Abstract: An improvement in the epoxy plastic element of a laminated, glass-plastic, ophthalmic lens structure, and a method of effecting the improvement, are disclosed. The improved element is cast from a casting mix in which the ingredients are maintained in certain relationships to each other to provide an optically clear casting essentially free of striations. The cast material is gelled at a low temperature not over about 100.degree. C., and may then be cured at a temperature up to 200.degree. for a period of at least two hours.

Abstract: This invention relates to the fabrication of three-layer composite lenses especially suited for ophthalmic applications. The lenses comprise a thin layer of an inorganic glass, desirably photochromic glass, an organic plastic, and an organic adhesive exhibiting flexibility and can be cured at temperatures in the vicinity of room temperature. In general, the linear coefficient of expansion of the glass ranges between about 60-120.times.10.sup.-7 /.degree.C. and that of the plastic between about 200-700.times.10.sup.-7 /.degree.C.

Abstract: Epoxy resins are rendered fire retardant by the addition thereto of a 3-hydroxyalkylphosphine oxide. Other halogen containing flame retardants may or may not be present in the composition. Mixtures containing a brominated epoxide and/or a halogenated phosphine oxide provide a high level of flame retardance at low levels of the additive. The epoxy resins may be heat cured in the presence of an acid anhydride or amine to form a polymer having the phosphine oxide incorporated in the polymer molecule.

Abstract: Epoxy resins are rendered fire retardant by the addition thereto of a 3-hydroxyalkylphosphine oxide. Other halogen containing flame retardants may or may not be present in the composition. Mixtures containing a brominated epoxide and/or a halogenated phosphine oxide provide a high level of flame retardance at low levels of the additive. The epoxy resins may be heat cured in the presence of an acid anhydride or amine to form a polymer having the phosphine oxide incorporated in the polymer molecule.

Abstract: Mixed ether compositions containing oligomers of polyhydroxyalkyl phosphine oxide are prepared by heating a polyhydroxyalkyl phosphine oxide in the presence of an acid catalyst at temperatures within the range of from about 139.degree. C. to about 200.degree. C. and removing water from the reaction mixture. When the reaction is conducted in the presence of an aliphatic, cycloaliphatic or aromatic alcohol having one or more hydroxyl groups mixed phosphine oxide ethers of the added alcohol are formed. The mixed ether compositions of the present invention are useful fire retardant additives.

Abstract: Epoxy resins are rendered fire retardant by the addition thereto of a 3-hydroxyalkylphosphine oxide. Other halogen containing flame retardants may or may not be present in the composition. Mixtures containing a brominated epoxide and/or a halogenated phosphine oxide provide a high level of flame retardance at low levels of the additive. The epoxy resins may be heat cured in the presence of an acid anhydride or amine to form a polymer having the phosphine oxide incorporated in the polymer molecule.