摘要 |
A binder system for refractory materials used in sand casting processes, especially two-part polyurethane-based binder systems used in the cold box or no bake process, has less metal-mold reaction when a separate third part is used. The third part is an alkyl silicate, such as tetraethyl orthosilicate ("TEOS"), an alkyl orthoformate, such as trimethyl orthoformate (TMOF) or triethyl orthoformate (TEOF), or combinations thereof. |