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:
Mar. 17, 1992
Filed:
Aug. 31, 1990
James R Barringer, Magnolia, AR (US);
H Eugene Broemmelsiek, Baton Rouge, LA (US);
Carroll W Lanier, Baker, LA (US);
Raymond Lee, Elk Grove Village, IL (US);
Ethyl Corporation, Richmond, VA (US);
Abstract
Polyimide foam of desired density is produced by adding to a polyimide precursor comprising carboxylic and diamine components at least one foam-enhancing polar, protic additive of the formula ROH, where R is hydrogen, or C.sub.1 to C.sub.12 linear or branched alkyl or cycloalkyl, unsubstituted or substituted with halo, aryl, alkoxy or hydroxy, and heating the resultant slurry to a temperature that does not exceed about 105.degree. C. to form a homogeneous melt. When heated to a higher temperature the melt foams and cures. The density of the foam is affected by the amount of foam-enhancing additive which is utilized.