Polyester film for magnetic recording medium, and magnetic recording tape
US6468627B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2000 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Apr 16, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Disclosed is a base film that has excellent electromagnetic conversion property over the entire length from a roll core portion to a surface portion of the film product and that is suitable for the production of digital videotapes with reduced dropouts. A polyester film for a magnetic recording medium includes at least a polyester layer A and a polyester layer B laminated. A center-line surface average roughness (SRa value) of a layer A-side surface of the film is 2 nm to 4 nm, and a ten-point average surface roughness (SRz value) of the layer A-side surface is 10 nm to 40 nm. The layer B contains a fine particle &agr; whose average particle size is at least 50 nm and less than 250 nm, and a fine particle &bgr; whose average particle size is at least 250 nm and less than 500 nm. The content of the fine particle &agr; in the layer B is 0.1 wt. % to 1.0 wt. %. The content of the fine particle &bgr; in the layer B is 0.01 wt. % to 0.10 wt. %. A magnetic recording tape is formed by providing a ferromagnetic metal thin film on a layer A-side surface of the polyester film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.