Glyoxalated N-vinylamine
View Patent ↗The present invention is directed to compositions comprising a cellulose reactive functionalized polyvinylamine first adduct, compositions comprising combinations of the cellulose reactive functionalized polyvinylamine first adduct and cellulose reactive functionalized polyvinylamide second adduct, methods for preparing first adduct and second adduct blends and finally methods of increasing the wet or dry strength of paper by incorporation into the paper furnish or coating a paper or board with said adducts.
1. A paper or board comprising a blend of a first cellulose reactive adduct and a second cellulose reactive adduct, wherein
said first cellulose reactive adduct comprises a reaction product of a starting polyvinylamine with at least a dialdehyde, wherein the starting polyvinylamine is a polymer formed from N-vinylformamide or N-vinylacetamide wherein said polymer is at least partially hydrolyzed to impart a degree of primary amino functionality, prior to the reaction with the dialdehyde, and
said second adduct comprises a reaction product of a dialdehyde with a starting polyvinylamide, with the proviso that the first and second cellulose reactive adducts are different.
2. A method for increasing the wet or dry strength of paper or board comprising the steps of:
a) providing an aqueous slurry of cellulosic fibers;
b) adding a blend of a first cellulose reactive adduct and a second cellulose reactive adduct to the aqueous cellulosic slurry, wherein
said first cellulose reactive adduct comprises a reaction product of a starting polyvinylamine polymer with at least a dialdehyde, wherein the starting polyvinylamine polymer is a polymer formed from N-vinylformamide or N-vinylacetamide wherein said polymer is at least partially hydrolyzed to impart a degree of primary amino functionality, prior to the reaction with the dialdehyde, and
said second cellulose reactive adduct comprises a reaction product of a dialdehyde with a starting polyvinylamide, with the proviso that the first and second cellulose reactive adducts are different;
c) forming a web from the aqueous slurry formed in step b); and
d) drying the web.
3. A method for increasing the wet or dry strength of paper or board comprising the steps of:
a) spraying, coating or otherwise applying onto a wet web, paper or board a blend comprising a first cellulose reactive adduct and a second cellulose reactive adduct, wherein
said first cellulose reactive adduct comprises a reaction product of a starting polyvinylamine polymer with at least a dialdehyde, wherein the starting polyvinylamine polymer is a polymer formed from N-vinylformamide or N-vinylacetamide wherein said polymer is at least partially hydrolyzed to impart a degree of primary amino functionality, prior to the reaction with the dialdehyde, and
said second cellulose reactive adduct comprises a reaction product of a dialdehyde with a starting polyvinylamide, with the proviso that the first and second cellulose reactive adducts are different; and
b) drying the coated wet web, paper or board.