JP2016210933A - Thermoplastic resin composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition excellent in flame retardancy, antistatic properties, lasting antistatic properties, and heat resistance, and to provide a molded article thereof.SOLUTION: The thermoplastic resin composition contains: a graft copolymer (A) obtained by graft-polymerizing a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the presence of a rubbery polymer; a copolymer (B) obtained by copolymerizing a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the absence of a rubbery polymer; a halogen atom-containing flame retardant (C) having a mass average molecular weight of 1,000 or more; and a polymer type antistatic agent (D). The content of the halogen atom-containing flame retardant (C) and the content of the polymer type antistatic agent (D) are 27-40 pts.mass and 13-25 pts.mass, respectively, based on 100 pts.mass of the total of the graft copolymer (A) and the copolymer (B). The molded article is obtained by molding the thermoplastic resin composition.SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin composition, and more particularly, to a thermoplastic resin composition excellent in flame retardancy, antistatic property, sustained antistatic property, and heat resistance. The present invention also relates to a molded article formed by molding this thermoplastic resin.

  Thermoplastic resin is accumulated without being able to release static electricity caused by friction due to its high electrical insulation, causing dust in the air to adhere, causing contamination, and system failure due to IC malfunction in electronic devices Cause various problems.

  In recent years, products such as home appliances and OA devices are closer to heat-generating components depending on the density of the housing due to miniaturization, so that practical strength may not be obtained if the heat-resistant temperature falls below 70 ° C. Therefore, heat resistance is also important.

  As described above, the required characteristics of the molding material are different for each part, but from the viewpoint of productivity and safety, the parts to be used are required to satisfy all these characteristics at a high level.

  In order to prevent static electricity-derived problems, it is known to use an antistatic agent for the purpose of quickly releasing the generated static electricity. As this antistatic agent, there are a method of applying a surfactant to the surface of a resin molded product and a method of kneading it inside. This technique utilizes the function of a highly hydrophilic surfactant to release static electricity through moisture in the air.

  In addition, the method of adding carbon black as a conductive filler to the resin is excellent in the durability of the antistatic effect, has low humidity dependence, and is excellent in the stability of the antistatic effect.

  In recent years, a method of semipermanently imparting an antistatic effect by blending a polymer-type antistatic agent with a thermoplastic resin has been taken (Patent Documents 1 and 2).

JP 2009-173758 A JP 2012-241153 A

As an antistatic agent, the method of applying a surfactant to the surface of a resin molded product or the method of kneading it inside removes the surfactant simply by washing with water or wiping, so the antistatic effect does not last. was there.
In the method of adding carbon black to a thermoplastic resin, a large amount of addition is required to develop antistatic performance, resulting in instability in flame retardancy, which tends to be incompatible with the V-0 standard in the UL94 test.
Even in the method of blending a polymer type antistatic agent with a thermoplastic resin, a large amount of blending is required to obtain a sufficient antistatic effect, the heat resistance is lowered, and further the water absorption of the polymer type antistatic agent causes the surface of the molded product. However, there is a problem that the appearance swells in spots due to moisture.

  As described above, the conventional technology cannot satisfy market demands at a high level, and it has been desired to solve these problems with a new technology.

  An object of the present invention is to provide a thermoplastic resin composition excellent in flame retardancy, antistatic property, sustained antistatic property, and heat resistance, and a molded product formed by molding this thermoplastic resin composition. .

As a result of intensive studies, the present inventors limited the halogen atom-containing flame retardant (C) and the polymer type antistatic agent (D) to the specific graft copolymer (A) and copolymer (B). It was found that the above-mentioned problems were solved by blending at the prescribed ratio, and the present invention was completed.
That is, the gist of the present invention is as follows.

[1] A graft copolymer (A) obtained by graft polymerization of a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the presence of a rubber polymer; A copolymer (B) obtained by copolymerizing a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the absence of the coalescence, and a halogen having a mass average molecular weight of 1000 or more Halogen atom-containing flame retardant (C) with respect to a total of 100 parts by mass of graft copolymer (A) and copolymer (B), including atom-containing flame retardant (C) and polymer-type antistatic agent (D) Is a thermoplastic resin composition in which the content of the polymer type antistatic agent (D) is 13 to 25 parts by mass.

[2] The thermoplastic resin composition according to [1], wherein the halogen atom-containing flame retardant (C) has a mass average molecular weight of 19000 or more.

[3] The thermoplastic resin composition according to [1] or [2], wherein the polymer type antistatic agent (D) is a polyether ester amide block polymer.

[4] The proportion of the graft copolymer (A) in the total of 100 parts by mass of the graft copolymer (A) and the copolymer (B) is 15 to 50 parts by mass, and the proportion of the copolymer (B) The thermoplastic resin composition according to any one of [1] to [3], wherein is from 85 to 50 parts by mass.

[5] A molded product formed by molding the thermoplastic resin composition according to any one of [1] to [4].

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin composition excellent in the flame retardance, antistatic property, sustained antistatic property, and heat resistance, and its molded article are provided.

  Hereinafter, embodiments of the present invention will be described in detail.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention is a graft copolymer obtained by graft polymerization of a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the presence of a rubbery polymer ( A), a copolymer (B) obtained by copolymerizing a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the absence of a rubbery polymer, and a mass average Halogen with respect to a total of 100 parts by mass of the graft copolymer (A) and the copolymer (B), comprising a halogen atom-containing flame retardant (C) having a molecular weight of 1000 or more and a polymer-type antistatic agent (D). The content of the atom-containing flame retardant (C) is 27 to 40 parts by mass, and the content of the polymer antistatic agent (D) is 13 to 25 parts by mass.

<Graft copolymer (A)>
The graft copolymer (A) used in the present invention is obtained by graft polymerization of a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the presence of a rubbery polymer.

The rubbery polymer used for the graft copolymer (A) is not particularly limited, but examples thereof include diene rubbers such as polybutadiene, alkyl (meth) acrylate rubbers such as butyl acrylic rubber, and ethylene-propylene rubbers. Examples thereof include ethylene-propylene copolymer rubber, polyorganosiloxysan rubber, diene / alkyl (meth) acrylate composite rubber, polyorganosiloxysan / alkyl (meth) acrylate composite rubber, and the like. Preferred are diene rubbers such as polybutadiene and diene / alkyl (meth) acrylate composite rubbers.
These rubbery polymers can be used alone or in combination of two or more.

  The gel content of the rubbery polymer is preferably 60 to 95% by mass, more preferably 70 to 95% by mass, and particularly preferably 72 to 85% by mass. When the gel content is within this range, the properties of the resulting thermoplastic resin composition, particularly the heat resistance, can be improved.

  In order to measure the gel content of the rubber polymer, specifically, the weighed rubber polymer was dissolved in an appropriate solvent at room temperature (23 ° C.) over 20 hours, and then 100 mesh. After separating with a wire mesh, the insoluble matter remaining on the wire mesh is dried at 60 ° C. for 24 hours and then weighed. The ratio (mass%) of the insoluble matter with respect to the rubber-like polymer before fractionation is calculated | required, and it is set as the gel content of a rubber-like polymer. As the solvent used for dissolving the rubbery polymer, for example, toluene is used for polybutadiene and acetone is used for polybutyl acrylate.

  The particle size of the rubbery polymer is not particularly limited, but the average particle size is preferably 0.20 to 0.45 μm, and more preferably 0.25 to 0.40 μm. The average particle size of the rubbery polymer can be measured by an optical method before graft polymerization. Further, after graft polymerization, the average particle diameter can be calculated using a transmission electron microscope (TEM) after dyeing the rubber polymer with a dyeing agent.

The monomer component to be graft-polymerized on the rubber polymer is a monomer mixture containing at least an aromatic vinyl compound and a vinyl cyanide compound.
Examples of the aromatic vinyl compound include styrene, α-methylstyrene, vinyltoluene and the like. An aromatic vinyl compound can be used individually by 1 type or in combination of 2 or more types.
Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. A vinyl cyanide compound can be used individually by 1 type or in combination of 2 or more types.

  Use of a mixture of an aromatic vinyl compound, preferably styrene, and a vinyl cyanide compound, preferably acrylonitrile, as the monomer component of the graft portion is preferred because the resulting graft copolymer (A) has excellent thermal stability. . In this case, the ratio of the aromatic vinyl compound such as styrene and the vinyl cyanide compound such as acrylonitrile is preferably 10 to 50% by mass with respect to 50 to 90% by mass of the aromatic vinyl compound ( However, the total of the aromatic vinyl compound and the vinyl cyanide compound is 100% by mass.)

  The monomer mixture that is graft-polymerized to the rubber polymer may contain other monomer components other than the aromatic vinyl compound and the vinyl cyanide compound. Other monomer components include methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, and 2-ethylhexyl methacrylate, and acrylic acid esters such as methyl acrylate, ethyl acrylate, and butyl acrylate (hereinafter referred to as “(meth) acrylic acid esters”). In the case where these (meth) acrylic acid esters are included in the monomer mixture, the content thereof is 50% by mass or less, particularly 30% by mass or less. From the viewpoint of improving the thermal stability of the graft copolymer (A), the monomer mixture preferably does not contain other monomer components other than the aromatic vinyl compound and the vinyl cyanide compound. .

  The graft copolymer (A) is obtained by emulsion graft polymerization of 90 to 20% by mass of the graft monomer component with respect to 10 to 80% by mass of the rubbery polymer (however, the rubber polymer and 100% by mass in total with the monomer components) is preferable because the resulting molded article has an excellent appearance. More preferably, in the graft copolymer (A), the rubber-like polymer is 30 to 70% by mass, and the graft part monomer component is 70 to 30% by mass.

  The graft copolymer (A) is preferably produced by emulsion graft polymerization, and the emulsion graft polymerization at that time is performed by a radical polymerization technique using an emulsifier. Various chain transfer agents for controlling the graft ratio and the molecular weight of the graft component can be added to the graft portion monomer component.

  The radical polymerization initiator used in the graft polymerization is not particularly limited, but a peroxide, an azo initiator, or a redox initiator combined with an oxidizing agent / reducing agent is used. Of these, redox initiators are preferred, especially redox initiators that combine ferrous sulfate, sodium pyrophosphate, glucose, hydroperoxide, ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, longalite, hydroperoxide. Agents are preferred.

  There are no particular restrictions on the emulsifier, but since it has excellent latex stability during emulsion polymerization and can increase the polymerization rate, various kinds of sodium sarcosinate, potassium fatty acid, sodium fatty acid, dipotassium alkenyl succinate, rosin acid soap, etc. An anionic emulsifier selected from carboxylates, alkyl sulfates, sodium alkylbenzene sulfonate, sodium polyoxyethylene nonylphenyl ether sulfate and the like is preferably used. These are properly used according to the purpose. The emulsifier used for the preparation of the rubbery polymer can be used as it is, and no additional emulsifier can be added during the emulsion graft polymerization.

  In the production of a general graft copolymer, a latex of the graft copolymer is obtained by graft polymerization of the monomer component to the rubber polymer by emulsion polymerization, and the obtained latex of the graft copolymer is obtained. The graft copolymer powder can be obtained through solidification, washing, dehydration, and drying.

  When the graft copolymer (A) is coagulated from the latex of the graft copolymer (A) to form a slurry, for example, the graft copolymer (A) latex is put into hot water in which a coagulant is dissolved. Thus, a wet method for coagulating into a slurry can be employed. Here, examples of the coagulant used include inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid, and metal salts such as calcium chloride, calcium acetate, and aluminum sulfate, and are selected according to the emulsifier used in the polymerization. The That is, when only a carboxylic acid soap such as fatty acid soap or rosin acid soap is used as an emulsifier, the graft copolymer (A) can be coagulated and precipitated using any coagulant, From the viewpoint of stability, it is preferable to solidify and precipitate the graft copolymer (A) using an inorganic acid. When an emulsifier exhibiting stable emulsifying power is contained even in an acidic region such as sodium alkylbenzene sulfonate, the recovered solution becomes turbid with the above-mentioned inorganic acid, and the precipitation of the graft copolymer (A) is difficult. It is necessary to use a metal salt as an agent.

Graft ratio of the graft copolymer (A) thus obtained (determined from the amount of acetone-soluble and insoluble components in the graft copolymer (A) and the weight of the rubbery polymer in the graft copolymer (A)). ), And the reduced viscosity (measured as a N, N-dimethylformamide solution at 25 ° C. at 0.2 g / dL, acetone) is not particularly limited, and those having an arbitrary structure may be used depending on the required performance. However, from the viewpoint of balance of physical properties, the graft ratio is preferably 5 to 150%, and the reduced viscosity of the acetone-soluble component is preferably 0.2 to 2.0 dL / g.
In addition, the graft ratio of the graft copolymer (A) and the reduced viscosity of the acetone-soluble component are specifically determined by the method described in the section of Examples described later.

  In the thermoplastic resin composition of the present invention, only one kind of the graft copolymer (A) may be used, and two kinds of the rubbery polymer, the monomer composition of the graft part, and the physical properties are different. A combination of the above may also be used.

<Hard copolymer (B)>
The hard copolymer (B) used in the present invention is obtained by polymerizing a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the absence of a rubbery polymer. It is. The ratio of the vinyl cyanide compound and the aromatic vinyl compound in the monomer mixture is preferably 10 to 60% by mass of the vinyl cyanide compound and 40 to 90% by mass of the aromatic vinyl compound (however, the aromatic vinyl compound The total of the compound and the vinyl cyanide compound is 100% by mass.), More preferably 15 to 55% by mass of the vinyl cyanide compound and 45 to 85% by mass of the aromatic vinyl compound. Is 20 to 50% by mass and the aromatic vinyl compound is particularly preferably 50 to 80% by mass (however, the total of the aromatic vinyl compound and the vinyl cyanide compound is 100% by mass).
When the proportion of the vinyl cyanide compound is not less than the above lower limit, the resulting thermoplastic resin composition has good impact resistance, and when it is not more than the above upper limit, thermal coloring of the thermoplastic resin composition is suppressed. .

  In addition, the monomer mixture used for manufacture of a copolymer (B) may contain other monomer components other than a vinyl cyanide compound and an aromatic vinyl compound. Examples of other monomer components include (meth) acrylic acid esters. When these (meth) acrylic acid esters are included in the monomer mixture, the content thereof is 50% by mass or less, particularly 30%. The monomer mixture is preferably a monomer component other than the vinyl cyanide compound and the aromatic vinyl compound, from the viewpoint of improving the impact resistance and the like of the copolymer (B). It is preferable not to contain.

  Examples of the vinyl cyanide compound, aromatic vinyl compound and (meth) acrylic acid ester used for the production of the hard copolymer (B) are those exemplified as the monomer components used for the production of the graft copolymer (A). Can be used.

  The hard heavy copolymer (B) can be obtained as a latex hard copolymer (B) by carrying out emulsion polymerization using the monomer mixture described above, and subjecting it to the next mixing step as it is. This is preferable. About the emulsifier and initiator used in that case, the thing similar to what was illustrated as what is used for manufacture of a graft copolymer (A) can be used.

  The hard copolymer (B) has a reduced viscosity (hereinafter simply referred to as “reduced viscosity”) measured at 25 ° C. of a solution obtained by dissolving 0.2 g of the hard copolymer (B) in 100 ml of dimethylformamide. / G is preferable. This reduced viscosity is more preferably 0.35 to 1.0 dL / g, and particularly preferably 0.4 to 0.6 dL / g. When the reduced viscosity of the hard copolymer (B) is 0.3 dL / g or more, the resulting thermoplastic resin composition has good impact resistance, while when it is 2.0 dL / g or less, The fluidity of the plastic resin composition is good and the moldability is excellent.

  Any method may be used to adjust the reduced viscosity of the hard copolymer (B). However, a method of changing or using the chain transfer agent, a method of changing the amount of initiator used, a polymerization temperature, And a method of changing a method for supplying a monomer as a raw material.

  In the thermoplastic resin composition of the present invention, only one type of copolymer (B) may be used, or two or more types having different monomer compositions and physical properties may be used in combination.

<Ratio of graft copolymer (A) and copolymer (B)>
In the thermoplastic resin composition of the present invention, the blending ratio of the graft copolymer (A) and the copolymer (B) is not particularly limited, but the graft copolymer (A) and the copolymer (B). The proportion of the graft copolymer (A) in the total 100 parts by mass of 15 to 50 parts by mass and the proportion of the copolymer (B) is preferably 85 to 50 parts by mass, and the graft copolymer (A ) Is 20 to 40 parts by mass, and the copolymer (B) is more preferably 80 to 60 parts by mass. By blending the graft copolymer (A) and the copolymer (B) so as to have the above ratio, the effects such as heat resistance and antistatic properties are excellent.

<Halogen atom-containing flame retardant (C)>
The halogen atom-containing flame retardant (C) used in the present invention has a mass average molecular weight of 1000 or more, preferably 2100 or more, more preferably 19000 or more. When the mass average molecular weight is less than 1000, the resulting thermoplastic resin composition has poor antistatic properties and sustained antistatic properties, and also has insufficient heat resistance. However, if the mass average molecular weight of the halogen atom-containing flame retardant (C) is excessively large, fluidity may be insufficient when molding a large molded article. Therefore, the mass average molecular weight of the halogen atom-containing flame retardant (C) may be insufficient. Is preferably 40000 or less. Here, the mass average molecular weight of the halogen atom-containing flame retardant (C) is a value calculated from the structural formula, or a published value of the manufacturer can be used.

Examples of the halogen atom-containing flame retardant (C) include a chlorine-based flame retardant, a bromine-based flame retardant, and a fluorine-based flame retardant.
Among these, chlorine-based flame retardants and bromine-based flame retardants can be preferably used, and bromine-based flame retardants can be particularly preferably used.

  Examples of the chlorinated flame retardant include chlorinated paraffin and chlorinated polyethylene.

  Examples of the brominated flame retardant include brominated bisphenol A type epoxy polymer having a molecular weight of 1000 or more, pentabromobenzyl polyacrylate, brominated polycarbonate oligomer, and triazine flame retardant.

  Among the brominated flame retardants, brominated bisphenol A type epoxy polymers are preferable. When the brominated bisphenol A type epoxy polymer is employed as a flame retardant, the heat resistance and the sustained antistatic property can be further improved.

  In the thermoplastic resin composition of the present invention, the blending amount of the halogen atom-containing flame retardant (C) is 27 to 40 parts by mass with respect to 100 parts by weight of the total of the graft copolymer (A) and the hard polymer (B). Preferably, it is 30-40 mass parts. When the blending amount of the halogen atom-containing flame retardant (C) is less than 27 parts by mass, the flame retardancy is insufficient, and when it exceeds 40 parts by mass, the heat resistance is inferior.

  A halogen atom containing flame retardant (C) can be used individually by 1 type or in combination of 2 or more types.

  In the present invention, a flame retardant aid may be used in combination with the halogen atom-containing flame retardant (C). As the flame retardant aid, an antimony flame retardant aid such as antimony trioxide, antimony pentoxide, sodium antimonate, metal antimony, antimony trichloride, or antimony pentachloride can be suitably employed. Besides these, barium metaborate, zirconium oxide, and the like can also be employed. These flame retardant aids can be used singly or in combination of two or more. Of the various flame retardant aids described above, antimony flame retardants are preferred, and antimony trioxide can be particularly preferably employed.

  When the flame retardant aid is used, the blending amount is preferably 1 to 20 parts by weight, particularly preferably 2 with respect to 100 parts by weight of the total of the graft copolymer (A) and the hard polymer (B). ~ 8 parts by weight. When the flame retardant aid is used within this range, the expression of the flame retardant effect and the color developability are improved.

<Polymer type antistatic agent (D)>
In the present invention, the polymer type antistatic agent (D) is preferably a polyether block polyolefin copolymer or polyoxyalkylene type because it can effectively exhibit antistatic properties in the presence of a thermoplastic resin. Examples thereof include a copolymer, a polyether ester amide polymer, and an ethylene oxide-propylene oxide-allyl glycidyl copolymer.

  Furthermore, since it is possible to suppress appearance defects due to the swelling phenomenon of the surface of the molded product that occurs in a wetness environment, a polyether ester amide block polymer in which polyamide blocks and polyether blocks are repeatedly bonded alternately via ester bonds is preferable. .

  The number average molecular weight of the polymer type antistatic agent (D) is usually 1000 to 100,000, preferably 2000 to 60000, and more preferably 2000 to 50000 in terms of polystyrene. Here, the molecular weight of the polymer type antistatic agent (D) is, for example, a value measured by gel permeation chromatography using hexafluoroisopropanol as a solvent.

  The melting point of the polymer type antistatic agent (D) is preferably 150 to 250 ° C, more preferably 160 to 240 ° C, and further preferably 170 to 230 ° C. Here, the melting point of the polymer type antistatic agent (D) can be measured by a differential scanning calorimeter (DSC).

Further, the surface resistivity (Ω) of the polymer type antistatic agent (D) is preferably 1 × 10 ⁶ to 1 × 10 ¹⁰ when left standing at a temperature of 23 ° C. and a humidity of 50% RH for 24 hours, for example. preferably ^{5 × 10 6 ~1 × 10 9} , more preferably from 1 × ¹⁰ 7 ~1 × ¹⁰ about ^9.

  Examples of commercially available polyether ester amide block polymers include “Pelestat NC6321” manufactured by Sanyo Chemical Industries, Ltd.

  In the thermoplastic resin composition of the present invention, the blending amount of the polymer-type antistatic agent (D) is 13 to 25 weights with respect to 100 parts by weight of the total of the graft copolymer (A) and the hard polymer (B). Part, preferably 15 to 20 parts by weight. When the blending amount of the polymer type antistatic agent (D) is less than 13 parts by mass, the antistatic property is poor, and even if it exceeds 25 parts by mass, no further effect of improving the antistatic property can be obtained. In some cases, the mechanical properties and the like are deteriorated, and the problem of the swelling phenomenon of the surface of the molded product that occurs in the wetness environment may occur.

  A polymer type antistatic agent (D) can be used individually by 1 type or in combination of 2 or more types.

<Other additives>
The thermoplastic resin composition of the present invention is within the range not impairing its physical properties, and other usual additives used at the time of production (mixing) or molding of the resin composition, for example, dyes, pigments, stabilizers, reinforcements An agent, a filler, a foaming agent, a lubricant, a plasticizer, an oxidative degradation inhibitor, a weathering agent, a release agent, and the like may be contained as necessary.

  Moreover, if it is a range below 10 mass parts with respect to the total 100 mass parts of a graft copolymer (A) and a copolymer (B), for example to the extent which does not impair the objective of this invention, a graft copolymer Resins other than (A) and the copolymer (B), rubber, elastomer and the like may be contained.

<Manufacturing method>
There is no restriction | limiting in particular in the method to manufacture the thermoplastic resin composition of this invention, The thermoplastic resin composition of this invention can be manufactured using the method and apparatus currently performed normally. A generally used method is a melt mixing method, and examples of the apparatus used at that time include a single screw extruder, a twin screw extruder, a Banbury mixer, a roller, and a kneader. The production of the thermoplastic resin composition may be carried out either batchwise or continuously, and there is no particular limitation on the mixing order of the components, and it is sufficient that all the components are mixed sufficiently uniformly.

[Molding]
The thermoplastic resin composition of the present invention is made a desired molded article by various molding methods such as injection molding, extrusion molding, blow molding, compression molding, calendar molding, inflation molding and the like.

  The molded product of the present invention formed by molding the thermoplastic resin composition of the present invention is excellent in a highly balanced flame retardancy, sustained antistatic property and heat resistance. Examples of industrial applications include vehicle parts and walls. Building materials parts such as wood and window frames, tableware, toys, vacuum cleaner housings, television housings, air conditioner housings and other home appliance parts, mobile phones, smartphones, tablets, laptop computers, video cameras, digital cameras and other portable devices, telephones, Faxes, printers, copiers, desktop computers, and other office automation equipment, as well as dust and other deposits, not only for the above-mentioned housing but also for exterior and interior materials that require high appearance and high design. Can be used.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to synthesis examples, examples, and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the following, “part” means “part by mass” and “%” means “mass%”.

[Evaluation method]
In the following, evaluation methods for various physical properties and characteristics of the obtained resin composition are as follows.

<Flame retardance>
A test piece having a length of 125 ± 5 mm, a width of 13 ± 5 mm, and a thickness of 1.5 ± 0.15 mm was formed by a J75EII type injection molding machine manufactured by Nippon Steel, and the test piece was subjected to a test method of UL94 standard. The test was carried out and evaluated by whether or not it passed V-0.

<Electrical control>
The following test specimens were molded with a J75EII type injection molding machine manufactured by Nippon Steel Works, and the antistatic property was evaluated by measuring the surface specific resistance value in accordance with ASTM D257.
Test piece shape: 100 × 100 × 3 mm thick flat plate Test voltage: 1000V
Test time: 60 sec
When the power of the surface specific resistance value is 11 or less, the antistatic property is excellent.

<Sustained anti-electricity>
The test piece for the antistatic evaluation was immersed in warm water at 70 ° C. for 7 days, then lifted, and the surface moisture was wiped off. Then, the surface resistivity was measured in the same manner as the evaluation of the antistatic property.
When the power of the surface specific resistance value is 11 or less, the excellent antistatic performance is obtained.

<Heat resistance>
A test piece was molded with a J75EII type injection molding machine manufactured by Nippon Steel Works, and the deflection temperature under load was measured according to ISO 75. The test load was 1.80 MPa, and the test piece thickness was 4 mm.
If the deflection temperature under load was higher than 70 ° C., it was judged that there was no practical problem.

<Appearance evaluation>
A test piece for appearance evaluation was molded using a J75EII type injection molding machine manufactured by Nippon Steel Works, using a mold for appearance evaluation (plate-shaped molded product of 100 mm × 100 mm × 3 mm). The cylinder temperature of the injection molding machine was 220 ° C., and the mold temperature was 60 ° C. After the obtained test piece was exposed to the following conditions 1 and 2, the surface of the test piece was visually observed and evaluated according to the following criteria.
(Environmental exposure conditions for evaluation specimens)
Condition 1: Evaluation was performed after exposure to an environment of temperature 70 ° C. and humidity 95% RH for 7 days.
Condition 2: Evaluation was performed after dipping in hot water at 70 ° C. for 7 days and then wiping off surface moisture.
(Evaluation criteria)
○: No blistering or the like on the test piece and no problem in appearance △: Very small blistering on the test piece, but no problem for practical use ×: Many blisters on the test piece, causing a practical problem

[Production of graft copolymer]
The graft ratio of the graft copolymer (A-1) produced in Synthesis Example 1 below and the reduced viscosity of the acetone-soluble component were measured by the following method.

<Graft ratio of graft copolymer>
80 mL of acetone was added to 2.5 g of the graft copolymer, and the mixture was refluxed in a 65 ° C. water bath for 3 hours to extract acetone-soluble components. The remaining acetone insolubles were separated by centrifugation, the weight after drying was measured, and the weight ratio of acetone insolubles in the graft copolymer was calculated. The graft ratio was calculated from the weight ratio of acetone insolubles in the obtained graft copolymer using the following formula.

<Reduced viscosity of acetone-soluble matter of graft copolymer>
About the N, N-dimethylformamide solution prepared so that the concentration of the acetone soluble part of the graft copolymer is 0.2 g / dL, the reduced viscosity at 25 ° C. using an Ubbelohde viscometer: η _sp / C ( Unit: dL / g) was measured.

<Synthesis Example 1: Production of Graft Copolymer (A-1)>
A graft copolymer (A-1) was produced with the following composition.
[Combination]
50 parts of polybutadiene latex (as solids)
Styrene (ST) 38.5 parts Acrylonitrile (AN) 11.5 parts Disproportionated potassium rosinate 0.6 parts Potassium hydroxide 0.03 parts Tertiary decyl mercaptan (t-DM) 0.17 parts Cumene hydroperoxide 0.30 parts Ferrous sulfate 0.007 parts Sodium pyrophosphate 0.12 parts Crystalline glucose 0.30 parts Distilled water 190 parts

  The autoclave is charged with distilled water, disproportionated potassium rosinate, potassium hydroxide and polybutadiene latex (gel content 82%, average particle size 0.31 μm, solid content 34.0%), heated to 60 ° C. Add ferrous iron, sodium pyrophosphate, and crystalline glucose, and continuously add ST, AN, t-DM and cumene hydroperoxide over 2.5 hours while maintaining the temperature at 60 ° C. The reaction was completed for 1 hour. An antioxidant was added to the graft copolymer latex obtained by this reaction to obtain a graft copolymer (A-1). The solid content of the graft copolymer (A-1) in the obtained latex was 33.2%, the graft ratio was 64.4%, and the reduced viscosity of the acetone-soluble component was 0.47 dL / g. The resulting polymer latex was diluted 1.25 times with distilled water and gradually dropped into a 3% aqueous sulfuric acid solution at 50 ° C. After dropping the whole amount, the temperature was raised to 90 ° C. and held for 5 minutes to solidify. Next, the coagulated product was separated with a filter cloth, washed so that the content of the emulsifier residue was 1% or less, and then dried to obtain a graft copolymer-containing (A-1) powder.

[Manufacture of hard copolymer]
The reduced viscosity of the hard copolymer (B-1) produced in Synthesis Example 2 below was prepared by dissolving 0.2 g of a powdery copolymer recovered from a latex in 100 ml of dimethylformamide and using an Ubbelohde viscometer. And measured at 25 ° C.

<Synthesis Example 2: Production of Rigid Copolymer (B-1)>
A 5 L glass reactor equipped with a stirrer, a thermometer and a jacket-type temperature controller was charged with 335.7 parts of water, dipotassium alkenyl succinate (DR-25K manufactured by Arakawa Chemical Industries, Ltd., as an actual amount) 2.0. Part, 25 parts of acrylonitrile (AN), 75 parts of styrene (ST) and 0.4 part of terrestrial decyl mercaptan were added, and the internal temperature was raised to 70 ° C. with stirring. After confirming that the system was in a suspended state, an aqueous solution consisting of 0.25 parts of sodium persulfate and 15.3 parts of water was added. When the jacket temperature was maintained at that temperature, heat was rapidly generated from about 30 minutes later, and the internal temperature rose to 85 ° C. After the exotherm has subsided, the internal temperature becomes 70 ° C., hold for 1 hour, cool to 30 ° C., obtain a dehydration drying step, and obtain a hard copolymer (B-1) having a reduced viscosity of 0.59 dL / g. Obtained.

[Halogen atom-containing flame retardant (C)]
The following halogen atom-containing flame retardants were used.
C-1: Brominated flame retardant (brominated bisphenol A type epoxy polymer) EP-20 (mass average molecular weight 2000) manufactured by DIC Corporation
C-2: Brominated flame retardant (brominated bisphenol A type epoxy polymer) EP-200 (mass average molecular weight 20000) manufactured by DIC Corporation
c-1: Albemarle Japan Co., Ltd. Brominated flame retardant (brominated diphenylethane) Setex 8010 (mass average molecular weight 971)

[Polymer type antistatic agent (D)]
The following polymer type antistatic agents were used.
D-1: Pelestat NC6321 (polyether ester amide block polymer) manufactured by Sanyo Chemical Industries
D-2: Zeospan-8100L manufactured by Nippon Zeon Co., Ltd. (ethylene oxide / propylene oxide copolymer)

[Others]
The following were used as surfactants.
X-1: Nonionic surfactant TB-370 manufactured by Matsumoto Yushi Seiyaku Co., Ltd.

[Flame retardant aid]
Antimony trioxide was used as a flame retardant aid.

[Examples 1-7, Comparative Examples 1-6]
In the thermoplastic resin composition formulation shown in Table 1, each component was mixed with a Henschel mixer, and then kneaded with an extruder to be pelletized.
Each evaluation mentioned above was performed using the pellet of the obtained resin composition, and the results are shown in Table 1.

As is clear from Table 1, Examples 1 to 7 are excellent in flame retardancy, heat resistance, antistatic property, and sustained antistatic property of the thermoplastic resin composition. In addition, when a polyether ester amide block polymer is used as the polymer type antistatic agent (D), it is possible to suppress appearance defects due to the swelling phenomenon of the surface of the molded product that occurs in a wetness environment.
On the other hand, in Comparative Example 1 in which the blending amount of the halogen atom-containing flame retardant (C) is small, the flame retardancy is inferior, and in contrast, in Comparative Example 2 in which the amount is too large, the heat resistance is inferior.
In Comparative Example 3 using a brominated flame retardant having a low molecular weight, the heat resistance is poor, and the antistatic property and the sustained antistatic property are also poor.
In Comparative Example 4 in which the blending amount of the polymer type antistatic agent (D) is small, the antistatic property and the sustained antistatic property are inferior.
In Comparative Example 5 in which a nonionic surfactant is used instead of the polymer type antistatic agent (D), the antistatic property is poor and the sustained antistatic property is particularly inferior.
In Comparative Example 6 in which the blending amount of the polymer type antistatic agent (D) is too large, the heat resistance is lowered, and there is a problem of a swelling phenomenon of the surface of the molded product that occurs in a wetness environment.

Claims (5)

A graft copolymer (A) obtained by graft polymerization of a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the presence of a rubber polymer;
A copolymer (B) obtained by copolymerizing a monomer mixture containing a vinyl cyanide compound and an aromatic vinyl compound with a radical initiator in the absence of a rubbery polymer;
A halogen atom-containing flame retardant having a mass average molecular weight of 1000 or more (C);
A polymer-type antistatic agent (D),
The content of the halogen atom-containing flame retardant (C) is 27 to 40 parts by mass with respect to 100 parts by mass in total of the graft copolymer (A) and the copolymer (B), and the polymer type antistatic agent (D) is contained. A thermoplastic resin composition having an amount of 13 to 25 parts by mass.   The thermoplastic resin composition according to claim 1, wherein the halogen atom-containing flame retardant (C) has a mass average molecular weight of 19000 or more.   The thermoplastic resin composition according to claim 1 or 2, wherein the polymer type antistatic agent (D) is a polyether ester amide block polymer.   The ratio of the graft copolymer (A) in the total 100 parts by mass of the graft copolymer (A) and the copolymer (B) is 15 to 50 parts by mass, and the ratio of the copolymer (B) is 85 to 85 parts by mass. The thermoplastic resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin composition is 50 parts by mass.   The molded article formed by shape | molding the thermoplastic resin composition of any one of Claim 1 thru | or 4.