JPH0546383B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a thermoplastic resin composition having excellent impact resistance, and more particularly, the present invention relates to a thermoplastic resin composition having excellent impact resistance, and more particularly, the monomer component is a block copolymer consisting of a vinyl aromatic hydrocarbon and a conjugated diene, and A resin composition consisting of a polyphenylene ether resin mixed with a block copolymer in which all ends of the molecular chain are composed of elastomeric blocks and the composition ratio of elastomeric blocks and non-elastomeric blocks is specified. relating to things. [Prior Art] Conventionally, polyphenylene ether resins or resin compositions blended with thermoplastic resins such as rubber-modified impact-resistant aromatic monovinyl resins have poor moldability,
As a resin with a good balance of processability, heat resistance, impact resistance, flame retardance, and electrical properties, it can be used for example in industrial parts, electrical parts, office equipment housings, automobile parts, etc.
It is widely used in precision parts, etc., especially in recent years.
As mentioned above, since it has a good balance of physical properties, its usage is increasing significantly. With such an increase in the amount used, the quality of the resin composition is also required to be increasingly high, and there is a strong desire to improve the resin properties. For example, in industrial parts and electrical parts, there is a growing tendency to use injection molding methods using pin gates and hot runners in order to improve the design of molded products or save labor. Improvements are requested. In response to such demands, attempts have already been made to improve impact resistance by blending a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene with a polyphenylene ether resin. For example, JP-A-48
JP-A-62851, JP-A-51-129450, and JP-A-52-125560 disclose compositions in which linear block copolymers and radial block copolymers are blended with polyphenylene ether resins. Are listed. That is, JP-A-48-62851 and JP-A-51-
Publication No. 129450 describes (a) a polyphenylene ether resin, (b) an A-B-A' type elastomer block copolymer of vinyl aromatic compounds A and A' and conjugated diene B, and (c) an optional component. Thermoplastic resin compositions are described which consist of styrene homopolymer or random copolymer resins as described above. Also, JP-A-52-
Publication No. 125560 discloses a thermal polymer comprising a homogeneous mixture of (i) a polyphenylene ether resin, (ii) a styrene resin, and (iii) a radial teleblock copolymer consisting of a vinyl aromatic compound, a conjugated diene, and a coupling agent. Plastic molding compositions are described. This radial teleblock copolymer is a radial teleblock copolymer of styrene and butadiene having terminal blocks derived from styrene, and also in the above publication, the terminal blocks are polymers derived from styrene. However, although the resin compositions described in these documents can be expected to have a certain degree of impact resistance improvement effect, they are still insufficient depending on the application, and in order to achieve a high degree of impact resistance, these resin compositions cannot be used. It is necessary to increase the blending amount of the block copolymer described above, and in such a case, problems such as a decrease in rigidity and heat resistance arise. [Problems to be Solved by the Invention] The present invention has been made in order to improve the impact resistance of polyphenylene ether resins, which has been a problem in the past as described above. [Means and effects for solving the problems] The present invention is a block copolymer whose monomer components are a vinyl aromatic hydrocarbon and a conjugated diene, and in which all the ends of the polymer molecular chain are composed of elastomeric blocks. Furthermore, we have discovered that when a block copolymer with a specified composition ratio of elastomeric blocks and non-elastomeric blocks is blended into polyphenylene ether resin, impact resistance is greatly improved. It was based on That is, the present invention provides (1)(A) polyphenylene ether resin
60 to 99 parts by weight (B) The following general formula (a) B ₁ −A ₁ −B ₂ (-A-B) _o --A ₂ −B ₃ (b) [B ₁ −A ₁ −B ₂ ( -A-B) _o --] _n+2 ---
X (c) [B ₁ −A ₁ −B ₂ (-A-B) _o --A] _n+2 --
-X (In the above formula, B, B ₁ , B ₂ , B ₃ are elastomeric blocks, A, A ₁ , A ₂ are non-elastomeric blocks, X is silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, Indicates the residue of a coupling agent such as a polycarboxylic acid ester or the residue of an initiator such as a polyfunctional organolithium compound. m and n are 0 or an integer of 1 to 5. A non-elastomeric block is composed of a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene and/or a conjugated diene homopolymer with an aromatic hydrocarbon content of 50% by weight or less. It is composed of a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene or/and a vinyl aromatic hydrocarbon homopolymer in an amount exceeding 75% by weight.In addition, A, A ₁ ,
A ₂ or B, B ₁ , B ₂ , and B ₃ may have the same or different molecular weights, compositions, and microstructures. ) consisting of at least three elastomeric blocks and at least two non-elastomeric blocks, the weight ratio of vinyl aromatic hydrocarbon to conjugated diene is from 10:90 to 55:45, and the number average molecular weight is is 10,000 to 1,000,000, (i) all ends of the polymer molecular chain are elastomeric blocks (hereinafter referred to as molecular chain-terminated elastomeric blocks), and (ii) polymer (iii) the content of elastomeric blocks at molecular chain ends in the polymer molecular chain is 25% by weight or more, iv) A block copolymer in which the content of the elastomeric block at each end of the molecular chain in the total amount of the elastomeric block at the end of the molecular chain and the non-elastomeric block adjacent to the block is 10% by weight or more at each end 1 to 40% by weight The present invention relates to a thermoplastic resin composition having excellent impact resistance, in which the total amount of components (A) and (B) is 100 parts by weight. Since the resin composition of the present invention has excellent impact resistance,
It has improved cracking during demolding and can be used for industrial parts, electrical parts, automobile internal parts, etc. Also,
The resin composition of the present invention has good colorability and gloss, and is suitable as a material for office equipment housings. Furthermore, the resin composition of the present invention has good stress cracking properties, and by taking advantage of this property, it can also be used as a material for parts inside vending machines that have more complex shapes and have many screwed, caulked, ringed parts, and metal insert parts. Available. The present invention will be explained in detail below. The polyphenylene ether resin used in the present invention is a polyphenylene ether resin or a mixture of a polyphenylene ether resin and another thermoplastic resin. In the present invention, the polyphenylene ether resin (PPE) has the general formula;

【formula】

[Formula] (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ are the same or different alkyl groups having 1 to 4 carbon atoms excluding tert-butyl groups, aryl groups, halogens, hydrogen, etc. is a monovalent residue, and R ₅ and R ₆ are not hydrogen at the same time) as a repeating unit, and the structural unit [] or []
A homopolymer or copolymer consisting of and [ ] can be used. Typical examples of homopolymers of PPE include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl 1,4-phenylene) ether, and poly(2,6-dimethyl-1,4-phenylene) ether. 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-methyl-6-isopropyl-1,4-phenylene) ether, poly(2-methyl-6-chloro-1,4-phenylene) ether, poly(2-
Examples include homopolymers such as methyl-6-hydroxyethyl-1,4-phenylene) ether and poly(2-methyl-6-chloroethyl-1,4-phenylene) ether. Polyphenylene ether copolymer has the general formula (Here, R ₃ , R ₄ , R ₅ , and R ₆ have the same meanings as above.) Copolymerization of an alkyl-substituted phenol such as 2,3,6-trimethylphenol with, for example, o-cresol, etc. It includes a polyphenylene ether copolymer mainly composed of a polyphenylene ether structure obtained by Furthermore, these polymers may be grafted with a monomer containing styrene as a main component. Other thermoplastic resins used in combination with the polyphenylene ether resin in the present invention include styrenic resins, rubber-modified high-impact styrene resins, polyethylene resins, polypropylene resins, polybutene resins, and polyvinyl chloride resins. resin,
Selected from polyvinyl acetate resin, polyamide resin, thermoplastic polyester resin, polyacrylate resin, polyphenylene sulfide resin, polycarbonate resin, polyacetal resin, thermoplastic polyurethane resin, polysulfone resin, etc. At least one type of thermoplastic resin. The blending ratio of these thermoplastic resins and polyphenylene ether resins is generally in the range of 1:99 to 90:10 (weight ratio). Preferably from 3:97
The ratio is 80:20, more preferably 5:95 to 70:30. Among these thermoplastic resins, styrene resins have the general formula

[During the ceremony R: hydrogen, lower alkyl group or halogen Z: a group selected from the group consisting of vinyl group, hydrogen, halogen and lower alkyl group p: an integer from 1 to 5]

One or two aromatic vinyl monomers represented by
It is a polymer consisting of styrene, α-methylstyrene, vinyltoluene, vinylethylbenzene, vinylxylene, tert-butylstyrene, chlorostyrene, etc.
Or a copolymer with a vinyl compound copolymerizable with these aromatic vinyl compounds, such as acrylonitrile, methyl methacrylate, methacrylonitrile, maleic anhydride, or a copolymer with a styrene content.
Contains 60% by weight or more of styrene-butadiene block copolymer resin. In addition, what is rubber-modified impact-resistant styrenic resin?
Butadiene rubbers such as polybutadiene, butadiene-styrene copolymers, butadiene-styrene block copolymers different from component (B), butadiene-acrylonitrile copolymers, acrylate ester rubbers, ethylene-propylene rubbers, butyl rubbers, chloroprene rubbers, and It is a styrenic resin containing one or more rubber phases such as natural rubber, and the resin phase components include polymers derived from the above-mentioned aromatic vinyl monomers and/or these aromatic vinyl compounds. Also included are copolymers of vinyl compounds copolymerizable with Styrenic resins and rubber-modified impact-resistant styrenic resins can be produced by any method well known in the art, such as solution polymerization, bulk polymerization, bulk suspension polymerization, suspension polymerization, or emulsion polymerization. It can be anything. Next, the block copolymer used in the present invention is
The following general formula, (a) B ₁ -A ₁ -B ₂ (-A-B) _o - A ₂ -B ₃ (b) [B ₁ -A ₁ -B ₂ (-A-B) _o - --] _n+2 ---X (c) [B ₁ −A ₁ −B ₂ (-A-B) _o --A] _n+2 ---X (In the above formula, B, B ₁ , ₂ and _B3 are elastomeric blocks, A, _A1 , and _A2 are non-elastomeric blocks, and X is a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, or polycarboxylic acid ester Indicates the residue of an initiator such as a functional organolithium compound. m and n are 0 or an integer of 1 to 5. Elastomeric block is a vinyl block having a vinyl aromatic hydrocarbon content of 50% by weight or less. The non-elastomeric block is composed of a copolymer of an aromatic hydrocarbon and a conjugated diene or/and a conjugated diene homopolymer, and the non-elastomeric block is composed of a vinyl aromatic hydrocarbon with a vinyl aromatic hydrocarbon content of more than 75% by weight. Copolymer with conjugated diene or/
and a vinyl aromatic hydrocarbon homopolymer. In addition, A, A ₁ , A ₂ or B,
B ₁ , B ₂ , and B ₃ may have the same or different molecular weights, compositions, and microstructures. ) consisting of at least three elastomeric blocks and at least two non-elastomeric blocks, the weight ratio of vinyl aromatic hydrocarbon to conjugated diene being 10:90 to 55:45, preferably
In a block copolymer with a ratio of 15:85 to 50:50, (i) the ends of the polymer molecular chains are all composed of elastomeric blocks at the end of the molecular chain, and (ii) the ends of the elastomeric blocks at the end of the molecular chain in the polymer molecular chain are The content is 6 to 70% by weight, preferably 10 to 60% by weight (iii) The content of elastomeric blocks in the polymer molecular chain other than the molecular chain terminal elastomeric blocks is 25% by weight or more, preferably 30 to 75% by weight. (iv) The content of the molecular chain-terminated elastomeric block in the total amount of the molecular chain-terminated elastomeric block and the non-elastomeric block adjacent to the molecular chain-terminated block is 10% by weight or more, preferably 20 to 75% by weight.
% by weight of a block copolymer. If the above constituent requirements such as the weight ratio of vinyl aromatic hydrocarbon and conjugated diene in the block copolymer, the presence or absence of molecular chain terminal elastomeric blocks, the content of molecular chain terminal elastomeric blocks, etc., deviate from the above ranges, the resin will deteriorate. When made into a composition, the effect of improving impact resistance is poor, which is not preferable. In the present invention, an elastomeric block is composed of a copolymer of vinyl aromatic hydrocarbon and conjugated biene and/or a conjugated diene homopolymer with a vinyl aromatic hydrocarbon content of 50% by weight or less, and is a non-elastomeric block. The term block refers to a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene or/and a vinyl aromatic hydrocarbon homopolymer having a vinyl aromatic hydrocarbon content of more than 75% by weight, preferably 85% by weight or more. It consists of: The vinyl aromatic hydrocarbon and the conjugated diene in the copolymer may be uniformly distributed in the copolymer or may be distributed in a tapered manner. The number average molecular weight of the block copolymer used in the present invention is 10,000 to 1,000,000, preferably 20,000 to 1,000,000.
500000. The polymer structure of the block copolymer used in the present invention can be exemplified by the following general formula. (B) B ₁ −A ₁ −B ₂ (-A-B) _o --A ₂ −B ₃ (B) [B ₁ −A ₁ −B ₂ (-A-B) _o --] _n+2 ---X (c) [B ₁ -A ₁ -B ₂ (-A-B) _o --A] _n+2 ---X (In the above formula, B, B ₁ , B ₂ , B ₃ are Elastomeric block; A, A ₁ and A ₂ are non-elastomeric blocks; (m and n are integers of 0 or 1 to 5.) To specifically explain the above constituent requirements based on the above general formula, the molecular chain terminal elastomer property in the polymer molecular chain In the case of (a), the content of the block means the content of B ₁ + B ₃ in the entire polymer;
In the case of (b) and (c), B ₁ × in the entire polymer
(m+2), and the content of elastomeric blocks in the polymer molecular chain other than the molecular chain terminal elastomeric blocks is:
In case (a), A ₁ -B ₂ (-A-B) _{o --} content of B ₂ +B x n in A ₂ ; in case (b), [A ₁ -B ₂ (-A- _B ) The content of [B ₂ +B x n] x (m-2) in o] _n+2 , in the case of (c), [A ₁ -B ₂ (-A-B) _o --A] _{n +2} means the content of [B ₂ +B×n]×(m+2),
In the case of (a), the content of the elastomeric block at the molecular chain end in the total amount of the elastomeric block at the molecular chain end and the non-elastomeric block adjacent to the block is the content of B ₁ subtracted from B ₁ + A ₁ . In the case of ( _b ) and (c ₎ , it means the content of _{B 1} in B ₁ +A ₁ . In addition, in the above general formula, A, A ₁ , A ₂ or B,
B ₁ , B ₂ , and B ₃ may have the same or different molecular weights, compositions, and microstructures. The above block copolymer is prepared in a hydrocarbon solvent.
It can be produced by sequentially polymerizing a monomer for forming an elastomeric block and a monomer for forming a non-elastomeric block using an organic lithium compound or the like as a catalyst. Vinyl aromatic hydrocarbons used in the production of the block copolymer used in the present invention include styrene, o-methylstyrene, p-methylstyrene,
Among them, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, etc., and styrene is particularly common. These may be used not only as a single type but also as a mixture of two or more types. Also,
The conjugated diene is a diolefin having a pair of conjugated double bonds having 4 to 8 carbon atoms, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1, ，
3-butadiene, 1,3-pentadiene, 1,3
-hexadiene, etc., and particularly common ones include 1,3-butadiene and isoprene. These may be used not only alone, but also as a mixture of two or more. The block copolymer used in the present invention is blended into the thermoplastic resin after being subjected to modification treatments such as hydrogenation, halogenation, sulfonation, hydroxylation, epoxidation, and maleation, if necessary. It is also possible. In the present invention, the blending weight ratio of the polyphenylene ether resin as component (A) and the block copolymer as component (B) is 60:40 to 99:1, preferably 70:30 to
The ratio is 98:2, more preferably 70:30 to 97:3.
If the amount of component (B) is less than 1% by weight, the effect of improving impact resistance will not be sufficient, and if it exceeds 40% by weight, the rigidity and heat resistance of the thermoplastic resin component will decrease, so it is preferable. do not have. The thermoplastic resin composition of the present invention may optionally contain a conjugated diolefin polymer as component (B).
It may be blended in an amount of 50 parts by weight or less, preferably 30 parts by weight or less, per 100 parts by weight of the block copolymer. If the amount of the conjugated diolefin polymer exceeds the above range, the impact resistance of the composition will deteriorate, which is not preferable. As the conjugated diolefin polymer, natural rubber, total polyisoprene, polybutadiene, butadiene-styrene copolymer rubber, isoprene-styrene copolymer rubber, etc. are used.
In addition, if desired, other additives such as plasticizers, stabilizers, ultraviolet absorbers, flame retardants, colorants,
Also, fibrous reinforcing agents such as glass fibers and carbon fibers, and fillers such as glass beads, calcium carbonate, and talc may be added. As a plasticizer,
Polybutene, low molecular weight polyethylene, mineral oil, epoxidized soybean oil, polyethylene glycol, fatty acid esters are particularly good, and flame retardants include aromatic phosphate esters, red phosphorus, aromatic halogen compounds, antimony trioxide, etc. Particularly effective. In the present invention, the thermoplastic resin of component (A) and the component
The resin composition blended with the block copolymer (B) can be produced by any conventionally known blending method. For example, melt-kneading methods using common mixers such as open rolls, intensive mixers, internal mixers, co-kneaders, continuous kneaders with twin-screw rotors, extruders, etc.; A method of removing the particles by heating is used. The resin composition of the present invention thus obtained can be processed into sheets, foams, etc. by any conventionally known molding method, such as extrusion molding, injection molding, and blow molding.
Films, injection molded products of various shapes, hollow molded products,
It can be easily molded into a wide variety of practically useful products such as pressure-formed products and vacuum-formed products. [Examples] In order to explain the present invention in more detail, Examples of the present invention are shown below, but it goes without saying that the content of the present invention is not limited to these Examples. Production of block copolymer In a nitrogen atmosphere, in a cyclohexane solvent using n-butyllithium as a solvent, approximately ₁ part of B monomer was added according to the monomer amounts shown in Table 1.
Polymerization was carried out at 70°C, and after the monomer was substantially completely polymerized, ₁ part of monomer A was added and polymerized. After the added monomers were substantially completely polymerized, ₃ parts of B ₂ , A ₂ and B were sequentially polymerized in the same manner to obtain a linear block copolymer. On the other hand, the radial type block copolymer
After sequentially polymerizing B ₁ , A ₁ , B ₂ and A ₂ in the same manner as above according to the monomer amounts shown in the table, 1/4 of the amount of n-butyllithium used in the polymerization was added. It was produced by adding mol of silicon tetrachloride base and causing a coupling reaction. The number average molecular weights of these block copolymers are shown in Table 3. In Tables 1 and 2, a step in which the amount of monomer charged is 0 means that the polymerization in that step was omitted. Further, when a mixed monomer of butadiene and styrene was used in forming the elastomeric block, 1 part by weight of tetrahydrofuran was used as a randomizing agent per 100 parts by weight of the total monomers used. Each of the obtained block copolymers contained 2,4-di-tert-butyl-p-cresol as a stabilizer,
Trisnonylphenyl phosphorite and phenothiazine were each added in an amount of 0.5 parts by weight per 100 parts by weight of the block copolymer.

【table】

【table】

【table】

【table】

【table】

[Table] Examples 1 to 8 and Comparative Examples 1 to 7 Intrinsic viscosity [η] is 0.65 (30°C in chloroform)
50 parts by weight of poly(2,6-dimethyl-1,4-phenylene) ether, 40 parts by weight of Styron 685 (manufactured by Asahi Kasei) as a styrene resin, 3.5 parts by weight of the block copolymer shown in Table 4, 2 parts by weight of antimony trioxide as a flame retardant, 2.5 parts by weight of decabromotetralin, and Sumirider as a stabilizer.
BHT (manufactured by Sumitomo Chemical) 1 part by weight, Sumilizer
Blend 1 part by weight of BBM (manufactured by Sumitomo Chemical) and use a twin-screw vented extruder to achieve maximum cylinder temperature.
Pellets were obtained by extrusion at 290°C, and test pieces were prepared using an injection molding machine at 290°C, and their properties were investigated. The results are shown in Table 4, and it can be seen that the thermoplastic resin composition containing the block copolymer defined by the present invention is excellent in impact resistance, stress cracking properties, and gloss.

【table】

[Table] Examples 9 to 11 and Comparative Examples 8 and 9 Thermoplastic resins were prepared in the same manner as in Examples 1 to 8, except that the blending amounts of the block copolymer and Stylon 685 were as shown in Table 5. Compositions were prepared and the properties of each composition are shown in Table 5.

[Table] Examples 12 and 13 Intrinsic viscosity [η] is 0.68 (30°C in chloroform)
30 parts by weight of poly(2,6-dimethyl-1,4-phenylene) ether, 50 parts by weight of Leona 1300S (manufactured by Asahi Kasei) as a polyamide resin, and Dilarc, a styrene-maleic anhydride copolymer, as a styrene resin. 232 (manufactured by Alco Chemical) and 10 parts by weight of the block copolymer shown in Table 6 were blended and extruded using a twin-screw vented extruder at a maximum cylinder temperature of 290°C to form pellets. A test piece was prepared by injection molding at 290°C. The properties of the obtained test pieces are shown in Table 6.

[Table] Example 14 Intrinsic viscosity [η] is 0.55 (30°C in chloroform)
50 parts by weight of poly(2,6-dimethyl-1,4-phenylene) ether, HIPS (polybutadiene dissolved in styrene monomer and bulk polymerized,
20 parts by weight of rubber-modified high-impact polystyrene with a polybutadiene content of 6%, Styron 685
10 parts by weight, Santec F- as polyethylene
2135 (manufactured by Asahi Kasei) 3 parts by weight, block copolymer 9
15 parts by weight of the above-mentioned stabilizer and 2 parts by weight of the above-mentioned stabilizer were blended, and an injection molded piece was prepared in the same manner as above, and its properties were measured. The tensile strength of the specimen is 450
Kg/cm ² , and the Izod impact value was 23.2 Kg/cm 2 . Example 15 Glass fiber (manufactured by Nittobo Co., Ltd., trade name: CS6PA-) was added to 100 parts by weight of the thermoplastic resin composition of Example 12.
After blending 43 parts by weight of 401), the mixture was kneaded using a twin-screw extruder and pelletized. After that, it was injection molded and its properties were investigated, and it was found that the flexural modulus was 95000Kg/cm ² , the Izotsu impact strength was 16.0Kg・cm/cm, and the heating deformation temperature
It was 230℃. Example 16 In the method for producing block copolymer 2, in Step 5, 35 parts by weight of butadiene was polymerized instead of 15 parts by weight, then in Step 6, 15 parts by weight of styrene was polymerized, and then in Step 7, 35 parts by weight of butadiene was polymerized. Polymerize 15 parts by weight of butadiene,
The final block copolymer MI(G) is 2
g/10 min, the polymer structure was changed to general formula B (-A
-B) Block copolymer 16 represented by ₃ was produced. Next, a thermoplastic resin composition was prepared in the same manner as in Example 2 except that block copolymer 16 was used instead of block copolymer 2. The resulting composition had a dart impact strength of 75 kg-cm or more, a stress crack resistance of 65 hours, and a gloss of 73%. [Effects of the Invention] The thermoplastic resin composition of the present invention exhibits extremely excellent impact resistance and also maintains the rigidity and heat resistance that are characteristics of polyphenylene ether resins. This eliminates problems such as cracking during mold release even when molded using injection molding methods using pin gates or hot runners, further expanding the range of applications for polyphenylene ether resins.

Claims (1)

[Scope of Claims] 1 (A) 60 to 99 parts by weight of polyphenylene ether resin (B) The following general formula (a) B ₁ −A ₁ −B ₂ (—A−B) _o —A ₂ -B ₃ (B) [B ₁ -A ₁ -B ₂ (-A-B) _o --] _n+2 ---X (C) [B ₁ -A ₁ -B ₂ (-A-B) _o --A] _n+2 ---
X (In the above formula, B, B ₁ , B ₂ and B ₃ are elastomeric blocks, A, A ₁ and A ₂ are non-elastomeric blocks, and X is silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, polyester It represents the residue of a coupling agent such as a carboxylic acid ester or the residue of an initiator such as a polyfunctional organolithium compound. m and n are 0 or an integer of 1 to 5. A non-elastomeric block is composed of a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene and/or a conjugated diene homopolymer with a vinyl aromatic hydrocarbon content of 50% or less by weight. is composed of a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene or/and a vinyl aromatic hydrocarbon homopolymer in which the amount exceeds 75% by weight.In addition, A, A ₁ , A ₂ or B, B ₁ , B ₂ , and B ₃ may have the same or different molecular weights, compositions, and microstructures.) at least three elastomeric blocks and at least two non-elastomeric blocks. A block copolymer consisting of a vinyl aromatic hydrocarbon and a conjugated diene in a weight ratio of 10:90 to 55:45 and a number average molecular weight of 10,000 to 1,000,000; All ends are elastomeric blocks (hereinafter referred to as chain-terminated elastomeric blocks), (ii) the content of chain-terminated elastomeric blocks in the polymer chain is 6 to 70% by weight, (iii) ) The content of elastomeric blocks in the polymer molecular chain other than the elastomeric block at the end of the molecular chain is 25% by weight or more, (iv) The total amount of the elastomeric block at the end of the molecular chain and the non-elastomeric block adjacent to this block. The content of molecular chain terminal elastomeric blocks at each end is
A thermoplastic resin composition having excellent impact resistance, comprising 1 to 40 parts by weight of a block copolymer of 10% by weight or more, and the total amount of components (A) and (B) being 100 parts by weight.