Preparation of water-soluble copolymers containing vinylamine units, and their use as wet strength agents and dry strength agents for paper
US4774285A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1986 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Sep 15, 2006 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/18
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Water-soluble copolymers containing copolymerized vinylamine units are prepared by copolymerizing (a) from 95 to 10 mol % of N-vinylformamide and (b) from 5 to 90 mol % of an ethylenically unsaturated monomer from the group consisting of vinyl acetate, vinyl propionate, C.sub.1 -C.sub.4 -alkyl vinyl ethers, the esters, nitriles and amides of acrylic acid and methacrylic acid and N-vinylpyrrolidone, and then eliminating from 30 to 100 mol % of the formyl groups from the copolymer. Preferred copolymers are copolymers of N-vinylformamide and vinyl acetate, in which from 30 to 100 mol % of the monomer units are hydrolyzed. The copolymers are used in papermaking to increase the dry strength and wet strength of the paper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.