Method for producing a fluoroelastomer

Abstract

The present invention provides a method for producing a fluoroelastomer using an emulsifier which is inexpensive and hardly remains in product polymers. The present invention is related to a method for producing a fluoroelastomer, wherein vinylidene fluoride and at least one fluoroolefin monomer other than vinylidene fluoride are copolymerized in the manner of an emulsion polymerization in the presence of an emulsifier represented by C5F11COOM, wherein M represents H, NH4 or an alkali metal.

Description

technical field

[0001] The present invention relates to a method for producing fluoroelastomers. Background technique

[0002] In the emulsion polymerization of fluoroelastomers, perfluoro fatty acids and their derivatives are widely used as emulsifiers, and ammonium perfluorooctanoate (C 7 f 15 COONH 4 ). Ammonium perfluorooctanoate has excellent emulsion polymerizability, but it is expensive and tends to remain in the resulting polymer during coagulation, making the vulcanization of the rubber composition for vulcanization slow and time-consuming, or the characteristics of the obtained vulcanized compound deteriorated, Therefore, it is necessary to perform a sufficient washing process before drying.

[0003] In Patent Document 1, it is described that the use of C 6 f 13 CH 2 CH 2 SO 3 M was used as an alternative emulsifier for ammonium perfluorooctanoate, but it was found that the polymer changed, which was thought to be caused by the chain transfer reaction of m...