Light-weight polyester film and process for its production
US5204418A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1992 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | Jan 30, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2367/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A light-weight polyester film which comprises (A) from 50 to 95% by weight of a crystalline polyester resin and (B) from 5 to 50% by weight of a maleimide copolymer, said maleimide copolymer being dispersed in the film in the form of particles having diameters of from 0.1 to 20 .mu.m and fine voids being present in the film, and which has an apparent specific gravity of from 0.3 to 1.1, wherein said maleimide copolymer comprises from 30 to 50 mol % of a maleimide monomer group, from 30 to 70 mol % of an aromatic vinyl monomer group, from 0 to 40 mol % of an unsaturated dicarboxylic anhydride monomer group and from 0 to 40 mol % of other copolymerizable monomer group, and said maleimide copolymer has a glass transition temperature higher by at least 10.degree. C. than the crystalline polyester resin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.