Urethane binder compositions for no-bake and cold box foundry application utilizing isocyanato-urethane polymers
AssigneeAshland Oil, Inc.
InventorsRalph D. Martin, William R. Dunnavant, Gregory P. Sturtz, Heimo J. Langer
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Abstract
Foundry cores and molds for casting metals are prepared by forming a binder comprising a polyol, an isocyanato urethane polymer and a urethane catalyst. The foundry cores and molds of this invention are formed by processes known in the industry as the "cold box" process and the no-bake process. The binder is especially useful for casting non-ferrous metals, for example, the casting of aluminum, magnesium and other lightweight metals. The cores and molds produced for casting aluminum and other lightweight metals exhibit excellent shakeout while retaining other desirable core and mold properties.
Claims24
A binder composition useful for making shaped foundry articles for use in casting lightweight metals, which articles collapse after casting of said lightweight metals, comprising in admixture a polyol component, an isocyanate component comprising an isocyanato urethane polymer wherein all hydroxy groups of said polymer are capped and a curing agent.
Process of forming shaped foundry articles for use in casting lightweight metals, which articles collapse after casting of said lightweight metals, comprising:
- (a) Forming a foundry mix by distributing on an aggregate a binding amount of up to 10%, based upon the weight of the aggregate, of a binder composition, said composition comprising in admixture a polyol component and an isocyanate component, said isocyanate component comprising an isocyanato urethane polymer wherein all hydroxy groups of said polymer are capped.
- (b) Shaping the foundry mix into a desired foundry article;
- and
- (c) Contacting the shaped foundry mix with a tertiary amine which is gaseous at room temperature until the binder has cured.
Process of forming shaped foundry articles for use in casting lightweight metals, which articles collapse after casting of said lightweight metals, comprising:
- (a) Forming a foundry mix by distributing on an aggregate a binding amount of up to 10%, based upon the weight of the aggregate, of a binder composition, said composition comprising in admixture a polyol component and an isocyanate component, and a curing agent, said isocyanate component comprising an isocyanato urethane polymer wherein all hydroxy groups of said polymer are capped.
- (b) Shaping the foundry mix into a desired foundry article;
- and
- (c) Allowing the article to cure.
Dependencies are inferred from the claim text.