Patent ID: 6509392
Filing Date: 2003-01-21
Classification: B22C

Abstract:
A no-bake foundry mix for producing foundry shapes comprising:a major amount of a foundry aggregate and a minor amount of binder, said binder comprising: (a) a polyol component comprising a polyether polyol; (b) a polyisocyanate component, said polyisocyanate component providing isocyanate groups in a stoichiometric excess of the amount required to react with the hydroxyl groups of said polyol component wherein the stoichiometric ratio of the isocyanate groups in said polyisocyanate component to the hydroxyl groups in said polyol component is greater than 2:1 and no greater than about 10:1; and (c) a catalyst component comprising a catalyst that promotes the trimerization of isocyanates to form isocyanurates, said catalyst being present in an amount effective to cause trimerization of a portion of said polyisocyanate component to form isocyanurates.