Perfluoropolyether ester compound, lubricant and magnetic recording medium
View Patent ↗A novel perfluoropolyether derivative, which has at least one ester bond and is useful as a lubricant with a decomposition temperature of 300° C. or more, is obtained by an esterification reaction between a perfluoropolyether diol having hydroxyl groups at both ends thereof and represented by the formula (1) and a perfluoropolyether dicarboxylic acid having carboxyl groups at both ends thereof and represented by the formula (2): HOCH 2 —R—CH 2 OH (1) HOOC—R′—COOH (2) wherein each of R and R′ is a perfluoroether group.
1. A perfluoropolyether ester compound having at least one ester bond, which is obtained by an esterification reaction between a perfluoropolyether diol having hydroxyl groups at both ends thereof and represented by the formula (1) and a perfluoropolyether dicarboxylic acid having carboxyl groups at both ends thereof and represented by the formula (2):
HOCH 2 —R—CH 2 OH (1)
HOOC—R′—COOH (2)
wherein each of R and R′ is a group selected independently from the following perfluoroether groups R 1 through R 4 :
R 1 : —CF 2 —(OCF 2 CF 2 ) m —(OCF 2 ) n —OCF 2 —
R 2 : —(CF 2 O) j —(CF 2 CF 2 O) k —(CF 2 O) 1 —CF 2 —
R 3 : —(CF 2 CF 2 CF 2 O) o —CF 2 CF 2 —
R 4 : —(CF 2 CF(CF 3 )O) p —CF 2 —
wherein m, n, j, k, l, o and p independently represent integers between 1 and 100.
2. The perfluoropolyether ester compound according to claim 1 , wherein said esterification reaction is performed by the bulk polymerization method.
3. The perfluoropolyether ester compound according to claim 1 , wherein the weight average molecular weights of the perfluoropolyether diol of formula (1) and the perfluoropolyether dicarboxylic acid of formula (2) are each between 2000 and 4000.
4. A lubricant containing the perfluoropolyether ester compound according to claim 1 .
5. A magnetic recording medium having at least a magnetic layer formed on a non-magnetic support, wherein an applied film of the lubricant according to claim 4 is formed on the surface of the magnetic layer.
6. The perfluoropolyether ester compound according to claim 2 , wherein the weight average molecular weights of the perfluoropolyether diol of formula (1) and the perfluoropolyether dicarboxylic acid of formula (2) are each between 2000 and 4000.
7. A lubricant containing the perfluoropolyether ester compound according to claim 2 .
8. A lubricant containing the perfluoropolyether ester compound according to claim 3 .