Method for producing paper and cardboard
US8343311B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2009 |
| Grant date | Jan 1, 2013 |
| Priority date | — |
| Expiry date | Nov 12, 2029 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H17/68
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for producing paper, cardboard or similar materials, comprising, separately or in a mixture, adding to a fibrous suspension: at least one main retention agent comprising a cationic (co)polymer, and at least one dual retention agent comprising a crosslinked cationic (co)polymer obtained in the form of a dispersion and placed in solution prior to its introduction into the fibrous suspension with gentle stirring. The crosslinked cationic (co)polymer having—a UL viscosity of between 1.3 and 2.7 cps, preferably between 1.5 and 2.4 cps, and—an apparent cationicity ratio of between 25 and 75%. Optionally, before or after the dual agent or the main retention agent are added, one or more tertiary retention agent(s) selected from the group comprising mineral particles and organic polymers carrying anionic charges, is added to the suspension.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.