Colloidal silica/polyelectrolyte blends for pulp and paper applications
US5840158A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1997 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Apr 7, 2017 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H17/68
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for the manufacture of paper comprising the steps of: PA1 a) forming an aqueous cellulosic papermaking slurry; PA1 b) adding an effective coagulating amount of a coagulant and a flocculant to said cellulosic papermaking slurry, wherein said coagulant is prepared by blending PA2 i) an effective coagulating amount of an aqueous conditioned colloidal silica sol with an average particle size within the range of from 1 to 150 nm and wherein the aqueous colloidal silica sol is conditioned by contacting said sol with a strong acid cation exchange resin, and PA2 ii) an effective coagulating amount of a cationically-charged water-soluble polymeric coagulant; PA1 c) draining said cellulosic suspension to form a sheet; and, PA1 d) drying said sheet. The components of the invention are blended together so that addition is simultaneous. The colloidal silica is conditioned by passing over a cationic exchange resin prior to addition of cationic polymer. The term conditioned as used herein refers to the act of passing the colloidal silica over a cationic exchange resin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.