Patent ID: 7431879

Claim:
A process of producing a three-dimensionally shaped object comprising: (a) a layer forming step of forming a powder material having a refractive index n 1 into a layer having a prescribed thickness; (b) a cross-sectional shape forming step of feeding an ultraviolet (UV) curable binder in a cross-sectional shape into the powder material layer formed in the foregoing step and irradiating UV rays to cure the binder, thereby forming a bound body of the powder material in the cross-sectional shape corresponding to a cut surface of a subject to be shaped cut at a certain one plane with a binding agent having a refractive index n 2 after the curing; and (c) repeating these steps successively, thereby successively laminating and forming the bound body of the powder material corresponding to a cut surface of the subject to be shaped cut at a plurality of planes, wherein (d) n 1 and n 2 satisfy the relationship of −0.1≦(n 1 −n 2 )≦0.1; (e) a volatile component of the UV curable binder after the curing with UV rays is not more than 5% by weight, wherein the ultraviolet (UV) curable binder consists essentially of a photopolymerization initiator, a polymerizable monomer and an additive for viscosity modification, wherein the additive for viscosity modification is a compound having a low viscosity and is capable of being copolymerized with the polymerizable monomer and (f) the amount (W) of the volatile component of the UV curable binder was measured by the weight method according to the following equation: W =( W 1 −W 2 )/ W 1 ×100% W 1 : Weight of the UV curable binder before curing W 2 : Weight of the UV curable binder after curing.