Process for preparing a lignin-based resin

Patent metadata

Field	Value
Publication number	US-12252593-B2
Application number	US-202117643970-A
Country	US
Kind code	B2
Filing date	Dec 13, 2021
Priority date	Apr 12, 2017
Publication date	Mar 18, 2025
Grant date	Mar 18, 2025

Abstract

The present invention relates to an improved process for preparing an aqueous dispersion of lignin and the use of said suspension in the preparation of a resin.

First claim

What is claimed is:

1. A method for preparing a resin comprising the steps of
a) providing an aqueous medium having a pH of 6;
b) adding lignin to the aqueous medium;
c) mixing until a dispersion of lignin in the aqueous medium has been obtained;
d) adding alkali, phenol and formaldehyde to the dispersion to form a mixture; and
e) maintaining the mixture at a temperature of from 30° C. to 95° C. for at least 30 minutes.

2. A method according to claim 1 , wherein steps a), b) and c) are carried out without actively heating the aqueous medium.

3. A method according to claim 1 , wherein the amount of lignin in the dispersion in step c) is 5-60 wt %.

4. A method according to claim 1 , wherein the amount of lignin in the dispersion in step c) is 35-60 wt %.

5. A method according to claim 1 , wherein the pH of the aqueous medium in step a) is pH 2 to 5.

6. A method according to claim 1 , wherein the pH of the aqueous medium in step a) is pH 2 to 6.

7. A method according to claim 1 , wherein the dispersion of lignin is stored or shipped to a different location before step d) is carried out.

8. A method according to claim 7 , wherein after the dispersion of lignin is stored or shipped to a different location, the dispersion of lignin is stirred before step d) is carried out.

9. A method according to claim 1 , wherein the aqueous medium further comprises up to 10 wt % of a solvent.

10. A method according to claim 9 , wherein the solvent comprises an alcohol.

11. A method according to claim 1 , wherein the aqueous medium further comprises up to 10 wt % of an additive.

12. A method according to claim 11 , wherein the additive comprises urea, a thickener, or a tenside.

13. A method according to claim 1 , wherein steps a), b), and c) are carried out at a temperature in a range of 15° C. to 40° C.

14. A method for preparing a resin comprising the steps of
a) providing an aqueous medium having a pH of 1 to 6;
b) adding lignin to the aqueous medium;
c) mixing until a dispersion of lignin in the aqueous medium has been obtained, wherein the amount of lignin in the dispersion in step c) is 5-60 wt %;
d) adding alkali, phenol and formaldehyde to the dispersion to form a mixture; and
e) maintaining the mixture at a temperature of from 30° C. to 95° C. for at least 30 minutes;
wherein steps a), b), and c) are carried out at a temperature in a range of 15° C. to 40° C.

15. A method according to claim 13 , wherein the amount of lignin in the dispersion in step c) is 35-60 wt %.

16. A method according to claim 13 , wherein the pH of the aqueous medium in step a) is pH 2 to 5.

17. A method according to claim 13 , wherein the pH of the aqueous medium in step a) is pH 5 to 6.

18. A method according to claim 13 , wherein the dispersion of lignin is stored or shipped to a different location before step d) is carried out.

19. A method according to claim 17 , wherein after the dispersion of lignin is stored or shipped to a different location, the dispersion of lignin is stirred before step d) is carried out.

20. A method according to claim 13 , wherein the aqueous medium further comprises up to 10 wt % of a solvent.

21. A method according to claim 13 , wherein the aqueous medium further comprises up to 10 wt % of an additive.

Assignees

• Stora Enso Oyj

Inventors

• Nasli Bakir Ben
• Areskogh Dimitri

Classifications

• C08L97/005

  Lignin · CPC title

• C08J2461/06

  of aldehydes with phenols · CPC title

• C08J2397/00

  Characterised by the use of lignin-containing materials · CPC title

• B27N3/002 Primary

  characterised by the type of binder (compositions of macromolecular compounds C08L) · CPC title

• C08H6/00

  Macromolecular compounds derived from lignin, e.g. tannins, humic acids · CPC title