Phosphor-coating composition and method for electric discharge lamp
US4265950A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1979 |
| Grant date | May 5, 1981 |
| Priority date | — |
| Expiry date | Nov 27, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/25
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Improved adhesion of the phosphor coating in a fluorescent lamp having a transparent film of conductive material (such as tin oxide) on the inner surface of the bulb is obtained by adding small but correlated amounts of finely-divided aluminum oxide, calcium nitrate, and ammonium nitrate to the water-base phosphor-coating composition. The combination of additives bonds the phosphor particles to the bulb despite the intervening layer of tin oxide and the lower lehring temperature required to preserve its conductivity. When the conductive film is composed of a material which can tolerate higher lehring temperatures, other additives such as barium nitrate, cadmium nitrate and strontium nitrate can be substituted for or admixed with the calcium nitrate. Alternatively, the ammonium nitrate additive can be eliminated by admixing selected quantities of calcium nitrate and barium nitrate (for example, a blend of 65 mole % calcium nitrate and 35 mole % barium nitrate) to form a "two-component" additive which melts at a lower temperature than either of the constituents in the blend. Two-component additives containing blends of properly correlated amounts of barium nitrate-strontium nitrate a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.