Abstract: A foundry binder of the water-soluble alkali metal polyacrylate type having additives that include lime is cured by the use of the vapour of a low-boiling point organic ester having not more than three carbon atoms, primarily methyl formate, entrained in a carrier gas, e.g. carbon dioxide or nitrogen.

Abstract: A binder composition containing a phenolic resin, a polyisocyanate, a phosphorus based acid and optionally an acid halide and/or a base, and methods of making and using the same.

Abstract: A method of accelerating the breakdown of phenolic resin bonded cores by means of adding a basic salt of alkali metals in powder form to phenolic resin coated sand is disclosed. The basic salt is selected from the group consisting of alkali metal carbonates, bicarbonates and organic acid salts, and mixtures thereof, and is microcapsulated with plastic.

Abstract: A binder containing a phenolic resin; a polyisocyanate; a curing component, and a phosphorus halide and use thereof.

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: In combination, a binder for a foundry aggregate and a hardener therefor, as the binder, polyvinylammonium phosphate and, as the hardener, a linear alkali polyphosphate, ammonium polyphosphate, a source of polyvalent metal cations, orthophosphoric acid, or mixtures thereof.

Abstract: A binder composition for a foundry aggregate and a hardener therefor, as the binder, polyvinylammonium phosphate and, as the hardener, a linear alkali polyphosphate, ammonium polyphosphate, a source of polyvalent metal cations, orthophosphoric acid, or mixtures thereof.

Abstract: A catalyst composition and a foundry method for the rapid production of cured, high tensile strength foundry sand shapes from a foundry mixture containing a furan-based binder and polyvinyl alcohol are disclosed. The polyvinyl alcohol is incorporated into a special thermally-activated strong acid salt catalyst prior to admixture of the catalyst composition with the sand and a furan-based binder. The sand-binder-catalyst composition is then shaped and the sand shapes are heated, resulting in exceptionally high tensile strengths in short times. In foundry methods involving in situ heating of the sand shape within the pattern, clean release (without sticking) from the pattern after cure is achieved.

Abstract: A hydrogen peroxide system or composition for use in resin polymerization comprises a mixture of a major part of concentrated (70%) hydrogen peroxide admixed with minor amounts of phosphoric acid, a halo-substituted acid, such as hydrochloric acid, fluoboric acid or hydrofluoric acid, and sodium perborate. The peroxide composition is characterized by its storage stability, resistance to detonation, zero flammability, ease of handling and improved catalytic properties in the polymerization of certain resins. This hydrogen peroxide composition is compatible for use with a variety of organic peroxides which have been used for resin condensation polymerization and may be used in conjunction therewith. This hydrogen peroxide composition may be safely mixed with resins and resin prepolymers on the sand prior to use.

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: Sand cores containing an acid curable binding agent are used in the production of die castings having undercut regions because of the favorable combination of shakeout properties, resistance to washout, and resistance to surface penetration.

Abstract: A fast curing shell molding composition having the tensile strength of a conventional novolac resin when cured contains a fast curing novolac resin comprising a methylene chained polyphenylol wherein a major portion of the methylene linkages are coupled to adjacent phenylol groups of the o-o' and p-p' position, wherein at least about 19% of the methylene linkages are coupled to adjacent phenylol groups at the o-o' portions, and wherein at least about 3% of the total number of methylene linkages are coupled to adjacent phenylol groups at the p-p' positions. The shell molding composition is produced from the fast curing novolac resin by uniformly coating refractory granules with the fast curing resin. The fast curing novolac resin can be prepared by blending a conventional novolac resin with a novolac resin having a large proportion of methylene linkages coupled to adjacent phenylol groups at the o-o' position.

Abstract: In-situ formation of metal sulfonate curing agents for foundry sand binders.

Abstract: The invention relates to improvements of RCS and casting molds therefrom. The improvement resides that the resinous coating contains halogen-containing compound(s) which accelerate(s) carburizing of the resin during under heat subjected to the molten metal pouring step. Further, the resin coating comprises certain amount of pulverized metal capable of reacting under heat with separated halogen or halogen compound during the casting step and for avoiding ferrous element(s) in the castings and/or the mold(s).

Abstract: A binder composition for making molded products in conjunction with an aggregate includes in admixture a resin component comprising an organic solvent solution of a non-aqueous phenolic resin, a hardener component comprising a liquid polyisocyanate containing at least two isocyanate groups, the resin component and hardener component being curable by a curing agent, and an additional component comprising an oil-soluble phenolic resin dissolved in a drying oil and partially cross-linked therewith.

Abstract: A novel process for preparing foundry cores or molds and binder materials used therefor are provided. The binder materials comprise (a) an alcohol-soluble phenolic resin, (b) a polyvalent metal hydroxide and/or oxide, (c) water, (d) an organic solvent, and (e) an alkali metal hydroxide. They are admixed with refractory particles, such as sand, and cured with carbon dioxide to form shaped foundry cores or molds. The process and materials of the invention bring about such advantages that curing may be performed with safe carbon dioxide, that shaped foundry cores or molds may be taken out from pattern immediately after curing, and that the products have a superior collapsibility after pouring a molten metal.

Abstract: A phenolic resin binder useful for hot coating foundry sand and comprising a mixture of a solid resol phenolic resin and a lubricant is provided in the form of beads or rods of diameter of about 0.5 to 7 mm and a length of about 0.5 to 30 mm. The beads or rods can be formed directly from a molten mixture of the components or the molten mixture can first be solidified and thereafter formed into such beads or rods. The process for the hot coating of foundry sand with the phenolic resin binder and the resulting foundry compositions, molds and cores are also disclosed.

Abstract: A heat-coalescible graphitic aggregate for making graphite molds, graphite uel elements or moderating elements for nuclear reactors, and so on, is made by first forming a suspension of carbon particles in an alkaline solution of phenolformaldehyde. The suspension is then mixed together with acidulated water, the latter being heated to 40.degree. to 70.degree. C. to accelerate the reaction, with violent mixing, as in a jet device, causing a skin of insoluble phenolformaldehyde to be applied as a coating to each of the particles in suspension, which particles readily settle out and are soon separated by decanting and filtration, after which the composite solid is dried and the aqueous liquid is neutralized before being discarded.

Abstract: A process of coating sand with a phenolformaldehyde resin to produce a shell sand for use in shell molds and cores. The process comprises the steps of reacting phenol and formaldehyde at an elevated temperature to produce hot liquid phenolformaldehyde resin as a reaction product, transferring the hot liquid phenolformaldehyde resin to a mixing station while maintaining the resin at an elevated temperature to prevent solidification of the hot reaction product, mixing the hot liquid phenolformaldehyde resin with preheated sand at the mixing station to coat the sand with the resin, and cooling the coated sand to solidify the resin. When the phenol and formaldehyde are reacted at a location remote from the mixing station, the hot liquid phenolformaldehyde resin is transferred from the reaction station to the mixing station in insulated containers. The liquid resin is preferably maintained at a temperature of at least 250.degree. F. until it is mixed with the preheated sand.

Abstract: A refractory suspension comprising (parts by weight): coke, 10-60; powdered metallic titanium or/and zirconium, +0.3-5.0; resol resins, 5-50; a hardener, such as an inorganic acid, 2-30; an organic solvent, 20-60.The proposed suspension allows making foundry moulds exhibiting a higher strength. The castings produced in said foundry moulds are superior in accuracy by 2 classes, according to the USSR classification, to those obtained by the prior-art methods.