An object of the present invention is to provide an emulsion coagulant which can be used to quickly coagulate a tire puncture sealing material in an extremely low temperature environment. The emulsion coagulant of the present invention is an emulsion coagulant comprising: component (A) having a particle size of from 35 to 100 µm and comprising at least one type selected from the group consisting of aluminum oxide, magnesium oxide, and silicon oxide; propylene glycol alginate; and component (B) comprising at least one type selected from the group consisting of calcium oxide, calcium chloride, calcium acetate, and urea; the amount of component (B) being from 3 to 30 mass% of the total amount of component (A), propylene glycol alginate, and component (B); and the emulsion coagulant being used to coagulate a tire puncture sealing material comprising an emulsion.
