PROCESS FOR PRODUCING FLUOROELASTOMER

摘要

A fluoroelastomer is produced by polymerization reaction of a fluorinated olefin with the use of any of ?H perfluorocarboxylic acids of the general formula H(CF2)nCOOM (wherein M is a hydrogen atom, an alkali metal or an ammonium group, and n is 6, 7 or 8) or its salt as an emulsifier. The thus produced fluoroelastomer, as a result of the polymerization reaction of a fluorinated olefin with the use of ?H perfluorocarboxylic acid (salt) as an emulsifier, is low in the Mooney viscosity ML1+10 (121°C) to thereby improve the fluidity being essential for injection molding material. Thus, the productivity in injection molding can be enhanced. Further, any marked lowering is not observed in the polymerization rate during the polymerization reaction, and any deterioration is not observed in the physical properties, such as tensile strength, compression set resistance performance and hot tear resistance, of vulcanization product.