METHOD OF PRODUCING PERFLUOROCARBOXYLIC ACID Russian patent published in 2013 - IPC C07C53/50 C25B3/08 C07C51/00 

FIELD: chemistry.

SUBSTANCE: method of producing perfluorocarboxylic acid involves production of an acid fluoride by electrochemical fluorination of a fluorine-containing alkanol of general formula H(CF₂-CF₂)_nCH₂OH, where n=3-4 in a medium of anhydrous hydrogen fluoride and hydrolysis thereof, wherein the mixture of alkanol with n=3 or n=4 is fluorinated with an ester of carboxylic or perfluorinated carboxylic acid with 2-5 carbon atoms in the chain, taken in amount of 2-50% of the weight of the fluorinated mixture. To obtain perfluoroheptanoic acid, a mixture is formed from alkanol H(CF₂-CF₂)₃CH₂OH with an ester of a carboxylic or perfluorinated carboxylic acid with 2-5 carbons atoms in the chain, taken in amount of 2-50% of the weight of the fluorinated mixture. To obtain perfluorononanoic acid, a mixture of alkanol H(CF₂-CF₂)₄CH₂OH with an ester of a carboxylic or perfluorinated carboxylic acid with 2-5 carbons atoms in the chain, taken in amount of 2-50% of the weight of the fluorinated mixture, is fluorinated.

EFFECT: high output of end products.

9 cl, 3 ex