Abstract: The application provides a process for preparing a thermoplastic elastomer composition (F) for injection molding, comprising dynamically heat-treating a thermoplastic elastomer composition (D), which comprises 95 to 5 parts by weight of an ethylene/?-olefin-based copolymer rubber (a), 5 to 95 parts by weight of a propylene/?-olefin random copolymer (b-1) (total of the components (a) and (b-1): 100 parts by weight), and 0 to 200 parts by weight of a softener (c), in the presence of an organic peroxide, wherein a crystallization nucleating agent (e) for olefin-based plastics is added in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the total of the components (a) and (b-1) before or after the dynamic heat treatment.

Abstract: Disclosed is a thermoplastic elastomer composition containing 10-60 parts by weight of a non-crosslinkable crystalline polyolefin resin (A), 1-30 parts by weight of a specific propylene 1-butene random copolymer (B) and 89-10 parts by weight of an ethylene ?-olefin non-conjugated polyene copolymer rubber (C) which is composed of ethylene, an ?-olefin having 3-20 carbon atoms and a non-conjugated polyene, in such amounts that the total of the components (A), (B) and (C) is 100 parts by weight. The thermoplastic elastomer composition is dynamically crosslinked by an extruder. This thermoplastic elastomer is excellent in moldability and economic efficiency, and enables to obtain a molded body exhibiting sufficient adhesion strength to a vulcanized rubber or thermoplastic elastomer without the intermediation of an adhesive layer, as well as a lightweight molded body having sufficient hardness and rubber elasticity.

Abstract: Disclosed is a thermoplastic elastomer composition containing 10-60 parts by weight of a non-crosslinkable crystalline polyolefin resin (A), 1-30 parts by weight of a specific propylene 1-butene random copolymer (B) and 89-10 parts by weight of an ethylene ?-olefin non-conjugated polyene copolymer rubber (C) which is composed of ethylene, an ?-olefin having 3-20 carbon atoms and a non-conjugated polyene, in such amounts that the total of the components (A), (B) and (C) is 100 parts by weight. The thermoplastic elastomer composition is dynamically crosslinked by an extruder. This thermoplastic elastomer is excellent in moldability and economic efficiency, and enables to obtain a molded body exhibiting sufficient adhesion strength to a vulcanized rubber or thermoplastic elastomer without the intermediation of an adhesive layer, as well as a lightweight molded body having sufficient hardness and rubber elasticity.

Abstract: [PROBLEM] To provide a process for preparing a thermoplastic elastomer composition which is inhibited from sink mark in the injection welding of a linear part and a corner part of a glass run channel and has excellent bond properties, and a molded product obtained by the use of the composition. [MEANS FOR SOLVING PROBLEM] A process for preparing a thermoplastic elastomer composition (F) for injection molding, comprising dynamically heat-treating a thermoplastic elastomer composition (D), which comprises 95 to 5 parts by weight of an ethylene/?-olefin-based copolymer rubber (a), 5 to 95 parts by weight of a propylene/?-olefin random copolymer (b-1) (total of the components (a) and (b-1): 100 parts by weight), and 0 to 200 parts by weight of a softener (c), in the presence of an organic peroxide, wherein a crystallization nucleating agent (e) for olefin-based plastics is added in an amount of 0.