MOLDING MATERIAL AND CASTING MOLD

摘要

PURPOSE:To decrease the amt. of the stimulative gas to be generated and to improve the collapsing property of a casting mold by mixing molding sand coated with a thermosetting resin and hydrous magnesium silicate type clay ore and forming a shell mold material. CONSTITUTION:The thermosetting resin 1 such as novolak type phenolic resin or resol type phenolic resin is coated at a ratio of 1-10wt% or the like by a hot coating method, etc. on molding sand 2 such as silica sand or zircon sand. Further the thermosetting resin 1 is similarly coated on the hydrous magnesium silicate type clay ore 3 which is then mixed with the molding sand 2 coated with the thermosetting resin 1 to form the shell mold material. The fine pores constituting the clay ore 3 absorbs the stimulative gas in the stage of forming the casting mold and casting and accelerates the decomposition of the resin 1 as a catalyst in the stage of casting and heating. The amt. of the stimulative gas to be generated is thus decreased and the collapsing property of the casting mold is improved.