Binder system for ceramic arc discharge lamp
US6592695B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2000 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Nov 30, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2998/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A binder system for forming a ceramic body, such as a translucent arc tube for a metal halide lamp, comprises a hydrocarbon, such as a paraffin wax, a copolymer, such as poly (ethylene-co-vinyl acetate), and optionally a surfactant. The binder system is mixed with a ceramic powder and heated to above the melting point of the binder. The heated mixture is formed into a compact having the general shape of the finished ceramic body and then cooled or allowed to cool. The hydrocarbon and copolymer have overlapping freezing points so that when the shaped compact cools, crystalline segments of the copolymer (such as ethylene segments) co-crystallize with the hydrocarbon, while amorphous segments (such as vinyl acetate) form bridges between the crystalline regions. As a result, the cooled compact has improved green strength over conventional binder systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.