Patent ID: 7510999

Claim:
A lubricant composition for use as a lubricant for magnetic recording media, comprising a first liquid lubricant and a second liquid lubricant, wherein the first liquid lubricant contains a cyclotriphosphazene ring attached to at least one perfluoropolyether having a single terminal hydroxyl group and has the structure of formula (I) wherein, x is an integer from 1 to 5, p is an integer from 5 to 36 and q is an integer from 4 to 30 and, wherein the second liquid lubricant contains a perfluoropolyether selected from compounds having the structure of formula (IIa), formula (IIb), and combinations thereof, wherein formulae (IIa) and (IIb) have the structures Râ€”[CH 2 ] r â€”[CF 2 O] s â€”[CF 2 CF 2 O] t â€”[CF 2 O] u â€”CF 2 â€”[CH 2 ] v â€”R 1 (IIa) R 1 RNâ€”[CH 2 ] r â€”[CF 2 O] s â€”[CF 2 CF 2 O] t â€”[CF 2 O] u â€”CF 2 â€”[CH 2 ] v â€”NRR 1 (IIb) in which r, s, t, u and v are independently zero or an integer, with the proviso that s, t and u are not all zero, wherein when the second lubricant contains a perfluoropolyether having a structure of formula (IIa) R and R 1 are independently selected from â€”CH 2 CH 2 OH, and â€”CH 2 CH 2 CH 3 ; and wherein when the second lubricant contains a perfluoropolyether having a structure of formula (IIb) R and R 1 are independently selected from â€”CH 2 CH 2 OH, and â€”CH 2 CH 2 CH 3 ; wherein y is an integer from 1 to 6.