| 摘要 |
PURPOSE:To obtain a high-purity dehydration condensate in high yields without purification, by reacting a methylol group-containing phenol with an excess of a phenol, distilling off a portion of unreacted reactants, adding a precipitant to the reaction mixture to precipitate the polymer. CONSTITUTION:1mol of a methylol group-containing phenol of formula I or II[wherein R<1> is CH3, C2H5, C3H7, or C4H9, R<2>, R<3>, and R<5> are each H, a 1- 30C alkyl, aralkyl, methoxy, hydroxyl group, Cl, Br, p-toluenesulfonato or a like group, and R<4> is methylene, ethylidene, or oxy(methylene)] is reacted with 1- 50mol of a phenol of formula III (wherehin R<6-7> are each H, a 1-30C alkyl or aralkyl) at 40-200 deg.C for 20min-50hr in the presence of a polyphosphoric acid catalyst. A portion of unreacted phenols in the reaction poduct is removed by vacuum distillation, and a precipitant (e.g., methanol) is added to the residual reaction solution to precipitate a dehydration condensate, which is then filtered, washed and dried. |
