Lubricant for recording medium and magnetic disk
The present invention provides a lubricant for recording media that does not readily decompose, and which has high adhesion to recording media, and a magnetic disk that is durable against continuous sliding under high-speed rotation. The present invention provides a lubricant for recording media containing: a perfluoropolyether compound represented by Formula (1), R 1 —CH 2 CF 2 O—(CF 2 CF 2 O) m —(CF 2 O) n —CF 2 CH 2 —R 2 (1) wherein R 1 represents R represents a C 1-4 haloalkyl group, R 2 represents —OCH 2 CH(OH)CH 2 OH, and m and n are each independently 1-30; and another perfluoropolyether compound represented by Formula (2), R 1 —CH 2 CF 2 O—(CF 2 CF 2 O) m —(CF 2 O) n —CF 2 CH 2 —R 3 (2) wherein R 1 , m and n are as defined above and R 3 represents —OCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 OH. The present invention also provides a magnetic disk having a lubricating layer essentially consists of such a lubricant.
1. A lubricant for recording media containing:
a perfluoropolyether compound represented by Formula (1),
R 1 —CH 2 CF 2 O—(CF 2 CF 2 O) m —(CF 2 O) n —CF 2 CH 2 —R 2 (1)
wherein R 1 represents
R represents a C 1-4 haloalkyl group, R 2 represents —OCH 2 CH(OH)CH 2 OH, and m and n are each independently 1-30; and
another perfluoropolyether compound represented by Formula (2),
R 1 —CH 2 CF 2 O—(CF 2 CF 2 O) m —(CF 2 O) n —CF 2 CH 2 —R 3 (2)
wherein R 1 , m and n are as defined above and R 3 represents —OCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 OH.
2. A magnetic disk obtained by sequentially forming a recording layer and a protective layer on a support, and forming a lubricating layer essentially consisting of the lubricant of claim 1 on the surface of the protective layer.