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. 15, 2000
Filed:
Nov. 04, 1997
Anthony M Mazany, Akron, OH (US);
Stanley G Prybyla, Brecksville, OH (US);
Ohio Aerospace Institute, Brook Park, OH (US);
Abstract
The service life of fiber-reinforced polyimide composites in a high temperature oxidative environment is extended by coating with a polyimide coating precursor solution that is synthesized by reacting an aromatic dianhydride with an aromatic diamine in a non-reactive solvent. The reactive solution is heated to a temperature sufficent to reduce its viscosity prior to its use as a coating. Preferably, a mixture of meta-phenylenediamine and para-phenylenediamine is reacted with biphenyldianhydride in n-methyl pyrrolidinone solvent and thereafter heated to between about 50.degree. C. (122.degree. F.) and 150.degree. C. (302.degree. F.) under nitrogen while stirring for a time sufficient to obtain a polyamic acid polyimide precursor coating solution having a Brookfield viscosity of from about 500 to about 5000 cP and a solids content of from about 5 to about 35 weight percent.