Abstract: An optical forming apparatus which can form a homogeneous three-dimensional object exhibiting desired properties over all parts, while effectively suppressing sedimentation of filler even though the filler is easily precipitated in a photo-curable resin composition. The optical forming apparatus can produce a three-dimensional object consisting of laminated layers of cured resin produced by repetition of forming cured resin layers by selectively irradiating a photo-curable liquid resin composition placed in a container (20), wherein the apparatus is characterized by having a means (60) for circulating the photo-curable liquid resin composition.

Abstract: A photo-curable resin composition suitable as a material for photo-fabricating and capable of producing cured products with excellent mechanical strength and high heat resistance. Further disclosed is a process for molding a resin-based mold which provides superior molding dimensional precision and superb repetition durability. The resin composition contains a monomer component containing (A) 30-70 wt % of a polyfunctional unsaturated monomer having a cyclic structure and (B) 70-30 wt % of a monofunctional unsaturated monomer having a cyclic structure of which the homopolymer has a glass transition temperature (Tg) of 70.degree. C. or higher; (C) a photo-initiator; and (D) an inorganic filler having an average particle diameter or an average fiber length of 1-50 .mu.

Abstract: A photo-curable resin composition suitable as a material for optical molding. The composition can produce cured products with excellent mechanical strength and high heat resistance. Further disclosed is a process for molding a resin-based mold which provides superior molding dimensional precision and superb repetition durability. The composition contains a monomer component which contains (A) 20-80 wt % of a urethane-bond polyfunctional (meth)acrylate having a number average molecular weight of 1,000 or less and (B) 80-20 wt % of an ethylenically unsaturated monomer containing a cyclic structure and at least one ethylenically unsaturated bond in the molecule and of which the homopolymer has a glass transition temperature of 50.degree. C. or higher; (C) a photopolymerization initiator; and (D) an inorganic filler having an average particle diameter or an average fiber length of 1-50 .mu.