Abstract: In a magnetic disk having a magnetic layer, a protection layer, and a lubrication layer formed on a substrate in this order, a surface free energy ?S of a surface of the magnetic disk derived by an extended Fowkes equation is greater than 0 and no greater than 24 mN/m. ?Sd (dispersion force component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 17 mN/m, ?Sp (dipole component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 1 mN/m, and ?Sh (hydrogen bonding force component of surface free energy) forming the surface free energy ?S is greater than 0 and no greater than 6 mN/m.
Abstract: A system and associated methods are described for preparing a magnetic disk for installation within a disk drive system. For example, a polyfunctional lubricant may be mixed with a chemical agent to esterify the polyfunctional lubricant and cap hydroxyl groups of the polyfunctional lubricant. The magnetic disk may then be dip coated with the polyfunctional lubricant and chemical agent mixture. A polishing system then polishes the magnetic disk via an abrasive polishing tape after dip coating the magnetic disk. A portion of the chemical agent is then removed from the magnetic disk to bond a portion of the lubricant to the magnetic disk to prevent the lubricant from interfering with a read/write head when installed within a disk drive system.
Type:
Grant
Filed:
April 20, 2009
Date of Patent:
April 2, 2013
Assignee:
HGST Netherlands, B.V.
Inventors:
Charles A. Brown, John M. Burns, Xing-Cai Guo, Thomas E. Karis, Bruno Marchon
Abstract: A lubricant composition is provided comprising a first liquid lubricant and a second liquid lubricant, wherein the first liquid lubricant contains a cyclotriphosphazene ring attached to at least one perfluoropolyether having a single terminal hydroxyl group, and the second liquid lubricant contains a perfluoropolyether having two end groups selected from hydroxyl, tertiary amine, and combinations thereof. A magnetic recording media is also provided, comprising a substrate, a magnetic layer, an overcoat layer and a lubricant layer thereon, wherein the lubricant layer is formed from the lubricant composition. A further aspect of the invention concerns a method of making a magnetic recording media comprising forming a magnetic layer on a substrate; forming a protective overcoat layer on the magnetic layer; and forming a lubricant layer on the surface of the overcoat layer by applying the lubricant composition to the surface of the overcoat layer.
Type:
Grant
Filed:
May 28, 2004
Date of Patent:
March 31, 2009
Assignee:
Hitachi Global Storage Technologies Netherlands B.V.
Abstract: The present invention provides a lubricant capable of holding an excellent lubricating property under various types of service conditions, maintaining a lubricating effect for a long period of time and providing excellent traveling property, abrasion resistance, durability and the like, a recording medium using the lubricant and a carboxylic acid type compound constituting the lubricant.