| 摘要 |
PURPOSE:To obtain the title high-purity compound at a low cost without complicated operations by reaction of a polyamine having plural amino groups with maleic anhydride in an organic solvent into polymaleamic acid followed by cyclodehydration in the presence of an acid catalyst and then distilling off the solvent. CONSTITUTION:A polyamine having in one molecule at least two amino groups {e.g. 2,2-bis[4-(4-aminophenoxy)phenyl]propane} is made to react with maleic anhydride under heating in an organic solvent like chlorobenzene or N-methyl-2- pyrrolidone to produce polymaleamic acid, which is, in turn, put to cyclodehydration under heating in the presence of an acid catalyst (e.g. p- toluenesulfonic acid) into polymaleimide. Thence, the reaction liquor is washed with water followed by distilling off 50-95wt.% of the organic solvent and then addition of an alcohol to deposit the polymaleimide, thus easily affording the objective high-purity polymaleimide at a low cost without the need for complicated operations. |
