JPH072889B2 - Thermoplastic elastic composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition for footwear having improved physical properties without lowering fluidity.

More specifically, an end-modified block copolymer obtained by reacting a block copolymer consisting of a conjugated diene having an alkali metal atom bonded to the polymer chain end and a vinyl aromatic compound and a specific sulfur-containing compound or phosphorus-containing compound The present invention relates to a thermoplastic elastomer composition for footwear, which is made of a polymer and is improved in tensile strength, elongation, impact resilience, abrasion resistance, oil resistance, and flex resistance without lowering fluidity.

[Prior Art] Various materials have been conventionally used as materials for shoe soles. Natural rubber and SBR are rubbers with well-balanced physical properties, but they require a vulcanization process and are costly. Also,
Polyurethane rubber having excellent physical properties can be used unvulcanized, but is more expensive. On the other hand, the soft vinyl chloride resin is inexpensive but has poor physical properties such as thermal stability, low temperature characteristics and slip resistance. As described above, the conventional materials have a problem in the balance between economic efficiency and performance.

On the other hand, styrene-butadiene block copolymer rubber (hereinafter abbreviated as SB TR) is an excellent thermoplastic elastic body that does not have these drawbacks. Thermoplastic elastomers are essentially different from the rubbers commonly used in the rubber industry and show good rubber-like properties without the need for a vulcanization step.
That is, it has the characteristics that it has fluidity at high temperatures like ordinary thermoplastic resins, can be easily molded by an ordinary plastic molding machine, and exhibits good rubber-like properties when returned to room temperature.

However, SB-based TRs are significantly inferior in fluidity to ordinary thermoplastic resins, and moreover, they are prone to thermal deterioration at high temperatures, so it is difficult to raise the processing temperature during molding to improve fluidity. Therefore, generally, process oil is added to improve fluidity. However, addition of only the process oil improves the fluidity but decreases the hardness, and also significantly lowers the tensile strength. Therefore,
Generally, to maintain fluidity and physical properties at the same time,
A method of blending a polystyrene resin, an inorganic filler, etc. in addition to the process oil has been adopted, but the fluidity and hardness are improved, but the decrease in tensile strength is not sufficiently improved.

Recently, from the aspects of comfort and practicality, improvement of impact resilience, abrasion resistance, and flex resistance to rubber for soles has been desired, but conventional rubber for soles using SB type TR is sufficient. Is not satisfied with.

In addition, SB-based TR is not chemically crosslinked like vulcanized rubber, so its oil resistance is extremely inferior, and when it is used as a rubber for shoe soles, it also has the drawback that the shoe soles are significantly deteriorated and worn.

Many attempts have been made to improve these problems.
In JP-A-60-170650, by using SB-type TR as a specific composition composed of 1,2-polybutadiene or the like, a composition excellent in hardness, fluidity, appearance of molded article, flex resistance and ozone resistance is obtained. However, the effect of improvement is insufficient, and the effect of improving impact resilience, oil resistance, and abrasion resistance is not disclosed. In JP-A-59-223744, SB system T
Although it has been disclosed that the oil resistance can be improved by adding an acrylic copolymer to R, it has a problem that tensile strength and elongation are lowered. Further, in U.S. Pat.No. 4,409,357, a polyvinyl aromatic compound is used as a coupling agent, a branched SB TR is formed, and a block copolymer in which a polar group is bonded to the branch point is used to improve the fluidity. However, the improving effect is not sufficient, and the improving effects such as tensile strength and impact resilience are not disclosed.

[Problems to be Solved by the Invention] In view of the above points, the present invention is heat for footwear that simultaneously satisfies tensile strength, elongation, impact resilience, wear resistance, oil resistance, and flex resistance without lowering fluidity. An object is to provide a plastic elastic composition.

[Means and Actions for Solving Problems] As a result of intensive studies to solve the above problems, the present inventors have surprisingly found that an alkali metal atom is bonded to the polymer chain terminal. The inventors have found that the object of the present invention can be achieved by using an end-modified block copolymer obtained by reacting a block copolymer with a specific sulfur-containing compound or phosphorus-containing compound, and completed the present invention.

That is, the present invention is (a) a block copolymer comprising at least two vinyl aromatic compound-based polymer blocks and at least one conjugated diene-based polymer block, A block copolymer having an alkali metal atom bonded to the polymer chain terminal, i) a sulfonic acid derivative having at least one SO ₂ bond in the molecule or a sulfone ii) a sulfinic acid derivative having at least one SO bond in the molecule Or a sulfoxide iii) a thioether or a cyclic sulfide having at least one S bond in the molecule iv) a phosphoric acid derivative v) a phosphorous acid derivative, and a terminal obtained by reacting with a sulfur-containing compound or a phosphorus-containing compound selected from the group consisting of 100 parts by weight of a thermoplastic elastomer which is a modified block copolymer, and (b) a process in which the viscosity specific gravity constant is 0.900 or less. Yl 1
A thermoplastic elastomer composition for footwear comprising 0 to 200 parts by weight, (c) 10 to 150 parts by weight of an inorganic filler, and (d) 0 to 120 parts by weight of a polystyrene resin. .

The present invention will be described in detail below.

The thermoplastic elastomer used in the present invention comprises an alkali metal or organic alkali metal compound as a polymerization initiator, and at least one polymer obtained by block copolymerizing a conjugated diene and a vinyl aromatic compound. It is obtained by reacting an atom-bonded block copolymer with a specific sulfur-containing compound or phosphorus-containing compound.

In the present invention, the above composition using an end-modified block copolymer obtained by reacting a block copolymer in which an alkali metal atom is bonded to the polymer chain terminal and a specific sulfur-containing compound or phosphorus-containing compound, Since the residue of the sulfur-containing compound or the phosphorus-containing compound bonded to the polymer chain terminal by modification has a polar portion, the affinity for the surface of the inorganic filler becomes strong when the inorganic filler is added, and the sulfur-containing compound is Alternatively, the tensile strength, impact resilience, etc. are improved as compared with a composition using a block copolymer in which the residue of the phosphorus-containing compound is not bonded. However, at high temperatures, this action is weakened by thermal motion, and fluidity during molding and processing is not impaired.

Further, the effect of the residue of the sulfur-containing compound or the phosphorus-containing compound being bonded to the end of the block copolymer chain has the effect of increasing tensile strength and elongation as compared with the case of bonding to the center of the polymer chain. It has excellent oil resistance, impact resilience, and flex resistance.

These are achieved only by attaching a residue of a specific sulfur-containing compound or phosphorus-containing compound to the polymer chain terminal.

Any known method may be used as a method for producing a block copolymer composed of a conjugated diene having an alkali metal atom bonded to at least one polymer chain end used in the present invention and a known method, for example, JP-B-36-19286. Bulletin,
Japanese Patent Publication No. 48-2423, Japanese Patent Publication No. 48-4106, Japanese Patent Publication No. 49
-36957, etc. are mentioned. That is,
In this method, an organolithium compound or the like is used as an anionic polymerization initiator in an inert hydrocarbon solvent to block-copolymerize a conjugated diene and a vinyl aromatic compound.

The block bonding mode in the block copolymer used in the present invention is represented by the following general formula as an example.
It is not limited to these.

General formula AB-A) n _-1 , (AB) n, (A-BnR (wherein A is a polymer block mainly containing a vinyl aromatic compound, B is a polymer block mainly containing a conjugated diene,
R represents a polyfunctional organic alkali metal initiator residue, and n represents an integer of 2 or more. ) A and B can change their structure to the extent that they do not essentially impair their physical and chemical properties. For example, in a block mainly composed of a vinyl aromatic compound A,
It may have a structure in which conjugated dienes are arranged substantially randomly, or may have a structure in which a vinyl aromatic compound is arranged substantially randomly in a block containing B as a main component. In addition, the block A may be a complete block or a tapered block.

The block copolymer used in the present invention may be any mixture of the block copolymers represented by the above general formula.

The vinyl aromatic compound content in the block copolymer used in the present invention is preferably in the range of 10 to 60% by weight,
It is particularly preferably in the range of 20 to 50% by weight. If it is less than 10% by weight, the tensile strength is insufficient, which is not preferable, and if it exceeds 60% by weight, the rubber elasticity is significantly lowered, which is not preferable.

Further, the weight average molecular weight in terms of standard polystyrene determined by gel permeation chromatography of the block copolymer is preferably in the range of 30,000 to 500,000. Furthermore, when the conjugated diene block in the block copolymer is polybutadiene, the microstructure preferably has a 1,2-vinyl content of 8 to 45%. This uses an infrared spectrophotometer and the method of Hampton (Analytical C
hem., 21 , 943 (1943)).

Examples of the vinyl aromatic compound used in the present invention include styrene, p-methylstyrene, α-methylstyrene and p-te.
Examples include rt-butyl styrene, styrene and p-
Methylstyrene is preferred. These may be used alone or in combination of two or more.

Examples of the conjugated diene used in the present invention include 1,3-butadiene, isoprene, 1,3-pentadiene and 2,3-dimethyl-
1,3-Butadiene and the like can be mentioned, but 1,3-butadiene and isoprene are preferable. These may be used alone or in combination of two or more.

Examples of the polymerization initiator used in the present invention include alkali metals such as lithium, sodium and potassium, and organic alkali metal compounds such as organic lithium compounds, organic sodium compounds and organic potassium compounds. Particularly preferred polymerization initiators include organic monolithium compounds, organic dilithium compounds, organic polylithium compounds, and the like, specifically, n-butyllithium, sec-butyllithium, ethyllithium, n-propyllithium, isopropyllithium. , N-decyl lithium, phenyl lithium, 2-naphthyl lithium, hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium, 1,2-dilithio-1,
Examples include 2-diphenylmethane and 1,3,5-trilithiobenzene. These are used alone or in a mixture of two or more.

In addition, as the organic polylithium compound used in the present invention, there can be used one that can substantially become an organic polylithium compound by reacting the above organic monolithium compound with another compound. For example, a reaction product of an organic monolithium compound and a polyvinyl aromatic compound (Japanese Patent Publication No. 55-6652), an organic monolithium compound and a conjugated diene, and / or a monovinyl aromatic compound are reacted with each other, and then the polyvinyl aromatic compound is reacted. Or a reaction product obtained by simultaneously reacting an organic monolithium compound, a conjugated diene, and / or a monovinyl aromatic compound, and a polyvinyl compound (West German Patent 2003384, etc.).

As the inert hydrocarbon solvent, cyclohexane, n-hexane, benzene are preferably used, but butane,
Aliphatic hydrocarbons such as pentane, heptane and octane, alicyclic hydrocarbons such as cyclopentane and methylcyclohexane, and aromatic hydrocarbons such as toluene and xylene can be used. Further, in producing the block copolymer, a small amount of a polar compound such as an ether or a tertiary amine may coexist in an inert solvent for the purpose of adjusting the microstructure of the conjugated diene portion.

The specific sulfur-containing compound or phosphorus-containing compound used in the present invention includes i) a sulfonic acid derivative having at least one SO ₂ bond in the molecule or sulfone ii) a sulfinic acid derivative having at least one SO bond in the molecule Or a sulfoxide iii) a sulfur-containing compound or a phosphorus-containing compound selected from the group consisting of thioethers or cyclic sulfides having at least one S bond in the molecule iv) phosphoric acid derivative v) phosphorous acid derivative, sulfonic acid, sulfinic acid , Phosphoric acid, halides of phosphorous acid, derivatives such as esters and amideimides, and sulfones, sulfoxides, thioethers, and cyclic sulfides. Of these, preferred are sulfonic acid derivatives.

The following compounds may be mentioned as specific examples.

Examples of the sulfonic acid derivative include sulfuryl chloride, sulfuryl bromide, methanesulfonic acid chloride, methanesulfonic acid bromide, ethanesulfonic acid chloride, ethanesulfonic acid bromide, benzenesulfonic acid chloride, benzenesulfonic acid bromide, and p-toluenesulfone. Acid chloride, p-toluene sulfonate bromide, methyl methane sulfonate, ethyl methane sulfonate, phenyl methane sulfonate, methyl benzene sulfonate, ethyl benzene sulfonate, phenyl benzene sulfonate, methyl p-toluene sulfonate, p- Ethyl toluenesulfonate, phenyl p-toluenesulfonate, 1,3-propanesultone, 1,4-butanesultone, naphthalsultone, methanesulfonamide, N, N-dimethylmethanesulfonamide, benzenesulfonamide, N, N-dimethylbenzene Sulfonamide p-toluenesulfonamide, N, N-dimethyl-p-toluenesulfonamide, N-phenyl-N-methyl-p-toluenesulfonamide, dibenzenesulfonimide, N-methyldibenzenesulfonimide, dimethanesulfonimide, Examples include N-methyldimethanesulfonimide, sulfur dioxide, and sulfur trioxide.

Examples of the sulfone include dimethyl sulfone, diethyl sulfone, diphenyl sulfone and di-p-methylphenyl sulfone.

Examples of the sulfinic acid derivative include thionyl chloride, thionyl bromide, methanesulfinic acid chloride, methanesulfinic acid bromide, ethanesulfinic acid chloride, ethanesulfinic acid bromide, benzenesulfinic acid chloride, benzenesulfinic acid bromide, and p-toluenesulfinic acid. Acid chloride, p-toluenesulfinic acid bromide, methyl methanesulfinate, ethyl methanesulfinate, phenyl methanesulfinate, methyl benzenesulfinate, ethyl benzenesulfinate, phenyl benzenesulfinate, ethyl p-toluenesulfinate, p- Toluenesulfinic acid phenyl, methanesulfinamide, N, N-dimethylmethanesulfinamide, benzenesulfinamide, N, N-dimethylbenzenesulfinamide, p-toluenesulfinamide, N, N-dimethyl-p- There are toluenesulfinamide, N-phenyl-methyl-p-toluenesulfinamide, dibenzenesulfinimide, N-methyldibenzenesulfinimide, dimethanesulfinimide, N-methyldimethanesulfinimide and the like.

Examples of the sulfoxide include dimethyl sulfoxide, diethyl sulfoxide, di-n-propyl sulfoxide, ethylmethyl sulfoxide, diphenyl sulfoxide, methylphenyl sulfoxide, di-p-methylphenyl sulfoxide and the like.

Examples of thioethers and cyclic sulfides include dimethyl thioether, diethyl thioether, diphenyl thioether, ethylene sulfide, propylene sulfide, 1,2-butene sulfide, isobutylene sulfide, cyclohexene sulfide, styrene sulfide, thietane, 2-methylthietane, 3,3-dimethylthiene. There are tongue and so on.

Examples of phosphoric acid derivatives and phosphorous acid derivatives include phosphorus oxychloride, trimethyl phosphate, triethyl phosphate, other trialkyl phosphates, triaryl phosphate, phosphorus chloride, trimethyl phosphite, triethyl phosphite, and other Examples include trialkyl phosphates, triaryl phosphites, and their corresponding sulfur-containing compounds.

The terminal-modified block copolymer obtained by the above method preferably has residues of the sulfur-containing compound or the phosphorus-containing compound bonded to all the polymer chain terminals, but a polymerization initiator, a sulfur-containing compound Depending on the type of compound or phosphorus-containing compound, reaction conditions, etc., the proportion of residues bonded may change, or a coupling reaction may partially occur. However, in order to achieve the object of the present invention, it is necessary that the proportion of the polymer in which the residue is bonded to the terminal in the whole polymer is 10% by weight or more, preferably 20% by weight or more. And particularly preferably 30% by weight or more. If it is less than 10% by weight, the desired effect of improving the physical properties cannot be obtained.

The amount of the sulfur-containing compound or the phosphorus-containing compound used in the present invention is 0.01 mol to 10 mol per 1 mol of the alkali metal in the polymerization initiator used when polymerizing the block copolymer.
It is a mole, and preferably 0.2 to 3 moles.

In the present invention, when a block copolymer having an alkali metal atom bonded to at least one polymer chain end is reacted with a specific sulfur-containing compound or phosphorus-containing compound to obtain an end-modified block copolymer, the polymer is It is preferable that the chain end has a structure in which an alkali metal atom is bonded to a conjugated diene unit because the ratio of the residue of the sulfur-containing compound or the phosphorus-containing compound bonded becomes higher and the effect of improving the physical properties becomes greater.

In addition, in some cases, the obtained terminal-modified block copolymer may be further substituted with hydrogen for the alkali metal portion with alcohol, water, mineral acid, carboxylic acid, or the like.

After completion of the reaction, the block copolymer having the terminal modifier residue bound thereto is recovered from the reaction solution by using a conventional separation method such as addition of a coagulant such as methanol, stripping with steam, and use of a heat roll. It

The process oil that constitutes the composition of the present invention is a process oil obtained by highly refining a petroleum fractionated product by a method well known in the art such as solvent reforming and hydroreforming, and has a viscosity specific gravity constant. It is less than 0.900.

Here, the viscosity specific gravity constant (Viscosity Gravity Constant, hereinafter abbreviated as VGC) is However, the specific gravity of oil at G = 60 ° F is given by the viscosity (SUS) of oil at V ₁ = 210 ° F.

Normally, process oil is classified into each type according to its component, but if VGC is used, VGC is 0.790 to 0.819.
Those of paraffin type, those of 0.820 to 0.849 are quite paraffin type, those of 0.850 to 0.899 are naphthene type, 0.900
-0.949 is quite aromatic, 0.950-0.999 is aromatic, 1.000-1.049 is extremely aromatic, 1.
Those above 050 are classified as extreme aromatic.

The process oil used in the present invention is VGC
Selected from all process oils below 0.900. When VGC is larger than 0.900, the aromatic component is rich and the tensile strength is remarkably lowered, which is not preferable. A more preferable VGC range is 0.820 to 0.900.

The amount of the process oil added is 10 to 200 parts by weight, preferably 20 to 150 parts by weight, based on 100 parts by weight of the block copolymer. If the addition amount is less than 10 parts by weight, the effect of improving the fluidity, which is the original purpose of blending the process oil, is not sufficient, and if it exceeds 200 parts by weight, the tensile strength is remarkably lowered, which is not preferable.

As the inorganic filler constituting the composition of the present invention, heavy or light calcium carbonate, magnesium carbonate, barium carbonate, silica, aluminum hydroxide, magnesium oxide,
Titanium dioxide, silicate, clay, etc. Each can be used alone or in combination of two or more. For application to the composition of the present invention, calcium carbonate and titanium dioxide are preferred. Use 1 per 100 parts by weight of block copolymer
It may be in the range of 0 to 150 parts by weight, preferably 10 to 100 parts by weight. If the amount added is less than 10 parts by weight, the oil absorbency and rigidity are not substantially improved, and if it exceeds 150 parts by weight, the tensile strength and fluidity of the composition are impaired, which is not preferable.

The composition of the present invention may contain a polystyrene resin as required. Polystyrene resin is a resin containing 80% by weight or more of styrene or a styrene derivative,
Generally, there are resins called general-purpose polystyrene, high-impact polystyrene, poly-α-methylstyrene, and poly-p-methylstyrene. In the present invention, polystyrene is preferably used. These may be used alone or in combination of two or more, but the total amount thereof is 0 to 120 parts by weight with respect to 100 parts by weight of the block copolymer,
It is preferably in the range of 10 to 90 parts by weight. If the compounding amount exceeds 120 parts by weight, the rubber elasticity of the composition is significantly lowered, which is not preferable.

The thermoplastic elastomer composition for footwear of the present invention contains the above-mentioned components (a), (b) and (c) as essential components,
If necessary, it contains the component (d), but in addition, if necessary, an antioxidant, an ultraviolet absorber, an antistatic agent, a flame retardant,
Fillers, reinforcing agents, foaming agents, colorants, lubricants, pigments and the like can be included.

The composition of the present invention can be obtained by mixing the respective components with a kneader such as a roll, Banbury mixer, kneader or extruder.
Appropriate temperatures for kneading are 130 to 170 ° C for rolls, 130 to 180 ° C for Banbury mixers, and 150 to 200 ° C for extruders. These can also be pelletized using a sheet pelletizer, crusher, or extruder.

The composition thus obtained is flexible and excellent in rubber elasticity, and has tensile strength, elongation, impact resilience, and elasticity without impairing fluidity.
Since it has improved wear resistance, oil resistance, and flex resistance, it can be used as a footwear material such as a unit sole, a direct sole, a foam direct sole, and foam sandals.

[Examples] Examples 1 to 11 and Comparative Examples 1 to 3 A stainless steel reactor having an internal volume of 10 was washed, dried, and sufficiently replaced with dry nitrogen, and then cyclohexane 5500 g,
Charge 190 g of styrene and 1.5 g of tetrahydrofuran, and heat the temperature of the contents so that the temperature of the contents becomes 70 ° C while stirring the contents, and stop heating as soon as the temperature reaches 70 ° C. N-Butyllithium (cyclohexane solution) 15 mmol Was added to start the polymerization of styrene. After 15 minutes, when the styrene monomer was almost completely consumed, 590 g of 1,3-butadiene was added.
Thirty minutes after the polymerization of 1,3-butadiene was completed, 190 g of styrene was added again. After 15 minutes, when the styrene monomer was almost completely consumed, 30 g of 1,3-butadiene was added again, and 1,3-butadiene was almost completely consumed in 10 minutes. After the completion of the polymerization reaction, 30 mmol of the compound shown in Table 2 was added, stirred for 20 minutes, added with 5 g of water, and further stirred for 5 minutes.

In Comparative Example 1, 5 g of water was added after completion of the polymerization reaction, and
Stir for minutes. Further, in Comparative Example 2, water was added after the polymerization reaction was completed.
After adding 5 g and stirring for 5 minutes, 1,3-propane sultone 30
Mmol was added. In Comparative Example 3, after the completion of the polymerization reaction, 15 mmol of ethylene oxide was added and stirred for 20 minutes, then 5 g of water was added and further stirred for 5 minutes.

The polymer solution thus obtained was taken out of the reactor,
Block copolymer of 6-di-tert-butyl-4-methylphenol and tris (nonylphenyl) phosphite
0.5 part by weight of each was added to 100 parts by weight and dried on a hot roll to obtain a polymer.

The polymer thus obtained was kneaded on a roll according to the formulation A shown in Table 1 to obtain a formulation.

The total styrene content in the obtained block copolymer and the measurement results of physical properties of the compound obtained by compounding with compounding formulation A are shown in Table-
2 shows.

Note 4) Measured using an ultraviolet spectrophotometer (Hitachi UV-200).

Note 5) The measurement was performed according to the following method.

Melt flow index ASTM D1238 E condition Dunlop impact resilience (25 ° C) BS 903 Wear resistance Akron wear (index) Demarsha bending JIS K-6301 Tensile test JIS K-6301 Note 6) Oil resistance test is JIS 3 with 2mm thickness Using a No. dumbbell as a test piece, immerse the test piece in JIS No. 3 oil and apply 50 at 25 ° C.
After holding for a time, the rate of weight increase was measured and a tensile test was conducted.

The physical property retention rate and the weight increase rate were calculated by the following formulas.

From the results of Table-2, the composition containing the terminal-modified block polymer of the present invention shows that tensile strength,
It can be seen that the elongation, impact resilience, wear resistance, oil resistance, and flex resistance are remarkably improved.

Examples 12 to 22 and Comparative Examples 4 to 6 In the same manner as in Examples 1 to 11, cyclohexane (5500 g), styrene (140 g) and tetrahydrofuran (1.5 g) were charged into a reactor and the temperature was raised to 70 ° C. with stirring, and n-butyllithium was added. 20 mmol was added to initiate the polymerization of styrene. After 15 minutes, when styrene monomer was almost completely consumed, 720 g of 1,3-butadiene was added, and after 40 minutes, 1,3-butadiene was almost completely consumed, 140 g of styrene was added, and then 15 minutes The styrene monomer was almost completely consumed later. After the completion of the polymerization, 40 mmol of the compound shown in Table 3 was added and the stirring was continued for 20 minutes, then 5 g of methanol was added and the stirring was continued for further 5 minutes. However, in Comparative Examples 4 and 5, after completion of the polymerization, 5 g of methanol was added and stirred for 5 minutes. In Comparative Example 5, 40 mmol of methanesulfonic acid chloride was further added thereafter.

Further, in Comparative Example 6, in the same manner as in Examples 1 to 11, cyclohexane 5500 g, styrene 280 g, tetrahydrofuran 1.5
g was charged into a reactor and the temperature was raised to 70 ° C. with stirring, and 40 mmol of n-butyllithium was added to start polymerization of styrene. After 15 minutes, when the styrene monomer was almost completely consumed, 720 g of 1,3-butadiene was added, and after 30 minutes, the 1,3-butadiene was almost completely consumed. The temperature was raised to 70 ° C., 60 mmol of m-divinylbenzene was added, and stirring was continued for 8 hours while maintaining the temperature at 70 ° C. 8 hours later
After adding 80 mmol of methanesulfonic acid chloride and stirring for 20 minutes, 5 g of methanol was added and stirring was continued for further 5 minutes.

The polymer was recovered in the same manner as in Examples 1 to 11 and kneaded on a roll according to the compounding formulation B in Table 1 to obtain a compounding.

Table 3 shows the total styrene content in the block copolymer measured in the same manner as in Examples 1 to 11 and the results of measuring the physical properties of the blends.

Also from the results of Table-3, the composition containing the terminal-modified block copolymer of the present invention shows tensile strength, elongation, impact resilience, abrasion resistance, oil resistance, and flex resistance without lowering the fluidity. It can be seen that it is a significantly improved composition.

[Advantages of the Invention] The thermoplastic elastomer composition for footwear of the present invention is flexible and has excellent rubber elasticity, and has tensile strength, elongation, impact resilience, abrasion resistance, oil resistance, and flex resistance without impairing fluidity. Since it is improved, it can be used as a footwear material such as a unit sole, a direct sole, a foam direct sole, and foam sandals.

Claims (1)

[Claims] 1. A block copolymer comprising: (a) a polymer block mainly containing at least two vinyl aromatic compounds and a polymer block mainly containing at least one conjugated diene, A block copolymer having an alkali metal atom bonded to the end of the polymer chain, i) a sulfonic acid derivative having at least one SO ₂ bond in the molecule or sulfone ii) a sulfinic acid derivative having at least one SO bond in the molecule, or Sulfoxide iii) Thioether or cyclic sulfide having at least one S bond in the molecule iv) Phosphoric acid derivative v) Phosphorous acid derivative Terminal modification obtained by reaction with a sulfur-containing compound or phosphorus-containing compound selected from the group consisting of 100 parts by weight of a thermoplastic elastomer which is a block copolymer, and (b) a process oil having a viscosity specific gravity constant of 0.900 or less. 1
A thermoplastic elastomer composition for footwear, which comprises 0 to 200 parts by weight, (c) 10 to 150 parts by weight of an inorganic filler, and (d) 0 to 120 parts by weight of a polystyrene resin.