摘要 |
<p>{PG,1 An article coated with an abrasion resistant coating is disclosed in which the coating comprises a polyvinyl acetal having an hydroxyl group content, calculated as polyvinyl alcohol, of from 35 to 50 percent by weight and silicic acid, the weight ratio of silicic acid to polyvinyl acetal being from 2:1 to 4:1.</p> |