Method for integrally forming resin model

A method for integrally forming a resin model with a complicated shape and a complicated hollow portion inside thereof:

• a process for combining foamed polystyrene fine particles (C) to two-component reaction curing type soft urethane liquid resin (A), injecting a resulting mixture into a mold for core (C) with a concave portion corresponding to said hollow portion, hardening it, removing a resulting cured matter from said mold for core (C), and forming a vanishing core (D) having a shape corresponding to said hollow portion;
• a process for setting said vanishing core (D) at a specific position inside a mold for resin model (E) having a concave portion corresponding to an outer shape of said resin model, injecting two-component reaction fast curing type urethane liquid resin (F), hardening it, removing a resulting cured matter, and forming a resin model (G) including said vanishing core (D);
• and
• a process for injecting organic solvent capable of dissolving foamed polystyrene (H) into said vanishing core (D of said resin model (G) to dissolve said foamed polystyrene fine particles (B), removing a resulting solution, taking out and removing a cured matter (I) of said two-component reaction curing type soft urethane liquid resin (A), and completing said resin model.