Silica-based sols and their production and use
US7851513B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2009 |
| Grant date | Dec 14, 2010 |
| Priority date | — |
| Expiry date | Nov 20, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S516/928
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A process for producing aqueous 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, SiO2 content of at least 5% by weight and containing silica-based particles having a specific surface area of at least 300 m2/g, are 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 aluminium compound; and separating the resin from the slurry. Further, the use of such silica-based sols in producing paper is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.