| abstract |
No-bake foundry binders that produce foundry shapes with improved hot strength are provided. The binder comprises a polyether polyol component, a polyisocyanate component and a catalyst component that promotes the trimerization of polyisocyanates to polyisocyanurates. Supplemental catalysts that promote the reaction of the isocyanate with the polyols may also be used. Foundry mixes are prepared by mixing the binder with a foundry aggregate and making foundry shapes using the no-bake process. |