Abstract: Provided is a process for producing a fluoropolymer containing repeating units based on a fluoromonomer represented by the following formula (m) in an amount of from 5 to 50 mol % based on the entire repeating units in the polymer by polymerization reaction of tetrafluoroethylene and the fluoromonomer, wherein the polymerization reaction is carried out by continuously charging the reactor with tetrafluoroethylene and the fluoromonomer: wherein ml is an integer of from 1 to 6. Also provided is an electrolyte material for an electrolyte fuel cell which can be operated at a high temperature to obtain a high output, wherein the electrolyte material contains the fluoropolymer produced by the process.

Abstract: To provide a process for producing a perfluorocarbon polymer, whereby a perfluorocarbon polymer having a high content of —SO2F groups and a high molecular weight can be efficiently obtained. The process comprises polymerizing a monomer mixture comprising the liquid monomer (A) of the following formula (1) and tetrafluoroethylene at a polymerization temperature of from 25 to 45° C. by sequentially or continuously adding an initiator of the following formula (2): CF2?CF(OCF2CFX1)k—O1—(CF2)m—(CF2CFX2)n—SO2F??(1) wherein each of X1 and X2 which may be the same or different, is a fluorine atom or a trifluoromethyl group, k is an integer of from 0 to 3, l is 0 or 1, m is an integer of from 0 to 12, and n is an integer of from 0 to 3, [CF3CF2CF2O(CF(CF3)CF2O)pCF(CF3)COO]2??(2) wherein p is an integer of from 0 to 8.

Abstract: To provide an electrolyte material having high electrical conductivity (ion exchange capacity) and a high softening temperature. An electrolyte material comprising a copolymer containing repeating units represented by the following formula (1) and repeating units represented by the following formula (2): wherein RF is a fluorine atom or the like, each of X1 and X2 is a fluorine atom or a trifluoromethyl group, m is from 2 to 4, and Y is a hydroxyl group or the like.

Abstract: It is to provide a process for producing a polymer for an electrolyte material to prepare polymer electrolyte fuel cells which can be operated at a high temperature and with which high output can be obtained, with a stable composition. A process for producing a fluoropolymer by polymerization reaction of tetrafluoroethylene and a fluoromonomer represented by the following formula (m), wherein the polymerization reaction is carried out by continuously charging the reactor with tetrafluoroethylene and the fluoromonomer: wherein m1 is an integer of from 1 to 6.