| 摘要 |
The invention aims to provide polyamic acid that can form a varnish with low viscosity and serves to produce, through curing, coat film with good mechanical characteristics and further aims to produce cured coat film with good mechanical characteristics regardless of whether the molar concentration of the acid anhydride group in the acid dianhydride monomer and that of the amino group in the multivalent amine compound or diamine compound are identical to or different from each other. This objective is met by polyamic acid including a structure as represented by chemical formula (1) given below: (In chemical formula (1), d represents an oxygen or sulfur atom and W represents an electron-withdrawing group, and R11 and R12 represent independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. |
