摘要 |
<p>This invention relates to heat curable foundry mixes and binder compositions particularly suitable for making foundry shapes by a hot box process. The binders used are aqueous basic solutions of phenolic resole resins. Salts are added to the binders or the sand to improve the tensile strength of foundry shapes made with the foundry mixes. Silicone compounds are added to the aggregate to improve the water resistance of foundry shapes made with the foundry mixes containing the binder and salt. The foundry shapes are used to prepare metal castings.</p> |