| 摘要 |
A stable aqueous acidic metal oxide/silica sol which contains from 5-40% by weight SiO2, from 1-10.5% by weight of metal oxide, and a water-soluble anionic stabilizing compound selected from the group consisting of water-soluble anionic surfactants having an HLB greater than 8 and water-soluble carboxylic acid polymers with the ratio of metal oxide to water-soluble anionic stabilizing compound being within the range of 0.3:1 to 15:1. Also claimed is a composition and method of producing a stable alkaline metal oxide/aqueous colloidal silica sol which comprises the steps of: (a) forming a reaction mixture by mixing an hydrolyzable metal compound with an acidic, substantially ion-free collodial silica sol which contains at least 5% by weight of silica in the presence of an anionic water-soluble stabilizing compound from the group consisting of anionic water-soluble surfactants and water-soluble carboxylic acid polymers whereby the formation of metal oxide is substantially prevented and the amount of hydrolyzable metal compound is sufficient to produce at least 0.5% by weight of metal oxide based upon silica content; and (b) adjusting the pH of the reaction mixture between 1.5-2.5; and then (c) raising the pH of the metal oxide/silica sol obtained in step (b) with a water-soluble amine to at least 8.5 whereby a stable alkaline metal oxide/silica sol is produced.
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