Production of polyurethane films or layered - products

摘要

Coating compositions of low viscosity, permitting better control of thickness and adherence, are prepared (without solvent) just before being used, by mixing, in presence of a polyurethane-resin crosslinking catalyst, approx. equivalent quantities of (1) liquid prepolymer with reactive isocyanate groups prepared by reaction of excess aromatic di-isocyanate with at least one glycol or glycol ether and (2) liquid polyol with reactive OH groups prepared by reaction of aromatic di-isocyanate with at least one diol and at least one triol. Unsupported films are useful for oil-resistant packaging, suitable substrates include leather and cloth.