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US 4,847,309 AGranted
Method for making foundry sand containing a resin binder
AssigneeRohm Co., Ltd.
InventorsWolfgang Klesse, Heinz-Jochen Auer, Peter Quis
Life of this patent
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Abstract
Methods for making foundry sand containing a binder by combining a dried powdered carboxylated polymer, partially in its salt form, with dry or wet foundry sand free of binder.
Claims6
A method for making a molding sand containing a polymeric binder, which method comprises uniformly admixing a molding sand free of binder with a dried emulsion polymer that is redispersible in water and comprises
- (A) from 15 to 90 percent by weight of at least one unsaturated carboxylic acid of the formula ##STR11## wherein R.sub.1, R.sub.2, and R.sub.3 independently are hydrogen, alkyl having from 1 to 6 carbon atoms, or --(CH.sub.2).sub.n --COOM, M is a proton or an alkali metal, alkaline earth metal, or ammonium cation, and n is 0 or 1, said unsaturated carboxylic acids having not more than two --COOM groups in the molecule, and
- (B) from 10 to 85 percent by weight of further monomers copolymerizable with (A), from 0.5 to 50 weight percent of monomer (A) being present in its salt form wherein M is an alkali metal, alkaline earth metal, or ammonium cation.
Dependencies are inferred from the claim text.