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:
Nov. 09, 2004
Filed:
Sep. 16, 2002
Hideki Ozawa, Chiba, JP;
Shigeru Yamamoto, Chiba, JP;
Ube Industries, Ltd., Yamaguchi, JP;
Abstract
A flexible polyimide foam having an apparent density of 13.5 to 900 kg/m and a glass transition temperature of 300° C. or higher can be prepared by mixing an aromatic tetracarboxylic acid comprising 2,3,3′,4′-biphenyltetracarboxylic dianhydride a portion of which is converted into its mono- or di-lower primary alcohol ester with an aromatic polyamine containing diaminodisiloxane in an amount of 0.1 to 10 mol. %, based on the amount of total amine compounds, to give a solid of polyimide precursor; heating the solid of polyimide precursor to a temperature of 300° C. to 500° C. to produce a polyimide foam; and compressing the polyimide foam.