Process for the producing perfluorovinyl ethersulfonic acid derivatives and copolymer of the same

摘要

A compound of the formula (1): FSO2CFXCF2O(CFXCF2O)nCF-(CF2Y)COF in which X is a fluorine atom, a chlorine atom or a trifluoromethyl group, Y is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and n is a number of 0 to 5, preferably 0, 1 or 2, is converted to a compound of the formula (2): MOSO2CFXCF2O(CFXCF2O)2CF(CF2Y)COOM1 in which X, Y and n are the same as defined above, and M and M1 independently represent an alkali metal atom or an alkaline earth metal atom, and then a compound of the formula (2) is pyrolyzed at a temperature of 150 to 250° C. to obtain a compound of the formula (3): ASO2CFXCF2O(CFXCF2O)nCF=CF2 in which A is MO-, a hydroxyl group or a fluorine atom, and X and n are the same as defined above.