METHOD FOR PRODUCING PHOTO-SETTING EXPANDED MATERIAL

PROBLEM TO BE SOLVED: To provide a method for producing a photo-setting expanded material, by which the production cost thereof can be reduced.SOLUTION: The method for producing a photo-setting expanded material includes: a mixing step in which polythiol having a plurality of thiol group, urethane prepolymer having at its terminals a plurality of functional group that activates radical addition reaction with the thiol group, and gas are mixed by mechanical foaming; a flow-casting step in which the mixed raw material is flow-casted onto a thermoplastic resin film 34; and a light irradiation step in which the flow-casted raw material is irradiated with light using a light irradiator 30, without being covered with sheet-like cover material, and is thereby set. By this method, since no acrylic raw material is contained in the photo-setting expanded material raw material, it becomes possible to employ a gas containing oxygen, i.e. air, as the gas to be mixed by mechanical foaming. Also, in the production process, it becomes possible to omit the step to cover the raw material with cover material and to simplify the production system. According to the present invention, therefore it becomes possible to achieve a reduction in production cost.