The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 29, 2013
Filed:
Jul. 10, 2009
Marek Tokarz, Göteborg, SE;
Hans-åke Baltsen, Varberg, SE;
Marek Tokarz, Göteborg, SE;
Hans-Åke Baltsen, Varberg, SE;
Akzo Nobel N.V., Arnhem, NL;
Abstract
The present invention relates to a silica-based sol having a concentration of soluble silica of less than about 1000 mg SiO/l, conductivity of at least about 2.0 mS/cm and S-value below about 50%. The invention further relates to a method of producing a silica-based sol comprising subjecting an aqueous alkali metal silicate solution to electrodialysis to form an electrodialyzed sol, and acidifying the electrodialyzed sol to form an acidified sol having a pH in the range of from about 5.0 to about 10. The invention further relates to silica-based sol obtainable by the process and to the use of the silica-based sol as a flocculating agent. The invention further relates to a process for producing paper which comprises providing an aqueous suspension comprising cellulosic fibers, adding to the suspension one or more drainage and retention aids comprising a silica-based sol according to the invention, and dewatering the obtained suspension to provide a sheet or web of paper.