Abstract: A chlorosulfonated ethylene-.alpha.-olefin copolymer composition comprising a chlorosulfonated ethylene-.alpha.-olefin copolymer, a thiuram compound, a bismaleimide compound, a nickel dialkyldithiocarbamate, and a diarylmonoamine compound, and a motorcar joint boot obtained by molding and vulcanizing the chlorosulfonated ethylene-.alpha.-olefin copolymer composition. The copolymer composition is excellent in the tensile characteristics at room temperature and low temperature, in the compression set under a low-temperature atmosphere, and in the fatigue resistance.

Abstract: A chlorosulfonated ethylene-.alpha.-olefin copolymer composition comprising a chlorosulfonated ethylene-.alpha.-olefin copolymer, a thiuram compound, a bismaleimide compound, a nickel dialkyldithiocarbamate, and a diarylmonoamine compound, and a motorcar joint boot obtained by molding and vulcanizing the chlorosulfonated ethylene-.alpha.-olefin copolymer composition. The copolymer composition is excellent in the tensile characteristics at room temperature and low temperature, in the compression set under a low-temperature atmosphere, and in the fatigue resistance.

Abstract: An acrylic copolymer rubber which is a random copolymer of(A) a cyano group-containing acrylate or methacrylate of the following formula (I): ##STR1## wherein R.sup.1 is hydrogen or methyl, and R.sup.2 is --C.sub.n H.sub.2n -- or --CH.sub.2 CH.sub.2 --0--CH.sub.2 CH.sub.2 --, wherein n is an integer of from 2 to 4,(B) at least one of ethyl acrylate and n-butyl acrylate, and(C) at least one of glycidyl methacrylate and allyl glycidyl ether, or vinyl chloroacetate,wherein the amounts of units derived from the above (A), (B) and (C) in said copolymer are from 5 to 70% by weight, from 20 to 94.5% by weight and from 0.5 to 10% by weight, respectively, and which has a Mooney viscosity ML.sub.1+4 (100.degree. C.) of at least 5.

Abstract: An acrylic copolymer elastomer is disclosed, comprising (A) from 94.5 to 50% by weight of ethyl arcylate or ethyl arcylate containing not more than 50% by weight of n-butyl acrylate, (B) from 5 to 50% by weight of an arcylic acid ester and/or a methacrylic acid ester represented by formula (I): ##STR1## wherein the symbols are as defined in the appended claims, and (C) from 0.5 to 10% by weight of at least one of allyl glycidyl ether and glycidyl methacrylate, or vinyl chloroacetate, and having a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of at least 10. This is a novel copolymer elastomer which is excellent in fuel resistance and low-temperature resistance.