Process for preparing self-binding pigment particle suspensions

Patent metadata

Field	Value
Publication number	US-9670366-B2
Application number	US-201214238508-A
Country	US
Kind code	B2
Filing date	Aug 22, 2012
Priority date	Aug 31, 2011
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

The invention relates to a process for preparing self-binding pigment particle suspensions, to a self-binding pigment particle suspension as well as to a paper product comprising self-binding pigment particles and to the use of the self-binding pigment particle suspension as filler material.

First claim

The invention claimed is:

1. A process for preparing a suspension of self-binding pigment particles, the process comprising the following steps:
a) providing an aqueous pigment material suspension, wherein the pigment of the pigment material suspension comprises calcium carbonate;
b) providing a polymeric binder, wherein the binder consists of at least one polysaccharide comprising galactose and/or mannose units;
c) mixing 0.1 wt.-% to 10 wt.-% of the binder of step b), based on the total weight of the aqueous pigment material suspension, with the aqueous pigment material suspension of step a), to obtain a mixture of the binder and the aqueous pigment material suspension; and
d) grinding the mixture of the binder and the aqueous pigment material suspension obtained in step c) to obtain a suspension of self-binding pigment particles, wherein the weight median diameter (d 50 ) of the self-binding pigment particles is less than the weight median diameter (d 50 ) of the pigment from step a).

2. The process according to claim 1 , wherein the pigment material of the pigment material suspension of step a) comprises calcium carbonate and one or more of dolomite, magnesium, clay, talc, kaolin, aluminium hydroxide, mica, titanium dioxide, synthetic fibers or natural fibers.

3. The process according to claim 1 , wherein the pigment material of the pigment material suspension of step a) is a ground natural calcium carbonate, a precipitated calcium carbonate, a modified calcium carbonate, or any mixture thereof.

4. The process according to claim 1 , wherein the pigment material of the pigment material suspension of step a) is a ground natural calcium carbonate.

5. The process according to claim 1 , wherein the binder of step b) is at least one polysaccharide comprising galactose and mannose units.

6. The process according to claim 1 , wherein the binder of step b) is at least one polysaccharide comprising a linear chain of 1,4-linked β-D-mannopyranosyl units or a linear chain of 1,4-linked β-D-mannopyranosyl units with 1,6-linked α-D-galactopyranosyl units.

7. The process according to claim 1 , wherein the binder of step b) is at least one polysaccharide having a ratio of mannose units to galactose units from 6:1 to 1:1.

8. The process according to claim 1 , wherein the binder of step b) is at least one polysaccharide having a ratio of mannose units to galactose units from 5:1 to 1:1.

9. The process according to claim 1 , wherein the binder of step b) is at least one polysaccharide having a ratio of mannose units to galactose units from 4:1 to 1:1.

10. The process according to claim 1 , wherein the binder of step b) is at least one polysaccharide having a ratio of mannose units to galactose units from 3:1 to 1:1.

11. The process according to claim 1 , wherein the binder of step b) is in a form of a hydrocolloidal solution or a dry material.

12. The process according to claim 1 , wherein the binder of step b) is in a form of a hydrocolloidal solution having a binder concentration from 0.05 wt.-% to 10 wt.-%, based on the total weight of the solution.

13. The process according to claim 1 , wherein the binder of step b) is in a form of a hydrocolloidal solution having a binder concentration from 0.1 wt.-% to 5 wt.-%, based on the total weight of the solution.

14. The process according to claim 1 , wherein the binder of step b) is in a form of a hydrocolloidal solution having a binder concentration from 0.1 wt.-% to 2 wt.-%, based on the total weight of the solution.

15. The process according to claim 1 , wherein the binder of step b) is in a form of a hydrocolloidal solution having a binder concentration from 0.1 wt.-% to 1 wt.-%, based on the total weight of the solution.

16. The process according to claim 1 , wherein in step c) 0.05 wt.-% to 5.0 wt.-% of the binder of step b), based on the total weight of the aqueous pigment material suspension, is mixed with the aqueous pigment material suspension of step a).

17. The process according to claim 1 , wherein in step c) 0.1 wt.-% to 2 wt.-% of the binder of step b), based on the total weight of the aqueous pigment material suspension, is mixed with the aqueous pigment material suspension of step a).

18. The process according to claim 1 , wherein in step c) 0.1 wt.-% to 2 wt.-% of the binder of step b), based on the total weight of the aqueous pigment material suspension, is mixed with the aqueous pigment material suspension of step a).

19. The process according to claim 1 , wherein in step c) 0.25 wt.-% to 1 wt.-% of the binder of step b), based on the total weight of the aqueous pigment material suspension, is mixed with the aqueous pigment material suspension of step a).

20. The process according to claim 1 , wherein in step c), the pigment material suspension has a solids content of 5 wt.-% to 80 wt.-%, based on the total weight of the pigment material suspension.

21. The process according to claim 1 , wherein in step c), the pigment material suspension has a solids content of 10 wt.-% to 60 wt.-%, based on the total weight of the pigment material suspension.

22. The process according to claim 1 , wherein in step c), the pigment material suspension has a solids content of 15 wt.-% to 45 wt.-%, based on the total weight of the pigment material suspension.

23. The process according to claim 1 , wherein grinding step d) is carried out at a temperature from 10° C. to 110° C.

24. The process according to claim 1 , wherein grinding step d) is carried out at a temperature from 20° C. to 60° C.

25. The process according to claim 1 , wherein grinding step d) is carried out at a temperature from 20° C. to 45° C.

26. The process according to claim 1 , wherein grinding step d) is carried out until the fraction of self-binding pigment particles having a particle size of less than 1 μm is greater than 20 wt.-%, based on the total weight of the pigment particles.

27. The process according to claim 1 , wherein grinding step d) is carried out until the fraction of self-binding pigment particles having a particle size of less than 1 μm is greater than 40 wt.-%, based on the total weight of the pigment particles.

28. The process according to claim 1 , wherein grinding step d) is carried out until the fraction of self-binding pigment particles having a particle size of less than 1 μm is greater than 50 wt.-%, based on the total weight of the pigment particles.

29. The process according to claim 1 , wherein grinding step d) is carried out until the fraction of self-binding pigment particles having a particle size of less than 1 μm is greater than 60 wt.-%, based on the total weight of the pigment particles.

30. The process according to claim 1 , wherein grinding step d) is carried out in batch or continuously.

31. The process according to claim 1 , wherein the suspension of self-binding pigment particles obtained in step d) is concentrated such that the solids content in the suspension is at least 45 wt.-%, based on the total weight of the pigment material suspension.

32. The process according to claim 1 , wherein the suspension of self-binding pigment particles obtained in step d) is concentrated such that the solids content in the suspension is from 45 wt.-% to 80 wt.-%, based on the total weight of the pigment material suspension.

33. The process ac

Assignees

• Gantenbein Daniel
• Schoelkopf Joachim
• Gane Patrick A C
• Omya Int Ag

Inventors

• Gantenbein Daniel
• Schoelkopf Joachim
• Gane Patrick A C

Classifications

• C01P2006/22

  Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability · CPC title

• C01P2006/60

  Optical properties, e.g. expressed in CIELAB-values · CPC title

• D21H17/74 Primary

  of organic and inorganic material · CPC title

• D21H17/675

  Oxides, hydroxides or carbonates · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title