Amino-functionalized pulp fibers
View Patent ↗The disclosed invention is directed to pulp fibers suitable for forming a wet-laid paper product which include amino-functionality which is non-extractable in an aqueous phase. The pulp fibers may be prepared by applying an amino-functional additive to a fibrous web prior to the finishing operation at a pulp mill. The fibrous web may then be repulped at a papermaking machine to form a paper web which includes the amino-functionalized fibers of the present invention. A paper web formed of the amino-functionalized fibers may display unique and/or improved reactivity toward certain papermaking additives. For instance, the paper webs of the disclosed invention may show dry tensile strength increases of greater than 40% when treated with a permanent wet strength agent such as a polyamine epichlorohydrin wet strength agent, whereas a paper web which does not include the amino-functionalized fibers of the present invention may show less than a 20% increase in strength properties when treated with the same strength agents.
1. A papermaking fiber comprising a cellulosic fiber and an amino-functional additive adhered to the fiber, wherein the amino-functional additive has a primary amine content greater than about 0.90 m-eq primary amine per gram amino-functional additive, the amino-functional additive having a retention level on the cellulosic fiber of at least about 50% under aqueous conditions, wherein the amino-functional additive is a substantially water-insoluble polymeric amino-functional additive.
2. The papermaking fiber of claim 1 , wherein the amino-functional additive has a primary amine content greater than about 0.94 m-eq primary amine per gram amino-functional additive.
3. The papermaking fiber of claim 1 , wherein the papermaking fiber has a Canadian Standard Freeness value greater than about 200.
4. The papermaking fiber of claim 1 , wherein the papermaking fiber has a Canadian Standard Freeness value greater than about 500.
5. The papermaking fiber of claim 1 , wherein the substantially water-insoluble polymeric amino-functional additive has a solubility of less than about 3 g/100 cc deionized water.
6. The papermaking fiber of claim 1 , wherein the amino-functional additive is a polyvinylamine.
7. The papermaking fiber of claim 1 , wherein the amino-functional additive is a polyoxyalkylpolyamine.
8. The papermaking fiber of claim 1 , wherein the cellulosic fiber and the amino-functional additive are not covalently bon ed together.
9. The papermaking fiber of claim 1 , wherein the amino-functional additive has a retention level on the cellulosic fiber of at least about 60% under aqueous conditions.
10. The papermaking fiber of claim 1 , wherein the amino-functional additive has a retention level on the cellulosic fiber of at least about 75% under aqueous conditions.
11. The papermaking fiber of claim 1 , wherein the papermaking fiber comprises the amino-functional additive in an amount of from about 0.05% to about 5% by weight of the cellulosic fiber.
12. The papermaking fiber of claim 1 , wherein the papermaking fiber comprises the amino-functional additive in an amount of from about 0.1% to about 2.5% by weight of the cellulosic fiber.
13. The papermaking fiber of claim 1 , wherein the cellulosic fiber is a high yield pulp fiber.
14. The papermaking fiber of claim 1 , wherein the cellulosic fiber is a virgin fiber.
15. A paper web comprising:
a plurality of amino-functionalized papermaking fibers comprising a cellulosic fiber adhered to an amino-functional additive, wherein the amino-functional additive has a primary amine content greater than about 0.90 m-eq primary amine per gram, the amino-functional additive having a retention level on the cellulosic fiber of at least about 50% under aqueous conditions, wherein the amino-functional additive is a substantially water-insoluble polymeric amino-functional additive, the amino-functionalized papermaking fibers having no significant fiber degredation; and
a papermaking additive capable of reacting with the amino-functionalized papermaking fibers.
16. A paper web as defined in claim 15 , wherein th paper web comprises from about 0.05% to about 5% amino-functional additive by eight of the amino-functionalized papermaking fibers.
17. A paper web as defined in claim 15 , wherein the paper web comprises from about 0.1% to about 2.5% amino-functional additive by weight of the amino-functionalized papermaking fibers.
18. A paper web as defined in claim 15 , wherein the papermaking additive is a wet strength agent.
19. A paper web as defined in claim 18 , wherein the dry tensile index of the web is at least about 40% greater than the dry tensile index of a comparable paper web which does not comprise the wet strength agent.
20. A paper web as defined in claim 18 , wherein the wet strength agent is a temporary wet strength agent.
21. A paper web as defined in claim 18 , wherein the wet strength agent is a permanent wet strength agent.
22. A paper web as defined in claim 15 , wherein the papermaking additive is a polymeric anionic reactive compound.
23. A paper web as defined in claim 15 , wherein the papermaking additive is a polymeric aldehyde functional compound.
24. A paper web as defined in claim 15 , wherein the paper web is a stratified paper web.
25. A paper web as defined in claim 15 , comprising between about 0.1% and about 10% papermaking additive by weight of the paper web.
26. A paper web as defined in claim 15 , wherein the paper web comprises between about 10% and about 100% amino-functionalized papermaking fibers by weight of the paper web.
27. A paper web as defined in claim 15 , wherein the paper web comprises about 50% amino-functionalized papermaking fibers by weight of the paper web.
28. A paper web as defined in claim 15 , wherein the amino-functional additive has a primary amine content greater than about 0.9 m-eq primary amine per gram.
29. A paper web as defined in claim 15 , wherein the amino-functionalized papermaking fibers have a Canadian Standard Freeness value greater than about 200.
30. A paper web as defined in claim 15 , wherein the substantially water-insoluble polymeric amino-functional additive has a solubility of less than about 3 g/100 cc deionized water.
31. A paper web as defined in claim 15 , wherein the amino-functional additive is a polyvinylamine.
32. A paper web as defined in claim 15 , wherein the amino-functional additive is a polyoxyalkylpolyamine.
33. A paper web as defined in claim 15 , wherein the amino-functional additive has a retention level on the cellulosic fiber of at leas about 60% under aqueous conditions.
34. A paper web as defined in claim 15 , wherein the amino-functional additive has a retention level on the cellulosic fiber of at least about 75% under aqueous conditions.
35. A paper web as defined in claim 15 , wherein the paper web is an uncreped, through-dried paper web.
36. A paper web as defined in claim 15 , wherein the paper web is a creped web.
37. A method for forming amino-functionalized pulp fiber comprising:
creating a fiber slurry comprising process water and papermaking fibers;
forming a wet fibrous web comprising said papermaking fibers;
dewatering the wet fibrous web to a consistency of about 30% or greater;
applying an amino-functional additive to the dewatered fibrous web, wherein the amino-functional additive adheres to the papermaking fibers thereby forming a dewatered fibrous web comprising amino-functionalized papermaking fibers; and
repulping the dried fibrous web comprising the amino-functionalized papermaking fibers so as to form a slurry of the amino-functionalized papermaking fibers, wherein the amino-functionalized papermaking fibers retain at least about 50% of the amino-functional additive applied to the fibers upon repulping the fibers.
38. The method of claim 37 further comprising curing the amino-functionalized papermaking fibers.
39. The method of claim 37 , wherein the amino-functional additive is applied to the paper web in an amount of from about 0.05% to about 5% by weight of the papermaking fibers.
40. The method of claim 37 , wherein the amino-functional additive is applied to the paper web in an amount of from about 0.1% to about 2 5% by weight of the papermaking fibers.
41. The method of claim 37 , further comprising forming a paper web from said slurry of amino-functionalized papermaking fibers.
42. The method of claim 41 , wherein said paper web comprises from about 10% to about 100% amino-functionalized papermaking fibers by weight.
43. The method of claim 41 , further comprising applying a papermaking additive to said paper web, wherein the papermaking additive is capable of reacting with the amino-functionalized papermaking fibers.
44. The method of claim 43 , wherein the papermaking additive is a wet strength agent.
45. The method of claim 43 , wherein the wet strength the agent is a temporary wet strength agent.
46. The method of claim 43 , wherein the wet strength the agent is a permanent wet strength agent.
47. The method of claim 43 , wherein the papermaking additive is applied to the paper web in an amount of between about 0.1% and about 10% by weight of the paper web.