Resin composition, gasket material and gasket integrated with metal
First Claim
1. A resin composition which comprises a thermoplastic elastomer composition comprising 100 parts by weight of a (a1) hydrogenated block copolymer which is obtained by hydrogenating a block copolymer consisting essentially of at least one polymer block composed principally of a vinyl aromatic compound and at least one polymer block composed principally of a conjugated diene compound, which has a weight average molecular weight of at least 200,000, in which the at least one polymer block composed principally of a vinyl aromatic compound is polystyrene, and in which the content by weight of the polystyrene moiety that is contained in the hydrogenated block copolymer is in the range of 20 to 40% ;
- 100 to 200 parts by weight of a (b1) non-aromatic rubber-softening agent having a kinematic viscosity at 40°
C. of at least 300 mm2s−
1; and
10 to 50 parts by weight of a (c1) modified polyolefinic resin, said resin composition having a hardness as measured in accordance with JIS K6253 with a durometer of type A being at most 50 degrees and a compression set as measured in accordance with JIS K6262 after being allowed to stand at 70°
C. under a compression ratio of 25% for 22 hours being at most 50% .
1 Assignment
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Accused Products
Abstract
There are disclosed a resin composition which is excellent in rubber elasticity, oil maintainability and adhesivity to a metal, and comprises a thermoplastic elastomer composition comprising a (a1) hydrogenated block copolymer which is obtained by hydrogenating a block copolymer consisting essentially of a polymer block composed principally of a vinyl aromatic compound and a polymer block composed principally of a conjugated diene compound, which has a weight average molecular weight of at least 200,000, in which the polymer block composed principally of a vinyl aromatic compound is polystyrene, and in which the content by weight of the polystyrene moiety contained in the hydrogenated block copolymer is 20 to 40% ; a (b1) non-aromatic rubber-softening agent having a kinematic viscosity at 40° C. of at least 300 mm2s-1; and a (c1) modified polyolefinic resin, the resin composition having a hardness according to JIS K6253 of at most 50 degrees and a compression set according to JIS K6262 of at most 50% ; a composite molded body of a metal and the thermo-plastic elastomer composition such as a gasket integrated with a metallic sheet; and processes for producing the above products.
19 Citations
36 Claims
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1. A resin composition which comprises a thermoplastic elastomer composition comprising 100 parts by weight of a (a1) hydrogenated block copolymer which is obtained by hydrogenating a block copolymer consisting essentially of at least one polymer block composed principally of a vinyl aromatic compound and at least one polymer block composed principally of a conjugated diene compound, which has a weight average molecular weight of at least 200,000, in which the at least one polymer block composed principally of a vinyl aromatic compound is polystyrene, and in which the content by weight of the polystyrene moiety that is contained in the hydrogenated block copolymer is in the range of 20 to 40% ;
- 100 to 200 parts by weight of a (b1) non-aromatic rubber-softening agent having a kinematic viscosity at 40°
C. of at least 300 mm2s−
1; and
10 to 50 parts by weight of a (c1) modified polyolefinic resin, said resin composition having a hardness as measured in accordance with JIS K6253 with a durometer of type A being at most 50 degrees and a compression set as measured in accordance with JIS K6262 after being allowed to stand at 70°
C. under a compression ratio of 25% for 22 hours being at most 50% . - View Dependent Claims (2, 3, 4, 5, 6, 7)
- 100 to 200 parts by weight of a (b1) non-aromatic rubber-softening agent having a kinematic viscosity at 40°
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8. A thermoplastic elastomer composition comprising 100 parts by weight of a (a2) hydrogenated block copolymer which is obtained by hydrogenating a block copolymer consisting essentially of at least one polymer block composed principally of a vinyl aromatic compound and at least one polymer block composed principally of a conjugated diene compound, which has a weight average molecular weight of at least 200,000, in which the at least one polymer block composed principally of a vinyl aromatic compound is polystyrene and in which the content by weight of the polystyrene moiety that is contained in the hydrogenated block copolymer is in the range of 20 to 40% ;
- 100 to 200 parts by weight of a (b2) non-aromatic rubber-softening agent having a kinematic viscosity at 40°
C. of at least 300 mm2s−
1;
10 to 50 parts by weight of a (c2) modified hydrogenated block copolymer obtained by hydrogenating a block copolymer in which a functional group is imparted to a block copolymer consisting essentially of at least one polymer block composed principally of a vinyl aromatic compound and at least one polymer block composed principally of a conjugated diene compound; and
0 to 20 parts by weight of a (d2) compound composed principally of a crystalline polyolefin, said thermoplastic elastomer composition having a hardness as measured in accordance with JIS K6253 with a durometer of type A being at most 50 degrees and a compression set as measured in accordance with JIS K6262 after being allowed to stand at 70°
C. under a compression ratio of 25% for 22 hours being at most 50% . - View Dependent Claims (9, 10, 11, 12, 13, 14)
- 100 to 200 parts by weight of a (b2) non-aromatic rubber-softening agent having a kinematic viscosity at 40°
-
15. A composite molded body that is formed by integrating through thermally fusing adhesion, a metallic sheet laminated with a thermoplastic resin having a hardness as measured in accordance with JIS K6253 with a durometer of type A of at least 50 degrees;
- and a thermoplastic elastomer composition having a hardness as measured in accordance with JIS K6253 with a durometer of type A being at most 60 degrees and a compression set as measured in accordance with JIS K6262 after being allowed to stand at 70°
C. under a compression ratio of 25% for 22 hours being at most 50%. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
- and a thermoplastic elastomer composition having a hardness as measured in accordance with JIS K6253 with a durometer of type A being at most 60 degrees and a compression set as measured in accordance with JIS K6262 after being allowed to stand at 70°
- 23. A process for producing a composite molded body of a resin and metal which comprises subjecting part or all of the surface of a metallic part that comes into contact with a resin portion to a corona treatment or a plasma treatment, thereafter placing the metallic part thus treated in a mold, and then injecting a thermoplastic elastomer composition onto the surfaces of the metallic part placed in the mold to form the resin portion.
- 30. A process for producing a gasket integrated with a cover by placing a metallic cover in a mold, and injecting a gasket material composed of a thermoplastic elastomer composition onto the surface of said cover so as to form a gasket portion, characterized in that the thermoplastic elastomer composition is injection cast from a direction different from the direction towards a butt contact surface on the gasket portion upon the use thereof.
Specification