The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 20, 1993
Filed:
Jan. 30, 1992
Kenji Yasue, Uji, JP;
Eiji Y Yamamoto, Uji, JP;
Katsuyuki Toma, Uji, JP;
Minoru Kishida, Uji, JP;
Yoshiaki Kozuka, Uji, JP;
Unitika Ltd., Amagasaki, JP;
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.