Process for elastomer viscosity stabilization

Claim 1

A process for stabilizing in the absence of vulcanizing agents the viscosity of chloroprene homopolymers and copolymers with ethylenically unsaturated monomers and of sulfur-modified chloroprene polymers, the proportion of ethylenically unsaturated monomers in the copolymer being at most about 20 weight %, and the proportion of elemental sulfur in the polymerization recipe being at most about 3.0 weight %, as well as blends of such chloroprene homopolymers and copolymers with hydrocarbon diene elastomers, wherein the proportion of the hydrocarbon diene elastomer is at most about 70 weight %; said process comprising incorporating into the chloroprene polymer or polymer blend about 0.1-5 parts per 100 parts by weight of the chloroprene polymer of a vinylenedicarbonyl compound represented by the following Formula (1) ##STR2## wherein the following relationships exist: (1) each of X and X' independently is --OR; --NR 1 R 2 ; or --R 3 , where R is a C 1 -C 12 alkyl, or a C 6 -C 15 aryl, aralkyl or alkaryl; each of R 1 and R 2 independently is H, a C 1 -C 12 alkyl, or a C 6 -C 15 aryl, aralkyl or alkaryl; and R 3 is a C 6 -C 15 aryl or alkaryl; or (2) X=--OH and X'=--NHR 4 , where R 4 is a C 1 -C 12 alkyl; or (3) X and X', taken together, form the --N(R 5 )-- group, where R 5 is a C 1 -C 18 alkyl, or a C 6 -C 15 aryl, aralkyl or alkaryl; and (4) each of Y and Y' independently is hydrogen or a halogen.