Method of liquefying and condensing nitrogen trifluoride and a method of purifying nitrogen trifluoride
US4975259A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1989 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Jun 26, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/0837
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention has as its technical theme to provide a liquefactive and condensable method that enables the reaction step of forming NF.sub.3 to be operated safely and continuously and purifying method that eliminates O.sub.2, N.sub.2, etc. in NF.sub.3. The present invention is directed to a method wherein liquefaction and condensation of NF.sub.3 is carried out with an additive gas such as He, and Ne introduced in order to prevent H.sub.2 from mixing. The present invention is also directed to a purifying method wherein deeply cooled distillation of liquefied NF.sub.3 is carried out with one or more of He, He, and Ar introduced as a third component gas. According to the present invention, a safe long-term continuous operation has been made possible. Since O.sub.2, N.sub.2, etc. in NF.sub.3 can be eliminated efficiently, highly pure NF.sub.3 can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.