Optical glass and optical product
US6413894B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 27, 1999 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Apr 27, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S501/903
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
When a glass melt of an optical glass having a refractive index (nd) of at least 1.7 and an Abbe number (&ngr;d) of 28 to 41 is flowed down from a flow pipe made of Pt or a Pt alloy to form glass gobs continuously, there is caused a problem that the glass gobs have striae or that the weight variability among the glass gobs is large, and the problem can be overcome by the use of an optical glass comprising silicon oxide and boron oxide, the ratio of a content of the silicon oxide to a content of the boron oxide being greater than 0.78, the optical glass having a contact angle of at least 40° to Pt or a Pt alloy at a predetermined temperature equivalent to, or higher than, its liquidus temperature or in a predetermined temperature range whose lower limit is equivalent to, or higher than, the liquidus temperature and having a sag temperature Ts of 580° C. or lower.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.