| 摘要 |
1413544 Photochromic polymer compositions AMERICAN OPTICAL CORP 3 July 1973 [3 July 1972 15 June 1973] 31634/73 Heading C3P [Also in Divisions G2 and C4] A photochromic light filter, e.g. in ski goggles or sun-glasses comprises a transparent plastics substrate containing a metal dithizonate, the filter being formed by immersion in a saturated metal dithizonate solution at an elevated temperature so as to imbibe the dithizonate into the substrate, the solution solvent being a non- solvent for the substrate. Detailed metal dithizonates are exemplified, and also substrates such as polyallyl diglycol carbonate, polycarbonate and poly-lower aliphatic methacrylates. |
