Abstract: An excellent cold-proof chlorosulfonated polyethylene and a method of manufacturing the same featured in that a polyethylene is once dissolved in a solvent by heating up them over a dissolution temperature of the polyethylene, then cooled and thus obtained homogeneous solution of the polyethylene is allowed to react with a sulfuryl chloride in the presence of a catalyst of a radical generating agent in the dissolution temperature region of the polyethylene or in a temperature region lower than the former one.

Abstract: A method for producing chlorosulfonated polyethylene with controlled addition of the amount of sulfur added to the polyethylene. Polyethylene dissolved in halogenated hydrocarbon is reacted with sulfuryl chloride in the presence of a catalyst of a radical generating agent in a binary phase system. The addition amount of sulfur is controlled by adding an amine compound to the reaction in an amount within the range where the following formula is applicable:log.sub.10 S=.alpha..multidot.log.sub.10 A+.beta. (1)whereinS: reaction yield (%) of sulfur of sulfuryl chlorideA: concentration (mol/liter) of amine compound in halogenated hydrocarbon solvent.alpha.,.beta.: constants such that1.0<.alpha.<3.04.0<.alpha.<12.0.

Abstract: Chlorosulfonated polyethylene having excellent properties as elastomer is produced by dissolving polyethylene in a mixed solvent of carbon tetrachloride and a halogenated aromatic compound such as, for example, chlorobenzene and reacting polyethylene with chlorine and sulfuryl chloride or with sulfuryl chloride.

Abstract: A chloroprene polymer composition comprises a benzene soluble chloroprene polymer (A) and a gel chloroprene polymer (B) at a ratio ranging from 20:1 to 1:1, wherein the benzene soluble chloroprene polymer (A) is obtained by an aqueous emulsion polymerization of chloroprene or a mixture of chloroprene and a comonomer with 0.05 to 5.0 wt. % of a molecular weight regulator in which the polymerization in the presence of effective amount of the molecular weight regulator is carried out to reach a conversion of 40 to 60% and then, 40 to 70 wt. % of the molecular weight regulator incorporated at the initiation of the polymerization is incorporated and the polymerization is continued to give a conversion of higher than 80% and the gel chloroprene polymer (B) is obtained by an aqueous emulsion polymerization of chloroprene or a mixture of chloroprene and a polyfunctional monomer.