# US 2017/0284030 A1 · Paper and paperboard products

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- Number: US 2017/0284030 A1
- Document ID: US20170284030A1
- Status: Published application
- Kind: A1
- Application number: 15/475,487
- Filed: 2017-03-31
- Published: 2017-10-05
- Earliest claimed: 2016-04-05
- Assignees: FiberLean Technologies Limited
- Applicants: FiberLean Technologies Limited
- Inventors: Per Svending; Jonathan Stuart Phipps; Johannes Kritzinger; Tom Larson; Tania Selina; David Skuse
- Web page: https://patentgrep.com/patent/US20170284030A1

## CPC

- D21H 27/32: with materials applied between the sheets (attaching together paper or cardboard sheets B31F5/00; adhesives C09J)
- D21H 11/04: Kraft or sulfate pulp
- D21H 11/14: Secondary fibres (working-up waste paper D21C5/02)
- D21H 11/18: Highly hydrated, swollen or fibrillatable fibres
- D21H 17/28: Starch
- D21H 17/67: Water-insoluble compounds, e.g. fillers, pigments
- D21H 17/675: {Oxides, hydroxides or carbonates}
- D21H 17/68: siliceous, e.g. clays
- D21H 19/52: Cellulose; Derivatives thereof
- D21H 21/10: Retention agents or drainage improvers
- D21H 21/52: Additives of definite length or shape
- D21H 27/10: Packing paper (packaging materials of special type or form B65D65/38)
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR

## 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.

## Claims

### Claim 1

A paper or paperboard product comprising:
(i) a cellulose-containing substrate; and
(ii) a top ply comprising an inorganic particulate material and at least about 5 wt. % microfibrillated cellulose based on the total weight of the top ply, wherein the inorganic particulate material content is about 67 wt. % to about 92 wt. % based on the total weight of the top ply, and further wherein the brightness measured (according to ISO Standard 11475 (F8; D65-400 nm)) on the top ply is at least about 65%.

### Claim 2 (depends on 1)

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

### Claim 3 (depends on 1)

The product a claim 1, wherein the product comprises or is a white top paperboard product.

### Claim 4 (depends on 2)

The product according to claim 2, wherein the substrate has a grammage suitable for use in a containerboard product, comprising a grammage ranging from about 50 g/m2 to about 500 g/m2, and/or the top ply has a grammage ranging from about 15 g/m2 to 40 g/m2.

### Claim 5 (depends on 4)

The product according to claim 4, wherein the top ply has a grammage of from about 15 to 40 g/m2.

### Claim 6 (depends on 1)

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

### Claim 7 (depends on 1)

The product according to claim 1, wherein the microfibrillated cellulose is present in the top ply in an amount of about 5 wt. % to about 30 wt. %.

### Claim 8 (depends on 1)

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.

### Claim 9 (depends on 1)

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.

### Claim 10 (depends on 1)

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

### Claim 11 (depends on 1)

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

### Claim 12 (depends on 1)

The product according to claim 1, 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.

### Claim 13 (depends on 12)

The product according to claim 12, wherein the inorganic particulate material comprises or is calcium carbonate.

### Claim 14 (depends on 1)

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 μm and/or a PPS roughness (@1000 kPa) measured on the top ply which is at least 2.0 μm less than the PPS roughness of the substrate absent the top ply.

### Claim 15 (depends on 1)

The product according to claim 1, wherein the top ply comprises up to about 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.

### Claim 16 (depends on 1)

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

### Claim 17 (depends on 16)

The product according to claim 16, wherein the top ply is devoid of cationic polymer, anionic polymer, or polysaccharide hydrocolloid.

### Claim 18 (depends on 1)

The product according to claim 1, wherein the top ply is an outer ply.

### Claim 19 (depends on 1)

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

### Claim 20

A paper or paperboard product comprising:
a cellulose-containing substrate; and a top ply comprising at least about 10 wt. % microfibrillated cellulose based on the total weight of the top ply, wherein the top ply is present in the product in an amount of about 15 g/m2 to 40 g/m2.

### Claim 21 (depends on 20)

The product according to claim 20, wherein the substrate comprises up to about 1 wt. % retention aid, based on the total weight of the substrate.

### Claim 22 (depends on 20)

The product according to claim 20, wherein the top ply consists essentially, or consists of, inorganic particulate and microfibrillated cellulose.

### Claim 23 (depends on 20)

The product according to claim 20, wherein the top ply comprises up to about 30 wt. % microfibrillated cellulose, based on the total weight of the top ply.

### Claim 24 (depends on 20)

The product according to claim 20, further comprising a further layer or ply, or further layers or plies, on the ply comprising at least about 30 wt. % microfibrillated cellulose, based on the total weight of the top ply.

### Claim 25 (depends on 24)

The product according to claim 24, 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.

### Claim 26

A method of making a paper or board product, the method comprising:
(a) providing a wet web of pulp;
(b) providing a top ply slurry onto the wet web of pulp, wherein:
(i) the top ply slurry is provided in an amount ranging from 15 g/m2 to 40 g/m2;
(ii) the top ply slurry comprises a sufficient amount of microfibrillated cellulose to obtain a product having a top ply comprising at least about 5 wt. % microfibrillated cellulose, based on the total weight of the top ply; and
(iii) the top ply slurry comprises a sufficient amount of inorganic particulate material to obtain a product having a top ply comprising at least 67 wt. % inorganic particulate material, based on the total weight of the top ply.

### Claim 27 (depends on 26)

The method according to claim 26, wherein the top ply slurry is applied using an applicator suitable to form a film through a non-pressurized or pressurized slot opening on top of a wet substrate on the wire of the wet end of a paper machine.

### Claim 28 (depends on 26)

The method according to claim 26, wherein the wet web of pulp comprises greater than about 50 wt. % of water, based on the total weight of the wet web of pulp.

### Claim 29 (depends on 26)

The method according to claim 26, wherein the wet web of pulp comprises up to about 1 wt. % of retention aid, based on the total weight of the wet web of pulp.

### Claim 30 (depends on 26)

The method according to claim 26, wherein the top ply slurry comprises inorganic particulate material and a sufficient amount of microfibrillated cellulose to obtain a paper product having a top ply comprising at least about 15 wt. % microfibrillated cellulose, based on the total weight of the top ply.

### Claim 31 (depends on 26)

The method according to claim 26, wherein the top ply slurry is applied using a pressurized slot opening on top of a wet substrate on the wire of the wet end of a paper machine.

### Claim 32 (depends on 26)

The method according to claim 26, wherein the top ply slurry is applied using a curtain coater.

### Claim 33 (depends on 26)

The method according to claim 26, further comprising applying a further layer or ply, or further layers or plies, onto the top ply comprising microfibrillated cellulose and inorganic particulate material.

### Claim 34 (depends on 33)

The method according to claim 33, 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.

### Claim 35 (depends on 20)

The product according to claim 20, wherein the top ply consists essentially, or consists of microfibrillated cellulose.