| 摘要 |
PURPOSE:To produce the objective compound in high yield over a long period, by carrying out dehydration reaction of dimethylphenyl carbinol in the presence of sulfuric acid catalyst while continuously distilling the reaction mixture keeping the alpha-methylstyrene concentration in the reaction liquid below a specific level. CONSTITUTION:alpha-Methylstyrene is produced by the continuous dehydrative reaction distillation of dimethylphenyl carbinol using 0.1-1wt.% of sulfuric acid as a catalyst while keeping the alpha-methylstyrene concentration in the reaction liquid at <=10%. The concentration of alpha-methylstyrene is maintained at <=10% preferably by controlling the reaction temperature, reaction pressure, feeding rate of raw material, etc., and the reaction temperature and pressure are preferably 80-150 deg.C and 20-300mmHg, respectively. it is not necessary to use a raw material having especially high purity and a material of 15-85% purity (by-product of the production process of phenol and acetone by the oxidation of cumene) can be used. The reaction solvent is preferably oligomer of alpha-methylstyrene. |
