Lamp reflector substrate, glass, glass-ceramic materials and process for making the same
US7091141B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2004 |
| Grant date | Aug 15, 2006 |
| Priority date | — |
| Expiry date | May 31, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C10/0054
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention relates to glass, glass-ceramic materials, lamp reflectors and processes for making them. The glass material has a composition, by weight of the total composition, comprising 56–67% SiO2; 9–22% Al2O3; 3.4–3.8% Li2O; 1.8–2.6% ZnO; 1.5–2.5% MgO; 3.3–5% TiO2; 0–2.5% ZrO2; 1.5–3% B2O3; 0–6% P2O5; 0–0.6% F; less than 500 ppm Fe; and components resulting from effective amount of at least one refining agent. The glass-ceramic material of the present invention contains β-quartz solid solution as the predominant crystalline phase, and can be obtained by proper thermal treatment of the glass-ceramic material. The glass-ceramic material is particularly suitable for heat-resistant lamp reflectors which require a high surface smoothness Ra of lower than 75 nm, a low CTE between 25 and 300° C. of less than 10×10−7 K−1, and IR transmission at about 1050 nm of over 80% at a thickness of 3 mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.