| 摘要 |
<p>A coating composition particularly useful as a clear coating used over a pigmented base coat that has improved resistance to marring and to acid etching when exposed to natural weathering conditions containing 40-70 % by weight of film forming binder and 30-60 % by weight of a volatile liquid carrier for the binder; wherein the binder contains (a) 50-90 % by weight, based on the weight of the binder, of an acrylosilane polymer of polymerized monomers from the following group: an alkyl methacrylate, an alkyl acrylate, each having 1-12 carbon atoms in the alkyl group, cycloaliphatic alkyl methacrylate, cycloaliphatic alkyl acrylate, styrene or any mixture of these monomers; hydroxy containing monomers from the following group: hydroxy alkyl methacrylate, hydroxy alkyl acrylate each having 1-4 carbon atoms in the alkyl group, or any mixtures of these monomers; and a mono-ethylenically unsaturated silane monomer; and the polymer having a weight average molecular weight of 1,000-15,000 determined by gel permeation chromatography. (b) 10-50 % by weight, based on the weight of the binder of an organic polyisocyanate; and wherein the ratio of isocyanate groups of the organic polyisocyanate to hydroxy groups of the acrylosilane polymer is about 0.4:1 to 1.3:1.</p> |
