Thermoplastic elastomer composition and process for preparation thereof

A thermoplastic elastomer composition having excellent injection fusion bondability and surface gloss, which comprises:

• (1) an ethylene/propylene/2-ethylene-5-norbornene terpolymer having an ethylene unit content of 50 to 95 mole%, a propylene unit content of 5 to 50 mole%, a 2-ethylene-5-norbornene unit content of 0.1 to 20 mole%, a crystallization degree lower than 20% and a Mooney Viscosity (ML.sub.1+4 (100.degree. C.)) of 40 to 160, and
• (2) a combination of (b) of low crystalline copolymer of propylene and 1-butene having a propylene unit content of 55 to 85 mole%, and a melt flow rate of 1 to 40 g/10 min, and
• (c) polypropylene having a crystallization higher than 50%
• wherein component (1) is present in an amount of 10 to 95% by weight based on the total amount of components (1) and (2), component (2) is present in an amount of 5 to 90% by weight based on the total amount of components (1) and (2), the weight ratio of component (b)/component (c) is in the range of 80/20 to 20/80, the component (1) is partially cross-linked by kneading components (1) and (c) in the molten state in the presence of a radial-polymerizable monomer (e) having at least two polymerizable groups and an organic peroxide (f), each of the amounts of the monomer (e) and the peroxide being 0.1 to 1 part by weight per 100 parts by weight of the total amount of the components (1) and (c), and said elastomer composition is obtained by kneading the partially cross-linked composition comprising components (1) and (c) with the component (b).

A thermoplastic elastomer composition having excellent injection fusion bondability and surface gloss, which comprises:

• (1) an ethylene/propylene/2-ethylidene-5-norbornene terpolymer having an ethylene unit content of 50 to 95 mole%, a propylene unit content of 5 to 50 mole%, a crystallization degree lower than 20% and a Mooney Viscosity (ML.sub.1+4 (100.degree. C.)) of 40 to 160, and
• (2) a combination of (b) of low crystalline copolymer of propylene and 1-butene having a propylene unit content of 55 to 85 mole%, and a melt flow rate of 1 to 40 g/10 min, and
• (c) polypropylene having a crystallization higher than 50%, and
• (3) a minor amount of isobutene/isoprene copolymer rubber
• wherein component (1) is present in an amount of 10 to 95% by weight based on the total amount of components (1) and (2), component (2) is present in an amount of 5 to 90% by weight based on the total amount of components (1) and (2), the weight ratio of component (b)/component (c) is in the range of 80/20 to 20/80, the component (1), is partially cross-linked by kneading the components (1), (c) and (3) in the molten state in the presence of a radical-polymerizable monomer (e) having at least two polymerizable groups and an organic peroxide (f), each of the amounts of the monomer (e) and the peroxide being 0.1 to 1 part by weight per 100 parts by weight of the total amount of the components (1), (c) and (3), and said elastomer composition is obtained by kneading the partially cross-linked composition comprising components (1), (c) and (3) with the component (b).

A thermoplastic elastomer composition having excellent injection fusion bondability and surface gloss, which comprises:

• (1) an ethylene/propylene/unconjugated diene terpolymer having an ethylene unit content of 50 to 95 mole%, a propylene unit content of 5 to 50 mole%, an unconjugated diene unit content of 0.1 to 20 mole%, a crystallization degree lower than 20% and a Mooney Viscosity (ML.sub.1+4 (100.degree. C.)) of 40 to 160, and
• (2) a combination of (b) of low crystalline copolymer of propylene and 1-butene copolymer, and
• (c) crystalline polypropylene
• wherein component (1) is present in an amount of 10 to 95% by weight based on the total amount of components (1) and (2), component (2) is present in an amount of 5 to 90% by weight based on the total amount of components (1) and (2), the weight ratio of component (b)/component (c) is in the range of 80/20 to 20/80, and the component (1) is partially cross-linked.

A thermoplastic elastomer composition having excellent injection fusion bondability and surface gloss, which comprises:

• (1) an ethylene/propylene/nonconjugated diene terpolymer having an ethylene unit content of 50 to 95 mole%, a propylene unit content of 5 to 50 mole%, a nonconjugated diene unit content of 0.1 to 20 mole%, a crystallization degree lower than 20% and a Mooney Viscosity (ML.sub.1+4 (100.degree. C.)) of 40 to 160, and
• (2) a combination of (b) of propylene/1-butene copolymer having a propylene unit content of 55 to 85 mole%, a crystallization degree of lower than 40% and a melt flow rate of 1 to 40 g/10 min, and
• (c) polypropylene having a crystallization higher than 50%
• wherein component (1) is present in an amount of 10 to 95% by weight based on the total amount of components (1) and (2), component (2) is present in an amount of 5 to 90% by weight based on the total amount of components (1) and (2), the weight ratio of component (b)/component (c) is in the range of 80/20 to 20/80, the component (1) is partially cross-linked.

A thermoplastic elastomer composition having excellent injection fusion bondability and surface gloss, which comprises:

• (1) an ethylene/propylene/nonconjugated diene terpolymer having an ethylene unit content of 50 to 95 mole%, a propylene unit content of 5 to 50 mole%, a nonconjugated diene unit content of 0.1 to 20 mole%, a crystallization degree lower than 20% and a Mooney Viscosity (ML.sub.1+4 (100.degree. C.)) of 40 to 160, and
• (2) a combination of (b) of low crystalline copolymer of propylene and 1-butene copolymer, and
• (c) polypropylene having a crystallization higher than 50%, and
• (3) a minor amount of isobutene/isoprene copolymer rubber and/or softener
• wherein component (1) is present in an amount of 10 to 95% by weight based on the total amount of components (1) and (2), component (2) is present in an amount of 5 to 90% by weight based on the total amount of components (1) and (2), the weight ratio of component (b)/component (c) is in the range of 80/20 to 20/80, the component (1) is partially cross-linked.