Thermoplastic elastomer composition

• US 5,436,295 A
• Filed: 01/07/1994
• Issued: 07/25/1995
• Est. Priority Date: 01/20/1993
• Status: Expired due to Term

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Hashimoto, Katsuya, Nishikawa, Makoto, Ishii, Masao
• Primary Examiner(s): Seidleck, James J.
• Assistant Examiner(s): Critharis, Mary
• Application Number:
  US08/178,653
• Time in Patent Office: 564 Days
• Field of Search: 525/125, 525/127, 525/130, 525/98, 525/92
• US Class Current: 525/92.00C
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 75/06 from polyesters

Abstract

A thermoplastic elastomer composition comprises the following two components:

(a) a thermoplastic polyurethane having soft segments from a poly (3-methyl-1,5-pentane adipate) diol having a molecular weight of at least 2,000 and having a JIS A hardness at 25° C. of not more than 80, and

(b) a block copolymer comprising at least 2 polymer blocks A principally comprising an aromatic vinyl compound and at least 1 block B comprising an olefinic elastomer, said aromatic vinyl compound being contained in an amount of 5 to 50% by weight based on the weight of the block copolymer and the olefinic elastomer block having a glass transition point of not higher than -20° C. and a heat of fusion of crystal of not more than 8 cal/g;

the ratio by weight between the component (a) and the component (b) being (a)/(b)=95/5 to 5/95.

Claims

1. A thermoplastic elastomer composition comprising the following two components:

(a) a thermoplastic polyurethane having soft segments from a poly(3-methyl-1,5-pentane adipate)diol having a molecular weight of at least 2,000 and having a JIS A hardness at 25°

C. of not more than 80, and

(b) a block copolymer comprising at least 2 polymer blocks A principally comprising an aromatic vinyl compound and at least 1 block B comprising an olefinic elastomer, said aromatic vinyl compound being contained in an amount of 5 to 50% by weight based on the weight of said block copolymer and said olefinic elastomer block having a glass transition point of not higher than -20°

C. and a heat of fusion of crystal of not more than 8 cal/g;

the ratio by weight between said component (a) and said component (b) being (a)/(b)=95/5 to 5/95.

2. The thermoplastic elastomer composition according to claim 1, wherein said block copolymer that constitutes component (b) has a molecular weight of 10,000 to 1,000,000.

3. The thermoplastic elastomer composition according to claim 1, wherein said block copolymer that constitutes component (b) has a molecular weight of 20,000 to 300,000.

4. The thermoplastic elastomer composition according to claim 1, wherein a glycol that forms a short chain component constituting said thermoplastic polyurethane that is component (a) .is ethylene glycol, 1,4-butanediol or 1,4-hexanediol.

5. The thermoplastic elastomer composition according to claim 1, wherein an isocyanate that forms a short chain component constituting said thermoplastic polyurethane that is component (a) is tolylene diisocyanate, isophorone diisocyanate or 4,4'"'"'-diphenylmethane diisocyanate.

6. The thermoplastic elastomer composition according to claim 1, wherein said aromatic vinyl compound is selected from the group consisting of styrene, α

-methylstyrene, o-, m- and p-methylstyrene, 1,3-dimethylstyrene, vinylnaphthalene and vinylanthracene.

7. The thermoplastic elastomer composition according to claim 1, wherein said olefinic elastomer block is a hydrogenation product of a polymer of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene or mixtures of the foregoing.

8. The thermoplastic elastomer composition according to claim 7, wherein said olefinic elastomer block is a hydrogenation product of a polymer of 1,3-butadiene, isoprene or mixtures of the foregoing.

9. The thermoplastic elastomer composition according to claim 1, wherein said olefinic elastomer block is a polymer of isobutylene or an α

-olefin.

10. The thermoplastic elastomer composition according to claim 1, wherein said thermoplastic polyurethane and said block copolymer are contained in a ratio by weight of [thermoplastic polyurethane]/[block copolymer] of 90/10 to 10/90.

11. The thermoplastic elastomer composition according to claim 10, wherein said thermoplastic polyurethane and said block copolymer are contained in a ratio by weight of [thermoplastic polyurethane]/[block copolymer] of 70/30 to 30/70.

12. The thermoplastic elastomer composition according to claim 7, wherein said polymer hydrogenation product is at least 70% saturated.