Abstract: No-bake foundry binders that produce foundry shapes with improved hot strength are provided. The binder comprises a polyether polyol component, a polyisocyanate component and a catalyst component that promotes the trimerization of polyisocyanates to polyisocyanurates. Supplemental catalysts that promote the reaction of the isocyanate with the polyols may also be used. Foundry mixes are prepared by mixing the binder with a foundry aggregate and making foundry shapes using the no-bake process.

Abstract: No-bake inorganic binder compositions for binding particulate material and methods for curing such inorganic binders. The inorganic binder compositions are composed of silicate and phosphate components. The no-bake compositions further contain curing catalyst such as a catalyst selected from the group consisting of aliphatic carbonates, cyclic alkylene carbonates, aliphatic carboxylic acid esters, cyclic carboxylic acid esters, phosphate esters and mixtures thereof. The composition produces a binder having the advantageous strength properties of a silicate binder system with the water breakdown properties of a phosphate binder system. Thus, relative to an all-silicate binder system, the present invention has improved mechanical shakeout and improved water collapsibility. Also, relative to conventional all-phosphate binder system, the present invention has superior hot strength, i.e., the foundry cores and molds do not soften at elevated temperatures.

Abstract: A curable, alkaline, melamine modified phenol-formaldehyde resin is prepared from an initial phenol-formaldehyde resole resin containing from 0.5 to 2.5 percent of free formaldehyde by scavenging formaldehyde with 1 to 12 parts of melamine for each 100 parts of the initial resin wherein the molar ratio of formaldehyde to melamine is 0.2 to 1.5 moles of formaldehyde for each mole of melamine to reduce the free formaldehyde to less than 70% of that in the initial resin and prepare a storage stable resin which contains less than 0.7% of free formaldehyde and which maintains its stability under application conditions. An ammonium salt of strong acid and additional water is incorporated in the melamine modified resin to prepare an alkaline binder. The binder is sprayed on to fiberglass with low formaldehyde emissions, good stability and rapid cure in the acid range.

Abstract: Proppants comprising a particle coated with a composition comprising bisphenol-aldehyde novolak resin, a bisphenol homopolymer or mixtures including such polymers are disclosed. Foundry sands comprising a particle coated with a composition comprising bisphenol-aldehyde novolak resin, a bisphenol homopolymer or mixtures including such polymers are disclosed. Methods of making and using these proppant particles in subterranean formations or making and using these foundry sands in foundries are also disclosed.

Abstract: There is provided a composition that is the product of mixing and reaction a resole, an alcoholate of an amino triazine, and aldehyde. This composition is useful as a thermosetting resin. This composition is useful as a curative for novolac resins. There is also provided a process for making this composition. In particular there is a process disclosed for making this composition in aqueous solution. Furthermore, curable novolac compositions, and processes for making these compositions, are disclosed and claimed.

Abstract: Proppants comprising a particle coated with a composition comprising bisphenol-aldehyde novolak resin, a bisphenol homopolymer or mixtures including such polymers are disclosed. Foundry sands comprising a particle coated with a composition comprising bisphenol-aldehyde novolak resin, a bisphenol homopolymer or mixtures including such polymers are disclosed. Methods of making and using these proppant particles in subterranean formations or making and using these foundry sands in foundries are also disclosed.

Abstract: A phenolic resole resin for use as a foundry binder which has been internally modified to reduce its hot strength and thereby enhance its shakeout property is disclosed. The resin is the reaction product of a phenolic compound; a dialdehyde; and formaldehyde. A process of preparing such resin is also disclosed, comprising first reacting the phenolic compound and the dialdehyde, and subsequently reacting the product with the formaldehyde. The resin may be, in a preferred embodiment, an ester-curable alkaline phenolic resin. Also disclosed are a raw batch formulation including the resin of the invention, and foundry articles prepared therefrom.

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: Sand cores are removed from metal or plastic coatings by exposing the cores to a humid atmosphere for a sufficient time to weaken the binder of the sand cores. The sand is then shaken from the casting. Metal or plastic castings with hollow passages are produced by forming a casting around the sand core bound with a suitable binder followed by exposing the casting and sand core to a humid atmosphere and then shaking the sand from the casting.

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 process for improving the flowability of resin coated sand which comprises the use of a flow promoter with the mixture of sand and resin. Also provided is a foundry mix comprising foundry sand, a resin binder and the flow promoter, as well as a process for making foundry cores and molds using the foundry mix. The resins are ester-curable alkaline phenolic resole resins. The flow promoter is selected from the group consisting of fatty acids, fatty alcohols, fatty amines, fatty amides and fatty alkanolamides.

Abstract: A process for improving the flowability of resin coated sand which comprises the use of a fluorosurfactant with the mixture of sand and resin. Also provided is a resin binder containing a fluorosurfactant and a foundry mix comprising foundry sand, a resin binder and a fluorosurfactant. The resins used are alkaline phenolic resole resins and acid-curable resins.

Abstract: A foundry shell core and mold composition comprises particulate matter coated with a curable phenolic-furan resin. The process for making the resin coated particulate matter substantially eliminates the sue of hexamethylene tetramine.

Abstract: An improved process is provided for preparing a product containing particles individually coated with a cured, thermoset phenolic resin. The process comprises mixing particulate matter with an uncured resin and a lubricant at a temperature which causes curing of the resin. The product obtained by this process shows superior properties as a propping agent for treating subterranean formations.

Abstract: Shell process foundry resin compositions containing novolak resins are improved by incorporating therein from about 0.5 to about 10 percent, based on the weight of the resin, of a finely divided, siliceous material such as fumed silica, bentonite, kaolin clay and attapulgus clay. The presence of the siliceous material provides resistance to peelback during the formation of sand shells and increases the stripping strengths of the incompletely cured molds.