A foundry binder comprising one or more cycloalkanes as a solvent

Abstract

A foundry binder comprising (a) a polyol component selected from the group consisting of phenolic resins, polyether polyols, polyester polyols, aminopolyols, and mixtures thereof, and (b) a polyisocyanate component, wherein component (a) and / or (b) further comprise, as a solvent, one or more cycloalkanes.

Description

[0001] related application [0002] This application claims priority to US Provisional Patent Application Serial No. 61 / 266,036, filed July 16, 2009. Background technique [0003] In the foundry industry, one of the procedures used to manufacture metal parts is "sand casting". In sand casting, disposable foundry shapes (such as molds, cores, sleeves, pouring cups, covers, etc.) are produced from a foundry mix comprising a mixture of refractory material (usually sand) and an organic or inorganic binder. [0004] Cast shapes are usually produced by the so-called no-bake, cold box and / or thermosetting methods. In the no-bake method, a liquid curing catalyst is mixed with refractory materials and binders to form a foundry mix, which is then shaped in a mold. The foundry sand mixture is shaped by compacting it in a mold and allowing it to cure until it is self-supporting. In the cold box process, a vaporous curing catalyst is passed through a forming mixture of aggregate and bin...

AI Technical Summary

Problems solved by technology

This technique also has some disadvantages such as gel formation in the acid wash solution used to reduce amine solidification gases and the white silica fines that form can deposit on castings, accumulate in used sand or in the air carrier tape

[0013] Cycloaliphatic-free solvents such as kerosene and tetradecene have been added in small amounts to polyol-polyisocyanate binders, especially phenolic polyurethane cold box and no-bake binders, but their strong nonpolar solubility leads to Greatly limit its use in binder formulations to less than 5% by weight of the combined weight of the total binder, Part I (polyol component) and Part II (polyisocyanate component)

Images