RESIN-COATED SAND FOR MULTILAYERED CASTING MOLD

摘要

To provide resin-coated sand for a multilayer mold in which the consolidation strength of the casting mold obtained by using it and gas permeability thereof are improved at the same time, the amount of occurrence of pyrolytic products (tar, soot and the like) derived from organic substances is effectively inhibited, when molding is performed using such a casting mold, and further, the casting mold after molding can exhibit excellent collapsibility. Disclosed is resin-coated sand for a multilayer mold, in which surfaces of refractory particles are coated with a binder composition containing a phenolic novolak resin having an ortho/para bond ratio of methylene groups of 1.5 or more and an aromatic amine as indispensable constituents, and the grain fineness number is from 80 to 150.