Method of producing polyimide resin, method of producing polyimide coating, method of producing polyamic acid solution, polyimide coating, and polyamic acid solution

A method of producing a polyimide resin, comprising obtaining a polyimide resin by heating at 180° C. a polyamic acid resulting from the reaction of a tetracarboxylic acid dianhydride component and a diamine component in a solvent comprising N,N,2-trimethylpropione amide;

• wherein the tetracarboxylic acid dianhydride component is at least one selected from the group consisting of pyromellitic acid dianhydride, 2,3,3′,4′-biphenyl tetracarboxylic acid dianhydride, and 3,3′,4,4′-benzophenone tetracarboxylic acid dianhydride;
• wherein the diamine component is at least one selected from the group consisting of p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4′-diaminodiphenylether;
• wherein the molar ratio of the diamine component to the tetracarboxylic acid component is 0.6 to 1.3;
• and
• wherein the molar ratio of the solvent to the diamine and the tetracarboxylic acid dianhydride components is 3.8 to 8.0.