| 摘要 |
<p>A transparent material in a monolithic or laminated sheet based on a methyl methacrylate homopolymer or a copolymer, the laminated material having at least one of its outer layers made of a methyl methacrylate homopolymer or copolymer, characterized in that the monolithic methyl methacrylate hompolymer or copolymer or the at least one outer methyl methacrylate homopolymer or copolymer layer of the laminated sheet exhibits an 0.1 to 1 g/cm3 increase in average density in the region of the surface for a depth of at least 50 nanometres from the surface, said average density being determined by X-ray reflectometry.</p> |
