| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing a polyamic acid solution having low viscosity in spite of its high density, thus having a narrow molecular weight distribution, further excellent in stability over a long period, and suitably usable, e.g., as the one for a varnish and a film activating these characteristics.SOLUTION: Provided is a method for producing a polyamic acid where diamine is dissolved into an organic solvent under stirring, to the obtained solution, diamine and tetracarboxylic acid dianhydride by a substantially equimolar amount are dividedly added under stirring in such a manner that an insoluble matter is not left, dissolution is performed, further, stirring is continued, the diamine and the tetracarboxylic acid dianhydride are brought into polyaddition reaction to produce a polyamic acid oligomer, a reaction container stored with a uniform solution including the obtained polyamic acid oligomer is mounted on a revolution-rotation centrifugal type stirrer, the reaction container is rotated while being revolved, and the further production of the polyamic acid oligomer and polymerization by the polyaddition reaction of the polyamic acid oligomer are progressed.</p> |
