Alkaline resol phenol-aldehyde resin binder compositions
AssigneeHüTtenes-Albertus Chemische Werke Gesellschaft Mit BeschräNkter Haftung
InventorsFrank Lenzen, Gerard Ladegourdie
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Abstract
This invention relates to alkaline resol phenol-aldehyde binder compositions and their use in the production of articles of bonded particulate material such as foundry moulds, foundry cores, or feeders.
Claims20
A binder composition produced by addition of polyalkylene glycol, comprising three or more alkylene glycol units, to an alkaline aqueous mixture comprising a base resol phenol-aldehyde resin and an oxyanion, wherein the oxyanion is capable of forming a stable complex with the base resin,
- wherein the amount of alkali present in the binder composition is sufficient to substantially prevent stable complex formation between the resin present in the binder composition and the oxyanion,
- wherein the polyalkylene glycol comprises polyethylene glycol having a molecular weight from 200 to 2000 in an amount that is miscible in the alkaline aqueous mixture and in an amount from 1% to 20% by weight based on the total weight of the binder composition, and
- wherein the binder composition has a molar ratio of alkali, expressed as hydroxyl ions, to phenol of from 1.0:1 to 2.5:1.
A method of enhancing the performance of binder composition comprising an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin, wherein the amount of alkali present in the solution is sufficient to substantially prevent stable complex formation between the resin and the oxyanion, and wherein the binder composition has a molar ratio of alkali, expressed as hydroxyl ions, to phenol of from 1.0:1 to 2.5:1, said method comprising:
- including a polyalkylene glycol, comprising 3 or more alkylene glycol units, in said binder composition, wherein the polyalkylene glycol comprises polyethylene glycol having a molecular weight from 200 to 2000 in an amount that is miscible in the alkaline aqueous mixture and in an amount from 1% to 20% by weight based on the total weight of the binder composition.
Dependencies are inferred from the claim text.