Lubricant compound for magnetic disk and magnetic disk
View Patent ↗A lubricant compound is contained in a lubrication layer of a magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, and the lubricant compound contains a component A represented by Chemical formula 1 and a component B represented by Chemical formula 2: wherein X in Chemical formula 1 represents OH wherein X in Chemical formula 2 represents OCH 2 CH(OH)CH 2 OH, and the lubricant compound further contains a component C made of a specific compound having a phosphezene ring in the structure thereof.
1. A lubricant compound for a magnetic disk contained in a lubrication layer of a magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, characterized in that
the lubricant compound contains a component A represented by Chemical formula 1 and a component B represented by Chemical formula 2:
wherein X in Chemical formula 1 represents OH
wherein X in Chemical formula 2 represents OCH 2 CH(OH)CH 2 OH,
and the lubricant compound further contains at least one type of a component C, wherein the component C is selected from compounds C-1 and C-2 represented by the following formulae:
wherein Rf represents —(OC 2 F 4 )m(OCF 2 )n-, and m and n each represents an integer of not less than 1, and
PN is represented from one of the following formulae:
wherein x and y each is an integer of 5 when C is compound (C-1) and an integer of 4 when C is compound (C-2),
wherein the lubricant compound does not contain a component D represented by the following Chemical formula
2. The lubricant compound for a magnetic disk according to claim 1 , wherein in the lubricant compound, the ratio of the component C among the component A, the component B, and the component C is 5 to 20 weight %.
3. A magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, characterized in that
the lubrication layer contains the lubricant compound according to claim 1 .
4. The magnetic disk according to claim 3 , wherein
the protective layer is a carbon protective layer formed by a plasma CVD method.
5. The magnetic disk according to claim 3 , wherein
the magnetic disk is mounted on a magnetic disk device whose start/stop mechanism is a load-unload type and used under the head floating amount of 5 nm or less.
6. The magnetic disk according to claim 3 , wherein a thickness of the lubrication layer is 10 to 13 Å.
7. The lubricant compound for a magnetic disk according to claim 1 , wherein a weight ratio between the components A and B is between 1:3 and 1:10.