Advanced lubricant for thin film storage medium

• US 7,371,474 B1
• Filed: 08/06/2004
• Issued: 05/13/2008
• Est. Priority Date: 08/06/2004
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Liu, Jianwei, Stirniman, Michael Joseph
• Primary Examiner(s): Bernatz; Kevin M.
• Application Number:
  US10/912,561
• Time in Patent Office: 1,376 Days
• Field of Search: None
• US Class Current: 428/833.3
• CPC Class Codes: C10M 107/48 containing phosphorus
• CPC Class Codes: C10M 2213/0606 used as base material
• CPC Class Codes: C10M 2225/0405 used as base material
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2040/18 in connection with recordings on magnetic tape or disc
• CPC Class Codes: C10N 2050/023 Multi-layer lubricant coatings
• CPC Class Codes: C10N 2060/12 by phosphorus or a compound containing phosphorus, e.g. PxSy
• CPC Class Codes: C10N 2070/00 Specific manufacturing methods for lubricant compositions

Abstract

A magnetic recording medium comprising a lubricant film comprising a photosynthesized lubricant having a single phase composition of at least a lubricant moiety and an additive moiety is disclosed.

Claims

1. A magnetic recording medium comprising a carbon overcoat and a lubricant film comprising a photosynthesized lubricant that is photosynthesized prior to being applied on the carbon overcoat and having a single phase composition of at least a lubricant moiety that is chemically linked to an additive moiety, further wherein a molecule of the photosynthesized lubricant comprises a main-chain of one or more perfluoropolyether (PFPE) moieties, with one end of the molecule having a pentaphenoxy cyclotriphosphazene, wherein the lubricant film is located directly on the carbon overcoat.

2. The magnetic recording medium of claim 1, wherein the other end of the molecule has a chemical group selected from the group consisting of a single hydroxyl, a multiple hydroxyl, an amide, and combinations thereof.

3. The magnetic recording medium of claim 1, wherein the one or more PFPE moieties comprises:

X—

CF₂—

[(OCF₂—

CF₂)_m—

(OCF₂)_n]—

OCF₂—

X, wherein

X is CH₂OCH₂CYHCH₂—

OH, and Y is —

OH.

4. The magnetic recording medium of claim 1, wherein the molecule has an FTIR spectrum showing that the molecule comprises cyclophosphazene and PFPE moieties.

5. The magnetic recording medium of claim 4, wherein the cyclophosphazene moieties comprise Bis(4-fluorophenoxy)-tetrakis(3-trifluoromethyl phenoxy) cyclotriphosphazene.

6. The magnetic recording medium of claim 1, wherein the molecule has a GPC spectrum showing only one peak.

7. The magnetic recording medium of claim 1, wherein the lubricant film exhibits substantially no phase separation after being exposed for 4 days in air at 80°

C. and under 80 percent RH.

8. The magnetic recording medium of claim 1, wherein the lubricant film comprises a single layer.