Patent ID: 7186787

Claim:
A process for lubricating in the presence of metals, comprising the step of applying linear perfluoropolyethers as lubricants, where said linear perfluoropolyethers have the following structural formula: T-O(CF 2 O) n (CF 2 CF 2 O) m (CF 2 CF 2 CF 2 O) r (CF 2 CF 2 CF 2 CF 2 O) s -T 1 (I) wherein: T and T 1 are the same or different, and are each selected from the group consisting of CF 3- , CF 3 CF 2- , C 3 F 7- , C 4 F 9- , CICF 2- , or CICF 2 CF 2- ; n, m, r, s are integers such that the number average molecular weight is comprised between 700 and 100,000: the m/n ratio is comprised between 2 and 20; the (r+s)/(n+m+r+s) ratio is comprised between 0.05 and 0.2; the n/(n+m+r+s) ratio ranges from 0.05 to 0.40; and wherein the perfluorooxyalkylene units are statistically distributed along the polymeric chain.