Method for modifying coloration in tinted photochromic glasses
US4854957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1988 |
| Grant date | Aug 8, 1989 |
| Priority date | — |
| Expiry date | Apr 13, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C23/007
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A metod for making a photochromic glass article exhibiting a surface color pattern wherein a silver halide-containing photochromic glass article is treated by exposing at least a portion of the surface thereof to a patterned heat source for a time sufficient to raise the temperature of at least a part of the exposed portion above about 450.degree. C., is described. The glass may be exposed to the patterned heat source either before or after thermal reduction coloring. Patterned heating to a temperature in the transformation range of the glass is used where a post-patterning thermal reduction coloration step is to be used, in order to render the glass resistant to reduction coloration in the patterned area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.