Patent ID: 7674423

Claim:
A process for producing a three-dimensional model, the process comprising: (a) a layer formation step of forming a layer of a synthetic organic powder material having a refractive index n 1 above a support, wherein the synthetic organic powder material comprises organic copolymer particles that are derived from at least two types of monomers, and wherein the organic copolymer particles comprise a copolymer of an aromatic vinyl compound and a (meth)acrylate ester; (b) a shape formation step of bonding the powder material layer into a predetermined shape by a binder that gives a refractive index n 2 , wherein a region to which the binder has been applied is cured by exposure to UV rays from UV irradiation; and (c) sequentially repeating the above steps; the absolute value of the difference between the refractive index n 1 of the powder material and the refractive index n 2 given by the binder being 0.1 or less, and the binder comprising two or more types of binders selected from the group consisting of at least one type of colored binder, a white binder, and a colorless transparent binder, wherein each of the colored binder, the white binder, and the colorless binder includes UV-curing compound, the two types of monomers being a monomer (a) and a monomer (b), a homopolymer of the monomer (a) having a refractive index of 1.55 to 1.75, and a homopolymer of the monomer (b) having a refractive index of 1.35 to less than 1.55, monomer (a) being the aromatic vinyl compound and monomer (b) being the (meth)acrylate ester, and the binder comprising a (meth)acrylate ester of an aliphatic polyhydric alcohol.