Process for preparing high purity aluminum nitride
US4806330A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1987 |
| Grant date | Feb 21, 1989 |
| Priority date | — |
| Expiry date | Jun 2, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/80
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Process for producing high purity aluminum nitride powder by reacting aluminum sulfide with gaseous ammonia at an intermediate temperature (about 700.degree. C.) and holding at that temperature until an intermediate product (Al.sub.x N.sub.y S.sub.z) is formed where x, y, and z are integers; then further heating to a temperature above 1100.degree. C. and reacting with gaseous ammonia. A high purity, low oxygen containing, free flowing powder is produced. A posttreatment using a carbon source such as graphite further reduces the oxygen content. The oxygen content can be further reduced by reacting the aluminum nitride formed with carbon at about 1600.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.