Shrink-free ceramic and method and raw batch for the manufacture thereof
US4265669A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 14, 1979 |
| Grant date | May 5, 1981 |
| Priority date | — |
| Expiry date | Dec 14, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/6316
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention provides a hard, strong ceramic body and a ceramic raw batch and method for manufacture whereby the body, after being formed of the raw batch in the shape and size desired, can then be fired to monolithic structure without any shrinkage or distortion during the firing operation. The raw batch contains aluminum oxide, magnesium oxide, glass frit and a silicone resin, these constituents being present in a ratio such that after the firing operation the resulting monolithic body contains from about 70% to 95% by weight crystalline material and the remainder interstitial glass, the crystalline material consisting predominantly of magnesium aluminate spinel and alumina. The ceramic and method have particular utility for making dental crowns and other dental appliances where a precise fit along with high strength and wear resistance are desirable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.