| 摘要 |
An olefinic thermoplastic elastomer foam of the present invention has a density of less than 700 kg/m<3>, a compression set of less than 60% and a density of elastically effective chains v of preferably 3.0x10<-5 >to 2.0x10<-4 >(mol/cm<3>). An olefinic thermoplastic elastomer composition for preparing the above foam has an equilibrium creep compliance Je<0 >of 1.0x10<-6 >to 5.0x10<-4 >(Pa<-1>) and contains a crosslinked olefin rubber and an olefin plastic in a specific proportion. The olefinic thermoplastic elastomer composition can be prepared by melt kneading a specific crosslinked olefinic thermoplastic elastomer and a specific olefin plastic. The olefinic thermoplastic elastomer composition is preferably foamed by at least one foaming agent selected from an organic or inorganic thermally decomposable foaming agent, carbon dioxide and nitrogen, together with a specific foaming auxiliary such as citric acid. The olefinic thermoplastic elastomer foam is particularly suitable to use as an automotive sponge weatherstrip, a clearance-filling foamed sheet, a building sash sponge seal, a pipe-joint sponge seal, a protect sponge or a thermal insulating sponge tube. The olefinic thermoplastic elastomer composition according to the invention can provide the foams which have no surface roughness, a low density and a low compression set, preferably a good appearance and a kink resistance. The olefinic thermoplastic elastomer foams can be used as substitutes for vulcanized rubbers.
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