The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 15, 2012
Filed:
Sep. 28, 2007
Katsushi Hamakubo, Tokyo, JP;
Koichi Shimokawa, Tokyo, JP;
Kota Suzuki, Tokyo, JP;
WD Media (Singapore) Pte. Ltd., Singapore, SG;
Abstract
A lubricant for magnetic disks which can form a lubricating layer having a reduced thickness while attaining a high coverage and is excellent in heat resistance and adhesion to a protective layer. The lubricant for magnetic disks comprises a perfluoropolyether compound in which the relationship between the number-average molecular weight and the standardized value of the number of hydroxy groups contained in the molecule satisfies the following: the number-average molecular weight is in the range of 1,000-6,000; the standardized value of the number of hydroxy groups contained in the molecule is 180 or higher; and the compound is in a region located below the line connecting the point where the number-average molecular weight is 1,000 and the standardized value of the number of hydroxy groups in the molecule is 400 to the point where the number-average molecular weight is 6,000 and the standardized value of the number of hydroxy groups in the molecule is 1,600. The compound has at least one hydroxy group around the center of the molecular chain.