Polyester film for magnetic recording tape
US4840830A · kind A · utility
6Cited by
7References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1987 |
| Grant date | Jun 20, 1989 |
| Priority date | — |
| Expiry date | Oct 6, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polyester film suitable for use as the magnetic tape base for video recording, capable of high density recording and having stable slidability or running characteristics. The polyester film is made of a polyester which contains 0.05-1 wt % particles containing calcium and phosphorus and of which the number n of the second interference fringes (number/mm.sup.2) and the average centerline roughness (.mu.m) satisfy the following relationships: EQU n<30 (1) EQU 0.005.ltoreq.R.sub.a .ltoreq.0.025 (2)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.