Method for the preparation of difluoromethane
US5495057A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1995 |
| Grant date | Feb 27, 1996 |
| Priority date | — |
| Expiry date | Mar 2, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C17/206
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
There is disclosed a method for the preparation of difluoromethane wherein methylene chloride is reacted with. hydrogen fluoride in liquid phase, at a temperature of about 70.degree. to 90.degree. C. under a pressure of about 11 to 12 kg/cm.sup.2.g in the presence of antimony pentachloride. It is important that the concentration of quinquevalent antimony is maintained at a level of 85% or more with the feed mole ratio of hydrogen fluoride to methylene chloride ranging from about 2.0 to 2.3. Applicable to industrial scale, the method is operated in a batch system or in a continuous system. In addition, it exhibits superior conversion rate of the materials and production yield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.