METHOD OF PRODUCING PERFLUOROCARBOXYLIC ACIDS Russian patent published in 2009 - IPC C07C53/21 C07C51/00 C25B3/08 

FIELD: chemistry.

SUBSTANCE: present invention pertains to the method of obtaining perfluorocarboxylic acids, which, like their derivatives, are used for polymerisation of perfluoro olefins, for producing perfluorinated surface active substances with high surface activity, as well as water and oil proofing agents for processing fabrics, paper and leather. The method of producing perfluorocarboxylic acids involves electrochemical fluorination in hydrogen fluoride of telomeric alkanols with general formula H(CF₂CF₂)_nCH₂OH, where n=3 and 4. The obtained perfluoroanhydrides subsequently undergo hydrolysis. Electrochemical fluorination of telomeric alkanols takes place in the presence of an aliphatic or aromatic amine as an electrolytic additive. Hydrolysis is achieved using water, adding it directly into the reaction crude mixture, obtained after electrochemical fluorination.

EFFECT: simplification of the process and increased output of target perfluorocarboxylic acids with high degree of purity.

3 cl, 3 ex