Paper and paperboard products

Patent metadata

Field	Value
Publication number	US-10801162-B2
Application number	US-201816233458-A
Country	US
Kind code	B2
Filing date	Dec 27, 2018
Priority date	Apr 5, 2016
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

The present invention is directed to products, such as paper and paperboard products, comprising a substrate containing cellulose and top ply comprising microfibrillated cellulose and inorganic particulate, to methods of making such paper and paperboard products, and associated uses of such paper and paperboard products. The microfibrillated cellulose and inorganic particulate material are applied at the stage when the wet substrate is in the process of being formed on the wire of a papermaking machine, thereby avoiding the additional cost of more extensive equipment and machinery as well as in separate drying of a coating. The microfibrillated cellulose facilitates the application of inorganic particulate onto the surface of a wet paper or paperboard substrate when applied thusly, by trapping the inorganic particulate on the surface of the substrate and by giving the composite sufficient strength and a suitable pore structure to make it suitable for printing and other end-use demands.

First claim

The invention claimed is:

1. A paper or paperboard product comprising:
a cellulose-containing substrate; and
(ii) a top ply comprising an inorganic particulate material and at least 5 wt. % to 30 wt. % microfibrillated cellulose based on the total weight of the top ply, wherein the inorganic particulate material content is 67 wt. % to 92 wt. % based on the total weight of the top ply, wherein the inorganic particulate material has a particle size distribution in which at least 20 wt. % to at least 95 wt. % of the particles have an equivalent spherical diameter, e.s.d., of less than 2 μm, and further wherein the brightness measured, according to ISO Standard 11475(F8; D65—400 nm), on the top ply is at least about 65%; and wherein the top ply has a grammage of about 15 g/m 2 to about 40 g/m 2 .

2. The product according to claim 1 , wherein the product comprises a white top containerboard product.

3. The product according to claim 2 , wherein the substrate has a grammage suitable for use in a containerboard product, comprising a grammage ranging from 50 g/m 2 to 500 g/m 2 .

4. The product according to claim 1 , wherein the substrate comprises recycled pulp, dark kraft, or combinations thereof.

5. The product according to claim 1 , wherein the inorganic particulate material and the microfibrillated cellulose comprise greater than 95 wt. % of the top ply, based on the total weight of the top ply.

6. The product according to claim 1 , wherein the top ply comprises at least 70 wt. % of an inorganic particulate material, based on the total weight of the top ply.

7. The product according to claim 1 , wherein the top ply comprises at least 80 wt. % of an inorganic particulate material, based on the total weight of the top ply.

8. The product according to claim 1 , wherein the top ply comprises at least 10 wt. % to 20 wt. % microfibrillated cellulose, based on the total weight of the top ply.

9. The product according to claim 8 , wherein the top ply comprises at least one inorganic particulate material selected from the group consisting of: calcium carbonate, magnesium carbonate, dolomite, gypsum, an anhydrous kandite clay, kaolin, perlite, diatomaceous earth, wollastonite, talc, magnesium hydroxide, titanium dioxide, or aluminium trihydrate, or combinations thereof.

10. The product according to claim 9 , wherein the inorganic particulate material comprises calcium carbonate.

11. The product according to claim 1 , wherein the product has a PPS roughness, @1000 kPa measured on the top ply of no more than about 6.0 μ.m and/or a PPS roughness, @1000 kPa measured on the top ply which is at least 2.0 μ.m less than the PPS roughness of the substrate absent the top ply.

12. The product according to claim 1 , wherein the top ply comprises up to 2 wt. %, in total, of additives selected from the group consisting of: flocculant, formation/drainage aid, water soluble thickener, starch, retention aid and combinations thereof.

13. The product of claim 1 , wherein top ply is devoid of additional organic compound.

14. The product according to claim 13 , wherein the top ply is devoid of cationic polymer, anionic polymer, or polysaccharide hydrocolloid.

15. The product of claim 1 , wherein the top ply is devoid of wax, polyolefins, and silicone.

16. The product according to claim 1 , wherein the substrate comprises up to 1 wt. % retention aid, based on the total weight of the substrate.

17. The product according to claim 1 , wherein the top ply consists essentially of inorganic particulate and microfibrillated cellulose.

18. The product according to claim 1 , further comprising a further layer or ply, or further layers or plies, on the ply comprising at least about 5 wt. % to about 30 wt. % microfibrillated cellulose, based on the total weight of the top ply.

19. The product according to claim 18 , wherein at least one of the further layers or plies is a barrier layer or ply, or wax layer or ply, or silicon layer or ply.

Assignees

• Fiberlean Tech Ltd

Inventors

• Svending Per
• Phipps Jonathan Stuart
• Kritzinger Johannes
• Larson Tom
• Selina Tania
• Skuse David

Classifications

• D21H27/32 Primary

  with materials applied between the sheets (attaching together paper or cardboard sheets B31F5/00; adhesives C09J) · CPC title

• D21H21/10

  Retention agents or drainage improvers · CPC title

• D21H19/52

  Cellulose; Derivatives thereof · CPC title

• D21H17/68

  siliceous, e.g. clays · CPC title

• D21H17/675

  Oxides, hydroxides or carbonates · CPC title