| 摘要 |
PROBLEM TO BE SOLVED: To prepare an aromatic polyamide film which contains basic structural units respectively shoen by the specific formuals, extremely small in the amount of an reduced extract with chloroform such as oligomers and is excellent in heat resistance and mechanical characteristics and useful as a magnetic recording medium due to its smooth surface. SOLUTION: This aromatic polyamide contains∞50 mole % of basic structural units of formula I (Ar1 and Ar2 are each formula II or like) and 3-30 mole % of basic structural units of formula III [Ar3 and Ar4 are each formula IV or the like (X and Y are O, CH2 , CO, etc.) and the others are formula II] and the extract with chloroform from the polymer is regulated to <=0.5wt.%. When the weight fraction of the aromatic polyamide is regarded as 100, the weight fraction of the substituents in the aromatic ring as S1 and the amide group constituting the main chain of the polyamide as S2, they preferably satisfy the formula: S2/(100-S1)<=0.33. |
