Lubricant for magnetic recording medium, and magnetic recording medium

Patent metadata

Field	Value
Publication number	US-10141017-B2
Application number	US-201615548335-A
Country	US
Kind code	B2
Filing date	Feb 3, 2016
Priority date	Feb 6, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A lubricant for a magnetic recording medium including an ionic liquid including a Bronsted acid and a Bronsted base that is primary amine as constituents of the ionic liquid, wherein the Bronsted acid includes a fluorine-containing chain, the Bronsted base includes a fluorine-containing chain that is a perfluoroalkyl chain or a perfluoropolyether chain, wherein the fluorine-containing chain in the Bronsted acid is a perfluoropolyether chain or the fluorine-containing chain in the Bronsted base is the perfluoropolyether chain, or the fluorine-containing chain in the Bronsted acid is the perfluoropolyether chain and the fluorine-containing chain in the Bronsted base is the perfluoropolyether chain, and a number average molecular weight of the fluorine-containing chain in the Bronsted acid is 1,500 or less.

First claim

The invention claimed is:

1. A lubricant for a magnetic recording medium, comprising:
an ionic liquid including a Bronsted acid and a Bronsted base that is primary amine as constituents of the ionic liquid,
wherein the Bronsted acid includes a fluorine-containing chain,
wherein the Bronsted base includes a fluorine-containing chain that is a perfluoroalkyl chain or a perfluoropolyether chain,
wherein the fluorine-containing chain in the Bronsted acid is a perfluoropolyether chain or the fluorine-containing chain in the Bronsted base is the perfluoropolyether chain, or the fluorine-containing chain in the Bronsted acid is the perfluoropolyether chain and the fluorine-containing chain in the Bronsted base is the perfluoropolyether chain, and
wherein a number average molecular weight of the fluorine-containing chain in the Bronsted acid is 1,500 or less.

2. The lubricant for a magnetic recording medium according to claim 1 ,
wherein the number average molecular weight of the fluorine-containing chain in the Bronsted acid is 500 or less.

3. The lubricant for a magnetic recording medium according to claim 1 ,
wherein the Bronsted acid is sulfonic acid including the fluorine-containing chain or sulfonyl imide including the fluorine-containing chain, and
wherein the Bronsted base is primary amine including the perfluoropolyether chain.

4. The lubricant for a magnetic recording medium according to claim 1 ,
wherein a coefficient of dynamic friction of the lubricant is 0.30 or less.

5. A magnetic recording medium comprising:
a non-magnetic support;
a magnetic layer on or above the non-magnetic support; and
the lubricant for a magnetic recording medium according to claim 1 , on or above the magnetic layer.

Assignees

• Dexerials Corp

Inventors

• Tano Nobuo
• Hatsuda Kouki
• Kondo Hirofumi

Classifications

• C10M2215/0425

  used as base material · CPC title

• C10M171/00 Primary

  Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated (chemically defined ingredients C10M101/00 - C10M169/00; petroleum fractions C10M101/02, C10M121/02, C10M159/04) · CPC title

• C10M105/60

  having amino groups bound to an acyclic or cycloaliphatic carbon atom · CPC title

• C10N2040/18

  in connection with recordings on magnetic tape or disc · CPC title

• C10N2050/02

  dissolved or suspended in a carrier which subsequently evaporates to leave a lubricant coating · CPC title