| 摘要 |
PURPOSE:To obtain the titled compound in high yield, by reacting CH2Cl2 with HF under proper conditions in the presence of both a chromium fluoride and an aluminum fluoride or a catalyst obtained by supporting both the chromium fluoride and the aluminum fluoride on a carrier, or a catalyst prepared by blending them, followed by molding the blend. CONSTITUTION:In preparing difluoromethane by reacting dichloromethane with hydrogen fluoride, a chromium fluoride (e.g., CrF3, etc.) and an aluminum fluoride (e.g., AlF3, etc.), a catalyst obtained by blending the chromium fluoride and the aluminum fluoride with a carrier such as active carbon, molding the blend, or a catalyst prepared by supporting the chrominum fluoride and the aluminum fluoride on the carrier is used as the catalyst, and the gaseous-phase reaction is carried out at 200-500 deg.C, especially at 250-450 deg.C. A chromium compound and an aluminum compound treated with fluorine may be used as the chrominum fluoride and aluminum fluoride of the catalyst. EFFECT:Extremely advantageous economically. |
