Patent ID: 8420770

Claim:
An inkjet ink, comprising: a polyamic acid (A) having a weight-average molecular weight of 50,000-500,000 and a structural unit of Formula (1) below prepared from at least a compound (a1) having two or more anhydride groups and a diamine (a2); at least one selected from the group consisting of an amic acid compound (B1) prepared from a compound (a3) having two or more anhydride groups and a monoamine (a5), and an amic acid compound (B2) prepared from a diamine (a4) and a compound (a6) having one anhydride group; and a solvent (C), wherein in Formula (1), R 1 and R 2 are each independently an organic group having 2-100 carbon atoms, wherein the inkjet ink comprises 0.5 wt %-4 wt % of the polyamic acid (A), 15 wt %-50 wt % of the amic acid compound (B1) and the amic acid compound (B2) in total, and 46 wt %-84.5 wt % of the solvent (C).