Alumina isopipes for use with tin-containing glasses
US10421681B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 2011 |
| Grant date | Sep 24, 2019 |
| Priority date | — |
| Expiry date | Jun 29, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P40/57
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Isopipes (13) for making glass sheets using a fusion process are provided. The isopipes are made from alumina materials which have low levels of the elements of group IVB of the periodic chart, i.e., Ti, Zr, and Hf, as well as low levels of Sn. In this way, the alumina isopipes can be used with glasses that contain tin (e.g., as a fining agent or as the result of the use of tin electrodes for electrical heating of molten glass) without generating unacceptable levels of tin-containing defects in the glass sheets, specifically, at the sheets' fusion lines. The alumina isopipes disclosed herein are especially beneficial when used with tin-containing glasses that exhibit low tin solubility, e.g., glasses that have (RO+R2O)/Al2O3 ratios between 0.9 and 1.1, where, in mole percent on an oxide basis, (RO+R2O) is the sum of the concentrations of the glass' alkaline earth and alkali metal oxides and Al2O3 is the glass' alumina concentration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.