Abstract: A process of manufacturing an aldimine preparation, characterized in that at least one aldimine of the formula (I), at least one isocyanate of the formula (II), optionally at least one alcohol of the formula (III) and water are reacted until at least 95% of all the initially present isocyanate groups are converted, whereby the initial molar ratio of aldimine groups to [isocyanate groups minus hydroxyl groups of the alcohol of formula (III)] in the reaction mixture is in the range of 2/1 to 10/1. The obtained aldimine preparation is particularly suitable for the use as latent hardener for moisture-curing polyurethane compositions. It enables moisture-curing polyurethane compositions with a very low content of diisocyanate monomers, which cure to an elastic material of surprisingly high strength, e-modulus and low surface tack.

Abstract: A moisture-curing polyurethane composition including: at least one isocyanate-functional polymer with a content of monomeric isophorone diisocyanate of below 0.5 weight-%, obtained from the reaction of isophorone diisocyanate and at least one polyol, and at least one aldimine of formula (I). The composition has a low toxicity, good shelf life stability and cures quickly to an elastic material of low surface tack and good mechanical properties, particularly in terms of high tensile strength and modulus of elasticity at high elongation. It enables coatings, sealants and adhesives with excellent stability under outdoor weathering conditions and high UV load. The aldimine of formula (I) allows to overcome the drawbacks caused by the removal of most of the monomeric isophorone diisocyanate in terms of cure speed, surface tackiness and final strength of such compositions.