A coating resin composition for forming a coating film, comprising: a cyclic ether group-containing polymer (A) which is a polymer of a polymerizable monomer component (a) containing an ethylene-based unsaturated monomer (a11) having a cyclic ether group and an ethylene-based unsaturated monomer (a12) not having a cyclic ether group, wherein the polymerizable monomer component (a) contains only monomers containing 11 or less carbon atoms; and a component (B) consisting of at least one compound selected from a group consisting of a polycarboxylic acid (b 1) and a polycarboxylic acid anhydride (b2), wherein in a case where the component (B) contains the polycarboxylic acid (b1), the polycarboxylic acid (b1) contains at least one of 4-methylhexahydrophthalic acid and hexahydrophthalic acid, in a case where the component (B) contains the polycarboxylic acid anhydride (b2), the polycarboxylic acid anhydride (b2) contains at least one of 4-methylhexahydrophthalic anhydride and hexahydrophthalic anhydride, an amount of the cyclic ether groups in the cyclic ether group-containing polymer (A) is larger than or equal to 0.1 equivalents and less than or equal to 16 equivalents, with respect to 1 equivalent of the carboxyl groups in the component (B), a cured product of the coating resin composition which is cured by being heated for 0.1 hour or more at a temperature higher than or equal to 100 °C and lower than or equal to a decomposition temperature of the coating resin composition has a water contact angle of 90° or less under a measurement specified by JIS R3257, the monomer (a12) is selected from the group consisting of tert-butyl acrylate and tert-butyl methacrylate, and an amount of the ethylene-based unsaturated monomer (a11) is larger than or equal to 40 parts by mass and less than 100 parts by mass, with respect to 100 parts by mass of the polymerizable monomer component (a). a cyclic ether group-containing polymer (A) which is a polymer of a polymerizable monomer component (a) containing an ethylene-based unsaturated monomer (a11) having a cyclic ether group and an ethylene-based unsaturated monomer (a12) not having a cyclic ether group, wherein the polymerizable monomer component (a) contains only monomers containing 11 or less carbon atoms; and a component (B) consisting of at least one compound selected from a group consisting of a polycarboxylic acid (b 1) and a polycarboxylic acid anhydride (b2), wherein in a case where the component (B) contains the polycarboxylic acid (b1), the polycarboxylic acid (b1) contains at least one of 4-methylhexahydrophthalic acid and hexahydrophthalic acid, in a case where the component (B) contains the polycarboxylic acid anhydride (b2), the polycarboxylic acid anhydride (b2) contains at least one of 4-methylhexahydrophthalic anhydride and hexahydrophthalic anhydride, an amount of the cyclic ether groups in the cyclic ether group-containing polymer (A) is larger than or equal to 0.1 equivalents and less than or equal to 16 equivalents, with respect to 1 equivalent of the carboxyl groups in the component (B), a cured product of the coating resin composition which is cured by being heated for 0.1 hour or more at a temperature higher than or equal to 100 °C and lower than or equal to a decomposition temperature of the coating resin composition has a water contact angle of 90° or less under a measurement specified by JIS R3257, the monomer (a12) is selected from the group consisting of tert-butyl acrylate and tert-butyl methacrylate, and an amount of the ethylene-based unsaturated monomer (a11) is larger than or equal to 40 parts by mass and less than 100 parts by mass, with respect to 100 parts by mass of the polymerizable monomer component (a). <EOS>