초록 ▼

Polyurethane resins are described having high impact strength and other structural strength properties, and significantly improved resistance to deformation by heat. The properties of these materials are such as to make them comparable to engineering thermoplastics such as nylon and like materials c

Polyurethane resins are described having high impact strength and other structural strength properties, and significantly improved resistance to deformation by heat. The properties of these materials are such as to make them comparable to engineering thermoplastics such as nylon and like materials commonly used to fabricate structural components such as automotive parts, equipment housing, sporting goods, furniture, toys, household and like consumer goods. The resins are prepared from organic polyisocyanates, an isocyanate-reactive material (polyol, polyamine, etc.) having an average functionality of at least 1.9, a Tg less than 20°C. and molecular weight of 500-20,000, and one or more low molecular weight extenders the major distinguishing feature being the markedly lower proportion by weight (2 to 25 percent) in which the isocyanate-reactive material is employed as compared with polyurethane resins conventionally prepared in the art. Depending upon the particular combination of reactants employed the polyurethanes of the invention can be thermoplastic or thermoset and can be prepared in both cellular and non-cellular form.

대표청구항 ▼

A polyurethane characterized by high impact resistance, high flexural modulus, and a heat deflection temperature of at least 50°C. at 264 psi which comprises the product of reaction of (a) an organic polyisocyanate; (b) an isocyanate-reactive material having an average functionality of at least 1.9,

A polyurethane characterized by high impact resistance, high flexural modulus, and a heat deflection temperature of at least 50°C. at 264 psi which comprises the product of reaction of (a) an organic polyisocyanate; (b) an isocyanate-reactive material having an average functionality of at least 1.9, a glass transition temperature (Tg) of less than 20°C., and a molecular weight in the range of about 500 to about 20,000; and (c) at least one chain extender having a functionality from 2 to 3 and a molecular weight from about 50 to about 400; said polyurethane being further characterized in that the proportion by weight of said isocyanate-reactive material (b) in said polyurethane is from about 2 to about 25 percent and the overall ratio of isocyanate groups to active hydrogen groups in said reactants employed to prepare said polyurethane is in the range of 0.95:1 to about 1.05:1.