Dry strength additive for paper
US5338406A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1992 |
| Grant date | Aug 16, 1994 |
| Priority date | — |
| Expiry date | Sep 10, 2012 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H17/455
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A polyelectrolyte complex comprising at least one water-soluble, linear, high molecular weight, low charge density cationic polymer having a reduced specific viscosity greater than 2 deciliters/gram (at 0.05 weight % in a 2M NaCl solution at 30.degree. C.) and a charge density of 0.2 to 4 milliequivalents/gram (meq/g), and at least one water-soluble, anionic polymer having a charge density less than 5 meq/g, an aqueous system comprising the polyelectrolyte complex, a composition comprising the polymers which form the polyelectrolyte complex, and paper comprising the polyelectrolyte complex. It is also directed to a process comprising (1) forming an aqueous suspension of cellulosic fibers; (2) adding a strengthening additive so that the aforementioned polyelectrolyte complex is incorporated into the aqueous suspension of cellulosic fibers; and (3) sheeting and drying the fibers to form the desired cellulosic web.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.