Process for producing thermoplastic elastomer, and thermoplastic elastomer

Patent metadata

Field	Value
Publication number	US-10472452-B2
Application number	US-201715820842-A
Country	US
Kind code	B2
Filing date	Nov 22, 2017
Priority date	May 26, 2015
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A method for producing a thermoplastic elastomer includes forming a first block by copolymerizing a C4-C7 isoolefin monomer and alkylstyrene in the presence of a polymerization initiator; and forming a second block by polymerizing aromatic vinyl monomers. The thermoplastic elastomer comprises the first block and the second block. An amount of unreacted portion of the alkylstyrene during the formation of the first block is maintained at a molar ratio of not more than 1/90 relative to a total amount of the isoolefin monomer. The alkylstyrene is represented by the general formula (1), and the polymerization initiator is represented by the general formula (2).

First claim

What is claimed is:

1. A method for producing a thermoplastic elastomer, the method comprising:
forming a first block by copolymerizing a C4-C7 isoolefin monomer and alkylstyrene in the presence of a polymerization initiator; and
forming a second block by polymerizing aromatic vinyl monomers, wherein
the thermoplastic elastomer comprises the first block and the second block,
the formation of the first block comprises adding the alkylstyrene to a reaction solution containing the polymerization initiator and the C4-C7 isoolefin monomer by drip-feeding for not less than 10% of a total time of the formation of the first block,
the alkylstyrene is represented by the following general formula (1):

wherein R 1 and R 2 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a C1-C5 alkyl group, and a C1-C5 halogenated alkyl group,
the alkylstyrene is added such that an amount of unreacted alkylstyrene is maintained at a molar ratio of not more than 1/90 relative to a total amount of the isoolefin monomer during the formation of the first block, and
the polymerization initiator is represented by the following general formula (2):

wherein R 3 is each independently a hydrogen atom or a C1-C6 monovalent hydrocarbon group; R 4 is a monovalent or polyvalent aromatic hydrocarbon group, or a monovalent or polyvalent aliphatic hydrocarbon group; X is each independently a halogen atom, a C1-C6 alkoxyl group, or a C1-C6 acyloxy group; and n is an integer of 1 to 6.

2. The method according to claim 1 , wherein R 1 and R 2 are each independently a hydrogen atom or a C1-C5 alkyl group.

3. The method according to claim 1 , wherein a molar ratio of the alkylstyrene to the polymerization initiator is 1:1 to 100:1.

4. The method according to claim 1 ,
wherein the thermoplastic elastomer has a triblock structure comprising the first block and the second block, and
wherein the first block is a block in the middle of the triblock structure and the second block is a block at both ends of the triblock structure.

5. The method according to claim 1 , wherein the C4-C7 isoolefin monomer is isobutylene.

6. The method according to claim 1 , wherein the alkylstyrene is p-methyl styrene, and the aromatic vinyl monomer is styrene.

7. The method according to claim 1 , wherein the first block comprises a unit derived from the C4-C7 isoolefin monomer and a unit derived from the alkylstyrene that are randomly connected.

8. The method according to claim 1 ,
wherein the thermoplastic elastomer is a block-structured polymer comprising the first block and the second block, and
wherein the block-structured polymer has a weight average molecular weight of 5,000 to 1,000,000.

9. The method according to claim 1 ,
wherein the thermoplastic elastomer is a block-structured polymer comprising the first block and the second block, and
wherein a weight average molecular weight of the first block accounts for 60% to 95% of a weight average molecular weight of the block-structured polymer.

10. The method according to claim 1 , wherein the first block has a molecular weight distribution of not more than 1.7.

11. The method according to claim 1 , further comprising introducing a halogen group into the thermoplastic elastomer.

12. The method according to claim 11 , further comprising introducing a functional group other than the halogen group by reacting the halogen group of the thermoplastic elastomer with a functionalizing agent.

13. The method according to claim 2 , wherein a molar ratio of the alkylstyrene to the polymerization initiator is 1:1 to 100:1.

14. The method according to claim 2 ,
wherein the thermoplastic elastomer has a triblock structure comprising the first block and the second block, and
wherein the first block is a block in the middle of the triblock structure and the second block is a block at both ends of the triblock structure.

15. The method according to claim 3 ,
wherein the thermoplastic elastomer has a triblock structure comprising the first block and the second block, and
wherein the first block is a block in the middle of the triblock structure and the second block is a block at both ends of the triblock structure.

16. The method according to claim 2 , wherein the C4-C7 isoolefin monomer is isobutylene.

17. The method according to claim 3 , wherein the C4-C7 isoolefin monomer is isobutylene.

Assignees

• Kaneka Corp
• Michelin & Cie

Inventors

• Kato Yasunaka
• Ikari Yoshihiro

Classifications

• C08F297/00

  Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer · CPC title

• C08F2810/30

  leading to the formation or introduction of aliphatic or alicyclic unsaturated groups · CPC title

• C08F8/22 Primary

  by reaction with free halogens · CPC title

• C08F297/06

  using a catalyst of the coordination type · CPC title

• C08F2810/50

  wherein the polymer is a copolymer and the modification is taking place only on one or more of the monomers present in minority · CPC title