Foseco International Limited

Co-operative Verkoap-en Productievereiniging Van Aardappelmeel En

Raymond D George

John Stevenson

Sidney A Barker

Martin Bradley

Neil Baggett

David R De Courcy

Timothy Hammond

Andries Kraak

A binder composition for producing articles of bonded particulate material such as foundry moulds or cores comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.

Production of articles of bonded particulate material and binder

A binder composition for producing articles of bonded particulate material such as foundry moulds or cones comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.

The invention relates to alkali metal silicate binder compositions, particularly for use in the production of foundry moulds and cores. The binders of the invention are in aqueous solution and are obtained by mixing:

Alkali metal silicate binder compositions

The breakdown properties of silicate bonded foundry sand moulds and cores can be improved by including with the silicate binder a starch hydrolysate having a dextrose equivalent of less than 5.

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Sutton Coldfield, United Kingdom

Raymond D George