| 摘要 |
PURPOSE:To obtain a compsn. having an excellent low-temp. collapsing property in the stage of producing the coated sand compsn. consisting of sand grains for casting coated with a phenolic resin by incorporating the salt of a specific nitrogenous org. compd. as a collapsing property assistant into said compsn. CONSTITUTION:The hydrochloride and/or hydrobromate of the nitrogenous org. compd. such as >=1 kinds amount an org. amine, melamine resin, urea resin and melamine-urea cocondensation resin which are the collapsing property assistant is incorporated into the coated sand compsn. consisting of the phenolic resin coated with the sand grains for casting in the stage of producing said compsn. The casting mold manufactured by using such coated sand compsn. maintains the prescribed strength during pouring and the collapsing property of the molding sand after casting is good not only in the case of a high pouring temp. but also in the case of producing an Al casting having the low pouring temp. |
