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. 08, 2004
Filed:
Sep. 11, 2001
Katsunori Yabuta, Otsu, JP;
Kiyokazu Akahori, Otsu, JP;
Kaneka Corporation, , JP;
Abstract
There is provided a process for preparing a polyimide film by a method of casting a film, wherein bubble inclusion and unevenness in thickness are prevented without decrease in mechanical strength at the same time. It is an object of the present invention to provided a process for preparing a polyimide film characterized by extruding, casting and forming into a film a composition of a resin solution obtained by adding, to low viscosity varnish obtained by polymerizing a tetracarboxylic dianhydride component with a diamine component in a molar ratio of 1:1.01 to 1:1.05, or 1:0.95 to 1:0.99, a dehydrating agent in a molar ratio of at least one time and a chemically-imidizing catalyst in a molar ratio of at least half time based on 1 mole of the amic acid of the poly(amic acid) varnish.