Although it transforms in production manner and pentafluoro ethane of pentafluoro ethane, under existing

摘要

PURPOSE: To prepare pentafluoroethane in high purity with good productivity without causing problems when separating a by-product because the formation of chloropentafluoroethane as the by-product can be reduced or eliminated according to a specific method comprising a process of three stages. ;CONSTITUTION: This method comprises performing a step for producing a composition containing a compound of the formula: C₂HCl_xF_y [(x) is 1-3; (y) is 2-4] containing a compound of the formula: C₂Cl_x+1F_y mixed therein, a step for separating the compound of the formula: C₂HCl_xF_y from the compound of the formula: C₂Cl_x+1F_y and a step for bringing the compound of the formula: C₂ HCl_xF_y into contact with hydrogen fluoride in the presence of a fluorinating catalyst (preferably chromia or the chromia supporting zinc) preferably in the order. The method is preferably the one, etc., for chlorinating trichloroethylene or a compound of the formula: C₂H₂X₄ (X is F or Cl) and a composition in which the mixed compound of the formula: C₂Cl_x+1F_y is dichlorotetrafluoroethane and the compound of the formula C₂HCl_xF_y is chlorotetrafluoroethane is obtained.;COPYRIGHT: (C)1996,JPO