| 摘要 |
PURPOSE:To provide a binder and the producing method without generating a gas when a melten metal is poured, capable of preventing the casting defects such as blowholes, thinning the cast steel, etc., obviating the deterioration of the physical properties in the case of cast steel and attaining good dimensional precision, capable of being utilized in casting from light alloy to cast steel and capable of adjusting the strength of the core and improving the collapsibility. CONSTITUTION:A crude formed article is formed with an aggregate and a first binder. The crude formed article is impregnated with a second binder consisting of an alcohol soln. contg. one or >=2 kinds of metal alkoxides selected from group IVA or IVB (except carbon) metal alkoxides, group IIIA or IIIB metal alkoxides and their partial hydrolyzate and the compds. of alkali metals and alkaline-earth metals (one or >=2 kinds of mixtures selected from metal alkoxides, metal hydroxides or their salts) and hydrolyzed. The crude formed article is dried and then fired at a high temp. |
