Abstract: An improved curable epoxy resin composition of a vicinalpolyepoxide and an effective amount of a novel polyether thiourea curing agent is disclosed. The improved curable epoxy resins which are useful as coatings, castings, sealants, and adhesives show improved tensile shear strength, flexural strength, and ultimate elongation. The novel polyether thiourea curing agents of the instant invention are characterized by terminal primary amino groups and are formed by reaction of polyoxyalkylenepolyamines with thiourea, thiourea forming compounds or carbon disulfide.A preferred curing agent includes a mixture of a novel polyether thiourea formed by reaction of a polyoxypropylenepolyamine having a molecular weight of from about 200-2000 and an effective amount of carbon disulfide; and another known epoxy resin curing agent such as a polyoxyalkylenepolyamine in ratios of from about 5:1 to 1:5 by weight.

Abstract: An improved curable epoxy resin composition of a vicinalpolyepoxide and an effective amount of a novel polyether urea curing agent is disclosed. The improved curable epoxy resins which are useful as coatings, castings, sealants, and adhesives show improved tensile shear strength, flexural strength, and ultimate elongation. The novel polyether urea curing agents of the instant invention are characterized by terminal primary amino groups and are formed by reaction of polyoxyalkylenepolyamines with urea, urea forming compounds, or bifunctional isocyanates.A preferred curing agent includes a mixture of a novel polyether urea formed by reaction of a polyoxypropylenepolyamine having a molecular weight of from about 200-2000 and an effective amount of urea; and another known epoxy resin curing agent such as a polyoxyalkylenepolyamine in ratios of from about 5:1 to 1:5 by weight.

Abstract: Epoxy resins, of the polyglycidyl ether of a polyhydric phenol type, are cured by incorporating therein a polyoxyalkylenepolyamine and an accelerator combination of piperazine and an alkanolamine, the combination having a combined weight ratio of between about 1:8 to 1:1. The accelerator combination is synergistic for accelerating the curing of a polyglycidyl ether of a polyhydric phenol cured with a polyoxyalkylenepolyamine at ambient or elevated temperatures. The epoxy resin products are useful in protective coatings, adhesives, seamless and terrazzo flooring, castings, laminates, and in grouting, potting, encapsulating, caulking and sealing compositions.

Abstract: A polymerizable fire retardant unsaturated polyester resin composition is prepared by reacting a dicarboxylic acid with a polyhydric compound and an effective amount of 4,5-dibromohexahydrophthalic anhydride or its corresponding acid. The resulting unsaturated polyester resin composition when mixed with a polymerizable monomer containing terminal unsaturation and cured exhibits improved flame resistance at low bromine concentrations.