| 摘要 |
<p>The present invention relates to moisture-hardening one-component lacquers having improved shelf life and thermal stability. These lacquers are characterized by high gloss and high flexural strength and are based on reaction products containing free isocyanate groups of relatively high molecular weight polyols having an average functionality of from 2 to 3, polyisocyanates and, optionally, low molecular weight polyhydroxyl compounds which are characterized in that the relatively high molecular weight polyol is a mixture of: (a) a hydroxyl polyester having an average molecular weight of from about 500 to 6000, (b) a hydroxyl polyether corresponding to the following general formula: <IMAGE> wherein R1 represents hydrogen, a C1-C4 alkyl radical or a phenyl radical, X represents one of the difunctional radicals -S-, -O-, -SO2-, -CO- or -C(R2R3)- where R2 and R3, which may be the same or different, represent hydrogen or a C1-C4 alkyl radical, and n and m each represent an integer of 22 0, the value of (n+m) being selected in such a way that the hydroxyl polyether has an average molecular weight of from about 300 to 1200. The present invention also relates to processes for the coating of substrates, particularly leather, and the coated substrates produced therefrom.</p> |
