Method of producing 1,1,1,2,2-pentafluoroethane, a method of producing 2,2-dichloro-1,1,1-trifluoroethane, and a method of purifying 1,1,1,2,2-pentafluoroethane
US5847244A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1998 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Feb 13, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C17/395
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A production method in which reaction processes are divided into two regions comprising one reaction region where mainly perohloroethylene is made to react with HF in a vapor phase in the presence of a catalyst and the other reaction region where HCFC-123 (CF.sub.3 CHCl.sub.2) and/or HCFC-124 (CF.sub.3 CFHCl) is made to react with HF in a vapor phase in the presence of a catalyst, the former region being kept at a higher pressure and the latter region at a lower pressure during the reaction procedure. By this method it is possible to keep the conversion of perchloroethylene at a high level while securing the life of a catalyst, and it is also possible to raise the selectivity of HFC-125. This is a method of producing HFC-125 in which the content of CFC-115 is lowered to not more than 15 vol % of the total amount of HFC-125 and CFC-115, and then CFC-115 is made to react with hydrogen in the presence of a catalyst. By this method, reaction conditions can be lightened and the absolute amount of by-products also decreased, and the effective purification of HFC-125 can be realized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.