| 摘要 |
PROBLEM TO BE SOLVED: To provide fluorinated lubricants having the good resistance to Lewis acids and the thermooxidation combined with a viscosity index higher than 300 and a high molecular weight. SOLUTION: (Per)fluoropolyethers have a formula: HS-(Y-R'f-Y'-S-Y-Rf-Y'S)<SB>n</SB>-H (1), wherein Rf and R'f chains are perfluoropolyoxyalkylenen chains, are equal to or different from each other, are formed of one or more repeating units, are statistically distributed along the chain, Rf and R' having a number of average molecular weight in the range of 500-10,000, preferably 800-3,000; Y and Y' may be equal or different, are selected from -CF<SB>2</SB>CH<SB>2</SB>-, -CF(CF<SB>3</SB>)CH<SB>2</SB>-, -CFXCH<SB>2</SB>(OCH<SB>2</SB>CH<SB>2</SB>)<SB>z</SB>-, wherein z ranges from 1-4 and X=F, CF<SB>3</SB>; -CF<SB>2</SB>CH<SB>2</SB>O(CH<SB>2</SB>)<SB>3</SB>-, -CF(CF<SB>3</SB>)CH<SB>2</SB>O(CH<SB>2</SB>)<SB>3</SB>-; n is a positive integer higher than or equal to 1 selected so as to have a number-average molecular weight of the compound (1) in the range 3,000-50,000; and their use as lubricants in the presence of Lewis acids. COPYRIGHT: (C)2007,JPO&INPIT |
