Patent ID: 7348386
Filing Date: 2008-03-25
Classification: C08F,C08J,H01M,Y02E,Y02P

Abstract:
1. A method for producing a fluorocopolymer which comprises a polymerization reaction of a fluorine-containing ethylenic monomer with at least one fluorovinyl ether derivative represented by the following general formula (I): (wherein n represents an integer of 0 to 3, m represents an integer of 1 to 5, and A represents —SO 2 X or —COOY; X represents a halogen atom or —NR 1 R 2 ; R 1 and R 2 are the same or different and each represents a hydrogen atom, an alkali metal, an alkyl group or a sulfonyl-containing group and Y represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) to give a fluorocopolymer, said fluorine-containing ethylenic monomer being a perhaloethylenic monomer represented by the following general formula (II): (wherein R f 1 represents a fluorine atom, a chlorine atom, R f 2 or OR f 2 ; R f 2 represents a straight or branched perfluoroalkyl group having 1 to 9 carbon atoms, which may have an ether oxygen atom(s)) and/or a hydrogen-containing fluoroethylenic monomer represented by the following general formula (III): (wherein X 1 represents a hydrogen atom or a fluorine atom and X 2 represents a hydrogen atom, a fluorine atom, a chlorine atom, R f 3 or OR f 3 ; R f 3 represents a straight or branched perfluoroalkyl group having 1 to 9 carbon atoms, which may have an ether oxygen atom(s)) and said polymerization reaction being carried out in a saturated perfluorohydrocarbon while additional feeding of said fluorine-containing ethylenic monomer and said fluorovinyl ether derivative being carried out with the condition that the concentration ratio between the fluorine-containing ethylenic monomer and the fluorovinyl ether derivative in the reaction system is maintained at a constant or almost constant level so that a fluoropolymer is produced with minimized composition distribution and molecular weight distribution.