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US 4,378,996 AGranted
Method for preparing binder for refractory powders
AssigneeClino Foundry Supplies Limited
InventorDennis Yarwood
Life of this patent
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Abstract
A method for preparing a hybrid binding liquid comprises coloidal silica derived from the hydrolysis of an alkyl silicate and from an acidic organo-aqueous silica sol. More than 50% by weight of silica is derived from the sol by the expedient of replacing part of the water in a commercially available silica sol either by a polyhydric alcohol or by silica.
Claims7
A method of preparing a binding liquid comprising the steps of:
- mixing an aqueous acidified silica sol having a silica content of at least 60% with an unhydrolysed alkyl silicate and a mutual solvent for water and the alkyl silicate, the sol containing water in a substantially stoichiometric amount sufficient to hydrolyse the alkyl silicate, thereby providing a binding liquid substantially free of water and with at least 50% by weight of the total silicate present being derived from the sol.
Dependencies are inferred from the claim text.