Method for producing lamination molded article, heat-sensitive gelling agent, and lamination molding composition

A method for producing an additive manufactured object, the method comprising layering a composition for additive manufacturing comprising a water-curable inorganic composition and a heat-sensitive gelling agent, and non-fluidizing the composition for additive manufacturing by heating at the time of layering and/or after layering,

• wherein the heat-sensitive gelling agent contains an aqueous medium, a polymer dispersed in the aqueous medium, and a nonionic surfactant having a cloud point of 30° C. or higher and an HLB value of 10 to 18,
• wherein the heat-sensitive gelling agent is a heat-sensitive gelling agent having a value of a1/a0 of 15 or more when, in a penetration resistance value (needle diameter=2 mm, piercing speed=30 mm/min, piercing depth=10 mm) measured after defoaming by adding 100 g of the following formulation of (1) to (5) [The amounts of (1) to (5) are in terms of solid content, and the moisture content is set to 18.5 mass %.]:
• (1) 100 parts by mass of mortar;
• (2) 1 part by mass of sodium gluconate;
• (3) 0.5 parts by mass of carboxymethyl cellulose:
• (4) 0.1 parts by mass of silicone antifoaming agent;
• and
• (5) 4.5 parts by mass of the heat-sensitive gelling agent,
• into a cylindrical container with an open top,
• a value at 17±3° C. immediately after defoaming is defined as a0 and a value at 17±3° C. after microwave heating at 600 W for 30 seconds after defoaming is defined as a1.