Heat curable foundry mixes and binder compositions
AssigneeAshland Oil, Inc.
InventorsSatish S. Jhaveri, William R. Dunnavant, Heimo J. Langer
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Abstract
This invention relates to heat curable foundry mixes and binder compositions particularly suitable for making foundry shapes by a hot box process. The binders used are aqueous basic solutions of phenolic resole resins. Salts are added to the binders or the sand to improve the tensile strength of foundry shapes made with the foundry mixes. Silicone compounds are added to the aggregate to improve the water resistance of foundry shapes made with the foundry mixes containing the binder and salt. The foundry shapes are used to prepare metal castings.
Claims33
A heat curable foundry mix comprising;
- a. a foundry aggregate;
- b. an effective binding amount of a binder comprising an aqueous basic solution of a phenolic resole resin wherein said aqueous basic solution has
- i. a viscosity of less than about 850 centipoise at 25.degree. C.;
- ii. a solids content of about 35 to about 75 percent by weight, said weight based upon the total weight of the basic solution;
- and
- iii. an equivalent ratio of base to phenolic compound of about 0.2:1.0 to 1.1:1.0;
- and
- c. an inorganic salt in an amount effective to increase the tensile strength of the foundry shapes prepared with said foundry mix.
The foundry mix of 2 wherein the base catalyst used to prepare the phenolic resin of the binder is selected from the group consisting of sodium hydroxide, potassium hydroxide, and mixtures thereof.
A foundry binder composition comprising:
- a. a binder comprising an aqueous basic solution of a phenolic resole resin wherein said aqueous basic solution has
- 1. a viscosity of less than about 850 centipoise at 25.degree. C.;
- 2. a solids content of about 35 to about 75 percent by weight, said weight based upon the total weight of the basic solution;
- and
- 3. an equivalent ratio of base to phenol of about 0.2:1.0 to 1.1:1.0;
- and
- b. an inorganic salt, which is compatible with the binder, in amount effective to increase the tensile strength of the foundry shapes prepared with foundry mixes made with said binder.
Dependencies are inferred from the claim text.