JPH0742391B2 - Thermoplastic elastic composition for footwear - 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, it consists of 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 terminal-modified block copolymer obtained by reacting a specific nitrogen-containing compound. The present invention relates to a thermoplastic elastic body composition for footwear, which has improved tensile strength, elongation, impact resilience, wear 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 and TR) is an excellent thermoplastic elastic body without 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, the SB type TR type is remarkably inferior in fluidity to ordinary thermoplastic resins, and moreover, it is apt to undergo thermal deterioration at high temperatures, and therefore it is difficult to raise the processing temperature during molding to improve the 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, the hardness of SB-based TR is improved by using a specific composition of 1,2-polybutadiene or the like.
Although it is disclosed that the composition has excellent fluidity, appearance of molded article, flex resistance, and ozone resistance, its improvement effect is insufficient, and the impact resilience, oil resistance, and abrasion resistance are improved. The effect is not disclosed. In JP-A-59-223744, the SB system is used.
Although it is disclosed that the oil resistance can be improved by blending an acrylic copolymer with TR, 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] The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, surprisingly, an alkali metal atom was bonded to the polymer chain terminal. It was 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 nitrogen-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 end, and i) in the molecule And a compound having at least one N—R ₁ group respectively (wherein X represents an oxygen atom, R ₁ represents hydrogen or a carbon number of 1 to 20).
Represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, and an alkenyl group), amide, lactam, imide, urea compound, carbamate, amino-substituted benzophenone.

ii) A compound having at least one -N = C = X group in the molecule (wherein X represents an oxygen atom or a sulfur atom).

100 parts by weight of a thermoplastic elastomer, which is a terminal-modified block copolymer obtained by reacting with a nitrogen-containing compound selected from the group consisting of: and (b) a process oil 1 having a viscosity specific gravity constant of 0.900 or less.
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 nitrogen-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 a polymer chain end and a specific nitrogen-containing compound is a polymer obtained by modification. Since the residue of the nitrogen-containing compound bonded to the chain end has a polar portion, the affinity for the surface of the inorganic filler when compounded with the inorganic filler becomes strong and the residue of the nitrogen-containing compound is not bonded to the block. The tensile strength, impact resilience, etc. are improved as compared with the composition using the polymer. However, at high temperatures, this action is weakened by thermal motion, and fluidity during molding and processing is not impaired.

In addition, the effect of the residue of the nitrogen-containing compound being bonded to the end of the block copolymer chain is that the tensile strength, elongation, oil resistance, and impact resilience are greater than when bonded to the center of the polymer chain. , Is excellent in bending resistance.

These are achieved only by attaching a residue of a specific nitrogen-containing compound to the polymer chain end.

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 vinyl aromatic compound, for example, JP-B-36-19286. JP-B, JP-B-48-2423, JP-B-48-4106, JP-B-49-36957 and the like, the method described in, for example, in an inert hydrocarbon solvent, as an anionic polymerization initiator This is a method of block-copolymerizing a conjugated diene and a vinyl aromatic compound using an organic lithium compound or the like.

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-B _n R (wherein A is a polymer block containing a vinyl aromatic compound as a main component, and B is a polymer block containing a conjugated diene as a main component). Coalescing block,
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 remarkably lowered, which is not preferable.

Further, the polymerization 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
Chem., 21 , 943 (1943)).

Examples of the vinyl aromatic compound used in the present invention include styrene, p-methylstyrene, α-methylstyrene, p
Examples include -tert-butylstyrene, but styrene and p-methylstyrene are 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, 2,3-dimethyl-1,3-butadiene, and the like, with 1,3-butadiene and isoprene being preferred. . 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 are 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-
Examples include naphthyl lithium, hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium, 1,2-dilithio-1,2-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 Examined Patent Publication No. 55-6652), an organic monolithium compound and a conjugated diene, and / or a monovinyl aromatic compound are reacted, and then a 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 and benzene are preferably used, but in addition, aliphatic hydrocarbons such as butane, pentene, 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 nitrogen-containing compound used in the present invention includes i) And a compound having at least one N—R ₁ group respectively (wherein X represents an oxygen atom, R ₁ represents hydrogen or a carbon number of 1 to 20).
Represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, and an alkenyl group), amide, lactam, imide, urea compound, carbamate, amino-substituted benzophenone.

ii) A compound having at least one -N = C = X group in the molecule (wherein X represents an oxygen atom or a sulfur atom).

It is a nitrogen-containing compound selected from the group consisting of:

The following compounds may be mentioned as specific examples.

As the amide, foramide, acetamide, propioamide, benzamide, methacrylamide, 2-pyridylamide, 4-pyridylamide, nicotinamide, acrylamide, N, N-dimethyl-p-aminobenzamide, p-aminobenzamide, N, N- Dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-dimethylacetamide, N, N-dimethylpropioamide, N, N-diethylpropioamide, N, N-
Dimethylbenzamide, N, N-diethylbenzamide,
N, N-dimethyl-2-pyridylamide, N, N-dimethyl-
4-pyridylamide, N, N-diethyl-4-pyridylamide, N, N-dimethylnicotinamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N, N-dimethylmethacrylamide, N, N- Diethylmethacrylamide, N-phenylformamide, N-phenylacetamide, N-phenylpropioamide, N-methyl-N
-Phenylacetamide, N, N-dimethyl (N ', N'-
p-dimethylamino) benzamide, N, N-diethyl (N ', N'-p-dimethylamino) benzamide, N, N
-Dimethyl (N ', N'-p-diethylamino) benzamide, N, N-diethyl (N', N'-p-diethylamino) benzamide, and the like.

As the lactam, ε-caprolactam, N-methyl-
ε-caprolactam, δ-valerolactam, N-methyl-δ-valerolactam, 2-pyrrolidone, N-methyl-
2-pyrrolidone, N-acetyl-ε-caprolactam and the like.

Examples of the imide include succinimide, N-methylsuccinimide, N-phenylsuccinimide, maleimide, N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, phthalimide, N-methylphthalimide and N-phenylphthalimide.

As the urea compound, urea, N, N′-dimethylurea, N,
N'-diethylurea, N, N'-diphenylurea, N, N, N ',
N'-tetramethylurea, N, N, N ', N'-tetraethylurea, N, N-dimethyl-N', N'-diethylurea, N, N-dimethyl-N ', N'-diphenylurea, N, N'-Dimethylethyleneurea, N, N'-Diethylethyleneurea, N, N'-
Dipropyl ethylene urea, N-ethyl-N'-methyl ethylene urea, N-methyl-N'-phenyl ethylene urea, N-ethyl-N'-phenyl ethylene urea, N, N '
-Diphenylethylene urea, N, N'-dimethyl propylene urea, N, N'-diethyl propylene urea, N, N ', N "-
Trimethyl isocyanuric acid and the like.

As the carbamic acid ester, methyl carbamate,
Methyl N, N-dimethylcarbamate, Methyl N, N-diethylcarbamate, ethyl carbamate, ethyl N, N-dimethylcarbamate, ethyl N, N-diethylcarbamate, phenyl carbamate, N, N-dimethylcarbamine Phenyl acid, phenyl N, N-diethylcarbamate and the like.

In addition to the above amides, lactams, imides, urea compounds and carbamic acid esters, C═O groups and N—R ₁ groups (R ₁ is hydrogen or an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, Which represents a substituent selected from alkenyl groups) in the same molecule,
Amino-substituted benzophenones, specific examples of which are p-dimethylaminobenzophenone, p-diethylaminobenzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 4,4'-diaminobenzophenone and so on.

As the isocyanate compound, methyl isocyanate, ethyl isocyanate, propyl isocyanate,
η-butyl isocyanate, cyclohexyl isocyanate, η-hexyl isocyanate, allyl isocyanate, phenyl isocyanate, naphthyl isocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate,
Naphthylene-1,5-diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate hydroxide,
Hydrogenated-4,4'-diphenylmethane diisocyanate,
Examples include isophorone diisocyanate, lysine diisocyanate, and isopropylidene bis (4-cyclohexyl isocyanate).

Moreover, the compound which substituted the oxygen atom in these said compounds by the sulfur atom is mentioned.

The terminal-modified block copolymer of the present invention, which is obtained by reacting the polymer chain end with the compound i) or ii). Specifically, the polymer chain end is modified by the compound i). (In the case of amino-substituted benzophenone Becomes The modification with compound ii) is due to a carbamoylation reaction, and the polymer chain ends are Becomes

The terminal-modified block copolymer obtained by the above method preferably has residues of the nitrogen-containing compound bound to all polymer chain terminals, but the polymerization initiator, the type of the nitrogen-containing compound, and the reaction Depending on the conditions, etc., the ratio of residues bonded may change, or the 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
It is more than weight%. If it is less than 10% by weight, the desired effect of improving the physical properties cannot be obtained.

The amount of the nitrogen-containing compound used in the present invention is 0.01 mol to 10 mol, preferably 0.2 to 2 mol, based on 1 mol of the alkali metal in the polymerization initiator used when polymerizing the block copolymer. Is.

In order to obtain a terminal-modified block copolymer 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 nitrogen-containing compound, the polymer chain end is conjugated. A structure in which an alkali metal atom is bonded to a diene unit is preferable because the ratio of the residue of the sulfur-containing compound bonded is increased and the effect of improving the physical properties is increased.

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 constituting 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-based 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 blending amount exceeds 120 parts by weight, the rubber elasticity of the composition is significantly reduced, 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, and extruder with a mixer. The kneading temperature is 130-170 for rolls.
℃, 130-180 ℃ for Banbury mixer, 15 for extruder
0 to 200 ° C is suitable. These are sheet pelletizers,
Pelletization is also possible using a 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 5000 g,
200 g of styrene and 1.25 g of tetrahydrofuran were charged, and the contents were stirred and heated so that the temperature of the contents became 70 ° C. When the contents reached 70 ° C, the heating was stopped and n-butyllithium (cyclohexane solution) 15 mmol was added. Was added to start the polymerization of styrene. After 15 minutes, when the styrene monomer was almost completely consumed, 570 g of 1,3-butadiene was added. 30 minutes after the polymerization of 1,3-butadiene was completed, the
00g of styrene was added. After 15 minutes, when the styrene monomer was almost completely consumed, another 30 g of 1,3-
1,3-Butadiene was almost completely consumed in 10 minutes after the addition of butadiene. After the completion of the polymerization reaction, the compounds shown in Table 2 were added in an amount of 15 mmol, stirred for 20 minutes, added with 5 g of methanol, and further stirred for 5 minutes.

In Comparative Example 1, 5 g of methanol was added after completion of the polymerization reaction, and the mixture was stirred for 5 minutes. Further, in Comparative Example 2, after completion of the polymerization reaction, 5 g of methanol was added and stirred for 5 minutes, and then N, N-
Dimethylacetamide 15 mmol was added. Comparative Example 3
Then, after the completion of the polymerization reaction, add 15 mmol of ethylene oxide.
After stirring for 20 minutes, 5 g of methanol was added and stirring was continued for another 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.

* 1) Diana Process NS-100 manufactured by Idemitsu Kosan * 2) Shiroishi Kogyo Akadama Mark Light Calcium Carbonate * 3) Asahi Kasei Styron 679 Obtained by compounding with the total styrene content and formulation A of the block copolymer obtained. Table 2 shows the results of measuring the physical properties of the prepared blends.
Shown in.

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 ℃) BS903 Wear resistance Akron wear (index) Demarsha bending JIS K−6301 Tensile test JIS K−6301 Note 6) Oil resistance test is JIS No. 3 with 2mm thickness A dumbbell was used as a test piece, and the test piece was immersed in JIS No. 3 oil and held at 25 ° C. for 50 hours, then the weight increase rate was measured, and a tensile test was performed.

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 5000 g, styrene 150 g, and tetrahydrofuran 1.5 g were charged into a reactor, and the temperature was raised to 70 ° C. with stirring, and n-butyl lithium was added. 20
The mmol was added to initiate the polymerization of styrene. After 15 minutes, when the styrene monomer was almost completely consumed, 700 g of 1,3-butadiene was added, and after 40 minutes, when 1,3-butadiene was almost completely consumed, 150 g of styrene was added, and then 15 minutes was added. The styrene monomer was almost completely consumed later. After the completion of the polymerization, 20 mmol of the compound shown in Table 3 was added, stirring was continued for 20 minutes, 5 g of methanol was added, and the stirring was further continued for 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, 20 mmol of N-methyl-ε-caprolactam was further added thereafter.

Further, in Comparative Example 6, in the same manner as in Examples 1 to 11, cyclohexane 5000 g, styrene 300 g, tetrahydrofuran 1.5
After charging g to a reactor, 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, 700 g of 1,3-butadiene was added, and after 30 minutes, 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. After 8 hours, 40 mmol of N, N-dimethylformamide was added and stirred for 20 minutes, and then 5 g of methanol was added to further add 5
Stirring was continued for a minute.

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 the composition 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, and i) in the molecule And a compound having at least one N—R ₁ group respectively (wherein X represents an oxygen atom, R ₁ represents hydrogen or a carbon number of 1 to 20).
Represents a substituent selected from an alkyl group, a cycloalkyl group, an aryl group, and an alkenyl group), amide, lactam, imide, urea compound, carbamate, amino-substituted benzophenone. ii) A compound having at least one -N = C = X group in the molecule (wherein X represents an oxygen atom or a sulfur atom). 100 parts by weight of a thermoplastic elastomer, which is a terminal-modified block copolymer obtained by reacting with a nitrogen-containing compound selected from the group consisting of: and (b) a process oil 1 having a viscosity specific gravity constant of 0.900 or less.
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.