Foundry sand compositions containing graft copolymers of biochemically-synthesized heteropolysaccharides
AssigneeInternational Minerals & Chemical Corp.
InventorsWilliam J. Lang, John J. Krajewski
Life of this patent
Estimating the term…
Abstract
A sand core and mold composition for use in casting metals comprising foundry sand, clay, water and from about 0.0025% to about 1% by weight of a water-soluble graft copolymer of acrylic acid and a minor amount of a water-soluble polyhydroxy polymeric compound, including water-soluble salts thereof.
Claims16
A foundry molding composition comprising a major amount of foundry sand and minor amounts of clay, water, and a water-soluble graft copolymer, said graft copolymer being present in an amount sufficient to enhance the workability of said composition and being of the group consisting of a graft copolymerization product of acrylic acid and from about 0.1 to about 10% by weight, based on the weight of said acrylic acid, of a biochemically-synthesized heteropolysaccharide, and water-soluble salts of said graft copolymerization product, said biochemically-synthesized heteropolysaccharide containing at least about 5% free hydroxyl groups and being free of substituents other than hydroxyl groups that are reactive with acrylic acid.
A foundry molding composition from about 84 to about 96% by weight of a foundry sand, from about 3 to about 10% by weight of clay, from about 1 to about 5.5% by weight of water, and from about 0.0025 to about 1% by weight of a graft copolymer, said graft copolymer being a hydroperoxide or hydrogen peroxide-induced graft copolymerization product of acrylic acid and from about 0.25 to about 5% by weight, based on the weight of said acrylic acid, of a biochemically-synthesized heteropolysaccharide, or a water-soluble salt of said graft copolymerization product.
Dependencies are inferred from the claim text.