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:
Dec. 20, 2016
Filed:
Sep. 18, 2012
Nissan Chemical Industries, Ltd., Tokyo, JP;
NISSAN CHEMICAL INDUSTRIES, LTD., Tokyo, JP;
Abstract
A flattening film forming composition for a hard disk that can prevent a magnetic material from migrating to the nonmagnetic layer, including a photopolymerizable coating material containing at least one polymer selected from a homopolymer that has a divinyl aromatic compound-derived unit structure and a copolymer having the unit structure or containing a mixture of the polymer and a photopolymerizable compound. The photopolymerizable compound may include an acrylate group, a methacrylate group, or a vinyl group. The polymer may be a copolymer further containing an addition polymerizable compound as a component to be copolymerized. A method for producing a hard disk, including: a first step of forming projections and recesses on a magnetic body; a second step of coating the projections and recesses with the flattening film forming composition; and a third step of flattening the coating by means of etching and exposing a surface of the magnetic body.