Polymer composition and uses thereof

• US 20050239963A1
• Filed: 04/21/2003
• Published: 10/27/2005
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Maeda, Mizuho, Wada, Koichi, Shachi, Kenji, Kitano, Hajime, Higashida, Noboru
• Granted Patent: US 7,247,674 B2
• Time in Patent Office: Days
• US Class Current: 525/88
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: C08F 297/00 Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
• CPC Class Codes: C08F 297/02 using a catalyst of the anionic type
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 33/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• 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 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31917 Next to polyene polymer
• CPC Class Codes: Y10T 428/31924 Including polyene monomers
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

The present invention concerns a polymer composition comprising: a block copolymer (a) including a polymer block A, which is composed mainly of an α-methylstyrene, and a hydrogenated or unhydrogenated polymer block B, which is composed of a conjugated diene or isobutylene and has a weight average molecular weight of 30,000 to 200,000; an acrylic resin (b); and a softener (c), wherein proportions (by mass) of the respective components in the polymer composition are such that each of the following relationships (1) and (2) holds:
0.05≦Wb/Wa≦2  (1)
and
Wc/(Wa+Wb+Wc)≦0.5  (2) wherein Wa, Wb, and Wc represent amounts (by mass) of the block copolymer (a), the acrylic resin (b) and the softener (c), respectively. The polymer composition obtainable in accordance with the present invention is favorable in terms of such physical properties as formability, scratch resistance, abrasion resistance, flexibility, mechanical strength, rubber elasticity, and transparency and exhibits these properties in a well-balanced manner. By exploiting these favorable properties, the polymer composition can be effectively used in a wide range of applications, including stretchable materials, laminates, and foams.

Claims

1. A polymer composition comprising:

a block copolymer (a) comprising a polymer block A, which is composed mainly of an α

-methylstyrene, and a hydrogenated or unhydrogenated polymer block B, which is composed of a conjugated diene or isobutylene and has a weight average molecular weight of 30,000 to 200,000;

an acrylic resin (b); and

a softener (c); and

wherein proportions (by mass) of respective components in the polymer composition are such that each of the following relationships (1) and (2) holds;

0.05≦

Wb/Wa≦

2 

 

(1)
and
Wc/(Wa+Wb+Wc)≦

0.5 

 

(2)

wherein Wa, Wb, and Wc represent the amounts (by mass) of the block copolymer (a), the acrylic resin (b) and the softener (c), respectively.

2. The polymer composition according to claim 1, wherein the block copolymer (a) comprises:

(1) a polymer block A composed mainly of an α

-methylstyrene and having a weight average molecular weight of 1,000 to 50,000; and

(2) a polymer block B including a block b1 that has a weight average molecular weight of 1,000 to 30,000, and in which less than 30% of the conjugated diene units to constitute the block are linked via 1,4-linkages, and a block b2 that has a weight average molecular weight of 25,000 to 190,000% and in which 30% or more of the conjugated diene units to constitute the block are linked via 1,4-linkages; and

wherein the block copolymer (a) includes at least one A-b1-b2 structure.

3. The polymer composition according to claim 1, wherein the polymer composition has a morphology in which the block copolymer (a) forms a continuous phase (matrix) and the acrylic resin (b) forms particles having an average particle size of 0.2 μ

m or less, that are dispersed throughout the continuous phase, forming sea-island structures, the block copolymer (a) having the polymer block A composed mainly of an α

-methylstyrene, and the hydrogenated or unhydrogenated polymer block B composed of the conjugated diene or isobutylene, the block copolymer (a) having a weight average molecular weight of 30,000 to 200,000.

4. A stretchable material formed of the polymer composition according to claim 1.

5. The stretchable material according to claim 4, wherein the stretchable material is provided in the form of a film, strand, band, or nonwoven fabric formed of the polymer composition.

6. The stretchable material according to claim 4, wherein the stretchable material yields a 0.8 MPa or larger stress when formed into a 1 mm thick, No. 2 dumbbell-molded sample piece, according to JIS K 6251, and stretched by 50% at a test speed of 20 mm/min at 25°

C., with the grip distance of 70 mm, and gives a 50% or higher stress retention after held under the conditions for 2 hours.

7. A laminate comprising a layer formed of the polymer composition according to claim 1, and a layer formed of a different material.

8. The laminate according to claim 7, wherein the different material is a thermoplastic resin.

9. The laminate according to claim 8, wherein the different material comprises at least one thermoplastic resin selected from the group consisting of olefin-based resin, olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, and a resin composition containing a styrene-based thermoplastic elastomer.

10. A laminate comprising an outermost layer formed of the polymer composition according to claim 1, and a layer formed of a different material.

11. A foam composition comprising the polymer composition according to claim 1, and a blowing agent (d), and wherein the blowing agent (d) is contained in a proportion (by mass), such that the following relationship (3) holds:

0.01≦

Wd/(Wa+Wb+Wc)≦

0.1 

 

(3)

wherein Wa, Wb, Wc, and Wd represent the amounts (by mass) of the block copolymer (a), the acrylic resin (b), the softener (c), and the blowing agent (d) that together form the foam composition, respectively.

12. A foam obtained by foaming the foam composition according to claim 11.

13. The polymer composition according to claim 2, wherein the polymer composition has a morphology in which the block copolymer (a) forms a continuous phase (matrix) and the acrylic resin (b) forms particles having an average particle size of 0.2 μ

m or less, that are dispersed throughout the continuous phase, forming sea-island structures, the block copolymer (a) having the polymer block A composed mainly of an α

-methylstyrene, and the hydrogenated or unhydrogenated polymer block B composed of the conjugated diene or isobutylene, the block copolymer (a) having a weight average molecular weight of 30,000 to 200,000.

14. A stretchable material formed of the polymer composition according to claim 2.

15. A stretchable material formed of the polymer composition according to claim 3.

16. A laminate comprising a layer formed of the polymer composition according to claim 2, and a layer formed of a different material.

17. A laminate comprising a layer formed of the polymer composition according to claim 3, and a layer formed of a different material.

18. A laminate comprising an outermost layer formed of the polymer composition according to claim 2, and a layer formed of a different material.

19. A laminate comprising an outermost layer formed of the polymer composition according to claim 3, and a layer formed of a different material.

20. A foam composition comprising the polymer composition according to claim 2, and a blowing agent (d), and wherein the blowing agent (d) is contained in a proportion (by mass), such that the following relationship (3) holds:

0.01≦

Wd/(Wa+Wb+Wc)≦

0.1 

 

(3)

wherein Wa, Wb, Wc, and Wd represent the amounts (by mass) of the block copolymer (a), the acrylic resin (b), the softener (c), and the blowing agent (d) that together form the foam composition, respectively.