| 摘要 |
<p>An embodiment of the present invention provides a method for improving the tensile strength of foundry cores and molds over what may be conventionally achieved. The use of acidic methylene compounds in binder compositions which include strongly alkaline phenolic resoles results in an ester curable binder that may be used to make foundry cores and molds having significantly greater tensile strengths than are achieved with prior art binders. An embodiment of the present invention provides a composition which includes a phenolic resole having a pH ranging from about 10.5 to about 13.5 and an acidic methylene compound.</p> |
