Biaxially oriented polyester film for magnetic recording media
US5270096A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1991 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Apr 18, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A biaxially oriented polyester film for magnetic recording media improved in slipperiness, shaving resistance and scratch resistance by protrusions formed on the film surface, namely, a polyester film for magnetic recording media wherein the film is a biaxially oriented polyester film which contains (I) heat resistant high molecular particles having an average particle size of 0.3 to 1.5 .mu.m in 0.001 to 0.5% by weight of the polyester, and PA1 (II) alumina particles having an independent existence rate of 80% or more and an average particle size of 0.06 to 0.2 .mu.m in 0.05 to 1.0% by weight of the polyester and/or colloidal silica particles having an independent existence rate of 80% or more and an average particle size of 0.3 .mu.m or less in 0.05 to 2.0% by weight of the polyester; wherein the distribution curve, in the range where the height (x : .mu.m) is 0.05 .mu.m or more and the number of the protrusions (y : per mm.sup.2) is 30 protrusions/mm.sup.2 or more, of protrusions formed on the film surface satisfies the following formula A EQU -11.4x+4<log y<-10.0x+5 A wherein x is the height (.mu.m) from the standard level and Y is the number of protrusions (per mm.sup.2) count…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.