Casting mould and core sand binder - contg. silicates of strong org. bases, pref. guanidine silicate

摘要

cold-hardenable binders for sand casting-moulds and -cores, used in casting Fe and light and heavy metal alloys, contain aq. solns. of water-soluble silicates of strong org. bases, esp. guanidine silicate or quat. ammonium silicates opt. mixed with water-glass or commercial water-glass binders. Binder pref. contains water-soluble guanidine silicate compsns. having wt. ratio guanidine: SiO2 0.7 : 1 to 2 : 1, which may be prepd. by reacting guanidinium hydroxide with Na silicates having wt. ratio SiO2 : Na2O 3.3 to 4. The storage properties of the binder-contg. sand mixt. are improved and moulds and cores have better decompsn. properties.