HEAT-INSULATIVE COATING COMPOSITION

PROBLEM TO BE SOLVED: To increase the efficiency of heat-insulating construction work by securing the fluidity and shortening the curing time, as the requirements of heat insulation, refractoriness, light-weight and like are satisfied. SOLUTION: The objective heat-insulative coating composition comprises the first solution of an aqueous water glass solution including an alkali metal silicate salt as a main component, and the second solution comprising an aqueous solution including a water glass-hardening agent, and an aggregate comprising a filler including inorganic foaming fine particles and foamed particle bodies of a synthetic resin is formulated to at least one of the first and second solutions. In a preferred embodiment, the foamed particle bodies made of a synthetic resin are the foamed polystyrene particles of a closed cell structure and the surface of the particles is made hydrophilic with a surface treatment agent. In the meantime, the fine foamed particles of the inorganic substance comprises silica balloons. Zinc borate is used as a hardening agent.