Provided is a thermoplastic elastomer composition with which it is possible to obtain a molded article having exceptional low-temperature impact resistance. A thermoplastic elastomer composition is produced that contains a crystalline olefin polymer (A) and an ethylene--olefin (C.sub.4-.sub.20)unconjugated polyene copolymer (B) that satisfies requirements (1) and (2). (1) The B value represented by the equation: ([EX]+2[Y])/(2[E]([X]+[Y])) is 1.20 or higher. [E], [X] and [Y] respectively indicate the molar fraction of structural units derived from ethylene, the molar fraction of structural units derived from C.sub.4-.sub.20 -olefin and the molar fraction of structural units derived from unconjugated polyene, and [EX] indicates the diad chain fraction of structural units derived from ethylene-structural units derived from C.sub.4-.sub.20 -olefin. (2) The molar ratio of structural units derived from ethylene with respect to structural units derived from -olefin (C.sub.4-.sub.20) of copolymer (B) is 40/60-90/10.

Provided is a thermoplastic elastomer composition with which it is possible to obtain a molded article having exceptional low-temperature impact resistance. A thermoplastic elastomer composition is produced that contains a crystalline olefin polymer (A) and an ethylene--olefin (C.sub.4-.sub.20)unconjugated polyene copolymer (B) that satisfies requirements (1) and (2). (1) The B value represented by the equation: ([EX]+2[Y])/(2[E]([X]+[Y])) is 1.20 or higher. [E], [X] and [Y] respectively indicate the molar fraction of structural units derived from ethylene, the molar fraction of structural units derived from C.sub.4-.sub.20 -olefin and the molar fraction of structural units derived from unconjugated polyene, and [EX] indicates the diad chain fraction of structural units derived from ethylene-structural units derived from C.sub.4-.sub.20 -olefin. (2) The molar ratio of structural units derived from ethylene with respect to structural units derived from -olefin (C.sub.4-.sub.20) of copolymer (B) is 40/60-90/10.

[Problem] The purpose of the invention is to provide: a thermoplastic elastomer composition capable of providing molded articles that are lightweight, have better oil resistance than those provided by conventional cross-linked thermoplastic elastomers, and have hardness and mechanical properties such as tensile strength and tensile elongation that are equal to or superior to those provided by conventional cross-linked thermoplastic elastomers; and an ethylene/-olefin/unconjugated polyene copolymer having little compression set at low temperature as well as flexibility and an excellent balance of rubber elasticity at low temperature and tensile strength at normal temperature.

[Solution] Produced are: a thermoplastic elastomer composition obtained by dynamically crosslinking a mixture containing a crystalline olefin polymer (A), an ethylene/-olefin (having 4-20 carbon atoms)/unconjugated polyene copolymer (1B) that satisfies specific requirements, and a phenol resin-based crosslinking agent (C); and an ethylene--olefin/unconjugated polyene copolymer (2B) that satisfies specific requirements.

[Problem] The purpose of the invention is to provide: a thermoplastic elastomer composition capable of providing molded articles that are lightweight, have better oil resistance than those provided by conventional cross-linked thermoplastic elastomers, and have hardness and mechanical properties such as tensile strength and tensile elongation that are equal to or superior to those provided by conventional cross-linked thermoplastic elastomers; and an ethylene/-olefin/unconjugated polyene copolymer having little compression set at low temperature as well as flexibility and an excellent balance of rubber elasticity at low temperature and tensile strength at normal temperature.

[Solution] Produced are: a thermoplastic elastomer composition obtained by dynamically crosslinking a mixture containing a crystalline olefin polymer (A), an ethylene/-olefin (having 4-20 carbon atoms)/unconjugated polyene copolymer (1B) that satisfies specific requirements, and a phenol resin-based crosslinking agent (C); and an ethylene--olefin/unconjugated polyene copolymer (2B) that satisfies specific requirements.

The present invention relates to a multimodal polyethylene composition, a sheet and a hollow article comprising the same, a method for preparing the sheet or the hollow article, and the use of the sheet or the hollow article.

A curable composition includes an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying conditions (1) to (4) and an additive resin, which is a polyphenylene ether. (1) The number average molecular weight of the copolymer is 5000 to 100000. (2) The aromatic vinyl compound monomer has 8 to 20 carbon atoms, and the content of the unit of the monomer is 0 to 70 mass %. (3) The aromatic polyene is selected from polyenes having 5 to 20 carbon atoms and a plurality of vinyl and/or vinylene groups in the molecule, and the content of the groups is 1.5 to 20 pieces per number average molecular weight. (4) The olefin is selected from olefins having 2 to 20 carbon atoms, and the total monomer units of the olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %.

A curable composition includes an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying conditions (1) to (4) and an additive resin, which is a polyphenylene ether. (1) The number average molecular weight of the copolymer is 5000 to 100000. (2) The aromatic vinyl compound monomer has 8 to 20 carbon atoms, and the content of the unit of the monomer is 0 to 70 mass %. (3) The aromatic polyene is selected from polyenes having 5 to 20 carbon atoms and a plurality of vinyl and/or vinylene groups in the molecule, and the content of the groups is 1.5 to 20 pieces per number average molecular weight. (4) The olefin is selected from olefins having 2 to 20 carbon atoms, and the total monomer units of the olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %.

A laminate has an olefin-aromatic vinyl compound-aromatic polyene copolymer and a metal foil. The number average molecular copolymer weight is between 5000 and 100000; the aromatic vinyl compound monomer is aromatic vinyl compound having between 8 and 20 carbon atoms, and the aromatic vinyl compound monomer unit content is between 10 and 60 mass %; the aromatic polyene is selected having between 5 and 20 carbon atoms and vinyl and/or vinylene groups in the molecule, the content derived from the aromatic polyene unit is between 1.5 and 20 pieces per number average molecular weight; and the olefin is selected having between 2 and 20 carbon atoms, being ethylene alone, or having a mass ratio of -olefin monomer components other than ethylene to an ethylene monomer component contained in the olefin, of 1/7 or less, and the total monomer units of the olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %.

A laminate has an olefin-aromatic vinyl compound-aromatic polyene copolymer and a metal foil. The number average molecular copolymer weight is between 5000 and 100000; the aromatic vinyl compound monomer is aromatic vinyl compound having between 8 and 20 carbon atoms, and the aromatic vinyl compound monomer unit content is between 10 and 60 mass %; the aromatic polyene is selected having between 5 and 20 carbon atoms and vinyl and/or vinylene groups in the molecule, the content derived from the aromatic polyene unit is between 1.5 and 20 pieces per number average molecular weight; and the olefin is selected having between 2 and 20 carbon atoms, being ethylene alone, or having a mass ratio of -olefin monomer components other than ethylene to an ethylene monomer component contained in the olefin, of 1/7 or less, and the total monomer units of the olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %.

A rubber composition is based on at least an elastomer matrix predominantly comprising a highly saturated diene elastomer, a reinforcing filler, a vulcanization system, and a plasticizing system comprising a hydrocarbon resin having a Tg between 40 C. and 20 C. and a number-average molar mass (Mn) of less than or equal to 800 g/mol, the highly saturated diene elastomer being a copolymer of ethylene and of at least one 1,3-diene in which the ethylene units represent at least 50 mol % of the monomer units of the copolymer.