Abstract: Described are photochromic organic resin compositions and the impact resistant polymerizates and coating compositions made therefrom. The organic resin composition comprises the reaction product of at least one polyol having greater than 1.0 hydroxyl groups; at least one polyisocyanate having greater than 1.0 isocyanato groups; and at least one polyamine curing agent having greater than 1.0 amino groups. The polymerizates are made photochromic either by the addition of organic photochromic compounds to the reactants used to form the polymerizate or by methods that imbibe or transfer the photochromic compounds into the polymerizate. Optically clear photochromic and impact resistant articles such as ophthalmic lenses and articles having photochromic coatings prepared from the photochromic organic resin compositions are also described.

Abstract: An intumescent nonhalogenated flame retardant polystyrene composition having high impact strength comprises polystyrene, ammonium polyphosphate, tris(2-hydroxyethyl) isocyanurate, hydrated zinc borate, and substantially amorphous elastomeric polymer.

Abstract: Small particles of ammonium dihydrogen phosphate, diammonium hydrogen phosphate, or a mixture thereof provide a higher Limiting Oxygen Index ("LOI") to polyolefin compositions containing the small particles than do larger particles of the same substance. In many instances, improvement in one or more other properties, such as for example, processability, appearance, UL-94 rating, tensile strength, tensile modulus, and/or elongation at break is also obtained.

Abstract: When tris(2-hydroxyethyl) isocyanurate and a long chain amine are employed together in intumescent flame retardant compositions, tris(2-hydroxyethyl) isocyanurate bloom is substantially reduced or even eliminated, and yet the flame retardant effectiveness of the tris(2-hydroxyethyl) isocyanurate is substantially retained.

Abstract: The water resistance of intumescent compositions is improved if the composition comprises polyol (alkyl carbonate).

Abstract: The water resistance of intumescent compositions is improved if the composition comprises at least one organotin derivative of a polyol. Organotin derivatives of polyols can be produced by reacting polyol with dialkyltin oxide or with dialkyltin dialkoxide.