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:
Feb. 06, 1990
Filed:
May. 05, 1988
Stephen Christensen, Woodinville, WA (US);
Jay O Rakel, Warrenville, IL (US);
The Boeing Company, Seattle, WA (US);
Abstract
A method is disclosed for forming poly(amide-imide) prepregs that permits forming void-free composites having residual solvent contents of less than 0.2% by weight. Such composite have improved glass transition temperatures near those of the pure polymer. In a preferred method, a poly(amide-imide) prepreg containing a residual N-methyl-2-pyrrolidone solvent is rapidly heated to about 650.degree. F. to evaporate residual solvent to less than 1.0% by weight. The prepreg is rapidly cooled before the thermoplastic poly(amide-imide) polymer begins to significantly advance in molecular weight. The prepreg may then be layed up to form composite articles that are consolidatable by application of further heat and pressure.