Resin composition for forming a phase-separated structure, and method of producing structure containing phase-separated structure

A resin composition for forming a phase-separated structure, including: a block copolymer, and an ion liquid containing a compound (IL) having a cation moiety and an anion moiety, the energy of the LUMO of the cation moiety being −4.5 eV or more, and the energy difference between the LUMO and the HOMO of the cation moiety being 10.0 ev or more, or the Log P value of the anion moiety being 1 to 3