Biaxially oriented laminated polyester film
US5529832A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1994 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Nov 10, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31797
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A biaxially oriented laminated polyester film comprising a first polyester surface layer having (a1) a central line average roughness R.sub.aA of 1 to 7.9 nm, (b1) a 10-points average roughness R.sub.ZA of 15 to 400 nm and (c1) an R.sub.ZA /R.sub.aA ratio of 11-51, and a second polyester surface layer having (a2) a central line average roughness R.sub.aB which is greater than R.sub.aA and is 5 to 40 nm, (b2) a 10-points average roughness R.sub.ZB of 75 to 600 nm and (c2) an R.sub.ZB /R.sub.aB ratio of 20 or less, and satisfying the relationship between the first polyester surface layer and the second polyester surface layer, which is represented by the following expressions, EQU R.sub.aA .times.R.sub.aB <50 (1) EQU R.sub.ZA .times.R.sub.ZB =130 to 3,000 (2). This biaxially oriented laminated polyester film is excellent in lubricity, high-speed take-up properties, processability and electromagnetic characteristics when used for a magnetic film, and is particularly useful as a base film for a magnetic recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.