Method for the preparation of melamine
US6245909A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1998 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Dec 14, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D251/60
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a method for the preparation of melamine from urea via a high-pressure process in which solid melamine is obtained by transferring the melamine melt leaving the melamine reactor to a cooling vessel where the melamine melt is cooled by means of liquid ammonia. The melamine melt is cooled to a temperature of between about 50.degree. C. and about 350.degree. C. by means of liquid ammonia, a mixture comprising ammonia and melamine being formed, after which all or part of this mixture is transferred to an expansion vessel, the composition being contacted with ammonia for about one minute to about five hours, following which solid melamine is liberated from the composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.