Crosslinked cellulose as precursor in production of high-grade cellulose derivatives and related technology

Patent metadata

Field	Value
Publication number	US-9771687-B2
Application number	US-201615067749-A
Country	US
Kind code	B2
Filing date	Mar 11, 2016
Priority date	Feb 25, 2016
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A pulp in accordance with a particular embodiment includes crosslinked cellulose fibers. The pulp can have high brightness, reactivity, and intrinsic viscosity. The pulp, therefore, can be well suited for use as a precursor in the production of low-color, high-viscosity cellulose derivatives. A method in accordance with a particular embodiment of the present technology includes forming a pulp from a cellulosic feedstock, bleaching the pulp, crosslinking cellulose fibers within the pulp while the pulp has a high consistency, and drying the pulp. The bleaching process can reduce a lignin content of the pulp to less than or equal to 0.09% by oven-dried weight of the crosslinked cellulose fibers. Crosslinking the cellulose fibers can include exposing the cellulose fibers to a glycidyl ether crosslinker having two or more glycidyl groups and a molecular weight per epoxide within a range from 140 to 175.

First claim

What is claimed is:

1. Pulp, comprising:
crosslinked cellulose fibers,
wherein the pulp has
a resultant carboxymethyl cellulose viscosity greater than or equal to 60 centipoise,
a brightness greater than or equal to 75%, and
a water retention value greater than or equal to 1.1 g/g.

2. The pulp of claim 1 , wherein the pulp is a Kraft pulp.

3. The pulp of claim 1 , wherein the pulp is bleached.

4. The pulp of claim 1 , wherein the pulp is at least partially insoluble in cupriethylenediamine.

5. The pulp of claim 1 , further comprising less than or equal to 0.09% lignin by oven-dried weight of the crosslinked cellulose fibers.

6. The pulp of claim 1 , further comprising greater than or equal to 10% hemicellulose by oven-dried weight of the crosslinked cellulose fibers.

7. The pulp of claim 1 , wherein the pulp has a resultant carboxymethyl cellulose viscosity greater than or equal to 90 centipoise.

8. The pulp of claim 1 , wherein the pulp has a resultant carboxymethyl cellulose color less than or equal to 5.

9. The pulp of claim 1 , wherein the pulp has a resultant carboxymethyl cellulose turbidity less than or equal to 25 ntu.

10. The pulp of claim 1 , wherein the pulp has a water retention value less than or equal to 1.4 g/g.

11. The pulp of claim 1 , wherein the pulp has a R18 value greater than or equal to 88.

12. The pulp of claim 11 , wherein the pulp has a R18 value less than or equal to 92.

13. The pulp of claim 1 , wherein the pulp has a falling ball viscosity greater than or equal to 200 centipoise.

14. The pulp of claim 1 , wherein the pulp has no cellulose-II as determined by x-ray crystallography.

15. The pulp of claim 1 , wherein the pulp has a crystallinity index less than or equal to 75%.

16. The pulp of claim 15 , wherein the pulp has a crystallinity index less than or equal to 80%.

17. The pulp of claim 1 , wherein the pulp has a brightness greater than or equal to 80%.

18. The pulp of claim 17 , wherein the pulp has a brightness less than or equal to 88.5%.

19. The pulp of claim 1 , wherein the pulp has a basis weight of greater than or equal to 500 g/m 2 .

20. The pulp of claim 19 , wherein the pulp has a basis weight less than or equal to 1200 g/m 2 .

21. The pulp of claim 1 , wherein the pulp has a density greater than or equal to 0.20 g/cm 3 .

22. The pulp of claim 1 , wherein the pulp has a freeness greater than or equal to 700 ml.

23. The pulp of claim 1 , wherein the crosslinked cellulose fibers include crosslinks derived from a glycidyl ether crosslinker having two or more glycidyl groups.

24. The pulp of claim 1 , wherein the crosslinked cellulose fibers include crosslinks derived from a glycidyl ether crosslinker having a weight average molecular weight within a range from 174 to 500.

25. The pulp of claim 1 , wherein the crosslinked cellulose fibers include crosslinks derived from a glycidyl ether crosslinker having a weight per epoxide within a range from 140 to 175.

26. The pulp of claim 1 , wherein the crosslinked cellulose fibers include crosslinks derived from a glycidyl ether crosslinker having a first glycidyl group, a second glycidyl group, and either three or four linear chain carbon atoms between the first and second glycidyl groups.

27. The pulp of claim 1 , wherein the crosslinked cellulose fibers are derived from wood.

Assignees

• Int Paper Co

Inventors

• Lou Mengkui

Classifications

• C08B15/10 Primary

  Crosslinking of cellulose · CPC title

• D21H11/14

  Secondary fibres (working-up waste paper D21C5/02) · CPC title

• D21H13/04 Primary

  Cellulose ethers · CPC title

• D21C9/147

  with oxygen or its allotropic modifications (D21C9/16 takes precedence) · CPC title

• C08L97/02

  Lignocellulosic material, e.g. wood, straw or bagasse {(manufacture of articles made from lignocellulosic material by dry processes B27N)} · CPC title