| 摘要 |
1487529 Coated organic glass SAINTGOBAIN INDUSTRIES 6 Aug 1976 [7 Aug 1975] 32862/76 Heading B2E [Also in Division G2] A body of transparent organic glass has on at least one surface a coating of soft plastics material able to self-heal after scratching less than 60 seconds at 25‹C and ambient relative humidity of 80%. The organic glass may be a copolymer comprising 60-98% methyl methacrylate, 1-30% diethyleneglycolbis (allylcarbonate) and 1-10% of trimethylolpropanetrimethacrylate. The coating may be of a polyurethane comprising as components a polyglycolether resulting from condensation of propylene oxide and trimethylolpropane containing 10.5-12% of OH groups (component I) and a biuret of 1-6 hexamethylene-diisocyanate containing 21-22% of isocyanate groups (component II), the weight ratio of II to I being from 0.9 to 1.1. The organic glass may be tinted in the mass or may be soaked in a colouring bath before or after coating. A semi-reflecting layer may be on at least one surface. The body may be in the form of a lens, mask, screen or visor. |
