| 摘要 |
PURPOSE:Crude acetic anhydride containing diketene is treated with an ion- exchange resin, when needed, simultaneously or subsequently distilled to give acetic anhydride of high quality which is used as a starting material for acetylcellulose, medicines, agrochemicals or dyes. CONSTITUTION:Crude acetic anhydride containing diketene is treated with 0.1-1.0wt% of an ion-exchange resin at room temperature to 130 deg.C for 1-3hr under stirring or in addition, the treatment product is subjected to batchwise single distillation under reduced pressure of about 100Torr to effect purification. The ion-exchange resin is preferably an anion-exchange resin, e.g. Amberlite IRA-68, IRA-94, Amberlist A-21. EFFECT:Diketene is removed to a level of 5ppm (undetectable) economically through a simple process and the separation of the ion-exchange resin also is simple. The product is pure enough to be used without problem, as starting material in the field of fine chemistry.
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