Two component polyurethane coating compositions comprising isocyanurate compositions from bis (isocyanatomethyl) cyclohexane and from aliphatic diisocyanates

摘要

The present invention provides two-component polyurethane compositions comprising, as one component, polyisocyanate compositions of the isocyanurate of one or more bis(isocyanatomethyl)cyclohexane or, preferably, a mixture of two or more of these, and of the isocyanurate of hexamethylene diisocyanate (HDI trimer),and, as the other component, a mix of a soft polyol having a hydroxyl functionality of from 2.5 to 5.0 and a molecular weight of from 500 to 3,000, and a hard polyol. Such compositions provide coatings, especially clear topcoats, which exhibit excellent scratch and mar and solvent resistance in addition to a good balance of hardness and flexibility without the need for increasing the volatile organic content (VOC) of the compositions. Also provided are compositions of a polyisocyanate compositions of the isocyanurate of one or more bis(isocyanatomethyl)cyclohexane with soft polyol which have lower VOCs.