UV-absorbing, polarizing glass article
AssigneeCorning Incorporated
InventorsRoger J. Araujo, Nicholas F. Borrelli, Josef C. Lapp, David W. Morgan
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Abstract
A UV-absorbing, polarizing glass article and method of making, the glass having an R.sub.2 O-B.sub.2 O.sub.3 -SiO.sub.2 base glass composition, a sharp spectral cut-off at about 400 nm, a precipitated crystal phase consisting of a halide selected from the group composed of cuprous, cadmium and mixed cuprous-cadmium halides, the crystallites in the crystal phase being elongated, and a portion of the crystallites near the surface of the article being at least partially reduced to colloidal copper, whereby the article exhibits permanent dichroic behavior.
Claims12
A UV-absorbing, polarizing glass article, the glass having an R.sub.2 O-B.sub.2 O.sub.3 -SiO.sub.2 base glass composition, a sharp spectral cut-off at about 400 nm, a precipitated crystal phase consisting of halide crystallites selected from the group composed of cuprous, cadmium and mixed cuprous-cadmium halide crystallites, the crystallites in the crystal phase being elongated, and a portion of the crystallites near the surface of the article being at least partially reduced to colloidal copper, whereby the article exhibits permanent dichroic behavior.
A method of producing a UV-absorbing, polarizing glass article which comprises the steps of melting a batch for a R.sub.2 O-B.sub.2 O.sub.3 -SiO.sub.2 base glass containing at least 0.2% by weight Cu.sub.2 O together with a sufficient amount of at least one halogen selected from chlorine and bromine to react with at least 0.2% copper, precipitating cuprous halide crystallites in the glass, subjecting the glass to a stress in one direction to elongate the glass and the cuprous halide crystallites therein, and then exposing the glass to a reducing atmosphere to reduce at least a portion of the copper halide crystallites in a thin layer near the surface of the glass.
Dependencies are inferred from the claim text.