Flame-retardant styrene-based resin composition and molded article

Abstract

To provide a flame-retardant styrene-based resin composition that exhibits high flame retardancy and is excellent in light fastness and low dielectricity, and a molding comprising the flame-retardant styrene-based resin composition.SOLUTION: The flame-retardant styrene-based resin composition contains (A) 67.0-98.8 mass% of a styrene-based resin, (B) 1.0-30.0 mass% of phosphinates represented by general formula (1) or (2), and (C) 0.2-3.0 mass% of a hindered amine-based compound. The molding comprises the flame-retardant styrene-based resin composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a flame-retardant styrenic resin composition and a molded article comprising the flame-retardant styrenic resin composition. [Background technology]

[0002] Styrene-based resins are used in a wide range of applications due to their excellent moldability, dimensional stability, and impact resistance. Among them, polystyrene-based resin compositions that have been given flame retardancy are used in a wide range of applications, including home appliances and office automation equipment, and are used for components that require design, such as exterior parts and transparent parts.

[0003] Conventionally, various flame retardants that impart flame retardancy to styrene resins have been proposed, and among them, bromine-based flame retardants that are inexpensive and have a good balance of physical properties are widely used. However, due to the recent trend of regulating halogen-containing organic compounds, mainly in Europe, there is an increasing demand for flame-retardant resins or flame-retardant resin compositions that do not contain bromine elements.

[0004] As an alternative flame retardant to such bromine-based flame retardants, for example, Patent Document 1 discloses a technology relating to a thermoplastic polymer composition in which a phosphinate is added to a thermoplastic polymer, and Patent Document 2 discloses a technology in which a phosphinate is added to polyphenylene ether and polystyrene. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-124466 [Patent Document 2] JP 2008-37970 A Summary of the Invention [Problem to be solved by the invention]

[0006] Although the above-mentioned Patent Document 1 describes imparting flame retardancy to polystyrene, the technology of Patent Document 1 has problems such as a large amount of flame retardant added, which reduces the impact strength of the entire thermoplastic polymer composition or causes poor appearance of molded products formed from the composition. In addition, the technology described in Patent Document 2 contains polyphenylene ether, and therefore has excellent flame retardancy, but has problems with light resistance such as discoloration due to light. Therefore, there is a problem that it is difficult to use for housings of office automation equipment or home appliances.

[0007] Therefore, an object of the present invention is to provide a flame-retardant styrene-based resin composition which exhibits high flame retardancy, and is excellent in low dielectric properties and light resistance, and a molded article containing the flame-retardant styrene-based resin composition. [Means for solving the problem]

[0008] Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems and have found that a flame-retardant styrene-based resin composition exhibiting high flame retardancy, low dielectric properties and excellent light resistance can be obtained by adding a phosphinic acid salt and a hindered amine-based compound in a specific ratio to a styrene-based resin, thereby completing the present invention.

[0009] That is, the present invention is as follows. [1] 67.0 to 98.8% by mass of a styrene-based resin (A), A flame retardant (B) containing at least one phosphinate selected from the group consisting of a phosphinate represented by the following general formula (1) and a diphosphinate represented by the following general formula (2), and [ka] [In the above general formula (1), R 11 and R 12 are each independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; M 1is at least one selected from the group consisting of calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion, and protonated nitrogen base; a is 1 represents an ionic valence, and is an integer of 1 to 3; m 1 is an integer between 1 and 3; a=m 1 R 11 and R 12 If there are multiple of each, 11 and R 12 may be the same or different.] The following general formula (2): [ka] [In the above general formula (2), R 21 and R 22 are each independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; L 23 is a linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 6 to 10 carbon atoms, or an arylalkylene group having 6 to 10 carbon atoms; M 2 is at least one selected from the group consisting of calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion, and protonated nitrogen base; b is M 2 represents an ionic valence, and is an integer of 1 to 3; m 2 is an integer from 1 to 3; i is an integer of 1 or 2; b×i=2m 2 R 21 and R 22 If there are multiple of each, 21 and R 22 may be the same or different.] A flame-retardant styrene-based resin composition comprising: 0.2 to 3.0% by mass of a hindered amine-based compound (C).

[0010] [2] The flame-retardant styrene-based resin composition according to the above [1], wherein the hindered amine compound (C) is a NOR type hindered amine.

[0011] [3] A molded article comprising the flame-retardant styrene-based resin composition according to any one of [1] and [2] above. Effect of the Invention

[0012] According to the present invention, it is possible to provide a flame-retardant styrene-based resin composition which exhibits high flame retardancy, low dielectric properties and excellent light resistance, and a molded article containing the flame-retardant styrene-based resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The following describes in detail an embodiment of the present invention (hereinafter referred to as the "present embodiment"); however, the present invention is not limited to the following description and can be implemented in various modified forms within the scope of its gist.

[0014] [Flame-retardant styrene-based resin composition] The flame-retardant styrene-based resin composition of the present embodiment is characterized by containing 67.0 to 98.8 mass% of a styrene-based resin (A) (hereinafter also referred to as component (A)), 1.0 to 30.0 mass% of a flame retardant (B) (hereinafter also referred to as component (B)) containing a phosphinate, and 0.2 to 3.0 mass% of a hindered amine-based compound (C) (hereinafter also referred to as component (C)). This makes it possible to obtain a flame-retardant styrene-based resin composition which has extremely improved flame retardancy, low dielectric properties and excellent light resistance.

[0015] <Styrene-based resin (A): Component (A)> In the flame-retardant styrene-based resin composition of the present embodiment, the content of the styrene-based resin (A) is 67.0 to 98.8 mass%, preferably 85 to 97 mass%, and more preferably 90 to 96 mass%, relative to 100 mass% of the total amount of the (A), (B) and (C) components. If the content of the styrene-based resin (A) is less than 67.0 mass% or exceeds 98.8 mass%, the flame retardancy decreases.

[0016] The styrene-based resin (A) that can be used in this embodiment is preferably a resin obtained by polymerizing a styrene-based monomer and, if necessary, one or more selected from other vinyl-based monomers copolymerizable with the styrene-based monomer and rubber-like polymer (a). In other words, the styrene-based resin (A) is preferably a polymer having a styrene-based monomer unit, and more preferably a polymer that essentially contains a styrene-based monomer unit and has, as an optional component, other vinyl-based monomers copolymerizable with the styrene-based monomer unit and / or monomer units of rubber-like polymer (a). The preferred form of the styrene resin (A) in this embodiment is not particularly limited, but specifically includes, for example, a rubber-modified styrene resin in which particles of a rubber-like polymer (a) are dispersed in a polymer matrix containing polystyrene, a polystyrene polymer (polystyrene and / or a polystyrene-unsaturated carboxylic acid polymer, etc.), or a styrene copolymer resin. In addition, a styrene polymer having a syndiotactic structure can also be used as the styrene resin (A).

[0017] <<Polystyrene>> In this embodiment, polystyrene is a homopolymer obtained by polymerizing a styrene-based monomer, and generally available ones can be appropriately selected and used. In addition to styrene, the styrene-based monomer constituting polystyrene includes α-methylstyrene, α-methyl-p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, and t-butylstyrene, or styrene derivatives such as bromostyrene and indene. Styrene is particularly preferred from an industrial viewpoint. One or more of these styrene-based monomers can be used. Polystyrene typically consists of styrene-based monomer units, although it is not excluded that polystyrene further contains monomer units other than the above-mentioned styrene-based monomer units within a range that does not impair the effects of the present invention.

[0018] <<Rubber-modified styrene resin>> In this embodiment, the rubber-modified styrene-based resin is a resin in which particles of a rubber-like polymer (a) are dispersed in a styrene-based resin as a matrix, and can be produced by polymerizing a styrene-based monomer in the presence of the rubber-like polymer (a).

[0019] Examples of the styrene monomer constituting the rubber-modified styrene resin of the present embodiment include, in addition to styrene, α-methylstyrene, α-methyl p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, and t-butylstyrene, or styrene derivatives such as bromostyrene and indene. Styrene is particularly preferred. These styrene monomers can be used alone or in combination.

[0020] The rubber-like polymer (a) contained in the rubber-modified styrene-based resin of this embodiment may, for example, contain a resin containing a styrene monomer unit obtained from the above-mentioned styrene-based monomer inside the rubber-like polymer (a), and / or may be a rubber-like polymer (a) having a resin containing a styrene monomer unit grafted onto the surface thereof.

[0021] As the rubber-like polymer (a), for example, a rubber component such as polybutadiene, polyisoprene, natural rubber, polychloroprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, etc. can be used. The rubber component may also include a form containing polystyrene and / or polystyrene-unsaturated carboxylic acid polymer. Among them, the rubber-like polymer (a) is preferably polybutadiene or styrene-butadiene copolymer. As the polybutadiene, both high-cis polybutadiene having a high cis content and low-cis polybutadiene having a low cis content can be used. In addition, both random structure and block structure can be used as the structure of the styrene-butadiene copolymer. These rubber-like polymers (a) can be used alone or in combination. In addition, saturated rubber obtained by hydrogenating butadiene rubber can also be used.

[0022] Examples of such rubber-modified styrene-based resins include HIPS (high impact polystyrene), ABS resin (acrylonitrile-butadiene-styrene copolymer), AAS resin (acrylonitrile-acrylic rubber-styrene copolymer), and AES resin (acrylonitrile-ethylene propylene rubber-styrene copolymer).

[0023] When the rubber-modified styrene resin is a HIPS resin, the particularly preferred rubber polymer (a) is a high-cis polybutadiene having 90 mol % or more of cis-1,4 bonds. In the high-cis polybutadiene, the vinyl 1,2 bonds are preferably 6 mol % or less, and more preferably 3 mol % or less.

[0024] The content of isomers having a cis-1,4 structure, a trans-1,4 structure, or a vinyl-1,2 structure as the structural unit of the isomeric polybutadiene can be measured using an infrared spectrophotometer and calculated by processing the data using the Morello method.

[0025] The high-cis polybutadiene can be easily obtained by a known production method, for example, by polymerizing 1,3-butadiene using a catalyst containing an organoaluminum compound and a cobalt or nickel compound.

[0026] The content of the rubber-like polymer (a) in the rubber-modified styrene-based resin is preferably 3 to 20 mass%, more preferably 5 to 15 mass%, based on 100 mass% of the total amount of the rubber-modified styrene-based resin. If the content of the rubber-like polymer (a) is less than 3 mass%, the impact resistance of the styrene-based resin may decrease. If the content of the rubber-like polymer (a) is more than 20 mass%, the flame retardancy may decrease.

[0027] In the present disclosure, the content of the rubber-like polymer (a) contained in the rubber-modified styrene-based resin is a value calculated using pyrolysis gas chromatography.

[0028] The average particle size of the rubber-like polymer (a) contained in the rubber-modified styrene-based resin is preferably 0.5 to 4.0 μm, and more preferably 0.8 to 3.5 μm, from the viewpoints of impact resistance and flame retardancy.

[0029] In the present disclosure, the average particle size of the rubber-like polymer (a) contained in the rubber-modified styrene-based resin can be measured by the following method. A 75 nm thick ultrathin section is prepared from the rubber-modified styrene-based resin stained with osmium tetroxide, and a photograph is taken at a magnification of 10,000 times using an electron microscope. In the photograph, the black-stained particles are the rubber-like polymer (a). From the photograph, the following formula (N1): Average particle diameter=ΣniDri 3 / ΣniDri 2 (N1) (In the above formula (N1), ni is the number of rubber polymer (a) particles having a particle diameter Dri, and the particle diameter Dri is the particle diameter calculated as a circle-equivalent diameter from the area of ​​the particle in the photograph.) The area-average particle size is calculated by the above formula, and is regarded as the average particle size of the rubber-like polymer (a). In this measurement, a photograph is scanned at a resolution of 200 dpi, and the measurement is performed using particle analysis software of an image analyzer IP-1000 (manufactured by Asahi Kasei Corporation).

[0030] The reduced viscosity of the rubber-modified styrene-based resin (which is an index of the molecular weight of the rubber-modified styrene-based resin) is preferably in the range of 0.50 to 0.85 dL / g, more preferably in the range of 0.55 to 0.80 dL / g. If it is less than 0.50 dL / g, there is a risk of a decrease in impact strength, and if it exceeds 0.85 dL / g, there is a risk of a decrease in moldability due to a decrease in fluidity.

[0031] In this disclosure, the reduced viscosity of the rubber-modified styrene-based resin is a value measured in a toluene solution at 30° C. and a concentration of 0.5 g / dL.

[0032] The method for producing the rubber-modified styrene-based resin is not particularly limited, but it can be produced by bulk polymerization (or solution polymerization) in which a styrene-based monomer (and a solvent) is polymerized in the presence of the rubber-like polymer (a), or bulk-suspension polymerization in which the reaction is changed to suspension polymerization during the course of the reaction, or emulsion graft polymerization in which a styrene-based monomer is polymerized in the presence of the rubber-like polymer (a) latex. In bulk polymerization, the rubber-like polymer (a) can be produced by continuously supplying a mixed solution containing the rubber-like polymer (a) and the styrene-based monomer, and optionally an organic solvent, an organic peroxide, and / or a chain transfer agent, to a polymerization apparatus consisting of a complete mixing reactor or a tank reactor and a plurality of tank reactors connected in series.

[0033] <<Styrene-based copolymer resin>> In the present embodiment, the styrene-based copolymer resin is a resin containing a styrene-based monomer unit and other monomers (e.g., unsaturated carboxylic acid-based monomer units) copolymerizable with the styrene-based monomer. For example, when the other monomers are unsaturated carboxylic acid-based monomer units, the styrene-based copolymer resin according to the present invention has a styrene-based monomer unit content of preferably 69 to 98% by mass, more preferably 74 to 96% by mass, and even more preferably 77 to 92% by mass, when the total content of the styrene-based monomer units and the unsaturated carboxylic acid-based monomer units is taken as 100% by mass. By making the content 69% by mass or more, the flowability of the resin can be improved. On the other hand, by making the content of the styrene-based monomer unit 98% by mass or less, it becomes difficult to make a desired amount of an unsaturated carboxylic acid-based monomer unit, which is an example of the other monomer, exist, and it becomes difficult to obtain the effects described below due to these monomer units.

[0034] The unsaturated carboxylic acid monomer in the present embodiment includes an unsaturated carboxylic acid monomer and an unsaturated carboxylic acid ester monomer.

[0035] In the preferred styrene-based copolymer resin of this embodiment, the unsaturated carboxylic acid monomer unit plays a role in improving heat resistance. When the total content of the styrene-based monomer unit, the unsaturated carboxylic acid monomer unit, and the unsaturated carboxylic acid ester monomer unit in the styrene-based copolymer resin is taken as 100% by mass, the content of the unsaturated carboxylic acid monomer unit is preferably 2 to 16% by mass, more preferably 4 to 14% by mass, and even more preferably 8 to 13% by mass. By making the content 2% by mass or more, the dispersibility of the (B) component is improved and the heat resistance can be further improved. On the other hand, by making the content 16% by mass or less, when the flame-retardant styrene-based resin composition of this embodiment is used as a master batch, excellent dispersibility in the styrene-based resin is exhibited, and the flame retardancy can be improved, and the molded appearance, the flowability of the resin, and the mechanical properties are further improved.

[0036] Generally, styrene-methacrylic acid-based resins including styrene-methacrylic acid-methyl methacrylate copolymer resins, which are one form of the styrene-based copolymer resins in the present invention, are mostly produced by radical polymerization on an industrial scale. However, in this embodiment, in order to suppress the gelling reaction in the devolatilization step, various alcohols can be added to the polymerization system to carry out the polymerization.

[0037] The unsaturated carboxylic acid ester monomer can be used to suppress the dehydration reaction of the unsaturated carboxylic acid monomer through intermolecular interaction with the unsaturated carboxylic acid monomer and to improve the mechanical strength of the resin. Furthermore, the unsaturated carboxylic acid ester monomer also contributes to improving the resin properties such as weather resistance and surface hardness.

[0038] In this embodiment, when the total content of the styrene monomer unit, the unsaturated carboxylic acid monomer unit, and the unsaturated carboxylic acid ester monomer unit is taken as 100% by mass, the content of the unsaturated carboxylic acid ester monomer unit is preferably 0 to 15% by mass, more preferably 1 to 12% by mass, and even more preferably 2 to 10% by mass. By setting the content to 15% by mass or less, the fluidity of the resin can be improved and water absorption can be suppressed. In addition, by setting the lower limit of the content of the unsaturated carboxylic acid ester monomer unit to 0% by mass, the heat resistance can be improved and the cost can be reduced, but from the above viewpoint, the content of the unsaturated carboxylic acid ester monomer unit can also be set to more than 0% by mass.

[0039] In addition, when an unsaturated carboxylic acid monomer and an unsaturated carboxylic acid ester monomer unit are bonded side by side, if a high-temperature, high-vacuum devolatilizer is used, a dealcoholization reaction may occur under certain conditions, resulting in the formation of a six-membered cyclic acid anhydride. The styrene-based copolymer resin of the present embodiment may contain this six-membered cyclic acid anhydride, but since this reduces the fluidity, it is preferable that the amount of the six-membered cyclic acid anhydride produced is as small as possible.

[0040] In the present embodiment, the contents of the styrene-based monomer unit (e.g., styrene monomer unit), the unsaturated carboxylic acid monomer unit (e.g., methacrylic acid monomer unit), and the unsaturated carboxylic acid ester monomer unit (e.g., methyl methacrylate monomer unit) in the styrene-based copolymer resin are respectively measured by proton nuclear magnetic resonance ( 1 It can be calculated from the integral ratio of the spectrum measured by a H-NMR spectrometer.

[0041] In the present embodiment, the styrene-based copolymer resin may further contain monomer units other than the styrene-based monomer units and unsaturated carboxylic acid-based monomer units (e.g., unsaturated carboxylic acid monomer units and unsaturated carboxylic acid ester monomer units), which are examples of other monomers, within a range that does not impair the effects of the present invention. However, the styrene-based copolymer resin in the present invention is preferably typically composed of styrene-based monomer units, unsaturated carboxylic acid monomer units, and / or unsaturated carboxylic acid ester monomer units.

[0042] The styrene-based monomer constituting the styrene-based copolymer resin of the present embodiment is not particularly limited, but examples thereof include styrene, α-methylstyrene, α-methyl-p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, ethylstyrene, isobutylstyrene, t-butylstyrene, bromostyrene, indene and other styrene derivatives. From an industrial viewpoint, styrene is preferred as the styrene-based monomer. These styrene-based monomers can be used alone or in combination of two or more.

[0043] The unsaturated carboxylic acid monomer constituting the styrene-based copolymer resin of this embodiment is not particularly limited, but examples thereof include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, etc. As the unsaturated carboxylic acid monomer, methacrylic acid is preferred because it has a large effect of improving heat resistance, is liquid at room temperature, and has excellent handling properties. These unsaturated carboxylic acid monomers can be used alone or in combination of two or more.

[0044] The unsaturated carboxylate monomer constituting the styrene copolymer resin of the present embodiment is not particularly limited, but examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and cyclohexyl (meth)acrylate. As the (meth)acrylate monomer, methyl (meth)acrylate is preferred because it has little effect on the decrease in heat resistance. These unsaturated carboxylate monomers may be used alone or in combination of two or more.

[0045] Suitable styrene-based copolymer resins for this embodiment include styrene-methacrylic acid copolymers, styrene-methyl methacrylate copolymers, styrene-methacrylic acid-methyl methacrylate copolymers, styrene-acrylic acid copolymers, styrene-methyl acrylate copolymers, styrene-acrylic acid-methyl acrylate copolymers, styrene-methyl methacrylate-butyl methacrylate copolymers, styrene-butyl methacrylate copolymers, and styrene-maleic anhydride copolymers.

[0046] In this embodiment, the weight average molecular weight (Mw) of the styrene copolymer resin is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, and further preferably 140,000 to 240,000. When the weight average molecular weight (Mw) is 100,000 to 350,000, a resin having a better balance between mechanical strength and fluidity is obtained, and the amount of gel contamination is small. The weight average molecular weight (Mw) is a value obtained by using gel permeation chromatography and converting it into a standard polystyrene equivalent.

[0047] In this embodiment, the polymerization method of the styrene-based alkoxy group polymerization resin is not particularly limited, but for example, a bulk polymerization method or a solution polymerization method can be suitably adopted as a radical polymerization method. The polymerization method mainly includes a polymerization step of polymerizing a polymerization raw material (monomer component) and a devolatilization step of removing volatile matters such as unreacted monomers and polymerization solvent from the polymerization product.

[0048] Hereinafter, an example of a method for polymerizing a styrene-based copolymer resin that can be used in the present embodiment will be described.

[0049] When the polymerization raw materials are polymerized to obtain a styrene-based copolymer resin, a polymerization initiator and a chain transfer agent are typically contained in the polymerization raw material composition.

[0050] Examples of the polymerization initiator used in the polymerization of the styrene-based copolymer resin include organic peroxides, such as peroxyketals such as 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)cyclohexane, and n-butyl-4,4-bis(t-butylperoxy)valerate, dialkyl peroxides such as di-t-butyl peroxide, t-butylcumyl peroxide, and dicumyl peroxide, diacyl peroxides such as acetyl peroxide and isobutyryl peroxide, peroxydicarbonates such as diisopropyl peroxydicarbonate, peroxyesters such as t-butyl peroxyacetate, ketone peroxides such as acetylacetone peroxide, and hydroperoxides such as t-butyl hydroperoxide. Among them, 1,1-bis(t-butylperoxy)cyclohexane is preferred from the viewpoint of decomposition rate and polymerization rate.

[0051] Examples of the chain transfer agent used in the polymerization of the styrene-based copolymer resin include α-methylstyrene linear dimer, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-octyl mercaptan.

[0052] As a polymerization method for the styrene-based copolymer resin, solution polymerization using a polymerization solvent can be adopted as necessary. Examples of the polymerization solvent used include aromatic hydrocarbons, such as ethylbenzene, and dialkyl ketones, such as methyl ethyl ketone, and each of them may be used alone or in combination of two or more. Other polymerization solvents, such as aliphatic hydrocarbons, can be further mixed with aromatic hydrocarbons as long as the solubility of the polymerization product is not reduced. These polymerization solvents are preferably used in an amount not exceeding 25 parts by mass relative to 100 parts by mass of the total monomers. If the amount of the polymerization solvent exceeds 25 parts by mass relative to 100 parts by mass of the total monomers, the polymerization rate is significantly reduced and the mechanical strength of the obtained resin tends to be significantly reduced. It is preferable to add the polymerization solvent at a ratio of 5 to 20 parts by mass relative to 100 parts by mass of the total monomers before polymerization, as this makes it easier to uniformize the quality and is also preferable in terms of polymerization temperature control.

[0053] In this embodiment, the apparatus used in the polymerization step for obtaining a styrene-based copolymer resin is not particularly limited, and may be appropriately selected according to the polymerization method of the styrene-based resin. For example, when bulk polymerization is adopted, a polymerization apparatus having one or more completely mixed reactors connected together can be used. There is also no particular limit to the devolatilization step. When bulk polymerization is adopted, polymerization is continued until the final amount of unreacted monomer is preferably 50 mass% or less, more preferably 40 mass% or less, and devolatilization treatment is performed by a known method in order to remove volatile matters such as unreacted monomer. More specifically, for example, a normal devolatilization apparatus such as a flash drum, a twin-screw devolatilizer, a thin film evaporator, an extruder, etc. can be used, but a devolatilization apparatus with a small retention portion is preferred. The temperature of the devolatilization treatment is usually about 190 to 280°C, and from the viewpoint of suppressing the formation of a six-membered ring acid anhydride due to the adjacency of an unsaturated carboxylic acid monomer (e.g., methacrylic acid) and an unsaturated carboxylic acid ester monomer (e.g., methyl methacrylate), 190 to 260°C is more preferred. The pressure in the devolatilization treatment is usually about 0.13 to 4.0 kPa, preferably 0.13 to 3.0 kPa, and more preferably 0.13 to 2.0 kPa. Desirable devolatilization methods include, for example, a method of removing volatile matters by reducing pressure under heating, and a method of removing volatile matters through an extruder or the like designed for the purpose of removing volatile matters.

[0054] <Flame retardant (B): (B) component> The flame-retardant styrene-based resin composition of the present embodiment contains 1.0 to 30 mass% of the flame retardant (B) relative to 100 mass% of the flame-retardant styrene-based resin composition, preferably 2.0 to 25 mass%, more preferably 2.5 to 20 mass%, and even more preferably 3.0 to 18 mass%. In this embodiment, the flame retardant (B) contains at least one phosphinate selected from the group consisting of phosphinates and diphosphinates, and preferably the phosphinates account for 70 mass% or more of the entire flame retardant (B) (100 mass%). Therefore, the flame retardant (B) in this embodiment may contain a known flame retardant other than the above phosphinates in an amount of 30 mass% or less of the entire flame retardant (B) (100 mass%). In this specification, the phosphinates is a general term for both phosphinates and / or diphosphinates.

[0055] In this embodiment, the phosphinate is represented by the following general formula (1). [ka] [In the above general formula (1), R 11 and R 12 are each independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; M 1 is at least one selected from the group consisting of calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion, and protonated nitrogen base; a is 1 represents an ionic valence, and is an integer of 1 to 3; m 1 is an integer between 1 and 3; a=m 1 R 11 and R 12 If there are multiple of each, 11 and R 12 may be the same or different.]

[0056] In this embodiment, the diphosphinate is represented by the following general formula (2). [ka] [In the above general formula (2), R 21 and R 22are each independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; L 23 is a linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 6 to 10 carbon atoms, or an arylalkylene group having 6 to 10 carbon atoms; M 2 is at least one selected from the group consisting of calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion, and protonated nitrogen base; b is M 2 represents an ionic valence, and is an integer of 1 to 3; m 2 is an integer from 1 to 3; i is an integer of 1 or 2; b×i=2m 2 R 21 and R 12 If there are multiple of each, 21 and R 22 may be the same or different.

[0057] In the above general formula (1) or (2), examples of the linear or branched alkyl group having 1 to 6 carbon atoms include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, or a hexyl group, and branched alkyl groups such as an isopropyl group, an isobutyl group, a s-butyl group, a t-butyl group, an isoamyl group, or a t-amyl group. In the above general formula (1) or (2), the aryl group having 6 to 10 carbon atoms may have a monocyclic or condensed ring structure, for example, a phenyl group or a naphthyl group. In the above general formula (1) or (2), examples of the linear or branched alkylene group having 1 to 10 carbon atoms include groups in which one hydrogen atom has been removed from the above linear or branched alkyl group having 1 to 6 carbon atoms. In the above general formula (1) or (2), examples of the arylene group having 6 to 10 carbon atoms include groups in which one hydrogen atom has been removed from the above aryl group having 6 to 10 carbon atoms. In the above general formula (1) or (2), examples of the alkylarylene group having 6 to 10 carbon atoms include a methylphenylene group, an ethylphenylene group, a tert-butylphenylene group, a methylnaphthylene group, an ethylnaphthylene group, and a tert-butylnaphthylene group. In the above general formula (1) or (2), examples of the arylalkylene group having 6 to 10 carbon atoms include a phenylmethylene group, a phenylethylene group, a phenylpropylene group, and a phenylbutylene group. In the above general formula (1), R 11 and R 12 is preferably each independently a linear alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. In the above general formula (1), M 1 is preferably calcium, magnesium, aluminum, or zinc. 1 represents the ionic valence, which is 2 or 3. In the above general formula (2), R 21 and R 22 is preferably each independently a linear alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. In the above general formula (2), L 23 are each preferably independently a linear alkylene group having 1 to 6 carbon atoms or an arylene group having 6 to 10 carbon atoms. In the above general formula (2), M 2 is preferably calcium, magnesium, aluminum, or zinc. 2 represents the ionic valence, which is 2 or 3. Phosphinates have excellent electrical properties, making them suitable for flame-retardant materials that require insulation. They also have excellent hydrolysis properties, making them suitable for use in high-temperature, high-humidity environments, and are highly recyclable.

[0058] The phosphinates used in the present embodiment are produced in an aqueous solution using, inter alia, phosphinic acid and a metal carbonate, metal hydroxide or metal oxide, and are essentially monomeric compounds, but also include polymeric phosphinates with a degree of condensation of 1 to 3, depending on the reaction conditions and in some circumstances.

[0059] Such phosphinates are not particularly limited, and examples thereof include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methane di(methylphosphinate), magnesium methane di(methylphosphinate), aluminum methane di(methylphosphinate), zinc methane di(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), benzene-1,4- Examples of such phosphinate include magnesium (dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate), zinc benzene-1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate. Of these, calcium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, aluminum ethylmethylphosphinate, aluminum ethylbutylphosphinate, aluminum dibutylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate, and zinc diethylphosphinate are preferred, and aluminum diethylphosphinate is more preferred. Commercially available phosphinates include, but are not limited to, Exolit (registered trademark) OP1230, OP1240, OP1311, OP1312, OP930, and OP935 manufactured by Clariant Japan K.K.

[0060] In this embodiment, the phosphinate salts are preferably granular. When the phosphinate salts are granular, the average particle size of the phosphinate salts is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 20 μm or less, from the viewpoint of improving the mechanical strength and appearance of the molded article obtained by molding the flame-retardant resin composition of this embodiment, and it is preferable to use a powder of the phosphinate salts pulverized to this particle size. In addition, the lower limit of the average particle size of the phosphinate salts is preferably 0.5 μm or more, more preferably 1.5 μm or more, and even more preferably 3.5 μm or more. The average particle size of the phosphinate salts is preferably more than 0.5 μm and 23 μm, more preferably more than 1 μm and 21 μm or less. When a powder having the above preferred average particle size is used, not only high flame retardancy is exhibited, but also impact strength is remarkably increased, so it is particularly preferable. The method for measuring the average particle size of the granular phosphinate salts is based on the volumetric particle size measured using a laser diffraction / scattering particle size distribution measuring device. The value is measured using a 3% isopropanol aqueous solution as the dispersion medium for the phosphinate salts. Specifically, the average particle size can be obtained by using a laser diffraction / scattering particle size distribution measuring device LA-910 (manufactured by Horiba, Ltd.) to perform a blank measurement using a dispersion medium of 3% isopropanol aqueous solution, and then putting the measurement sample so that the transmittance is set to the specified value (95% to 70%). The sample is dispersed in the dispersion medium by irradiating ultrasonic waves for 1 minute.

[0061] <Hindered amine compound (C): Component (C)> The flame-retardant styrene-based resin composition according to the present embodiment contains a hindered amine-based compound (C). The content of the hindered amine-based compound (C) is 0.2 to 3 mass%, preferably 0.3 to 2.5 mass%, and more preferably 0.5 to 2.0 mass parts, relative to 100 mass% of the total amount of the (A), (B) and (C) components. If it is 0.2 mass parts or more, flame retardancy and light resistance are obtained. Also, if it is 3.0 mass parts or less, heat resistance is excellent.

[0062] The hindered amine compound (C) according to the present embodiment may be an NH type in which the imino group (>NH) of the piperidine ring remains NH, an N-methyl type in which the H of the imino group of the piperidine ring is replaced with a methyl group, or an NOR type in which the H of the imino group of the piperidine ring is replaced with an alkoxyl group (-OR (R represents a cycloalkyl group, an aralkyl group, or an aryl group)). The hindered amine compound (C) according to the present embodiment is preferably an NOR type (alkoxyimino group) hindered amine compound. The NOR type hindered amine compound has a large flame retardant interaction with the flame retardant (B), and can provide high flame retardancy. It is presumed that the NOR type hindered amine efficiently decomposes the flame retardant (B) during combustion, promotes combustion residue, and also develops a flame retardant interaction due to radical trip in the gas phase.

[0063] The alkoxyimino group of the NOR (alkoxyimino group) type hindered amine compound has an N-alkoxyl group (>N-OR) structure, as opposed to an NH type in which the imino group (>NH) of the piperidine ring remains NH or an N-methyl type in which H is replaced with a methyl group, and the N-alkoxyl group captures an alkylperoxy radical (R'O2·) and easily becomes a radical, thereby exerting a flame retardant effect. On the other hand, when an N-methyl type hindered amine compound or an NH type hindered amine compound is added to the flame retardant styrene resin composition of the present invention, there is a risk of a decrease in flame retardancy.

[0064] The above alkoxyl group (-OR) is not limited to an alkoxyl group in which oxygen is bonded to an alkyl group (R), and R includes, in addition to an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, and the like. Specific examples of the alkoxyl group include a methoxy group, a propoxy group, a cyclohexyloxy group, and an octyloxy group. In particular, from the viewpoint of suppressing bleed-out of component (B) or component (C) from a molded article (e.g., a sheet or film) formed from the flame-retardant styrene-based resin composition of the present embodiment, a propoxy group, a cyclohexyloxy group, an octyloxy group, or the like, which increase the molecular weight of the NOR-type hindered amine-based compound, are preferred.

[0065] The NOR type hindered amine compound used in the present embodiment is not particularly limited as long as it has an N-alkoxyl group (>N-OR) structure.Specific examples of suitable NOR type hindered amine compounds include those described in JP-T-2002-507238, WO-2005 / 082852, WO-2008 / 003605, etc.

[0066] In addition, the NOR type hindered amine compound is preferably a polymer type. The polymer type is generally an oligomer or polymer compound. The polymer type can reduce mold deposits during molding and has excellent flame retardancy and heat resistance.

[0067] In this embodiment, the hindered amine compound (C) is represented by the following general formula (1): [ka] It is preferable that the formula is represented by the formula: (In the above general formula (1), X 1 , X 2 , X 3 and X 4 are each independently represented by the following general formula (a): [ka] It is expressed as R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an unsubstituted or sor a phenylalkyl group having 7 to 9 carbon atoms substituted with [ka] L 1 , L 2 and L 3 each independently represents an alkylene group having 2 to 12 carbon atoms, In the above general formula (a), Y 1 , Y 2 , Y 3 and Y 4 are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an unsubstituted or s or a phenylalkyl group having 7 to 9 carbon atoms substituted with Y 1 , Y 2 , Y 3 and Y 4 At least one of the above is a group represented by general formula (b), In the above general formula (b), R 4 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an oxygen atom radical, a hydroxyl group, -CHCN, an alkoxy group having 1 to 18 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, or an unsubstituted or group having one or more hydrogen atoms in R s represents a phenylalkyl group having 7 to 9 carbon atoms substituted with R i , R ii , R iii and R iv each independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, m represents 0 to 100, R s represents an alkyl group having 1 to 6 carbon atoms. It is preferable that the compound is a high molecular type NOR type hindered amine compound represented by the following formula:

[0068] In the above general formula (1), R i , R ii , R iii and R iv Each of independently represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group. In the preferred general formula (a) in the above general formula (1), Y 1 Or Y 2 At least one of the following is a group represented by general formula (b); and Y 3 Or Y 4 At least one of the above is a group represented by general formula (b). In another preferred formula (a) in the above general formula (1), Y 1 and Y 2 is a group represented by general formula (b), and Y 3 Or Y 4 one of them is a group represented by general formula (b). In another preferred formula (a) in the above general formula (1), Y 1 is an alkyl group having 1 to 6 carbon atoms, and Y 2 is a group represented by general formula (b), and Y 3 is an alkyl group having 1 to 6 carbon atoms, and Y 4 one of them is a group represented by general formula (b). In the above general formula (1), R 1 and R 2 are each independently preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, and more preferably a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. In the above general formula (b), R 4 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms (including linear, branched, or cyclic alkyl), an oxygen atom radical, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms (including linear, branched, or cyclic alkoxy), or an unsubstituted or s R preferably represents a phenylalkyl group having 7 to 9 carbon atoms substituted with 4 More preferably, represents a cyclic alkoxy group having 3 to 6 carbon atoms. The oligomeric or polymeric NOR type hindered amine compound preferably has 2 to 100 repeating units, and more preferably 5 to 80 repeating units, represented by general formula (a).

[0069] Specific examples of the NOR type hindered amine compound include the following compounds: 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine; 2,2,6,6-tetramethyl-4-piperidyl)sebacate; 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxyethylamino)-s-triazine; bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)adipate; Oligomeric compounds which are condensation products of 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) with 2,4-dichloro-6-[(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine; oligomeric compounds which are condensation products of 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) with 2,4-dichloro-6-[(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine Oligomeric compounds which are condensation products of 2,4-dichloro-6-[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine with 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin-4-yl)-6-chloro-s-triazine]; peroxidized 4-butylamino-2,2,6,6-tetramethylpiperidine, 2,4,6-trichloro-s-triazine, cyclohexane and N,N'-ethane-1,2-diylbis(1,3-propanediamine). Reaction products with (N,N',N''-tris{2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)n-butylamino]-s-triazin-6-yl}-3,3'-ethylenediiminodipropylamine); bis(1-undecanoxy-2,2,6,6-tetramethylpiperidin-4-yl)carbonate; 1-undecyloxy-2,2,6,6-tetramethylpiperidin-4-one; bis(1-stearyloxy-2,2,6,6-tetramethylpiperidin-4-yl)carbonate.

[0070] Examples of commercially available NOR type hindered amine compounds include FlamestaBNOR116FF, TINUVIN NOR371, TINUVIN XT850FF, TINUVIN XT855FF, and TINUVIN PA123 manufactured by BASF, and LA-77Y, LA-81, and FP-T80 manufactured by ADEKA CORPORATION. The NOR type hindered amine compounds in the present embodiment may be used alone or in combination of two or more.

[0071] Examples of the hindered amine compound in this embodiment include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, tetrakis(2,2,6,6-tetramethyl-4- piperidyl)-1,2,3,4-butane tetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butane tetracarboxylate, bis(2,2,6,6-tetramethyl-4-piperidyl)·di(tridecyl)-1,2,3,4-butane tetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)·di(tridecyl)-1,2,3,4-butane tetracarboxylate, bis(1,2,2,4,4-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di- tert-Butyl-4-hydroxybenzyl)malonate, 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis[2,4-bis(N-butyl -N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8-12-tetraazadodecane, 1,6,11-tris[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-yl]aminoundecane, 1,6,11-tris[2,Examples of the hindered amine compounds include 4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl)aminoundecane. These may be used alone or in combination of two or more.

[0072] <Optional addition ingredients> In addition to the above components (A) to (C), the flame-retardant styrene-based resin composition of the present embodiment, the flame-retardant masterbatch using the flame-retardant styrene-based resin composition as a masterbatch, and the masterbatch composition containing the flame-retardant masterbatch may contain optional additives such as conventionally known additives and processing aids, as necessary, within a range that does not impair the effects of the present invention. Examples of these additives and processing aids include antioxidants, weathering agents, lubricants, antistatic agents, and fillers.

[0073] Examples of the antioxidant include phenol-based compounds, phosphorus-based compounds, and thioether-based compounds.

[0074] Examples of the phenol-based antioxidant include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide], 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylene Bis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-m-cresol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4-sec-butyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3 ,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol, stearyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate methyl ]methane, thiodiethylene glycol bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylene bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyric acid]glycol ester, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl]terephthalate, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, 3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, triethylene glycol bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], etc. These may be used alone or in combination of two or more.

[0075] Examples of the phosphorus-based antioxidant include tris(2,4-di-tert-butylphenyl)phosphite, trisnonylphenyl phosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, tridecyl phosphite, octyldiphenyl phosphite, di(decyl)monophenyl phosphite, di(tridecyl)pentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, and the like. tetra(tridecyl)isopropylidenediphenol diphosphite, tetra(tridecyl)-4,4'-n-tetradecylphenyl diphosphite, bis(2,4-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, tetra(tridecyl)isopropylidenediphenol diphosphite, tetra(tridecyl)-4,4'-n- Butylidenebis(2-tert-butyl-5-methylphenol)diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butanetriphosphite, tetrakis(2,4-di-tert-butylphenyl)biphenylene diphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis(4,6-tert-butylphenyl)-2-ethylhexylphospha phosphite, 2,2'-methylenebis(4,6-tert-butylphenyl)-octadecylphosphite, 2,2'-ethylidenebis(4,6-di-tert-butylphenyl)fluorophosphite, tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol, etc. These may be used alone or in combination of two or more.

[0076] Examples of the thioether-based antioxidant include dialkyl thiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and pentaerythritol tetra(β-alkylmercaptopropionate)s. These may be used alone or in combination of two or more.

[0077] As the weatherproofing agent, an ultraviolet absorbing agent or the like can be used. Examples of the ultraviolet absorbing agent include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole. 2-(2'-hydroxyphenyl)benzotriazoles such as 2,2'-methylenebis(4-tert-octyl-6-(benzotriazolyl)phenol), 2-(2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl)benzotriazole; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2,4-di-tert-amylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, Benzoates such as 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyloxanilide, and other substituted oxanilides; cyanoacrylates such as ethyl-α-cyano-β,β-diphenylacrylate, methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate, and other cyanoacrylates; triaryltriazines such as 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine, 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine, and other triaryltriazines. These may be used alone or in combination of two or more.

[0078] As the lubricant, fatty acid amides, fatty acid esters, fatty acids, fatty acid metal salts, etc. can be used.

[0079] Examples of the aliphatic amide lubricant include stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, ethylene biserucic acid amide, ethylene bislauric acid amide, etc. These may be used alone or in combination of two or more.

[0080] Examples of the aliphatic ester-based lubricants include methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl erucate, methyl behenate, butyl laurate, butyl stearate, isopropyl myristate, isopropyl palmitate, octyl palmitate, coconut fatty acid octyl ester, octyl stearate, tallow fatty acid octyl ester, lauryl laurate, stearyl stearate, behenyl behenate, cetyl myristate, esters of linear, unbranched, saturated monocarboxylic acid having 28 to 30 carbon atoms (hereinafter abbreviated as montanic acid) and ethylene glycol, esters of montanic acid and glycerin, montanic acid, glycerin ... Examples of the montanic acid include esters of montanic acid and butylene glycol, esters of montanic acid and trimethylolethane, esters of montanic acid and trimethylolpropane, esters of montanic acid and pentaerythritol, glycerin monostearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, etc. These may be used alone or in combination of two or more.

[0081] Specific examples of the saturated fatty acids among the above fatty acid-based lubricants include lauric acid (dodecanoic acid), isodecanoic acid, tridecylic acid, myristic acid (tetradecanoic acid), pentadecylic acid, palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid), stearic acid (octadecanoic acid), isostearic acid, tuberculostearic acid (nonadecanoic acid), 2-hydroxystearic acid, arachidic acid (icosanoic acid), behenic acid (docosanoic acid), lignoceric acid (tetradocosanoic acid), cerotic acid (hexadocosanoic acid), montanic acid (octadocosanoic acid), and melissic acid, and in particular, lauric acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, and montanic acid.

[0082] Specific examples of the unsaturated fatty acids among the above fatty acid-based lubricants include myristoleic acid (tetradecenoic acid), palmitoleic acid (hexadecenoic acid), oleic acid (cis-9-octadecenoic acid), elaidic acid (trans-9-octadecenoic acid), ricinoleic acid (octadecadienoic acid), vaccenic acid (cis-11-octadecenoic acid), linoleic acid (octadecadienoic acid), linolenic acid (9,11,13-octadecatrienoic acid), elestearic acid (9,11,13-octadecatrienoic acid), gadoleic acid (icosanoic acid), erucic acid (docosanoic acid), nervonic acid (tetradocosanoic acid), etc. These may be used alone or in combination of two or more.

[0083] Examples of the fatty acid metal salt lubricant include lithium salts, calcium salts, magnesium salts, and aluminum salts of the fatty acid of the fatty acid lubricant. These may be used alone or in combination of two or more.

[0084] The antistatic agent may be a cationic, anionic, nonionic, amphoteric, or fatty acid partial ester such as glycerin fatty acid monoester.Specific examples of the antistatic agent include alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts, benzalkonium salts, N,N-bis(2-hydroxyethyl)-N-(3-dodecyloxy-2-hydroxypropyl)methyl ammonium methosulfate, (3-lauryl amide propyl)trimethyl ammonium methyl sulfate, stearamidopropyl dimethyl-2-hydroxyethyl ammonium nitrate, stearamidopropyl dimethyl-2-hydroxyethyl ammonium phosphate, cationic polymers, alkyl sulfonates, alkyl benzene sulfonates, sodium alkyl diphenyl ether disulfonate, alkyl nitrate salts, phosphorus Examples of such esters include alkyl ester salts, alkyl phosphate amine salts, stearic acid monoglyceride, pentaerythritol fatty acid esters, sorbitan monopalmitate, sorbitan monostearate, diglycerol fatty acid esters, alkyldiethanolamines, alkyldiethanolamine fatty acid monoesters, alkyldiethanolamides, polyoxyethylene dodecyl ethers, polyoxyethylene alkylphenyl ethers, polyethylene glycol monolaurates, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyether block copolymers, cetyl betaine, and hydroxyethyl imidazoline sulfate esters. These may be used alone or in combination of two or more.

[0085] As the filler, talc, calcium carbonate, barium sulfate, carbon fiber, mica, wollastonite, whisker, etc. can be used.

[0086] In this embodiment, the flame-retardant styrene-based resin composition, the flame-retardant master batch using the flame-retardant styrene-based resin composition as a master batch, and the master batch composition containing the flame-retardant master batch may contain optional additives such as the above-mentioned additives and processing aids, antiblocking agents, colorants, antiblooming agents, surface treatment agents, antibacterial agents, and anti-viscosity agents (anti-viscosity agents such as silicone oil described in JP 2009-120717 A, monoamide compounds of higher aliphatic carboxylic acids, and monoester compounds obtained by reacting higher aliphatic carboxylic acids with monohydric to trihydric alcohol compounds). The total content of optional additives such as additives and processing aids may be 0.05 to 5% by mass with respect to the total amount of the flame-retardant styrene-based resin composition (100% by mass).

[0087] The flame-retardant styrene-based resin composition of the present embodiment may essentially consist of only the components (A), (B), (C) and optional additional components, or may consist of only the components (A), (B) and (C).

[0088] The phrase "consisting essentially of only the components (A), (B), (C) and any optional additional components" means that 95 to 100% by mass (preferably 98 to 100% by mass) of the flame-retardant styrene-based resin composition is made up of the components (A), (B) and (C), or the components (A), (B), (C) and any optional additional components. The flame-retardant styrene-based resin composition of the present embodiment may contain inevitable impurities in addition to the components (A), (B), (C) and any optional additional components, as long as the effects of the present invention are not impaired.

[0089] <Method for producing flame-retardant styrene-based resin composition> The flame-retardant styrene-based resin composition of the present embodiment can be produced by melt-kneading each component by any method. For example, a high-speed stirrer such as a Henschel mixer, a batch-type kneader such as a Banbury mixer, a single-screw or twin-screw continuous kneader, a roll mixer, etc. can be used alone or in combination. The heating temperature during kneading is usually selected in the range of 180 to 260°C.

[0090] [Physical properties of flame-retardant styrene-based resin composition] <Flame retardancy> The flame retardancy of the flame-retardant styrene-based resin composition of this embodiment is preferably within the standard in the UL94 vertical flame test (UL94-V test), that is, the flame retardancy class is preferably V-0 to V-2. In the present disclosure, flame retardancy can be evaluated by the method described in the section [Examples] below.

[0091] <Dielectric constant / dielectric tangent> The dielectric constant of the flame-retardant styrene-based resin composition of the present embodiment is preferably 3 or less, more preferably 2.5 or less. The dielectric loss tangent is 0.02 or less, more preferably 0.01 or less. If the dielectric constant is greater than 3 and the dielectric loss tangent is greater than 0.02, the dielectric loss increases at high frequencies of 0.3 GHz or more, causing defects in the product. In this disclosure, the dielectric constant and dielectric loss tangent are values ​​measured at 10 GHz in accordance with JIS C2138.

[0092] <Light resistance> The light resistance of the flame-retardant styrene-based resin composition of the present embodiment is preferably such that the color difference ΔE is 10 or less, more preferably 5 or less. If the color difference ΔE is greater than 10, the composition may not be usable outdoors due to reduced strength, and may discolor indoors, impairing the design and recyclability. In this disclosure, the color difference ΔE is a value measured in accordance with JIS K7103 and JIS K7105 using a xenon lamp weather meter, maintaining the temperature of the black panel at 63°C, and measuring the color difference (ΔE) after 300 hours.

[0093] [Molded products] The flame-retardant styrene-based resin composition of the present embodiment can be used to produce a molded article by the above-mentioned melt kneading molding machine, or by using pellets of the obtained flame-retardant styrene-based resin composition as a raw material, through injection molding, injection compression molding, extrusion molding, blow molding, press molding, vacuum molding, foam molding, or the like.

[0094] The flame-retardant styrene-based resin composition of the present embodiment is preferably used for molded articles, preferably injection molded articles (including injection compression), office automation equipment such as copiers, fax machines, televisions, radios, tape recorders, video decks, personal computers, printers, telephones, information terminals, refrigerators, and microwave ovens, home appliances, housings and various parts of electric and electronic devices, foamed insulation materials, insulating films, and the like. EXAMPLES

[0095] Hereinafter, the embodiments of the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to these examples in any way.

[0096] "Measurement and evaluation methods" The physical properties of the flame-retardant styrene-based resin compositions obtained in the respective Examples and the resin compositions obtained in the Comparative Examples (hereinafter referred to as styrene-based compositions) were measured and evaluated according to the following methods.

[0097] (1) Flame retardancy Test pieces (b) (size: 127 mm × 12.7 mm, thickness: 1.5 mm or 0.8 mm) prepared by the method described below were used to evaluate flame retardancy in accordance with the UL94 vertical flame test (UL94-V test) using a 50 W test flame. The flame of a gas burner was applied to the test piece (b) to evaluate the degree of combustion. The flame retardancy grade indicates the flame retardancy class as classified by the UL94-V test. The test was performed on five pieces for each test piece and the judgment was made. The classification method is as follows: V-0: Total burning time of 5 sticks is 50 seconds or less, maximum burning time is 10 seconds or less, no cotton dripping ignition V-1: Total burn time of 5 sticks is 250 seconds or less, maximum burn time is 30 seconds or less, no cotton dripping ignition V-2: Total burn time of 5 sticks is 250 seconds or less, maximum burn time is 30 seconds or less, cotton dripping may ignite Not V: Not compliant with UL94

[0098] (2) Dielectric constant and dielectric tangent The dielectric constant and dielectric properties of the styrene-based composition were measured at 10 GHz using a PNA-L network analyzer N5230A (manufactured by Agilent Technologies, Inc.) in accordance with JIS C2138 (200° C., load 49 N).

[0099] (3) Light resistance Test piece (a) prepared by the method described below was used and evaluated in accordance with JIS K7103 and JIS K7105. That is, a xenon lamp weather meter (Ci65, manufactured by Atlas Co., Ltd.) was used to maintain the temperature of the black panel at 63°C, and the color difference (ΔE) between the start of measurement and 300 hours after the start of measurement was evaluated. ΔE was measured under the following conditions using a spectrophotometer (manufactured by Nippon Denshoku Industries Co., Ltd.). (a) Lamp: Halogen lamp; 12V, 50W [NARVA] (b) Wavelength of light: 400-700 nm (c) Light source: C light source 2 degree field of view (d) Measuring hole: 30mm in diameter (e) Measurement target: reflected light

[0100] "Materials and their characteristics" The materials used in the examples and comparative examples are as follows. <Component (A)> < <hips>> A rubber-modified styrene-based resin, which is high-impact polystyrene (HIPS) with MFR of 7.0, was used. The HIPS used polybutadiene as a rubber-like polymer, and the rubber-like polymer content was 8.6% by mass. The average particle size of the high-impact polystyrene (HIPS) was 1.5 μm.

[0101] < <gpps>> Polystyrene with MFR 2.2 (GPPS, manufactured by PS Japan, G9401) was used.

[0102] <<Styrene-based copolymer resin>> A polymerization raw material composition liquid consisting of 71.3 parts by mass of styrene (ST), 7.3 parts by mass of methacrylic acid (MAA), 6.4 parts by mass of methyl methacrylate (MMA), 15.0 parts by mass of ethylbenzene, and 0.025 parts by mass of 1,1-bis(t-butylperoxy)cyclohexane was continuously supplied at a rate of 1.1 L / hour to a 4-L complete mixing reactor, then to a polymerization apparatus consisting of a 2-L laminar flow reactor, and further to a devolatilizer connected to a single-screw extruder for removing volatile matters such as unreacted monomers and polymerization solvent, successively to prepare a styrene-based copolymer resin. The polymerization reaction conditions in the polymerization step were a polymerization temperature of 122° C. in the complete mixing reactor and a polymerization temperature of 120 to 142° C. in the laminar flow reactor. The devolatilized unreacted gas was condensed in a condenser through which a coolant of −5° C. was passed, and recovered as an unreacted liquid. The styrene copolymer resin content in the final polymerization liquid was measured by the formula [(sample mass after drying / sample mass before drying)×100%] after drying the polymerization liquid at 215° C. for 30 minutes under reduced pressure of 2.5 kPa, and was found to be 65.6% by mass, and the weight average molecular weight was 214,000 (214,000). The composition of the styrene copolymer resin was 82.3% by mass of styrene monomer units, 9.8% by mass of methacrylic acid monomer units, and 7.9% by mass of methyl methacrylate monomer units. Each monomer unit was determined by proton nuclear magnetic resonance ( 1 The composition of the styrene copolymer resin was quantified from the integral ratio of the spectrum measured by a 1 H-NMR spectrometer. Sample preparation: 30 mg of resin pellets were dissolved in 0.75 mL of d6-DMSO by heating at 60°C for 4 to 6 hours. ·Measuring equipment: JNM ECA-500 manufactured by JEOL Ltd. Measurement conditions: Measurement temperature 25℃, observation nucleus 1 H, accumulation count 64, repeat time 11 seconds. Regarding the assignment of the spectrum measured in dimethyl sulfoxide deuterated solvent, the peaks at 0.5 to 1.5 ppm are hydrogen of α-methyl group of methacrylic acid, methyl methacrylate, and six-membered cyclic acid anhydride, the peaks at 1.6 to 2.1 ppm are hydrogen of methylene group of polymer main chain, the peak at 3.5 ppm is hydrogen of carboxylate ester (-COOCH3) of methyl methacrylate, and the peak at 12.4 ppm is hydrogen of carboxylate of methacrylic acid. In addition, the peak at 6.5 to 7.5 ppm is hydrogen of aromatic ring of styrene. Note that the content of six-membered cyclic acid anhydride is small in the resins of the present embodiment and the comparative example, so that quantification is usually difficult by this measurement method.

[0103] <(B) component> Aluminum phosphinate (also referred to as DEP-A in Tables 1 and 2) "Exolit OP1230 manufactured by Clariant Japan" Average particle size: 20 μm Aluminum phosphinate (also referred to as DEP-B in Tables 1 and 2) "Exolit OP930 manufactured by Clariant Japan" Average particle size 3 μm

[0104] <(C) component> Hindered amine compounds (also referred to as HALS-A in Tables 1 and 2) [BASF, Flamestat NOR116FF, NOR type polymer type] Hindered amine compounds (also referred to as HALS-B in Tables 1 and 2) [ADEKA Corporation, Adeka STAB LA-81 NOR type] Hindered amine compounds (also referred to as HALS-C in Tables 1 and 2) [ADEKA Corporation, Adeka STAB LA-77Y NH type]

[0105] <Additives> (Phenol-based antioxidant) Stearyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] [BASF, Irganox 1076] (Phosphorus-based antioxidant) Tris(2,4-di-tert-butylphenyl)phosphite [BASF, Irgafos168]

[0106] <Other> (Polyphenylene ether) Polyphenylene ether (Zylon S202A, manufactured by Asahi Kasei Corporation) was used. The polyphenylene ether resins used were as follows: Zylon S202A [Asahi Kasei Corporation] (Mz molecular weight 6.0 × 10 4 )

[0107] [Examples 1 to 9] In the composition ratio shown in Table 1, 0.2 parts by mass of Irganox1076 and Irgafos168 were added to 100 parts by mass of each component and components (A) to (C), and then premixed. The obtained premixes were mixed together and melt-extruded (screw rotation speed: 150 rpm, discharge rate: 10 kg / hr) at 180°C to 230°C using a twin-screw extruder (Toshiba Machine Co., Ltd., TEM-26SS) to prepare a pellet-shaped flame-retardant styrene-based resin composition. The pellet-shaped flame-retardant styrene-based resin composition thus obtained was molded using an injection molding machine manufactured by Japan Steel Works Co., Ltd. equipped with ISO527-2 multipurpose test piece type 1A at a cylinder temperature of 220°C, a mold temperature of 50°C, an injection pressure (gauge pressure 40-60 MPa), an injection speed (panel setting value) of 50%, and an injection time / cooling time = 5 sec / 20 sec to prepare a test piece (a), and each physical property was measured. In addition, a test piece (b) was prepared under the same conditions as the test piece (a) using a flat die having gates on both ends and dimensions of 127 mm×12.7 mm×thickness of 0.8 mm, and flame retardancy was measured. The experimental results of Examples 1 to 9 are shown in Table 1.

[0108] [Table 1]

[0109] [Comparative Examples 1 to 6] Comparative Examples 1 to 6 were carried out in the same manner as Example 1, except that the compositions were changed as shown in Table 1. The results of the measurements and evaluations of the various physical properties are shown in Table 2.

[0110] [Table 2]

[0111] As shown in Table 1 above, Examples 1 to 9 had high flame retardancy, low dielectric properties, and excellent light resistance. In particular, the hindered amine compound had a high synergistic effect with the NOR type phosphinate compound in terms of flame retardancy, and excellent flame retardancy was obtained. In addition, when zinc phosphinate (Exolit OP950) was used instead of the aluminum phosphinate used in Example 1, a tendency for the same effect as in Example 1 was observed.

[0112] On the other hand, in Comparative Examples 1 to 4, no flame retardant effect was obtained and light resistance was also low unless a hindered amine compound was added, as shown in Table 2. Also, no flame retardant property was obtained unless a phosphinate was added.

[0113] On the other hand, in Comparative Example 5, when the content of the phosphinate was high, the styrene-based composition as a whole did not have flame retardancy as shown in Table 2. This is because dripping during combustion becomes difficult, and the combustion time becomes longer.

[0114] In Comparative Example 6, as shown in Table 2, when a polyphenylene ether-based material was added, high flame retardancy was not obtained, and light resistance decreased. [Industrial Applicability]

[0115] The molded article containing the resin composition of the present invention can be suitably used for computer parts such as desktop computers and notebook computers, mobile phone parts, electric and electronic devices, personal digital assistants, home appliance parts, automobile parts, industrial materials, and sheets, films, foams, etc. for building materials, etc. In particular, it can be suitably used as a component, housing, or housing part of a device that communicates by electromagnetic waves having a frequency of 0.3 to 300 GHz, and can be suitably used for components of transmitter / receivers, mobile phones, tablets, laptops, navigation devices, surveillance cameras, photographic cameras, sensors, diving computers, audio units, remote controls, speakers, headphones, radios, televisions, lighting equipment, home appliances, kitchenware, door openers or gate openers, vehicle central lock operating devices, keyless automobile keys, temperature measuring devices or temperature display devices, measuring devices and control devices, etc.< / gpps> < / hips>

Claims

1. 67.0 to 98.8% by mass of a styrene-based resin (A); A flame retardant (B) containing at least one phosphinate selected from the group consisting of a phosphinate represented by the following general formula (1) and a diphosphinate represented by the following general formula (2), 【Chemistry 1】 [In the above general formula (1), R １１ and R １２ are each independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; M １ is at least one selected from the group consisting of calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion, and protonated nitrogen base; a is M １ represents an ionic valence of 1 to 3; m １ is an integer from 1 to 3; a=m １ It is. １１ and R １２ When there are multiple R １１ and R １２ may be the same or different. 【Chemistry 2】 [In the above general formula (2), R ２１ and R ２２ are each independently a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms; L ２３ is a linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 6 to 10 carbon atoms, or an arylalkylene group having 6 to 10 carbon atoms; M ２ is at least one selected from the group consisting of calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion, and protonated nitrogen base; b is M ２ represents an ionic valence of 1 to 3; m ２ is an integer from 1 to 3; i is an integer of 1 or 2; b×i=2m ２ It is. ２１ and R ２２ When there are multiple R ２１ and R ２２ may be the same or different. and 0.2 to 3.0% by mass of a hindered amine compound (C), The styrene-based resin (A) is a rubber-modified styrene-based resin in which particles of a rubber-like polymer (a) are dispersed in a polymer matrix containing a polystyrene-based polymer, or a styrene-based copolymer resin; The styrene-based copolymer resin has a styrene-based monomer unit, and an unsaturated carboxylic acid-based monomer unit and / or an unsaturated carboxylic acid ester-based monomer unit, and when the total content of the styrene-based monomer unit, the unsaturated carboxylic acid-based monomer unit, and the unsaturated carboxylic acid ester-based monomer unit is taken as 100 mass%, the content of the styrene-based monomer unit is 69 to 98 mass%, and the average particle size of the phosphinic acid salt is 1.5 μm to 20 μm.

2. 2. The flame-retardant styrene-based resin composition according to claim 1, wherein the hindered amine compound (C) is a NOR-type hindered amine compound. Add composition ratio

3. The flame-retardant styrene-based resin composition according to claim 1, wherein the styrene-based copolymer resin has a styrene-based monomer unit and an unsaturated carboxylic acid-based monomer unit and / or an unsaturated carboxylic acid ester-based monomer unit, and when the total content of the styrene-based monomer units, the unsaturated carboxylic acid-based monomer units, and the unsaturated carboxylic acid ester-based monomer units is 100 mass%, the content of the styrene-based monomer units is 74 to 96 mass%.

4. The flame-retardant styrene-based resin composition according to claim 1, wherein the average particle size of the particles of the rubber-like polymer (a) is 0.5 to 4.0 μm.

5. A flame-retardant styrene-based resin composition as described in claim 1, wherein the content of rubber-like polymer contained in the rubber-modified styrene-based resin is 3 to 20 mass% relative to 100 mass% of the rubber-modified styrene-based resin.

6. A molded article comprising the flame-retardant styrene-based resin composition according to claim 1 .

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