Phase separated, non-crystalline opal glasses
AssigneeCorning Glass Works
InventorsJames E. Flannery, John L. Stempin, Dale R. Wexell
Life of this patent
Estimating the term…
Abstract
This invention is directed to the production of spontaneous essentially non-crystalline opal glasses exhibiting a very dense, milky-white appearance and excellent resistance to weathering and attack by alkaline detergents consisting essentially, expressed in weight percent on the oxide basis, of 2-5% K.sub.2 O, 4-10% Na.sub.2 O, 4.5-12% RO, wherein RO consists of 0-3% MgO, 0-6% CaO, 0-8% SrO, and 0-11% BaO, 4-9% B.sub.2 O.sub.3, 6-15% Al.sub.2 O.sub.3, 0-5% TiO.sub.2, 51-66% SiO.sub.2, 1-6% P.sub.2 O.sub.5, and 1-5% F.
Claims3
A spontaneous, essentially non-crystalline opal glass exhibiting a very dense, milky-white appearance, a softening point in excess of 700.degree. C., a coefficient of thermal expansion (25.degree.-300.degree. C.) between about 65-85.times.10.sup.-7 /.degree.C., an opal liquidus no higher than 1200.degree. C., and excellent resistance to weathering and attack by alkaline detergents consisting essentially, expressed in terms of weight percent on the oxide basis as calculated from the batch, of 2-5% K.sub.2 O, 4-10% Na.sub.2 O, 4.5-12% RO, wherein RO consists of 0-3% MgO, 0-6% CaO, 0-8% SrO, and 0-11% BaO, 4-9% B.sub.2 O.sub.3, 6-15% Al.sub.2 O.sub.3, 0-5% TiO.sub.2, 51-66% SiO.sub.2, 1-6% P.sub.2 O.sub.5, and 1-5% F.
Dependencies are inferred from the claim text.