JPS59166518A - Straight-chain block copolymer - Google Patents

Abstract

PURPOSE:To obtain the titled copolymer having balanced tensile strength and elongation, composed of a block of a vinyl aromatic compound and a block composed mainly of a conjugated diene and containing a vinyl aromatic compound in a particular form, and obtained by the polymerization of the above monomers in hydrocarbons in the presence of an organic Li compound. CONSTITUTION:A block copolymer of formula A-B-A (A is block of vinyl aromatic compound polymer and the total amount of A is 50-97wt% based on the whole vinyl aromatic compound; B is block of a copolymer composed mainly of a conjugated diene and containing a vinyl aromatic compound having 3-10 tapered blocks containing increasing amount of vinyl aromatic compound and having the weight ratio of the vinyl aromatic compound to the conjugated diene of 3-15/97-85) having a vinyl aromatic compound content of 25-55wt% and containing 5-30wt%, based on the whole vinyl aromatic compound, of the chain of the vinyl aromatic compound having 1-4 connected monomer units, is prepared by polymerizing a vinyl aromatic compound and a conjugated diene in a hydrocarbon solvent using an organic Li compound as a polymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel linear vinyl aromatic compound-conjugated diene block copolymer, and more particularly, to a novel linear vinyl aromatic compound-conjugated diene block copolymer having a non-elastomeric vinyl aromatic compound at both ends with balanced tensile strength and elongation. The invention relates to a linear block copolymer having an elastomeric copolymer block of a vinyl aromatic compound mainly composed of a conjugated diene and a conjugated diene in the center.

Recently, there has been an increasing demand for thermoplastic elastomers with a good balance of tensile strength and elongation in the field of polystyrene modification, both for aesthetic and practical reasons.

Linear block copolymers consisting of vinyl aromatic compounds and conjugated dienes are known in the technical field of anionic polymerization, such as Japanese Patent Publication No. 40-23798 and Japanese Patent Publication No. 46-3.
2415. However, the block copolymers obtained by these methods are still not fully satisfactory in terms of the balance between tensile strength and elongation.

Therefore, the present inventors conducted intensive studies to obtain a linear block copolymer with a good balance between tensile strength and elongation, and as a result, they arrived at the present invention. That is, the present invention provides a direct heir vinyl aromatic compound-conjugated diene block copolymer having a vinyl aromatic compound content of 25 to 55% by weight obtained by polymerizing an organolithium compound as an initiator in a hydrocarbon solvent. The union is the general formula A-B-A (the person in the formula is a vinyl aromatic compound polymer block, and the total amount of A at both ends is 50 to 50% of the entire vinyl aromatic compound).
97 weight ratio I3 is a copolymer with a vinyl aromatic compound mainly composed of a conjugated diene, and has 3 to 10 tapered blocks in which (al vinyl aromatic compound bleaches) ib) vinyl The aromatic compound/conjugated diene weight ratio is 3-15/97-85. ), and the amount of chains of 1 to 4 vinyl aromatic compounds in one monomer unit is 5% of the total vinyl aromatic compound content.
It is a linear block copolymer characterized by having a molecular weight of 30 to 30 parts.

The linear block copolymer of the present invention has a vinyl aromatic compound content of 25 to 55% by weight, and an inherited vinyl aromatic compound of 28 to 50% by weight. If the width is exceeded, the elongation will be poor.

The block copolymer of the present invention is characterized in that in the general formula A-B-A, 13 portions contain a vinyl aromatic compound in a specific range, and furthermore, it has a number of tapered blocks in a specific range, and the linear block copolymer also has a vinyl aromatic compound in a specific range. The polymer is a copolymer having a chain distribution of vinyl aromatic compounds within a specific range. Due to the characteristics of stiffness, the balance between tensile strength and elongation is excellent.
<Improved.

That is, the vinyl aromatic compound content of the B portion of the block copolymer of the present invention is 3 to 15% by weight, preferably 5 to 10% by weight.
It is hereditary in terms of weight, and the vinyl aromatic compound in part A is 50 to 97 of the total vinyl aromatic compounds, preferably 70 to 97.
This is Section 96.

3- If the content of the vinyl aromatic compound in the B part is less than 3 weights, the elongation will be poor, and if it exceeds 15 weights, the tensile strength will be poor. Furthermore, part B consists of tapered blocks in which the vinyl aromatic compound gradually increases, and the number of gooper blocks is 3 to 10.
number, preferably 3 to 7. If the number of gooper blocks is less than 3, the elongation will be poor, and if it exceeds 10, the tensile strength will be poor.

The chain distribution of vinyl aromatic compounds in linear block copolymers is such that the amount of chains of 1 to 4 vinyl aromatic compounds connected per monomer unit is 5 to 30 of the total vinyl aromatic compound content.
If the weight ratio is hereditary, or 15 to 30 weight ratios, and the hereditary chain is 4 or less, if it is less than 5 times hereditary, the elongation will be poor, and if the hereditary weight exceeds 30 weight, the tensile strength will be poor.

The block copolymer of the present invention can be produced by the following method.

That is, an ether or a tertiary amine is added to a hydrocarbon solvent, an organolithium compound is used as an initiator, and = 4- (1) a vinyl aromatic compound is added to 8 of the total amount of monomers used.
~40 weight section, hereditary or 10 to 25 weight section are hereditary,
After the polymerization reaction is substantially completed (2) Conjugated diene 85~
A mixture of 97% by weight and 3 to 15% by weight of a vinyl aromatic compound is polymerized in 3 to 10 times, and if necessary, an amount of butadiene equivalent to the amount added once is added and polymerized.

(3) Finally, a method can be used in which the vinyl aromatic compound is added in an amount of 8 to 40 parts by weight, or preferably 10 to 25 parts by weight, based on the total amount of monomer used.

In the above step of polymerizing the mixture of conjugated diene and vinyl aromatic compound in 3 to 10 times, it is preferable that the amount of monomer used each time is about the same, and in each step, approximately 1
It is desirable to carry out the polymerization at a rate of 0.00. Further, as a method of adding the monomer in 3 to 10 portions, a method of adding a monomer mixture, a method of adding a conjugated diene and a vinyl aromatic compound at the same time, etc. are used.

A copolymer of a vinyl aromatic compound and a conjugated diene having a preferable vinyl aromatic compound chain distribution can be obtained by polymerization by adding an ether or a tertiary amine to a hydrocarbon solvent. Addition of ether or tertiary amine increases the number of 1 to 4 chains in the vinyl aromatic compound, but if the number of chains exceeds 300 parts by weight of the vinyl aromatic compound content, the tensile strength will be poor.

From the viewpoint of controlling the chain distribution of the vinyl aromatic compound, the amount of ether or tertiary amine used is 0.000% per 100 parts by weight of monomer. (15 to 5 parts by weight is preferred, and more preferably 0.005 to 0.5 parts by weight.

Examples of the vinyl aromatic compound used in the present invention include styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, 0-methylstyrene, p-tert
-Methylstyrene, dimethylstyrene, vinylnaphthalene, etc. can be used.

Among these, styrene is preferable. However, as the conjugated diene, butadiene, isoprene, piperylene, etc. can be used. Among these, butadiene is preferred.

The weight average molecular weight of the linear block copolymer of the present invention is preferably 10.000 to 800.000, more preferably 50.000. (100 to 500.000. Of these, A
The weight average molecular weight of the part is 3,000-80.000, B
The weight average molecular weight of the portion is 44-. 000~340,00
0 is preferred.

The linear block copolymer of the present invention can be obtained by isothermal polymerization or adiabatic polymerization. The preferred polymerization humidity range is 3
The temperature is 0 to 120°C.

Examples of the hydrocarbon solvent used in producing the linear block copolymer of the present invention include cyclopenkune, cyclohexane, benzene, ethylbenzene, xylene, and mixtures thereof with pentane, hexane, heptane, butane, and the like.

Examples of organic lithium compounds include n-butyllithium, 5ec-butyllithium, and tert-butyllithium.
- Chilllithium, n-hexyl1)thium, sila-0-hexyllithium, phenyllithium, naphthyllithium, etc., in amounts of 0.04 to 1.0% per 100 parts of monomer.
Used at 0 parts by weight.

As the ether or tertiary amine, ether compounds such as tetrahydrofuran, diethyl ether, anisole, dimethoxybenzene, ethylene glycol dimethyl ether, triethylamine, N-dimethylaniline, pyridine, and tertiary amine compounds are used.

The linear block copolymer of the present invention is polystyrene,
2-Food containers and packaging by blending with polybutadiene, etc.
It can be used for toys, everyday miscellaneous goods, footwear, automobile parts, and electrical appliance parts if necessary.

In addition, the block copolymer of the present invention can be used in a wide range of areas, such as injection molded products such as footwear and containers, flow molded products such as toys and household goods, backings, sheets, and booleans. It can be suitably used for compression molded products such as. Since it dissolves in strong hydrocarbon solvents, it can also be effectively used as an adhesive. Furthermore, the block copolymer of the present invention is SB
It can also be mixed with other rubbers such as R and NBR, and plastics such as polystyrene to modify their physical properties.

For example, in rubber applications, it is used as a crepe-like sponge, and in plastic applications, it is used as an impact resistance improver for general-purpose polystyrene.

The present invention will be described in detail below with reference to examples, but the present invention is not limited unless it goes beyond the gist of the present invention.

In addition, various measurements were performed according to the following methods.

Tensile strength (TB) and elongation (EB) are JISK 630
Measured according to 1.

Transparency testing was based on ASTM-D-1003.

゛ The styrene chain was based on the method developed by Professor Otanaka et al. of Agriculture and Technology (Proceedings of the Society of Polymer Science and Technology, Vol. 29, No. 7, p. 2055).

The size and microstructure were determined by an infrared method (Morello method).

Total styrene content was determined by infrared method.

Example 1 Washing and drying 4.50% of cyclohexane ('lf
After adding 1 gram of tetrahydrofuran, the internal temperature was reduced to 70.
It was set to ℃.

Next, n-butyllithium 0.5! After adding the hexane solution containing i', 130 g of styrene was added and polymerized for 60 minutes. The polymerization conversion rate of styrene was 1%. Then, a mixture of styrene 157 and butadiene 1152 was added and polymerized for 60 minutes.

The polymerization conversion rate of styrene and butadiene was 100%. This operation was repeated two more times. Then add butadiene to 1
157 was added and polymerization was carried out at a polymerization conversion rate of 100. Thereafter, 1,307 ml of styrene was further added and polymerized for 60 minutes.

The conversion rate was 100.

During the polymerization, the temperature was always adjusted to 70°C. After the polymerization was completed, 2,6-sheet tcrt-butyl p-cresol was added to the polymer solution, and then cyclohexane was removed by heating to obtain a block copolymer.

Examples 2-8. Comparative Examples 1 to 1° Polymerization was carried out according to the same recipe as in Example 1 using predetermined amounts of styrene, butadiene, tetrahydrofuran, etc. as shown in Table 1.

(Left below) Examples 2 and 3: The bonded styrene of part B is 3 and 12, respectively.
4: An example where the number of monomer additions is 7 times. 5, 6: An example where fully bound styrene is 30% and 50%, respectively. 7: An example where paramethylstyrene is used instead of styrene. Comparative Examples 1 and 2: 20 and 60 qb of fully bound styrene, respectively
Nishida example〃3,4: Example in which the bound styrene of part B was 1-7 to 1st and 20th, respectively〃5,6: No addition of tetrahydrofuran and large excess (
6゜59/1009 monomer) Example 7, 8: The number of monomer additions for part B was 2 and 2, respectively.
Table 2 shows the properties of the block copolymer produced at 0 times.

(Left below) Examples 1 to 7 are superior to Comparative Examples 1 to 8 in terms of balance between tensile strength and elongation.

The diagram shows the styrene chain distribution curves of the copolymers of Example 1, Comparative Example 5, and Comparative Example 6 obtained by the oxidative decomposition method using ozone according to Tanaka's method.

The results were as shown in Table-3.

Table-3 Example 8. Comparative Example 9 A mixed composition of the block copolymer 12 of Example 1 and polystyrene (Topole Sox 525 manufactured by Mitsui Toatsu) was produced with a weight of 88% and a thickness of 0.2 at a molding temperature of 180°C.
We investigated the physical properties of Qi's sheet. For comparison, the physical properties of the polystyrene alone were investigated.

The results are shown in Table 4.

Table-4

[Brief explanation of the drawing]

The figure shows the copolymers of Example 1 and Comparative Examples 5 and 6.
The styrene chain distribution curve obtained by the oxidative decomposition method using ozone is shown. Patent Applicant: Japan Synthetic Rubber Co., Ltd. Agent Patent Attorney: Akira Ito Procedural Amendment (Voluntary) February 7, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1 Neutral Indication 1988 Patent Application No. 383/12 No. 2, Name of the invention: Straight-chain block copolymer, Relationship to the amended case Patent applicant address: 2-11-24 Tsukiji, Chuo-ku, Tokyo Name: Japan Synthetic Rubber Co., Ltd. Representative Yoshi Mitsuhisa 4, Agent 101 Address 5 Abe Building, 2-42 Kanda Jimbocho, Chiyoda-ku, Tokyo Subject of amendment 6 Contents of amendment (1) Scope of claims As attached (2) Detailed description of the invention Explanation ■. In the specification, page 5, lines 2 to 3, "If the weight is less than 15%, the elongation will be poor, and the tensile strength will be poor." has been corrected to ``If the weight is less than 15%, the tensile strength will be poor, and if it exceeds 15 weight, the elongation will be poor.'' do. 2. Delete "The microstructure was also determined." from the bottom line of page 10 to the first line of page 11. -2, Claims: “A vinyl aromatic compound obtained by polymerization using an organolithium compound as an initiator in a hydrocarbon solvent has a content of 25 to 5.
In the direct inheritance vinyl aromatic compound-conjugated diene block copolymer with a weight ratio of 5, the copolymer has the general formula (in the formula, the person is a vinyl aromatic compound polymer block, and the sum of the A's at both ends is a vinyl aromatic compound block copolymer. 50~ of all group compounds
97 weight division B is a copolymer with a vinyl aromatic compound mainly composed of a conjugated diene, and the B part has (a) 3 to 10 tapered blocks in which the vinyl aromatic compound gradually increases, (1)) The weight ratio of vinyl aromatic compound/conjugated diene is 3
~15/97~85. ), and the amount of chains of 1 to 4 vinyl aromatic compounds in one monomer unit is 5% of the total vinyl aromatic compound content.
A linear block copolymer characterized by a hereditary weight ratio of ~30. ” Procedural amendment (spontaneous) Kazuo Wakasugi, Commissioner of the Patent Office, Kogata λ3, 19801, Indication of case: Patent Application No. 88842, 19882, Title of invention: Linear block copolymer 8, Amendment Relationship with the case involving a person who does the following Patent applicant Address: 2-11-24 Tsukiji, Chuo-ku, Tokyo Name: Japan Synthetic Rubber Co., Ltd. Representative: Hisashi Yoshimitsu 4/Agent: 7. . 1 Address: 5 Abe Building, 2-1142 Kanda Jimbocho, Chiyoda-ku, Tokyo, Detailed explanation of the invention in the specification subject to amendment 6, Contents of amendment (1) “Additions” in lines 6 to 7 of page 6 of the specification Correct the statement that Bukuji has the same amount as outside to ``conjugated diene''. (2) Insert the following sentence between lines 9 and 10 on page 10. W Furthermore, the block copolymer of the present invention can be hydrogenated to improve heat resistance and weather resistance. Hydrogenated block copolymers can also be used for each of the above applications, and can also be blended with resins such as polystyrene and polyolefins and rubbers. (3) Styrene chain n of Comparative Example 6 in Table 2, page 15
= percentage value of 1-4) is "58" is "67"
” is corrected. (4) Before “4. Brief explanation of drawings” on page 17 of the same page,
Insert the following sentence. "Application Example: Dissolve 1000 g of the block copolymer of Example 1 in 5001 cyclohexane, add 13.9 g of tetrahydrofuran, and then add 100 ml of a cyclohexane solution containing 2.5 g of nickel acetylacetone and 40 g of triimbutylaluminum. 800 rnl
Add, 15Kq7crl, 10 ooc Nite60
The reaction was carried out for minutes. After the reaction was completed, the solution was washed several times with an aqueous hydrochloric acid solution, and then the same procedure as in Example 1 was carried out. The solvent was removed to obtain a polymer. Tensile strength of polymer 35
0 Kq/cy? r, elongation is 345, Izod impact strength is 8.2 and 9 crrL/cTL, Rockwell hardness is 4.
It was 6. ”

Claims (1)

[Scope of Claims] A linear vinyl aromatic compound-conjugated diene block copolymer containing 25 to 55% vinyl aromatic compound obtained by polymerization using an organolithium compound as an initiator in a hydrocarbon solvent. In the polymer, the copolymer has the general formula A-B-
A (In the formula, A is a vinyl aromatic compound polymer block, and the total amount of A at both ends is 50 to 50% of the entire vinyl aromatic compound.
97 weight division B is a copolymer with a vinyl aromatic compound mainly composed of a conjugated diene, and has 3 to 10 tapered blocks in which fat vinyl aromatic compound gradually increases, fb) vinyl aromatic The weight ratio of compound/conjugated diene is 3~
15797-85. ), characterized in that the chain of 1 to 4 vinyl aromatic compounds in one monomer unit is hereditary in an amount of 5 to 30 weight percent of the total vinyl aromatic compound content. Copolymer.