyl)pentaerythritol-diphosphite, tris(2,4-di-tert-butylphenyl)phosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-bisphenylene phosphite, distearylpentaerythritol-diphosphite, triphenyl phosphite, and diethyl 3,5-dibutyl-4-hydroxybenzylphosphonate. Among them, in order to reduce the volatilization and decomposition of the antioxidant, an antioxidant with a high melting point is preferred. Specifically, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-diisopropylphenyl)pentaerythritol diphosphite, etc. can be preferably used.

[0077] Examples of the amine antioxidant that can be used in the thermoplastic resin composition produced in the first 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.

[0078] 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, the formation of MD is easily reduced when the thermoplastic resin composition is injection molded, and in particular, the amount of MD attached to the vent hole can be reduced in addition to the MD on the wall surface of the cavity.

[0079] As the antioxidant, a phenolic antioxidant can be used together with a thioether antioxidant, a phosphorus antioxidant, or an amine antioxidant. In this case, the content of the phenolic antioxidant is not particularly limited within the range that does not hinder the purpose of the present invention. Typically, the content of the phenolic antioxidant is preferably set to 70% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more relative to the total mass of the antioxidant.

[0080] The thermoplastic resin composition produced by the production method of the first embodiment may contain, in addition to the above-mentioned components, organic or inorganic fillers, lubricants, nucleating agents, transparent agents, plasticizers, UV inhibitors, UV absorbers, pigments, dyes, flame retardants, antistatic agents, anti-burst agents, heat stabilizers, light stabilizers, colorants, silicone oils, carbon black, mold release agents, crystallization accelerators and other additives, other resins, etc. If necessary, one or more of these additives and resins may be kneaded with the components of the above-mentioned thermoplastic resin composition.

[0081] The method for producing a thermoplastic resin composition of the first embodiment includes a step of mixing a thermoplastic resin, an elastomer, and an antioxidant. The step of mixing a thermoplastic resin, an elastomer, and an antioxidant is not particularly limited as long as the above-mentioned necessary or arbitrary components can be uniformly mixed, and can be appropriately selected from the methods for producing a thermoplastic resin composition known in the past. For example, the following method can be cited: using a melt-kneading device such as a single-screw or twin-screw extruder, melt-kneading and extruding each component, and then processing the obtained resin composition into a desired form such as powder, flakes, pellets, etc.

[0082] In the manufacturing method of the first embodiment, the mold temperature T0°C is 40°C or higher and the injection rate is 10 cm 3 / sec. Among the gases with a boiling point of 0 to 400°C generated during injection molding, the amount of gas with a boiling point lower than (T0+20)°C (low boiling gas) is set as a0.

[0083] The amount of gas having a boiling point of (T0-20)°C or higher (high boiling gas) among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0.

[0084] The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point above -20)°C (high boiling gas after staying) is set as b 10 ,

[0085] (Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 ), preferably the mixing step is carried out in a manner that satisfies the following formulae simultaneously.

[0086] b 10 / b0≤2.5 (i)

[0087] a0>b0 (ii)

[0088] The thermoplastic resin composition manufactured by the manufacturing method of the first embodiment can be molded by injection molding. Here, injection molding refers to one of the molding methods of a resin composition by feeding a molten thermoplastic resin into a mold and cooling it. The injection molding method is performed using an injection molding machine. The thermoplastic resin composition is heated while being transported by an extruder equipped with a barrel and a screw, and injected into a mold at a specified injection rate, and the thermoplastic resin composition is pressed by the mold to be molded into an injection molded body having a specified shape. Here, the injection rate is a value indicating the volume of the molten resin injected per unit time, and the unit is [cm 3 / sec]. For injection molding of the thermoplastic resin composition, molding conditions including barrel temperature, injection speed, injection rate, etc. are not particularly limited, and injection molding can be performed under any molding conditions as long as a desired injection molded body can be obtained.

[0089] For example, when the thermoplastic resin composition manufactured by the manufacturing method of the first embodiment is injection molded, the mold temperature can be set to a temperature above 40°C, that is, T0°C. During injection molding, various decomposition gases may be generated due to the heating of the thermoplastic resin composition. The generated gas is discharged to the outside of the mold through the exhaust holes provided in the mold. The gas discharged in this way can be collected, and its amount and type can be measured and analyzed. For the capture method of the gas generated during injection molding and the analysis of the amount and type of the gas, please refer to the prior art (for example, Japanese Patent Gazette No. 2019-181890). The thermoplastic resin composition manufactured by the manufacturing method of the first embodiment is injected into the mold at an injection rate of, for example, 10 cm 3 / second is injected into the mold, and the total amount of gas with a boiling point of 0 to 400°C generated during injection molding at a mold temperature T0°C of 40°C or more is defined as c0 [μg / 1g of thermoplastic resin composition]. Here, the unit of the total amount of gas with a boiling point of 0 to 400°C generated during injection molding c0 is expressed in μg (microgram) per 1g of thermoplastic resin composition injected into the mold cavity in one shot. The gas with a boiling point of 0 to 400°C generated during injection molding is analyzed, and the amount of gas with a boiling point lower than (T0+20)°C (low boiling gas) in the total amount of gas with a boiling point of 0 to 400°C generated during injection molding is defined as a0 [μg / 1g of thermoplastic resin composition], and the amount of gas with a boiling point of (T0-20)°C or more (high boiling gas) is defined as b0 [μg / 1g of thermoplastic resin composition]. Here, the units of a0 and b0 are the same as those of c0 above, and T0 is a value expressing the mold temperature in Celsius. Gases having a boiling point of greater than (T0-20)°C and less than (T0+20)°C are included in both the above-mentioned b0 and a0. Therefore, the value of a0+b0 is equal to c0, or greater than c0. Of the total amount c0 of gas with a boiling point of 0 to 400°C generated during injection molding, the amount a0 of gas with a boiling point lower than (T0+20)°C and the amount b0 of gas with a boiling point greater than (T0-20)°C can be measured using an analytical device for qualitatively and / or quantitatively analyzing the gas with a boiling point of 0 to 400°C generated during injection molding, such as a gas chromatograph (GC) (specifically, refer to the above-mentioned Japanese Patent Gazette No. 2019-181890).

[0090] On the other hand, the thermoplastic resin composition produced by the production method of the first embodiment is injected into the mold at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 The thermoplastic resin composition was allowed to remain in the mold for 10 minutes, and then heated to a temperature of 40°C or higher. 10 The injection molding is performed at ℃, and the total amount of the gas with a boiling point of 0 to 400℃ generated at this time is defined as c 10 [μg / 1 g of thermoplastic resin composition] Here, the total amount of gas having a boiling point of 0 to 400°C generated during injection molding is c 10 The unit of μg (microgram) represents the amount of gas per 1g of the thermoplastic resin composition injected into the mold cavity in one shot. The gas with a boiling point of 0 to 400°C generated during injection molding is analyzed, and the total amount of gas with a boiling point of 0 to 400°C generated during injection molding (hereinafter referred to as "retention gas") is calculated. 10 Medium, with less than (T 10 The amount of gas with a boiling point of +20)°C (hereinafter referred to as "low-boiling gas after retention") is set to a 10[μg / 1g of thermoplastic resin composition], having (T 10 The amount of gas with a boiling point of -20)°C or higher (hereinafter referred to as "high boiling gas after retention") is defined as b 10 [μg / 1g of thermoplastic resin composition]. 10 and b 10 The unit is the same as the above c 10 Same, T 10 is the value of the mold temperature expressed in Celsius, which is equal to T0 above. 10 -20)℃ and below (T 10 +20)℃ is included in the above b 10 Also included in a 10 Therefore, a 10 +b 10 The value is equal to c 10 , or greater than c 10 .

[0091] When the thermoplastic resin composition produced by the production method of the first embodiment is injection molded under predetermined conditions, it is preferred that the following formulas are satisfied simultaneously, particularly focusing on the amount of low boiling gas to high boiling gas and the ratio of the amount of high boiling gas to high boiling gas after retention.

[0092] b 10 / b0≤2.5 (i)

[0093] a0>b0 (ii)

[0094] The above formula (i) indicates that: at a specified injection rate (10cm 3 / second) when a thermoplastic resin composition is injection molded, the thermoplastic resin composition is allowed to stay in the mold for a predetermined time (10 minutes) at the same mold temperature before injection molding, and the amount of high boiling gas captured in the vent (high boiling gas after staying) is less than the predetermined value when the thermoplastic resin composition is not allowed to stay in the mold and injection molding is performed as usual. It should be noted that the ratio of the above formula (i) is more preferably less than 2.0. In addition, the above formula (ii) means that the amount of low boiling gas is greater than the amount of high boiling gas in the total amount of gas with a boiling point of 0 to 400°C generated during normal injection molding. Among the decomposition gases generated during injection molding, high boiling gas is easy to form MD at the vent, etc. Therefore, efforts have been made in the past to reduce the generation of high boiling gas. That is, if a high-boiling gas (a gas with a high boiling point that forms a gas state only after reaching a high temperature. If cooled from a gas state, the temperature only slightly decreases, and it will condense / solidify even at a relatively high temperature) having a high boiling point among the gas components comes into contact with a mold, etc., the gas is cooled on the spot, so the cooled high-boiling gas adheres to the location and easily forms MD. On the other hand, a low-boiling gas (a gas with a low boiling point that is in a gas state even at a relatively low temperature. Even if cooled from a gas state, it will not condense / solidify until it reaches a relatively low temperature) having a low boiling point will not precipitate as MD even if it comes into contact with a mold, etc., unless it is cooled below the low boiling point, and therefore, it is not easy to adhere to the location. The present inventors have conducted in-depth studies on the analysis of the gas captured in the exhaust hole and the mechanism of MD formation, and found that it is very difficult to completely eliminate the generation of high-boiling gas during injection molding of a thermoplastic resin composition. On the other hand, even if the thermoplastic resin compositions having the same amount of high-boiling gas generation are compared with thermoplastic resin compositions having different amounts of low-boiling gas generation, it is found that the thermoplastic resin composition having a large amount of low-boiling gas generation is less likely to form MD. This is believed to be because the probability of high-boiling gas contacting with a mold or the like is reduced by the low-boiling gas. Furthermore, it was also found that even if the high-boiling gas contacts with the mold or the like, the low-boiling gas can remove the high-boiling gas (i.e., can "wash away" or "blow away") before it forms MD.

[0095] If based on the following formulas:

[0096] b 10 / b0≤2.5 (i)

[0097] a0>b0 (ii)

[0098] Then the above formula (i) means that the gas after the stay may contain a certain degree of high-boiling gas after the stay. If the thermoplastic resin composition is allowed to stay in the mold for a predetermined time, the thermoplastic resin composition heated during the stay is prone to thermal decomposition reaction, so if injection molding is performed afterwards, there is a tendency for the total amount of decomposition gas (gas after the stay) captured in the exhaust hole to increase. However, as described above, the generation of high-boiling gas cannot be completely suppressed during injection molding of the thermoplastic resin composition. The thermoplastic resin composition manufactured by the manufacturing method of the first embodiment is a thermoplastic resin composition having thermal durability such that the generation of high-boiling gas after the stay does not increase sharply even under the condition of staying in the mold for a predetermined time. On the other hand, the above formula (ii) means that the thermoplastic resin composition manufactured by the manufacturing method of the first embodiment generates a low-boiling gas in an amount exceeding the generation of high-boiling gas during normal injection molding, which is very important in exerting the technical effect of the first embodiment. As described above, by making the amount of low-boiling gas generated greater than the amount of high-boiling gas generated, the probability of high-boiling gas contacting the exhaust hole, mold, etc. can be reduced, and the adhesion of the high-boiling gas in contact and the subsequent formation of MD can be prevented. By preventing the formation of MD in the exhaust hole and the resulting clogging of the exhaust hole, the gas combustion on the surface of the injection molded body can be prevented.

[0099] It has been previously believed that when a thermoplastic resin composition containing a thioether antioxidant or a phosphorus antioxidant is injection molded, the thioether antioxidant or the phosphorus antioxidant itself is likely to cause MD formation. This is believed to be because the heat resistance of thioether antioxidants and phosphorus antioxidants is often lower than that of phenolic antioxidants. However, according to the above-mentioned study by the present inventors, if a combination of antioxidants that controls the generation amount of low-boiling gas and high-boiling gas is selected, any antioxidant can be used in the production method of the first embodiment.

[0100] The manufacturing method of the first embodiment has technical significance in selecting and mixing a combination of a thermoplastic resin, an elastomer and an antioxidant in a manner that satisfies the above-mentioned formula (i) and formula (ii) at the same time. In order to suppress the decomposition of an elastomer that is relatively easy to decompose in injection molding using high temperature, it is certainly inappropriate to set the temperature in injection molding to a level that is low enough to damage the fluidity of the thermoplastic resin composition. In addition, reducing the amount of such an elastomer is also inappropriate for obtaining the desired thermoplastic resin composition. As described above, a combination of a thermoplastic resin, an elastomer and an antioxidant can be selected in a manner that increases the amount of low-boiling gas generated in the injection molding of the thermoplastic resin composition as much as possible and suppresses the generation of high-boiling gas. As this method, for example, the gas generated when each component is heated can be analyzed, and a component that generates more low-boiling gas than high-boiling gas can be selected, but it is not effective to randomly analyze a variety of thermoplastic resins, elastomers and antioxidants. If it is a person skilled in the art, by confirming the heat resistance indexes such as the thermal decomposition temperature and boiling point disclosed in the catalog, safety data sheet (SDS) issued by the manufacturer of each component, or estimating its heat resistance from the chemical structure, the range of candidate components can be narrowed down to some extent in advance. In addition, for example, with respect to elastomers, the amount of low-boiling gas can also be inferred from impurities (emulsifiers in emulsion polymerization, etc.) derived from the manufacturing method. The thermoplastic resin composition manufactured using the candidate components selected in this way can be subjected to gas analysis. When injection molding is performed using the thermoplastic resin composition manufactured based on such a technical idea, the formation of MD in the vent can be greatly reduced, so no matter how the mold temperature is, high-quality injection molded bodies with no gas combustion or less gas combustion can be effectively manufactured. That is, if the injection molded body is manufactured using the thermoplastic resin composition manufactured by the manufacturing method of the first embodiment, even if continuous injection molding is performed for a long time, it is not easy to produce gas combustion on the surface of the injection molded body that may be caused by the attachment of MD to the vent. This is considered to be due to the reduction of MD to the vent, so the vent is not easy to narrow or clog. Good gas discharge during injection molding can be easily maintained for a long period of time, and as a result, in addition to preventing gas combustion of the injection molded body, the mold can be less likely to be deteriorated.

[0101] The second embodiment is a method for determining the moldability of a thermoplastic resin composition, the thermoplastic resin composition comprising a thermoplastic resin, an elastomer, and an antioxidant, the thermoplastic resin being one or more selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins. The thermoplastic resin composition for determining the moldability in the second embodiment comprises a thermoplastic resin, an elastomer, and an antioxidant, the thermoplastic resin being one or more selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins, and syndiotactic polystyrene resins. The thermoplastic resin composition for determining the moldability in the second embodiment may comprise the thermoplastic resin, elastomer, and antioxidant described in the first embodiment. Furthermore, in the second embodiment, the thermoplastic resin composition for determining moldability may contain, in addition to the above-mentioned components, additives such as organic or inorganic fillers, lubricants, nucleating agents, transparent agents, plasticizers, UV inhibitors, UV absorbers, pigments, dyes, flame retardants, antistatic agents, anti-burst agents, heat stabilizers, light stabilizers, colorants, silicone oils, carbon black, release agents, crystallization accelerators, and other resins as needed.

[0102] The method for determining the moldability of the thermoplastic resin composition according to the second embodiment comprises the steps of: injecting a molded product into a mold at a mold temperature T0°C or higher and at an injection rate of 10 cm 3 / sec. Among the gases with a boiling point of 0 to 400°C generated during injection molding, the amount of gas with a boiling point lower than (T0+20)°C (low boiling gas) is set as a0.

[0103] The amount of gas having a boiling point of (T0-20)°C or higher (high boiling gas) among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0.

[0104] The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point above -20)°C (high boiling gas after staying) is set as b 10 ,

[0105] (Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 ), when the following formulae are satisfied simultaneously, the moldability of the thermoplastic resin composition is judged to be good.

[0106] b 10 / b0≤2.5 (i)

[0107] a0>b0 (ii)

[0108] In the determination method of the second embodiment, the thermoplastic resin composition is injected at an injection rate of, for example, 10 cm 3 / second is injected into the mold, and the total amount of gas with a boiling point of 0 to 400°C generated during injection molding at a mold temperature T0°C of 40°C or more is defined as c0 [μg / 1g of thermoplastic resin composition]. Here, the unit of the total amount of gas with a boiling point of 0 to 400°C generated during injection molding c0 is expressed in μg (microgram) per 1g of thermoplastic resin composition injected into the mold cavity in one shot. The gas with a boiling point of 0 to 400°C generated during injection molding is analyzed, and the amount of gas with a boiling point lower than (T0+20)°C (low boiling gas) in the total amount of gas with a boiling point of 0 to 400°C generated during injection molding is defined as a0 [μg / 1g of thermoplastic resin composition], and the amount of gas with a boiling point of (T0-20)°C or more (high boiling gas) is defined as b0 [μg / 1g of thermoplastic resin composition]. Here, the units of a0 and b0 are the same as those of c0 above, and T0 is a value expressing the mold temperature in Celsius. Gases having a boiling point of greater than (T0-20)°C and less than (T0+20)°C are included in both the above-mentioned b0 and a0. Therefore, the value of a0+b0 is equal to c0, or greater than c0. Of the total amount c0 of gas with a boiling point of 0 to 400°C generated during injection molding, the amount a0 of gas with a boiling point lower than (T0+20)°C and the amount b0 of gas with a boiling point greater than (T0-20)°C can be measured using an analytical device for qualitatively and / or quantitatively analyzing the gas with a boiling point of 0 to 400°C generated during injection molding, such as a gas chromatograph (GC) (specifically, refer to the above-mentioned Japanese Patent Gazette No. 2019-181890).

[0109] On the other hand, the thermoplastic resin composition is injected at an injection rate of, for example, 10 cm 3 / sec injection to a mold temperature T above 40°C 10 The thermoplastic resin composition was allowed to remain in the mold for 10 minutes, and then heated to a temperature of 40°C or higher. 10 The injection molding is performed at ℃, and the total amount of the gas with a boiling point of 0 to 400℃ generated at this time is defined as c 10 [μg / 1 g of thermoplastic resin composition] Here, the total amount of gas having a boiling point of 0 to 400°C generated during injection molding is c 10 The unit of μg (microgram) is the amount of gas per 1g of the thermoplastic resin composition injected into the mold cavity in one shot. The gas with a boiling point of 0 to 400°C generated during injection molding is analyzed, and the total amount of gas with a boiling point of 0 to 400°C generated during injection molding (retention gas) is calculated. 10 Medium, with less than (T10 +20)℃ boiling point gas (low boiling gas after staying) is set as a 10 [μg / 1g of thermoplastic resin composition], having (T 10 The amount of gas with a boiling point above -20)°C (high boiling gas after staying) is set as b 10 [μg / 1g of thermoplastic resin composition]. 10 and b 10 The unit is the same as the above c 10 Same, T 10 is the value of the mold temperature expressed in Celsius, which is equal to T0 above. 10 -20)℃ and below (T 10 +20)℃ is included in the above b 10 Also included in a 10 Therefore, a 10 +b 10 The value is equal to c 10 , or greater than c 10 .

[0110] When the thermoplastic resin composition is injection molded under predetermined conditions, particularly focusing on the amount of the low boiling gas to the high boiling gas, and the ratio of the amount of the high boiling gas to the amount of the high boiling gas after residence, when the following formulas are satisfied at the same time:

[0111] b 10 / b0≤2.5 (i)

[0112] a0>b0 (ii)

[0113] It can be determined that the thermoplastic resin composition has good moldability. The above formula (i) represents: 3 When the thermoplastic resin composition is injection molded at a temperature of 1000 ℃ and a temperature of 1000 ℃ and a temperature of 2000 ℃ and a temperature of 4000 ℃ and a temperature of 5000 ℃, the thermoplastic resin composition is allowed to stay in the mold for a predetermined time (10 minutes) and then injection molded. The ratio of the amount of high boiling gas captured in the vent (high boiling gas after staying) to the amount of high boiling gas captured in the vent when the thermoplastic resin composition is not allowed to stay in the mold and injection molding is performed as usual is less than a predetermined value. It should be noted that the ratio of the above formula (i) is more preferably less than 2.0. In addition, the above formula (ii) means that the amount of low boiling gas is greater than the amount of high boiling gas in the total amount of gas with a boiling point of 0 to 400° C. generated during normal injection molding.

[0114] The above formula (i) means that the gas after the stay may contain a certain degree of high-boiling gas after the stay. If the thermoplastic resin composition is allowed to stay in the mold for a predetermined time, the thermoplastic resin composition heated during the stay is prone to thermal decomposition reaction, so if injection molding is performed afterwards, there is a tendency for the total amount of decomposition gas (gas after the stay) captured in the exhaust hole to increase. However, as described above, the generation of high-boiling gas cannot be completely suppressed during injection molding of the thermoplastic resin composition. In the determination method of the second embodiment, whether the thermoplastic resin composition has a thermal durability such that the generation of high-boiling gas after the stay does not increase sharply even under the condition of staying in the mold for a predetermined time can be used as a benchmark. On the other hand, the above formula (ii) means that the thermoplastic resin composition generates a low-boiling gas in an amount exceeding the generation of high-boiling gas during normal injection molding. As described above, if the mechanism of suppressing MD formation is considered, that is, by making the amount of low-boiling gas generated greater than the amount of high-boiling gas generated, the probability of high-boiling gas contacting with the vent, mold, etc. can be reduced, and the adhesion of the high-boiling gas in contact and the subsequent formation of MD can be prevented, then the above formula (ii) can also be another reference in the method for determining the moldability of the thermoplastic resin composition. In this way, it is determined in advance whether the above formula (i) and formula (ii) are satisfied at the same time. When both formulas are satisfied at the same time, it can be determined that the thermoplastic resin composition can be well molded. The thermoplastic resin composition determined in this way can prevent the formation of MD in the vent and the resulting clogging of the vent during injection molding, and can prevent gas combustion on the surface of the injection molded body.

[0115] The third embodiment is a thermoplastic resin composition, which includes a thermoplastic resin, an elastomer and an antioxidant, wherein the thermoplastic resin is one or more selected from the group consisting of polyarylene sulfide resin, aromatic polyamide resin and syndiotactic polystyrene resin, and the thermoplastic resin composition is used for molding at a temperature above the decomposition temperature of the elastomer. The thermoplastic resin composition of the third embodiment may include the thermoplastic resin, elastomer and antioxidant described in the first embodiment. Furthermore, in addition to the above-mentioned components, the thermoplastic resin composition of the third embodiment may also include additives such as organic or inorganic fillers, lubricants, nucleating agents, transparent agents, plasticizers, UV inhibitors, UV absorbers, pigments, dyes, flame retardants, antistatic agents, anti-burst agents, heat stabilizers, light stabilizers, colorants, silicone oils, carbon black, release agents, crystallization promoters, and other resins as needed. The thermoplastic resin composition of the third embodiment is used for molding at a temperature above the decomposition temperature of the elastomer contained in the thermoplastic resin composition.

[0116] The thermoplastic resin composition for molding at a temperature higher than the decomposition temperature of the elastomer according to the third embodiment is injected at a mold temperature T0°C higher than 40°C at an injection rate of 10 cm 3 / sec. Among the gases with a boiling point of 0 to 400°C generated during injection molding, the amount of gas with a boiling point lower than (T0+20)°C (low boiling gas) is set as a0.

[0117] The amount of gas having a boiling point of (T0-20)°C or higher (high boiling gas) among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0.

[0118] The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature T above 40°C 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point above -20)°C (high boiling gas after staying) is set as b 10 ,

[0119] (Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 ), and satisfy the following equations.

[0120] b 10 / b0≤2.5 (i)

[0121] a0>b0 (ii)

[0122] The thermoplastic resin composition for molding at a temperature equal to or higher than the decomposition temperature of the elastomer according to the third embodiment is injected at an injection rate of, for example, 10 cm 3 / second is injected into the mold, and the total amount of gas with a boiling point of 0 to 400°C generated during injection molding at a mold temperature T0°C of 40°C or more is defined as c0 [μg / 1g of thermoplastic resin composition]. Here, the unit of the total amount of gas with a boiling point of 0 to 400°C generated during injection molding c0 is expressed in μg (microgram) per 1g of thermoplastic resin composition injected into the mold cavity in one shot. The gas with a boiling point of 0 to 400°C generated during injection molding is analyzed, and the amount of gas with a boiling point lower than (T0+20)°C (low boiling gas) in the total amount of gas with a boiling point of 0 to 400°C generated during injection molding is defined as a0 [μg / 1g of thermoplastic resin composition], and the amount of gas with a boiling point of (T0-20)°C or more (high boiling gas) is defined as b0 [μg / 1g of thermoplastic resin composition]. Here, the units of a0 and b0 are the same as those of c0 above, and T0 is a value expressing the mold temperature in Celsius. Gases having a boiling point of greater than (T0-20)°C and less than (T0+20)°C are included in both the above-mentioned b0 and a0. Therefore, the value of a0+b0 is equal to c0, or greater than c0. Of the total amount c0 of gas with a boiling point of 0 to 400°C generated during injection molding, the amount a0 of gas with a boiling point lower than (T0+20)°C and the amount b0 of gas with a boiling point greater than (T0-20)°C can be measured using an analytical device for qualitatively and / or quantitatively analyzing the gas with a boiling point of 0 to 400°C generated during injection molding, such as a gas chromatograph (GC) (specifically, refer to the above-mentioned Japanese Patent Gazette No. 2019-181890).

[0123] On the other hand, the thermoplastic resin composition is injected at an injection rate of, for example, 10 cm 3 / sec injection to a mold temperature T above 40°C 10 The thermoplastic resin composition was allowed to remain in the mold for 10 minutes, and then heated to a temperature of 40°C or higher. 10 The injection molding is performed at ℃, and the total amount of the gas with a boiling point of 0 to 400℃ generated at this time is defined as c 10 [μg / 1 g of thermoplastic resin composition] Here, the total amount of gas having a boiling point of 0 to 400°C generated during injection molding is c 10 The unit of μg (microgram) is the amount of gas per 1g of the thermoplastic resin composition injected into the mold cavity in one shot. The gas with a boiling point of 0 to 400°C generated during injection molding is analyzed, and the total amount of gas with a boiling point of 0 to 400°C generated during injection molding (retention gas) is calculated. 10 Medium, with less than (T 10 +20)℃ boiling point gas (low boiling gas after staying) is set as a 10 [μg / 1g of thermoplastic resin composition], having (T 10The amount of gas with a boiling point above -20)°C (high boiling gas after staying) is set as b 10 [μg / 1g of thermoplastic resin composition]. 10 and b 10 The unit is the same as the above c 10 Same, T 10 is the value of the mold temperature expressed in Celsius, which is equal to T0 above. 10 -20)℃ and below (T 10 +20)℃ is included in the above b 10 Also included in a 10 Therefore, a 10 +b 10 The value is equal to c 10 , or greater than c 10 .

[0124] When the thermoplastic resin composition is injection molded under predetermined conditions, the following formulas are satisfied at the same time, particularly focusing on the amount of low boiling gas to high boiling gas and the ratio of the amount of high boiling gas to high boiling gas after retention.

[0125] b 10 / b0≤2.5 (i)

[0126] a0>b0 (ii)

[0127] The above formula (i) indicates that: at a specified injection rate (10cm 3 When the thermoplastic resin composition is injection molded at a temperature of 1000 ℃ and a temperature of 1000 ℃ and a temperature of 2000 ℃ and a temperature of 4000 ℃ and a temperature of 5000 ℃, the thermoplastic resin composition is allowed to stay in the mold for a predetermined time (10 minutes) and then injection molded. The ratio of the amount of high boiling gas captured in the vent (high boiling gas after staying) to the amount of high boiling gas captured in the vent when the thermoplastic resin composition is not allowed to stay in the mold and injection molding is performed as usual is less than a predetermined value. It should be noted that the ratio of the above formula (i) is more preferably less than 2.0. In addition, the above formula (ii) means that the amount of low boiling gas is greater than the amount of high boiling gas in the total amount of gas with a boiling point of 0 to 400° C. generated during normal injection molding.

[0128] The above formula (i) means that the gas after the stay may contain a certain degree of high-boiling gas after the stay. If the thermoplastic resin composition is allowed to stay in the mold for a predetermined time, the thermoplastic resin composition heated during the stay is easy to undergo a thermal decomposition reaction. Therefore, if injection molding is performed afterwards, there is a tendency that the total amount of decomposition gas (gas after the stay) captured in the vent increases. However, as described above, the generation of high-boiling gas cannot be completely suppressed during injection molding of the thermoplastic resin composition. In the determination method of the second embodiment, whether the thermoplastic resin composition has a thermal durability such that the amount of high-boiling gas generated after the stay does not increase sharply even under the condition of staying in the mold for a predetermined time can be a benchmark. On the other hand, the above formula (ii) means that the thermoplastic resin composition generates a low-boiling gas in an amount exceeding the amount of high-boiling gas generated during normal injection molding. As described above, by making the amount of low-boiling gas generated more than the amount of high-boiling gas generated, the probability of high-boiling gas contacting with the vent, mold, etc. can be reduced, and the adhesion of the contacted high-boiling gas and the subsequent formation of MD can be prevented, so that the thermoplastic resin composition of the third embodiment can be molded at a temperature above the decomposition temperature of the elastomer. The thermoplastic resin composition of the third embodiment can prevent the formation of MD in vent holes and the clogging of vent holes caused thereby during injection molding, and can prevent combustion of gas on the surface of the injection molded article.

[0129] Example

[0130] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0131] [Preparation of thermoplastic resin composition]

[0132] The following raw material components were dry-blended and then introduced into a twin-screw extruder at a cylinder temperature of 320° C. to perform melt kneading to obtain a pelletized thermoplastic resin composition. The blending amount (parts by mass) of each component is shown in Table 1.

[0133] Thermoplastic resin

[0134] PPS-1: polyphenylene sulfide resin, FORTRON KPS (product name), KUREHA CORPORATION, melt viscosity: 30 Pa·s (shear rate: 1200 / sec, temperature: 310°C)

[0135] PPS-2: polyphenylene sulfide resin, FORTRON KPS (product name), KUREHA CORPORATION, melt viscosity: 130 Pa·s (shear rate: 1200 / sec, temperature: 310°C)

[0136] Elastomer

[0137] PPS-3: polyphenylene sulfide resin, FORTRON KPS (product name), KUREHA CORPORATION, melt viscosity: 20 Pa·s) (shear rate: 1200 / sec, temperature: 310°C)

[0138] Olefin copolymer 1 (elastomer 1): BONDFAST 7L (product name), Sumitomo Chemical Co., Ltd., containing 70 parts by mass of ethylene, 3 parts by mass of glycidyl methacrylate, and 27 parts by mass of methyl acrylate as copolymer components

[0139] Olefin copolymer 2 (elastomer 2): MODIPER A4400 (product name), NOF Corporation, a copolymer obtained by grafting 30 parts by weight of styrene / acrylonitrile copolymer onto 70 parts by weight of ethylene / glycidyl methacrylate copolymer

[0140] Olefin copolymer 3 (elastomer 3): MODIPER A4300 (product name), NOF Corporation, a copolymer obtained by grafting 30 parts by weight of methyl methacrylate / butyl acrylate copolymer onto 70 parts by weight of ethylene / glycidyl methacrylate copolymer

[0141] Antioxidants

[0142] Antioxidant 1: IRGANOX 1010 (product name), BASF Japan Ltd., hindered phenol antioxidant (tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane)

[0143] Antioxidant 2: IRGANOX 245 (product name), BASF Japan Ltd., semi-hindered phenol antioxidant (triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate])

[0144] Antioxidant 3: ADK STAB AO-40 (product name), ADEKA CORPORATION, semi-hindered phenol antioxidant (4,4'-butylidene bis(6-tert-butyl-m-cresol))

[0145] Antioxidant 4: ADK STAB AO-30 (product name), ADEKA CORPORATION, semi-hindered phenol antioxidant (1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane)

[0146] Antioxidant 5: Sumilizer GA-80 (product name), Sumitomo Chemical Co., Ltd., semi-hindered phenol antioxidant (3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane)

[0147] Antioxidant 6: ADK STAB PEP-36 (product name), ADEKA CORPORATION, hindered phenol antioxidant (bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite)

[0148] Antioxidant 7: ADK STAB AO-412S (product name), ADEKA CORPORATION, thioether antioxidant (tetrakis[methylene 3(dodecylthio)propionate]methane)

[0149] Fiberglass

[0150] 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.

[0151] Calcium carbonate: WHITON P-30 (product name), Toyo Fine Chemical CO., LTD.

[0152] [Gas combustion generation evaluation]

[0153] The thermoplastic resin composition prepared above was injected into an injection molding machine (FANUCROBOSHOTS2000i30A, FUNAC Co., Ltd., screw diameter 16 mm) at a barrel temperature of 320° C., a mold temperature of 140° C., an injection speed of 50 mm / sec, an injection time of 2 sec, a cooling time of 10 sec, and an injection rate of 10 cm 3 Injection molding was continuously performed under the condition of 100 mol / s to obtain an injection molded body. In the injection molding machine, a mold having a vent hole having a thickness of 7 μm and a width of 4 mm provided in the vent portion was used.

[0154] Injection molding was continuously performed under the above conditions, and the number of injections at which gas combustion began to occur in the obtained injection molded body was measured. A large number of injections at which gas combustion occurred means that gas combustion is not likely to occur even after the number of injection moldings. On the other hand, a small number of injections at which gas combustion occurred means that gas combustion began to occur in the early stage of continuous injection molding. When the number of injections at which gas combustion occurred exceeded 200, the moldability was judged to be good, and when the number of injections at which gas combustion occurred was less than 200, the moldability was judged to be poor. The evaluation results are shown in Tables 1 and 2.

[0155] [Analysis of Gas Generated During Injection Molding]

[0156] When an injection molded body is obtained according to the method described in the above-mentioned gas combustion occurrence evaluation method, at the stage of injection molding for a predetermined number of times before gas combustion occurs, the gas generated so far is vacuum captured using an exhaust gas capture tube. Through this gas capture method, the gas generated during molding can be recovered almost without omission in a manner without loss caused by adhesion to the mold. The captured gas was analyzed by gas chromatography (GC, using column: Agilent Technologies, Inc. DB5-MS, heating rate 10°C / min) in accordance with the method described in Japanese Patent Gazette No. 2019-181890, and the results were all gases with a boiling point of 0 to 400°C.

[0157] The components with a retention time of less than 16 minutes on the GC chart (components with a boiling point of less than 160°C) are regarded as low boiling gas, and the amount of low boiling gas is calculated from the peak area of ​​the GC chart. On the other hand, the components with a retention time of more than 12 minutes (components with a boiling point of more than 120°C) are regarded as high boiling gas, and the amount of high boiling gas is calculated from the peak area of ​​the GC chart. Finally, c0 [μg / 1g of thermoplastic resin composition] is obtained by dividing the amount of gas captured during a predetermined number of injection moldings by the total weight of the molded body obtained by the predetermined number of injection moldings, a0 [μg / 1g of thermoplastic resin composition] is obtained by dividing the amount of low boiling gas by the total weight of the molded body obtained by the predetermined number of injection moldings, and b0 [μg / 1g of thermoplastic resin composition] is obtained by dividing the amount of high boiling gas by the total weight of the molded body obtained by the predetermined number of injection moldings.

[0158] Furthermore, differently from the above, the thermoplastic resin composition is injected once under the same conditions as above, and the thermoplastic resin composition is allowed to remain in the mold for 10 minutes as it is. Then, the injection molding machine is operated once, and the gas generated during injection molding is vacuum-captured using an exhaust gas capture tube. Through this gas capture method, the gas generated during molding can be recovered almost without omission in a manner without loss caused by adhesion to the mold. The generated gas is analyzed by gas chromatography (GC, using column: Agilent Technologies, Inc. DB5-MS, heating rate 10°C / min). The components with a retention time of less than 16 minutes on the GC chart (components with a boiling point lower than 160°C) are regarded as low-boiling gases after residence, and the amount of low-boiling gases after residence is calculated from the peak area of ​​the GC chart. On the other hand, the components with a retention time of more than 12 minutes (components with a boiling point of more than 120°C) are regarded as high-boiling gases after residence, and the amount of high-boiling gases after residence is calculated from the peak area of ​​the GC chart. Finally, the amount of captured gas is divided by the weight of the injection molded body to obtain c. 10 [μg / 1g of thermoplastic resin composition], the amount of low-boiling gas after retention is divided by the weight of the injection molded body to obtain a 10 [μg / 1g of thermoplastic resin composition], and then the amount of high boiling gas after retention is divided by the weight of the injection molded body to obtain b 10 [μg / 1g of thermoplastic resin composition].

[0159] [Table 1]

[0160]

[0161] [Table 2]

[0162]

[0163] As can be seen from Table 1, the thermoplastic resin compositions of the present invention (Examples 1 to 8) comprising a thermoplastic resin, an elastomer and an antioxidant and satisfying both the above formula (i) and formula (ii) have a large number of gas combustion generation shots and good moldability.

[0164] In addition, the thermoplastic resin compositions of Examples 2 and 4 to 6 in which the semi-hindered phenol antioxidants (antioxidants 2 to 4) were blended generated more low-boiling gas during injection molding, and a tendency to suppress the generation of high-boiling gas was observed, compared with the thermoplastic resin compositions of Examples 1, 3 and 7 in which the hindered phenol antioxidants (antioxidants 1 and 5) were blended, and Example 8 in which the thioether antioxidant (antioxidant 6) was blended. As a result, the number of injections in which gas combustion occurred in the thermoplastic resin compositions of Examples 2 and 4 to 6 increased, and it can be said that the semi-hindered phenol antioxidants contained in the thermoplastic resins of these Examples can more effectively suppress the gas combustion of the thermoplastic resin compositions.

[0165] As shown in Table 2, when the thermoplastic resin composition (Comparative Examples 1 and 2) containing no antioxidant is injection molded, gas combustion occurs earlier. In addition, when the thermoplastic resin composition (Comparative Examples 4, 5, and 6) containing both a thermoplastic resin, an elastomer, and an antioxidant but not satisfying any one of the formula (i) or formula (ii) defined in the present invention, and the thermoplastic resin composition (Comparative Example 3) not satisfying both the formula (i) and the formula (ii) are injection molded, the number of injections in which gas combustion occurs is also small. From Tables 1 and 2, it can be said that whether the above-mentioned formula (i) and formula (ii) are satisfied is well correlated with the size of the number of injections generated by gas combustion. That is, it can be seen that when combining a specific thermoplastic resin, an elastomer, and an antioxidant, it is important to consider whether the above-mentioned formula (i) and formula (ii) are satisfied at the same time in order to obtain a thermoplastic resin composition with excellent injection moldability.

Claims

1. A method for producing a thermoplastic resin composition, wherein: The thermoplastic resin composition comprises a thermoplastic resin, an elastomer and an antioxidant, wherein the thermoplastic resin is one or more selected from the group consisting of polyarylene sulfide resin, aromatic polyamide resin and syndiotactic polystyrene resin, and the method for producing the thermoplastic resin composition comprises the following steps: The thermoplastic resin composition is injected at a mold temperature T0°C above 40°C at an injection rate of 10 cm 3 The amount of gas having a boiling point lower than (T0+20)°C among the gas having a boiling point of 0 to 400°C generated during injection molding at 1000 rpm is defined as a0. The amount of gas having a boiling point of (T0-20)°C or higher among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0. The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature above 40°C T 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point of -20)°C or higher is b 10 , The thermoplastic resin, the elastomer and the antioxidant are mixed in a manner that satisfies the following formulae simultaneously: Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 , b 10 / b0≤2.5 (i) a0>b0 (ii).

2. The method for producing a thermoplastic resin composition according to claim 1, wherein: The antioxidant includes one selected from the group consisting of phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants, and the content of the elastomer is 3.5 parts by weight or more based on 100 parts by weight of the thermoplastic resin.

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

4. The method for producing 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 ortho positions with respect to the carbon atom to which the phenolic hydroxyl group is bonded.

5. A method for determining the moldability of a thermoplastic resin composition, wherein: The thermoplastic resin composition comprises a thermoplastic resin, an elastomer and an antioxidant, wherein the thermoplastic resin is one or more selected from the group consisting of polyarylene sulfide resin, aromatic polyamide resin and syndiotactic polystyrene resin, and in the method for determining the moldability of the thermoplastic resin composition, The thermoplastic resin composition is injected at a mold temperature T0°C above 40°C at an injection rate of 10 cm 3 The amount of gas having a boiling point lower than (T0+20)°C among the gas having a boiling point of 0 to 400°C generated during injection molding at 1000 rpm is defined as a0. The amount of gas having a boiling point of (T0-20)°C or higher among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0. The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature above 40°C T 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point of -20)°C or higher is b 10 , When the following formulae are satisfied simultaneously, the thermoplastic resin composition is judged to have good moldability. Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 , b 10 / b0≤2.5 (i) a0>b0 (ii).

6. The method for determining the moldability of a thermoplastic resin composition according to claim 5, wherein: The antioxidant includes one selected from the group consisting of phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants, and the content of the elastomer is 3.5 parts by weight or more based on 100 parts by weight of the thermoplastic resin.

7. The method for determining the moldability of a thermoplastic resin composition according to claim 5 or 6, wherein: The antioxidant is selected from a phenolic antioxidant or a thioether antioxidant, and the phenolic antioxidant has a tert-butyl group bonded to at least one of two carbon atoms ortho-positioned to the carbon atom to which the phenolic hydroxyl group is bonded.

8. The method for determining the moldability of a thermoplastic resin composition according to claim 7, wherein: The phenolic antioxidant has a tert-butyl group bonded to any one of two carbon atoms at ortho positions with respect to the carbon atom to which the phenolic hydroxyl group is bonded.

9. A thermoplastic resin composition comprising a thermoplastic resin, an elastomer and an antioxidant, wherein the thermoplastic resin is at least one selected from the group consisting of polyarylene sulfide resins, aromatic polyamide resins and syndiotactic polystyrene resins, and the thermoplastic resin composition is used for molding at a temperature not lower than the decomposition temperature of the elastomer. The thermoplastic resin composition is injected at a mold temperature T0°C above 40°C at an injection rate of 10 cm 3The amount of gas having a boiling point lower than (T0+20)°C among the gas having a boiling point of 0 to 400°C generated during injection molding at 1000 rpm is defined as a0. The amount of gas having a boiling point of (T0-20)°C or higher among the gas having a boiling point of 0 to 400°C generated during the injection molding is defined as b0. The thermoplastic resin composition was injected at an injection rate of 10 cm 3 / sec injection to a mold temperature above 40°C T 10 ℃ mold, let it stay for 10 minutes, then injection molding, the gas with a boiling point of 0 to 400 ℃ generated at this time, with (T 10 The amount of gas with a boiling point of -20)°C or higher is b 10 , At the same time, the following conditions must be met: Here, a0, b0 and b 10 The unit is μg / 1g of thermoplastic resin composition, T0=T 10 , b 10 / b0≤2.5 (i) a0>b0 (ii).

10. The thermoplastic resin composition according to claim 9, wherein The antioxidant includes one selected from the group consisting of phenolic antioxidants, thioether antioxidants, phosphorus antioxidants and amine antioxidants, and the content of the elastomer is 3.5 parts by weight or more based on 100 parts by weight of the thermoplastic resin.

11. The thermoplastic resin composition according to claim 9 or 10, wherein The antioxidant is selected from a phenolic antioxidant or a thioether antioxidant, and the phenolic antioxidant has a tert-butyl group bonded to at least one of two carbon atoms ortho-positioned to the carbon atom to which the phenolic hydroxyl group is bonded.

12. The thermoplastic resin composition according to claim 11, wherein The phenolic antioxidant has a tert-butyl group bonded to any one of two carbon atoms at ortho positions with respect to the carbon atom to which the phenolic hydroxyl group is bonded.

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