Styrene-based resin composition and molded body

Abstract

Provided is a styrene-based resin composition capable of simultaneously achieving high flame retardancy, impact resistance, and heat resistance. The present invention provides a styrene-based resin composition comprising a rubber-modified styrene-based resin (A), a polyphenylene ether-based resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E). The styrene-based resin composition contains, with respect to 100 parts by mass of the styrene-based resin composition, 26-45 parts by mass of the polyphenylene ether-based resin (B), 15-30 parts by mass of the aromatic phosphate ester (C), and 0.01-0.10 parts by mass of the silicone oil (E).

Description

Styrene-based resin composition and molded article

[0001] This invention relates to a styrene-based resin composition.

[0002] Styrene resin compositions are used in a wide range of fields, including office automation equipment such as personal computers, printers, and copiers, and home appliances such as televisions, VTRs, and audio equipment. Conventionally, various flame retardants have been proposed to impart flame retardancy to styrene resin compositions, and among them, halogen-containing organic compounds, which are inexpensive and have a good balance of physical properties, have been widely used. However, in recent years, there has been increasing activity, particularly in Europe, to regulate halogen-containing organic compounds, leading to a growing demand for flame-retardant resin compositions that do not contain halogen elements. As an alternative to halogen-based flame retardants, phosphorus-based flame retardants are being considered.

[0003] Patent Document 1 discloses a styrene-based flame-retardant resin composition comprising (A) a rubber-modified styrene resin, (B) a polyphenylene ether resin, (C) a condensed phosphate ester, and (D) talc, characterized in that when the total amount of (A) the rubber-modified styrene resin and (B) the polyphenylene ether resin is 100 parts by mass, (B) the polyphenylene ether resin is 10 to 30 parts by mass, (D) the talc is 0.1 to 10 parts by mass, and the content of the rubbery polymer contained in the styrene-based flame-retardant resin composition is 3.5 to 8.5% by mass.

[0004] Japanese Patent Publication No. 2014-55242

[0005] However, conventional styrene-based resin compositions have found it difficult to simultaneously achieve flame retardancy, impact resistance, and heat resistance.

[0006] This invention has been made in view of these circumstances, and provides a styrene-based resin composition that can simultaneously achieve high levels of flame retardancy, impact resistance, and heat resistance.

[0007] According to the present invention, a styrene resin composition is provided comprising a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E), wherein the styrene resin composition contains 26 to 45 parts by mass of the polyphenylene ether resin (B), 15 to 30 parts by mass of the aromatic phosphate ester (C), and 0.01 to 0.10 parts by mass of the silicone oil (E) per 100 parts by mass of the styrene resin composition.

[0008] Through diligent research, the inventors discovered that by specifying the types and amounts of the constituent components in a conventional styrene-based resin composition as described above, it is possible to simultaneously achieve high levels of flame retardancy, impact resistance, and heat resistance, thus completing the present invention.

[0009] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other. [1] A styrene resin composition comprising a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E), wherein the styrene resin composition comprises 26 to 45 parts by mass of the polyphenylene ether resin (B), 15 to 30 parts by mass of the aromatic phosphate ester (C), and 0.01 to 0.10 parts by mass of the silicone oil (E) per 100 parts by mass of the styrene resin composition. [2] A styrene resin composition comprising a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), and a fluorine-based anti-dripping agent (D), wherein the styrene resin composition contains 26 to 45 parts by mass of the polyphenylene ether resin (B) and 15 to 30 parts by mass of the aromatic phosphate ester (C) per 100 parts by mass of the styrene resin composition, and when a molded article made from the styrene resin composition is analyzed by X-ray fluorescence analysis, the peak intensity based on the Kα line of Si is 3000 to 7000 cps / μA. [3] The styrene resin composition according to [1] or [2], wherein the rubber-modified styrene resin (A) contains rubbery polymer particles including a rubbery polymer, the content of the rubbery polymer relative to 100% by mass of the rubber-modified styrene resin (A) is 10 to 20% by mass, and the median particle size of the rubbery polymer particles is 0.1 to 2.0 μm. [4] The polyphenylene ether resin (B) comprises a polyphenylene ether resin (B-1) having a mass-average molecular weight of 10,000 to 35,000 and a polyphenylene ether resin (B-2) having a mass-average molecular weight of more than 35,000 and 100,000 or less, and the mass ratio M of the polyphenylene ether resin (B-1) to the polyphenylene ether resin (B-2) Ｂ－１ : M Ｂ－２ A styrene-based resin composition according to any one of [1] to [3], wherein the ratio is 1:9 to 9:1. A molded article comprising the styrene-based resin composition according to any one of [5], [1] to [4].

[0010] The styrene-based resin composition according to the present invention can be obtained that simultaneously achieves high levels of flame retardancy, impact resistance, and heat resistance. According to one embodiment of the present invention, a styrene-based resin composition can be obtained that simultaneously achieves high levels of flame retardancy, impact resistance, and heat resistance even with a reduced or absent halogen-based flame retardant content. The styrene-based resin composition according to the present invention can be used as a component requiring high levels of flame retardancy, impact resistance, and heat resistance, taking advantage of its properties. For example, it can be used in applications such as office automation equipment and home appliances.

[0011] Embodiments of the present invention will now be described. The various features shown in the embodiments below can be combined with each other. Furthermore, each feature can constitute an invention independently. In addition, any element not specified in the claims in the embodiments below is an optional element and can be omitted. Any number of zeros (for example, one or two) may be added to the end of the numerical values ​​disclosed in the following description. For example, one or two zeros may be added after "1.4" to make it "1.40" or "1.400".

[0012] 1. First Aspect The styrene-based resin composition relating to the first aspect comprises a rubber-modified styrene-based resin (A), a polyphenylene ether-based resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E). The styrene-based resin composition contains, per 100 parts by mass of the styrene-based resin composition, 26 to 45 parts by mass of the polyphenylene ether-based resin (B), 15 to 30 parts by mass of the aromatic phosphate ester (C), and 0.01 to 0.10 parts by mass of the silicone oil (E). Each component will be described in detail below.

[0013] 1.1 Rubber-Modified Styrene Resin (A) The rubber-modified styrene resin (A) according to the present invention may include a styrene polymer that forms a matrix phase and rubbery polymer particles dispersed in the matrix phase. The rubber-modified styrene resin (A) can be obtained by dissolving a rubber component (rubby polymer) in a raw material monomer containing a styrene monomer, and polymerizing it under stirring using thermal polymerization or a polymerization initiator such as a peroxide. The manufacturing process may be batch polymerization or continuous polymerization. Furthermore, it can be manufactured by known polymerization methods, such as bulk polymerization, bulk-suspension two-stage polymerization, or solution polymerization.

[0014] In preparing a styrene-based resin composition, a rubber-modified styrene-based resin (A) and a rubber-modified styrene-based resin composition containing components added during polymerization of the rubber-modified styrene-based resin (A) and / or other components can also be mixed with other components such as a polyphenylene ether resin (B), an aromatic phosphate ester (C), and a fluorine-based anti-dripping agent (D) to obtain a styrene-based resin composition. The rubber-modified styrene-based resin composition may be mainly composed of the rubber-modified styrene-based resin (A), and may contain 90% by mass or more of the rubber-modified styrene-based resin (A) per 100% by mass of the rubber-modified styrene-based resin composition. The content of the rubber-modified styrene-based resin (A) per 100% by mass of the rubber-modified styrene-based resin composition may be, for example, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, 99.9, or 100% by mass, and may be within the range of any two of the values ​​exemplified here.

[0015] The styrene-based polymer constituting the matrix phase contains styrene-based monomer units. The styrene-based monomers can be aromatic vinyl compound monomers, and are monocyclic or polycyclic aromatic vinyl monomers, such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenylbenzene (α-methylstyrene), isopropenyltoluene, isopropenylethylbenzene The methylstyrene is one or more of the following: isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, etc. Preferably, it is one or more of the following: styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, etc., and styrene is particularly preferred.

[0016] Styrene polymers may also include structures derived from other monomers (vinyl monomers) copolymerizable with styrene monomers. Specifically, examples of other monomers include acrylic acid monomers such as acrylic acid and methacrylic acid, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, acrylic monomers such as butyl acrylate and methyl methacrylate, α,β-ethylene unsaturated carboxylic acids such as maleic anhydride and fumaric acid, and imide monomers such as phenylmaleimide and cyclohexylmaleimide. These monomers can also be copolymerized to the extent that the effects of the present invention are not impaired. The rubber-modified styrene resin may have a styrene monomer unit content of, for example, 70, 75, 80, 85, 90, or 95% by mass of 100% by mass of the rubber-modified styrene resin, and may be within the range of any two of the values ​​exemplified here.

[0017] The rubbery polymer particles dispersed in the matrix phase can be rubbery polymers grafted with styrene monomers (rubbery polymers with styrene monomer units grafted onto them). The styrene monomer units grafted onto the rubbery polymer may be the same as or different from the styrene monomer units that constitute the styrene resin forming the matrix phase.

[0018] The rubbery polymer may be a conjugated diene rubbery polymer. Examples of conjugated diene rubbery polymers include polybutadiene, copolymers of butadiene with copolymerizable styrene or methyl methacrylate, etc., such as styrene-butadiene copolymer, polyisoprene, polychloroprene, styrene-isoprene copolymer, ethylene-propylene rubber, and ethylene-propylene-diene rubber, but polybutadiene is particularly preferred. Polybutadiene may be a high-cis type with a high cis-1,4 structural ratio or a low-cis type with a low cis-1,4 structural ratio, but it is preferable to be a high-cis type with a high cis-1,4 structural ratio, and more preferably with a cis-1,4 structural ratio of 90 mol% or more. Furthermore, these may be partially hydrogenated, and may be used alone or in combination of two or more types. The molecular structure of the copolymer may be random or blocky, and the polymer may have a branched structure.

[0019] The rubber-modified styrene resin may be high-impact polystyrene (HIPS), styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, or methyl methacrylate-butadiene-styrene copolymer, with high-impact polystyrene being particularly preferred.

[0020] <Content of rubbery polymer> The content of rubbery polymer in the rubber-modified styrene resin (A) (and / or rubber-modified styrene resin composition) can be 10 to 20% by mass, and preferably 10 to 15% by mass. The content of rubbery polymer in the rubber-modified styrene resin (and / or rubber-modified styrene resin composition) may be, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by mass, and may be within the range of any two of the values ​​exemplified here. By having the content of rubbery polymer in the rubber-modified styrene resin (and / or rubber-modified styrene resin composition) within the above numerical range, the impact resistance can be further improved. The content of rubbery polymer in the rubber-modified styrene resin (composition) can be analyzed by an appropriate method depending on the type of rubbery polymer. For example, if the rubbery polymer is polybutadiene, the rubber-modified styrene resin (composition) is dissolved in chloroform, a certain amount of iodine monochloride / carbon tetrachloride solution is added, and the mixture is left in the dark for about 1 hour. Then, potassium iodide solution is added, and the excess iodine monochloride is titrated with a 0.1 N sodium thiosulfate / ethanol aqueous solution. The amount of iodine monochloride added can be calculated, and specifically, it can be determined by the method described in the examples.

[0021] <Volume Median Particle Size of Rubber-like Polymer Particles> The volume median particle size of rubber-like polymer particles is preferably 0.1 to 2.0 μm. The volume median particle size of rubber-like polymer particles is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 μm, and may be within the range of any two of the values ​​exemplified here. By having the volume median particle size of rubber-like polymer particles within the above numerical range, the surface gloss of the molded article can be improved. The volume-based median particle size of rubbery polymer particles can be determined as the 50% volume particle size of the volume-based particle size distribution curve obtained by dissolving a rubber-modified styrene resin in dimethylformamide and measuring it using a laser diffraction / scattering particle size distribution analyzer (e.g., LA-960 manufactured by Horiba, Ltd.: relative refractive index 120A000I). Alternatively, the particle size of rubbery polymer particles can be observed and measured using an electron microscope. For example, the particle size can be determined by staining a rubber-modified styrene resin (and / or a rubber-modified styrene resin composition) with osmium tetroxide, taking TEM images of the rubbery dispersed particles in an ultrathin section using a transmission electron microscope (TEM), measuring the diameter of the rubbery dispersed particles, and calculating the particle size as the volume-based median diameter. Specifically, it can be determined by the method described in the examples.

[0022] <Melt Mass Flow Rate (MFR)> The melt mass flow rate (MFR) of rubber-modified styrene resin (A) (and / or rubber-modified styrene resin composition), measured according to JIS K-7210 under conditions of 200°C and a 49N load, can be 1.0 to 15.0 g / 10 min. The MFR can be, for example, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, or 15.0 g / 10 min, and may also be within the range of any two of the values ​​exemplified here. Being within this numerical range allows for fluidity during molding and practical strength to be achieved.

[0023] <Vicat Softening Temperature> The Vicat softening temperature of rubber-modified styrene resin (A) (and / or rubber-modified styrene resin composition), measured according to JIS K-7206 under conditions of a 50N load and a heating rate of 50°C / hr, is preferably 90°C or higher, more preferably 90 to 98°C, and even more preferably 90 to 94°C. The Vicat softening temperature may be, for example, 90, 91, 92, 93, 94, 95, 96, 97, or 98°C, and may be within the range of any two of the values ​​exemplified here. Being within this numerical range provides excellent heat resistance and moldability.

[0024] <Charpy Impact Strength> The Charpy impact strength of a molded article of rubber-modified styrene resin (A) (and / or rubber-modified styrene resin composition) is preferably 5.0 kJ / m ２ That's all. The Charpy impact strengths are, for example, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5, 24.0, 24.5, and 25.0 kJ / m. ２ The value may be within the range of any two of the values ​​exemplified here. The Charpy impact strength can be determined by preparing a test specimen using an injection molding machine and measuring it in accordance with JIS K-7111-1, and specifically by the method described in the examples.

[0025] <Method for producing rubber-modified styrene resin (A) and rubber-modified styrene resin composition> The method for producing rubber-modified styrene resin according to one embodiment of the present invention may include a rubber-modified styrene resin polymerization step in which styrene monomers are graft polymerized in the presence of a rubbery polymer to polymerize the rubber-modified styrene resin. Furthermore, the method for producing rubber-modified styrene resin according to one embodiment of the present invention may include a rubber-modified styrene resin polymerization step in which styrene monomers are graft polymerized in the presence of a rubbery polymer and silicone oil (E) to polymerize the rubber-modified styrene resin.

[0026] Graft polymerization can be carried out by known methods, such as bulk polymerization, suspension polymerization, bulk-suspension two-stage polymerization, and solution polymerization. As solvents, alkylbenzenes such as benzene, toluene, ethylbenzene, and xylene, ketones such as acetone and methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and cyclohexane can be used. Reactor types include fully mixed reactors, plug-flow reactors, and loop reactors that remove a portion of the polymerization solution while polymerization is progressing. A so-called continuous polymerization method, combining these with a volatile matter removal step to remove unreacted monomers, may also be used.

[0027] Examples of rubbery polymers include the rubbery polymers described above. In the graft polymerization process, styrene monomers can also be graft polymerized in the presence of one or more rubbery polymers to synthesize rubber-modified styrene resins.

[0028] In the polymerization process, polymerization solvents, polymerization initiators such as organic peroxides, and chain transfer agents such as aliphatic mercaptans can be used as needed to control the polymerization reaction.

[0029] As the polymerization initiator, radical polymerization initiators are preferable. Examples include peroxyketals such as 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, 2,2-di(4,4-di-t-butylperoxycyclohexyl)propane, and 1,1-di(t-amylperoxy)cyclohexane; hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide; dialkyl peroxides such as t-butyl cumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, and di-t-hexyl peroxide; peroxyesters such as t-butyl peroxyacetate, t-amyl peroxyisononanoate, t-butyl peroxybenzoate, and t-butyl peroxyisopropyl monocarbonate; peroxycarbonates such as t-butyl peroxyisopropyl carbonate and polyether tetrakis(t-butyl peroxycarbonate); and N,N'-azobis(cyclohexane-1-carbonitrile), N,N'-azobis(2-methylbutyronitrile), N,N'-azobis(2,4-dimethylvaleronitrile), N,N'-azobis[2-(hydroxymethyl)propionitrile], etc. One of these or a combination of two or more thereof can be used.

[0030] As the chain transfer agent, either a monofunctional chain transfer agent having one chain transfer group or a polyfunctional chain transfer agent having a plurality of chain transfer groups may be used. Examples of the monofunctional chain transfer agent include aliphatic mercaptans, aromatic mercaptans, pentaphenylethane, α-methylstyrene dimer, terpinolene, etc. Examples of the polyfunctional chain transfer agent include polyfunctional mercaptans obtained by esterifying the hydroxyl groups of polyhydric alcohols such as ethylene glycol, tetraethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and sorbitol with thioglycolic acid or mercaptopropionic acid, etc. One of these or a combination of two or more thereof can be used.

[0031] In the polymerization step, a rubber-modified styrenic resin may be polymerized by graft-polymerizing a styrenic monomer in the presence of a rubber-like polymer and a silicone oil (E). Alternatively, the silicone oil (E) may be added to the rubber-modified styrenic resin composition after polymerization. When preparing the styrenic resin composition, the silicone oil (E) may be added as a part of the components of the rubber-modified styrenic resin composition, or may be added alone as the silicone oil (E). The type and other details of the silicone oil (E) will be described later. In the polymerization step, from the viewpoint of adjusting physical properties, a rubber-modified styrenic resin may be polymerized by graft-polymerizing a styrenic monomer in the presence of a rubber-like polymer and liquid paraffin. Furthermore, from the viewpoint of functioning as a spreading agent, liquid paraffin may be added to the rubber-modified styrenic resin composition after polymerization. When preparing the styrenic resin composition, liquid paraffin may be added as a part of the components of the rubber-modified styrenic resin composition, or may be added alone as liquid paraffin. Any known liquid paraffin (referred to as white oil) that is defined as a mixture of extremely high-purity liquid saturated hydrocarbons belonging to the lubricating oil fraction in terms of boiling point may be used without any problem. The rubber-modified styrenic resin composition comprises the rubber-modified styrenic resin (A), and may optionally contain the above silicone oil (E) and / or liquid paraffin. The content of the silicone oil (E) based on 100% by mass of the rubber-modified styrenic resin composition is, for example, 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5% by mass, and may be within a range between any two of the numerical values exemplified herein. The content of liquid paraffin based on 100% by mass of the rubber-modified styrenic resin composition is, for example, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0% by mass, and may be within a range between any two of the numerical values exemplified herein.

[0032] 1.2 Polyphenylene Ether Resin (B) The polyphenylene ether resin (B) according to the present invention can be a polymer having a repeating unit represented by at least one of general formula (1) and (2) shown below.

[0033]

[0034]

[0035] In formulas (1) and (2), R １ , R ２ , R ３ , R ４ , R ５ , R ６ may each independently represent a C1-C4 alkyl group, an aryl group, halogen, or hydrogen. The number of carbon atoms in the alkyl group is, for example, 1, 2, 3, or 4, and may be within a range between any two of the numerical values exemplified herein. In formula (2), R ５ , R ６ may not both be hydrogen at the same time.

[0036] Representative examples of the polyphenylene ether resin (B) include homopolymers such as poly(2,6-dimethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2-ethyl-6-n-propyl-1,4-phenylene) ether, poly(2,6-di-n-propyl-1,4-phenylene) ether, poly(2-methyl-6-n-butyl-1,4-phenylene) ether, poly(2-ethyl-6-isopropyl-1,4-phenylene) ether, poly(2-methyl-6-chloroethyl-1,4-phenylene) ether, and poly(2-methyl-6-hydroxyethyl-1,4-phenylene) ether. Among these, poly(2,6-dimethyl-1,4-phenylene) ether is particularly preferable. Specific examples of poly(2,6-dimethyl-1,4-phenylene) ether include PPO640 manufactured by SHPP Japan G.K., and PX100F and PX100L manufactured by Global Polyacetal Co., Ltd. These may be used alone, or two or more of these may be used in combination.

[0037] The polyphenylene ether resin (B) preferably has an intrinsic viscosity of 0.25 to 0.50 dl / g, and more preferably 0.30 to 0.40 dl / g. An intrinsic viscosity within the range of 0.25 to 0.50 dl / g is preferable because it provides a good balance between fluidity in the molten state, strength during molding, and flame retardancy.

[0038] The polyphenylene ether resin (B) according to the present invention preferably has a mass-average molecular weight of 10,000 to 100,000, and more preferably 25,000 to 70,000. Having a mass-average molecular weight within this range provides excellent flame retardancy and impact resistance. Furthermore, the polyphenylene ether resin (B) has a number-average molecular weight of, for example, 5,000 to 30,000, and preferably 10,000 to 25,000. The polyphenylene ether resin (B) according to the present invention preferably contains two types of polyphenylene ether resins (B) with different mass-average molecular weights. The polyphenylene ether resin (B) according to the present invention preferably contains a polyphenylene ether resin (B-1) with a mass-average molecular weight of 10,000 to 35,000 and a polyphenylene ether resin (B-2) with a mass-average molecular weight greater than 35,000 and 100,000 or less. The mass-average molecular weight of polyphenylene ether resin (B-1) can be between 10,000 and 35,000. For example, the mass-average molecular weight of polyphenylene ether resin (B-1) may be 10,000, 15,000, 20,000, 25,000, 30,000, or 35,000, and may be within the range of any two of the values ​​exemplified here. The mass-average molecular weight of polyphenylene ether resin (B-2) can be greater than 35,000 and less than or equal to 100,000. The mass-average molecular weight of the polyphenylene ether resin (B-2) is, for example, 36,000, 40,000, 45,000, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000, and 100,000, and may be within the range of any two of the values ​​exemplified herein. The styrene-based resin composition according to the present invention, by containing two types of polyphenylene ether resins (B) with different molecular weights, makes it easier to achieve both higher levels of flame retardancy and impact resistance.

[0039] The mass-average molecular weight (Mw) can be measured using gel permeation chromatography (GPC) under the following conditions: GPC model: Alliance 2695 Waters Column: Shodex GPC LF-804 Mobile phase: Chloroform Sample concentration: Approximately 0.2% by mass Temperature: Oven 40°C Detector: 2998 PDA detector The molecular weight in this invention is calculated by determining the molecular weight at each elution time from the elution curve of monodisperse polystyrene and then calculating the molecular weight in terms of polystyrene.

[0040] The mass of the polyphenylene ether resin (B-1) contained in the styrene resin composition is M. Ｂ－１ The mass of the polyphenylene ether resin (B-2) contained in the styrene resin composition is M Ｂ－２ In this case, the mass ratio M of polyphenylene ether resin (B-1) and polyphenylene ether resin (B-2) Ｂ－１ : M Ｂ－２ However, a ratio of 1:9 to 9:1 is preferable. The mass ratio M of polyphenylene ether resin (B-1) and polyphenylene ether resin (B-2) Ｂ－１ : M Ｂ－２ The ratio can be 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, or 9:1, and may be within the range of any two of the values ​​exemplified here. The styrene-based resin composition according to the present invention easily achieves a higher level of both flame retardancy and impact resistance by containing two types of polyphenylene ether resins (B) with different molecular weights in the above ratios.

[0041] 1.3 Aromatic phosphate ester (C) The aromatic phosphate ester (C) according to the present invention can be a compound represented by the formula (3) shown below.

[0042]

[0043] In equation (3) above, n can be an integer from 1 to 5. n can be, for example, 1, 2, 3, 4, or 5, and may be within the range of any two of the numbers exemplified here. １ ~Ar ４Each of these can independently represent a phenyl group having 6 to 15 carbon atoms or an alkyl-substituted phenyl group. The alkyl substituent (alkyl group) in the alkyl-substituted phenyl group can be, for example, a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group. The alkyl-substituted phenyl group can have, for example, 1 to 5 alkyl groups, preferably 1 to 2. The alkyl-substituted phenyl group can have alkyl groups at the ortho, meta, and para positions relative to the bond position with the oxygen atom, for example, it can have two alkyl groups at the ortho position. The type and number of alkyl substituents in the alkyl-substituted phenyl group are Ar １ ~Ar ４ In each of these, they may be identical or very different from one another. For example, Ar １ ~Ar ４ All of these may be 2,6-dimethylphenyl groups. １ ~Ar ４ X can be either a phenyl group or a 2,6-dimethylphenyl group. X can be one of the following X1, X2, X3, X4, and X5 shown in the formula below.

[0044]

[0045] Examples of aromatic phosphate esters (C) according to the present invention include bisphenol A bis-diphenyl phosphate (C-1) and resorcinol bis-diphenyl phosphate (C-2). Examples of bisphenol A bis-diphenyl phosphate (C-1) include CR-741 manufactured by Daihachi Chemical Industry Co., Ltd. and FP600 manufactured by ADEKA Corporation. Examples of resorcinol bis-diphenyl phosphate (C-2) include CR-733S and PX-200 manufactured by Daihachi Chemical Industry Co., Ltd. It is preferable that the aromatic phosphate ester (C) is liquid at room temperature (23°C). From the viewpoint of excellent hydrolysis resistance and viscosity suitable for handling when transporting liquid at a constant temperature, bisphenol A bis-diphenyl phosphate (C-1) is preferred. By including aromatic phosphate ester (C), flame retardancy can be further improved while maintaining impact resistance.

[0046] 1.4 Fluorine-based anti-dripping agent (D) The fluorine-based anti-dripping agent (D) according to the present invention can be a composition containing a fluorine-containing compound. Examples of fluorine-containing compounds include tetrafluoroethylene copolymers such as polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, and tetrafluoroethylene / hexafluoropropylene copolymer, or polymers obtained by polymerizing (meth)acrylic acid esters, aromatic alkenyl compounds, vinyl cyanide, etc., in the presence of polytetrafluoroethylene, etc., or components (for example, their powders) obtained by compounding a fluorine-based resin with other polymers. Among these, polytetrafluoroethylene (hereinafter sometimes referred to as PTFE) is preferred. These can also be used by dispersing them in a dispersion medium such as water. That is, the fluorine-based anti-dripping agent can be a dispersion liquid obtained by dispersing a fluorine-containing compound in a dispersion medium such as water. When dispersing the fluorine-based anti-dripping agent in a solvent, it is preferable to use it so that the concentration of the fluorine-containing compound is 5 to 60% by mass. The concentration of the fluorine-containing compound may be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60% by mass, and may be within the range of any two of the values ​​exemplified here. By including a fluorine-based anti-dripping agent (D), flame retardancy can be further improved while maintaining impact resistance.

[0047] 1.5 Silicone Oil (E) Examples of the silicone oil (E) according to the present invention include dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, reactive silicone oil, and non-reactive silicone oil, among which dimethyl silicone oil is preferred. The silicone oil (E) preferably has a viscosity of 1 to 100 cs at 25°C. The viscosity of the silicone oil (E) may be, for example, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 cs, and may be within the range of any two of the values ​​exemplified here.

[0048] 1.6 Other styrene resin compositions may contain other components as long as they do not impair the effects of the present invention. For example, a styrene resin composition according to one embodiment of the present invention may contain a styrene resin other than rubber-modified styrene resin (GPPS). In addition, it may also contain rubber in addition to rubber-modified styrene resin. A styrene resin composition according to one embodiment of the present invention may also contain other flame retardants other than the components described above, antioxidants such as phosphorus-based, phenol-based, and amine-based agents, higher fatty acids such as stearic acid, zinc stearate, calcium stearate, and magnesium stearate, and lubricants such as their salts and ethylenebisstearylamide, plasticizers such as liquid paraffin, inorganic fillers such as talc and calcium carbonate, ultraviolet absorbers, antistatic agents, flame retardants, colorants, pigments, deodorants, antibacterial agents, and other additives.

[0049] 1.7 Content of Each Component The styrene-based resin composition according to the present invention may contain a total of 30 to 60 parts by mass of rubber-modified styrene-based resin (A), other styrene-based resins, and other rubbers per 100 parts by mass of the styrene-based resin composition. The total content of rubber-modified styrene-based resin (A), other styrene-based resins, and other rubbers per 100 parts by mass of the styrene-based resin composition may be, for example, 30, 35, 40, 45, 50, 55, or 60 parts by mass, and may be within the range of any two of the values ​​exemplified herein. The styrene-based resin composition according to the present invention may contain 30 to 60 parts by mass of rubber-modified styrene-based resin (A) per 100 parts by mass of the styrene-based resin composition. The content of rubber-modified styrene-based resin (A) per 100 parts by mass of the styrene-based resin composition may be, for example, 30, 35, 40, 45, 50, 55, or 60 parts by mass, and may be within the range of any two of the values ​​exemplified herein. By keeping the content of rubber-modified styrene resin (A) within the above numerical range, it becomes easier to achieve both higher fluidity and impact resistance.

[0050] The styrene-based resin composition according to the present invention contains 26 to 45 parts by mass of polyphenylene ether resin (B) per 100 parts by mass of the styrene-based resin composition. The content of polyphenylene ether resin (B) per 100 parts by mass of the styrene-based resin composition is, for example, 26, 30, 35, 40, or 45 parts by mass, and may be within the range of any two of the values ​​exemplified herein. By setting the content of polyphenylene ether resin (B) within the above numerical range, flame retardancy can be improved while maintaining heat resistance.

[0051] The styrene-based resin composition according to the present invention contains 15 to 30 parts by mass of aromatic phosphate ester (C) per 100 parts by mass of the styrene-based resin composition. The content of aromatic phosphate ester (C) per 100 parts by mass of the styrene-based resin composition is, for example, 15, 20, 25, or 30 parts by mass, and may be within the range of any two of the values ​​exemplified herein. By setting the content of aromatic phosphate ester (C) within the above numerical range, flame retardancy can be improved while maintaining fluidity.

[0052] The styrene-based resin composition according to the present invention can have a polyphenylene ether resin (B) content / aromatic phosphate ester (C) content (mass ratio) of 0.9 to 3.0. The polyphenylene ether resin (B) content / aromatic phosphate ester (C) content (mass ratio) can be, for example, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, and may be within the range of any two of the values ​​exemplified here.

[0053] The styrene-based resin composition according to the present invention contains 0.05 to 3.0 parts by mass of a fluorine-based anti-dripping agent (D) per 100 parts by mass of the styrene-based resin composition. The content of the fluorine-based anti-dripping agent (D) per 100 parts by mass of the styrene-based resin composition may be, for example, 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, or 3.0 parts by mass, and may be within the range of any two of the values ​​exemplified herein. By setting the content of the fluorine-based anti-dripping agent (D) within the above numerical range, flame retardancy can be improved while maintaining cost competitiveness.

[0054] The styrene-based resin composition according to the present invention contains 0.01 to 0.10 parts by mass of silicone oil (E) per 100 parts by mass of the styrene-based resin composition. The content of silicone oil (E) per 100 parts by mass of the styrene-based resin composition is, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, or 0.10 parts by mass, and may be within the range of any two of the values ​​exemplified herein. By setting the content of silicone oil (E) within the above numerical range, impact resistance can be improved while maintaining cost competitiveness.

[0055] The styrene-based resin composition according to the present invention may also contain a halogen-based flame retardant. In the styrene-based resin composition according to one embodiment of the present invention, the content of the halogen-based flame retardant per 100 parts by mass of the styrene-based resin composition may be, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by mass, and may be within the range of any two of the values ​​exemplified herein. The styrene-based resin composition according to one embodiment of the present invention does not have to contain a halogen-based flame retardant, and even with a low content of the halogen-based flame retardant or without it, it is possible to achieve both high flame retardancy and impact resistance.

[0056] 1.8 Physical Properties of Styrene Resin Compositions The styrene resin composition according to one embodiment of the present invention preferably has the following physical properties.

[0057] <Quantitative Evaluation of Si (Silicon) by X-ray Fluorescence Analysis> When a molded article made from a styrene-based resin composition is analyzed by X-ray fluorescence analysis, it is preferable that the peak intensity based on the Kα line of Si is 3000 to 7000 cps / μA. The peak intensity based on the Kα line of Si when a molded article made from a styrene-based resin composition is analyzed by X-ray fluorescence analysis is, for example, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, or 7000 cps / μA, and may be within the range of any two of the values ​​exemplified here. The measurement conditions can be as follows, and can be specifically determined by the method described in the examples. ・Tube voltage: 15kV ・Filter: None ・Measurement time: 100sec ・Irradiation diameter: 7mm By keeping the peak intensity based on the Kα line of Si within the above numerical range, impact resistance can be improved while maintaining cost competitiveness. The peak intensity based on the Si Kα line can be controlled by adjusting the amount of silicone oil (E) contained in the styrene-based resin composition.

[0058] <Flame Retardancy> When a molded article made from the styrene resin composition is subjected to a UL94 combustion test according to the UL94 standard, it is preferable that the flame retardancy is V-0 or V-1. The UL94 combustion test can be performed by the method described in the examples. Flame retardancy can be controlled by highly adjusting the type and amount of styrene resin composition used.

[0059] <Charpy Impact Strength> The Charpy impact strength of a molded article made from the styrene resin composition is preferably 5.5 kJ / m², as measured in accordance with JIS K-7111-1. ２ That's all. The Charpy impact strengths are, for example, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5, 20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5, 24.0, 24.5, and 25.0 kJ / m.２ The value may be within the range of any two of the values ​​exemplified here. The Charpy impact strength can be determined by preparing a test specimen using an injection molding machine and measuring it in accordance with JIS K-7111-1, and specifically by the method described in the examples.

[0060] <Melt Mass Flow Rate (MFR)> The styrene-based resin composition can have a melt mass flow rate (MFR) of 1.0 to 15.0 g / 10 min, measured according to JIS K-7210 under conditions of 200°C and a 49N load. The MFR can be, for example, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, or 15.0 g / 10 min, and may also be within the range of any two of the values ​​exemplified here. Being within this numerical range allows for fluidity during molding and practical strength.

[0061] <Vicat Softening Temperature> The Vicat softening temperature of a styrene-based resin composition, measured according to JIS K-7206 under conditions of a 50N load and a heating rate of 50°C / hr, can be 80 to 90°C. The Vicat softening temperature may be, for example, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90°C, and may also be within the range of any two of the values ​​exemplified here.

[0062] 1.9 Method for Producing a Styrene Resin Composition The method for producing a styrene resin composition according to the present invention is not particularly limited. A method for producing a styrene resin composition according to one embodiment of the present invention may include a mixing step of mixing raw materials containing a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E) to obtain a styrene resin composition. Furthermore, a method for producing a styrene resin composition according to one embodiment of the present invention may include a rubber-modified styrene resin polymerization step of graft polymerizing a styrene monomer in the presence of a rubbery polymer and a silicone oil (E) to polymerize a rubber-modified styrene resin. In this case, the mixing step involves mixing a composition containing a rubber-modified styrene resin (A) and a silicone oil (E) with a polyphenylene ether resin (B), an aromatic phosphate ester (C), and a fluorine-based anti-dripping agent (D). A method for producing a styrene-based resin composition according to another embodiment of the present invention may include a rubber-modified styrene-based resin polymerization step in which a styrene-based monomer is graft polymerized in the presence of a rubber-like polymer to polymerize a rubber-modified styrene-based resin, and in the mixing step, a rubber-modified styrene-based resin (A), a polyphenylene ether-based resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E) may be mixed. That is, the silicone oil (E) may be added in the polymerization step or in the mixing step. Furthermore, the silicone oil (E) may be added in the polymerization step and in the mixing step.

[0063] The method for mixing the resin composition is not particularly limited, and known mixing techniques can be applied. For example, a uniform resin composition can be produced by pre-mixing various raw materials using a mixing device such as a mixer-type mixer, a V-type blender, and a tumbler-type mixer, and then melt-kneading the mixture. The melt-kneading device is also not particularly limited, but examples include a Banbury-type mixer, a kneader, a roll, a single-screw extruder, a special single-screw extruder, and a twin-screw extruder. Furthermore, there is also a method of adding other additives separately during the melt-kneading process using a melt-kneading device such as an extruder.

[0064] 2. Molded Article The molded article according to one embodiment of the present invention is made of the styrene-based resin composition of the present invention described above. The shape and use are not particularly limited, but because the molded article according to the present invention has high flame retardancy, impact resistance and heat resistance, it can be applied to housings, chassis and other parts of large home appliances such as televisions and air conditioners, household electrical appliances such as refrigerator interiors, office automation equipment such as photocopiers, printers, facsimile machines and personal computers, and office equipment.

[0065] <Method for manufacturing molded products> There are no particular limitations on the method for obtaining molded products, but known molding methods such as extrusion molding, injection molding, injection hollow molding, and foam molding can be applied, and molding methods that combine various molding technologies are also acceptable. Furthermore, methods of forming into sheets or films using a T-die sheet extruder, a biaxial stretching machine, and an inflation machine can also be applied. Injection molding is preferred as a method for obtaining molded products.

[0066] 3. Second viewpoint The styrene resin composition relating to the second viewpoint is a styrene resin composition comprising a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), and a fluorine-based anti-dripping agent (D), wherein the styrene resin composition contains 26 to 45 parts by mass of the polyphenylene ether resin (B) and 15 to 30 parts by mass of the aromatic phosphate ester (C) per 100 parts by mass of the styrene resin composition, and when a molded article made from the styrene resin composition is analyzed by X-ray fluorescence analysis, the peak intensity based on the Si Kα line is 3000 to 7000 cps / μA. The differences from the first viewpoint will be explained below.

[0067] The types of rubber-modified styrene resin (A), polyphenylene ether resin (B), aromatic phosphate ester (C), fluorine-based anti-dripping agent (D), silicone oil (E), and other components may be as described in sections 1.1 to 1.6 above.

[0068] 3.1 Content of Each Component The content of rubber-modified styrene resin (A), polyphenylene ether resin (B), aromatic phosphate ester (C), and fluorine-based anti-dripping agent (D) can be as described in 1.7 above. The styrene resin composition according to the present invention may contain 0.01 to 0.10 parts by mass of silicone oil (E) per 100 parts by mass of the styrene resin composition. The content of silicone oil (E) per 100 parts by mass of the styrene resin composition is, for example, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.10 parts by mass, and may be within the range of any two of the values ​​exemplified here. By setting the content of silicone oil (E) within the above numerical range, impact resistance can be improved while maintaining cost competitiveness.

[0069] 3.2 Physical Properties of Styrene-Based Resin Compositions <Quantitative Evaluation of Si (Silicon) by X-ray Fluorescence Analysis> When a molded body made of the styrene-based resin composition is analyzed by X-ray fluorescence analysis, the peak intensity based on the Kα rays of Si is 3000 to 7000 cps / μA. The peak intensity based on the Kα rays of Si when a molded body made of the styrene-based resin composition is analyzed by X-ray fluorescence analysis is, for example, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, or 7000 cps / μA, and may be within the range of any two of the values ​​exemplified here. The measurement conditions can be as follows, and can be specifically determined by the method described in the examples. ・Tube voltage: 15kV ・Filter: None ・Measurement time: 100sec ・Irradiation diameter: 7mm By keeping the peak intensity based on the Kα rays of Si within the above numerical range, flame retardancy can be improved while maintaining impact resistance. The peak intensity based on the Kα radiation of Si can be controlled by adjusting the amount of Si-containing components, such as silicone oil (E), contained in the styrene-based resin composition.

[0070] The physical properties of other styrene-based resin compositions may be the same as those described in 1.8 above. The methods for producing styrene-based resin compositions, molded articles, and methods for producing them may be the same as those described in 1.9 and 2. above.

[0071] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0072] (Example 1) The materials used in the example and comparative example are as follows.

[0073] [Rubber-Modified Styrene Resin (A)] Rubber-modified styrene resin composition (1): Contains HIPS1 (rubber-modified styrene resin (A-1), polystyrene resin modified with polybutadiene rubber, low-sys) Rubber-modified styrene resin composition (2): Contains HIPS2 (rubber-modified styrene resin (A-2), polystyrene resin modified with polybutadiene rubber, low-sys) Rubber-modified styrene resin composition (3): Contains HIPS3 (rubber-modified styrene resin (A-3), polystyrene resin modified with polybutadiene rubber, high-sys) Table 1 shows the characteristics of rubber-modified styrene resin compositions 1 to 3. Each rubber-modified styrene resin composition consists of rubber-modified styrene resin, liquid paraffin, and silicone oil.

[0074]

[0075] <Content of rubbery polymer> The content of rubbery polymer (polybutadiene) in the rubber-modified styrene resin composition was calculated by dissolving the rubber-modified styrene resin composition in chloroform, adding a certain amount of iodine monochloride / carbon tetrachloride solution, leaving it in the dark for about 1 hour, then adding potassium iodide solution, titrating the excess iodine monochloride with a 0.1 N sodium thiosulfate / ethanol aqueous solution, and calculating the amount of iodine monochloride added.

[0076] <Volume Median Particle Size of Rubber-like Polymer Particles> (Laser Diffraction / Scattering Method) The volume median particle size of rubber-like polymer particles was calculated based on the 50% diameter of the volume integrated particle distribution curve. The volume integrated particle distribution curve was obtained by dissolving a rubber-modified styrene resin in dimethylformamide and measuring it using a laser diffraction / scattering particle size distribution analyzer (LA-960, Horiba, Ltd.: relative refractive index 120A000I). The 50% volume particle size of the volume-based particle size distribution curve obtained in this way was taken as the volume median particle size. (Transmission Electron Microscope (TEM) Observation Method) Measurements were also performed using the transmission electron microscope (TEM) observation method. The rubber-modified styrene resin composition was stained with osmium tetroxide, and TEM images of rubber-like dispersed particles in ultrathin sections were taken using a transmission electron microscope (TEM). The diameter of the rubber-like dispersed particles was measured and the particle size was calculated as the volume-based median diameter. The median particle size by volume obtained using the TEM method was 0.6 μm for HIPS1, 2.5 μm for HIPS2, and 2.9 μm for HIPS3.

[0077] <Charpy Impact Strength> Rubber-modified styrene resin was molded into Type A test specimens (dumbbells) as described in JIS K-7139 using an injection molding machine (manufactured by Japan Steel Works, Ltd., J100E-P) at a cylinder temperature of 220°C and a mold temperature of 45°C. A test specimen was cut from the center of the dumbbell and a notch (Type A, r=0.25 mm) was made by cutting. The Charpy impact strength was measured in accordance with JIS K-7111-1.

[0078] <Melt Mass Flow Rate (MFR)> The melt mass flow rate of rubber-modified styrene resin was measured according to JIS K-7210 under conditions of 200°C and a 49N load.

[0079] <Vicat softening temperature> The Vicat softening temperature of rubber-modified styrene resin was measured in accordance with JIS K-7206 under conditions of a 50N load and a heating rate of 50°C / hr.

[0080] The liquid paraffin and silicone oil content was calculated based on the amount added.

[0081] [Polyphenylene ether resin (B)] Polyphenylene ether resin (B-1): Manufactured by Global Polyacetal, PX100F, mass-average molecular weight 3.0 × 10 ４ g / mol Polyphenylene ether resin (B-2): Manufactured by Global Polyacetal, PX100L, mass-average molecular weight 3.8 × 10⁻⁶ ４ The polyphenylene ether resin (B-1) and polyphenylene ether resin (B-2) are both poly(2,6-dimethyl-1,4-phenylene) ethers containing the following structural units. The mass-average molecular weight (Mw) of the polyphenylene ether resin (B) was measured using gel permeation chromatography (GPC) under the following conditions: GPC model: Alliance 2695 Waters Column: Shodex GPC LF-804 Mobile phase: Chloroform Sample concentration: Approximately 0.2% by mass Temperature: Oven 40°C Detector: 2998 PDA detector The mass-average molecular weight was calculated by determining the molecular weight at each elution time from the elution curve of monodisperse polystyrene and then calculating the molecular weight in polystyrene equivalent.

[0082] [Aromatic Phosphate Ester (C)] Aromatic phosphate ester (C-1): Manufactured by ADEKA Corporation, FP600, liquid at room temperature (23°C), having the following structure (in the following formula, n = 1 to 4)

[0083]

[0084] Aromatic phosphate ester (C-2): Manufactured by Daihachi Chemical Industry Co., Ltd., PX-200, powdery at room temperature (23°C), having the following structure

[0085]

[0086] [Fluorine-based anti-dropping agent (D)] Fluorine-based anti-dropping agent (D-1): Manufactured by Mitsui Chemours Fluoroproducts, 31-JR, PTFE (polytetrafluoroethylene)

[0087] [Silicone Oil (E)] Silicone Oil (E-1): Manufactured by Shin-Etsu Chemical Co., Ltd., KF96-10CS, General name: Dimethylpolysiloxane, Viscosity at 25°C: 10 mm ２ / s(cs)

[0088] (Examples 1-7, Comparative Examples 1-6) Rubber-modified styrene resin composition, polyphenylene ether resin (B), aromatic phosphate ester (C), and fluorine-based anti-dripping agent (D) were pre-mixed in the amounts shown in Tables 2 and 3 using a Henschel mixer (Mitsui Miike Chemical Co., Ltd., FM20B), supplied to a twin-screw extruder (Toshiba Machine Co., Ltd., TEM26SS) to form strands, which were then water-cooled and fed to a pelletizer for pelletization. The operating conditions were as follows: Cylinder setting temperature: 190°C (conveying section) to 280°C (mixing to metering section) Screw rotation speed: 900 rpm Extrusion speed: 30 kg / h Resin temperature: 280-290°C Note that silicone oil (E) is included in the rubber-modified styrene resin composition. Also, rubber-modified styrene resin compositions (1) and (2) contain liquid paraffin. Furthermore, the amount (content) of the rubber-modified styrene resin composition in each example includes styrene resins that may be produced as by-products during the polymerization of rubber-modified styrene resin (A). Here, since the content of the by-products can be considered to be trace amounts, the content of rubber-modified styrene resin (A) can be considered to be substantially the amount (content) of the rubber-modified styrene resin composition minus the content of liquid paraffin and silicone oil. That is, rubber-modified styrene resin composition (1) contains 0.6% by mass of liquid paraffin, 0.1% by mass of silicone oil, and 99.3% by mass of rubber-modified styrene resin (A-1) in 100% by mass of rubber-modified styrene resin composition (1). In Example 1, the amount of rubber-modified styrene resin (A-1) is substantially 39.2 parts by mass.

[0089] The obtained styrene-based resin composition was evaluated by the following method. <Quantitative evaluation of Si (silicon) by X-ray fluorescence analysis> A 4 mm thick test piece was prepared by injection molding of pellets of the obtained styrene-based resin composition and subjected to X-ray fluorescence analysis. The measurement conditions are as follows: ・Apparatus: MESA-50, Horiba, Ltd. ・Tube voltage: 15 kV ・Filter: None ・Measurement time: 100 sec ・Irradiation diameter: 7 mm Analysis of the styrene-based resin composition according to Example 4 revealed that the peak intensity based on the Kα rays of Si was 5592 cps / μA.

[0090] <Flame Retardancy> A UL94 combustion test was conducted in accordance with the UL94 standard. First, a combustion test specimen measuring 127 x 12.7 x 2.0 mm was molded using an injection molding machine (manufactured by Japan Steel Works, Ltd., J100E-P). The combustion test was conducted in accordance with the vertical combustion test method (UL94) of Subject 94 from Underwriters Laboratories, Inc. Flame retardancy was evaluated as V-0, V-1, V-2, or NG (less than V-2) according to UL94.

[0091] <Charpy Impact Strength> The obtained pellets were molded into Type A test specimens (dumbbells) as described in JIS K-7139 using an injection molding machine (manufactured by Japan Steel Works, Ltd., J100E-P) at a cylinder temperature of 220°C and a mold temperature of 45°C. A test specimen was cut from the center of the dumbbell specimen and a notch (Type A, r=0.25 mm) was made by cutting. The Charpy impact strength was measured in accordance with JIS K-7111-1.

[0092] <Melt Mass Flow Rate (MFR)> The obtained pellets were measured according to JIS K-7210 under conditions of 200°C and a 49N load.

[0093] <Vicat softening temperature> The Vicat softening temperature of the obtained pellets was measured in accordance with JIS K-7206 under conditions of a 50N load and a heating rate of 50°C / hr.

[0094]

[0095]

Claims

1. A styrene resin composition comprising a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), a fluorine-based anti-dripping agent (D), and a silicone oil (E), wherein the styrene resin composition contains, per 100 parts by mass, 26 to 45 parts by mass of the polyphenylene ether resin (B), 15 to 30 parts by mass of the aromatic phosphate ester (C), and 0.01 to 0.10 parts by mass of the silicone oil (E).

2. A styrene resin composition comprising a rubber-modified styrene resin (A), a polyphenylene ether resin (B), an aromatic phosphate ester (C), and a fluorine-based anti-dripping agent (D), wherein the styrene resin composition contains 26 to 45 parts by mass of the polyphenylene ether resin (B) and 15 to 30 parts by mass of the aromatic phosphate ester (C) per 100 parts by mass of the styrene resin composition, and when a molded article made from the styrene resin composition is analyzed by X-ray fluorescence analysis, the peak intensity based on the Si Kα ray is 3000 to 7000 cps / μA.

3. The styrene resin composition according to claim 1 or claim 2, wherein the rubber-modified styrene resin (A) contains rubbery polymer particles, the content of the rubbery polymer is 10 to 20% by mass relative to 100% by mass of the rubber-modified styrene resin (A), and the median particle size of the rubbery polymer particles is 0.1 to 2.0 μm.

4. The polyphenylene ether resin (B) comprises a polyphenylene ether resin (B-1) having a mass-average molecular weight of 10,000 to 35,000 and a polyphenylene ether resin (B-2) having a mass-average molecular weight of more than 35,000 and 100,000 or less, and the mass ratio M of the polyphenylene ether resin (B-1) to the polyphenylene ether resin (B-2) Ｂ－１ : M Ｂ－２ The styrene-based resin composition according to claim 1 or claim 2, wherein the ratio is 1:9 to 9:

1.

5. A molded article comprising the styrene-based resin composition according to claim 1 or claim 2.

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