Method of preparing 1,1,1,2-tetrafluoroethane from 1,1-dichloro-1,2,2,2-tetrafluoroethane
US4996379A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1989 |
| Grant date | Feb 26, 1991 |
| Priority date | — |
| Expiry date | May 26, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C17/23
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
1,1,1,2-Tetrafluoroethane, a refrigerant, is formed with little formation of isomers or chlorofluoroethanes having not very different boiling points by reacting 1,1-dichloro-1,2,2,2-tetrafluoroethane (R-114a), which may contain up to about 25 wt% of 1,2-dichloro-1,1,2,2-tetrafluoroethane (R-114), with hydrogen gas in the presence of a palladium-on-active alumina catalyst at a temperature lower than 200.degree. C. and not lower than 120.degree. C. R-114a almost free of R-114 is obtained by reacting 1,1,1-trichloro-2,2,2-trifluoroethane with hydrogen fluoride in vapor phase in the presence of a catalyst prepared by partially fluorinating .gamma.-alumina by treatment with hydrogen fluoride gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.