Loading patent…
AssigneeMcDonnell Douglas Corporation
InventorsRobert W. Seibold, Haig S. Parechanian, William T. Weatherill, Robert E. Lowe
Estimating the term…
Production of composites having increased strength, particularly at elevated temperature, heat resistance and ablative properties, while maintaining low weight, by a process which comprises impregnating fibrous reinforcement, such as a woven fabric of graphite yarns, with a resin, e.g., a phenolic resin, curing the resin to yield a fiber-resin composite, pyrolyzing such composite to convert the resin to a porous carbonaceous matrix, reimpregnating the porous fiber-carbon composite with additional resin, such as a phenolic resin, to fill the pores of the matrix, and curing the reimpregnating resin. The resulting fiber reinforcement-resin matrix-carbon matrix (i.e., bimatrix) composites are particularly useful and valuable as reinforced plastic aerospace components requiring strength at high temperatures and having improved ablative properties.
The process for producing a plastic composite having improved elevated temperature strength and good heat resistance, which consists essentially of impregnating fibrous reinforcement material with a resin, curing said resin, pyrolyzing the resulting fiber-resin composite, reimpregnating the resulting pyrolyzed composite with additional resin and curing said additional resin, said resin reimpregnated composite forming a bimatrix fiber-resin-carbon composite composed of a mixture of pyrolyzed and non-pyrolyzed carbon and resin matrices reinforced with fibrous reinforcement material.
The process for producing a plastic composite having improved elevated temperature strength and good heat resistance, which consists essentially of impregnating fibrous reinforcement material comprised of fibers of graphite or carbon, with a concentrated solvent solution of a phenolic resin, at elevated temperature and under vacuum to boil away said solvent and then under pressure to ensure thorough penetration of said fibrous reinforcement material by said resin, to gelation of said resin, curing said resin at temperature ranging from about 275.degree. F. to about 450.degree. F., and forming an initial fiber-resin composite, pyrolyzing said fiber-resin composite at temperature ranging from about 1,300.degree. F. to about 1,900.degree. F. in an inert atmosphere, and substantially completely converting said resin of said fiber-resin composite to porous carbon, reimpregnating the resulting pyrolyzed porous fibrous reinforcement-carbon composite with additional liquid phenolic resin, at elevated temperature and under vacuum and then under pressure to ensure thorough penetration of said pyrolyzed porous completely by said additional resin, to gelation of said additional resin, and curing said additional resin at temperature ranging from about 275.degree. F. to about 450.degree. F., forming a bimatrix fibrous reinforcement-carbon-resin composite comprised of a mixture of carbon and resin matrices, and fibrous reinforcement, said carbon of said bimatrix fibrous reinforcement-carbon-resin composite being mechanically locked and adhered to said fibrous reinforcement.
Dependencies are inferred from the claim text.