Method for making infrared polarizing glasses
US4908054A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1989 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Feb 21, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C4/06
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention is directed to the preparation of glass articles exhibiting a relatively broad band of high contrast polarizing properties in the infrared region of the radiation spectrum from glasses containing silver halide particles selected from the group consisting of AgCl, AgBr, and AgI. The inventive method comprises the following five general steps: PA0 (a) melting a batch for a glass containing silver and at least one halide selected from the group consisting of chloride, bromide, and iodide; PA0 (b) cooling and shaping said melt into a glass article of a desired configuration; PA0 (c) subjecting said glass article to a temperature at least above the strain point, but not in excess of 75.degree. C. above the softening point of the glass, for a sufficient length of time to cause the generation of silver halide particles therein selected from the group consisting of AgCl, AgBr, and AgI, said particles ranging in size between about 200-5000 .ANG.; PA0 (d) elongating said glass article under stress at a temperature above the annealing point, but below that where said glass exhibits a viscosity of about 10.sup.8 poises, such that said silver halide particles are elongated to an …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.