Flattening film forming composition for hard disk
US9523020B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2012 |
| Grant date | Dec 20, 2016 |
| Priority date | — |
| Expiry date | Nov 4, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F230/085
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.