PHENOLIC RESINS

摘要

A cured phenolic resin may be prepared by reacting (1) an esterified phenolic compound containing one or more phenolic hydroxyl groups and/or one or more esterified phenolic hydroxyl groups and further containing one or more esterified methylol groups positioned ortho and/or para to a phenolic hydroxyl group or esterified phenolic hydroxyl group with (2) a phenolic novolak resin in the presence of a base and water or other polar solvent. The invention is particularly useful for the production of foundry moulds or cores wherein the above composition is used as a binder for a granular refractory material such as sand.