POLYURETHANE-FORMING FOUNDRY BINDERS AND THEIR USE

摘要

This invention relates to no-bake foundry binders and a no-bake process for preparing foundry shapes which utilizes polyurethane-forming foundry binders. The binders are unique because the isocyanate component preferably contains no solvent and the weight ratio of the phenolic resin component to isocyanate component is atypical. It has been found that the use of these binders in a no-bake process produces foundry shapes with improved tensile strengths.