JP2581160B2 - Thermoplastic resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic resin composition excellent in processability, impact resistance and surface appearance of a molded product.

[Prior art] Thermoplastic polyesters represented by polyethylene terephthalate and polybutylene terephthalate are used as molded products in a wide variety of household electric appliances, electronic equipment parts, automobile parts and the like due to their excellent properties. And has a disadvantage of low impact resistance. For the purpose of remedying this drawback, Japanese Patent Publication No. 58-47419 proposes a method of blending a copolymer comprising ethylene and glycidyl methacrylate, but this composition is inferior in processability and appearance of a molded product. There is a disadvantage that.

[Problems to be Solved by the Present Invention] The present inventors have conducted intensive studies to obtain a resin composition which is excellent in processability, impact resistance and surface appearance of a molded article and can be used in a wide range of applications. By blending a styrene-based polymer-grafted graft copolymer and a rubbery copolymer at a specific ratio to a copolymer mainly composed of olefin units and epoxy group-containing unsaturated compound units It has been found that a thermoplastic resin composition having overall excellent performance can be obtained, and the present invention has been completed based on such findings.

[Means for Solving the Problems] That is, the present invention provides: (a) 9 to 99 parts by weight of a thermoplastic polyester, (b) a copolymer mainly composed of an olefin unit and an epoxy group-containing unsaturated compound unit, and a styrene-based copolymer. A thermoplastic resin composition comprising 0.05 to 30 parts by weight of a graft copolymer obtained by grafting a polymer and (c) 0.95 to 90.5 parts by weight of a rubbery polymer.

A typical example of the thermoplastic polyester of the component (a) used in the present invention is a polyester compound comprising a dicarboxylic acid and a diol compound, and a relatively high molecular weight and substantially linear thermoplastic polymer is preferable. As the dicarboxylic acid used here, Or a derivative thereof, and as Ar, And an alkyl group, a halogen group, an alkoxy group or the like directly added to an aromatic group.

The diol component is represented by HO = (CH ₂ ) _n —OH, and n = 2 to 10 is used.
Preferred are polymeric glycol esters of terephthalic acid and isophthalic acid.

Although these polymers are already commercially available, known production techniques (US Pat. No. 2,465,319,
U.S. Pat. No. 3,047,539).

That is, it can be produced by alcoholysis of a phthalic acid ester with glycol and a subsequent polymerization reaction, and can also be produced by a polymerization reaction of a free phthalic acid or a halide derivative thereof with glycol by heating, and similar production methods. It can also be manufactured by a method.

Preferred thermoplastic polyesters used in the present invention are those composed of a high molecular weight polymeric glycol terephthalate or glycol esoftate having a repeating unit represented by the following formula and a mixture of these esters.

Here, n is preferably an integer of 2 to 10, and particularly preferably 2 to 4 from the viewpoint of physical properties of the composition. Further, a copolymer of terephthalic acid and isophthalic acid containing up to 30% of an isophthalic acid unit can also be suitably used.

Particularly preferred polyesters include poly-ethylene terephthalate and poly-1,4-butylene terephthalate.

Also, branched poly-ethylene terephthalate and branched poly-1,4-butylene terephthalate can be used. Such a branched polymer can contain a small amount of a branching component having at least three ester-forming groups, for example, up to 5 mol% based on terephthalic acid units.

The branching component may form a branch in the polyol unit other than the acid unit of the polyester, or may be a mixture of both. Examples of such branched components include:
Tri- or tetracarboxylic acids such as trimesic acid,
Trimellitic acid, pyromellitic acid and lower alkyl esters thereof and the like, or polyols, preferably tetrols such as pentaerythritol and triols such as trimethylolpropane, or dihydroxycarboxylic acids and hydroxycarboxylic acids and derivatives thereof, such as And dimethyl hydroxyterephthalate.

These branched polyesters are described, for example, in U.S. Pat.
It can be produced by the same production method as the branched poly (1,4-butylene terephthalate) resin described in the specification of 3,404.

The high molecular weight polyesters useful in the practice of the present invention have, for example, at least 0.2 dl / mol as measured as a solution in o-chlorophenol or a mixture of phenol / tetrachloroethane = 60/40 by weight at a temperature of 25-30 ° C. g having an intrinsic viscosity of 0.4 to 2 dl / g.

As the polyester used in the present invention, copolyesters are also useful, for example, U.S. Patent No. 3,651,014,
Segment copolyesters having a large number of repeating ether esters and / or ester units as described in U.S. Pat. Nos. 3,763,109 and 3,766,146 can be suitably used.

The above-mentioned (a) component thermoplastic polyester is one or two kinds.
More than one species may be used. The amount of the thermoplastic polyester used as the component (a) in the thermoplastic resin composition of the present invention is 9 to 99 parts by weight, preferably 40 to 90 parts by weight, more preferably 50 to 90 parts by weight, based on the total amount of the composition. 80 parts by weight.
Particularly preferably, it is 60 to 80 parts by weight.

If the amount is less than 9 parts by weight, the rigidity, workability and surface appearance of the molded product are inferior, and if it exceeds 99 parts by weight, the impact resistance is inferior.

The component (b) of the present invention is a graft copolymer obtained by grafting a styrene-based polymer to a copolymer obtained by copolymerizing a compound mainly composed of an olefin compound and an epoxy group-containing unsaturated compound.

Examples of the olefin used for the main chain copolymer of this component include ethylene, propylene, and butene-1. Ethylene can be suitably used in the present invention, particularly from the viewpoint of good properties of the composition.

As the epoxy group-containing unsaturated compound used for producing the main chain copolymer of this component, a compound having an unsaturated group capable of copolymerizing with an olefin and an epoxy group in one molecule is used.

For example, unsaturated epoxy compounds such as unsaturated glycidyl esters, unsaturated glycidyl ethers, epoxy alkenes and p-glycidyl styrenes represented by the following general formulas (I), (II) and (III) Can be used.

In this formula, R is a C2-C18 hydrocarbon group having an ethylenically unsaturated bond.

In this formula, R is a hydrocarbon group having 2 to 18 carbon atoms which has an ethylenically unsaturated bond, X is -CH ₂ -O-, It is.

In this formula, R is a hydrocarbon group having 2 to 18 carbon atoms having an ethylenically unsaturated bond, and R 'is hydrogen or a methyl group.

Examples of the monomer used in the main chain copolymer of the component (b) of the present invention represented by such a formula include glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, butene carboxylate, allyl glycidyl ether, -Methylallyl glycidyl ether, styrene-p-glycidyl ether, 3,4-
Epoxybutene, 3,4-epoxy-3-methyl-1-butene-1-pentene, 3,4-epoxy-1-butene, 3,4-
Epoxy-3-methylpentene, 5,6-epoxy-1-
Hexene, vinylcyclohexene monoxide, p-glycidylstyrene and the like can be mentioned.

In the present invention, one or more of these can be used.

(B) The weight ratio of the olefin to the epoxy group-containing unsaturated compound in the main chain copolymer in the component, that is, the weight ratio of the olefin component to the epoxy group-containing unsaturated compound is 99.9: 0.1 to 60:40. , Preferably 97: 3 to 70:30.

In addition, the main chain copolymer of the component (b) may optionally have
By other vinyl monomers copolymerizable with the above monomers,
Up to 50 parts by weight, preferably up to 20 parts by weight, more preferably up to 10 parts by weight of the olefin component of the main chain copolymer can be used.

Other vinyl monomers that can be copolymerized herein include aromatic vinyl compounds, vinyl cyanide compounds, carboxyl group-containing unsaturated compounds, acid anhydride group-containing unsaturated compounds, maleimide compounds, (meth) acrylic acid There are an alkyl ester, a hydroxyl group-containing unsaturated compound, an amino group-containing unsaturated compound, an amide group-containing unsaturated compound and the like, and these are used alone or in combination of two or more.

Aromatic vinyl compound As the aromatic vinyl compound used herein, styrene, α-methylstyrene, methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, tribromostyrene, p- Tertiary butyl styrene, ethyl styrene, vinyl naphthalene and the like are preferable, and styrene and α-methyl styrene are preferable. These are used alone or in combination of two or more.

Vinyl cyanide compounds Examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile.

Maleimide compounds Maleimide compounds include maleimide, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, hydroxyphenylmaleimide, N- (P-bromomaleimide). Phenyl) maleimide.

Carboxyl group-containing unsaturated compound Examples of the carboxyl group-containing unsaturated compound used herein include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid and maleic acid, and are preferably acrylic acid and methacrylic acid. is there. These are 1
Used in species or two or more.

Acid anhydride group-containing unsaturated compoundExamples of the acid anhydride group-containing unsaturated compound include maleic anhydride, itaconic anhydride, chloromaleic anhydride, citraconic anhydride, butenyl succinic anhydride, tetrahydrophthalic anhydride, and the like. The preferred unsaturated anhydride is maleic anhydride. These are used alone or in combination of two or more.

Hydroxyl group-containing unsaturated compound The hydroxyl group-containing unsaturated compound is a compound having at least one unsaturated bond (double bond or triple bond) and containing a hydroxyl group. Typical examples thereof include alcohols having a double bond, alcohols having a triple bond, esters of a monovalent or divalent unsaturated carboxylic acid and an unsubstituted dihydric alcohol, and unsubstituted trivalent unsaturated carboxylic acids. Examples of the ester include an ester with an alcohol, an ester with an unsubstituted tetrahydric alcohol, and an ester with an unsubstituted pentahydric or higher alcohol.

Among the hydroxyl compounds used in the present invention, a preferable example of a suitable compound is 3-hydroxy-1.
-Propene, 4-hydroxy-1-butene, cis-4-
Hydroxy-2-butene, trans-4-hydroxy-
2-butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-
5-hydroxy-2-pentene, cis-1,4-dihydroxy-2-butene, trans-1,4-dihydroxy-2
-Butene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxyethyl crotonate, 2,3,4,5,6
-Pentahydroxyhexyl acrylate, 2,3,4,5,6
-Pentahydroxyhexyl methacrylate, 2,3,4,5
-Tetrahydroxypentyl acrylate, 2,3,4,5-
And tetrahydroxypentyl methacrylate.

 These are used alone or in combination of two or more.

Amino group-containing unsaturated compound As the amino group-containing unsaturated compound, the following general formula (Wherein, R ₁ represents hydrogen, a methyl group or an ethyl group, R ₂ represents hydrogen, an alkyl group having 1 to 12 carbon atoms, and 2 to 2 carbon atoms.
12 represents an alkanoyl group, a phenyl group having 6 to 12 carbon atoms, a cycloalkyl group having 6 to 12 carbon atoms, or derivatives thereof. ) At least one of the amino groups or substituted amino groups represented by
Species of vinyl monomers, specific examples of which include aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, aminopropyl methacrylate, phenylaminoethyl methacrylate, and cyclohexylaminoethyl methacrylate Alkyl ester derivatives of acrylic acid or methacrylic acid, vinylamine derivatives such as N-vinyldiethylamine and N-acetylvinylamine, allylamine,
Allylamine derivatives such as methacrylamine and N-methylallylamine, and aminostyrenes such as p-aminostyrene are used. Among them, allylamine, aminoethyl methacrylate, aminopropyl methacrylate, aminostyrene and the like are particularly preferably used because they are economically available on an industrial scale. These unsaturated compounds having an amino group or a substituted amino group are used alone or in combination of two or more.

Amide group-containing unsaturated compound As the amide group-containing unsaturated compound, acrylamide derivatives such as acrylamide and N-methylacrylamide can be used.

(Meth) acrylic acid alkyl ester methyl acrylate, ethyl acrylate propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2
Alkyl acrylates such as ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, and benzyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, and cyclohexyl methacrylate , Dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, benzyl methacrylate and the like, and these are used alone or in combination of two or more. Vinyl acetate is also used as another copolymerizable vinyl monomer. Particularly preferred are ethylene and glycidyl methacrylate copolymers.

The component (b) of the present invention is obtained by grafting a styrene-based copolymer to the main chain copolymer. The styrene-based polymer to be grafted is a polymer composed of an aromatic vinyl compound or a copolymer of an aromatic vinyl compound and another vinyl monomer copolymerizable with the aromatic vinyl compound (provided that ( Excluding alkyl (meth) acrylate).

As the aromatic vinyl compound used here, all of those described above are used. Other copolymerizable vinyl monomers include the above-mentioned vinyl cyanide compound, epoxy group-containing unsaturated compound, maleimide compound, carboxyl group-containing unsaturated compound, acid anhydride group-containing unsaturated compound, and hydroxyl group-containing unsaturated compound. Compounds, amino group-containing unsaturated compounds, amide group-containing unsaturated compounds and the like are all used.

The weight ratio of the main chain copolymer component to the graft component used in the production of the component (b) of the present invention is preferably from 95: 5 to 30:70 by weight.

The component (b) of the present invention can be usually produced by a method of causing a polymer addition reaction of a graft component to a main chain copolymer component or a method of causing a graft polymerization reaction of a graft monomer unit to a main chain polymer. In the actual addition reaction or polymerization reaction, a part of the raw materials blended for grafting is introduced as a graft side chain, and other raw materials are contained in the product as a main chain copolymer and a free polymer. May be present as a mixture.

As the component (b) of the present invention, one in which at least 1% by weight or more of the raw material of the used graft component is introduced into the graft side chain can be used.

Regarding the graft copolymer of the component (b) in the present invention, the entire mixture containing components other than the graft copolymer produced by the above-described production method is regarded as the graft copolymer, and the amount of the composition Has been stipulated.

Examples of the method for producing the component (b) of the present invention include the following methods.

A method of adding a styrene-based polymer having a -O-O- bond in a molecule by a polymer reaction, for example, a polyperoxide and an aromatic vinyl compound polymer or an aromatic compound, or other copolymerizable with an aromatic vinyl compound. A method of grafting a copolymer of the above with a vinyl compound together with an ethylene-epoxy group-containing unsaturated compound copolymer by a radical addition reaction in an extruder or a solution.

A method in which an aromatic vinyl compound or a vinyl compound copolymerizable monomer is polymerized in the presence of an ethylene-epoxy group-containing unsaturated compound copolymer, followed by a graft reaction.

It can be produced by melt-mixing an aromatic vinyl compound or a vinyl compound copolymerizable monomer, for example, polystyrene and an ethylene-epoxy group-containing unsaturated compound copolymer in the presence of a peroxide.

In the graft polymer produced by the above method and the method described above, the distinction between the main chain and the graft side chain is not clear, but in the present invention, the chain of the epoxy-containing copolymer is defined as the main chain regardless of the polymer structure. I do.

A preferred method for producing the component (b) used in the present invention is a method known in the art, for example, polymerization of an aromatic vinyl compound and a polyperoxide at a temperature of 65 ° C. in an inert gas atmosphere, This can be produced by a method of causing a graft reaction to the main chain polymer by the following method (Polymer Transactions, Vol. 44, No. 2, pp. 81-95, 1987).

The molecular weight of the polymer grafted to the component (b) of the present invention is 50,000 to 300,000 (weight average molecular weight in terms of polystyrene).
Preferably, the component (b) itself has a multiphase structure by these grafts in order to achieve the object of the present invention.

The amount of the component (b) used in the thermoplastic resin composition of the present invention is 0.05 to 30 parts by weight, preferably 0.2 to 20 parts by weight, more preferably 0.3 to 10 parts by weight, particularly preferably 0.3 to 10 parts by weight based on the total amount of the composition. Can be compounded in an amount of 0.5 to 10 parts by weight.

If the amount is less than 0.05 part by weight, the impact resistance, the surface appearance of the molded product is poor, and when a pellet composition is obtained by using an extruder, the strand is disturbed and industrial production becomes difficult. If it exceeds, workability is inferior.

Examples of the rubbery polymer as the component (c) of the present invention include diene rubbers such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, and polyisoprene; ethylene-α-olefin copolymer; α-olefin-polyene copolymer, non-diene rubber such as polyacrylate, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, styrene-propylene elastomer,
Styrene-grafted ethylene-propylene elastomer,
Examples include an ethylene ionomer resin and a hydrogenated styrene-isoprene block copolymer.

Such styrene-butadiene block copolymers include AB type, ABA type, ABA taper type, radial teleblock type and the like.

One or more of these rubbery polymers can be used.

Among these rubbery polymers, ethylene-α-olefin copolymers, ethylene-α-olefin-polyene copolymers, and styrene-butadiene block copolymers are preferred in terms of impact resistance, processability, and surface appearance of molded articles. Preferred are polymers, hydrogenated styrene-butadiene block copolymers, and hydrogenated styrene-isoprene block copolymers, and particularly preferred are ethylene-α-olefin copolymers.

The weight ratio of ethylene to α-olefin of the ethylene-α-olefin copolymer used here is 95: 5 to 5: 9.
5, preferably 95: 5 to 20:80, more preferably 92: 8 to
The ratio is 60:40, particularly preferably 85:15 to 70:30.

When the weight ratio of ethylene to α-olefin used in the component (c) of the present invention is in the range of 20:80 to 30:70, the moldability of the composition of the present invention is particularly improved.

Also, from the viewpoint of improving the impact resistance, ethylene and α
-It is desirable to have the olefin weight ratio in the range of 80:20 to 70:25.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the ethylene-α-olefin copolymer used for the component (c) of the present invention is 5 to 200, preferably 5 to 100, and more preferably 5 to 100, from the viewpoint of impact resistance. Is preferably 5 to 50. Mooney viscosity is 10-30
In particular, the impact resistance of the composition is improved.

The cyclohexane-insoluble content of the ethylene-α-olefin copolymer affects the processability and impact resistance of the thermoplastic resin composition of the present invention, and is preferably 50 parts by weight or less.
More preferably, the amount is 5 parts by weight or less.

The α-olefin used herein is an unsaturated hydrocarbon compound having 3 to 20 carbon atoms, for example, propylene, butene-1, pentene-1, hexene-1, heptene-1, 4-methylbutene- 1,4-methylpentene-1 and the like. Particularly preferred is propylene.

The amount of the component (c) used in the thermoplastic resin composition of the present invention is 0.95 to 90.5 parts by weight, preferably 10 to 60 parts by weight, more preferably 20 to 50 parts by weight, and particularly preferably 20 to 50 parts by weight.
40 parts by weight. If it is less than 0.95 parts by weight, impact resistance is poor,
If it exceeds 90.5 parts by weight, the workability and the appearance of the molded product surface are inferior.

In the present invention, by using the component (b) and the component (c) together, it is possible to obtain a composition having high impact resistance, which cannot be obtained by the component (b) alone or the component (c) alone.

In this case, the weight ratio of the component (b) to the component (c) is 1:
It is preferable to select an appropriate value in the range of 99 to 50:50.

The thermoplastic resin composition of the present invention, various extruders, Banbury mixer, kneader, roll, etc., 200 ° C. ~ 350
It can be obtained by kneading each component at a temperature of ° C.

A preferred kneading method is a method using a kneading extruder, and a particularly preferred extruder is a twin-screw co-rotating extruder.

When using the thermoplastic resin composition of the present invention, various fillers can be added.

For example, glass fiber, carbon fiber, metal fiber, glass beads, asbestos, wollastonite, calcium carbonate,
Fillers such as talc, barium sulfate, mica, potassium titanate, fluororesin, and molybdenum disulfide can be used alone or in combination.

Among these fillers, those having a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more are preferable as a fiber shape such as glass fiber and carbon fiber.

These fillers can be used in an amount of 5 to 150 parts by weight based on 100 parts by weight of the thermoplastic resin composition.

In addition, known additives such as a flame retardant, an antioxidant, and a plasticizer can be used. Preferred flame retardants are of the halogen type, for example, brominated polystyrene, brominated polyphenylene ether, brominated epoxy oligomer and the like.

Further polymers depending on the required performance, such as AB
S resin, AS resin, HIPS, polystyrene, polyamide, polyethylene, polypropylene, polycarbonate, polysulfone, polyethersulfone, polyimide, PPS,
Polyetheretherketone, vinylidene fluoride polymer polyphenylether and the like can be appropriately blended.

The thermoplastic resin composition of the present invention can be used as various molded articles by injection molding, sheet extrusion, vacuum molding, heterogeneous molding, foam molding and the like.

Various molded products obtained by the above molding method, utilizing its excellent performance, automobile exterior, interior members and electricity,
It can be used for various electronic parts, housings, etc.

[Examples] The present invention will be described in more detail with reference to examples, but these are all illustrative and do not limit the content of the present invention.

In the following examples, parts and% indicate parts by weight and% by weight, respectively.

(A) of the present invention used in Examples and Comparative Examples of the present invention
The components (b) and (c) are shown below.

1. (a) Ingredient A-1: Polybutylene terephthalate, manufactured by Polyplastics Co., Ltd. Trade name DURANEX XD499 A-2: Polyethylene terephthalate, manufactured by Nippon Unipet Co., Ltd. Unipet RT543 2. (b) Component B-1: ethylene-glycidyl methacrylate (hereinafter GMA)
Polymer (ethylene / GMA = 85/15) with styrene copolymer grafted onto it (ethylene / GMA / styrene acrylonitrile copolymer = 70/30), manufactured by NOF Corporation A4400 B-2: a polymer in which the graft component is polystyrene in B-1; Nippon Yushi Co., Ltd. product name MODIPER 4100 B-3: an ethylene-glycidyl methacrylate copolymer;
Sumitomo Chemical Co., Ltd. Product name Bond First E 3. (c) Component C-1: Ethylene-propylene copolymer, Nippon Synthetic Rubber Co., Ltd. product name EP-02P (Mooney viscosity ML _{1 +} 424) C -2: Ethylene-propylene copolymer, manufactured by Nippon Synthetic Rubber Co., Ltd. EP-07P (Mooney viscosity ML _{1 +} 470) C-3: Styrene-butadiene-styrene block copolymer, Nippon Synthetic Rubber Co., Ltd. ) Manufactured by TR2000 C-4: hydrogenated styrene-butadiene-styrene block copolymer, manufactured by Shell Co., Ltd. Kraton G1650 Examples, Comparative Examples (a), (b), (c) ) Mix the ingredients and use a twin screw extruder to set the barrel temperature to 240
The mixture was kneaded and extruded at a temperature of 280 ° C. (280 ° C. when A-2 was used as the component (a)) and pelletized. The obtained pellets were sufficiently dried, and a test piece for evaluating impact resistance and surface appearance of a molded product was prepared using an injection molding machine, and evaluated according to the following evaluation criteria.

 Table 1 shows the evaluation results.

Evaluation Test Method Impact Resistance—Izod impact strength was measured at 23 ° C. with a notch at 1/4 ″ according to ASTM D256.

Molded product surface appearance: Obtain a molded product having a weld part,
The conspicuousness of the weld and the smoothness of the appearance were visually evaluated according to the following evaluation criteria.

◎: Very good ○: Excellent △: Somewhat poor ×: Poor workability: Using dry pellets, 260 ° C according to JISK7210 (280% when A-2 is used as component (a))
° C) and a load of 10 kg.

Impact resistance-: After a light resistance test (weather meter black panel temperature 63 ° C x 100 hours), a 3.2 mm thick plate was hit with a Dupont impact tester at the tip of a hitting rod R = 1/2 ".
Was used to measure the falling weight impact strength.

 The following can be seen from the results of the comparative examples in Table 1.

Comparative Example 1 is an example of polybutylene terephthalate alone, and has poor impact resistance.

In Comparative Example 2, the component (b) was a non-grafted product outside the present invention, and the impact resistance and the surface appearance of the molded product were poor.

Comparative Example 3 has no component (b) and has impact resistance−
,-, Surface appearance of molded product is inferior.

In Comparative Example 4, the amount of the component (c) used was small outside the range of the present invention, and the molded product surface appearance and workability were poor.

Comparative Example 5 is an example in which the use amount of the component (b) is outside the range of the present invention, and the molded product surface appearance and workability are poor.

[Effects of the Invention] The composition of the present invention is an excellent resin in which impact resistance, appearance of a molded article and moldability are highly balanced.

Accordingly, the composition of the present invention provides molded articles such as exterior and interior parts of automobiles and various electric and electronic parts and housings, which require such highly balanced physical properties. The utility value of is extremely large.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-236266 (JP, A) JP-A-64-48853 (JP, A) JP-A-63-312313 (JP, A) JP-A-1- 138261 (JP, A)

Claims (1)

(57) [Claims] 1. A graft copolymer comprising (a) 9 to 99 parts by weight of a thermoplastic polyester, and (b) a styrene-based polymer grafted on a copolymer mainly composed of an olefin unit and an epoxy group-containing unsaturated compound unit. A thermoplastic resin composition comprising: 30 parts by weight and (c) 0.95 to 90.5 parts by weight of a rubber polymer.