Epichlorohydrin-based polymers containing primary amino groups used as additives in papermaking
US7431799B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2005 |
| Grant date | Oct 7, 2008 |
| Priority date | — |
| Expiry date | Jul 29, 2026 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H23/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed is a method for manufacture and application of a polymeric papermaking additive, which can be used in paper manufacture as an agent for improving retention, drainage, product strength and paper machine operation. The additive according to this disclosure is a polymer of epichlorohydrin and contains primary amino groups. Under neutral or acidic conditions these primary amino groups become cationic, which assures good adsorption of the polymer onto anionic fibers and fines of pulps used for production of paper or paperboard. By adsorbing on several fibers or fines, the polymer can increase the retention of fines and fillers. Primary amino groups of this polymer can also form chemical bonds with carbonyl groups of cellulose, lignin and hemicellulose, which are especially abundant in the fibers and fines of mechanical pulps. The cross-linking of fibers and fines by chemical bonds can increase the initial strength of wet web and the strength of rewetted paper. Mechanical pulps contain high negative charge and tend to deactivate many conventional cationic polymers. Because of its high cationic charge and the ability to form chemical bonds with mechanical pulp, novel papermaking…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.