Patent ID: 6887950

Claim:
A flame-retardant curable epoxy composition comprising: (a) an epoxy resin; (b) a co-crosslinking polyhydroxy mixture including: (i) a mixture of phosphine oxides including hydroxyaryl phosphine oxides of the formulae: (A) a mono(hydroxyaryl)phosphine oxide of the formula: wherein R 1 is a divalent, substituted or unsubstituted arylene moiety and R 2 is a monovalent, substituted or unsubstituted aryl moiety or is an alkyl moiety or is an aralkyl moiety; and (B) a bis(hydroxyaryl)phosphine oxide of the formula: wherein R 1 and R 2 are defined as above; and (C) a tris(hydroxyaryl)phosphine oxide of the formula: wherein R 1 is defined as above; and (D) optionally containing minor amounts of a pentavalent phosphine oxide of the formula: wherein R 2 is defined as above; and (ii) a phenolic co-crosslinking composition comprising a phenolic component having a hydroxyfunctionality of two or more.