PURPOSE: To provide the subject solution capable of providing a baking paint improved in flexibility and secondary working adaptability consisting of an epoxy-contained compound containing adjacent epoxy groups, a phosphor- contained compound consisting of (per)phosphoric acid, and an organic solvent.

CONSTITUTION: This composition contains (A) a product obtained by reacting (i) an epoxy group-contained compound containing one or more adjacent epoxy groups on the average per molecule with (ii) a phosphor-contained compound consisting of phosphoric acid and/or perphosphoric acid in a mole ratio of component (ii):(i) of (0.02:1)-(5:1), and (B) a mixture of an organic solvent for the component A. The component A is used in 100-10 wt.% to the components A+B, and the component B is used in 10-90 wt.%.