Polyester film
US4965307A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1988 |
| Grant date | Oct 23, 1990 |
| Priority date | — |
| Expiry date | Dec 7, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2367/02
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Polyester films with a good slitting property and good slipping property contain, in first and second embodiments, at least 0.005% by weight of calcium carbonate particles. The particle size S.sub.c of the polyester crystals, crystal face orientation index X.sub.i and the difference .DELTA.n between the refractive indices in the machine direction and in the transverse direction of the polyester film have a specific relationship, or the internal haze H, face orientation coefficient f.sub.n or the difference .DELTA.n between the refractive indices in the machine direction and in the transverse direction have a specific relationship. By satisfying the specific relationship, a good slitting property and good slipping property are obtained. A third embodiment provides a polyester film containing at least 0.005% by weight of calcium carbonate particles, which has a specific center line average roughness Ra, face orientation coefficient f.sub.n, the difference .DELTA.n between the refractive indices in the machine direction and in the transverse direction, and F-5 value in the transverse direction. By these characteristics, a good slitting property, good slipping property and good shaving…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.