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:
Jun. 18, 1991
Filed:
Nov. 13, 1989
Rohitkumar H Vora, Westfield, NJ (US);
Paul N Chen, Sr, Gillette, NJ (US);
Hoechst Celanese Corp., Somerville, NJ (US);
Abstract
Copolyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine, at least one other diamine, and pyromellitic dianhydride can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride, 3,3'4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.) and have superior electrical properties, for example, dielectric constant of less than about 2.5 at 10 megahertz.