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:
Nov. 03, 2015
Filed:
Sep. 30, 2009
Koichi Shimokawa, Shinjuku-ku, JP;
Katsushi Hamakubo, Shinjuku-ku, JP;
Kae Itoh, Shinjuku-ku, JP;
Abstract
A magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. The lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.2. The two types of compounds include a compound a having a hydroxyl group at the end and a compound b having a number average molecular weight smaller than the number average molecular weight of the compound a and not more than 1500. A content of the compound b in the two types of compounds is not more than 10%.