Heat-resistant sealing materials
US4330629A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1979 |
| Grant date | May 18, 1982 |
| Priority date | — |
| Expiry date | Jun 7, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C8/24
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Sealing materials for making heat-resistant seals in electrical discharge devices comprise a rare earth oxide, such as lanthanum oxide, and boric oxide, preferably together with minor amounts of phosphorus pentoxide, aluminium oxide and magnesium oxide. Preferred compositions comprise 55 to 95% lanthanum or other oxide, 5 to 45% boric oxide and 0 to 5% phosphorus pentoxide, 0 to 5% aluminium oxide and 0 to 5% magnesium oxide. The compositions can be made by mixing the oxides, or appropriate salts, calcining the mixture at up to 1200.degree. C. and crushing it to a powder. They may be used as frits in a slurry or formed into pressed elements such as discs or washers. Sealing can be accomplished by heating the surfaces to be joined, together with the interposed sealing composition, to a temperature between 1100.degree. and 1650.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.