Acid catalysis of resin foundry binders
AssigneeCL Industries, Inc.
InventorsPatrick H. Stewart, Wayne D. Woodson
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Abstract
A method of producing sand cores or molds for foundry use involves coating the sand with a novel acid catalyst composition and adding acid-curing, condensation-type resin. A novel acid catalyst composition comprises the mixture of a sulfonic acid such as benzene sulfonic acid, toluene sulfonic acid or xylene sulfonic acid, or mixtures thereof, with 0.5-20% wt. perchloric acid. A catalyst of this composition, when admixed with foundry sand and an acid-curing condensation-type resin, is a novel composition characterized by rapid cure and high tensile strength and hardness in the resulting resin-bound sand core or mold. Sand cores or molds made using this catalyst/sand/resin composition are further characterized by low emissions of oxidizable gaseous organic constituents.
Claims6
A catalyst composition for the polymerization of acid curable condensation-type resin binders in sand cores or molds, comprising
- a mixture consisting essentially of an aromatic sulfonic acid and 0.5-20% wt. of perchloric acid.
Dependencies are inferred from the claim text.