Process for making oriented semicrystalline polyester films
US5409657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1992 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | Oct 26, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2367/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed are semicrystalline polyester oriented films having the properties of MD F5.gtoreq.18 daN/mm.sup.2, TD F5.gtoreq.10 daN/mm.sup.2, MDE.gtoreq.800 daN/mm.sup.2, TDE.gtoreq.400 daN/mm.sup.2, MDE+TDE.gtoreq.1200 daN/mm.sup.2, MDS 105.ltoreq.1.5%, MDS 150.ltoreq.5.2%, and TD St/TD F5.ltoreq.2.2. Also disclosed is a process for preparing semicrystalline polyester oriented films wherein an amorphous polyester film is successively subjected to a sequence of drawings comprising a lengthwise drawing in a single stage, a transverse drawing and a lengthwise drawing, wherein the first drawing mD is conducted at a temperature of between Tg +40.degree. C. and Tc -20.degree. C. and with a draw ratio .lambda.mD of between 1.2 and 3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.