Dispersion of Bicomponent Polyurethane Coatings of Aqueous, Solvent-Free or Low-Volatile Organic Compounds

摘要

The present invention has an adhesive force when a dispersion of an aqueous solvent-based two-component coating composition which is almost solvent-free is applied to a support, and is bonded with the same or better adhesion properties as a film obtained with a conventional solvent-based two-component polyurethane or epoxy system. A dispersion of a two-component coating composition that is cured into a film having properties. The first component is a mixed component of the aqueous polyol phase and the amine phase. The polyol phase consists of an acid containing polyol or a polyol mixture comprising an acid containing polyol and is a component having an average hydroxyl functionality of at least 1.5 and an acid value of about 15 to 200. The amine phase is an amine or amine mixture comprising active hydrogens having an average active hydrogen functionality of at least 1.5 and having reactivity with NCO groups. The amine phase is present in an amount sufficient to nearly neutralize the acid containing polyols. The second component is a component selected from the group consisting of aliphatic polyisocyanates, cycloaliphatic polyisocyanates, aromatic polyisocyanates, adducts thereof and mixtures thereof. The ratio of the sum of the isocyanate equivalents to the active hydrogen equivalents of the polyols and fishermen is at least 0.5: 1, preferably at least 1.1: 1. The selective reaction of isocyanate groups and active hydrogen moieties from polyols with amines results in linear and crosslinking polymerization reactions.