DIALDEHYDE MODIFIED, PHENOLIC FOUNDRY SAND CORE BINDER RESINS, PROCESSES FOR MAKING SAME, AND PROCESS FOR PREPARING FOUNDRY CORES AND MOLDS EMPLOYING SAME

摘要

A phenolic resole resin for use as a foundry binder which has been internally modified to reduce its hot strength and thereby enhance its shakeout property is disclosed. The resin is the reaction product of a phenolic compound; a dialdehyde; and formaldehyde. A process of preparing such resin is also disclosed, comprising first reacting the phenolic compound and the dialdehyde, and subsequently reacting the product with the formaldehyde. The resin may be, in a preferred embodiment, an ester-curable alkaline phenolic resin. Also disclosed are a raw batch formulation including the resin of the invention, and foundry articles prepared therefrom.