Modified vinylamine/vinylformamide polymers for use as creping adhesives

1. A method of creping a paper web comprising:

a) preparing an adhesive composition having a pH of about 7 to about 7.5 and comprising one or more vinylamine/N-vinyl formamide polymers composed of about 10 to about 99 mole percent vinylamine monomer and about 90 to about 1 mole percent N-vinyl formamide monomer;

b) modifying the vinylamine/N-vinyl formamide polymers by reaction with a halogenated organic acid;

c) after modifying the vinylamine/N-vinyl formamide polymers, applying the adhesive composition to a rotating creping cylinder d) pressing the paper web against the creping cylinder to effect adhesion of the paper web to the creping cylinder; and

e) dislodging the paper web from the creping cylinder with a doctor blade;

wherein the vinylamine/N-vinyl formamide polymers are reacted with a crosslinker before it is modified with the organic acid, and wherein the halogenated acid is chloroacetic acid in an amount of between about 10 weight percent to about 15 weight percent based on polymer actives.

2. The method of claim 1 wherein the polymers have a weight average molecular weight of about 100,000 to about 500,000 Daltons.

3. The method of claim 2 wherein the polymers are composed of about 20 to about 80 mole percent vinylamine monomer and about 80 to about 20 mole percent N-vinylformamide monomer.

4. The method of claim 3 wherein the polymer composition has a pH of about 7 to about 7.5.

5. The method of claim 4 wherein the polymers have a weight average molecular weight of about 300,000 to about 400,000 Daltons.

6. The method of claim 1 wherein the vinylamine/N-vinyl formamide polymers are reacted with about 1 to about 10 percent, based on polymer actives, of one or more crosslinkers wherein the crosslinkers contain at least one epoxide group and no halogens.

7. The method of claim 6 wherein the vinylamine/N-vinyl formamide polymers are composed of about 30 to about 99 mole percent vinylamine monomer and about 70 to about 1 mole percent N-vinylformamide monomer.

8. The method of claim 7 wherein the vinylamine/N-vinyl formamide polymers have a weight average molecular weight of about 10,000 to about 100,000 Daltons papermaking additive.

9. The method of claim 8 wherein the crosslinkers are selected from polyethyleneglycol diglycidyl ether and trimethylolpropane triglycidyl ether.

10. The method of claim 9 wherein the vinylamine/N-vinyl formamide polymers are composed of about 85 to about 95 mole percent vinylamine monomer and about 15 to about 5 mole percent N-vinylformamide monomer.

11. The method of claim 10 wherein the vinylamine/N-vinyl formamide polymers have a weight average molecular weight of about 30,000 to about 60,000 Daltons.

12. The method of claim 1 wherein the adhesive composition further comprises one or more water-soluble polyols.

13. The method of claim 12 wherein the water-soluble polyols are selected from glycerol, ethylene glycol, sorbitol, diethylene glycol, propylene glycol, polyethylene glycol and diethanolamine.

14. The method of claim 12 wherein the water-soluble polyol is glycerol.

15. The method of claim 1 wherein the vinylamine/N-vinyl formamide polymers are also reacted with about 1 to about 10 percent, based on polymer actives, of one or more additional crosslinkers wherein the additional crosslinkers contain at least one epoxide group one or more polymers selected from the group consisting of polyaminoamides, polyalkylenepolyamines, poly(vinyl alcohol/vinylacetate), polyethylenimines and polyvinylamine copolymers in a ratio of about 5/95 to about 95/5 by weight applied to said creping cylinder by a spray boom located proximate to said creping cylinder.

16. The method of claim 1 wherein the polymer modification by reaction with acid is accomplished by heating the polymer in the presence of acid at 80 degrees C. for 2 hours.

17. The method of claim 1 wherein the crosslinker is trimethylolpropane triglycidyl ether.