What is described are isocyanate compositions comprising β-dicarbonyl compounds and a binder system, especially for use in a process from the group consisting of polyurethane cold-box process and polyurethane no-bake process, with this isocyanate composition as polyisocyanate component.

The present disclosure includes binder systems for making foundry articles. The binder systems may comprise a humic substance-containing component that comprise lignite, an isocyanate component, and a catalyst component. The binder systems may be mixed with an aggregate (e.g., sand) for making foundry articles such as molds and cores. Also disclosed herein are methods of making foundry articles using the binder systems.

A sand additive for use in a “no bake” foundry mix composition having a polyurethane-based binder system reduces the amount of smoke emitted when molds and cores formed from the composition are exposed to molten metal, as compared to when the sand additive is not used. The sand additive comprises yellow iron oxide having the chemical formula Fe(OH).sub.3. It can also comprise at least one of red iron oxide, black iron oxide and wüstite. In such cases, the yellow iron oxide accounts for about 10 to about 40 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite, and preferably, about 20 to about 30 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite.

What is described is the use of a composition containing one or more formaldehyde scavengers for production of a coating on a main body of a mold or core for metal casting that emits formaldehyde when heated, wherein the coating forms a surface of the mold or core that comes into contact with a metal melt in the casting operation.

The present invention relates to a method of disintegrating a foundry mold comprising sand and a polyurethane binder. The present invention further relates to a method of disintegrating a foundry mold by contacting it with a composition comprising at least one carboxylic acid amide and at least one tyalkanolamine.

The subject matter of the invention is mold material mixtures for producing molds or cores for metal casting, consisting of at least one refractory base mold material, a binder and an additive based on factice. The invention also relates to a component system, a method for producing molds and cores using the mold material mixtures or the component system respectively, and to molds and cores produced by said method.

The present invention relates to the use of closed-pore microspheres of expanded perlite as a filler for producing moldings for the foundry industry, to a composition for producing moldings for the foundry industry, comprising closed-pore microspheres of expanded perlite as a filler, and a binder, the binder being selected from the group consisting of water glass, phenol-formaldehyde resins, two-component systems comprising as reactants a polyisocyanate and a polyol component containing free hydroxyl groups (OH groups), and starch, and also to moldings for the foundry industry and to a process for producing a molding for the foundry industry.

The invention relates to a method of producing an article selected from the group consisting of casting mold, core, feeder and molding compound for production of part of a casting mold, core or feeder, comprising the following steps: (S1) producing or providing in the foundry: a first component (A), comprising a first binder component (b1) of a binder system and an amount of a first mold base material and, spatially separated therefrom, a second component (B), comprising a second binder component (b2) of the binder system and an amount of a second mold base material wherein the first binder component (b1) and the second binder component (b2) are suitable for chemical reaction with one another and for curing of a mixture of the first component (A) and the second component (B), (S2) mixing by contacting the first component (A) and the second component (B) in a particular mass ratio, so as to result in a self-curing molding compound.

The present disclosure includes binder systems for making foundry articles. The binder systems may comprise a humic substance-containing component that comprise lignite, an isocyanate component, and a catalyst component. The binder systems may be mixed with an aggregate (e.g., sand) for making foundry articles such as molds and cores. Also disclosed herein are methods of making foundry articles using the binder systems.

Described is a phenolic resin composition for use in the polyurethane cold-box and/or no-bake process. The phenolic resin composition comprises an ortho-condensed phenolic resol having etherified and/or free methylol groups in a total amount of 40 to 60% by weight based on the total mass of the phenolic resin composition, free formaldehyde in an amount of less than 0.1% by weight based on the total weight of the phenolic resin composition, one or more reaction products of formaldehyde with one or more CH-acidic reactant compounds, other constituents in a total amount of at least 38% by weight, wherein the amount of water in the phenolic resin composition is not more than 1.0% by weight in each case based on the total mass of the phenolic resin composition. Also described is a two-component binder system for use in the polyurethane cold-box and/or no-bake process, a use of a CH-acidic compound as a formaldehyde scavenger for producing a phenolic resin composition for use in the polyurethane cold-box and/or no-bake process, a process for producing a phenolic resin composition, a process for producing a two-component binder system and a process for producing a feeder, a foundry mold or a foundry core from a molding material mixture and finally corresponding feeders, foundry molds and foundry cores.