Patent ID: 6919479

Claim:
A process for the preparation of perfluoropolyethers having at least one —COF end group of formula: T-CFX′—O—R f —CFX—COF (I) wherein: T is equal to COF, F, or C 1 -C 3 perfluoroalkyl; X and X′ are equal to or different from each other and are F or —CF 3 ; R f is selected from: —(C 2 F 4 O) m (CF 2 CF(CF 3 )O) n (CF 2 O) p (CF(CF 3 )O) q — wherein: the sum n+m+p+q ranges from 2 to 200, the (p+q)/(m+n+p+q) ratio is lower than or equal to 10:100, the n/m ratio ranges from 0.2 to 6; m, n, p, and q are equal to or different from each other and when m and n range from 1 to 100 then p and q range from 0 to 80; the units with n, m, p, q indexes being randomly distributed along the chain, —(CF 2 CF 2 CF 2 O) r — wherein r ranges from 2 to 200, —(CF(CF 3 )CF 2 O) s — wherein s ranges from 2 to 200, by reduction of the corresponding perfluoropolyethers containing peroxidic bonds, using gaseous hydrogen in the presence of a catalyst comprising metals of the VIII group supported on metal fluorides, optionally in the presence of perfluorinated solvents, inert at a temperature from 20° C. to 140° C. and at a pressure between 1 and 50 atm.