Perfluoropolyether compound, lubricant and magnetic disk

Patent metadata

Field	Value
Publication number	US-12110470-B2
Application number	US-202017620930-A
Country	US
Kind code	B2
Filing date	Jun 15, 2020
Priority date	Jul 3, 2019
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

Provided are a magnetic disk and, in particular, a compound which makes it possible to realize a lubricant having excellent heat resistance and solubility in a fluorine-based solvent. A perfluoropolyether compound in accordance with an aspect of the present invention has, in hydrocarbon groups at both terminals thereof, five or six hydroxyl groups in total.

First claim

The invention claimed is:

1. A lubricant comprising:
a perfluoropolyether compound represented by the following formula (1):
R 1 —CH 2 —R 2 —CH 2 —R 3   (1)

wherein: R 1 is HOCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 O—;
R 2 is —(CF 2 ) x O(CF 2 CF 2 CF 2 O) m (CF 2 ) x —, wherein x is a real number of 1 to 3, m is a real number of 1 to 15; and
R 3 is —OCH 2 CH(OH)CH 2 OH or —OCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 OH,
wherein at a temperature of 550° C., from heating at a rate of temperature rise of 2° C./min under a nitrogen atmosphere, the lubricant exhibits a 50% weight reduction temperature of higher than 280° C.

2. A magnetic disk comprising:
a recording layer;
a protective layer disposed on the recording layer; and
a lubricant layer disposed on the protective layer,
the lubricant layer containing a perfluoropolyether compound represented by the following formula (1):
R 1 —CH 2 —R 2 —CH 2 —R 3   (1)

wherein: R 1 is HOCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 O—;
R 2 is —(CF 2 ) x O(CF 2 CF 2 CF 2 O) m (CF 2 ) x —, wherein x is a real number of 1 to 3, m is a real number of 1 to 15; and
R 3 is —OCH 2 CH(OH)CH 2 OH or —OCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 OH.

3. A lubricant composition comprising: a fluorine-based solvent and a perfluoropolyether compound represented by the following formula (1):
R 1 —CH 2 —R 2 —CH 2 —R 3   (1)

wherein: R 1 is HOCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 O—;
R 2 is —(CF 2 ) x O(CF 2 CF 2 CF 2 O) m (CF 2 ) x —, wherein x is a real number of 1 to 3, m is a real number of 1 to 15; and
R 3 is —OCH 2 CH(OH)CH 2 OH or —OCH 2 CH(OH)CH 2 OCH 2 CH(OH)CH 2 OH.

4. The lubricant composition of claim 3 , wherein at a temperature of 550° C., from heating at a rate of temperature rise of 2° C./min under a nitrogen atmosphere, the perfluoropolyether compound exhibits a 50% weight reduction temperature of higher than 280° C.

5. A magnetic disk comprising:
a recording layer;
a protective layer disposed on the recording layer; and
a lubricant layer disposed on the protective layer, the lubricant layer containing the lubricant composition recited in claim 3 .

Assignees

• Moresco Corp

Inventors

• Hatta Tomomi
• Shimizu Tsuyoshi

Classifications

• C10N2040/18

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

• C10M2213/06

  Perfluoro polymers · CPC title

• G11B5/7257

  Perfluoropolyether lubricant · CPC title

• C10N2020/085

  Non-volatile compounds · CPC title

• C10N2030/74

  Noack Volatility · CPC title