Abstract: There are disclosed methods and compositions for retarding the ambient temperature hardening of a phenolic resole resin alone or with an aggregate when such resin is contacted with a nitroalkane and a hardening agent such as lightburned magnesium oxide, an organic ester functional hardening agent, and mixtures of lightburned magnesium oxide and an organic ester functional hardening agent in an alkaline medium. There is also disclosed a hardener composition for phenolic resole resins wherein the hardener composition consists essentially of a solution of a nitroalkane in an organic ester functional hardening agent.

Abstract: The present invention provides methods for treating reclaimed sand obtained from dismantled foundry molds and cores which contain a cured binder derived from an ester cured alkaline phenolic resin. Treatment of the reclaimed sand with a silane solution, particularly an aqueous solution, enhances the tensile strengths of foundry molds and cores produced therefrom beyond those obtained with untreated reclaimed sand. Methods for producing foundry cores and molds which incorporate such a treatment process are also provided by this invention as are raw batch formulations.

Abstract: The present invention provides a binder solution having a low solids level which provides improved tensile properties when used with reclaimed sand. This binder solution comprises an alkaline phenolic resin which is cured at ambient temperature with an ester-functional curing agent. Also provided by this invention are raw batch formulations comprising sand, a binder solution having a low solids level, and a curing agent. These raw batch formulations include embodiments wherein the low solids levels are obtained by the separate addition of a solvent. The methods for producing foundry molds and cores of this invention included those procedures wherein dilution water is used to reduce the solids contents of conventional, relatively high solids content binder solutions.

Abstract: The present invention provides methods for treating reclaimed sand obtained from dismantled foundry molds and cores which contain a cured binder derived from an ester cured alkaline phenolic resin. Treatment of the reclaimed sand with a silane solution, particularly an aqueous solution, enhances the tensile strengths of foundry molds and cores produced therefrom beyond those obtained with untreated reclaimed sand. Methods for producing foundry cores and molds which incorporate such a treatment process are also provided by this invention as are raw batch formulations.

Abstract: The present invention provides methods for treating reclaimed sand obtained from dismantled foundry molds and cores which contain residue from a cured binder of an ester-cured alkaline phenolic resin. Treatment of the reclaimed sand with a silane solution containing one or more amines, particularly an aqueous solution containing a silane and one or more amines, enhances the tensile strengths of foundry molds and cores produced therefrom relative to those obtained with untreated reclaimed sand. Methods for producing foundry cores and molds which incorporate such a treatment process are also provided by this invention, as are raw batch formulations.

Abstract: The present invention provides a binder solution having a low solids level which provides improved tensile properties when used with reclaimed sand. This binder solution comprises an alkaline phenolic resin which is cured at ambient temperature with an ester-functional curing agent. Also provided by this invention are raw batch formulations comprising sand, a binder solution having a low solids level, and a curing agent. These raw batch formulations include embodiments wherein the low solids levels are obtained by the separate addition of a solvent. The methods for producing foundry molds and cores of this invention included those procedures wherein dilution water is used to reduce the solids contents of conventional, relatively high solids content binder solutions.

Abstract: A raw batch composition for use in making a shaped article such as a foundry shape or refractory article is disclosed. The composition comprises a mixture of an aggregate material; a phenol formaldehyde novolak resin; a phenol formaldehyde resole resin; and an ester functional curing agent. A shaped article prepared from the composition and processes for making a refractory body or foundry article are also disclosed.

Abstract: A hardener composition for alkaline phenolic resole resin binders which comprises a solution of a benzylic ether resole resin in an ester. Binder compositions comprising this hardener with alkaline phenolic resole resins are further provided as are foundry molding compositions and methods for making foundry cores and molds using the molding compositions.

Abstract: A hardener composition for alkaline phenolic resole resin binders which comprises a solution of a benzylic ether resole resin in an ester. Binder compositons comprising this hardener with alkaline phenolic resole resins are further provided as are foundry molding compositions and methods for making foundry cores and molds using the molding compositions.

Abstract: An alkoxy-modified phenolic resole resin providing an improved binder for foundry cores and molds. The resin has predominantly ortho-ortho benzylic ether bridges joining the phenolic nuclei in the resin and at least one alkoxymethylene group for every 20 phenolic nuclei.

Abstract: A process for preparing modified phenolic resole resins providing improved binders for refractories and foundry cores and molds. The resins are prepared by treating a phenol with a molar excess of aldehyde in the presence of an alkaline catalyst followed by further reaction at a pH below 7 in the presence of a catalyst which promotes formation of ortho-ortho benzylic ether bridges between the phenolic nuclei.

Abstract: A process for preparing modified phenolic resole resins providing improved binders for refractories and foundry cores and molds. The resins are prepared by treating a phenol with a molar excess of aldehyde in the presence of an alkaline catalyst followed by further reaction at a pH below 7 in the presence of a catalyst which promotes formation of ortho-ortho benzylic ether bridges between the phenolic nuclei.

Abstract: Refractory shaped articles are prepared by heating refractory mixes comprised of refractory particles and an alkoxy modified phenolic resole resin having at least one alkoxy methylene group for every 20 phenolic hydroxyl groups.

Abstract: A cold-setting foundry binder composition, which provides foundry cores and molds with improved curing speed, comprising a particulate refractory material, a resin binder, an acid curing catalyst, and an accelerator. The accelerator is selected from the group: dihydroxybenzenes, derivatives of dihydroxybenzenes, trihydroxybenzenes, and their mixtures.

Abstract: A granular composition is provided that is especially useful for the preparation of foundry cores and molds. Incorporated in the composition is a novel resin binder that imparts rapid curing properties to the composition.