Biaxially oriented laminated polyester film and magnetic recording medium having the same as base film
US5556691A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 1994 |
| Grant date | Sep 17, 1996 |
| Priority date | — |
| Expiry date | Jan 26, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A biaxially oriented laminated polyester film comprising a first thin polyester layer containing large-diameter inert particles and small-diameter inert particles; a second polyester layer containing large-diameter inert particles; and a third thin polyester layer containing large-diameter inert particles and small-diameter inert particles, the biaxially oriented laminated polyester film satisfying the following expression (1), ##EQU1## wherein: W.sub.1 is the content (wt. %) of the large-diameter inert particles in the first thin polyester layer, W.sub.2 is the content (wt. %) of the large-diameter inert particles in the second polyester layer, D.sub.13 is a total of the thickness (.mu.m) of the first thin polyester layer and the thickness (.mu.m) of the third thin polyester layer, and D.sub.2 is the thickness (.mu.m) of the second polyester layer. This film is useful as a base film for a magnetic medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.