| abstract |
Binder systems for refractory materials used in sand casting processes, particularly two-part polyurethane-based binder systems used in cold box or no-bake processes, are metal-molds when another third part is used. There is little reaction. 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. |