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 process for preparing an alkoxy-modified phenolic resole resin useful as the polyhydroxy component of a urethane binder composition. A phenol is reacted with a molar excess of an aldehyde in the presence of an alkaline catalyst and the resulting product is further reacted with a monohydric aliphatic alcohol under acidic conditions.

Abstract: A process for preparing a proppant charge comprising individual sand particles coated with a pre-cured thermosettable resin. Sand is mixed with melted resin, and the resin-coated sand is heated under conditions which cure the resin. Mixing is carried out with sufficient mechanical shearing action to limit agglomeration of the resin-coated sand particles.

Abstract: A foundry binder composition which provides foundry cores and molds of superior hot strength comprises a polyisocyanate, a polyhydroxy component and a catalyst. The polyhydroxy component is an alkoxy modified phenolic resole resin containing at least one alkoxy methylene group for every six phenolic nuclei in the resin.

Abstract: A polyisocyanate component useful in polyurethane binder compositions is provided. The polyisocyanate component incorporates organic phosphorous compounds that impart longer bench life to the binders making them more useful for prepraring moldable compositions such as foundry cores and molds.

Abstract: A suspension or solution containing an acid-curable fluoride-containing resin which is useful in a foundry process is disclosed. The fluoride-containing resin is curable at room temperatures and above by the addition of a strong acid catalyst. The resin is preferably a phenolic resole resin or a furan-type resin. The fluoride-containing resins, when used in a foundry process are preferably admixed with a foundry sand and a strong acid catalyst. The coated sand is then shaped into the form of a foundry core and is allowed to cure at room temperature or above to a foundry core having excellent tensile strength.

Abstract: A foundry core composition containing a rapid-curing furfuryl alcohol and phenolic resole resin system useful in the "hot-box" process is provided. This composition includes an acidic curing agent of low toxicity whose catalytic activity is enhanced by the presence of a water-soluble polymeric polyhydroxy compound.

Abstract: A process is provided for treating impure silica-containing sands to make them more suitable for foundry use. The sands are treated with aqueous alkali metal silicate solutions and the resulting mixture is heated before the sands are coated with a resin binder. Foundry cores and molds prepared with these treated sands show improved hot and cold tensile strengths.

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: An improved polyurethane binder system is provided which incorporates organic phosphorous compounds that impart longer bench life to the binders making them more useful for preparing moldable compositions such as foundry cores and molds.

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.

Abstract: A resin-coated sand comprising:(a) particles of sand coated with from about 1% to about 8%, by weight of the sand, of a novolak resin consisting essentially of about 50% to about 98% of a phenol-formaldehyde novolak resin and about 2% to about 50% of a catechol-formaldehyde novolak resin; and,(b) a curing agent.The sands are especially useful for forming foundry cores and molds.

Abstract: A resin-coated sand comprising:(a) particles of sand coated with from about 1% to about 8%, by weight of the sand, of a novolak resin consisting essentially of about 50% to about 98% of a phenol-formaldehyde novolak resin and about 2% to about 50% of a catechol-formaldehyde novolak resin; and,(b) a curing agent.The sands are especially useful for forming foundry cores and molds.

Abstract: There are provided binder compositions particularly useful in the foundry art which are rapid curing and which comprise (A) a phenolic resin component including at least one resole or novolak resin, solvent comprising a mixture of (1) hydrocarbon solvent and (2) polar organic solvent containing at least sufficient organic phosphate and/or carbonate ester to increase the curing speed and solubility of the phenolic resin component, (B) an isocyanate component having a functionality of two or more and (C) sufficient catalyst to catalyze substantially completely the reaction between components (A) and (B). There is also provided a moldable composition comprising aggregate material, such as foundry sand, and such binder compositions and foundry cores or molds made therefrom and including a process for their manufacture from the moldable compositions by either "cold box" or "no-bake" procedures.

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.

Abstract: A resin-coated sand comprising:(a) particles of sand coated with from about 1% to about 8%, by weight of the sand, of a novolak resin consisting essentially of about 50% to about 98% of a phenol-formaldehyde novolak resin and about 2% to about 50% of a catechol-formaldehyde novolak resin; and,(b) a curing agent.The sands are especially useful for forming foundry cores and molds.

Abstract: A resin coated sand comprising:(a) particles of sand coated with from about 1% to about 8% by weight sand of phenol-formaldehyde morolak resin;(b) a curing agent; and(c) from about 2% to about 50% by weight of phenol-formaldehyde morolak resin of an epoxy and/or phenoxy resin.The resin coated sands of the present invention provide improved thermal shock resistance without creating smoke and odor problems. In addition, the resin coated sands of the invention can be formed into foundry articles that possess good tensile strength.