JPH0757837B2 - Thermoplastic polymer composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic polymer composition which is excellent in transparency, impact resistance, surface hardness, heat resistance and luster and has little warpage.

[Conventional technology]

A block copolymer composed of a conjugated diene and a vinyl aromatic hydrocarbon has excellent transparency when a relatively high vinyl aromatic hydrocarbon content is obtained, and a thermoplastic resin having better impact resistance than polystyrene can be obtained. In recent years, its usage has been increasing mainly in fields such as food packaging containers, daily sundries, toys, and light electric parts. However, such a block copolymer has a drawback that surface hardness and heat resistance are lower than those of other plastics.

On the other hand, polyphenylene ether resin is a resin excellent in dimensional stability, electrical characteristics, heat distortion resistance under high load, water resistance, etc., and is widely used industrially. Resins have the drawback of being inferior in impact resistance and molding fluidity.

For this reason, various attempts have been made to blend the block copolymer consisting of a conjugated diene and a vinyl aromatic hydrocarbon and the polyphenylene ether resin by making use of their respective advantages and complementing the drawbacks of the two. ing.

For example, in JP-A-48-62851 and JP-A-51-129450, (a) polyphenylene ether resin and (b)
A-B-A 'type elastomer block copolymers (wherein the central block B has a higher molecular weight than the combined molecular weight of the end blocks A and A') and (c)
Normally solid thermoplastic compositions consisting of styrene homopolymer or random copolymer resins are described. Further, JP-A-52-125560 discloses a thermoplastic molding composition comprising a homogeneous mixture of (i) polyphenylene ether resin, (ii) styrene resin, and (iii) radial tereblock copolymer. Have been described. Further, in JP-A-58-176240, 10 to 60 parts by weight of a vinyl aromatic compound and 40 to 90 parts by weight of a conjugated diene are used for 1 to 100 parts by weight of a modified polyphenylene oxide resin. A thermoplastic resin composition containing 20 parts by weight as a main component is described. However, the block copolymer used in these compositions is a block copolymer having a vinyl aromatic compound content of 60% by weight or less, and these compositions have transparency, surface hardness, and heat resistance. Inferior in properties and gloss.

On the other hand, Japanese Patent Publication No. 54-27025 discloses at least one monovinyl aromatic block constituting (A) 1 to 45% by weight of polyarylene oxide and (B) 10 to 90% by weight of a monovinyl aromatic block polymer. Disclosed is a thermoplastic composition containing 99 to 55% by weight of a monovinyl aromatic block polymer having a vinyl aromatic compound content of 80%.
Compositions using weight percent block copolymers are described. However, such a composition is inferior in impact resistance and has a problem that microcracks are likely to be formed when it is bent. Further, JP-A-61-223054 and JP-A-6-223054
2-70448 discloses that (a) a polyphenylene ether resin, (b) an A-B-A 'type block copolymer (wherein the molecular weight of the B block is the combination of the A and A'blocks). It is smaller than the molecular weight) and (c) an elastomer containing an impact-resistant polyphenylene ether resin composition. However, although such a composition is excellent in impact resistance, it has a problem that it is inferior in transparency and surface hardness.

Further, JP-A-50-71742, JP-A-53-94540 and JP-A-56-95949 disclose (a) polyphenylene ether resin, (b) styrene resin and (c) water. Compositions comprising additive block copolymers are described. However, the block copolymer used in such a composition has a vinyl aromatic hydrocarbon content of 60% by weight or less and is inferior in transparency, surface hardness, heat resistance and gloss.

[Problems to be solved by the invention]

The inventors of the present invention have solved the problems of the compositions proposed hitherto as described above, are excellent in transparency, impact resistance, surface hardness, heat resistance (heat distortion resistance) and gloss, and have little warpage. An intensive study was conducted in order to find a thermoplastic polymer composition.

[Means for Solving the Problems]

The present invention provides a composition comprising a block copolymer and a polyphenylene ether resin, wherein the content of vinyl aromatic hydrocarbons, the proportion of vinyl aromatic hydrocarbons present as a vinyl aromatic hydrocarbon polymer block, vinyl It was found that the above object can be achieved by using a block copolymer in which the ratio of the weight average molecular weight to the number average molecular weight of the aromatic hydrocarbon polymer block is within a specific range, respectively, and the present invention has been completed.

That is, the present invention provides (1) (a) a block copolymer comprising at least two vinyl aromatic hydrocarbon-based polymer segments and at least one conjugated diene-based polymer segment. (I) the vinyl aromatic hydrocarbon content exceeds 60% by weight,
95% by weight or less, (ii) ratio of vinyl aromatic hydrocarbons existing as a vinyl aromatic hydrocarbon polymer block in the copolymer to all vinyl aromatic hydrocarbons contained in the copolymer Is more than 75% by weight and 98% by weight or less, (iii) the ratio of the weight average molecular weight to the number average molecular weight of the vinyl aromatic hydrocarbon polymer block in the copolymer is
Block copolymer of 1.2 to 2.0 10 to 95 parts by weight (b) Thermoplastic polymer composition consisting of 5 to 90 parts by weight of polyphenylene ether (2) From (a) and (b) of the preceding item 1. 100 parts by weight of a thermoplastic polymer composition comprising (c) a polymer of vinyl aromatic hydrocarbon or a copolymer of vinyl aromatic hydrocarbon and a vinyl compound copolymerizable therewith, 3 to 400 parts by weight Composition (3) The thermoplastic polymer composition according to the above item 2, wherein the polymer of vinyl aromatic hydrocarbon is polystyrene.

Hereinafter, the present invention will be described in detail.

The block copolymer of the component (a) used in the present invention is composed of at least two vinyl aromatic hydrocarbon-based polymer segments and at least one conjugated diene-based polymer segment. Vinyl aromatic hydrocarbon content is more than 60% by weight and 95% by weight or less, preferably 65 to 90
% By weight. When the content of the vinyl aromatic hydrocarbon is 60% by weight or less, the surface hardness, heat resistance and gloss are poor, and when it exceeds 95% by weight, the impact resistance is poor, which is not preferable. In the present invention, the polymer segment mainly composed of vinyl aromatic hydrocarbon is a polymer segment containing 50% by weight or more, preferably 70% by weight or more of vinyl aromatic hydrocarbon. It is a segment composed of a copolymer block of hydrogen and a conjugated diene and a vinyl aromatic hydrocarbon homopolymer block, or a segment composed of a vinyl aromatic hydrocarbon homopolymer block.
Further, the polymer segment mainly composed of the conjugated diene, the content of the conjugated diene is more than 50 wt%, preferably a polymer segment of 70 wt% or more, the conjugated diene and vinyl aromatic hydrocarbon It is a segment composed of a copolymer block and / or a conjugated diene homopolymer block. The vinyl aromatic hydrocarbon copolymerized with the copolymer block in these segments may be distributed uniformly or in a taper shape. Further, in the copolymer block, a plurality of portions in which vinyl aromatic hydrocarbons are evenly distributed and / or portions in which the vinyl aromatic hydrocarbons are distributed in a tapered shape may coexist.

The block copolymer of the component (a) used in the present invention is contained in a copolymer of vinyl aromatic hydrocarbons existing as a vinyl aromatic hydrocarbon polymer block in the copolymer. The ratio of the total vinyl aromatic hydrocarbons (hereinafter referred to as the vinyl aromatic hydrocarbon block ratio) is
It is more than 75% by weight and 98% by weight or less, preferably 77 to 96% by weight. When the block ratio of the vinyl aromatic hydrocarbon is 75% by weight or less, surface hardness and heat resistance are poor, and when it exceeds 98% by weight, impact resistance is poor, which is not preferable. The block ratio of vinyl aromatic hydrocarbons is determined by oxidative decomposition of the copolymer with diethyl butyl hydroperoxide using osmium tetroxide as a catalyst (for example, LM
Kolthoff et al, J. Polymer Sci., 1, 429 (1946))). That is, after the block copolymer is oxidatively decomposed by the above method, a vinyl aromatic hydrocarbon polymer component obtained by adding a large amount of methanol to the decomposed product (generally a number average molecular weight of about 1,000 or more, usually about 30
The amount of block of vinyl aromatic hydrocarbon can be determined by dividing the amount of (00 to about 1,000,000) by the amount of total vinyl aromatic hydrocarbon contained in the block copolymer.

The block copolymer of the component (a) used in the present invention has a weight average molecular weight (hereinafter referred to as Mw) and a number average molecular weight (hereinafter referred to as Mn) of the vinyl aromatic hydrocarbon polymer block in the copolymer. The ratio of (referred to) as a whole is in the range of 1.2 to 2.0, preferably 1.3 to 1.8. If the Mw / Mn ratio is less than 1.2, the impact resistance is poor, and if it exceeds 2.0, molding anisotropy occurs,
This causes a problem that the molded product warps. The Mw / Mn of the vinyl aromatic hydrocarbon polymer block in the block copolymer can be measured as follows. The vinyl aromatic hydrocarbon polymer component obtained by oxidatively decomposing the block copolymer by the above-mentioned method was measured by gel permeation chromatography (GPC), and a conventional method (eg, "gel chromatography <basic edition>") was used. It can be calculated according to the method described in Kodansha issue). For the calibration curve for GPC, a standard curve that is commercially available for GPC is used.

A particularly preferred block copolymer as the block copolymer of the component (a) used in the present invention is a glass transition temperature (Tg) of a polymer segment mainly containing vinyl aromatic hydrocarbon.
Is a block copolymer having a temperature of 65 to 98 ° C, preferably 75 to 96 ° C. When a block copolymer having Tg in this range is used,
It is possible to obtain a composition with less occurrence of microcracks observed when the composition is folded. The Tg referred to here is obtained from the temperature obtained from the inflection point of the dynamic elastic modulus (E ') in the dynamic viscoelasticity measurement or from the inflection point of the temperature change in the differential scanning calorimeter (DSC). Say the temperature. Dynamic viscoelasticity is
It can be measured using a Toyo Baldwin Leo Vibron (DDV-3 type) or the like.

The block copolymer of the component (a) used in the present invention has a polymer structure represented by the general formula: (AB) _{n + 1} , AB-A) _n , BA-B) _n (wherein A is vinyl. It is a polymer block mainly composed of aromatic hydrocarbons and B is a polymer block mainly composed of conjugated dienes, and the boundary between the A block and the B block does not necessarily have to be clearly distinguished. Is an integer of 1 or more, preferably an integer of 1 to 5.) Or general formula (In the above formula, A and B are the same as above, and X is the residue of the coupling agent such as silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, polyhalogenated hydrocarbon, carboxylic acid ester, polyvinyl compound, etc. Group or a residue of an initiator such as a polyfunctional organolithium compound, m and n are integers of 1 or more, preferably m is an integer of 1 to 10 and n is an integer of 1 to 5). Block copolymers can be used. The block copolymer used in the present invention may be any mixture of the block copolymers represented by the above general formula.

Examples of the vinyl aromatic hydrocarbon used in the method of the present invention are styrene, o-methylstyrene, p-methylstyrene, p
-Tert-butylstyrene, 1,3-dimethylstyrene, α
-Methyl styrene, vinyl naphthalene, vinyl anthracene, etc., but styrene is particularly common. These may be used alone or in combination of two or more.

The conjugated diene used in the present invention is diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene) and 2,3-dimethyl-1. 1,3-Butadiene, 1,3-pentadiene, 1,3-hexadiene and the like, and particularly common ones include 1,3-butadiene and isoprene. These may be used alone or in combination of two or more.

The block copolymer used in the present invention is a hydrocarbon solvent,
It is obtained by polymerizing an organolithium compound as an initiator.

Hydrocarbon solvents include butane, pentane, hexane, isopentane, heptane, octane, isooctane and other aliphatic hydrocarbons; cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane and other alicyclic hydrocarbons; or benzene, Aromatic hydrocarbons such as toluene, ethylbenzene and xylene can be used. Organolithium compounds have 1 in the molecule
An organolithium compound having at least one lithium atom bonded thereto, such as ethyllithium, n-propyllithium,
Examples thereof include isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, hexamethylene dilithium, butadienyl dilithium and isoprenyl dilithium.

In the block copolymer of the component (a) used in the present invention, the number average molecular weight of the segment A is 5,000 to 500,000, preferably 70,000 to 300,000, and the number average molecular weight of the segment B is 1,000 to 400,000, preferably 3,000 to 300,000
Is. The number average molecular weight of the block copolymer as a whole is 10,000 to 1,000,000, preferably 30,000 to 500,000.

As the block copolymer used in the present invention, a block copolymer in which a polar group-containing atomic group is bonded to at least one polymer chain end of the polymer can be used. Here, the polar group-containing atomic group is nitrogen, oxygen, silicon, phosphorus, sulfur,
It means an atomic group containing at least one atom selected from tin. Specifically, a carboxyl group, a carbonyl group,
Thiocarbonyl group, acid halide group, acid anhydride group, carboxylic acid group, thiocarboxylic acid group, aldehyde group, thioaldehyde group, carboxylic acid ester group, amide group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, Phosphate ester group, amino group, imino group, nitrile group, viridyl group, quinoline group, epoxy group, thioepoxy group, sulfido group, isocyanate group, isothioneanate group, silicon halide group, alkoxy silicon group, tin halide group And an atomic group containing at least one polar group selected from an alkyltin group, a phenyltin group and the like.
More specifically, the terminal-modified block copolymer described in Japanese Patent Application No. 60-224806 can be used.

In the present invention, the hydrogenated product of the above block copolymer or terminal modified block copolymer can be used. The catalyst used in the hydrogenation reaction is (1) Ni, Pt,
Carbon, silica, alumina, a supported heterogeneous catalyst in which a metal such as Ru is supported on a carrier such as diatomaceous earth,
(2) So-called Ziegler type catalysts using organic acid salts such as Ni, Co, Fe, Cr or acetylaton salts and reducing agents such as organic Al, or so-called organic complex catalysts such as organic metal compounds such as Ru and Rh. Of homogeneous catalysts are known. As a specific method, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636,
Alternatively, according to the methods described in JP-A-59-133203 and JP-A-60-220147, hydrogenation is carried out in the presence of a hydrogenation catalyst in an inert solvent to obtain a hydrogenated product. It is possible to synthesize the hydrogenated polymer to be used in the above. At that time, the hydrogenation rate of the aliphatic double bond based on the conjugated diene compound in the polymer can be controlled to an arbitrary value by adjusting the reaction temperature, the reaction time, the hydrogen supply amount, the catalyst amount and the like. For example, when improving the heat deterioration resistance and the like while maintaining the properties of the unhydrogenated polymer, the aliphatic double bond based on the conjugated diene is 3% or more and less than 80%, preferably 5% or more and less than 75%. Is hydrogenated by 10 to 45%, or 80% or more, preferably 90% to improve heat deterioration resistance and weather resistance.
The above hydrogenation is recommended. In this case, hydrogen of an aromatic double bond based on the vinyl aromatic compound copolymerized with the polymer block A mainly containing the vinyl aromatic compound and the polymer block B mainly containing the conjugated diene compound as the case requires. The addition rate is not particularly limited, but the hydrogen addition rate is preferably 20% or less. The amount of unhydrogenated aliphatic double bonds contained in the hydrogenated block copolymer can be easily known by an infrared spectrometer, a nuclear magnetic resonance apparatus or the like.

Next, the polyphenylene ether of the component (b) used in the present invention has the general formula: (At least one of R ₁ and R _{2 in} the formula is a linear or primary or secondary branched alkyl group having 1 to 4 carbon atoms,
Aryl group, the rest of the halogen atoms are hydrogen atoms, which may be the same or different from each other), a homopolymer comprising a repeating unit represented by the general formula (I). Repeating unit and general formula (In the formula, R ₃ , R ₄ , R ₅ and R ₆ are each a linear or primary or secondary branched chain alkyl group having 1 to 4 carbon atoms, an aryl group, a halogen atom, hydrogen Atoms, etc., which may be the same or different from each other, but R ₃ and R ₄ cannot be hydrogen atoms at the same time) Coalescence, a graft copolymer obtained by graft-polymerizing styrene to these homopolymers or copolymers, and the like.

Typical examples of polyphenylene ether homopolymers include 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-chloro-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl-1) Homopolymers such as 4,4-phenylene) ether may be mentioned.

The polyphenylene ether copolymer is an o-cresol or a general formula. (Wherein R ₃ , R ₄ , R ₅ and R ₆ have the same meanings as described above), a polyphenylene ether obtained by copolymerization with an alkyl-substituted phenol such as 2,3,6-trimethylphenol It includes a polyphenylene ether copolymer mainly composed of a structure.

The number average degree of polymerization (n) of polyphenylene ether is 50 to
It is selected from the range of 500, preferably 75 to 250. When the number average degree of polymerization is less than 50, physical properties such as impact strength of the obtained composition are remarkably deteriorated and it is difficult to put to practical use. If it exceeds 500,
Processing fluidity of the obtained composition becomes poor, and gelation tends to occur, which is not preferable.

As the polyphenylene ether used in the present invention, a modified polyphenylene ether obtained by adding and / or graft-polymerizing a radically polymerizable vinyl compound to the above homopolymer or copolymer can be used. As the vinyl compound, the vinyl aromatic hydrocarbons and halogen-substituted products thereof, unsaturated monocarboxylic acid esters such as acrylic acid ester and methacrylic acid ester, unsaturated carboxylic acid amides such as acrylic acid amide and methacrylic acid amide, Examples thereof include unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, acid anhydrides of these unsaturated dicarboxylic acids, esters, amides, imides, nitrile monomers such as acrylonitrile and methacrylonitrile.

In the present invention, a polymer of the above vinyl aromatic hydrocarbon or a copolymer of the above vinyl aromatic hydrocarbon and a vinyl compound copolymerizable therewith (hereinafter referred to as component (C)).
And) can be used. The above-mentioned vinyl compound can be used as the copolymerizable monomer. Preferred (co) polymers as component (C) are polystyrene,
Styrene-α-methylstyrene copolymers, acrylonitrile-styrene copolymers, styrene-methacrylic acid ester copolymers, styrene-maleic anhydride copolymers, and the like, and these are used alone or as a mixture of two or more kinds. can do. These (co) polymers are effective in further improving the surface hardness and rigidity of the composition. Especially, the component (C) is preferably polystyrene.

Further, in the present invention, a rubber-modified vinyl aromatic hydrocarbon polymer (hereinafter referred to as component (D)) can be blended. The rubber-modified vinyl aromatic hydrocarbon polymer is obtained by polymerizing a mixture of the vinyl aromatic hydrocarbon or a monomer copolymerizable therewith with an elastomer, and as a polymerization method, suspension polymerization, emulsion polymerization, Bulk polymerization, bulk-suspension polymerization, etc. are generally performed. Examples of monomers copolymerizable with vinyl aromatic hydrocarbons include α
-Methylstyrene, acrylonitrile, acrylic acid ester, methacrylic acid ester, maleic anhydride, and the like vinyl compounds described above. As the elastomer, natural rubber, synthetic isoprene rubber, butadiene rubber,
Styrene-butadiene rubber, high styrene rubber, polybutadiene rubber, chloroprene rubber, polybutene rubber, rubber-like ethylene-propylene copolymer, rubber-like butadiene-acrylonitrile copolymer, butyl rubber, various nitrile rubbers, rubber-like ethylene-vinyl acetate copolymer Polymers, rubber-like ethylene-acrylic acid ester copolymers, rubber-like atactic polypropylene resins, rubber-like ethylene-acrylic acid ionomers and the like are used.

These elastomers are generally 2 to 70 parts by weight, more usually 3 to 50 parts by weight based on 100 parts by weight of vinyl aromatic hydrocarbon or a monomer copolymerizable therewith, or dissolved in the monomer or in a latex form. For bulk polymerization, bulk-suspension polymerization, emulsion polymerization and the like.

Particularly preferred rubber-modified polymers include impact-resistant rubber-modified styrene polymers, acrylonitrile-butadiene-styrene copolymers, acrylic acid ester-butadiene-styrene copolymers, methacrylic acid ester-butadiene-polymers.
Examples thereof include styrene copolymers and impact-resistant rubber-modified styrene-maleic anhydride copolymers, which may be used alone or as a mixture of two or more kinds.

In the present invention, the blending weight ratio of the component (a) and the component (b) is such that the component (a) is 10 to 95% by weight, preferably 20 to 85% by weight, more preferably 30 to 80% by weight. Component (a)
If it is less than 10% by weight, impact resistance and workability are poor, and if it exceeds 95% by weight, heat resistance and surface hardness are poor, which is not preferable. A particularly preferred blending weight ratio is 35% for component (a).
% To 75% by weight, and in this range, a composition having an impact strength superior to the impact strength of each of the component (a) and the component (b) alone can be obtained. It

In the present invention, 500 parts by weight or less, preferably 3 parts by weight, relative to 100 parts by weight of the composition comprising the components (a) and (b).
The above component (C) can be added in an amount of ˜400 parts by weight, more preferably 5 to 300 parts by weight. The processability can be improved by using the component (C). If the compounding amount of the component (C) exceeds 500 parts by weight, impact resistance and heat resistance decrease, which is not preferable.

Further, in the present invention, the amount is 500 parts by weight or less, preferably 3 to 400 parts by weight, more preferably 5 to 300 parts by weight with respect to 100 parts by weight of the composition comprising the components (a) and (b). The impact resistance can be improved by blending the component (D). If the compounding amount of the component (D) exceeds 500 parts by weight, the heat resistance is lowered, which is not preferable. In order to obtain a composition having good transparency, it is recommended that the amount of the component (D) be 50 parts by weight or less, preferably 25 parts by weight or less.

The thermoplastic polymer composition of the present invention may be blended with other thermoplastic resins and rubber-like polymers. As the thermoplastic resin, polyethylene, a copolymer of ethylene containing 50% or more of ethylene and another monomer copolymerizable therewith, polypropylene, propylene containing 50% or more of propylene and a monomer copolymerizable therewith Copolymer with,
Polybutene-based resin, polyvinyl chloride-based resin, polyvinyl acetate-based resin and its hydrolyzate, polyacrylate-based resin, acrylonitrile-based resin, polyamide-based resin, polyester-based resin, polyphenylene sulfide-based resin, polyacetal-based resin, Examples thereof include polycarbonate resin, polysulfone resin, thermoplastic polyurethane resin, polybutadiene resin, polyacrylate resin, fluorine resin, polyoxybenzoyl resin, and polyimide resin. Further, as the rubber-like polymer, polybutadiene, polyisoprene, styrene-butadiene copolymer, butadiene-acrylonitrile copolymer, ethylene-propylene copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer , Silicone rubber, epichlorohydrin rubber, acrylic rubber, ethylene-vinyl acetate copolymer and the like.

The thermoplastic polymer composition of the present invention can contain any additive, if necessary. The kind of the additive is not particularly limited as long as it is one generally used for compounding plastics, for example, glass fiber, glass beads, silica,
Inorganic reinforcing agents such as charcoal and talc, organic fibers, organic reinforcing agents such as coumarone indene resin, organic peroxides,
Inorganic peroxide and other crosslinking agents, titanium white, carbon black, iron oxide and other pigments, dyes, flame retardants, antioxidants, UV absorbers, antistatic agents, lubricants, plasticizers, other extenders or mixtures thereof. And so on.

The thermoplastic polymer composition of the present invention can be produced by any conventionally known compounding method. For example, an open roll, an intensive mixer, an internal mixer, a co-kneader, a continuous kneader with a twin-screw rotor, a melt-kneading method using a general kneader such as an extruder, each component is dissolved or dispersed in a solvent and then mixed with a solvent. And the like are used.

〔Example〕

Examples will be shown below, but these are representative of the present invention and do not limit the scope of the present invention.

Example 1 and Comparative Examples 1 to 7 A styrene / butadiene block copolymer having a polymer structure represented by the general formula A ₁ -BA ₂ was produced in cyclohexane using n-butyllithium as a catalyst. In the production of the block copolymer, Mw / Mn is adjusted by changing the ratio of the amount of styrene used for A ₁ part and the amount of styrene used for A ₂ part. It was adjusted by continuously supplying a mixed monomer of styrene and butadiene to the polymerization vessel and changing the ratio thereof. The melt flow index (MI (G)) is n
-Adjusted by changing the amount of butyllithium. The obtained block copolymer was pelletized by an extruder, and then melt-kneaded with polyphenylene ether and polystyrene by a twin-screw extruder. After that, a flat plate having a thickness of 3 mm was injection-molded at 250 ° C. using IS-80A (50 g injection molding machine) manufactured by Toshiba Machine Co., Ltd.

The physical properties of the obtained injection-molded product are shown in Table 1. The block copolymer composition within the scope of the present invention has transparency, impact resistance,
The molded product was excellent in heat resistance and surface hardness, and also had good microcrack resistance, and was less warped.

(Note 1) Polyphenylene ether resin with an intrinsic viscosity of 0.57dl / g (25 ℃, chloroform) is used.

(Note 2) Styron 685 manufactured by Asahi Kasei Corporation is used.

(Note 3) Compliant with ASTM D-1709 (Note 4) Compliant with JIS K-5400 (Note 5) Compliant with JIS K-6714 (Note 6) Compliant with JIS K-6871 (Note 7) Compliant with ASTM D-790 Based on the bending test method described above, the occurrence of microcracks observed when the test piece was bent and deformed was observed, and the microcrack property was evaluated by the amount of deformation of the center part of the test piece at the time of microcrack generation.

⊚: The amount of deformation when microcracks occur exceeds 10 mm.

◯: Microcracks are generated in a range where the amount of deformation exceeds 3 mm and 10 mm or less.

X: A microcrack occurs when the deformation amount is 3 mm or less.

(Note 8) The warpage of the injection-molded product is closely related to the difference in the molding shrinkage ratio between the flow direction of the molded product and the direction perpendicular to it.
The larger the difference is, the larger the warp of the injection-molded article is.

Ranking was performed as follows according to the difference in molding shrinkage.

0.2% or less ◎ Exceeding 0.2% and 0.4% or less ○ Exceeding 0.4% and 0.6% or less △ Exceeding 0.6% × In addition, the molding shrinkage in the direction perpendicular to the flow direction is the molding shrinkage on the side opposite to the gate side did.

Examples 2, 3, 4 and Comparative Examples 8, 9 By the same method as in Example 1, the polymer structure has the general formula A _1-
A styrene / butadiene block copolymer represented by BA ₂ was produced. Mixing with polyphenylene ether and polystyrene and molding were performed in the same manner as in Example 1. The physical properties of the obtained injection-molded products are shown in Table 2. The block copolymer composition within the scope of the present invention was excellent in impact resistance, pencil hardness, and heat resistance, and was excellent in gloss without warping of a molded product.

(Note 9) A dumbbell test piece according to ASTM D638 was used, and a dead end portion was measured at an incident angle of 60 ° using a gloss meter manufactured by Suga Test Instruments.

Evaluation rank ○: 95% or more △: 85% or more, less than 95% ×: less than 85% Examples 5 to 9 The polymer structure is represented by the general formula B ₁ -A ₁ -B ₂ -A ₂ , A ₁ -B ₁ -A. ₂ -B ₂
-A ₃ and (A ₁ -B _{1 4} X (X represents a residue of SiCl ₄ ).
A block copolymer represented by: was produced in the same manner as in Example 1. Mixing with polyphenylene ether and polystyrene and molding were performed in the same manner as in Example 1. Table 3 shows the physical properties of the obtained injection-molded products.

Example 10 100 parts by weight of the block copolymer composition of Example 1 was melt-kneaded with 3 parts by weight of antimony trioxide, 30 parts by weight of decabromotetralin and 35 parts by weight of glass fiber to prepare a test piece for measuring physical properties. As a result of preparation and measurement of physical properties, high impact resistance, high heat resistance and scratch resistance were good, and further, excellent physical properties having flame retardancy were shown.

Example 11 A styrene / butadiene block copolymer having a polymer structure represented by the general formula A ₁ -BA ₂ was produced in cyclohexane using n-butyllithium as a catalyst. Then, this block copolymer was hydrogenated with a Ti-based hydrogenation catalyst described in JP-A-59-133203, and a hydrogenated block copolymer in which about 99% of the aliphatic double bonds in the butadiene portion were hydrogenated. Was produced.

Next, the obtained hydrogenated block copolymer was melt-kneaded with polyphenylene ether and polystyrene with a twin-screw extruder.
The physical properties of the obtained composition are shown in Table 4.

Example 12 In the composition of Example 1, instead of polystyrene,
Styrene / methyl methacrylate copolymer, impact resistant rubber modified styrene polymer (HIPS), acrylonitrile / butadiene / styrene copolymer (ABS), methyl methacrylate / butadiene / styrene copolymer (MBS) were used respectively. A composition was made. The obtained compositions were all excellent in impact resistance, surface hardness and heat resistance.

Examples 13 to 17 and Comparative Examples 10 to 11 Polymer compositions were prepared and injection molded in the same manner as in Example 1 except that the polystyrene used as the component (C) in Example 1 was excluded from the composition. Then, the physical properties were evaluated. The evaluation results obtained are shown in Table 5.

The composition of the present invention was excellent in transparency, impact resistance, heat resistance and surface hardness even in the two-component system of (a) block copolymer and (b) polyphenylene ether.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The thermoplastic polymer composition of the present invention can be utilized for various purposes by utilizing its excellent transparency, impact resistance, surface hardness, heat resistance and luster. The composition of the present invention may be extrusion molded, injection molded,
It can be molded into sheets, films, foams, injection molded products of various shapes, hollow molded products, compressed air molded products, vacuum molded products, etc. by blow molding, food packaging containers, household appliances, automobile parts, industrial products, toys, etc. Can be used for. In particular,
Since the composition of the present invention has little warpage when injection-molded, it is suitable for injection molding of flat-plate shaped articles, molded articles having many flat-plate portions, and large-sized molded articles.

Claims (3)

[Claims] 1. A block copolymer comprising (a) a polymer segment mainly containing at least two vinyl aromatic hydrocarbons and at least one polymer segment mainly containing a conjugated diene, wherein (i) Vinyl aromatic hydrocarbon content exceeds 60% by weight,
95% by weight or less, (ii) ratio of vinyl aromatic hydrocarbons existing as a vinyl aromatic hydrocarbon polymer block in the copolymer to all vinyl aromatic hydrocarbons contained in the copolymer Is more than 75% by weight and 98% by weight or less, (iii) the ratio of the weight average molecular weight to the number average molecular weight of the vinyl aromatic hydrocarbon polymer block in the copolymer is
A thermoplastic polymer composition comprising 10 to 95 parts by weight of a block copolymer of 1.2 to 2.0 (b) 5 to 90 parts by weight of polyphenylene ether. 2. The thermoplastic polymer composition according to claim 1, 100 parts by weight (c) A polymer of vinyl aromatic hydrocarbon or a copolymer of vinyl aromatic hydrocarbon and a vinyl compound copolymerizable therewith. 3 to 400 parts by weight 3. The thermoplastic polymer composition according to claim 2, wherein the polymer of vinyl aromatic hydrocarbon is polystyrene.