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:
Mar. 02, 2010
Filed:
Dec. 20, 2006
Michael Persson, Västra Frölunda, SE;
Marek Tokarz, Kungälv, SE;
Maj-lis Dahlgren, Nödinge, SE;
Akzo Nobel N.V., Arnhem, NL;
Abstract
A process for the production of paper which includes the steps of providing an aqueous suspension containing cellulosic fibers, and optional fillers; adding to the suspension: (a) at least one charged organic polymer; and (b) an aqueous sol containing silica-based particles; wherein the sol has: (i) an S-value within the range of from 10 to 45%; (ii) a viscosity within the range of from 5 to 40 cP; and (iii) a molar ratio of SiOto MO, where M is alkali metal or ammonium, within the range of from 10:1 to 40:1; and (III) forming and draining the suspension on a wire. The invention is further directed to processes for making paper wherein the added sol has: (i) an S-value within the range of from 10 to 45%; (ii) a viscosity within the range of from 5 to 40 cP; and (iii) a silica content of at least 10% by weight, or wherein the added sol has: (i) an S-value within the range of from 10 to 45%; (ii) a viscosity within the range of from 7 to 25 cP; (iii) a silica content of at least 10% by weight; (iv) a molar ratio of SiOto MO, where M is alkali metal or ammonium, within the range of from 10:1 to 40:1; and (v) a pH of at least 10.6. The invention is further directed to a process for making paper wherein the added sol is modified by an aluminum-containing compound, a boron-containing compound or a mixture thereof and has: (i) an S-value within the range of from 10 to 45%; (ii) a viscosity within the range of from 5 to 40 cP; (iii) a silica content of at least 10% by weight; and (iv) a molar ratio of SiOto MO, where M being alkali metal or ammonium, within the range of from 10:1 to 40:1.