FORMATION OF COLORING COMPLEXES IN GLASS COLORED WITH CERIUM AND TITANIUM OXIDES

摘要

The valence state of cerium and titanium ions in barium-strontium aluminosilicate glass with a different ratio of cerium and titanium oxides was investigated and the possible composition of the cerium-titanium complexes formed in silicate glass was analyzed. It was found that an active separate reaction between cerium and titanium oxides with the appearance of complex color centers takes place in synthesis of the glass. It is hypothesized that color centers primarily form between terravalent cerium and tetravalent titanium in glass-forming melts. A trend toward updating the product line on the automotive light market of items used in lighting and light-signaling equipment for motor vehicles. Incandescent lights with selectively yellow or auto yellow bulbs can be considered promising. According to the UN EEC rules (Unified Regulations Concerning Official Approval of Incandescent Lights for Use in the Officially Approved Headlights of Mechanical Vehicles), the colorimetric characteristics of such glass must satisfy the following requirements with respect to the chromaticity coordinates: for selectively yellow glass, the limit toward green (y < =x- 0.120), red (y >= 0.390), white (y <= 0.790 - 0.670X), and for auto yellow glass, the limits toward green, red, and white (y <= 1.29x- 0.1, y >=0.138 + 0.580x, y <= 0.966 - x, respectively). It is important to preserve the color in these articles both in direct production of the colored article and in it subsequent heat treatment and use.