Opal glasses having an apatite opacifying phase
US4536481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1984 |
| Grant date | Aug 20, 1985 |
| Priority date | — |
| Expiry date | Mar 23, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C3/118
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention is directed to spontaneous opal glasses containing an apatite opacifying phase and exhibiting a softening point of at least 740.degree. C., excellent chemical durability, and a temperature interval between the high temperature crystallization liquidus and the emulsion liquidus greater than 50.degree. C. The glasses consist essentially, in weight percent on the oxide basis, of ______________________________________ SiO.sub.2 50-63 Na.sub.2 O 5.5-10 Al.sub.2 O.sub.3 10-14 K.sub.2 O 0-10 P.sub.2 O.sub.5 3.5-7 BaO 0-10 PbO 2-12 CaO 0-2.5 B.sub.2 O.sub.3 1-4 SrO 0-8 F 1.5-4 BaO + CaO + SrO At Least 3 mole % ______________________________________
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.