| 摘要 |
<p>A thin, abrasion resistant polyurethane coating which is hydrolytically and oxidatively stable is prepared by reacting a polycarbonate diol having a molecular weight less than 500 with an aliphatic, preferably cycloaliphatic, diisocyanate, and curing with a trifunctional cross linking agent. A method for applying a thin abrasion resistant polyurethane coating while minimizing exposure to volatile free isocyanate is also disclosed. The method involves forming a hydroxy-terminated prepolymer which is subsequently crosslinked using a relatively non- volatile triisocyanate having a molecular weight greater than 500, and applying the material by flow coating or dip coating techniques, rather than spraying, in order to minimize volatilization. An abrasion resistant coated article comprising a rigid transparent substrate and a crosslinked polycarbonate urethane coating is also disclosed. The substrate may be selected from acrylic, polycarbonate and polyurethane sheets, or may be a laminate comprising a glass sheet and a layer of thermoplastic polymer, e.g. a polyurethane.</p> |
