| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing a fluorine-containing elastomer to be suitably used as a fuel system component molding material.SOLUTION: In a method of producing a fluorine-containing elastomer, after feeding a feed monomer mixture, which consists of TFE, VdF and HFP and is an equivalent for 10-40 wt% of the total amount of the whole monomer mixture, to a reaction system and starting a copolymerization reaction in the presence of CFCFCFOCF (CF)CFOCF(CF)COONH, a residual of the monomer mixture is additionally fed for producing the fluorine-containing elastomer. As a first step of separate addition, the monomer mixture in an amount of 30-70 wt% of the total mount of the monomer mixture to be separately added is separately added in the presence of a chain transfer agent used in a ratio of 0.0001-0.1 wt% for the total amount of a reaction raw material in the feeding step. Consequently, in the additional presence of the chain transfer agent used in a ratio of 0.3-1.5 wt% for the total amount of the reaction raw material until this step, the monomer mixture in amount of 70-30 wt% of the total amount of the monomer mixture to be separately added is separately added, as a second step of separate addition, to the same reaction system for performing the copolymerization reaction. |
