Patent ID: 7592072

Claim:
A prepreg composite material comprising: 1) a fiber layer; and 2) a prepreg resin comprising: A) a eutectic bismaleimide resin component comprising: a) a first bismaleimide monomer selected from the group consisting of N,N′-4,4′-diphenylmethane-bis-maleimide and N,N′-4,4′-diphenyl-ether-bis-maleimide; b) a second bismaleimide monomer selected from the group consisting of N,N′-2,4-toluene-bis-maleimide, N,N′-2,6-toluene-bis-maleimide and N,N′-meta-phenylene-bis-maleimide; and c) a third bismaleimide monomer selected from the group consisting of N,N′-2,2,4-trimethylhexane-bis-maleimide and N,N′-4,4′-diphenyl-ether-bis-maleimide; and d) a comonomer selected from the group consisting of diamines, polyamines and alkenyl aromatic compounds; B) a thermoplastic toughening agent consisting essentially of polyimide; and C) a resin distribution stabilizer consisting essentially of polyethylene oxide having a molecular weight of between about 150,000 and about 5,000,000 Daltons, said resin distribution stabilizer being present in a sufficient amount to prevent said prepreg resin from flowing away from said fiber layer during storage of said prepreg composite material.