| 摘要 |
PURPOSE:To separate trioxane according to the pervaporation operation by heating an aqueous solution of formaldehyde in the presence of an acidic catalyst and then reacting the heated aqueous solution with the trioxane. CONSTITUTION:An aqueous solution of formaldehyde is heated at 70-110 deg.C in the presence of an acidic catalyst (e.g. an ion exchange resin) and reacted with trioxane. The trioxane produced during the reaction is separated while removing the trioxane from the aqueous solution containing the formaldehyde according to the pervaporation separating method to afford the trioxane. The trioxane formed by the reaction can be removed by the pervaporation separating method simultaneously or alternately with the reaction to provide the trioxane from the aqueous solution of the formaldehyde in high selectivity and yield at a low energy cost. The trioxane is useful as a monomer for polyacetal resins which are engineering plastics. |
