JP7219645B2 - Flame-retardant styrene resin composition, molded article, and extruded sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to flame-retardant styrenic resin compositions, molded articles, and extruded sheets.

Styrene-based resins are used in a wide range of applications due to their excellent moldability, dimensional stability, and impact resistance. Among them, flame-retardant polystyrene-based resin compositions are used in a wide variety of applications, including home appliances and OA equipment, and there is currently a demand for thinner products from the viewpoint of reduction and weight reduction.
Conventionally, various flame retardants have been proposed for imparting flame retardancy to styrenic resins, and among them, bromine-based flame retardants, which are inexpensive and have an excellent balance of physical properties, are often used. However, in recent years, the movement to regulate halogen-containing organic compounds has become active mainly in Europe, and the demand for flame-retardant resins and flame-retardant resin compositions containing no bromine element is increasing.

Japanese Patent Publication No. 2002-507238

As an alternative flame retardant to such a bromine-based flame retardant, for example, Patent Document 1 discloses a technique of adding a specific NOR-type hindered amine compound. Regarding polystyrene to which a NOR-type hindered amine compound is added, although there is a description that it exhibits flame retardancy and finds application in housings for office equipment (Example 16), 0.125 inch (about 3.2 mm) However, it is difficult to apply it to thin housings, sheets, and films for office equipment and home appliances that require high flame resistance. In Example 15, a specific NOR-type hindered amine compound was added to ABS, which is a styrenic resin generally effective for flame retardancy. No improvement in performance was observed, indicating that existing bromine-based flame retardants are necessary. In addition, in Patent Document 1, it was merely performed on a general rubber-modified polystyrene resin, and styrene monomer units, unsaturated carboxylic acid monomer units, and unsaturated carboxylic acid ester units were used. There is no disclosure whatsoever about the effectiveness of flame retardancy when a copolymer resin containing a monomer unit or a maleic anhydride-modified ethylene-α-olefin copolymer is used with a NOR type hindered amine compound.

Therefore, with the above-described prior art, it is not possible to obtain a resin composition that exhibits sufficient flame retardancy even in products with a wall thickness of less than 0.125 inches. Even if it is used in combination, it is necessary to add a large amount, which lowers heat resistance and impact resistance, making it difficult to commercialize.

Accordingly, an object of the present invention is to provide a flame-retardant styrene-based resin composition that exhibits high flame-retardancy even in thin-wall molding and has excellent heat resistance, impact resistance, and moldability, and the flame-retardant styrene-based resin composition. It is to provide a molded article containing the flame-retardant styrene resin composition and an extruded sheet formed using the flame-retardant styrene resin composition.

As a result of intensive studies in order to solve the above problems, the present inventors have found that a copolymer containing a styrene-based monomer unit, an unsaturated carboxylic acid-based monomer unit, and an unsaturated carboxylic acid ester-based monomer unit By containing a resin, a maleic anhydride-modified ethylene-α-olefin copolymer, and a NOR-type hindered amine compound in specific proportions, it surprisingly exhibits extremely high flame retardancy, heat resistance, and impact resistance. The inventors have found that a flame-retardant styrenic resin composition having high strength and good moldability can be obtained, and have completed the present invention.

That is, the present invention is as follows.
[1] (A) 86.5 to 99.3 mass% of a copolymer resin containing styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units, (B) 0.5 to 10.0% by mass of maleic anhydride-modified ethylene-α-olefin copolymer and (C) 0.2 to 3.5% by mass of NOR type hindered amine compound. A flame-retardant styrenic resin composition.
[2] The copolymer resin (A) has a total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units of 100% by mass. When containing 67.0 to 96.0% by mass of the styrene-based monomer unit, and containing 4.0 to 18.0% by mass of the unsaturated carboxylic acid-based monomer unit, and The flame-retardant styrenic resin composition according to [1], containing 0.0 to 15.0% by mass of unsaturated carboxylic acid ester-based monomer units.
[3] The above [1] or [2], wherein the maleic anhydride-modified ethylene-α-olefin copolymer (B) has a maleic anhydride grafting ratio of 0.5 to 2.0% by mass. A flame-retardant styrenic resin composition.
[4] Furthermore, (D) one or more flame retardants selected from the group consisting of phosphorus-based flame retardants and bromine-based flame retardants are added in the total amount of the components (A), (B), and (C). The flame-retardant styrene resin composition according to any one of [1] to [3], containing 1.0 to 10.0 parts by mass per 100 parts by mass.
[5] A molded article containing the flame-retardant styrene resin composition according to any one of [1] to [4].
[6] A non-foamed extruded sheet formed using the flame-retardant styrene resin composition according to any one of [1] to [4].
[7] A foam extruded sheet formed using the flame-retardant styrene resin composition according to any one of [1] to [4].

INDUSTRIAL APPLICABILITY According to the present invention, a flame-retardant styrene resin composition that exhibits high flame retardancy even in thin-wall molding and has excellent heat resistance, impact resistance, and moldability, and molding containing the flame-retardant styrene resin composition and an extruded sheet formed using the flame-retardant styrenic resin composition.

Hereinafter, embodiments of the present invention (hereinafter referred to as "present embodiments") will be described in detail. can be implemented.

[Flame-retardant styrene resin composition]
The flame-retardant styrenic resin composition of the present embodiment includes (A) a copolymer containing a styrene-based monomer unit, an unsaturated carboxylic acid-based monomer unit, and an unsaturated carboxylic acid ester-based monomer unit 86.5 to 99.3% by mass of resin, (B) 0.5 to 10% by mass of maleic anhydride-modified ethylene-α-olefin copolymer, and (C) 0.2 to 3.5% by mass of NOR type hindered amine compound Contains % by mass. The flame-retardant styrene-based resin composition of the present embodiment exhibits high flame retardancy even in thin-wall molding, and is excellent in heat resistance, impact resistance, and moldability.
Hereinafter, the flame-retardant styrene resin composition is referred to as a resin composition, and (A) a styrene monomer unit, an unsaturated carboxylic acid monomer unit, and an unsaturated carboxylic acid ester monomer unit. Copolymer resin (A) copolymer resin or (A) component, (B) maleic anhydride-modified ethylene-α-olefin copolymer (B) copolymer or (B) component, (C) NOR type hindered amine A system compound is also called a (C) component.

<(A) Copolymer resin>
In the present embodiment, the content of (A) copolymer resin containing styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units is (A) When the total mass of the copolymer resin, (B) the copolymer, and (C) the NOR-type hindered amine compound is 100% by mass, it is 86.5 to 99.3% by mass, preferably 90.0 to 98.0% by mass. 0% by mass, more preferably 93.0 to 97.0% by mass. By setting the content to 86.5% by mass or more, heat resistance can be improved. On the other hand, by setting the content to 99.3% by mass or less, the total content of (B) the copolymer and (C) the NOR-type hindered amine compound can be secured, and impact strength and the like can be improved. be able to.

In the copolymer resin (A), 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 100% by mass, The content of styrenic monomer units is preferably 67.0 to 96.0% by mass, more preferably 74.0 to 92.0% by mass, and still more preferably 77.0 to 87.0% by mass. It is in the range of % by mass. By making the content 67.0% by mass or more, the fluidity of the resin can be improved, while by making the content 96.0% by mass or less, the unsaturated carboxylic acid-based Desired amounts of monomer units and unsaturated carboxylic acid ester-based monomer units are present, and the below-described effects of these monomer units are exhibited.

In the resin composition of the present embodiment, the unsaturated carboxylic acid-based monomer unit plays a role of improving heat resistance. (A) When the total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units in the copolymer resin is 100% by mass, unsaturated carboxylic acid The content of acid-based monomer units is preferably 4.0 to 18.0% by mass, more preferably 6.0 to 16.0% by mass, and still more preferably 8.0 to 13.0% by mass. % by mass. By setting the content to 4.0% by mass or more, heat resistance can be further improved, while by setting the content to 18.0% by mass or less, high flame retardancy can be exhibited. Also, the fluidity and mechanical properties of the resin can be improved.

In general, styrene-methacrylic acid-based resins including styrene-methacrylic acid-methyl methacrylate copolymer resins are produced by radical polymerization in most cases on an industrial scale. Therefore, in some cases, various alcohols are added to the polymerization system to carry out the polymerization.

In the present embodiment, the unsaturated carboxylic acid ester-based monomer suppresses the dehydration reaction of the unsaturated carboxylic acid-based monomer through intermolecular interaction with the unsaturated carboxylic acid-based monomer, and It can be used to improve the mechanical strength of the resin. Furthermore, the unsaturated carboxylic acid ester monomer contributes to the improvement of resin properties such as weather resistance and surface hardness.
When the total content of styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units is 100% by mass, unsaturated carboxylic acid ester-based monomer units The content of is preferably 0.0 to 15.0% by mass, more preferably 1.0 to 12.0% by mass, still more preferably 2.0 to 10.0% by mass. By setting the content to 15.0% by mass or less, the fluidity of the resin can be improved and the water absorption can be suppressed. Further, by setting the content of the unsaturated carboxylic acid ester-based monomer unit to 0.0% by mass, it is possible to improve heat resistance and reduce costs. The content of monomeric units can also be greater than 0.0% by mass.

When an unsaturated carboxylic acid-based monomer and an unsaturated carboxylic acid ester-based monomer unit are bonded side by side, if a high-temperature, high-vacuum devolatilization apparatus is used, a dealcoholization reaction may occur depending on the conditions. Six-membered cyclic anhydrides may be formed. The (A) copolymer resin of the present embodiment may contain this six-membered cyclic acid anhydride, but it is preferable that the amount is less because it lowers the fluidity.

In the present embodiment, the content of styrene monomer units, methacrylic acid monomer units and methyl methacrylate monomer units in the copolymer resin (A) is determined by proton nuclear magnetic resonance ( ¹ H-NMR ) can be obtained from the integral ratio of the spectrum measured by the measuring instrument. The content of each monomer unit in the copolymer resin (A), which will be described later, can also be similarly determined by proton nuclear magnetic resonance measurement.

In the present embodiment, the copolymer resin (A) contains monomer units other than styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units. Although it is not excluded to further contain within the range that does not impair the effect of the invention, typically, styrene-based monomer units, unsaturated carboxylic acid-based monomer units, and unsaturated carboxylic acid ester-based monomer units consists of

Examples of styrene-based monomers include, but are not limited to, styrene, α-methylstyrene, α-methyl-p-methylstyrene, ο-methylstyrene, m-methylstyrene, p-methylstyrene, and vinyltoluene. , ethylstyrene, isobutylstyrene, t-butylstyrene, bromostyrene, chlorostyrene, and indene. As the styrene-based monomer, styrene is preferable from an industrial point of view. These styrenic monomers can be used singly or in combination of two or more.

Examples of unsaturated carboxylic acid-based monomers include, but are not particularly limited to, methacrylic acid, acrylic acid, maleic anhydride, maleic acid, fumaric acid, and itaconic acid. As the unsaturated carboxylic acid-based monomer, methacrylic acid is preferable because it has a large effect of improving heat resistance and is liquid at room temperature and excellent in handleability. These unsaturated carboxylic acid-based monomers can be used singly or in combination of two or more.

Furthermore, the unsaturated carboxylic acid ester monomer is not particularly limited, but examples include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) ) cyclohexyl acrylate and the like. As the (meth)acrylic acid ester-based monomer, methyl (meth)acrylate is preferable because it has little effect on deterioration of heat resistance. These unsaturated carboxylic acid ester monomers can be used singly or in combination of two or more.

In the present embodiment, the weight average molecular weight (Mw) of (A) the copolymer resin is preferably 100,000 to 350,000, more preferably 120,000 to 300,000, still more preferably 140,000 to 240,000. When the weight-average molecular weight (Mw) is from 100,000 to 350,000, a resin having excellent balance between mechanical strength and fluidity can be obtained, and gel matter is less mixed. The weight average molecular weight (Mw) is a value obtained by standard polystyrene conversion using gel permeation chromatography.

In the present embodiment, the melt flow rate of the copolymer resin (A) is preferably 0.3 to 3.0 g/10 min, more preferably 0.4 to 2.5 g/10 min, still more preferably 0.4 to 2.0 g/10 min. A melt flow rate of 0.3 g/10 min or more is preferred from the viewpoint of fluidity, and a melt flow rate of 3.0 g/10 min or less is preferred from the viewpoint of mechanical strength of the resin. The melt flow rate is a value measured at 200° C. and a load of 49 N in accordance with ISO 1133.

In the present embodiment, the method for polymerizing the copolymer resin (A) is not particularly limited, but for example, a bulk polymerization method or a solution polymerization method can be suitably employed as a radical polymerization method. The polymerization method mainly includes a polymerization step of polymerizing raw materials for polymerization (monomer components) and a devolatilization step of removing volatile matter such as unreacted monomers and polymerization solvent from the polymerization product.
The method for polymerizing the copolymer resin (A) that can be used in the present embodiment will be described below.

(A) When the raw materials for polymerization are polymerized to obtain a copolymer resin, the raw material composition for polymerization is typically made to contain a polymerization initiator and a chain transfer agent. Examples of polymerization initiators include organic peroxides such as 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)cyclohexane, n-butyl-4,4-bis(t -Butylperoxy)valerate and other peroxyketals, dialkylperoxides such as di-t-butylperoxide, t-butylcumylperoxide and dicumylperoxide, diacylperoxides such as acetylperoxide and isobutyrylperoxide, diisopropylperoxydi Examples include peroxydicarbonates such as carbonates, peroxyesters such as t-butylperoxyacetate, 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.

Examples of chain transfer agents include α-methylstyrene linear dimer, n-dodecylmercaptan, t-dodecylmercaptan, n-octylmercaptan and the like.

As a polymerization method, solution polymerization using a polymerization solvent can be employed as necessary. Examples of the polymerization solvent to be used include aromatic hydrocarbons such as ethylbenzene and dialkyl ketones such as methyl ethyl ketone, each of which may be used alone or in combination of two or more. Other polymerization solvents such as aliphatic hydrocarbons can be further mixed with the aromatic hydrocarbons as long as they do not reduce the solubility of the polymerization product. These polymerization solvents are preferably used in an amount not exceeding 25 parts by mass with respect to 100 parts by mass of the total monomers. If the amount of the polymerization solvent exceeds 25 parts by mass with respect to 100 parts by mass of the total monomers, the polymerization rate tends to decrease significantly and the mechanical strength of the resulting resin tends to decrease significantly. Addition of 5 to 20 parts by mass per 100 parts by mass of all monomers prior to polymerization facilitates homogenization of quality and is also preferable from the viewpoint of polymerization temperature control.

In the present embodiment, the apparatus used in the polymerization step for obtaining the (A) copolymer resin is not particularly limited, and may be appropriately selected according to the polymerization method of the styrene-based resin. For example, in the case of bulk polymerization, a polymerization apparatus in which one or a plurality of complete mixing reactors are connected can be used. The devolatilization step is not particularly limited, and in the case of bulk polymerization, the polymerization is continued until the final unreacted monomer is preferably 50% by mass or less, more preferably 40% by mass or less. In order to remove volatile matter such as, devolatilization treatment is performed by a known method. For example, ordinary devolatilizers such as flash drums, twin-screw devolatilizers, thin film evaporators and extruders can be used, but devolatilizers with a small stagnant portion are preferred. The temperature of the devolatilization treatment is usually about 190 to 280° C., and more preferably 190 to 260° C. from the viewpoint of suppressing the formation of a six-membered cyclic acid anhydride due to the adjacency of methacrylic acid and methyl methacrylate. . The pressure of the devolatilization treatment is usually about 0.13 to 4.0 kPa, preferably 0.13 to 3.0 kPa, more preferably 0.13 to 2.0 kPa. Desirable devolatilization methods include, for example, a method of reducing the pressure under heating to remove the volatile matter, and a method of removing the volatile matter through an extruder or the like designed for the purpose of removing the volatile matter.

<(B) Maleic anhydride-modified ethylene-α-olefin copolymer>
In this embodiment, the flame-retardant styrenic resin composition contains (B) a maleic anhydride-modified ethylene-α-olefin copolymer. The (B) maleic anhydride-modified ethylene-α-olefin copolymer is obtained by graft-modifying an ethylene-α-olefin copolymer with maleic anhydride.
The (B) copolymer is such that the maleic anhydride portion in the (B) copolymer is easily compatible with the (A) copolymer resin, and the (A) copolymer resin is finely dispersed to provide rigidity. The impact strength can be improved with little decrease, and the orientation of the (B) copolymer can be suppressed even for foamed or non-foamed extruded sheets, so the impact strength can be improved. In addition, since the maleic anhydride portion in the (B) copolymer interacts with the methacrylic acid portion of the (A) copolymer resin, the gelation of the (A) copolymer resin is suppressed, and foaming and non-foaming extrusion are performed. Sheet impact strength can be improved. Furthermore, since the (B) copolymer has an ethylene-α-olefin portion that is difficult to be compatible with the (A) copolymer resin, the heat resistance of the (A) copolymer resin having heat resistance is hardly affected, The heat resistance of the composition as a whole can be ensured, and it is effective in imparting flame retardancy to the NOR-type hindered amine compound.

In the present embodiment, the content of (B) the maleic anhydride-modified ethylene-α-olefin copolymer is 0.5 to 10.0% by mass with respect to 100% by mass of the flame-retardant styrene resin composition. Yes, preferably 1.0 to 8.0% by mass, more preferably 2.0 to 6.0% by mass.

By setting the content to 0.5% by mass or more, the impact strength and the sheet impact of foamed or non-foamed extrusion can be improved. On the other hand, by setting the content to 10.0% by mass or less, rigidity can be improved. In addition, if the content is too large, a large amount of the copolymer (B) in the resin composition tends to be present in the surface layer, and there is a risk that the heat resistance in the surface layer is likely to decrease, or foaming, non-foaming extrusion On the other hand, the (B) copolymer tends to be oriented, and there is a possibility that the sheet impact strength is lowered. However, by setting the content to 10.0% by mass or less, heat resistance, impact strength, and foamed/non-foamed extrusion sheet impact strength are not lowered.

By finely dispersing (B) the maleic anhydride-modified ethylene-α-olefin copolymer in the (A) copolymer resin, it is possible to improve the impact resistance without significantly lowering the heat resistance. It is also effective in preventing gelation of the copolymer resin (A), and is effective in improving appearance and moldability. From the viewpoint of heat resistance, impact resistance, appearance, and moldability, the maleic anhydride grafting ratio of (B) the maleic anhydride-modified ethylene-α-olefin copolymer is particularly When the content of the α-olefin copolymer is 100% by mass, it is preferably 0.5 to 2.0% by mass, more preferably 0.5 to 1.5% by mass. If maleic anhydride is not grafted, it cannot be finely dispersed in the copolymer resin (A) and the impact strength cannot be improved. end up

(B) The ethylene-α-olefin copolymer of the maleic anhydride-modified ethylene-α-olefin copolymer is not particularly limited, but examples thereof include ethylene and those having 3 to 20 carbon atoms, more preferably those having 3 to 20 carbon atoms. Ethylene-α-olefin copolymer rubbers composed of α-olefins of 6 to 12 can be mentioned. Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1- dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1- Pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene and combinations thereof. Among them, hexene, 4-methylpentene and octene are preferred, and octene-1 is particularly preferred. These are more preferably produced with known metallocene-based catalysts or Ziegler-based catalysts, and most preferably produced with metallocene-based catalysts. 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1, 5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8- decatriene (DMDT), dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropene-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene Polyenes of conjugated dienes may be copolymerized.

In the present embodiment, the method for producing (B) the maleic anhydride-modified ethylene-α-olefin copolymer is not particularly limited, and a known method can be used. It is possible to use a melt modification method of melting and adding maleic anhydride as a graft monomer to carry out graft copolymerization, or a solution modification method of dissolving in a solvent, adding a graft monomer and carrying out graft copolymerization, or the like.

<(C) NOR Hindered Amine Compound>
(C) The content of the NOR-type hindered amine compound is 0.2 to 3.5% by mass, preferably 0.2 to 3.5% by mass, based on 100% by mass of the total amount of components (A) and (B). It is 3.0% by mass, more preferably 0.5 to 2.5% by mass, and even more preferably 1.0 to 2.0% by mass. If it is 0.2% by mass or more, flame retardancy can be obtained with a thin and thick molded product. Moreover, even if it is added in excess of 3.5% by mass, no improvement in flame retardancy is observed, and impact resistance, heat resistance, and foaming properties are greatly reduced.
The (C) NOR-type hindered amine compound is well known as a light stabilizer, and can impart light resistance by adding it.

(C) The alkoxyimino group of the NOR (alkoxyimino group) type hindered amine compound is an NH type in which the imino group (>N—H) portion of the piperidine ring remains NH, and H is a methyl group. In contrast to the substituted N-methyl type, it has an N-alkoxyl group (>N-OR) structure, and the N-alkoxyl group easily becomes a radical by capturing an alkylperoxy radical (RO _2. ). Demonstrate flame retardant effect. On the other hand, in the case of N-methyl hindered amine compounds or NH hindered amine compounds, the flame retardancy may be lower than in the case of NOR hindered amine compounds.

The above alkoxyl group (-OR) is not limited to an alkoxyl group in which oxygen is bonded to an alkyl group, and R includes a cycloalkyl group, an aralkyl group, an aryl group, etc., in addition to the alkyl group.
Specific examples of these alkoxyl groups are preferably a methoxy group, a propoxy group, a cyclohexyloxy group and an octyloxy group. It is preferable from the viewpoint that bleeding out from the film can be suppressed.

The (C) NOR-type hindered amine compound used in the present embodiment is not particularly limited as long as it has a structure of an N-alkoxyl group (>N-OR). Specific examples include NOR-type hindered amine compounds described in JP-A-2002-507238, WO 2005/082852, WO 2008/003605, and the like.

Further, the (C) NOR-type hindered amine-based compound is particularly preferably of a polymer type. Macromolecular types are generally oligomeric or polymeric compounds. If it is a polymer type, mold deposits during molding can be reduced, and it is excellent in terms of flame retardancy and heat resistance.
The number of repeating units of the polymer type oligomeric or polymeric compound is preferably 2 to 100, more preferably 5 to 80.

Specific examples of NOR-type hindered amine compounds include the following compounds: 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine; bis(1-octyloxy-2,2 ,6,6-tetramethylpiperidin-4-yl) 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; 4,4′-hexamethylenebis(amino-2,2 ,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-octyloxy-2, Oligomeric compounds which are condensation products with 2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine; 4,4′-hexamethylenebis(amino-2,2,6,6 -tetramethylpiperidine) and 2,4-dichloro-6-[(1-cyclohexyloxy-2,2,6, Oligomeric compounds which are condensation products with 6-tetramethylpiperidin-4-yl)butylamino]-s-triazine; 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidine -4-yl)-6-chloro-s-triazine; peroxide-treated 4-butylamino-2,2,6,6-tetramethylpiperidine, 2,4,6-trichloro-s-triazine, and cyclohexane and the reaction product of N,N′-ethane-1,2-diylbis(1,3-propanediamine) (N,N′,N′″-tris{2,4-bis[(1-cyclohexyl oxy-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.

Commercially available products include Flamestab NOR116FF, TINUVIN NOR371, TINUVIN XT850FF, TINUVIN XT855FF, TINUVIN PA123 manufactured by BASF, and LA-81 manufactured by ADEKA Corporation.
(C) NOR-type hindered amine compounds may be used singly or in combination of two or more.

<(D) Phosphorus Flame Retardant, Bromine Flame Retardant>
The flame-retardant styrene-based resin composition of the present embodiment may contain (D) one or more flame retardants selected from the group consisting of phosphorus-based flame retardants and bromine-based flame retardants. When a phosphorus-based flame retardant and/or a bromine-based flame retardant are used, a synergistic effect with (C) the NOR-type hindered amine-based compound makes it possible to obtain even higher flame retardancy.
The phosphorus-based flame retardant and the bromine-based flame retardant may be a single compound or a mixture, and both the phosphorus-based flame retardant and the bromine-based flame retardant may be used.
In addition, hereinafter, one or more flame retardants selected from the group consisting of (D) phosphorus-based flame retardants and bromine-based flame retardants are also referred to as component (D).

The content of component (D) is preferably 1.0 to 10.0 parts by mass, more preferably 100 parts by mass, based on 100 parts by mass of the total amount of components (A), (B) and (C). is 1.5 to 8.0 parts by mass, more preferably 2.0 to 5.0 parts by mass. If the amount is less than 1.0 parts by mass, the synergistic effect of improving flame retardancy is difficult to see, and if the amount is more than 10.0 parts by mass, impact strength and heat resistance tend to decrease.

-Phosphorus Flame Retardant-
The phosphorus-based flame retardant is not particularly limited, and one obtained by a conventionally known method or a commercially available product can be used. Phosphate ester compounds, phosphazene compounds, or phosphonate ester compounds are preferred, and these may be used alone or in combination of two or more. Among them, (A) a phosphoric acid ester compound or a phosphonic acid ester compound having good compatibility with the copolymer resin is most preferable.

When the phosphorus content of the phosphorus-based flame retardant is 3.0% by mass or more, a synergistic effect of flame retardancy with (C) the NOR-type hindered amine compound is exhibited, and high flame retardancy can be obtained with a small addition amount. You can get sex. A phosphorus content of 3.0% by mass or more means a phosphorus compound containing 3.0% by mass or more of elemental phosphorus in the phosphorus-based flame retardant.
The phosphorus-based flame retardant preferably has a phosphorus content of 3.0% by mass or more, more preferably 7.0% by mass or more. When the phosphorus content is 3.0% by mass or more, a synergistic effect on (C) NOR-type hindered amine compound and flame retardancy is exhibited, so high flame retardancy, that is, UL94 vertical burning test (UL94-V test), V-2 can be obtained at a thickness of 0.8 mm.
In addition, phosphorus content can be measured by an absorptiometric method.

As the phosphorus-based flame retardant, a flame retardant that is liquid at 150° C. to 300° C. and has a melting point of 300° C. or less is preferable because it is well dispersed in the styrene-based resin. If a phosphorus-based flame retardant that is solid during melt-kneading (for example, a phosphorus-based flame retardant that does not have a melting point) is used, the phosphorus-based flame retardant is not liquid during melt-kneading, so components (A) and (B) It may not be uniformly dispersed in the components, resulting in deterioration of physical properties or deterioration of flame retardancy.

--Phosphate compound--
Phosphate ester compounds include, for example, trimethyl phosphate (TMP), triethyl phosphate (TEP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP ), resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), bisphenol A bis-dicresyl phosphate, biphenol bis-diphenyl phosphate, biphenol Examples include aromatic condensed phosphate ester compounds such as bis-dixylenyl phosphate, which are reaction products of phosphorus oxychloride, dihydric phenol compounds and phenol (or alkylphenol).

Among these, triphenyl phosphate (TPP), tricresyl phosphate (TCP), resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), and biphenol bis-diphenyl phosphate are preferred. , biphenol bis-dixylenyl phosphate, more preferably triphenyl phosphate (TPP), resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, still more preferably resorcinol bis-dixylenyl phosphate. be.

式（１）中、Ｒ_１～Ｒ_５は水素原子、炭素数１～１０のアルキル基、炭素数３～２０のシクロアルキル基、炭素数６～２０のアリール基、炭素数１～１０のアルコキシ基、又はハロゲン原子であり、Ｒ_１～Ｒ_５は同一でも異なっていてもよい。ｎは１～３０の整数であり、好ましくは０～１０の整数である。
アルキル基としては、メチル、エチル、プロピル、イソプロピル、ブチル、イソブチル、第２ブチル、第３ブチル、アミル、第３アミル、ヘキシル、２－エチルヘキシル、ｎ－オクチル、ノニル、デシル等が挙げられる。
シクロアルキル基としてはシクロヘキシル等が挙げられる。
アリール基としては、フェニル、クレジル、キシリル、２，６－キシリル、２，４，６－トリメチルフェニル、ブチルフェニル、ノニルフェニル等が挙げられる。
アルコキシ基としては、メトキシ、エトキシ、プロポキシ、ブトキシ等が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子等が挙げられる。 In addition, the phosphate ester compound is preferably a condensed phosphate ester compound of the condensation type from the viewpoint of heat resistance, reduction of mold deposits during molding, etc., and is particularly represented by the following formula (1). An aromatic condensed phosphate compound is preferred.

In formula (1), R ₁ to R ₅ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. group, or a halogen atom, and R ₁ to R ₅ may be the same or different. n is an integer of 1-30, preferably an integer of 0-10.
Alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl, amyl, tertiary amyl, hexyl, 2-ethylhexyl, n-octyl, nonyl, decyl and the like.
Cycloalkyl groups include cyclohexyl and the like.
Aryl groups include phenyl, cresyl, xylyl, 2,6-xylyl, 2,4,6-trimethylphenyl, butylphenyl, nonylphenyl and the like.
Alkoxy groups include methoxy, ethoxy, propoxy, butoxy and the like.
A fluorine atom, a chlorine atom, a bromine atom etc. are mentioned as a halogen atom.

Further, among the above phosphate ester compounds, as the phosphorus-based flame retardant of the component (D), from the viewpoint of achieving both flame retardancy and transparency, the following compound No. 1 can be used. Phosphate ester compounds of 1, 2, or 3 are preferred, compound no. 2 or 3 is more preferred, and compound No. 2 is more preferred.
compound no. 2 (resorcinol bis-dixylenyl phosphate), for example, PX-200 from Daihachi Chemical Industry Co., Ltd. is compound No. 2; As 3 (resorcinol bis-diphenyl phosphate), for example, CR-733S manufactured by Daihachi Chemical Industry Co., Ltd. can be used.

-Phosphazene compound-
Examples of phosphazene compounds include 1,1,3,3,5,5-hexa(methoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(ethoxy)cyclotriphosphazene, 1,1 ,3,3,5,5-hexa(n-propoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(iso-propoxy)cyclotriphosphazene, 1,1,3,3,5 ,5-hexa(n-butoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(iso-butoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(phenoxy) ) cyclotriphosphazene, 1,1,3,3,5,5-hexa(p-tolyloxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(m-tolyloxy)cyclotriphosphazene, 1 , 1,3,3,5,5-hexa(o-tolyloxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(4-ethylphenoxy)cyclotriphosphazene, 1,1,3, 3,5,5-hexa(4-n-propylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(4-iso-propylphenoxy)cyclotriphosphazene, 1,1,3, 3,5,5-hexa(4-t-butylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(4-t-octylphenoxy)cyclotriphosphazene, 1,1,3, 3,5,5-hexa(2,3-dimethylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(2,4-dimethylphenoxy)cyclotriphosphazene, 1,1,3, 3,5,5-hexa(2,5-dimethylphenoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(2,6-dimethylphenoxy)cyclotriphosphazene, 1,3,5- Tris(methoxy)-1,3,5-tris(phenoxy)cyclotriphosphazene, 1,3,5-tris(ethoxy)-1,3,5-tris(phenoxy)cyclotriphosphazene, 1,3,5- tris(n-propoxy)-1,3,5-tris(phenoxy)cyclotriphosphazene, 1,3,5-tris(iso-propoxy)-1,3,5-tris(phenoxy)cyclotriphosphazene, 1, 3,5-tris(n-butoxy)-1,3,5-tris(phenoxy)cyclotriphosphazene, 1,3,5-tris(iso-butoxy)-1,3, 5-tris(phenoxy)cyclotriphosphazene, 1,3,5-tris(methoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(methoxy)-1, 3,5-tris(m-tolyloxy)cyclotriphosphazene, 1,3,5-tris(methoxy)-1,3,5-tris(o-tolyloxy)cyclotriphosphazene, 1,3,5-tris(ethoxy )-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(ethoxy)-1,3,5-tris(m-tolyloxy)cyclotriphosphazene, 1,3,5 -tris(ethoxy)-1,3,5-tris(o-tolyloxy)cyclotriphosphazene, 1,3,5-tris(n-propoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene , 1,3,5-tris(n-propoxy)-1,3,5-tris(m-tolyloxy)cyclotriphosphazene, 1,3,5-tris(n-propoxy)-1,3,5-tris (o-tolyloxy)cyclotriphosphazene, 1,3,5-tris(iso-propoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(n-butoxy) -1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(iso-butoxy)-1,3,5-tris(p-tolyloxy)cyclotriphosphazene, 1,3, 5-tris(methoxy)-1,3,5-tris(4-t-butylphenoxy)cyclotriphosphazene, 1,3,5-tris(methoxy)-1,3,5-tris(4-t-octyl phenoxy)cyclotriphosphazene, 1,3,5-tris(n-propoxy)-1,3,5-tris(4-t-butylphenoxy)cyclotriphosphazene, 1,3,5-tris(n-propoxy) -1,3,5-tris(4-t-octylphenoxy)cyclotriphosphazene and the like.

Among these, preferably 1,1,3,3,5,5-hexa(methoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(ethoxy)cyclotriphosphazene, 1,1,3 , 3,5,5-hexa(phenoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(p-tolyloxy)cyclotriphosphazene, 1,3,5-tris(methoxy)-1, 3,5-tris(phenoxy)cyclotriphosphazene, 1,3,5-tris(ethoxy)-1,3,5-tris(phenoxy)cyclotriphosphazene, more preferably 1,1,3,3 ,5,5-hexa(ethoxy)cyclotriphosphazene, 1,1,3,3,5,5-hexa(phenoxy)cyclotriphosphazene, 1,3,5-tris(ethoxy)-1,3,5- Tris(phenoxy)cyclotriphosphazene, more preferably 1,1,3,3,5,5-hexa(phenoxy)cyclotriphosphazene.

式（２）中、Ｒ^１～Ｒ^５は、水素原子、又は置換基を有していてもよい炭化水素基であり、Ｒ^１～Ｒ^５はそれぞれ同一でも異なっていてもよい。
炭化水素基としては、鎖状（直鎖及び分岐鎖のいずれでもよい）及び環状（単環、縮合多環、架橋環及びスピロ環のいずれでもよい）のいずれであってもよく、例えば、側鎖を有する環状炭化水素基が挙げられる。また、炭化水素基は、飽和及び不飽和のいずれでもよい。
炭化水素基としては、例えば、アルキル基、シクロアルキル基、アリル基、アリール基、アルキルアリール基、アリールアルキル基等が挙げられる。 -Phosphonic acid ester-
Phosphonate esters include, for example, those represented by the following formula (2).

In formula (2), R ¹ to R ⁵ are hydrogen atoms or optionally substituted hydrocarbon groups, and R ¹ to R ⁵ may be the same or different.
The hydrocarbon group may be either chain (either linear or branched) or cyclic (either monocyclic, condensed polycyclic, bridged or spirocyclic). A cyclic hydrocarbon group having a chain is mentioned. Also, the hydrocarbon group may be either saturated or unsaturated.
Examples of hydrocarbon groups include alkyl groups, cycloalkyl groups, allyl groups, aryl groups, alkylaryl groups, and arylalkyl groups.

Specific examples of the phosphonate represented by formula (2) include compounds represented by formulas (2)-1 to (2)-8 below.

- Bromine Flame Retardant -
In the present embodiment, the brominated flame retardant can be any brominated flame retardant (brominated flame retardant) that is commonly used in this field without limitation. brominated bisphenol Ss, brominated phenyl ethers, brominated bisphenol A carbonate oligomers, brominated bisphenol A epoxy resins, brominated styrenes, brominated phthalimides, brominated benzenes, brominated cycloalkanes and brominated isocyanurates. These bromine-based flame retardants may be used singly or in combination of two or more.

Brominated bisphenol A compounds or brominated bisphenol S compounds include compounds in which 1 to 8 bromine atoms are bonded to the benzene ring of a bisphenol A residue or bisphenol S residue, examples of which include tetrabrom Bisphenol A, Tetrabromobisphenol A bis(2-hydroxyethyl ether), Tetrabromobisphenol A bis(allyl ether), Tetrabromobisphenol A bis(2-bromoethyl ether), Tetrabromobisphenol A bis(3-bromopropyl ether) ), tetrabromobisphenol A bis(2,3-dibromopropyl ether), tetrabromobisphenol S, tetrabromobisphenol S bis(2-hydroxyethyl ether) and tetrabromobisphenol S bis(2,3-dibromopropyl ether ) etc. can be mentioned.

Commercially available brominated bisphenol A or brominated bisphenol S include "FR-1524" from Brochem Far East Co., Ltd., "Great Lakes BA-50" from Great Lakes Chemical Co., Ltd., " Great Lakes BA-50P", "Great Lakes BA-59", "Great Lakes BA-59P" and "Great Lakes PE-68", Albemarle's "Saytex RB-100", Teijin Kasei Co., Ltd.'s Fireguard 2000", "Fireguard 3000", "Fireguard 3100" and "Fireguard 3600", Marubishi Yuka Kogyo Co., Ltd.'s "Nonen PR-2", Tosoh Corporation's "Frame Cut 121R", "Fire Cut P-680" manufactured by Suzuhiro Kagaku Co., Ltd. can be mentioned.

Brominated phenyl ethers are compounds in which one or more bromine atoms are attached to a phenyl ether group, such as bis(tribromphenoxy)ethane, hexabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether and polydibromphenylene. Oxide etc. can be mentioned.

Commercially available brominated phenyl ether flame retardants include "FR-1210" and "FR-1208" from Bromochem Far East Co., Ltd., and "Great Lakes FF-680" from Great Lakes Chemical Co., Ltd. , Great Lakes DE-83, Great Lakes DE-83R and Great Lakes DE-79, Saytex 102E and Saytex 111 from Albemarle.

で示される基の重合物であって、オリゴマーとは、重合度（ｎ）が１～１０のものをいう。 The brominated bisphenol A-based carbonate oligomer has the following formula (3)

The term "oligomer" refers to a polymer having a degree of polymerization (n) of 1-10.

Examples of the polymer of the group represented by the above formula (3) include flame retardants represented by the following formula (4) or (5).

"Fireguard 7000" and "Fireguard 7500" available from Teijin Kasei Co., Ltd. can be cited as commercially available flame retardants of formula (4).
Examples of commercially available flame retardants of formula (5) include Great Lakes BC-52 and Great Lakes BC-58 available from Great Lakes Chemical Co., Ltd.

Examples of the brominated bisphenol A epoxy resin include compounds represented by the following formula (6).

As the commercially available flame retardant of the above formula (6), there are various products depending on the degree of polymerization (n). F-2400" and "F-2400H", Dainippon Ink and Chemicals Co., Ltd.'s "Platherm EP-16", "Platherm EP-30", "Platherm EP-100" and "Platherm EP-500", Sakamoto Yakuhin Examples include "SR-T1000", "SR-T2000", "SR-T5000" and "SR-T20000" manufactured by Kogyo Co., Ltd.

Further, examples of the brominated bisphenol A epoxy resin include a compound of the above formula (6) in which both terminal epoxy groups are blocked with a blocking agent and a compound in which one terminal epoxy group is blocked with a blocking agent. be able to. The blocking agent is not limited as long as it is a compound capable of ring-opening addition of an epoxy group. Among them, brominated phenols are preferred from the viewpoint of improving the flame retardant effect. be able to.

Examples of the flame retardant in which both terminal epoxy groups of the polymer are blocked with a blocking agent include flame retardants represented by the following formulas (7) and (8).

Commercially available flame retardants of formula (7) or (8) include "Platherm EC-14", "Platherm EC-20" and "Platherm EC-30" manufactured by Dainippon Ink and Chemicals Co., Ltd.; Examples include "TB-60" and "TB-62" manufactured by Kasei Co., Ltd., and "SR-T3040" and "SR-T7040" manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.

Examples of the flame retardant in which only one terminal epoxy group of the polymer is blocked with a blocking agent include flame retardants represented by the following formulas (9) and (10).

Commercially available flame retardants of the above formula (9) or (10) include "Platherm EPC-15F" from Dainippon Ink and Chemicals, Ltd., "E5354" from Yuka Shell Epoxy Co., Ltd., and the like. can be done.

Examples of brominated styrene flame retardants include brominated styrene monomers represented by the following formula (11) in which 1 to 5 bromine atoms are bonded to the benzene ring of the styrene skeleton, and polymers thereof represented by the following formula (12). is preferably a polymer.

Specific examples of brominated styrenes include bromstyrene and brominated polystyrene. Commercially available brominated polystyrene flame retardants include "Great Lakes PDBS" available from Great Lakes Chemical Co., Ltd. -10” and “Great Lakes PDBS-80”. "Pyrocheck 68PB" manufactured by Ferro Co., Ltd. can also be mentioned as an example of a brominated polystyrene-based flame retardant, although the production method is different from that of the flame retardant.

Brominated phthalimide-based flame retardants are compounds in which 1 to 4 bromo atoms are bonded to the benzene ring of the phthalimide group, such as monobromophthalimide, dibromophthalimide, tribromophthalimide, tetrabromophthalimide, ethylenebis (monobromophthalimide), ethylenebis(dibromophthalimide), ethylenebis(tribromophthalimide) and ethylenebis(tetrabromophthalimide) of the following formula (13). Commercially available flame retardants include “Saytex BT-93” and “Saytex BT-93W” from Albemarle.

Brominated benzenes are compounds composed of a group in which one or more bromo atoms are bonded to a benzene ring, such as tetrabromobenzene, pentabromobenzene, hexabromobenzene, bromophenyl allyl ether, pentabromotoluene, bis( Examples include pentabromophenyl)ethane and poly(pentabrombenzyl acrylate), and commercially available flame retardants include “Saytex 8010” from Albemarle.

Brominated cycloalkane systems include brominated hydrocarbons in which from 1 to 6 bromo atoms are attached to cycloalkanes having from 6 to 12 carbon atoms (cycloaliphatic hydrocarbons). Examples of the cycloalkanes include cyclohexane and cyclododecane, and examples of brominated cycloalkanes include pentabromocyclohexane, hexabromocyclohexane, tetrabromocyclododecane, pentabromocyclododecane and hexabromocyclododecane. can be mentioned.
Examples of commercially available hexabromocyclododecane include "FR-1206" from Bromochem Far East Co., Ltd., "Saytex HBCD" from Albemarle Co., Ltd., and "Great Lakes CD-75P" from Great Lakes Chemical Co., Ltd. , Suzuhiro Chemical Co., Ltd. "Fire Cut P-880M" and Daiichi Kogyo Seiyaku Co., Ltd. "Pyroguard SR-103".

Brominated isocyanurates include compounds in which a bromine atom is bonded to an alkyl group having 2 to 6 carbon atoms (chain aliphatic hydrocarbon group) and an isocyanuric acid residue, and 1 to 5 Compounds in which a brominated phenoxy group in which a bromine atom is attached to a phenoxy group and an isocyanuric acid residue are exemplified. Specific examples include tris(monobromopropyl) isocyanurate, tris(2,3-dibromopropyl) isocyanurate, tris(tribromopropyl) isocyanurate, tris(tetrabromopropyl) isocyanurate, tris(pentabrom propyl)isocyanurate, tris(heptabromopropyl)isocyanurate, tris(octabromobutyl)isocyanurate, tris(monobromphenoxy)isocyanurate, tris(dibromophenoxy)isocyanurate, tris(tribromophenoxy)isocyanurate, tris(pentabromphenoxy)isocyanurate, tris(ethylmonobromphenoxy)isocyanurate and tris(propyldibromphenoxy)isocyanurate.
Commercially available brominated isocyanurates include "Taiku-6B" manufactured by Nippon Kasei Co., Ltd. and "Firecut P-660" manufactured by Suzuhiro Chemical Co., Ltd., and the like.

In addition to the widely used bromine-based flame retardants as described above, it is of course possible to use those listed in literature and catalogs of bromine-based flame retardant manufacturers. Brominated flame retardants include brominated phenols, brominated phenoxytriazines, brominated alkanes, brominated maleimides and brominated phthalates.

Brominated phenols are compounds in which 1 to 5 bromo atoms are bonded to a phenol group, such as monobromophenol, dibromophenol, tribromophenol, tetrabromophenol and pentabromophenol. can be done.

Brominated phenoxytriazines are compounds in which 1 to 5 bromo atoms are attached to the phenoxy group and 1 to 3 of the brominated phenoxy groups are attached to the triazine ring, such as mono(tribromophenoxy ) triazine, bis(monobromphenoxy)triazine, bis(tribromophenoxy)triazine, tris(dibromphenoxy)triazine and tris(tribromophenoxy)triazine, etc. Commercially available flame retardants include: Daiichi Kogyo Seiyaku Co., Ltd. "Pyrogard SR-245" can be mentioned.

A brominated alkane is a compound in which a bromine atom is bonded to an alkane having 2 to 6 carbon atoms (chain aliphatic hydrocarbon). Examples of said alkanes include ethane, propane, butane, pentane and hexane, and examples of brominated alkanes are dibromoethane, tetrabromoethane, monobromopropane, tribromopropane, hexabromopropane, octabrome. Propane, tetrabromobutane, hexabromobutane, octabromobutane, tribromopentane, pentabromopentane, octabromopentane, dibromohexane, tribromohexane, tetrabromohexane, hexabromohexane and octabromohexane and the like may be mentioned. can.

Brominated maleimides are compounds in which 1 to 5 bromo atoms are attached to a phenylmaleimide group, such as monobromophenylmaleimide, dibromophenylmaleimide, tribromophenylmaleimide and pentabromophenylmaleimide. be able to.

Bromated phthalates can include compounds having 1 to 4 bromo atoms attached to phthalic anhydride, examples of which include monobromo phthalic anhydride, dibromo phthalic anhydride, tribromo phthalic anhydride and tetrabromo phthalic anhydride. Phthalic acid and the like can be mentioned.

In order to further improve flame retardancy, flame retardant aids such as antimony trioxide are often used in combination. not something to give.
The amount of the flame retardant aid added is usually (A) a copolymer resin 100 containing a styrene-based monomer unit, an unsaturated carboxylic acid-based monomer unit, and an unsaturated carboxylic acid ester-based monomer unit It is used in an amount of 0.5 to 10 parts by mass, but the preferred amount is 1 to 7 parts by mass in terms of physical properties.

<Optional Addition Ingredients>
In addition to the components (A) to (D), the flame-retardant styrenic resin composition of the present embodiment may optionally contain conventionally known additives and processing aids within a range that does not impair the effects of the present invention. Any additional component such as can be added. These additives, processing aids and the like include antioxidants, weathering agents, lubricants, antistatic agents, fillers and the like.

Antioxidants include phenol compounds, phosphorus compounds, thioether compounds and the like.

Phenolic antioxidants include, for example, 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)propionamide], 4,4'-thiobis(6-tert-butyl-m-cresol) , 2,2′-methylenebis(4-methyl-6-tert-butylphenol), 2,2′-methylenebis(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-tert-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)methyl propionate]methane, thiodiethylene glycol bis[(3,5-di-tert-butyl-4-hydroxyphenyl) ) propionate], 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyl 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] and the like.
These may be used in combination of two or more.

Examples of phosphorus antioxidants 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, tridecylphosphite, octyldiphenylphosphite, di(decyl)monophenylphosphite, di(tridecyl)pentaerythritol diphosphite, di(nonylphenyl) ) pentaerythritol diphosphite, bis(2,4-di-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) butane triphosphite, tetrakis (2,4-di-tert-butylphenyl) biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis ( 4,6-tert-butylphenyl)-2-ethylhexylphosphite, 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, phosphites of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol, and the like.
These may be used in combination of two or more.

Examples of thioether antioxidants include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and pentaerythritol tetra(β-alkylmercaptopropionates is mentioned.
These may be used in combination of two or more.

As the weather resistant agent, an ultraviolet absorber, a hindered amine light stabilizer, and the like can be used.

UV absorbers include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5′-methylenebis(2-hydroxy-4-methoxybenzophenone) 2-hydroxybenzophenones such as; 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, 2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)-5-chlorobenzo triazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octyl Phenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-(benzotriazolyl)phenol ), 2-(2′-hydroxyphenyl)benzotriazoles such as 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 - benzoates such as di-tert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanylide and 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano- Cyanoacrylates such as β,β-diphenyl acrylate and methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; 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 in combination of two or more.

Examples of hindered amine light stabilizers 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-butanetetracarboxylate, 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-tetra methyl-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[2,4-bis(N-butyl-N-(1,2,2,6 ,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl]aminoundecane and other hindered amine compounds.
These may be used in combination of two or more.

Fatty acid amides, fatty acid esters, fatty acids, fatty acid metal salts and the like can be used as lubricants.

Examples of aliphatic amide lubricants include stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis stearic acid amide, ethylene bis oleic acid amide, ethylene bis erucic acid amide, and ethylene bis lauric acid amide. be done.
These may be used in combination of two or more.

Aliphatic ester lubricants include methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl oleate, methyl erucate, methyl behenate, butyl laurate, butyl stearate, isopropyl myristate, and palmitic acid. Isopropyl, octyl palmitate, coconut fatty acid octyl ester, octyl stearate, tallow fatty acid octyl ester, lauryl laurate, stearyl stearate, behenyl behenate, cetyl myristate, C28-30 linear, unbranched saturated esters of monocarboxylic acid (hereinafter abbreviated as montanic acid) and ethylene glycol, esters of montanic acid and glycerin, 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, poly Oxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate and the like.
These may be used in combination of two or more.

Specific examples of saturated fatty acids among fatty acid-based lubricants include lauric acid (dodecanoic acid), isodecanoic acid, tridecylic acid, myristic acid (tetradecanoic acid), pentadecic acid, palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid), ), stearic acid (octadecanoic acid), isostearic acid, tubercrostearic acid (nonadecanic acid), 2-hydroxystearic acid, arachidic acid (icosanoic acid), behenic acid (docosanoic acid), lignoceric acid (tetradocosanoic acid), cerotic acid (hexadocosanoic acid), montanic acid (octadocosanoic acid), melissic acid and the like, particularly lauric acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid and montanic acid.
Among fatty acid-based lubricants, unsaturated fatty acids specifically include myristoleic acid (tetradecenoic acid), palmitoleic acid (hexadecenoic acid), oleic acid (cis-9-octadecenoic acid), elaidic acid (trans-9-octadecene 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) and the like.
These may be used in combination of two or more.

Fatty acid metal salt-based lubricants include lithium salts, calcium salts, magnesium salts, and aluminum salts of fatty acids of the above fatty acid-based lubricants.
These may be used in combination of two or more.

Cationic, anionic, nonionic, amphoteric, and fatty acid partial esters such as glycerin fatty acid monoester can be used as antistatic agents.
Specifically, alkyltrimethylammonium salts, dialkyldimethylammonium salts, benzalkonium salts, N,N-bis(2-hydroxyethyl)-N-(3-dodecyloxy-2-hydroxypropyl)methylammonium mesosulphate , (3-laurylamidopropyl)trimethylammonium methylsulfate, stearamidopropyldimethyl-2-hydroxyethylammonium nitrate, stearamidopropyldimethyl-2-hydroxyethylammonium phosphate, cationic polymer, alkylsulfonate , Alkyl benzene sulfonate, Sodium alkyl diphenyl ether disulfonate, Alkyl nitrate ester salt, Phosphate alkyl ester salt, Alkyl phosphate amine salt, Stearate monoglyceride, Pentaerythritol fatty acid ester, Sorbitan monopalmitate, Sorbitan monostearate, Diglycerin 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, hydroxyethylimidazoline sulfate, and the like.
These may be used in combination of two or more.

Talc, calcium carbonate, barium sulfate, carbon fiber, mica, wollastonite, whiskers, and the like can be used as fillers.

In addition, anti-blocking agents, coloring agents, anti-blooming agents, surface treatment agents, antibacterial agents, anti-stain agents (silicone oil described in JP-A-2009-120717, monoamide compounds of higher aliphatic carboxylic acids, and higher fatty acid It is also possible to add a build-up inhibitor such as a monoester compound obtained by reacting a group carboxylic acid with a monohydric to trihydric alcohol compound.

The total content of optional components such as additives and processing aids may be 0.05 to 5% by mass in the flame-retardant styrenic resin composition.

The flame-retardant styrenic resin composition of the present embodiment may consist essentially of components (A) to (C), optional component (D), and optional additive components. In addition, it may be composed of only components (A) to (C), optional component (D), or components (A) to (C), optional component (D), and optional additive components.
"Consisting essentially of (A) to (C) components, optional (D) component, and optional additive components" means 95 to 100 mass% (preferably 98% by mass) of the flame-retardant styrene resin composition. ~ 100% by mass) are (A) components to (C) components, optional (D) components, or (A) components to (C) components, optional (D) components, and optional additive components means that
In addition, the flame-retardant styrene resin composition of the present embodiment includes components (A) to (C), optional component (D), and optional additive components, as long as the effects of the present invention are not impaired. May contain impurities.

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

[Physical properties of flame-retardant styrene resin composition]
<Flame Retardant>
The flame retardancy of the flame-retardant styrene resin composition of the present embodiment is within the standard in the UL94 vertical combustion test (UL94-V test), that is, in the V-0 to V-2 flame retardancy class. Preferably. In addition, in UL94 horizontal combustion (UL94-HB test), it is desirable that the burning rate is 75 mm / min or less, which is within the HB standard, and considering standards such as automobile flame retardant standards (FMVSS302), it is 85 mm / min or less. is preferred.
In the present disclosure, flame retardancy can be evaluated by the method described in the section [Examples] below.

<Charpy impact strength (with notch)>
The flame-retardant styrenic resin composition of the present embodiment preferably has a Charpy impact strength of 1 kJ/m ² or more, more preferably 1.5 kJ/m ² or more. If it is less than 1 kJ/m ² , there is a concern in terms of production such as damage to the extruded sheet during production.
In the present disclosure, Charpy impact strength is a value measured with a notch according to ISO 179.

<Vicat softening temperature>
The Vicat softening temperature of the flame-retardant styrenic resin composition of the present embodiment is preferably 105°C or higher, more preferably 110°C or higher. If it is less than 105°C, the temperature may rise during use and the product may be deformed.
In the present disclosure, the Vicat softening temperature is a value measured under the conditions of a load of 49 N and a heating rate of 50° C./hour in accordance with ISO 306.

[Non-foamed and foamed extruded sheets]
The non-foamed extruded sheet and the foamed extruded sheet of the present embodiment are formed using the heat-resistant styrene resin composition of the embodiment according to the present invention described above. As a method for producing non-foamed and foamed extruded sheets, commonly known methods can be used.
Examples of the method for producing a non-foamed extruded sheet include a method using a short-screw or twin-screw extruder equipped with a T-die and a device for taking up the sheet with a uniaxial stretching machine or a biaxial stretching machine. Examples of the method for producing the sheet include a method using an extrusion foam molding machine equipped with a T-die or a circular die.

In the extruded foam sheet, commonly used substances can be used as the foaming agent and foaming nucleating agent at the time of extrusion foaming. As the foaming agent, butane, pentane, Freon, carbon dioxide, water, etc. can be used, and butane is preferred. Also, talc or the like can be used as a foam nucleating agent.

The extruded foam sheet preferably has a thickness of 0.5 mm to 5.0 mm, an apparent density of 50 g/L to 300 g/L, and a basis weight of 80 g/m ² to 300 g/L. ^m2 is preferred. In addition, the foam extruded sheet is not particularly limited, but for example, it is multi-layered with a styrene resin (polystyrene resin, styrene-butadiene block copolymer, high impact polystyrene (impact resistant polystyrene) made of rubber components such as polybutadiene, etc.). It may be used, or in addition to it, or alternatively, it may be used in a multi-layered manner with a resin other than the styrenic resin. Examples of resins other than styrene resins include, but are not particularly limited to, polypropylene (PP) resins, PP/polystyrene (PS) resins, polyethylene terephthalate (PET) resins, and nylon resins.

On the other hand, the non-foamed extruded sheet preferably has a thickness of, for example, about 0.1 to 1.5 mm from the viewpoint of rigidity and thermoforming cycle. In addition, the non-foamed extruded sheet may be formed only by ordinary roll stretching at a low magnification, but in particular, a sheet stretched by a roll by about 1.3 to 7 times and then by a tenter by about 1.3 to 7 times. is preferable in terms of strength. In addition, the non-foamed extruded sheet is not particularly limited, but for example, it may be used in a multi-layered form with a styrene resin (polystyrene resin, styrene-butadiene block copolymer, high impact polystyrene made of a rubber component such as polybutadiene, etc.), In addition to that, or instead of that, it may be used in a multi-layered manner with a resin other than the styrene-based resin. Examples of resins other than styrene resins include, but are not particularly limited to, PP resins, PP/PS resins, PET resins, nylon resins, and the like.

[Molding]
The molded article of the present embodiment can be produced by the melt-kneading molding machine used for obtaining the flame-retardant styrenic resin composition. Alternatively, the molded article can be produced by injection molding, injection compression molding, extrusion molding, blow molding, press molding, vacuum molding, and foaming using pellets of the obtained flame-retardant styrene resin composition as a raw material. It can be manufactured by a molding method or the like.
Molded articles, preferably injection molded articles (including injection compression), containing the flame-retardant styrenic resin composition of this embodiment can be , information terminals, refrigerators, OA equipment such as microwave ovens, household appliances, housings and various parts of electrical and electronic equipment, foamed heat insulating materials, insulating films, and the like.
Moreover, the molded article of this embodiment may have a portion with a thickness of 0.8 mm or less. Even a molded product having a thickness of 0.8 mm or less exhibits high flame retardancy, and the molded product of the present embodiment can be applied more preferably. It should be noted that the thickness is preferably 0.2 to 0.8 mm.

EXAMPLES The embodiments of the present invention will be described in more detail below based on Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Measurement and evaluation method>
The physical properties of the resin compositions obtained in Examples and Comparative Examples were measured and evaluated according to the following methods.

(1) Contents of styrene monomer units, methacrylic acid monomer units, and methyl methacrylate monomer units in the copolymer resin (A) Measured with a proton nuclear magnetic resonance ( ¹ H-NMR) spectrometer. The resin composition was quantified from the integral ratio of the spectrum.
・Sample preparation: 30 mg of resin pellets were dissolved in 0.75 mL of d ₆ -DMSO by heating at 60° C. for 4 to 6 hours.
・Measurement equipment: JNM ECA-500 manufactured by JEOL Ltd.
・Measurement conditions: measurement temperature 25° C., observation core ¹ H, accumulation times 64 times, repetition time 11 seconds.
(Assignment of spectra)
For spectral assignments measured in dimethylsulfoxide deuterated solvent, the peaks at 0.5-1.5 ppm are the hydrogens of the α-methyl groups of methacrylic acid, methyl methacrylate, and the six-membered cyclic anhydride, 1.6 The peak at ~2.1 ppm is the hydrogen of the methylene group of the polymer main chain, the peak of 3.5 ppm is the hydrogen of the carboxylic acid ester ( _-COOCH3 ) of methyl methacrylate, and the peak of 12.4 ppm is the hydrogen of the carboxylic acid of methacrylic acid. is. Also, the peak at 6.5 to 7.5 ppm is the hydrogen of the aromatic ring of styrene. In addition, since the resins of the present examples and comparative examples have a small content of six-membered cyclic acid anhydride, quantification is usually difficult by this measurement method.

(2) (A) Weight Average Molecular Weight of Copolymer Resin (A) The weight average molecular weight of the copolymer resin was measured under the following conditions and procedures.
- Sample preparation: About 0.05% by mass of resin was dissolved in tetrahydrofuran.
・Measurement conditions Instrument: TOSOH HLC-8220GPC (gel permeation chromatography)
Column: super HZM-H
Temperature: 40°C
Carrier: THF 0.35 mL/min
Detector: RI, UV: 254 nm
Calibration curve: Created using TOSOH standard PS.

(3) Vicat softening temperature Vicat softening temperature (°C) of (A) copolymer resin and resin composition was measured according to ISO 306. The load was 49N, and the temperature increase rate was 50°C/hour.

(4) (A) Melt flow rate (MFR) of copolymer resin
(A) The melt mass flow rate (g/10 minutes) of the copolymer resin was measured according to ISO 1133 (200°C, load 49N).

(5) Flame retardancy Using a test piece (b) (size: 127 mm × 12.7 mm, thickness: 1.5 mm or 0.8 mm) prepared by the method described later, a UL94 vertical burning test with a 50 W test flame ( Flame retardancy was evaluated by a method conforming to UL94-V test).
The flame of a gas burner was applied to the test piece (b) to evaluate the degree of combustion.
The flame retardant grade indicates the flame retardant class classified by the UL94-V test. Five tests were performed on all test pieces, and judgment was made. The outline of the classification method is as follows.
V-0: 5 total burning time of 50 seconds or less, maximum burning time of 10 seconds or less, no dripping cotton ignition V-1: 5 total burning time of 250 seconds or less, maximum burning time of 30 seconds or less, dripping cotton ignition V-2: 5 total burning time 250 seconds or less, maximum burning time 30 seconds or less, with dripping cotton ignition Not V: Non-compliant with UL94 minutes) were measured.

(6) Charpy impact strength The Charpy impact strength (kJ/m ² ) of the test piece (b) prepared by the method described below was measured in accordance with ISO 179 with a notch.

[Non-foaming extrusion properties and non-foaming extrudate properties]
(7) Measurement of impact strength (kgf cm) of non-foamed extruded sheet A film impact tester (A121807502) manufactured by Toyo Seiki Co., Ltd. is applied to a stretched sheet having a thickness of 0.1 mm prepared under predetermined conditions using a resin composition. The impact strength was measured according to ASTM D3420.

[Characteristics of foam extrudate]
(8) Measurement of impact strength (kgf cm) of foamed extruded sheet A foamed sheet produced under predetermined conditions using a resin composition was tested using a film impact tester (A121807502) manufactured by Toyo Seiki Co., Ltd. in accordance with ASTM D3420. , the impact strength was measured.

Each material used in the examples is as follows.

[(A) Copolymer resin]
(Resin (a-1))
71.3 parts by mass of styrene, 7.3 parts by mass of methacrylic acid, 6.4 parts by mass of methyl methacrylate, 15.0 parts by mass of ethylbenzene, and 0.025 parts by mass of 1,1-bis(t-butylperoxy)cyclohexane At a rate of 1.1 liters/hour, a polymerization raw material composition liquid consisting of , to a devolatilization device connected to a single-screw extruder for removing volatile matter such as a polymerization solvent, to prepare a resin. The polymerization reaction conditions in the polymerization process 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 -5° C. refrigerant was passed, and recovered as an unreacted liquid. The polymer content in the final polymerization liquid was measured by the formula [(sample mass after drying / sample mass before drying) x 100%] after drying the polymerization liquid for 30 minutes at 215 ° C. under a reduced pressure of 2.5 kPa. , 65.6% by mass, and the weight average molecular weight was 214,000 (214,000). Table 1 shows the composition ratio, characteristics, etc. of the obtained resin.

(Resins (a-2), (a-3))
The composition, polymerization temperature conditions, etc. were adjusted so that the properties of the resin shown in Table 1 were obtained, and (A) copolymer resin was obtained in the same manner as for resin (a-1).

[(B) Maleic anhydride-modified ethylene-α-olefin copolymer]
(Resin (b-1))
Scona TSPOE 1002 GBLL (maleic anhydride ethylene/octene copolymer, maleic anhydride content 1.5% by mass) manufactured by Big Chemie was used.

(Resin (b-2))
Scona TSPOE 1002 CMB1-2 (maleic anhydride ethylene/octene copolymer, maleic anhydride content 0.55% by mass) manufactured by Big Chemie was used.

[(C) Component]
· NOR type hindered amine compound A (c-1) [manufactured by BASF, Flamestab NOR116FF, polymer type]
· NOR-type hindered amine compound B (c-2) [BASF, TINUVIN PA123]

[(D) component]
・Phosphonate ester compound [Marubishi Yuka Kogyo Co., Ltd., Nonnen 73, melting point 100 ° C., phosphorus content 10% by mass]
· Phosphate ester: resorcinol bis-dixylenyl phosphate [manufactured by Daihachi Chemical Industry Co., Ltd., PX-200, melting point 92 ° C., phosphorus content 9.0% by mass, condensation type]
- Bromine-based flame retardant: bis (pentabromphenyl) ethane [Albemarle Co., Ltd., Saytex8010]

[Additive]
(Phenolic antioxidant)
· 3-(3,5-di-tert-butyl-4-hydroxyphenyl) stearyl propionate [manufactured by BASF, Irganox1076]
(Phosphorus antioxidant)
- Tris (2,4-di-tert-butylphenyl) phosphite [manufactured by BASF, Irgafos168]

[Examples 1 to 13]
0.2 parts by mass of Irganox 1076 and Irgafos 168 were added to 100 parts by mass of each component and components (A) to (C) in the composition ratio shown in Table 2, and then premixed. The resulting preliminary mixture is mixed together and melt-extruded at 180° C. to 230° C. using a twin-screw extruder (TEM-26SS, manufactured by Toshiba Machine Co., Ltd.) to obtain a flame-retardant styrene resin composition as a kneaded product. I got a pellet of stuff. At this time, the screw rotation speed was 150 rpm, and the discharge rate was 10 kg/hr.
Using an injection molding machine manufactured by Japan Steel Works, Ltd. equipped with a pin gate plate mold having dimensions of 127 mm × 12.7 mm × thickness of 1.5 mm or 0.8 mm, the pellets obtained in this way are molded at a cylinder temperature of 220 ° C. Mold temperature 50 ° C., injection pressure (gauge pressure 40 to 60 MPa), injection speed (panel set value) 50%, injection time / cooling time = 5 sec / 20 sec to prepare a test piece (b), each physical property was measured and evaluated. Table 2 shows the results.

Furthermore, using the obtained resin pellets, a non-foamed extruded product (non-foamed extruded sheet) and a foamed extruded product (a foamed extruded sheet and a tray container as a molded product) are produced, and the physical properties are evaluated by the above methods. bottom.
For the non-foamed extruded sheet, a 25 mm diameter single screw sheet extruder manufactured by Soken Co., Ltd. was used to set the temperature of the resin melting zone to 220 to 230° C., and a sheet having a thickness of about 0.7 mm was produced. Further, this sheet was heated at 140° C. for 10 minutes with a biaxial stretching apparatus EX6-S1 manufactured by Toyo Seiki Co., Ltd., and then stretched 5 times in the extrusion direction of the sheet and 1.5 times in the direction perpendicular to the extrusion of the sheet to give a stretch of about 0.5. A sheet of 1 mm was produced.
The extruded foam sheet is produced by compressing a sheet with a thickness of about 0.18 mm and impregnating it with liquefied carbon dioxide gas at 10 mPa for 30 minutes in an autoclave, then heating it to 117 ° C., adjusting the heating time as appropriate to expand about 10 times. A body sheet was made.
The obtained non-foamed extrudates and foamed extrudates were evaluated for properties and physical properties by the methods described above, and the results are shown in Table 2 below.

[Comparative Examples 1 to 4]
In Comparative Examples 1 to 4, resin composition pellets were obtained in the same manner as in Examples except that the composition was changed as shown in Table 2. Table 2 shows the results of measurement and evaluation of each physical property.

As shown in Table 2, Examples 1-13 have high flame resistance (0.8 mm thickness V-2, or burning rate of 85 mm/min or less), high heat resistance, and It is also found that the impact resistance is excellent. In addition, high flame retardancy can be obtained by optimizing the copolymerization ratio. Furthermore, by adding a phosphorus-based flame retardant or the like as component (D), high flame retardancy can be obtained by a synergistic effect.

Regarding Comparative Example 1, as shown in Table 2, flame retardancy cannot be obtained unless the (C) NOR-type hindered amine compound is added. It can be seen that the decrease in
Regarding Comparative Example 2, as shown in Table 2, when the content of the (C) NOR-type hindered amine compound is greater than a predetermined amount, the heat resistance, impact resistance, and sheet impact of non-foamed and foamed extruded sheets are greatly reduced. I understand.
Regarding Comparative Examples 3 and 4, as shown in Table 2, if the copolymer (B) is not added, the impact resistance is lowered, and if it is more than the predetermined amount, the flame retardancy and heat resistance are lowered, and the foamability is lowered. Therefore, it can be seen that the foam sheet impact is greatly reduced.

Molded articles containing the resin composition of the present invention include computer parts such as desktop personal computers and notebook personal computers, mobile phone parts, electrical/electronic equipment, personal digital assistants, home appliance parts, automobile parts, industrial materials, building materials, and the like. It can be suitably used for thin-walled products, sheets, films, foam boards, and the like.

Claims (6)

(A ) 86.5 to 99.3% by mass of copolymer resin, (B) 0.5 to 10.0% by mass of maleic anhydride-modified ethylene-α-olefin copolymer, and (C) 0 NOR type hindered amine compound .2 to 3.5% by mass ,
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 in the (A) copolymer resin is 100% by mass, the Containing 67.0 to 96.0% by mass of styrene-based monomer units, and containing 4.0 to 18.0% by mass of the unsaturated carboxylic acid-based monomer units, and the unsaturated carboxylic acid A flame-retardant styrene resin composition containing 0 to 15.0% by mass of an acid ester monomer unit . 2. The flame-retardant styrenic resin composition according to claim 1 , wherein the maleic anhydride-modified ethylene-α-olefin copolymer (B) has a maleic anhydride grafting rate of 0.5 to 2.0% by mass. thing. Furthermore, (D) one or more flame retardants selected from the group consisting of phosphorus-based flame retardants and bromine-based flame retardants are added to 100 parts by mass of the total amount of the components (A), (B), and (C). The flame-retardant styrenic resin composition according to any one of claims 1 or 2 , comprising 1.0 to 10.0 parts by mass with respect to the. A molded article comprising the flame-retardant styrene resin composition according to any one of claims 1 to 3 . A non-foamed extruded sheet formed using the flame-retardant styrenic resin composition according to any one of claims 1 to 3 . A foam extruded sheet formed using the flame-retardant styrene resin composition according to any one of claims 1 to 5 .