Infrared polarizing glasses
US4479819A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Oct 30, 1984 |
| Priority date | — |
| Expiry date | Sep 29, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/165
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The instant invention is directed to the preparation of glass articles exhibiting excellent polarization in the infrared portion of the spectrum from glasses characterized as containing silver halide particles therein selected from the group of AgCl, AgBr, AgI. The inventive method comprises four general steps: PA1 (a) a batch for a glass containing silver and at least one halide selected from the group of chloride, bromide, and iodide is melted and the melt shaped into a glass body of a desired geometry; PA1 (b) the glass body is subjected to a heat treatment at least above the strain point but not in excess of 50.degree. C. above the softening point of the glass for a period of time adequate to cause the generation of AgCl and/or AgBr and/or AgI particles therein, said particles ranging in size between 200-5000 .ANG.; PA1 (c) the glass body is elongated under stress at temperatures above the annealing point, but below that where said glass exhibits a viscosity of about 10.sup.8 poises, such that the particles are elongated to an aspect ratio of at least 5:1; and PA1 (d) the elongated glass body is exposed to a reducing environment at temperatures between 250.degree. C. and about …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.