摘要 |
<p>This invention relates to polyurethan-forming foundry no-bake binder systems comprising a phenolic resin component and polyisocyante component. The phenolic resin component comprises a blend of (a) polyphenol resin and (b) a phenolic resole resin. The binder systems have reduced phenol and free formaldehyde due to the presence of the polyphenol resin in the phenolic resin component. Foundry shapes are made by the no-bake process and are used in making ferrous and non ferrous metal castings.</p> |