JP2002265748A - Block copolymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a block copolymer composition excellent in thermostability, and a composition consisting of this composition and a styrene resin excellent in a gel level (fish eye) and the balance of physical properties. SOLUTION: The block copolymer composition comprises: (I) a block copolymer composition comprising (a) a block copolymer comprising a vinyl aromatic hydrocarbon and 1,3-butadiene and (b) a block copolymer comprising a vinyl aromatic hydrocarbon and isoprene, or a vinyl aromatic hydrocarbon and isoprene and 1,3-butadiene, wherein a weight ratio of isoprene and 1,3-butadiene in the block copolymer composition is within a rang of 97/3-10/90; and the latter composition (II) comprises this block copolymer composition and the styrene resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The block copolymer composition of the present invention has a small change in molecular weight distribution due to cross-linking and breaking of polymer chains during heating at a high temperature, and can be used as a block copolymer composition or as a styrene-based block copolymer composition. Gel level (fish eye) when used as a composition with resin
The present invention provides various molded articles having good properties and excellent physical property balance.

[0002]

2. Description of the Related Art A block copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene represented by 1,3-butadiene having a relatively high content of a vinyl aromatic hydrocarbon has excellent transparency and impact resistance. Injection molded product applications utilizing such properties as
It is used for extruded products such as sheets and films. In particular, several proposals have been made on the block copolymer and the composition with the styrene-based polymer using the same because of their excellent transparency and mechanical properties. For example, Japanese Unexamined Patent Publication (Kokai) No. 52-58788 discloses a branched block copolymer in which a catalyst is divided and added for the purpose of improving transparency and impact resistance, and Japanese Unexamined Patent Publication (Kokai) No. 53-8688 discloses a thermally stable resin. Isoprene and 1,3
A production method in which butadiene is successively added is disclosed in
JP-A-13007 discloses a block copolymer having a specific structure having a polymer block mainly composed of isoprene in order to obtain an impact-resistant block copolymer.
In order to obtain a thermoplastic polymer composition having excellent appearance properties such as transparency and surface glossiness and impact resistance,
A composition of a block copolymer mixture and a thermoplastic resin having a composition distribution that changes with an increase in molecular weight is disclosed in
Japanese Unexamined Patent Publication (Kokai) No. 277509 discloses a method for producing a graded block copolymer in which a catalyst is divided and added to improve environmental stress cracking properties. In order to obtain an improved multilayer sheet made of a thermoplastic resin having a high rigidity, a multilayer sheet comprising a resin having a specific elastic modulus on the surface layer and a resin layer having a ratio of the resin to the Vicat softening point in a specific range is particularly required. 63-145
Japanese Patent Application Laid-Open No. 314/314 discloses a method for producing a block copolymer having an S1-B1-B / S-S2 structure in order to obtain excellent transparency and mechanical properties. In order to improve impact strength and reinforcing properties of vinyl aromatic hydrocarbon polymer, it is characterized by block ratio, arrangement of polymer blocks, ratio of conjugated diene in random copolymerized portion of vinyl aromatic hydrocarbon and conjugated diene, etc. And a composition thereof. However, a block copolymer composed of these vinyl aromatic hydrocarbons and a conjugated diene or a composition composed of the block copolymer and a styrene-based resin is used in applications such as forming a thin film and printing the thin film. However, the balance between fish eyes and physical properties, which are disadvantages during printing, is not sufficient, and these documents do not disclose a method for improving them, and still point out problems in the market.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a block copolymer composition having a small change in molecular weight distribution due to crosslinking and cleavage of a polymer chain during heating at a high temperature, a good gel level (fish eye) and an excellent balance of physical properties. And a composition comprising a block copolymer composition and a styrene-based resin.

[0004]

SUMMARY OF THE INVENTION The present inventors have developed a specific combination of block copolymers, namely, a block copolymer composed of vinyl aromatic hydrocarbon and 1,3-butadiene, a vinyl aromatic hydrocarbon and isoprene. The block copolymer composition comprising a block copolymer as a main component, and the composition comprising the styrene resin and the composition comprising a styrene-based resin are further combined with a specific stabilizer, thereby causing cross-linking and scission of polymer chains during high-temperature heating. The inventors have found that the change in the molecular weight distribution is small, the physical property balance is good, and the gel and fish eyes are significantly reduced, and the present invention has been completed.

That is, the present invention provides: (a) a polymer block mainly comprising at least two vinyl aromatic hydrocarbons and at least one polymer block mainly comprising 1,3-butadiene; Aromatic hydrocarbon content of 10 to 90% by weight, 1,3-
A block copolymer having a butadiene content of 90 to 10% by weight, (b) a polymer block mainly containing at least two vinyl aromatic hydrocarbons, (a) a polymer block mainly containing isoprene, B) Isoprene and 1,3
A copolymer block mainly composed of butadiene, (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon, and (d) a copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon. The copolymer block contains at least one polymer block selected from the group consisting of (a) to (d), and has a vinyl aromatic hydrocarbon content of 60.
And a block copolymer having a total content of isoprene and 1,3-butadiene of 40 to 5% by weight, the block copolymer composition comprising: A block copolymer composition, wherein the weight ratio of isoprene to 1,3-butadiene is in the range of 97/3 to 10/90,

(A) at least two polymer blocks mainly composed of vinyl aromatic hydrocarbons and at least one polymer block mainly composed of 1,3-butadiene, and a vinyl aromatic hydrocarbon content A block copolymer having 10 to 90% by weight and a 1,3-butadiene content of 90 to 10% by weight; (b) a polymer block mainly composed of at least two vinyl aromatic hydrocarbons; )
(D) a polymer block mainly composed of isoprene, (b) a copolymer block mainly composed of isoprene and 1,3-butadiene, (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon, At least one polymer block selected from the groups (a) to (d) of the copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon, and at least one 1,3-butadiene And / or at least one 1,3-butadiene and a copolymer block mainly composed of vinyl aromatic hydrocarbon, and the content of vinyl aromatic hydrocarbon is 60 to 95% by weight. , The combined content of isoprene and 1,3-butadiene is 40 to 5% by weight
And a weight ratio of isoprene and 1,3-butadiene in the block copolymer composition of 97/3 to 10 /.
A block copolymer composition characterized by being in the range of 90,

The weight ratio of isoprene to 1,3-butadiene in the block copolymer composition is 95/5 to 20/80.
A block copolymer composition characterized by the following range: 2- [1- (2-hydroxy-3,5-
Di-t-pentylphenyl) ethyl] -4,6-di-t
-Pentylphenyl acrylate, 2-t-butyl-6
Blocks at least one stabilizer selected from-(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate and 2,4-bis [(octylthio) methyl] -o-cresol Any of the following block copolymer compositions obtained by adding 0.05 to 3 parts by weight to 100 parts by weight of the copolymer composition, any of the block copolymer compositions 10 to 9
The present invention relates to a composition comprising 9% by weight and 90 to 1% by weight of a styrene resin.

Hereinafter, the present invention will be described in detail. The block copolymer of the component (a) and the component (b) of the present invention is obtained by polymerizing vinyl aromatic hydrocarbon with isoprene and 1,3-butadiene in a hydrocarbon solvent using an organic lithium compound as an initiator. What you get. Examples of the hydrocarbon solvent used for producing the block copolymer include butane, pentane, hexane, isopentane, heptane, octane,
Aliphatic hydrocarbons such as aliphatic hydrocarbons such as isooctane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane; and aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene. May be used alone or in combination of two or more.

The organic lithium compound used for the block copolymer is an organic monolithium compound, an organic dilithium compound, or an organic polylithium compound having one or more lithium atoms bonded in the molecule. Specific examples of these include ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium and the like. No. These may be used alone or in combination of two or more. As the vinyl aromatic hydrocarbon used for the block copolymer, styrene, o-methylstyrene,
p-methylstyrene, p-tert-butylstyrene,
There are 2,4-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene, and the like, and styrene is particularly common. These may be used alone or in combination of two or more.

The block copolymer of the component (a) of the present invention comprises at least two polymer blocks mainly composed of vinyl aromatic hydrocarbons and at least one polymer block mainly composed of 1,3-butadiene. A block copolymer comprising: (b) at least two vinyl aromatic hydrocarbon-based polymer blocks; and (a) isoprene-based polymer blocks. (B) a copolymer block mainly composed of isoprene and 1,3-butadiene, (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon,
(D) (a) to (c) of a copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon
At least one polymer block selected from the group (d)
Or a block copolymer containing at least two vinyl aromatic hydrocarbons, (a) a polymer block mainly containing isoprene, and (b) a polymer block mainly containing isoprene and 1,3-butadiene. (C) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbons,
(D) (a) to (c) of a copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon
At least one polymer block selected from the group (d)
And at least one polymer block based on 1,3-butadiene and / or at least one 1,3-butadiene
It is a block copolymer containing butadiene and a copolymer block mainly composed of a vinyl aromatic hydrocarbon.

[0011] These block copolymers include, for example, those of the following general formula. (1) A- (BA) n (2) A- (BA) n-B (3) a linear block copolymer represented by B- (AB) n + 1, or General formula (4) [(AB) k] m + 2-X (5) [(AB) k-A] m + 2-X (6) [(BA) k] m + 2 -X (7) A radial block copolymer represented by [(BA) k-B] m + 2 -X, preferably a linear block copolymer. (However, in the above formulas (1) to (7), A represents a polymer block mainly composed of vinyl aromatic hydrocarbon, and the polymer block of A has a vinyl aromatic hydrocarbon content of 70% by weight or more. And B represents a polymer block mainly composed of 1,3-butadiene in the case of the block copolymer of the component (a), and (B) in the case of the block copolymer of the component (b). A) a polymer block mainly composed of isoprene;
(B) a copolymer block mainly composed of isoprene and 1,3-butadiene, (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon, (d) isoprene, 1,3-butadiene and vinyl It shows at least one polymer block selected from (a) to (d) of the copolymer block mainly composed of an aromatic hydrocarbon. (B) a copolymer block mainly composed of isoprene and 1,3-butadiene; (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon;
At least one polymer block selected from (a) to (d) of a copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon;
Butadiene-based polymer block and / or 1,
3 shows a copolymer block mainly composed of 3-butadiene and vinyl aromatic hydrocarbon.

The polymer block of B is a polymer block mainly composed of 1,3-butadiene, or (a) a polymer block mainly composed of isoprene, or (ii) a polymer block mainly composed of isoprene and 1,3-butadiene. In the case of a copolymer block, the vinyl aromatic hydrocarbon content of the polymer block of B is less than 50% by weight, and the polymer block of B is (c) a copolymer mainly composed of isoprene and vinyl aromatic hydrocarbon. In the case of a united block, (d) a copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon, or a copolymer block mainly composed of 1,3-butadiene and vinyl aromatic hydrocarbon The vinyl aromatic hydrocarbon content of the polymer block of B is less than 70% by weight,
Preferably it is less than 60% by weight.

X is a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, tetraglycidyl-1,3-bisaminomethylcyclohexane, polyhalogenated hydrocarbon, carboxylic acid ester and polyvinyl compound. Indicates a group or a residue of an initiator such as a polyfunctional organolithium compound. n, k and m are integers of 1 or more, generally 1
~ 5. The block copolymer (a) has a vinyl aromatic hydrocarbon content of 10 to 90% by weight, more preferably 20 to 8% by weight.
5% by weight, the content of 1,3-butadiene is 90 to 10% by weight, more preferably 80 to 15% by weight.
The vinyl aromatic hydrocarbon content of the block copolymer (b) is 60 to 95% by weight, preferably 65 to 90% by weight, more preferably 65 to 85% by weight, and isoprene and 1,3-butadiene combined. The content is 40 to 5% by weight, preferably 35 to 10% by weight, more preferably 35% by weight.
１５15% by weight.

If the vinyl aromatic hydrocarbon content of the component (a) is less than 10% by weight and the 1,3-butadiene content is more than 90% by weight, the formation of a sheet or film in the case of a composition with a styrene resin If the transparency of the product is reduced, the content of the vinyl aromatic hydrocarbon is more than 95% by weight, and if the content of 1,3-butadiene is less than 5% by weight, elongation is caused and the impact resistance is reduced, which is not preferable. Component (b) has a vinyl aromatic hydrocarbon content of less than 60% by weight, and isoprene and 1,3-
If the total content of butadiene exceeds 40% by weight, when a composition with a styrene-based resin is used, the rigidity and transparency of sheets and films are reduced and the vinyl aromatic hydrocarbon content is reduced. If the content exceeds 95% by weight and the combined content of isoprene and 1,3-butadiene is less than 5% by weight, elongation is caused and the impact resistance is undesirably reduced.
(B) Isoprene in the block copolymer of component and 1,3
The butadiene content ratio is not particularly limited as long as it satisfies the weight ratio of isoprene and 1,3-butadiene in the block copolymer described later, but preferably the isoprene content is between isoprene and 1,3-butadiene. It is at least 20% by weight, more preferably at least 40%, based on the total content.

The preferred block ratio of the vinyl aromatic hydrocarbon polymer block incorporated in the block copolymer (a) or (b) used in the present invention is 50% by weight.
That is all. If the block ratio is less than 50%, the rigidity of the sheet is poor, which is not preferable. The block ratio of the vinyl aromatic hydrocarbon block is determined by comparing the vinyl aromatic hydrocarbon with 1,3-butadiene and / or isoprene in the step of copolymerizing 1,3-butadiene and / or isoprene during the production of the block copolymer. -It can be controlled by changing the weight, weight ratio, polymerization reactivity ratio and the like of butadiene and / or isoprene. As a specific method, a mixture of a vinyl aromatic hydrocarbon and 1,3-butadiene and / or isoprene is continuously supplied to a polymerization system to carry out polymerization, or a vinyl compound is produced by using a polar compound or a randomizing agent. A method such as copolymerizing an aromatic hydrocarbon with 1,3-butadiene and / or isoprene can be employed. Examples of polar compounds and randomizing agents include tetrahydrofuran, diethylene glycol dimethyl ether, ethers such as diethylene glycol dibutyl ether, amines such as triethylamine, tetramethylethylenediamine, thioethers, phosphines, phosphoramides, alkylbenzene sulfonates, potassium and sodium salts. Alkoxide and the like.

In the present invention, the block ratio of the vinyl aromatic hydrocarbon polymer block incorporated in the block copolymer is determined by using osmium tetroxide as a catalyst.
A method of oxidatively decomposing a block copolymer with tertiary butyl hydroperoxide (IM KOLTH)
OFF, et al. , J. et al. Polym. Sci. 1,4
29 (1946)) (in which the average degree of polymerization is about 3).
0 or less of the vinyl aromatic hydrocarbon polymer component is excluded), and the value obtained from the following formula is referred to. Block ratio (% by weight) = A / B × 100 (A is the weight% of the vinyl aromatic hydrocarbon polymer block in the block copolymer, and B is the weight% of the total vinyl aromatic hydrocarbon in the block copolymer. Is.)

The polymerization temperature for producing the block copolymer of the present invention is generally -10 ° C to 150 ° C, preferably 4 ° C.
0 ° C to 120 ° C. The time required for the polymerization varies depending on the conditions, but is usually within 10 hours, particularly preferably 0.5 to 5 hours. Further, it is desirable to replace the atmosphere of the polymerization system with an inert gas such as nitrogen gas. The polymerization pressure is not particularly limited, as long as it is a pressure range sufficient to maintain the monomer and the solvent in a liquid phase within the above-mentioned polymerization temperature range. Furthermore, it is necessary to take care that impurities such as water, oxygen, carbon dioxide, etc. which inactivate the catalyst and the living polymer do not enter the polymerization system.

The preferred MFR of the block copolymer (at 200 ° C. under a G condition and a load of 5 kg) is from 0.1 to 50 g / 10 min, preferably from 1 to 25 g / min.
10 min. It is. The weight ratio of isoprene to 1,3-butadiene in the block copolymer composition is 97/3 to 10
/ 90, preferably 95/5 to 20/80, more preferably 90/10 to 45/55. When the weight ratio of isoprene to 1,3-butadiene in the block copolymer composition exceeds 97/3, the change in the molecular weight distribution due to the breakage of the polymer chains during high-temperature heating increases, and the fluidity during processing increases. And the like, which is not preferable. Conversely, if the weight ratio of isoprene to 1,3-butadiene is less than 10/90, the change in the molecular weight distribution due to the crosslinking of the polymer chains at the time of heating at a high temperature becomes large, resulting in gelation, which is not preferable.

The block copolymer composition of the present invention contains 2- [1- (2-hydroxy-3,5-di-) as a stabilizer.
t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, 2-t-butyl-6-
Block-forming at least one stabilizer selected from (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate and 2,4-bis [(octylthio) methyl] -o-cresol. By adding 0.05 to 3 parts by weight, preferably 0.1 to 2 parts by weight, to 100 parts by weight of the polymer composition, it is possible to obtain a further higher thermal stability effect at the time of high temperature heating. When the amount of the stabilizer is less than 0.05 part by weight, the effect of suppressing the change in the molecular weight distribution due to the crosslinking and cleavage of the polymer chain at the time of high temperature heating is small, and adding more than 3 parts by weight does not contribute to the effect of the present invention. . The block copolymer composition of the present invention comprises n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tetrakis [methylene-3- (3,5-di-t- Butyl-4-
Hydroxyphenyl) propionate] methane, 1,
3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene,
2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,3
At least one phenolic stabilizer such as 5-triazine;
The seed is added in an amount of 0.1 to 100 parts by weight of the block copolymer composition.
05 to 3 parts by weight, tris- (nonylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphite, 2-[[2,
4,8,10-tetrakis (1,1-dimethylethyl)
Dibenzo [d, f] [1,3,2] dioxaphosphefin-6-yl] oxy] -N, N-bis [2-
[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphefin-6-yl] oxy] -ethyl] -ethanamine, Tris (2,4-di-t-butylphenyl)
At least one of an organic phosphate-based stabilizer such as phosphite and an organic phosphite-based stabilizer can be added in an amount of 0.05 to 3 parts by weight based on 100 parts by weight of the block copolymer composition.

These stabilizers may be added during the step of producing the block copolymer of the component (a) and the component (b).
It can also be added in the kneading step of the component (a) and the component (b), or in the extrusion and molding steps. By making the block copolymer composition of the present invention a composition with a styrene resin,
The balance of physical properties can be further improved.

As the styrene resin used in the present invention, a non-rubber-modified styrene polymer and a rubber-modified styrene polymer can be used. Non-rubber modified styrenic polymer is
Styrene, α-alkyl-substituted styrenes such as α-methylstyrene, nucleus alkyl-substituted styrenes, nucleus halogen-substituted styrenes and the like, at least one styrene-based polymer, at least one selected from the styrene monomers It is a copolymer with at least one other monomer described below that can be copolymerized with one of these monomers containing 50 to 70% by weight or more. Specifically, the monomers copolymerizable with the styrene monomer include acrylic acid and esters thereof (for example, alkyl alcohols such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate). Esters having 1 to 12 carbon atoms), methacrylic acid and esters thereof (e.g., esters having the same alcohol components as those described above such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate), fumaric acid,
Α, β-unsaturated dicarboxylic acids such as maleic acid and itaconic acid and their monoesters, diesters, anhydrides and imidates (eg maleic anhydride, maleimide, etc.)
And the like. Suitable styrenic resins are polystyrene, styrene-n-butyl acrylate copolymer, styrene-methyl methacrylate copolymer, and the like, and rubber-modified polymers thereof. These can be used alone or as a mixture of two or more.

The composition of the present invention comprises 10 to 99% by weight of a block copolymer composition and 90 to 1% by weight of a styrene resin.
Preferably, the composition comprises 10 to 90% by weight of the block copolymer composition and 90 to 10% by weight of the styrene resin, and more preferably 15 to 85% by weight of the block copolymer composition and 85 to 15% by weight of the styrene resin. It is. When the content of the block copolymer composition is less than 10% by weight and the content of the styrene resin is more than 90% by weight, the impact resistance is reduced, and the content of the block copolymer composition exceeds 99% by weight and the content of the styrene resin is 1% by weight. If it is less than the above range, the effect of improving the surface properties (slipperiness, blocking resistance, etc.) and rigidity of the molded product by blending the styrene resin is not preferred. The 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 equipped with a twin-screw rotor, a melt kneading method using a general kneader such as an extruder, etc. And the like are used.

Various additives can be added to the composition of the present invention, if necessary. These additives include, in addition to a hydrogenated product of a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene, polyethylene terephthalate, polyphenylene ether, and the like, additives generally used for blending plastics, for example, glass. Inorganic reinforcing agents such as fiber, glass beads, silica, charcoal, talc, etc., organic fibers, organic reinforcing agents such as coumarone indene resin, crosslinking agents such as organic peroxides and inorganic peroxides, titanium white, carbon black, iron oxide Pigments, dyes, flame retardants, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, plasticizers, other extenders, and mixtures thereof. The composition of the present invention can be used as it is or after being colored and molded by the same processing means as ordinary thermoplastic resins, and used for various purposes. For example, O by injection molding, blow molding, etc.
A It can be used for containers for equipment parts, daily necessities, food, miscellaneous goods, weak electric parts and the like. In particular, it is suitable for thin films such as heat-shrinkable films and laminating films, or transparent sheet molded products such as blister cases such as foodstuffs and weakly electric parts, taking advantage of the characteristics of good gel level (fish eye) and excellent balance of physical properties. is there.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but they do not limit the scope of the present invention. Table 1 shows the styrene content (% by weight), the block ratio (%), the polymer structure, the type and amount of the stabilizer added (parts by weight) of the block copolymers used in Examples and Comparative Examples, and Table 2 shows styrene. The system resin is shown.

The block copolymer was polymerized in a cyclohexane solvent using n-butyllithium as an initiator and adding the monomers in the order and amount shown in the polymer structure column of Table 1. For example, the block copolymer A-1 was produced as follows. A cyclohexane solution containing 22 parts by weight of styrene at a concentration of 20% by weight was charged into a jacketed 30L closed reactor, and 0.08 parts by weight of n-butyllithium was added thereto. 3
Polymerization was carried out at 80 ° C. for 20 minutes while maintaining at ５5 kg / cm ² G. Thereafter, a cyclohexane solution containing 30 parts by weight of 1,3-butadiene and 13 parts by weight of styrene at a concentration of 20% by weight was continuously added and polymerized at 80 ° C. for 45 minutes, and then 35 parts by weight of styrene was added at a concentration of 20% by weight. Was added continuously to carry out polymerization at 80 ° C. for 35 minutes. Then, after equimolar addition to n-butyllithium using methanol in the reactor and stirring for 3 minutes, a stabilizer was added and the solvent was removed to remove the block copolymer A- containing the stabilizer. 1 was collected. Regarding the production of the block copolymers A-2 to A-5, except that the block copolymer A-3 was added 0.25 times by mol to n-butyllithium using silicon tetrachloride before adding methanol. It was manufactured in the same manner as in A-1.

B-1 was charged with a cyclohexane solution containing 8 parts by weight of isoprene at a concentration of 20% by weight in a 30 L closed reactor equipped with a jacket, and 0.085 parts by weight of n-butyllithium was added thereto. Is replaced with nitrogen gas and the pressure is maintained at ³ to 5 kg / cm ² G while 80
Polymerized at 20 ° C for 20 minutes. Then 21 parts by weight of styrene were added to 2
A cyclohexane solution containing 0% by weight is added at a time and polymerized at 80 ° C. for 20 minutes, and then a cyclohexane solution containing 3 parts by weight of isoprene at a concentration of 20% by weight is added all at once and polymerized at 80 ° C. for 10 minutes. And then isoprene 1
A cyclohexane solution containing 9 parts by weight and 5 parts by weight of styrene at a concentration of 20% by weight was polymerized at 80 ° C. while continuously adding over 30 minutes, and then cyclohexane containing 44 parts by weight of styrene at a concentration of 20% by weight was added. The solution was added all at once and polymerized at 80 ° C. for 35 minutes. Thereafter, in a reactor, an equimolar amount was added to n-butyllithium using methanol, and the mixture was stirred for 3 minutes. Then, a stabilizer was added, and the solvent was removed to remove the block copolymer B containing the stabilizer. -1
Was recovered.

For the production of the block copolymers B-2 to B-11, the block copolymers B-4, B-6, and B-11 were prepared using n-silicon tetrachloride before adding methanol.
It was produced in the same manner as in B-1 except that it was added in an amount of 0.25 times the mol of butyllithium. The block copolymers A-1 to A-5 and B-1 to B-11 all have an MFR of 5
-20 (g / 10 min.). MFR
Was measured at a temperature of 200 ° C. and a load of 5 kg (condition 8) in accordance with JIS K-7210. The content (% by weight) of the polystyrene block in the block copolymer is determined by decomposing the block copolymer with osmic acid, reprecipitating in methanol, measuring the weight of the precipitate, and measuring the weight of the polystyrene in the block copolymer. The block amount was divided by the total styrene amount to determine the block ratio (% by weight).

C-1 has an MFR of 2.1 (g / 10 mi)
n. ) Is a general-purpose polystyrene (manufactured by A & M Styrene Co., Ltd.). C-2 copolymer was added to styrene and acrylic acid n-
5 kg of butyl was added at the ratio shown in Table 1, and 0.3 kg of ethylbenzene and a predetermined amount of 1,1 bis (t-butylperoxy) cyclohexane for adjusting MFR were charged at 110 to 150 ° C. for 2 to 10 hours. After polymerization, unreacted styrene, n-butyl acrylate, and ethylbenzene were recovered by a vent extruder to obtain. MFR of C-2 is 3.0
(G / 10 min.).

[0029]

Examples 1 to 11 In accordance with the composition shown in Table 3, the block copolymer shown in Table 1 and the styrene resin shown in Table 2 were used to extrude at a temperature of 210 with a 40 mm sheet extruder.
A sheet with a thickness of 0.30 mm is formed at ℃, tensile modulus,
Elongation at break and Haze were measured by the following methods. Further, a sheet having a thickness of 0.6 mm was formed under the same conditions, and the surface impact strength was measured by the following method. Table 3 shows the performance of the obtained sheet. (1) Tensile modulus and elongation at break: Measured in accordance with ASTM D638 at a tensile speed of 5 mm / min in a film extrusion direction and a direction perpendicular thereto. The test piece has a width of 1
2.7 mm and the distance between the marked lines was 50 mm. (2) Surface impact strength: Measured at 23 ° C. in accordance with ASTM D-1709 except that the weight was changed to a radius of 1/2 inch, and a 50% breaking value was obtained.

(3) Haze: Liquid paraffin was applied to the surface of the film, and measured according to ASTM D1003. (4) Fisheye (FE): A sheet having a thickness of 0.3 mm was continuously formed using a 40 mm sheet extruder at an extrusion temperature of 230 ° C. for 6 hours, and a sheet area of 300 cm after 5 minutes and 6 hours from the start of operation. 0.5mm or more FE per ²
The number difference was counted and evaluated (評 価: difference is less than 50, Δ: difference is 50 to 100, ×: difference is more than 100). (5) Thermal stability: The block copolymer composition shown in Table 3 was heated to a temperature of 225 ° C. in a nitrogen atmosphere and allowed to stand for 80 minutes. The molecular weight distribution of this block copolymer was measured by gel permeation chromatography (GPC),
The molecular weight distribution was superimposed on the same area as the molecular weight distribution before the heating and standing, and the difference between the low molecular weight ratio (standard for polymer chain cleavage) and the high molecular ratio (standard for polymer chain crosslinking) was expressed in terms of% by weight.

[0031]

Examples 12 to 15 and Comparative Examples 1 to 10 In the same manner as in Example 1 except that the block copolymer shown in Table 1 and the styrene resin shown in Table 2 were used according to the composition shown in Table 4. , And the tensile modulus, elongation at break, and haze were measured in the same manner as in Example 1. Further, a sheet having a thickness of 0.6 mm was formed under the same conditions, and the surface impact strength was measured in the same manner as in Example 1. Table 4 shows the performance of the obtained sheet.

[0032]

Example 16 In the composition of Example 1, 15% by weight of the block copolymer A-1 and 35% by weight of the block copolymer B-2 were used.
% By weight and 50% by weight of styrene resin C-2 at 40 mm
0.25m thickness at 210 ° C extrusion temperature by sheet extruder
m sheet, and heat-shrinkable film at 80 ° C
The shrinkage (a measure of low-temperature shrinkage), the natural shrinkage, and the hot water fusibility were measured by the following methods. As a result, the heat shrinkage at 80 ° C. was 67%, the natural shrinkage was 0.2%, and the hot water fusion property was good, indicating good heat shrinkage characteristics. (6) Shrinkage at 80 ° C .: A film having a thickness of about 60 μm obtained by uniaxially stretching a sheet having a thickness of 0.25 mm five times by a tenter stretching machine in a direction perpendicular to the extrusion direction is heated at a temperature of 80 ° C. in hot water. Immersed for 2 minutes and calculated by the following equation. Heat shrinkage (%) =
(L−L1) / L × 100, L: length before shrinkage, L1:
Length after shrinkage.

(7) Natural shrinkage: 80% shrinkage of 40%
Was allowed to stand at 35 ° C. for 5 days and calculated by the following equation. Natural shrinkage (%) = (L2−L3) / L2 × 1
00, L2: length before standing, L3: length after standing. (8) Hot water fusion property: The stretched film was wound around a glass bottle having a diameter of about 8 cm, left in a stack of three bales in 70 ° C. warm water for 5 minutes, and the fusion state of the film was visually judged. The criterion is that ◎ indicates that no fusion has occurred, ○ indicates that fusion has occurred slightly, but will be separated immediately, and X indicates that fusion will not occur immediately.

[0034]

Example 17: 10% by weight of block copolymer A-1
30% by weight of block copolymer B-2, 55% by weight of styrene resin C-2, and high impact polystyrene 47
5D (A & M Styrene Co., Ltd., MFR
2.0 g / 10 min. 5% by weight using a 40 mm sheet extruder at an extrusion temperature of 230 ° C. and a thickness of 0.3 mm
Was continuously formed for 6 hours, and the difference between the number of FEs of 0.5 mm or more per 300 cm ² of sheet area at 5 minutes and 6 hours after the start of operation was counted and evaluated. 50 FEs
A sheet having less than the number of fish eyes and less occurrence of fish eyes was obtained.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

The block copolymer composition of the present invention has a small change in the molecular weight distribution due to crosslinking and cutting of polymer chains at the time of heating at a high temperature, and the sheet or film of the block copolymer composition or the block copolymer composition. Sheets and films molded using the composition of the product and the styrene-based resin have less fish eyes (FE) and are excellent in balance between transparency, tensile modulus and surface impact strength. Further, the heat-shrinkable film has low FE and good low-temperature shrinkability. By taking advantage of such a low FE feature, an extruded product such as a thin sheet or film can be suitably used as a wrapping film, or as a laminated film for a foam container or the like, or as a heat-shrinkable film.

Continuation of front page (72) Inventor Yukio Yamaura 1-3-1 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Asahi Kasei Corporation 4J002 BC03Y BC04Y BP01W BP01X EJ066 EV026 FD036

Claims (5)

[Claims] 1. A vinyl aromatic hydrocarbon containing at least two polymer blocks mainly composed of vinyl aromatic hydrocarbons and at least one polymer block mainly composed of 1,3-butadiene. A block copolymer having a content of 10 to 90% by weight and a 1,3-butadiene content of 90 to 10% by weight, and (b) a polymer block mainly containing at least two vinyl aromatic hydrocarbons; (I)
(D) a polymer block mainly composed of isoprene, (b) a copolymer block mainly composed of isoprene and 1,3-butadiene, (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon, A copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon, containing at least one polymer block selected from the group consisting of (a) to (d), containing vinyl aromatic hydrocarbon A block copolymer composition comprising a block copolymer having an amount of 60 to 95% by weight and a total content of isoprene and 1,3-butadiene of 40 to 5% by weight. Isoprene in the coalescing composition and 1,3
-A block copolymer composition wherein the weight ratio of butadiene is in the range of 97/3 to 10/90. 2. A vinyl aromatic hydrocarbon containing (a) at least two polymer blocks mainly composed of vinyl aromatic hydrocarbons and at least one polymer block mainly composed of 1,3-butadiene. A block copolymer having a content of 10 to 90% by weight and a 1,3-butadiene content of 90 to 10% by weight, and (b) a polymer block mainly containing at least two vinyl aromatic hydrocarbons; (I)
(D) a polymer block mainly composed of isoprene, (b) a copolymer block mainly composed of isoprene and 1,3-butadiene, (c) a copolymer block mainly composed of isoprene and vinyl aromatic hydrocarbon, At least one polymer block selected from the groups (a) to (d) of the copolymer block mainly composed of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon, and at least one 1,3-butadiene And / or at least one 1,3-butadiene and a copolymer block mainly composed of vinyl aromatic hydrocarbon, and the content of vinyl aromatic hydrocarbon is 60 to 95% by weight. , The combined content of isoprene and 1,3-butadiene is 40 to 5% by weight
And a weight ratio of isoprene and 1,3-butadiene in the block copolymer composition of 97/3 to 10 /.
90. A block copolymer composition having a range of 90. 3. The weight ratio of isoprene to 1,3-butadiene in the block copolymer composition is 95/5 to 20/80.
The block copolymer composition according to claim 1 or 2, wherein 4. As a stabilizer, 2- [1- (2-hydroxy-3,5-di-t-pentylphenyl) ethyl]-
4,6-di-t-pentylphenyl acrylate, 2-
t-butyl-6- (3-t-butyl-2-hydroxy-
At least one stabilizer selected from 5-methylbenzyl) -4-methylphenyl acrylate and 2,4-bis [(octylthio) methyl] -o-cresol is added in an amount of 0 to 100 parts by weight of the block copolymer composition. The block copolymer composition according to any one of claims 1 to 3, which is added in an amount of 0.05 to 3 parts by weight. 5. The block copolymer composition according to claim 1, wherein the styrene resin is 10 to 99% by weight.
A composition comprising 0 to 1% by weight.