John P Donahoe

US Patent:

42554837, Mar 10, 1981

Filed:

Jun 14, 1977

Appl. No.:

5/806540

Inventors:

Norman R. Byrd - Villa Park CA
John K. Donahoe - Long Beach CA

Assignee:

McDonnell Douglas Corporation - Long Beach CA

International Classification:

B32B 700

US Classification:

428245

Abstract:

Fire barrier composition particularly applicable as an acoustic panel-fire wall structure in aircraft, capable of withstanding a 2,000. degree. F. flame temperature, comprising incorporating a silica-containing material such as silicic acid or the reaction product of silicic acid and maleic anhydride, into a resin, particularly a polyimide resin. The resulting silica-containing resin, e. g. silicic acid-filled polyimide, is then applied to a substrate such as graphite fiber or glass cloth, to form a composite structure, which is then cured. The resulting cured composite when subjected to high temperature, e. g. a 2,000. degree. F. flame temperature, forms silicon carbide and/or silicon nitride, in situ, which stabilizes any char that forms.