PROCESS FOR THE PREPARATION OF TETRAFLUOROETHYLENE BY DECHLORINATION AND DIMERIZATION OF DICHLORODIFLUOROMETHANE

摘要

1312348 Tetrafluoroethylene MONTECATINI EDISON SpA 4 June 1970 [4 June 1969] 27076/70 Heading C2C Tetrafluoroethylene is prepared by dechlorination and dimerization of dichlorodifluoromethane by treatment with an alkali metal or alkaline earth metal amalgam in a polar aprotic solvent. Solvents specified are hydrocarbons, carboxylic and phosphoric amides, nitriles, lactams, sulphones, sulphoxides, ethers, phosphates and carbonates. Reaction is preferably assisted by a promoter comprising a lithium salt or an oxonium, sulphonium, phosphonium or quaternary ammonium salt. The process may be batchwise or continuous. The amalgam may be obtained from an electrolytic cell, the exhausted amalgam being recycled to the cell. Reaction temperatures may be controlled thermostatically or by variation of the rate of feed of the amalgam. Polymerization inhibitors may be added, for example terpenes, e.g. limonene, phenol and quinones. The products may be separated by fractional distillation.