Copper aluminoborate glasses
Abstract
Abstract The instant invention is concerned with the production of glasses in the copper borate composition field wherein Al2O3, though not required, is a very desirable additive. Such glasses exhibit low softening points and coefficients of thermal expansion ranging between about 30-50 X 10 7/*C. Those properties impart the special utility of enabling sealing to commercial alkali borosilicate glasses (and glasses of that expansion range) without deformation of the alkali borosilicate. The electrical properties of both the bulk and the surface glass can be altered through variations in oxidizing and reducing conditions. The compositions of the glasses in weight percent on the oxide basis, wherein copper is deemed to be present as CuO, range between about 25-55% CuO, 0-25% Al2O3, and 25-70% B2O3.
Inventors
- 👤 Joseph W Malmendier
Bibliographic Details
Claims Analysis
Total Claims: 4References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |