Disintegration assistant for casting molds
AssigneeNissan Motor Co., Ltd.
InventorsKeizi Ohashi, Kazuo Takahashi
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Abstract
A disintegration assistant is added to a molding composition made up of foundry sand and a binder whose major part is a condensation-reactive compound or resin having methylol groups in a molecule. The molding composition is formed into a mold and a core by solidifying the resin so that individual grains of the foundry sand are bound each other. The disintegration assistant is mainly made of calcium hydroxide, calcium carbonate, barium hydroxide and/or barium carbonate, thereby promoting the heat deterioration of the resin to improve the disintegration characteristics of the mold and the core.
Claims6
A molding composition for forming a mold and a core for casting, said molding composition comprising foundry sand, a binder for binding said foundry sand, said binder including as a major part a condensation-reactive compound having at least one methylol group in a molecule, a disintegration assistant for improving disintegration characteristics of the mold and the core produced by binding said foundry sand with said binder, said disintegration assistant including at least one compound selected from the group consisting of calcium hydroxide, calcium carbonate, barium hydroxide, and barium carbonate, and a compound capable of generating gas upon heating at a temperature ranging from about 200.degree. to about 400.degree. C.
Dependencies are inferred from the claim text.