High density cordierite ceramics from zeolite
US4980323A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Dec 19, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/195
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to processes for preparing ceramic articles which are especially suited for electronic applications. The process involves taking a shaped article which has been formed from a magnesium exchanged zeolite powder, the zeolite selected from the group consistig of phillipsite, harmotome, gismondine, zeolite B, zeolite ZK-19 and zeolite W, and sintering it at a temperature of about 1,000.degree. to 1,350.degree. C. for about 1 to about 6 hours. The magnesium exchanged zeolite has a SiO.sub.2 /Al.sub.2 O.sub.3 ratio of about 2.3 to about 2.8 and a sodium content less than 0.5 weight percent. The ceramic article that is formed has a substantially crystalline cordierite phase and has a density of at least 90% of its theoretical density. A preferred process involves calcining the magnesium exchanged zeolite powder at a temperature of about 600.degree.-800.degree. C. to collapse the zeolite framework and give upon sintering a cordierite ceramic article which is substantially crack free. A preferred magnesium exchanged zeolite is magnesium exchanged zeolite B.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.