Biaxially oriented wholly aromatic polyester film
US4333907A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1980 |
| Grant date | Jun 8, 1982 |
| Priority date | — |
| Expiry date | Jun 24, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2367/02
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A melt-molded film of a wholly aromatic polyester, said film having in its plane two perpendicularly crossing directions in each of which the Young's modulus and strength of the film at 25.degree. C. are at least about 200 kg/mm.sup.2 and at least about 5 kg/mm.sup.2 respectively, the product of the Young's moduli of the film in the two directions being at least 8.times.10.sup.4 (kg/mm.sup.2).sup.2, and said wholly aromatic polyester being substantially linear, having a melt viscosity at about its melting point of at least about 10000 poises, and being composed substantially of recurring units derived from p-hydroxybenzoic acid, recurring units derived from a m- or p-oriented aromatic dicarboxylic acid and recurring units derived from a m- or p-oriented aromatic dihydroxy compound, the proportion of said recurring units derived from p-hydroxybenzoic acid being about 30 to about 70 mole % based on the entire recurring units. This invention provides also a process for producing said film which comprises heating aforesaid wholly aromatic polyester to a temperature above a point at which the polyester is extrusion-moldable and extruding the heated polyester through a slit; and either (…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.