초록

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.

대표청구항 ▼

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

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 [Figure] wherein R1, R2, and R3 independently are hydrogen, alkyl having from 1 to 6 carbon atoms, or －(CH2)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.