JP2006143957A - Thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition which is mainly composed of a polyphenylene ether resin and a polypropylene resin, exhibits good external appearances, mechanical strength and solvent resistance, and is particularly excellent in heat ageing resistance. <P>SOLUTION: The thermoplastic resin composition comprises 100 pts.wt. of a resin component comprised of 5-95 wt% of the polyphenylene ether resin (A) and 95-5 wt% of the polypropylene resin (B) and, incorporated therewith, 1-50 pts.wt. of a compatibility-improving agent (C), where the polyphenylene ether resin (A) has a copper content of at most 0.2 ppm and intrinsic viscosity of 0.3-0.6 dL/g. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin composition. More specifically, the present invention can be used in the fields of electric / electronic / OA equipment, automobiles, and other various fields, and has good appearance, mechanical strength, solvent resistance, and particularly heat aging resistance. The present invention relates to an excellent thermoplastic resin composition.

  Polyphenylene ether resins are excellent in mechanical strength, heat resistance, electrical characteristics, dimensional stability, etc., and are therefore widely used in various applications such as electrical / electronic parts, OA equipment parts, automotive parts and the like. However, since it is an amorphous resin, it has the disadvantage of poor solvent resistance, and is currently difficult to use for applications where oil or solvent adheres to or comes into contact. Polypropylene resin, on the other hand, is inexpensive and lightweight, has excellent fluidity and solvent resistance, and is very widely used in various applications such as automotive parts such as bumpers, sheets and films. However, it is inferior to polyphenylene ether resin in terms of mechanical strength and heat resistance. In various applications such as electrical / electronic parts, OA equipment parts, automotive parts, etc., design diversification, miniaturization, weight reduction, and thinning are progressing, and the environmental temperature at which resin parts are used The demand for resin materials, such as appearance, fluidity, mechanical strength, solvent resistance, and heat aging resistance, has been increasing year by year.

  Therefore, a polymer blend that takes advantage of both advantages, that is, a composition that combines the strength and heat resistance of polyphenylene ether resin with the solvent resistance and fluidity of polypropylene resin has been proposed. For example, Patent Document 1 and Patent Document 2 disclose a resin composition having excellent solvent resistance and moldability by adding a specific hydrogenated block copolymer to a resin composition comprising a polyphenylene ether resin and a polyolefin resin. It is disclosed that a product is obtained. Patent Documents 3 and 4 disclose resin compositions having excellent compatibility, rigidity, heat resistance, and solvent resistance composed of polyphenylene ether, polyolefin, and a specific hydrogenated block copolymer. Further, Patent Document 5 discloses a resin composition excellent in a balance of physical properties such as heat resistance, rigidity, impact resistance, weld strength, and the like, comprising a polyolefin resin, a polyphenylene ether resin, a specific functional compound, and a specific diamine compound. A manufacturing method is disclosed. However, any of the resin compositions disclosed in Patent Document 1 to Patent Document 5 described above have a large decrease in heat aging resistance, particularly elongation at break, which becomes a problem when used in a high-temperature atmosphere over a long period of time. It was not satisfactory. In Patent Document 6, a composition containing two specific polypropylene resins having different properties, polyphenylene ether, and a selective hydrogenated block copolymer in which a conjugated diene compound has a specific vinyl bond improves delamination. And improving the toughness reduction after thermal history. The thermoplastic resin composition described in Patent Document 6 is certainly excellent in oil resistance, chemical resistance, heat resistance, impact resistance, and rigidity, but has a large elongation at break by treatment in a relatively short time at high temperature. However, it was not satisfactory as a heat-resistant material.

US Pat. No. 4,863,997 JP-A-4-183748 Japanese Patent Laid-Open No. 5-70679 JP-A-6-136202 JP 2003-221451 A Japanese Patent Laid-Open No. 9-12800

  The object of the present invention is to reduce the mechanical strength such as elongation at break even when treated in a high temperature atmosphere for a long time while taking advantage of the resin composition mainly composed of polyphenylene ether resin and polypropylene resin as described above. Is to provide a thermoplastic resin composition having a small size and excellent heat aging resistance.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have reduced the content of copper, which is an impurity in the polyphenylene ether resin, and thereby have thermoplasticity mainly composed of polyphenylene ether resin and polypropylene resin. The resin composition has excellent mechanical strength, and it has been found that even when treated in a high temperature atmosphere for a long time, the mechanical strength such as elongation at break is small and the heat aging resistance is excellent. Completed the invention. That is, the gist of the present invention is that the compatibility improver (C) is added to 100 parts by weight of the resin component comprising 5 to 95% by weight of the polyphenylene ether resin (A) and 95 to 5% by weight of the polypropylene resin (B). 50 parts by weight of a thermoplastic resin composition, characterized in that the polyphenylene ether resin (A) has a copper content of 0.2 ppm or less and an intrinsic viscosity of 0.3 to 0.6 dl / g. A thermoplastic resin composition.

  Molded articles obtained from the thermoplastic resin composition of the present invention having a reduced copper content in polyphenylene ether have good appearance, mechanical strength and solvent resistance, and are particularly excellent in heat aging resistance, in a high temperature atmosphere. Even when used for a long time, the decrease in mechanical strength such as elongation at break is small. The composition of the present invention is useful as a molding material in a wide range of fields such as electric / electronic / OA equipment, automobiles and the like.

  Hereinafter, the present invention will be described in detail. The polyphenylene ether resin (A) used in the thermoplastic resin composition of the present invention has the following general formula (1):

(In the formula, two R ^{1 s} each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a hydrocarbon oxy group, and two R ^{2 s} each independently represent a hydrogen atom or a carbon atom. A polymer having a structural unit represented by the formula ( ¹ ) to (3), wherein both R ¹ are not hydrogen atoms), and may be a homopolymer or a copolymer. It is necessary that the copper content is 0.2 ppm or less and the intrinsic viscosity is 0.3 to 0.6 dl / g.
Specific examples of the homopolymer include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, and poly (2,6-phenylene). 2,6 such as dipropyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether -Polymers of dialkylene ethers are exemplified, and examples of the copolymer include various 2,6-dialkylphenol / 2,3,6-trialkylphenol copolymers. Of the above, poly (2,6-dimethyl-1,4-phenylene) ether is particularly preferable.

  The production method of the polyphenylene ether resin (A) used in the thermoplastic resin composition of the present invention is not particularly limited. For example, as shown in US Pat. No. 3,306,874, a monomer such as 2 , 6 xylenol can be easily produced by oxidative polymerization in the presence of a catalyst such as a compound of cuprous salt and amine. Specific production methods are shown in the production examples described later.

The polyphenylene ether resin (A) used in the present invention needs to have a copper content of 0.2 ppm or less. The copper content is preferably 0.1 ppm or less. Resin compositions based on polyphenylene ether resin and polypropylene resin using polyphenylene ether resin with a copper content in polyphenylene ether resin (A) exceeding 0.2 ppm are various when used in a high temperature atmosphere. The mechanical properties are greatly lowered, which is not preferable.
The method for obtaining a polyphenylene ether resin having a copper content of 0.2 ppm or less used in the present invention is not particularly limited. Therefore, since the copper component is derived from the catalyst used in the oxidative polymerization reaction, it is effective to remove the copper salt used in the catalyst so that it is preferably 0.2 ppm or less after the oxidative polymerization reaction is completed. is there. The removal method is not particularly limited. For example, an aqueous solution of ethylenediamine tetraacetate that forms copper and a chelate compound is added to a polyphenylene ether solution obtained by an oxidative polymerization reaction and brought into sufficient contact with the aqueous layer. By separating the copper salt, the copper salt can be efficiently removed. If necessary, this operation is repeated until a predetermined copper content is obtained. Alternatively, when polyphenylene ether is separated from the oxidation reaction solution, the copper content is reduced by using a method that adds a substance that improves the separation between the polymer-containing phase and the copper salt-containing phase, or a combination of these. It is preferable to do. After the oxidation reaction is completed, the content of copper in the polyphenylene ether can be reduced by adding a non-solvent such as methanol to the reaction solution to separate the polyphenylene ether and washing with methanol or water without reducing the copper content. It cannot be reduced to 0.2 ppm or less.

The polyphenylene ether resin (A) used in the present invention has an intrinsic viscosity of 0.3 to 0.6 dl / g. In the present invention, the intrinsic viscosity is determined from a value measured at 30 ° C. using chloroform as a solvent, as described in Examples below. If the intrinsic viscosity of the polyphenylene ether resin is less than 0.3 dl / g, the mechanical strength of the thermoplastic resin composition is lowered. If it exceeds 0.6 dl / g, the fluidity is insufficient, and further, the appearance of the molded product is poor. There are things to do.
A method for obtaining a polyphenylene ether resin having an intrinsic viscosity of 0.3 to 0.6 dl / g is not particularly limited, and the reaction conditions of the oxidation polymerization reaction according to a known method, for example, polymerization temperature, polymerization time, catalyst amount, etc. By controlling the above, polyphenylene ether having a desired intrinsic viscosity can be obtained. In the present invention, two or more polyphenylene ether resins having different intrinsic viscosities may be used in combination, and the intrinsic viscosities of the combined resins may be adjusted to be in the above range.

  In the present invention, if necessary, 50% by weight or less of the polyphenylene ether resin (A) may be replaced with polystyrene or rubber-reinforced polystyrene. If the amount of polystyrene or rubber-reinforced polystyrene exceeds 50% by weight, the load deflection temperature is excessively lowered.

  The polypropylene resin (B) used in the thermoplastic resin composition of the present invention is a crystalline resin obtained by polymerizing propylene as a main component, specifically, a propylene homopolymer, propylene as a main component, And copolymers of α-olefins such as ethylene, butene-1, hexene-1, heptene-1, 4-methylpentene-1. The copolymer may be a random copolymer or a block copolymer, but a block copolymer taking a form in which a propylene-α-olefin copolymer is dispersed in a polypropylene polymer is preferable. The crystalline polypropylene resin that is a homopolymer or a copolymer is preferably a propylene homopolymer or a propylene-ethylene block copolymer.

The density of the propylene polymer portion in the crystalline polypropylene resin that is a homopolymer or a copolymer is not particularly limited, but is usually about 0.9 g / cm ^{3 as} measured by JIS K-7112. used. Normally, when using low density polypropylene, the water vapor barrier property is unsatisfactory.

  The composition of the present invention may contain a nucleating agent for the purpose of improving the crystallinity of polypropylene. Typical examples of such nucleating agents include organic nucleating agents such as aromatic carboxylic acid metal salts, sorbitol derivatives, organic phosphates and aromatic amide compounds, and inorganic nucleating agents such as talc. However, the present invention is not limited to these.

  As a method for measuring the density of the crystalline polypropylene resin, if the crystalline polypropylene resin is a homopolymer, a predetermined test piece is formed by compression molding or injection molding of the crystalline polypropylene resin. And can be determined according to the JIS-K-7112 underwater substitution method. When the copolymer is a crystalline polypropylene resin, the propylene homopolymer is extracted at the time of polymerization, or the copolymer is extracted by using a method such as hexane or the like, or by extracting the copolymer with a solvent such as hexane And a method for obtaining the density of the propylene homopolymer portion by the above method. Further, in order to measure the density of the propylene homopolymer portion in the resin composition, the resin composition is extracted using a good solvent of polyphenylene ether such as chloroform and obtained from the remaining crystalline propylene resin by the above method. Can do.

  The melt flow rate of the crystalline polypropylene resin that is a homopolymer or a copolymer is preferably 0.5 to 100 g / 10 min, as measured at 230 ° C. under a load of 2.16 kg, based on JIS K-7210. More preferably, it is 1.0-50 g / 10min. If the melt flow rate is less than 0.5 g / 10 min, the moldability is insufficient, and if it exceeds 100 g / 10 min, the mechanical strength is unsatisfactory.

  The compatibility improver (C) used in the thermoplastic resin composition of the present invention is not particularly limited as long as it improves the compatibility between the polyphenylene ether resin (A) and the polypropylene resin (B). Absent. Preferred compatibility improvers (C) include polystyrene-polypropylene graft copolymers having a compatibility improvement and an impact resistance improving effect, a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene compound polymer block. One or more types of copolymers selected from hydrogenated polymers, and particularly preferred compatibility improvers are a vinyl aromatic compound polymer block and a conjugated diene compound polymer that are also highly effective as impact modifiers. It is a hydrogenated product of a block copolymer comprising blocks.

  The block copolymer in the hydrogenated product of the block copolymer composed of the vinyl aromatic compound polymer block and the conjugated diene compound polymer block is derived from the chain unit A derived from the vinyl aromatic compound and the conjugated diene. A block copolymer having at least one chain unit B, and the arrangement of the units A and B includes a linear structure or a branched structure. Moreover, among these structures, a random chain derived from a random copolymer portion of a vinyl aromatic compound and a conjugated diene may be included in part. Among these, the compatibility improving agent of the present invention is preferably a linear structure, more preferably a triblock structure.

The hydrogenated product of the block copolymer is a block copolymer in which the aliphatic unsaturated group of the unit B derived from the conjugated diene is reduced by hydrogenation, and the hydrogenation rate is 80% or more. That is, the proportion of unsaturated bonds remaining without being hydrogenated is preferably 20% or less, more preferably 10% or less, before hydrogenation. Moreover, you may use together with the block copolymer which is not hydrogenated. As the vinyl aromatic compound in the hydrogenated product of the block copolymer, styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene and the like are preferable, and styrene is preferable. The conjugated diene is preferably 1,3-butadiene, isoprene, or 2-methyl-1,3-butadiene. Specific examples of the block copolymer include a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, and a plurality of these may be used in combination. In the case of styrene, for example, the aromatic vinyl compound unit in the hydrogenated block copolymer is preferably 15 to 75% by weight.

  The ratio of the polyphenylene ether resin (A) to the polypropylene resin (B) in the composition of the present invention is 5/95 when the weight ratio of the polyphenylene ether resin (A) / polypropylene resin (B) is 5/95. It is -95/5, More preferably, it is 10 / 90-70 / 30, Especially preferably, it is 20 / 80-60 / 40. When the polyphenylene ether resin (A) is less than 5% by weight, the heat resistance and rigidity are unsatisfactory, and when the polypropylene resin is less than 5% by weight, the solvent resistance and fluidity are unsatisfactory.

  In the present invention, the compounding ratio of the compatibility improver (C), which improves the compatibility of the polyphenylene ether resin (A) and the polypropylene resin (B) and also has an effect of improving the impact resistance, is determined by the polyphenylene ether resin ( It is 1-50 weight part with respect to a total of 100 weight part of A) and a polypropylene resin (B), Preferably it is 3-40 weight part. When the blending amount of the compatibility improver (C) is less than 1 part by weight, the effect of improving the compatibility and impact resistance is small, and when it exceeds 50 parts by weight, the heat resistance and rigidity are unsatisfactory.

The composition of the present invention contains the above components (A) to (C) as essential components, but other components can be blended within a range not impairing the effects of the present invention. Examples of other components that can be added as necessary include antioxidants, weather resistance improvers, nucleating agents, plasticizers, fluidity improvers, and the like, which are well known for use in thermoplastic resins. Addition of organic fillers, reinforcing agents, inorganic fillers such as glass fiber, talc, mica, kaolin, calcium carbonate, silica, clay and the like is particularly effective for improving rigidity, heat resistance, dimensional characteristics and the like. For practical use, various colorants and their dispersants can be used.
In the present invention, it is also preferable to add a flame retardant in order to impart flame retardancy. As the flame retardant used in the composition of the present invention, various known ones can be used, and are not particularly limited. The amount of the flame retardant is an amount required to obtain a target flame retardant level. It is. Preferably, phosphorus-based, halogen-based, inorganic-based flame retardants, flame retardant aids, and combinations thereof are used, and generally about 1 to 50 parts by weight is blended with 100 parts by weight of the resin component. .

  The method for producing the thermoplastic resin composition of the present invention is not particularly limited, and a known method is employed. For example, a method of kneading the above components with various kneaders such as uniaxial and multiaxial kneaders, Banbury mixers, rolls, Brabender plastograms, etc., and then cooling and solidifying, or a suitable solvent such as hexane, heptane, benzene For example, a solution mixing method in which the above components are added to hydrocarbons such as toluene and xylene and derivatives thereof and the components to be dissolved or the dissolved components and the insoluble components are mixed in a suspended state is used. From the industrial cost, the melt-kneading method is preferable, but it is not limited thereto.

  The molding method of the thermoplastic resin composition of the present invention is not particularly limited, and a molding method generally used in molding a thermoplastic resin composition, for example, injection molding, hollow molding, extrusion molding, sheet molding. Further, molding methods such as thermoforming, rotational molding, and lamination molding can be applied.

The best mode for carrying out the present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
The evaluation method in the following examples and the production method of polyphenylene ether are as follows.
<Evaluation method of polyphenylene ether>

(1) Intrinsic viscosity: 0.5 g of polyphenylene ether as a solution was dissolved in chloroform so that the concentration became 100 ml or more (concentration of 0.5 g / dl or less), and the ratio at different concentrations was measured using an Ubbelohde viscometer at 30 ° C. The intrinsic viscosity was calculated by measuring the viscosity and extrapolating the ratio between the specific viscosity and the concentration to 0.
(2) Copper content: After polyphenylene ether was decomposed with nitric acid, the copper in the residue was quantified by atomic absorption analysis, and the copper content in the polyphenylene ether was calculated.

[Production example of polyphenylene ether (A)]
A 10-liter jacket equipped with a sparger for introduction of oxygen-containing gas at the bottom of the reactor, a stirring turbine blade and baffle, and a reflux condenser with a decanter for separation of condensate at the bottom of the vent gas line at the top of the reactor. An autoclave reactor equipped with 1.4172 g cuprous oxide, 8.5243 g 47% aqueous hydrogen bromide, 16.5277 g N, N-di-n-butylamine, 41.9196 g N, N-dimethyl- n-Butylamine, 3.4139 g of N, N′-di-t-butylethylenediamine, 1.00 g of trioctylmethylammonium chloride and 2770.3 g of toluene were added to prepare an initial charging solution. Next, nitrogen was introduced into the reactor gas phase, and the absolute pressure in the reactor gas phase was controlled to 0.108 MPa.

  Subsequently, a gas made by diluting oxygen with nitrogen and having an absolute pressure of 0.108 MPa and an oxygen concentration of 70% was introduced from a sparger, and thereafter nitrogen was introduced into the reactor gas phase part including during polymerization. During the introduction, the control valve was controlled so that the absolute pressure in the gas phase of the reactor was maintained at 0.108 MPa with nitrogen and the above gas. The gas introduction rate was 3.45 Nl / min. Immediately after starting the introduction of the gas, a solution in which 1100 g of 2,6-dimethylphenol was dissolved in 1056.9 g of toluene was added at a speed at which the whole amount was charged in 30 minutes using a plunger pump. Started. The polymerization temperature was adjusted by passing a heating medium through the jacket so as to maintain 40 ° C. About 140 minutes after the start of gas introduction, nitrogen was introduced instead of the oxygen-containing gas, and 500 g of a 5% aqueous solution of ethylenediaminetetrasodium acetate (sodium EDTA) was added to the reactor and stirred. Thereafter, stirring was continued for 2 hours while controlling with a heat medium so that the temperature of the reaction solution became 70 ° C.

  After the stirring was stopped, the aqueous solution separated by standing was discharged out of the system, and 250 g of pure water was further added to the reaction solution, stirred for 10 minutes, and allowed to stand for 10 minutes, and then the separated aqueous layer was discharged out of the system. . Thereafter, an approximately equal volume of methanol was added to the resulting reaction solution to precipitate polyphenylene ether. The precipitate was collected by filtration, further washed with an appropriate amount of methanol, and then strongly dried at about 140 ° C. for 1 hour to obtain powdered polyphenylene ether (A).

The evaluation results of the obtained polyphenylene ether (A) (hereinafter sometimes abbreviated as PPE (A)) were as follows.
Intrinsic viscosity: 0.48 dl / g
Copper content: less than 0.1 ppm

[Production example of polyphenylene ether (B)]
Although it manufactured similarly to the manufacturing method of the said polyphenylene ether (A), 0.3 g of trioctylmethylammonium chloride was used, and it introduce | transduced nitrogen instead of oxygen-containing gas about 155 minutes after gas introduction start. Only the thing was changed and the powdery polyphenylene ether (B) was obtained.

The evaluation results of the obtained polyphenylene ether (B) (hereinafter sometimes abbreviated as PPE (B)) were as follows.
Intrinsic viscosity: 0.48 dl / g
Copper content: 0.5ppm
<Raw materials other than polyphenylene ether>

(I) Polypropylene resin: manufactured by Nippon Polychem, “Novatech BC5D”, MFR = 3 g / 10 min. The density of the polypropylene polymer portion is 0.9 g / cm ³ (hereinafter sometimes abbreviated as PP).
(ii) Rubber-reinforced polystyrene: A & M Styrene Co., Ltd., trade name “HT478” (hereinafter sometimes abbreviated as HIPS)
(iii) Hydrogenated compound of vinyl aromatic compound-conjugated diene block copolymer: manufactured by Kuraray Co., Ltd., trade name “Septon 2104”, hydrogenated product of styrene-isoprene-styrene copolymer, styrene content 65% by weight (Hereinafter, abbreviated as SEPS)

(iv) Phenol antioxidant: pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], manufactured by Ciba Specialty Chemicals, Inc., trade name “IRGANOX1010” (hereinafter referred to as “IRGANOX1010”) And may be abbreviated as Stabilizer 1).
(v) Phosphite ester stabilizer: 4,4′-tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, Ciba Product name “IRGAFAS P-EPQ” manufactured by Specialty Chemicals (hereinafter sometimes abbreviated as stabilizer 2).

[Method for evaluating thermoplastic resin composition]
(A) Tensile test: According to ASTM-D638. Test temperature 23 ° C.
(B) Flexural modulus test: conforming to ASTM-D790. Test temperature 23 ° C.
(C) Notched Izod impact test: Conforms to ASTM-D256. Test temperature 23 ° C.
(D) Load deflection temperature test: The test was conducted at a load of 0.45 MPa according to ASTM-D648.
(E) Heat aging resistance test: In order to evaluate changes in physical properties when used in a high-temperature atmosphere, it is performed in a gear oven at 80 ° C. for 50 hours (hereinafter abbreviated as treatment condition 1) and 500 hours (hereinafter, treatment). Using the heat-treated test piece (abbreviated as Condition 2), the tensile test, the flexural modulus test, the notched Izod impact test, and the load deflection temperature test were carried out in the above (a) to (d).

[Examples 1-3, Comparative Examples 1-3]
Each component weighed in the proportions shown in Table 1 is uniformly mixed with a tumbler mixer, put into a hopper of a twin screw extruder (screw diameter 30 mm, L / D = 42), cylinder temperature 250 ° C., screw rotation speed The mixture was melt-mixed and pelletized at 400 rpm.
The obtained pellets were dried at 80 ° C. for 2 hours, and then with a Toshiba Machine IS80B type injection molding machine under conditions of a mold temperature of 60 ° C., a cylinder set temperature of 250 to 270 ° C., an injection pressure of 85 MPa, and a molding cycle of 40 seconds. A test piece used for the evaluation test was molded. Using each test piece, the thermoplastic resin composition was evaluated by the above evaluation method, and the results are shown in Table 1.

As is apparent from Table 1, the thermoplastic resin compositions of the present invention shown in Examples 1 to 3 have little decrease in mechanical strength even when used for a long time in a high temperature atmosphere, and the copper content is 0. Compared to the composition of the comparative example using 0.5 ppm of polyphenylene ether, the decrease in elongation at break is particularly small and the heat aging resistance is excellent.

Claims (2)

  Thermoplastic resin in which 1 to 50 parts by weight of compatibility improver (C) is blended with 100 parts by weight of resin component consisting of 5 to 95% by weight of polyphenylene ether resin (A) and 95 to 5% by weight of polypropylene resin (B). A thermoplastic resin composition, wherein the polyphenylene ether resin (A) has a copper content of 0.2 ppm or less and an intrinsic viscosity of 0.3 to 0.6 dl / g. The compatibility improver (C) is a polystyrene-polypropylene graft copolymer, at least one copolymer selected from a hydrogenated product of a block copolymer comprising a vinyl aromatic compound polymer block and a conjugated diene compound polymer block. The thermoplastic resin composition according to claim 1, which is a coalescence.