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:
Sep. 17, 2002
Filed:
Nov. 13, 2001
Mitsuhiro Kanada, Osaka, JP;
Takayuki Yamamoto, Osaka, JP;
Amane Mochizuki, Osaka, JP;
Takahiro Fukuoka, Osaka, JP;
Nitto Denko Corporation, Osaka, JP;
Abstract
A method of efficiently removing a low molecular weight substance from a polyimide precursor or polyimide in which the low molecular weight substance is dispersed as micro-domains, without using a large amount of an organic solvent. The method of removing a low molecular weight substance comprises subjecting either a polymer composition having a micro-domain structure made up of a continuous phase comprising a polyimide precursor and, dispersed therein, a discontinuous phase comprising a low molecular weight substance or a polyimide composition obtained from the polymer composition by converting the polyimide precursor into a polyimide to extraction with a combination of supercritical carbon dioxide and a co-solvent to thereby remove the low molecular weight substance. The co-solvent is preferably an aprotic polar solvent, more preferably a nitrogen compound solvent or a sulfur compound solvent.