Absorbent sheets prepared with cellulosic microfibers
View Patent ↗An absorbent paper sheet for tissue or towel includes an amount by weight of pulp-derived papermaking fibers, and an amount by weight of fibrillated regenerated cellulosic microfibers prepared from a cellulosic dope of dissolved cellulose comprising a solvent selected from tertiary amine N-oxides, cellulose dissolving imidazolium salts, cellulose dissolving pyridinium salts, cellulose dissolving pyridazinium salts, cellulose dissolving pyrimidinium salts, cellulose dissolving pyrazinium salts, cellulose dissolving pyrazolium salts, cellulose dissolving oxazolium salts, cellulose dissolving 1,2,3-triazolium salts, cellulose dissolving 1,2,4-triazolium salts, cellulose dissolving thiazolium salts, cellulose dissolving piperidinium salts, cellulose dissolving pyrrolidinium salts, cellulose dissolving quinolinium salts, and cellulose dissolving isoquinolinium salts.
1. An absorbent paper sheet for tissue or towel, the absorbent paper sheet comprising:
(a) an amount by weight of pulp-derived papermaking fibers; and
(b) from about 1 percent to about 30 percent by weight of fibrillated regenerated independent cellulosic microfibers prepared from a cellulosic dope of dissolved cellulose comprising a solvent selected from tertiary amine N-oxides, cellulose dissolving imidazolium salts, cellulose dissolving pyridinium salts, cellulose dissolving pyridazinium salts, cellulose dissolving pyrimidinium salts, cellulose dissolving pyrazinium salts, cellulose dissolving pyrazolium salts, cellulose dissolving oxazolium salts, cellulose dissolving 1,2,3-triazolium salts, cellulose dissolving 1,2,4-triazolium salts, cellulose dissolving thiazolium salts, cellulose dissolving piperidinium salts, cellulose dissolving pyrrolidinium salts, cellulose dissolving quinolinium salts, and cellulose dissolving isoquinolinium salts.
2. The absorbent paper sheet according to claim 1 , wherein the amount by weight of pulp-derived paper making fibers is from about 70 percent to about 99 percent by weight.
3. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 100 ml.
4. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a weight average diameter of less than 1 micron, a weight average length of less than 400 microns, and a fiber count of greater than 2 billion fibers/gram.
5. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a weight average diameter of less than 0.5 microns, a weight average length of less than 300 microns, and a fiber count of greater than 10 billion fibers/gram.
6. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a weight average diameter of less than 0.25 microns, a weight average length of less than 200 microns, and a fiber count of greater than 50 billion fibers/gram.
7. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 100 ml.
8. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 50 ml.
9. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 25 ml.
10. The absorbent paper sheet according to claim 1 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of 0 ml.
11. An absorbent cellulosic sheet comprising:
(a) cellulosic pulp-derived papermaking fibers in an amount of from about 70 percent up to about 98 percent by weight; and
(b) from about 2 percent to about 30 percent by weight of fibrillated regenerated independent cellulosic microfibers prepared from a cellulosic dope of dissolved cellulose comprising a solvent selected from tertiary amine N-oxides, cellulose dissolving imidazolium salts, cellulose dissolving pyridinium salts, cellulose dissolving pyridazinium salts, cellulose dissolving pyrimidinium salts, cellulose dissolving pyrazinium salts, cellulose dissolving pyrazolium salts, cellulose dissolving oxazolium salts, cellulose dissolving 1,2,3-triazolium salts, cellulose dissolving 1,2,4-triazolium salts, cellulose dissolving thiazolium salts, cellulose dissolving piperidinium salts, cellulose dissolving pyrrolidinium salts, cellulose dissolving quinolinium salts, and cellulose dissolving isoquinolinium salts.
12. The absorbent cellulosic sheet according to claim 11 , wherein the fibrillated regenerated independent cellulosic microfibers have a number average fiber width of less than about 4 micrometers.
13. The absorbent cellulosic sheet according to claim 11 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 250 micrometers.
14. The absorbent cellulosic sheet according to claim 11 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 150 micrometers.
15. The absorbent cellulosic sheet according to claim 11 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 100 micrometers.
16. The absorbent cellulosic sheet according to claim 11 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 75 micrometers.
17. The absorbent cellulosic sheet according to claim 11 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 100 ml.
18. The absorbent cellulosic sheet according to claim 11 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) of less than 50 ml.
19. The absorbent cellulosic sheet according to claim 11 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) of less than 25 ml.
20. The absorbent cellulosic sheet according to claim 11 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of 0 ml.
21. An absorbent cellulosic sheet comprising:
(a) an amount by weight of cellulosic pulp-derived papermaking fibers; and
(b) fibrillated regenerated independent cellulosic microfibers in an amount of from about 2 percent to about 30 percent by weight, wherein the fibrillated regenerated independent cellulosic microfibers are prepared from a cellulosic dope of dissolved cellulose comprising a solvent selected from tertiary amine N-oxides, cellulose dissolving imidazolium salts, cellulose dissolving pyridinium salts, cellulose dissolving pyridazinium salts, cellulose dissolving pyrimidinium salts, cellulose dissolving pyrazinium salts, cellulose dissolving pyrazolium salts, cellulose dissolving oxazolium salts, cellulose dissolving 1,2,3-triazolium salts, cellulose dissolving 1,2,4-triazolium salts, cellulose dissolving thiazolium salts, cellulose dissolving piperidinium salts, cellulose dissolving pyrrolidinium salts, cellulose dissolving quinolinium salts, and cellulose dissolving isoquinolinium salts.
22. The absorbent cellulosic sheet according to claim 21 , wherein the fibrillated regenerated independent cellulosic microfibers have a number average fiber length of less than about 250 micrometers.
23. The absorbent cellulosic sheet according to claim 21 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 150 micrometers.
24. The absorbent cellulosic sheet according to claim 21 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 100 micrometers.
25. The absorbent cellulosic sheet according to claim 21 , wherein the number average fiber length of the fibrillated regenerated independent cellulosic microfibers is less than about 75 micrometers.
26. The absorbent cellulosic sheet according to claim 21 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 100 ml.
27. The absorbent cellulosic sheet according to claim 21 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 50 ml.
28. The absorbent cellulosic sheet according to claim 21 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of less than 25 ml.
29. The absorbent cellulosic sheet according to claim 21 , wherein the fibrillated regenerated independent cellulosic microfibers have a Canadian Standard Freeness (CSF) value of 0 ml.