EP0770588A1
Expired / Lapsed
EP
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Process for producing difluoromethane
Assignee: Daikin Industries Ltd
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Filing: 1995-07-03
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Granted: —
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Expires: 2015-07-03
Abstract
Abstract According to a process for producing difluoromethane by fluorinating dichloromethane with hydrogen fluoride in a liquid phase in the presence of a catalyst, wherein the reaction is conducted at a temperature within the range from 80 to 150°C under a pressure within the range from 8 to 80 kg/cm 2 using a mixture of antimony pentafluoride and antimony trifluoride, or antimony pentafluoride as the fluorinating catalyst, difluoromethane can be economically and safely produced from dichloromethane and hydrogen fluoride.
Inventors
- 👤 Yasufu Yamada
- 👤 Takashi Shibanuma
- 👤 Takehide Tsuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 16:44
CPC Classifications
B; B01; B01J; B01J27/00; B01J27/06; B01J27/08; B01J27/12; C; C07; C07C; C07C17/00; C07C17/093; C07C17/20; C07C17/202; C07C17/206
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
85 words
A process for producing difluoromethane comprising reacting dichloromethane with hydrogen fluoride in a liquid phase in the presence of a fluorinating catalyst, wherein the reaction is conducted at a temperature within the range from 80 to 150°C under an absolute pressure within the range from 8 to 80 kg/cm 2 using a mixture of antimony pentafluoride and antimony trifluoride, or antimony pentafluoride having a concentration of not more than 2% by mol based on hydrogen fluoride in a liquid phase mixture, as the fluorinating catalyst.
Claim 2
Dependent Claim
43 words
The process according to claim 1, wherein the mixture of antimony pentafluoride and antimony trifluoride is used as the fluorinating catalyst in an amount within the range from 0.2 to 10 % by mol based on hydrogen fluoride in the liquid phase mixture.
Claim 3
Dependent Claim
31 words
The process according to claim 1 or 2, wherein hydrogen fluoride is present in the liquid phase mixture in an amount of at least 5 mol per one mol of dichloromethane.
Claim 4
Dependent Claim
39 words
The process according to any one of claims 1 to 3, wherein the reaction is conducted at the temperature and pressure at which hydrogen fluoride and dichloromethane remain but hydrogen chloride and difluoromethane to be formed are distilled off.
Claim 5
Dependent Claim
26 words
The process according to any one of claims 1 to 4, wherein a reactor for conducting the reaction has a reflux column and a reflux condenser.
Claim 6
Dependent Claim
38 words
The process according to any one of claims 1 to 5, wherein the reaction is conducted in the reactor of a material selected from the group consisting of Hastelloy C, Hastelloy G, double-phase stainless steel (DP-3) and NAR25-50MTl.
Claim 7
Dependent Claim
79 words
The process according to any one of claims 1 to 6, which comprises the steps of: (1) charging the fluorinating catalyst and hydrogen fluoride into a reactor; (2) adding dichloromethane, or dichloromethane and hydrogen fluoride to the reactor to react them; (3) removing a part or all of the reaction mixture; (4) separating the removed reaction mixture by a distillation to give difluoromethane; and (5) optionally returning hydrogen fluoride, dichloromethane and chlorofluoromethane in the reaction mixture to the reactor.
Claim 8
Dependent Claim
13 words
The process according to claim 7, which is conducted by a continuous process.
Claim 9
Dependent Claim
27 words
The process according to claim 7 or 8, wherein difluoromethane and hydrogen chloride are removed from the reactor and hydrogen fluoride, dichloromethane and chlorofluoromethane are not removed.
References Cited (Backward Citations)
No citation records indexed.
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