Biaxially drawn, composite polyester film substrates
US4615939A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1984 |
| Grant date | Oct 7, 1986 |
| Priority date | — |
| Expiry date | Jul 13, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/269
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Biaxially drawn, advantageously filled multilayer polyester film substrates, well adapted for the manufacture of magnetic recording tapes, are comprised of a composite of at least two adjacent layers of biaxially stretched thermoplastic polyester film, at least one of the face surfaces thereof having a roughness defined by a plurality of dome and peak protuberances extending therefrom, said domes being present in a concentration of at least 5 per mm.sup.2 and having heights of at least 9/100 of one micron, the ratio of the height of such dome protuberances to the diameter of the base thereof being less than 1/100, and the ratio of the height of such peak protuberances to the diameter of the base thereof being at least 1/100.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.