PURIFICATION OF 1,1-DICHLORO-1-FLUOROETHANE

PURPOSE:To selectively and readily remove 1,1-dichloroethylene which can not be distilled off by bringing crude 1,1-dichloro-1-fluoroethane into contact with concentrated sulfuric acid. CONSTITUTION:1,1-Dichloro-1-fluoroethane containing 1,1-dichloroethylene is brought into contact with concentrated sulfuric acid preferably having a concentration of >=95% at 25-100 deg.C for the purification. Being the primary cause for decreasing the concentration of sulfuric acid, water contained in the compound to be treated is desirably preliminarily dehydrated with a drying agent such as sulfuric acid, silica gel or molecular sieve. The weight ratio of the sulfuric acid to the compound to be treated is preferably 1:10 to 1:0.01 and the method for bringing the sulfuric acid into contact with the compound to be treated includes the mixing thereof in a reactor equipped with a stirrer, the mixing thereof by the use of a line stirrer, etc., and is not specifically limited. The title substance is useful as a foaming agent for urethane foams, a cleansing agent for removing fats, oils or flux, a solvent for dry cleansers, etc.