PERFLUORCARBOXYLIC ACID FLUORIDE PROCESS Russian patent published in 2009 - IPC C25B3/08 C07C53/50 C07C51/00 

FIELD: chemistry.

SUBSTANCE: perfluorcarboxylic acids and their derivatives are characterised by very high heat resistance and chemical stability, and are used in perfluorolefin polymerisation to produce perfluorochemical surface-active substances. Process for perfluorcarboxylic acid fluorides including perfluorheptanoic and perfluornonanoic acid fluorides, consists in electrochemical fluoridation of fluorine-containing alkanols of general formula H(CF₂-CF₂)_nCH₂OH, where n=3-4 in anhydrous hydrogen fluoride medium. Said alkanols are fractionated with each unit fraction fluoridated with tertiary aliphatic or aromatic amine added as an electrolytic additive in amount 5-10 wt % of electrolyte weight.

EFFECT: high yield perfluorheptanoic and perfluornonanoic acid fluorides without any changes in process parametres on the basis of fluorine-containing alkanols that are industrial products of methanol and tetrafluorethylene telomerisation.

3 cl, 1 tbl, 6 ex