Azeotropes of hydrogen fluoride with dichloromethane, difluoromethane and chlorofluoromethane
US5523015A · kind A · utility
13Cited by
9References
8Claims
0Family size
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Key dates
| Filing date | Dec 9, 1993 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | Dec 9, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B7/195
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.