| 摘要 |
PURPOSE:To develop a compsn. for a casting mold from which the casting mold having high strength can be molded and which permits the reuse of the recovered sand after casting by adding a specific ratio each of a water soluble acrylic acid polymer, the oxide or hydroxide of a bivalent or tervalent metal, non-deliquescent hydrate metallic salt and water to molding sand and kneading the mixture. CONSTITUTION:The non-deliquescent hydrate metallic salt such as MgSo4.7H2O or ZnSO4.7H2O is mixed with 0.2-20pts.wt. water soluble acrylic polymer having 8000-60000mol.wt. (a), 0.01-15pts.wt. oxide or hydroxide of the bivalent or tervalent metal such as Mg, Al, Ca, Zn or Fe (b) and 0.5-20pts.wt. water (c) by 100pts.wt. molding sand such as silica sand and the mixture is kneaded. The materials are so compounded as to attain (equiv. number of b)/(equiv. number of carboxylic group of a)=0.15-14., (weight of c)/(weight of a)=0.3-2.0, (weight of d)/(weight of c)=0.2-2.0 and the casting mold is molded by such kneaded material. |
