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.
本发明提供了双组分聚
氨酯组合物,其中一个组分是由一种或多种双(
异氰酸酯甲基)
环己烷的异
氰尿酸酯或最好是两种或多种双(
异氰酸酯甲基)
环己烷的异
氰尿酸酯和六
亚甲基二异氰酸酯(
HDI 三聚体)的异
氰尿酸酯组成的多
异氰酸酯组合物,另一个组分是由羟基官能度为 2.5 至 5.0、分子量为 500 至 3 000 的软质多元醇和硬质多元醇组成的混合物。5 至 5.0,分子量为 500 至 3,000 的软质多元醇和硬质多元醇的混合物。这种组合物提供的涂料,尤其是透明面漆,除了硬度和柔韧性的良好平衡外,还具有优异的耐刮伤、耐磨损和耐溶剂性,而无需增加组合物的挥发性有机物含量(VOC)。此外,还提供了一种或多种双(
异氰酸酯甲基)
环己烷的异
氰脲酸酯与软质多元醇的多
异氰酸酯组合物,其挥发性有机化合物含量较低。