Patent ID: 8567481

Claim:
Binder composition for manufacturing foundry sand molds, comprising an alkali metal silicate; an alkali metal hydroxide; starch; an alkyl silicate and water, wherein said composition in weight percentage further comprises: (1) from 0.2% to 1.5% of an alkyl silicate based on the weight of sand used in the composition; (2) from 1.0% to 2.5% of a silicate/hydroxide solution/mixture based on the weight of sand used in the composition and having from 85% to 95% based on the solution/mixture being an alkali metal silicate, from 2% to 6% based on the solution/mixture being an alkali metal hydroxide, and from 4% to 8% based on the solution/mixture being water; (3) from 1.0% to 2.5% of a solution/mixture of starch in water based on the weight of sand used in the composition and having from 70% to 85% of the starch solution/mixture being water and from 15% to 30% of the starch solution/mixture being starch; and (4) from 0.5% to 2.5% of water, all the water in said composition being included within said 0.5% to 2.5% range.