JP2022074542A - Thermoplastic resin composition - Google Patents

Abstract

To provide a thermoplastic resin composition which has excellent light discoloration resistance and maintains heat resistance and mechanical strength of a polyphenylene ether.SOLUTION: The thermoplastic resin composition contains (A) a polyphenylene ether-based resin, (B) a polyolefin resin, and (C) titanium oxide. The component (A) forms a continuous layer. The content of the component (A) is 30-90 mass% in 100 mass% of the thermoplastic resin composition. The mass ratio ((A)/(B)) of the component (A) to the component (B) is 99/1-70/30. The mass ratio ((B)/(C)) of the component (B) to the component (C) is 50/50-5/95.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic resin composition.

A polyphenylene ether-based resin composition (hereinafter, also referred to as “m-PPE resin composition”) based on a polyphenylene ether (hereinafter, also referred to as “PPE”)-based resin has heat resistance, electrical characteristics, and dimensional stability. It has features such as impact resistance and low specific gravity. Further, since the m-PPE resin composition can be made flame-retardant without using halogen compounds and antimony compounds having a large environmental load, various electric / electronic parts, office equipment parts, automobile parts, building materials, etc. In addition to being widely used in various other exterior materials and industrial products, in recent years it is expected to be used in high-speed communication board materials and peripheral members due to its low dielectric positive contact.
However, since the polyphenylene ether-based resin composition has a drawback that it is easily discolored to yellow by ultraviolet rays, there is a problem that its use is limited when it is colored in a chromatic color, particularly a bright color such as white in a molded product.

In Patent Document 1, an inorganic powder selected from the group consisting of titanium oxide having a specific average particle size, a mica coated with titanium oxide, barium sulfate, zinc oxide and zinc sulfide is constantly used for a polyolefin resin and a polyphenylene ether resin. A resin composition comprising a polyolefin and a polyphenylene ether resin, which is less discolored by light when added in an amount or more, has been proposed.

Patent Document 2 reports a method for improving weathering and discoloration resistance by reducing the content of a specific molecular terminal structural unit of polyphenylene ether to a predetermined value or less.

Japanese Patent Laid-Open No. 2004-204013 JP 2010-189517

However, in the resin composition disclosed in Patent Document 1, the polyolefin resin forms a continuous phase, and there is a problem that the mechanical strength, heat resistance, and impact resistance are lower than those of the polyphenylene ether resin itself. rice field.

Further, in the resin composition disclosed in Patent Document 2, the proportion of the polyphenylene ether resin is limited to 50% or less in order to keep the content of the terminal hydroxyl group of the polyphenylene ether to a predetermined value or less, and the heat resistance is improved. In addition to being unable to be raised, the extrusion process had to be carried out in two stages, making it difficult to put into practical use.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermoplastic resin composition having excellent photochromic resistance and maintaining the heat resistance and mechanical strength of polyphenylene ether. ..

As a result of diligent studies to solve the above problems, the present inventors have excellent light discoloration resistance by using a polyphenylene ether resin, a polyolefin resin and titanium oxide in combination and blending them in a specific ratio. We have found that we can provide a thermoplastic resin composition that maintains the heat resistance and mechanical strength of polyphenylene ether, and have arrived at the present invention.

That is, the present invention is as follows.
[1]
A thermoplastic resin composition containing (A) a polyphenylene ether-based resin, (B) a polyolefin resin, and (C) titanium oxide.
(A) The component forms a continuous layer,
The content of the component (A) in 100% by mass of the thermoplastic resin composition is 30 to 90% by mass.
The mass ratio of the component (A) / component (B) ((A) / (B)) is 99/1 to 70/30.
A thermoplastic resin composition, characterized in that the mass ratio of the component (B) / the component (C) ((B) / (C)) is 50/50 to 5/95.
[2]
The thermoplastic resin composition according to [1], further containing (D) a styrene resin and / or (E) an elastomer.
[3]
The thermoplastic resin composition according to [1] or [2], wherein the mass ratio ((A) / (B)) of the component (A) / component (B) is 99/1 to 80/20.
[4]
The thermoplastic resin composition according to any one of [1] to [3], wherein the mass ratio ((B) / (C)) of the component (B) / component (C) is 45/55 to 10/90. thing.
[5]
(F) The thermoplastic resin composition according to any one of [1] to [4], further containing a flame retardant.

According to the present invention, it is possible to provide a polyphenylene ether-based resin composition having high photochromic resistance while maintaining heat resistance and mechanical strength.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.

The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and carried out within the scope of the gist thereof.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present embodiment includes (A) a polyphenylene ether-based resin, (B) a polyolefin resin, and (C) titanium oxide, and optionally (D) a styrene-based resin and / or (E). ) Elastomer and (F) phosphorus-based flame retardant.
Here, the component (A) forms a continuous layer in the thermoplastic resin composition.
The content of the component (A) in 100% by mass of the thermoplastic resin composition is 30 to 90% by mass.
Further, the mass ratio of the component (A) / the component (B) ((A) / (B)) is 99/1 to 70/30, and the mass ratio of the component (B) / component (C) ((B)). / (C)) is 50/50 to 5/95.

Further, in the present specification, (A) polyphenylene ether-based resin is "(A) component", (B) polyolefin resin is "(B) component", (C) titanium oxide is "(C) component", (D). ) The styrene resin may be referred to as "(D) component", the (E) elastomer may be referred to as "(E) component", and the (F) flame retardant may be referred to as "(F) component".

Hereinafter, each component constituting the thermoplastic resin composition will be described in detail.

<(A) Polyphenylene ether-based resin>
The thermoplastic resin composition of the present embodiment contains (A) a polyphenylene ether-based resin. The (A) polyphenylene ether-based resin is not particularly limited, but may be a homopolymer or a copolymer having a repeating unit represented by the following general formula (1) and / or general formula (2). It is preferable to have. As will be described later, the (A) polyphenylene ether-based resin may be a modified product having a predetermined modifying group.
(A) Only one type of polyphenylene ether-based resin may be used alone, or two or more types may be mixed and used.

（一般式（１）及び（２）中、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９、Ｒ^１０は、各々独立して、水素原子、炭素数１～４のアルキル基、炭素数６～９のアリール基、又はハロゲン原子を表す。但し、Ｒ^９、Ｒ^１０は同時に水素原子ではない。）

In the general formulas (1) and (2), R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ are independently hydrogen atoms, alkyl groups having 1 to 4 carbon atoms, and carbon atoms. Represents an aryl group of 6 to 9 or a halogen atom, where R ⁹ and R ¹⁰ are not hydrogen atoms at the same time.)

The homopolymer of the polyphenylene ether is not limited to the following, and is, for example, poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4). -Phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene) ether, poly (2,6-di-n) -Propyl-1,4-phenylene) ether, poly (2-methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-phenylene) ether, poly (2-Methyl-6-chloroethyl-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-) Phenylene) Ether and the like can be mentioned. Of these, poly (2,6-dimethyl-1,4-phenylene) ether is preferable from the viewpoint of thermal stability.

The copolymer of polyphenylene ether is a copolymer having a repeating unit represented by the general formula (1) and / or the general formula (2) as a main repeating unit.
The term "main" means that the polyphenylene ether copolymer contains 60% by mass or more of the repeating units represented by the general formula (1) and / or the general formula (2).

The copolymer is not particularly limited, but for example, a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, and 2,6-dimethylphenol and o-cresol. Examples thereof include a copolymer of 2,6-dimethylphenol, 2,3,6-trimethylphenol and o-cresol.

(A) As the polyphenylene ether-based resin, various phenylene ether units other than the above general formulas (1) and (2) are partially structured as long as the heat resistance of the thermoplastic resin composition is not excessively lowered. It may contain a polyphenylene ether contained as. The phenylene ether unit is not limited to the following, but is described in, for example, Japanese Patent Laid-Open No. 01-297428 and Japanese Patent Application Laid-Open No. 63-301222, 2- (dialkylaminomethyl) -6. Examples thereof include a unit derived from -methylphenylene ether and a unit derived from 2- (N-alkyl-N-phenylaminomethyl) -6-methylphenylene ether.

(A) The reduced viscosity (ηsp / c, chloroform solution, measured at 30 ° C.) of the polyphenylene ether-based resin is preferably 0.25 to 0.60 dL / g from the viewpoint of fluidity, toughness and chemical resistance. , 0.35 to 0.55 dL / g, more preferably.
The reduced viscosity was measured at 30 ° C. by preparing a solution of 0.5 g of a sample / 100 mL of chloroform and using a Ubbelohde viscometer. The unit is dL / g.

（式中、２つのＲ^１１、２つのＲ^１２は、それぞれ独立して、水素原子、炭素数１～４のアルキル基、炭素数６～９のアリール基、又はハロゲン原子を表す。） The (A) polyphenylene ether-based resin preferably contains a structure (terminal hydroxyl group-containing portion) represented by the following general formula (3), and is represented by the following general formula (3) in the (A) polyphenylene ether-based resin. The amount of the structure (hydroxyl group amount) is preferably 0.8 or more per 100 repeating units constituting the (A) polyphenylene ether-based resin, and more preferably 1.0 or more.

(In the formula, the two R ^11s and the two R ^12s independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 9 carbon atoms, or a halogen atom.)

The amount of hydroxyl groups can be measured with a U3310 type spectrophotometer manufactured by Hitachi High-Technology Co., Ltd. based on the method described in Journal of Applied Polymer Science: Applied Polymer Symposium 34, 103-117 (1978). The unit of the amount of hydroxyl groups is a repeating unit constituting a polyphenylene ether-based resin (for example, a repeating unit derived from 2,6-dimethylphenol constituting a poly (2,6-dimethyl-1,4-phenylene) ether) 100. It is expressed by the number of hydroxyl groups represented by the following general formula (3) per unit.

(A) The amount of hydroxyl groups of the polyphenylene ether-based resin varies depending on, for example, the conditions for polymerizing the phenolic compound and the conditions for the quinone reaction after the polymerization is stopped. As an example of polymerization, poly (2,6-dimethyl-1,4-phenylene) ether is described in JP-A-2000-281767 and JP-A-2000-281778, and a monomer of a PPE-based resin is described at the time of polymerization. (For example, 2,6-dimethylphenol in the case of poly (2,6-dimethyl-1,4-phenylene) ether) The amount of quinone compound produced varies depending on the amount and time of addition. In general, the larger the amount to be added and the shorter the addition time, the larger the amount of the quinone compound produced. In the quinone reaction after the polymerization is stopped, the terminal hydroxyl group concentration changes depending on the temperature and time, and the higher the temperature and the longer the time, the higher the hydroxyl group concentration. In the present invention, the conditions for polymerizing the phenolic compound and the conditions for the quinone reaction after the polymerization is stopped are not limited, and a quinone compound is generally added to a PPE-based resin obtained by polymerization to cause a quinone reaction to cause a hydroxyl group. You can also increase the amount.

In the present embodiment, the (A) polyphenylene ether-based resin can be synthesized by any method. For example, when a catalyst having a copper atom is used, the copper content due to the residual catalyst is preferably 2.0 mass ppm or less based on the mass of the polyphenylene ether-based resin. If the copper content of the polyphenylene ether-based resin exceeds 2.0 mass ppm, the thermal stability of the thermoplastic resin composition will decrease, which may cause a decrease in impact resistance when exposed to high temperatures for a long period of time. .. The copper content of the polyphenylene ether-based resin is preferably 1.0 mass ppm or less, more preferably 0.5 mass ppm or less.

In the present embodiment, as the (A) polyphenylene ether-based resin, a modified polyphenylene ether obtained by modifying a part or all of the polyphenylene ether with an unsaturated or saturated carboxylic acid or a derivative thereof or a phosphorus-based compound can be used.

Examples of the modified polyphenylene ether include JP-A-2-276823 (US Pat. No. 5,159,027, US Reissue Patent Invention No. 35695) and JP-A-63-108059 (US Pat. No. 5,214,109). , 5216089), Japanese Patent Application Laid-Open No. 59-59724, Japanese Patent No. 6674477, and the like.

The modified polyphenylene ether is, for example, in the presence or absence of a radical initiator, in the presence or absence of a radical initiator, an unsaturated or saturated carboxylic acid or a derivative thereof, phosphonic acids, phosphonic acid esters, phosphinic acids, phosphinic acid esters, mono. It can be produced by melt-kneading and reacting carboxylic acids, sulfonic acids, sulfin acids, carbonates and the like. Alternatively, it can be produced by dissolving a polyphenylene ether and an unsaturated or saturated carboxylic acid or a derivative thereof in an organic solvent in the presence or absence of a radical initiator and reacting them in a solution.

The unsaturated carboxylic acid or a derivative thereof is not limited to the following, and is, for example, maleic acid, fumaric acid, itaconic acid, halogenated maleic acid, cis-4-cyclohexene1,2-dicarboxylic acid, endo. -Cis-bicyclo (2,2,1) -5-heptene-2,3-dicarboxylic acids, acid anhydrides of these dicarboxylic acids, esters of these dicarboxylic acids, amides of these dicarboxylic acids, and imides of these dicarboxylic acids; Examples thereof include acrylic acids, methacrylic acids, esters of these monocarboxylic acids, and amides of these monocarboxylic acids.

As the saturated carboxylic acid or a derivative thereof, in the present embodiment, a compound that can be thermally decomposed by itself at the reaction temperature at the time of producing the modified polyphenylene ether to become a derivative of the modified polyphenylene ether, specifically, malic acid or citric acid. And so on.

Examples of phosphonic acids include phosphonic acid (phosphonic acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylene diphosphonic acid, and 1-hydroxy. Examples thereof include ethane-1,1-diphosphonic acid, 4-methoxyphenylphosphonic acid, propylphosphonic acid anhydride and the like.

Examples of phosphonic acid esters include dimethyl phosphonate, diethyl phosphonate, bis (2-ethylhexyl) phosphonate, dioctyl phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, and dimethyl methyl phosphonate. Diphenyl methylphosphonate, dioctyl methylphosphonate, diethyl ethylphosphonate, dioctyl ethylphosphonate, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, dioctyl phenylphosphonate, diethyl (methoxymethyl) phosphonate , (Methicmethyl) phosphonate dioctyl, vinylphosphonate diethyl, vinylphosphonate diethyl, hydroxymethylphosphonate diethyl, hydroxymethylphosphonate diethyl, (2-hydroxyethyl) phosphonate dimethyl, (methoxymethyl) phosphonate dioctyl, p-methyl Diethyl benzylphosphonate, dioctyl p-methylbenzylphosphonate, diethylphosphonoacetic acid, ethyl diethylphosphonoacetate, tert-butyl diethylphosphonoacetate, dioctyl diethylphosphonate, diethyl (4-chlorobenzyl) phosphonate, (4-) Chlorobenzyl) dioctylphosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, dioctyl cyanophosphonate, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl, 3,5-di-tert-butyl- Examples thereof include dioctyl 4-hydroxybenzylphosphonate and diethyl (methylthiomethyl) phosphonate.

Examples of phosphinic acids include dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, diphenylphosphinic acid, dioleylphosphinic acid, 9,10-dihydro-9-oxa-10-phos. Examples thereof include faphenanthrene-10-oxide and derivatives thereof.

Examples of phosphinic acid esters include methyl dimethylphosphinate, ethyl dimethylphosphinate, n-butyl dimethylphosphinate, cyclohexyl dimethylphosphinate, vinyl dimethylphosphinate, phenyl dimethylphosphinate, methyl ethylmethylphosphinate, and ethylmethylphosphine. Ethyl acid, n-butyl ethylmethylphosphinate, cyclohexyl ethylmethylphosphinate, vinyl ethylmethylphosphinate, phenyl ethylmethylphosphinate, methyl diethylphosphinate, ethyl diethylphosphinate, n-butyl diethylphosphinate, cyclohexyl diethylphosphinate , Vinyl diethylphosphinate, phenyl diethylphosphinate, methyl diphenylphosphinate, ethyl diphenylphosphinate, n-butyl diphenylphosphinate, cyclohexyl diphenylphosphinate, vinyl diphenylphosphinate, phenyldiphenylphosphinate, methyl-n-propylphosphinic acid Methyl, ethyl methyl-n-propylphosphinate, n-butyl methyl-n-propylphosphinate, cyclohexyl methyl-n-propylphosphinate, vinyl methyl-n-propylphosphinate, phenylmethyl-n-propylphosphinate, geo Examples thereof include methyl rail phosphinate, ethyl diorail phosphinate, n-butyl diorail phosphinate, cyclohexyl diorail phosphinate, vinyl diorail phosphinate, phenyl diol phosphinate and the like.

Examples of monocarboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, hexanoic acid, heptanic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, octadecanoic acid, docosanoic acid, hexacosanoic acid, octadecenoic acid, and the like. Monocarboxylic acids such as docosenoic acid and isooctadecanoic acid, alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid, aromatic monocarboxylic acids such as benzoic acid and methylbenzenecarboxylic acid, hydroxypropionic acid, hydroxyoctadecanoic acid and hydroxyoctadecene. Examples thereof include hydroxyaliphatic monocarboxylic acids such as acids and sulfur-containing aliphatic monocarboxylic acids such as alkylthiopropionic acids.

Examples of sulfonic acids include alkyl sulfonic acids, benzene sulfonic acids, naphthalene sulfonic acids, anthraquinone sulfonic acids, camphor sulfonic acids and derivatives thereof. These sulfonic acids may be monosulfonic acid, disulfonic acid or trisulfonic acid. Examples of the derivative of benzenesulfonic acid include phenolsulfonic acid, styrenesulfonic acid, toluenesulfonic acid, dodecylbenzenesulfonic acid and the like. Examples of the derivative of naphthalene sulfonic acid include 1-naphthalene sulfonic acid, 2-naphthalene sulfonic acid, 1,3-naphthalenedisulfonic acid, 1,3,6-naphthalentrisulfonic acid, 6-ethyl-1-naphthalenesulfonic acid and the like. Can be mentioned. Examples of the derivative of anthraquinone sulfonic acid include anthraquinone-1-sulfonic acid, anthraquinone-2-sulfonic acid, anthraquinone-2,6-disulfonic acid, 2-methylanthraquinone-6-sulfonic acid and the like.

Examples of sulfinic acids include alkansulfinic acid such as ethanesulfinic acid, propanesulfinic acid, hexanesulfinic acid, octansulfinic acid, decanesulfinic acid and dodecanesulfinic acid, and alicyclic sulfinic acid such as cyclohexanesulfinic acid and cyclooctanesulfinic acid. Acids; examples include aromatic sulfinic acids such as benzenesulfinic acid, o-toluenesulfinic acid, p-toluenesulfinic acid, ethylbenzenesulfinic acid, decylbenzenesulfinic acid, dodecylbenzenesulfinic acid, chlorbenzenesulfinic acid, and naphthalinsulfinic acid. ..

Examples of carbonates include dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, dibutyl carbonate, dihexyl carbonate, dioctyl carbonate, diphenyl carbonate, methylethyl carbonate, methylphenyl carbonate, ethylphenyl carbonate, butylphenyl carbonate, ditril carbonate and the like. Be done.

These may be used alone or in combination of two or more.

The polyphenylene ether-based resin is generally available as a powder.
The particle size of the polyphenylene ether-based resin is preferably 1 to 1000 μm, more preferably 10 to 700 μm, and even more preferably 100 to 500 μm.
The average particle size of the polyphenylene ether-based resin powder is preferably 1 μm or more from the viewpoint of handleability during processing, and is preferably 1000 μm or less from the viewpoint of suppressing the generation of unmelted matter during melt-kneading.
The average particle size of the polyphenylene ether-based resin powder can be measured by, for example, a laser particle size meter.

In the thermoplastic resin composition of the present embodiment, the content of the component (A) in 100% by mass of the thermoplastic resin composition is 30 to 90% by mass, preferably 40 to 80% by mass, preferably 45 to 40% by mass. It is more preferably 75% by mass. When the content of the component (A) is 90% by mass or less, the balance between molding fluidity and weathering discoloration is excellent, and when it is 30% by mass or more, the mechanical strength, flame retardancy and electrical properties are excellent.

<(B) Polyolefin resin>
The thermoplastic resin composition of the present embodiment contains (B) a polyolefin resin. By containing (B) a polyolefin resin and (C) titanium oxide described later, the light discoloration resistance is improved. Although the detailed mechanism is not clear, it is considered that the light discoloration resistance can be improved by forming a polyolefin skin layer in which titanium oxide is dispersed on the outermost surface of the thermoplastic resin composition.

Examples of the (B) polyolefin resin used in the present embodiment include low-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, and ethylene-octene co-weight. Examples thereof include a coalescence or an ethylene-acrylic acid ester copolymer. Of these, low-density polyethylene, polypropylene, and high-density polyethylene are preferable. The lower the crystallinity of the polyolefin, the better the compatibility with the elastomer and the impact resistance when the composition contains the elastomer, as well as the co-continuity of the polyolefin / elastomer on the surface of the molded product. It becomes easier to form a phase, and a balance between weather discoloration resistance and impact resistance can be achieved with a smaller amount of polyolefin.

The melt flow rate (MFR) of the component (B) is preferably 0.1 to 50 g / 10 minutes, more preferably 2.0 to 25 g / 10 as measured at a cylinder temperature of 230 ° C. according to ASTM D-1238. Minutes.

The mass ratio ((A) / (B)) of the component (A) to the component (B) is 99/1 to 70/30, more preferably 99/1 to 80/20, and even more preferably.
By setting the content ratio of the component (B) to the component (A) to (A) / (B) = 99/1 or more, it becomes easy to form a polyolefin layer on the surface of the molded product, and the light discoloration resistance is improved. By setting (A) / (B) = 70/30 or less, the polyphenylene ether (A) becomes a continuous phase, and the mechanical strength and heat resistance are improved.

In the thermoplastic resin composition of the present embodiment, the content of the component (B) in 100% by mass of the thermoplastic resin composition is preferably 0.3 to 25% by mass, preferably 1.5 to 15% by mass. It is more preferably present, and even more preferably 2.5 to 10% by mass.

<(C) Titanium oxide>
The thermoplastic resin composition used in this embodiment contains (C) titanium oxide. By containing the component (C), a resin composition having excellent light discoloration resistance can be obtained.

The primary particle size of the component (C) is preferably 0.01 to 1.0 μm, more preferably 0.05 to 0.8 μm, still more preferably, from the viewpoint of the balance between dispersibility and surface activity. It is 0.1 to 0.5 μm.

The component (C) may contain at least one of a hydrous oxide such as aluminum, magnesium, zirconia titanium, tin and / or a higher fatty acid salt such as an oxide or stearic acid or an organic silicon compound as a surface treatment agent.

The component (C) can be produced by a dry method or a wet method. The crystal structure of (C) titanium oxide may be either a rutile type or an anatase type, but the rutile type is preferable from the viewpoint of the thermal stability of the thermoplastic resin composition used in the present embodiment.

As the component (C), it is preferable to use a master batch previously compounded with the polyolefin resin (B) as a raw material. By using the masterbatch raw material, a large amount of the component (C) is dispersed in the (B) polyolefin resin, and the concentration of titanium oxide near the surface of the molded product can be increased.

(B) The mass ratio (B) / (C) of (C) titanium oxide to the polyolefin resin is 50/50 to 5/95, preferably 45/55 to 10/90, and more preferably 40/60. It is ~ 12/88, more preferably 35/65 ~ 15/85.
By setting the content ratio of the component (C) to the component (B) to (B) / (C) = 50/50 or more, the light discoloration resistance is improved and (B) / (C) = 5/95 or less. Therefore, the balance between light discoloration resistance and mechanical strength is excellent.

In the thermoplastic resin composition of the present embodiment, the content of the component (C) in 100% by mass of the thermoplastic resin composition is preferably 0.7 to 45% by mass, preferably 3.5 to 35% by mass. It is more preferably present, and more preferably 6.0 to 28% by mass.

<(D) Styrene resin>
The resin composition of the present embodiment can be blended with (D) a styrene-based resin for the purpose of adjusting heat resistance and molding fluidity. In addition, in this specification, what is included in the range of (E) elastomer described later is not included in (D) styrene resin. The styrene-based resin (D) is not particularly limited, and known ones can be used, and a homopolymer of a styrene-based compound; a styrene-based compound and a compound that can be copolymerized with the styrene-based compound can be used as a rubbery polymer. Polymers obtained by polymerization in the presence or absence; and the like.

The styrene-based compound is not particularly limited, and examples thereof include styrene, α-methylstyrene, 2,4-dimethylstyrene, monochlorostyrene, p-methylstyrene, p-tert-butylstyrene, and ethylstyrene. Of these, styrene is preferable from the viewpoint of practicality of raw materials.
Examples of the compound that can be copolymerized with a styrene compound include methacrylic esters such as methyl methacrylate and ethyl methacrylate; unsaturated nitrile compounds such as acrylonitrile and methacryl nitrile; acid anhydrides such as maleic anhydride; and the like. Be

As the (D) styrene-based resin, polystyrene is preferable from the viewpoint of miscibility with polyphenylene ether. Of these, rubber-reinforced polystyrene is preferable from the viewpoint of improving impact resistance, and general purpose polystyrene is preferable from the viewpoint of improving the appearance of molded products.
Examples of the rubber-reinforced polystyrene include a polymer obtained by polymerizing a styrene-based compound and a compound copolymerizable with the styrene-based compound in the presence of a rubbery polymer.
In the rubber-reinforced polystyrene, the amount of the compound copolymerizable with the styrene compound is 20% by mass or less with respect to the total amount of the styrene compound and the compound copolymerizable with the styrene compound is 100% by mass. Is preferable, and more preferably 15% by mass or less.
The rubbery polymer is not limited to the following, and is, for example, a conjugated diene rubber, a copolymer of a conjugated diene and an aromatic vinyl compound, an ethylene-propylene copolymer rubber, polybutadiene, and a styrene-butadiene random copolymer. Examples thereof include coalesced and styrene-butadiene block copolymers, and rubber components obtained by partially or almost completely hydrogenating them.
Examples of the rubber-reinforced polystyrene include high-impact polystyrene (HIPS), and high-impact polystyrene using a styrene-butadiene block copolymer as a rubber polymer is suitable.
Two types of rubber particles of the rubbery polymer constituting HIPS include salami structure (multi-cell structure) and polystyrene core (single-cell structure).
The above-mentioned "salami structure" means that rubber particles (salami sausage cross-sectional shape) are dispersed in a polystyrene matrix, and a plurality of polystyrene particles are incorporated in a honeycomb shape in the rubber particle phase having a thin outer layer. It is a structure.
The above-mentioned "polystyrene core" is a core-shell structure in which rubber particles having a single cell structure are dispersed in a polystyrene matrix.
The rubber-reinforced polystyrene can be produced by a lumpy polymerization method or a lumpy suspension polymerization method, and the morphology of the rubber particles can be controlled by controlling the stirring state in the polymerization step, the mixed state at the time of producing the rubber particles, and the like.

The content of the (D) styrene-based resin in the resin composition of the present embodiment is preferably 0 to 70% by mass, preferably 5 to 50% by mass, based on the resin composition (100% by mass). More preferably, it is more preferably 10 to 40% by mass. The styrene-based resin (D) is preferably blended from the viewpoint of improving the molding fluidity of the resin composition. Further, from the viewpoint of maintaining sufficient heat resistance, the content of the (D) styrene resin is preferably 70% by mass or less.

<(E) Elastomer>
(E) Elastomer can be further added to the resin composition of the present embodiment for the purpose of improving impact resistance and the like.

As the component (E), a known component can be used, but from the viewpoint of (A) miscibility with the polyphenylene ether and heat resistance, a block co-weight having a styrene block and a hydrogenated conjugated diene compound block. Elastomers containing coalescing (hereinafter also referred to as "styrene block-hydrogenated conjugated diene compound block copolymer") are preferable.

From the viewpoint of thermal stability, the conjugated diene compound block is preferably hydrogenated at a hydrogenation rate of 50% or more, more preferably hydrogenated at 80% or more, and further preferably hydrogenated at 95% or more. It is added.

Examples of the conjugated diene compound block include, but are not limited to, polybutadiene; polyisoprene; poly (ethylene / butylene); poly (ethylene / propylene) and vinyl-polyisoprene; and the like. The conjugated diene compound block may be used alone or in combination of two or more.

The mode of arrangement of the repeating units constituting the block copolymer may be a linear type or a radial type. Further, the block structure composed of the polystyrene block and the rubber intermediate block may be any of type 2, type 3 and type 4. Among them, a three-type linear type block copolymer having a polystyrene-poly (ethylene / butylene) -polystyrene structure is preferable from the viewpoint of sufficiently exerting a desired effect in the present embodiment. The conjugated diene compound block may contain butadiene units in a range not exceeding 30% by mass.

The styrene block-hydrogenated conjugated diene compound block copolymer that can be used in the present embodiment preferably has a weight average molecular weight Mw in the range of 45,000 to 300,000, more preferably 55,000 to 280000, from the viewpoint of improving impact resistance. It is even more preferably 70,000 to 250,000. From the viewpoint of imparting sufficient impact resistance, the weight average molecular weight is preferably 50,000 or more, and from the viewpoint of fluidity, appearance retention, and miscibility of the molded product, it is preferably 300,000 or less.

The amount of bound styrene of the styrene block-hydrogenated conjugated diene compound block copolymer that can be used in the present embodiment is preferably in the range of 20 to 80% by mass, more preferably 30 to 60% by mass, and further. More preferably, it is in the range of 30 to 45% by mass. From the viewpoint of miscibility, the amount of bound styrene of the styrene block-hydrogenated conjugated diene compound block copolymer is preferably 20% by mass or more, and preferably 80% by mass or less from the viewpoint of imparting impact resistance.

The content of the (E) elastomer that can be used in the resin composition of the present embodiment is preferably in the range of 1 to 25% by mass, more preferably 3 to 20 in 100% by mass of the resin composition. It is in the range of% by mass, more preferably 5 to 15% by mass. The content of the elastomer (E) is preferably 1% by mass or more from the viewpoint of obtaining more excellent impact resistance, and preferably 25% by mass or less from the viewpoint of heat resistance and rigidity retention.

<(F) Flame Retardant>
The resin constituting the power receiving / receiving component of the present embodiment preferably contains (F) a flame retardant in addition to the above-mentioned components. (F) The flame retardant is not particularly limited, and halogen-based flame retardants, inorganic flame retardants, silicone compounds, organic phosphorus compounds and the like can be used, but inorganic flame retardants, silicone compounds and organic compounds can be used. It is preferably at least one selected from the group consisting of phosphorus compounds and the like.

Examples of the inorganic flame retardant include alkali metal hydroxides such as magnesium hydroxide and aluminum hydroxide containing crystalline water, which are generally used as flame retardants for synthetic resins, alkaline earth metal hydroxides, and zinc borate. Examples thereof include a compound and a zinc phosphate compound.

Examples of the silicone compound include organopolysiloxane and modified products containing organopolysiloxane, which may be liquid or solid at room temperature. The skeleton structure of the organopolysiloxane may be either a linear structure or a branched structure, but it is preferable to include a branched structure or a three-dimensional structure due to having a trifunctional or tetrafunctional structure in the molecule. Examples of the bonding group of the main chain and the branched side chain include hydrogen or a hydrocarbon group, preferably a phenyl group, a methyl group, an ethyl group and a propyl group, but other hydrocarbon groups may be used. not. As the terminal bonding group, any of -OH, an alkoxy group, or a hydrocarbon group is used.

Silicone compounds generally used as flame retardants include four types of siloxane units (M unit: R ₃ SiO _0.5 , D unit: R ₂ SiO _1.0 , T unit: RSiO _1.5 , Q unit: SiO ₂ ). A polymer obtained by polymerizing any one of _0.0 ) can be mentioned. The preferred organopolysiloxane used in the present embodiment contains 60 mol% or more, more preferably 90 mol of the siloxane unit (T unit) represented by the formula RSiO _1.5 in the total amount of the four siloxane units. % Or more, particularly preferably 100 mol%, and in all the silicone compounds used, at least 60 mol%, more preferably 80 mol% or more of the bound hydrocarbon groups in all the siloxane units represented by R have phenyl groups. Have. As these organopolysiloxanes, modified silicones in which the binding group is substituted with an amino group, an epoxy group, a mercapto group or another modifying group are also used. Further, a modified product obtained by chemically adsorbing or physically adsorbing organopolysiloxane to an inorganic filler such as silica or calcium carbonate can also be used.

Examples of the organic phosphorus compound include a phosphate ester compound and a phosphazene compound. The phosphoric acid ester compound is added to improve the flame retardancy, and any organic phosphoric acid ester generally used as a flame retardant can be used.
Specific examples of the phosphate ester compound include triphenyl phosphate, trisnonylphenyl phosphate, resorcinol bis (diphenyl phosphate), resorcinol bis [di (2,6-dimethylphenyl) phosphate], 2,2-bis {4- [ Examples thereof include bis (phenoxy) phosphoryloxy] phenyl} propane and 2,2-bis {4- [bis (methylphenoxy) phosphoryloxy] phenyl} propane, but the present invention is not limited thereto.

In addition to the above, phosphorus-based flame retardants include, for example, phosphorus such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, tricresyl phosphate, cresylphenyl phosphate, octyldiphenyl phosphate, and diisopropylphenyl phosphate. Ester-based flame retardant, diphenyl-4-hydroxy-2,3,5,6-tetrabromobenzylphosphonate, dimethyl-4-hydroxy-3,5-dibromobenzylphosphonate, diphenyl-4-hydroxy-3 , 5-Dibromobenzyl phosphate, Tris (chloroethyl) phosphate, Tris (dichloropropyl) phosphate, Tris (chloropropyl) phosphate, Bis (2,3-dibromopropyl) -2,3-dichloropropyl phosphate, Tris (2) , 3-Dibromopropyl) phosphate, and monophosphate ester compounds such as bis (chloropropyl) monooctyl phosphate, hydroquinonyldiphenyl phosphate, phenylnonylphenylhydroquinonyl phosphate, phenyldinonylphenyl phosphate, and aromatic condensed phosphate. Examples include ester compounds.

Among these, aromatic condensed phosphoric acid ester compounds are preferably used because they generate less gas during processing and are excellent in thermal stability.
These aromatic condensed phosphoric acid ester compounds are generally commercially available, and for example, CR741, CR733S, PX200 of Daihachi Chemical Industry Co., Ltd., FP600, FP700, FP800 of ADEKA Corporation, and the like are known.

（一般式（４）及び一般式（５）中、Ｑ_１、Ｑ_２、Ｑ_３及びＱ_４は、各々置換基であって各々独立に炭素数１から６のアルキル基を表し、Ｒ_１３及びＲ_１４は各々メチル基を表し、Ｒ_１５及びＲ_１６は各々独立に水素原子又はメチル基を表す。ｎは１以上の整数であり、ｎ_１及びｎ_２は各々独立に０から２の整数を示し、ｍ_１、ｍ_２、ｍ_３及びｍ_４は各々独立に０から３の整数を示す。） Particularly preferred is the condensed phosphoric acid ester represented by the following general formula (4) or general formula (5).

(In the general formula (4) and the general formula (5), Q ₁ , Q ₂ , Q ₃ and Q ₄ are substituents and each independently represents an alkyl group having 1 to 6 carbon atoms, and R ₁₃ and R ₁₄ represents a methyl group, respectively, and R ₁₅ and R ₁₆ each independently represent a hydrogen atom or a methyl group. N is an integer of 1 or more, and n ₁ and n ₂ each independently represent an integer of 0 to 2. Shown, m ₁ , m ₂ , m ₃ and m ₄ each independently indicate an integer from 0 to 3).

In the condensed phosphoric acid ester represented by the above general formulas (4) and (5), each molecule has n as an integer of 1 or more, preferably an integer of 1 to 3.

Among them, the preferred condensed phosphate ester has m ₁ , m ₂ , m ₃ , m ₄ , n ₁ and n ₂ in the general formula (4) being zero, and R ₉ and R ₁₀ being methyl groups. Condensed phosphate ester, and Q ₁ , Q ₂ , Q ₃ , Q ₄ , R ₉ and R ₁₀ in the general formula (4) are methyl groups, n ₁ , n ₂ are zero, and m ₁ , m ₂ , m 2. It is preferable that m ₃ and m ₄ are condensed phosphoric acid esters having an integer number of 1 to 3, and the range of n is 1 to 3, and in particular, those containing 50% by mass or more of the phosphoric acid ester in which n is 1.

In the present embodiment, the content of the (F) flame retardant varies depending on the required flame retardant level, but is preferably in the range of 5 to 25 parts by mass with respect to 100 parts by mass of the (A) polyphenylene ether-based resin. Yes, more preferably in the range of 5 to 20 parts by mass, and even more preferably in the range of 10 to 25 parts by mass. (F) When the content of the flame retardant is 5 parts by mass or more, the flame retardancy is excellent, and when the content is 25 parts by mass or less, the flame retardant is sufficient and the heat resistance can be maintained.

[Other ingredients]
The resin composition of the present embodiment further comprises an antioxidant, an ultraviolet absorber, and hydrolysis suppression within a range that does not significantly reduce the heat resistance, mechanical properties, surface appearance, photodiscoloration resistance, etc. of the molded product. It may contain other components other than the components (A) to (F) such as an agent, an antistatic agent, a lubricant, a mold release agent, a strengthening agent, and an acid.

The content of the above other components in the thermoplastic resin composition of the present embodiment is in the range of 0.001 to 4.0% by mass with respect to the resin composition (100% by mass). It is preferably more preferably 0.01 to 2.0% by mass, and even more preferably in the range of 0.1 to 1.0% by mass. From the viewpoint of exhibiting a sufficient addition effect, it is preferably 0.001% by mass or more, and from the viewpoint of sufficient appearance and retention of physical properties of the molded product, it is preferably 4.0% by mass or less.

For the purpose of improving mechanical strength, the resin composition of the present embodiment may contain an inorganic filler as a strengthening agent as another component. The inorganic filler as a reinforcing agent is generally used for reinforcing a thermoplastic resin, and examples thereof include glass fiber, carbon fiber, glass flakes, talc, chlorite, and mica.
When an inorganic filler as a reinforcing agent is used as another component, the content of the inorganic filler in the thermoplastic resin composition of the present embodiment is, for example, 50% by mass with respect to the resin composition (100% by mass). It is preferably in the range of 0.5 to 40% by mass, still more preferably 1 to 30% by mass. The inorganic filler is preferably contained from the viewpoint of improving mechanical strength, and the content of the inorganic filler is preferably 50% by mass or less from the viewpoint of sufficient appearance of the molded product and maintenance of molding fluidity.

The content ratio of the components (A) to (F) in the thermoplastic resin composition of the present embodiment is not particularly limited, but from the viewpoint of further exerting the effect of the present embodiment, 100% by mass of the thermoplastic resin composition The total content of the components (A) to (F) is preferably 50% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and 100% by mass. There may be.

Further, when an inorganic filler as a reinforcing agent is used as another component, the thermoplastic resin composition of the present embodiment is the same as that of the thermoplastic resin composition excluding the inorganic filler in an amount of 100 parts by mass. The total content of the components A) to (F) can be 90 parts by mass or more, 95 parts by mass or more, 98 parts by mass or more, and 100 parts by mass. ..

[Manufacturing method of thermoplastic resin composition]
The thermoplastic resin composition of the present embodiment contains the above-mentioned (A) component, (B) component, (C) component, and any (D) component, (E) component, (F) component, and other components. It can be produced by melt-kneading by appropriately adjusting the conditions of melt-kneading.

In the method for producing the resin composition of the present embodiment, various melt kneaders, kneading extruders, and the like can be used. As the melt kneader and the kneading extruder, a known kneader can be used. For example, an extruder such as a multi-screw extruder such as a single-screw extruder or a twin-screw extruder; roll, kneader, brabender plast graph. , A heating / melting kneader such as a Banbury mixer; and the like. Of these, a twin-screw extruder is preferable.

Regarding the conditions for melt-kneading the above-mentioned component (A), (B) component, (C) component and any component for producing the above resin composition, a resin composition capable of sufficiently exerting the desired effect of the present embodiment. From the viewpoint of obtaining a large amount of material and stably, it is preferable to use a twin-screw extruder having a screw diameter of 25 to 90 mm.

The extruded resin temperature is preferably 240 to 360 ° C, more preferably 260 to 350 ° C, and even more preferably 280 to 330 ° C. The extruded resin temperature is preferably 240 ° C. or higher from the viewpoint of sufficient compatibility of the constituent components, and preferably 360 ° C. or lower from the viewpoint of maintaining sufficient mechanical properties, imparting light resistance, and extrudability.

As the supply position of each raw material, the component (A) and the optional components (D) and (E) are placed in the barrel 1 on the upstream side of the flow direction of the twin-screw extruder during melt-kneading. It is supplied from the supply port, and then any (F) component is fed from the injection nozzle to the side of the extruder from the second (liquid) supply port on the downstream side of the first supply port using a gear pump, and further ( The first method of supplying the component B) and the component (C) from the third supply port on the downstream side of the second supply port, or the component (A), the component (B), the component (C), any of them. Any of the second methods of charging the components (D) and (E) from the first supply port and charging any component (F) from the second supply port can be selected. The first method is more preferable from the viewpoint that the component (B) easily forms a skin layer on the surface of the molded product.

It is more preferable that the component (B) and the component (C) are extruded and kneaded in advance at a ratio of (B) / (C) of 50/50 to 5/95. When the component (B) and the component (C) are extruded and kneaded in advance, the component (C) is more dispersed in the component (B) and the component (B) forms a skin layer on the surface of the molded product. This is because the component (C) can be unevenly distributed near the surface at the same time, and the light discoloration resistance is improved.

In the screw configuration of the twin-screw extruder, when the total barrel length is 100%, the unmelted mixing zone is preferably 45 to 75% from the upstream side of the barrel, and more preferably 60 to 70%. preferable.

As a suitable molded product in the present embodiment, since it has excellent light discoloration resistance, heat resistance, and mechanical strength, it can be used in various applications such as electronic parts, automobiles, home appliances, office machines, and industrial products. However, the housing of the communication device and peripheral members are particularly preferable.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to these Examples.

The methods for measuring physical properties and raw materials used in Examples and Comparative Examples are shown below.

[Measurement method of physical properties]
(1) Deflection temperature under load (DTUL)
The pellets of the resin composition were dried in a hot air dryer at 90 ° C. for 2 hours. The dried resin composition was set to a cylinder temperature of 320 ° C. and a mold temperature of 90 ° C. by an injection molding machine (manufactured by Toshiba Machine Co., Ltd., EC75SXII) equipped with an ISO physical characteristic test piece mold, and ISO3167, multipurpose test piece A. A dumbbell molded piece of the mold was molded. Using a test piece of 80 mm × 10 mm × 4 mm produced by cutting the obtained molded piece, the deflection temperature under load (° C.) was measured by the flatwise method at 1.82 MPa in accordance with ISO75.
As an evaluation standard, it was judged that the heat resistance was high when the temperature was 100 ° C. or higher.

(2) Tensile strength (TS)
Using the ISO3167 and multipurpose test piece A type dumbbell molded piece prepared in (1) above, the tensile strength (MPa) was measured at 23 ° C. and a test speed of 5 mm / min, and the average value of 5 pieces was measured. Asked.
As an evaluation standard, it was determined that the higher the average value of the measured values of the tensile strength, the better the mechanical properties, and it was determined that the resin composition of the present embodiment was particularly desirable when it was 50 MPa or more. ..

(3) Light discoloration resistance After drying the pellets of the obtained resin composition at 100 ° C for 2 hours, the EC75SXII type injection molding machine manufactured by Toshiba Machine Co., Ltd. (cylinder temperature to 300 ° C, mold temperature to 90 ° C). The color plate was molded in the setting). The obtained molded piece was set in a sunshine weather meter (Dew Cycle Sunshine Super Long Life Weather Meter, model: WEL-SUN-DCH type) manufactured by Suga Test Instruments Co., Ltd., with a black panel temperature of 65 ° C and a water spray for 500 hours. After irradiation, the degree of discoloration of each test plate was measured using a spectrocolorimeter (Macbeth Co., Ltd. Macbis Color Eye MS-2020 +), and ΔE was calculated according to the following CIE1976 color difference formula. ΔE of the molded product before the test is ΔE (0), ΔE of the UV-irradiated surface of the molded product after 500 hours is ΔE (500), ΔE (500) −ΔE (0) is used as an index of discoloration, and ΔE (500). When −ΔE (0) was 16 or less, it was judged that the weather resistance was excellent.
[CIE1976 color difference formula]
ΔL ^* = L ^* _-1 -L ^* _-2
Δa ^* = a ^* _-1 -a ^* _-2
Δb ^* = b ^* _-1 -b ^* _-2
ΔE = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2

(4) Morphology The center of the parallel portion of the ISO3167, multipurpose test piece A type dumbbell molded piece produced in (1) above was cut in the MD direction, and the center of the cut surface was adjusted to be smooth using a microtome. Then, for staining, 0.1 g of ruthenium trichloride hydrate, 1 mL of purified water, and 5 ml of sodium hypochlorite were added to the chalet for reaction, and the sample placed on the wire net was placed in the reaction vapor and allowed to stand for 5 minutes. ..
Then, it was set in a scanning electron microscope with the stained surface facing up, and the central portion of the cutting surface was observed at a magnification of 5000. At this time, if the darkest colored phase (PPE) is the sea of the sea island structure, the PPE is the continuous phase, and if the lightly colored phase (polyolefin) is the sea of the sea island structure, the polyolefin is continuous. Judged as a phase.

[raw materials]
The components used in each Example and each Comparative Example are as follows.

[(A) Polyphenylene ether-based resin (PPE)]
A polyphenylene ether obtained by oxidative polymerization of 2,6-dimethylphenol (2,6-xylenol).
The reduced viscosity (ηsp / c) is 0.51 dL / g.
Hydroxy group concentration is 0.88 per 100 units of monomer Residual copper content 0.6% by mass ppm

[(B) Polyolefin resin (PO)]
LDPE: Low density polyethylene (manufactured by Asahi Kasei Corporation, trade name "SUNTEC-LD M2004")
PP: Polypropylene (manufactured by Japan Polypropylene Corporation, product name "NOVATEC-PP MA3"

[(C) Titanium oxide]
TiO ₂ : Rutile type titanium oxide, average particle size 0.21 μm (manufactured by Huntsman Corporation, trade name “R-TC30”)

〔Master Badge〕
MB-1: PP base, TIM ₂ concentration 70% (manufactured by DIC Corporation, trade name "L-11232MPT")
MB-2: LDPE base, TiO ₂ concentration 70% (manufactured by DIC Corporation, trade name "L-11186MPT")
MB-3: HDPE base, TiO ₂ concentration 60% (manufactured by DIC Corporation, trade name "UF-12766AA")
MB-4: PS base, TIM ₂ concentration 50% (manufactured by DIC Corporation, trade name "PS-F1130 1")

[(D) Styrene resin]
GPPS: General Purpose Polystyrene (manufactured by PS Japan Corporation, product name "685")

[(E) Elastomer]
SEBS: Polystyrene-poly (ethylene-butylene) -polystyrene copolymer (manufactured by TSPC, trade name "TAIPOL6151")

[(F) Flame Retardant]
Flame Retardant: Bisphenol A Condensed Phosphate Ester (manufactured by Daihachi Chemical Co., Ltd., trade name "CR-741")

[Other ingredients]
Mica: Mica (manufactured by Kuraray Co., Ltd., product name "Suzolite Mica 200HK")
MAH: Maleic anhydride (manufactured by NOF CORPORATION, trade name "CRYSTAL MAN AB")
GF: Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., trade name "ECS03T-249")

[Examples 1 to 6, 9 to 12, Comparative Examples 2, 4, 6]
Each component was melt-kneaded using a twin-screw extruder (ZSK-25: manufactured by Coperion (Germany)). Specifically, when the cylinder temperature is set to 280 ° C. in the front stage / 220 ° C. in the rear stage and melt-kneading, the component (A), the component (B), the component (C), the component (D), and the component (E) are used. Other components were supplied at the contents shown in Table 1 from the first supply port on the barrel 1 on the upstream side with respect to the flow direction of the extruder.
Then, the flame retardant as the component (F) was fed from the injection nozzle to the side of the extruder from the second (liquid) supply port on the downstream side of the first supply port with the content shown in Table 1 using a gear pump.
Further, the component (B), the component (C), the component (D) (all in the masterbatch), and other components were fed from the third supply port on the downstream side of the second supply port, and the strand was extruded. .. The screw rotation speed at this time was set to 300 rotations / minute, and the discharge amount was set to 15 kg / h.
In addition, an opening (vent) was provided in the cylinder block, and residual volatilization was removed by suction under reduced pressure. The degree of decompression (pressure) at this time was 0.08 MPa.
The strands extruded from the die were cooled and continuously cut with a cutter to obtain resin composition pellets having a length of about 3 mm and a diameter of 3 mm.
The above-mentioned various evaluations were carried out using the obtained resin composition pellets. The evaluation results are shown in Table 1 below.

[Examples 7 and 8, Comparative Examples 1, 3 and 5]
Each component was melt-kneaded using a twin-screw extruder (ZSK-25: manufactured by Coperion (Germany)). Specifically, when the cylinder temperature is set to 280 ° C. in the front stage / 220 ° C. in the rear stage and melt-kneading is performed, the components (A), (B), (C) ((B), and (C)) are used. , (D) component, (E) component are supplied from the first supply port in the barrel 1 on the upstream side with respect to the flow direction of the extruder at the contents shown in Table 1.
Then, the flame retardant as the component (E) is fed from the injection nozzle to the side of the extruder from the second (liquid) supply port on the downstream side of the first supply port with the content shown in Table 1 using a gear pump. The strands were extruded. The screw rotation speed at this time was set to 300 rotations / minute, and the discharge amount was set to 15 kg / h.
In addition, an opening (vent) was provided in the cylinder block, and residual volatilization was removed by suction under reduced pressure. The degree of decompression (pressure) at this time was 0.08 MPa.
The strands extruded from the die were cooled and continuously cut with a cutter to obtain resin composition pellets having a length of about 3 mm and a diameter of 3 mm.
The above-mentioned various evaluations were carried out using the obtained resin composition pellets. The evaluation results are shown in Table 1 below.

As shown in Table 1, it was found from Examples 1 to 12 that a thermoplastic resin composition having an excellent light discoloration resistance and an excellent balance between heat resistance and mechanical strength can be obtained.

According to the present invention, it is possible to provide a polyphenylene ether-based resin composition having high photochromic resistance while maintaining heat resistance and mechanical strength.

Claims (5)

A thermoplastic resin composition containing (A) a polyphenylene ether-based resin, (B) a polyolefin resin, and (C) titanium oxide.
(A) The component forms a continuous layer,
The content of the component (A) in 100% by mass of the thermoplastic resin composition is 30 to 90% by mass.
The mass ratio of the component (A) / component (B) ((A) / (B)) is 99/1 to 70/30.
A thermoplastic resin composition, characterized in that the mass ratio of the component (B) / the component (C) ((B) / (C)) is 50/50 to 5/95. The thermoplastic resin composition according to claim 1, further comprising (D) a styrene resin and / or (E) an elastomer. The thermoplastic resin composition according to claim 1 or 2, wherein the mass ratio ((A) / (B)) of the component (A) / component (B) is 99/1 to 80/20. The thermoplastic resin composition according to any one of claims 1 to 3, wherein the mass ratio ((B) / (C)) of the component (B) / component (C) is 45/55 to 10/90. thing. (F) The thermoplastic resin composition according to any one of claims 1 to 4, further containing a flame retardant.