| abstract |
Disclouse is an olefin thermoplastic elastomer foamed product obtained by heating a foamable composition comprising a partially crosslinked thermoplastic elastomer composition (A), a specific olefin plastic (B) and a foaming agent (C) in specific proportions. The partially crosslinked thermoplastic elastomer (A) is obtained by dynamically heat-treating a mixture in the presence of organic peroxide, said mixture comprising specific proportions of a peroxide-crosslinkable copolymer rubber (a), which is a specific ethylene/ alpha -olefin/nonconjugated diene copolymer rubber, and a peroxide-decomposable olefin plastic (b), which is a (co)polymer containing 50 to 100% by mol of an alpha -olefin of 3 to 20 carbon atoms and has a specific MFR. The olefin plastic (B) is a (co)polymer containing 50 to 100% by mol of an alpha -olefin of 2 to 20 carbon atoms and has a specific MFR. Also disclosed is a process for preparing the olefin thermoplastic elastomer foamed product. The foamed product of the invention is free from surface roughening caused by defoaming even when an expansion ratio is 2 or more times. Besides, the foamed product is soft to the touch and shows excellent heat resistance and weathering resistance. According to the process of the invention, the foamed product can be prepared through simplified steps with high productivity. |