| abstract |
Fluorinated greases comprising: n(A) from 1% to 50% by weight of a thickener; n(B) from 99% to 50% by weight of a mixture of: n(B1) from 0,1 to 100% by weight of a compound of structure: n n X 1 -O (CF 2 O) n (CF 2 CF 2 O) m (CF 2 CF 2 CF 2 O) p (CF 2 CF 2 CF 2 CF 2 O) q -X 2 (I) n nwherein: nX 1 , X 2 have formula -(CF 2 ) z CF 3 wherein z is an integer between 0 and 3; n is an integer between 1 and 200; m is an integer between 0 and 200; p, q are integers between 0 and 10; with the proviso that: nthe (p+q)/(p+q+m+n) ≤0.05; m/n ≤0.7; the number average molecular weight of (I) is between 1,000 and 10,000; the kinematic viscosity at 40°C is lower than 20 cSt; and n n(B2) from 99.9% to 0% by weight of a perfluoropolyether oil having a kinematic viscosity at 40°C higher than 15 cSt and comprising repeating units of the type (CFXO) wherein X is F or CF 3 ; -CF 2 CF 2 O-, -C 3 F 6 O, -CF(CF 3 )CF 2 O-, -CF 2 CF(CF 3 )O-, statistically distributed along the chain. |