Process of producing magnetic recording media
US4548682A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1984 |
| Grant date | Oct 22, 1985 |
| Priority date | — |
| Expiry date | Jun 8, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S205/917
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium having excellent magnetic properties and a uniform recording envelope suitable for, in particular, high-density recording is obtained by packing a magnetic substance in the micro pores of anodic oxide film formed on an aluminum substrate by subjecting the same to an anodic oxidation treatment to produce an anodic oxide film having a thickness of at least 4 .mu.m. The recording medium can be improved by immersing the anodized aluminum substrate in an acid or alkali bath to chemically dissolve a part of the anodic oxide film, and thereby enlarge the micro pores in the anodic oxide film to a pore diameter in the range of 300 .ANG. to 1,400 .ANG., optionally applying an electric current to the aluminum substrate in the immersion bath if necessary to control the thickness of the barrier layer in the anodic oxide film, before subjecting the treated substrate to an electrolytic treatment in a bath containing ions of a magnetic substance to deposit the magnetic substance in the enlarged micro pores. Thereafter, the surface of the anodic oxide film, and any excess deposited magnetic material thereon, is physically ground to expose the packed magnetic substance at…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.