Silica-based sols and their production and use
2 2A process for producing an aqueous silica-based sol is disclosed wherein a cationic ion exchange resin having part of its ion exchange capacity in hydrogen form is contacted with an aqueous alkali metal silicate to form a slurry having a pH from 5.0 to 11.5 and/or having particle aggregation or m...
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Main Authors | , |
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Format | Patent |
Language | English |
Published |
03.04.2012
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Online Access | Get full text |
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Summary: | 2 2A process for producing an aqueous silica-based sol is disclosed wherein a cationic ion exchange resin having part of its ion exchange capacity in hydrogen form is contacted with an aqueous alkali metal silicate to form a slurry having a pH from 5.0 to 11.5 and/or having particle aggregation or microgel formation corresponding to a S value up to 45%; adjusting the pH using a material comprising an aluminum compound; and separating the resin from the slurry.Silica-based sols having an S value from 15 to 25%, mole ratio Si:Al from 20:1 to 50:1, mole ratio Si:X, where X=alkali metal, from 5:1 to 17:1, SiOcontent of at least 5% by weight and containing silica-based particles having a specific surface area of at least 300 m/g, as well as the use of such silica-based sols in producing paper are disclosed. |
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