METHOD FOR PRODUCING POLYMER SOLUTION, AND POLYMER SOLUTION

摘要

A method for producing a polymer solution, comprising the following steps (a) to (d): (a) a synthesis step of reacting an amine component with an acid component in a solvent containing N-methyl-2-pyrrolidone (NMP) to produce a polymer mixture containing a polyimide precursor or a polybenzoxazole precursor; (b) a liquid separation step of adding both water or an aqueous solution and a low-boiling-point solvent to the polymer mixture, and then removing an aqueous layer from the resultant mixture by carrying out a liquid separation procedure to produce a low-boiling-point solvent layer; (c) a step of adding both a displacing solvent and a polar solvent to the low-boiling-point solvent layer; and, subsequent to step (c), (d) a concentration step of distilling the low-boiling-point solvent under a reduced pressure.