Patent ID: 9475895
Filing Date: 2016-10-25
CPC Classification: C08C,C08F,C08K

Claim Text:
1. A sulfur-modified chloroprene rubber composition, comprising a sulfur-modified chloroprene rubber containing sulfur chemically bound thereto and sulfur not chemically bound to the sulfur-modified chloroprene rubber, wherein: at least one compound selected from dialkylxanthogen disulfides, and alkylmercaptans is used as a chain-transfer agent during polymerization of chloroprene; the amount of the chain-transfer agent is 0.05 to 0.2 parts by mass with respect to 100 parts by mass of all monomers to be polymerized; the polymerization is carried out to a polymerization degree in the range of 75 to 95%; the ratio of the amount of sulfur chemically bound to the sulfur-modified chloroprene rubber to the total amount of sulfur in the sulfur-modified chloroprene rubber composition (amount of chemically bound sulfur [mass %]/total amount of sulfur [mass %]) is 0.1 to 0.45; and the sulfur-modified chloroprene rubber has, at the molecular terminal, at least one structure represented by the following General Formula (1) or (2): (in General Formula (1), R1 represents an alkyl group having 1 to 4 carbon atoms) or (in General Formula (2), R2 represents an alkyl group having 8 to 20 carbon atoms).