Glue-bonded multi-ply absorbent sheet and polyvinyl alcohol ply bonding adhesive

Patent metadata

Field	Value
Publication number	US-10954417-B2
Application number	US-201815951630-A
Country	US
Kind code	B2
Filing date	Apr 12, 2018
Priority date	Jan 28, 2015
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A multi-ply absorbent sheet includes a first absorbent ply of cellulosic sheet; a second absorbent ply of cellulosic sheet; and a ply bonding adhesive interposed between the first absorbent ply and the second absorbent ply, the ply-bonding adhesive thereby adhering said absorbent plies together. The ply-bonding adhesive comprises polyvinyl alcohol and nanofibrillated cellulose. In a particularly preferred embodiment the adhesive is applied as a dilute aqueous composition to tissue plies and the nanofibrillated cellulose has a Characteristic Breaking Length of 6.5 km or above.

First claim

What is claimed is:

1. A method of making absorbent sheet comprising:
(a) providing a first absorbent cellulosic basesheet;
(b) providing a second absorbent cellulosic basesheet;
(c) interposing an aqueous adhesive containing polyvinyl alcohol and nanofibrillated cellulose between said first and second cellulosic basesheets; and
(d) plying said first absorbent cellulosic basesheet with said second absorbent cellulosic basesheet by pressing said absorbent cellulosic basesheets together.

2. The method of making a multi-ply absorbent sheet according to claim 1 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 200,000 cP at a shear rate of 1 sec −1 and a Characteristic Nanofiber Viscosity of less than 50,000 cP at a shear rate of 50 sec −1 .

3. The method of making a multi-ply absorbent sheet according to claim 1 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 350 cP at a shear rate of 1 sec −1 and a Characteristic Nanofiber Viscosity of less than 50 cP at a shear rate of 50 sec −1 .

4. The method of making a multi-ply absorbent sheet according to claim 1 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 4,000 cP at a shear rate of 1 sec −1 and a Characteristic Viscosity of less than 1,500 cP at a shear rate of 50 sec −1 .

5. The method of making a multi-ply absorbent sheet according to claim 1 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 15,000 cP at a shear rate of 5 sec −1 and a Characteristic Nanofiber Viscosity of less than 2,000 cP at a shear rate of 500 sec −1 .

6. The method of making a multi-ply absorbent sheet according to claim 1 , wherein the adhesive contains from 0.5% by weight to 20% by weight of nanofibrillated cellulose, based on the weight of polyvinyl alcohol.

7. The method of making a multi-ply absorbent sheet according to claim 1 , wherein the adhesive contains from 0.5% by weight to 30% by weight of nanofibrillated cellulose, based on the weight of polyvinyl alcohol.

8. The method of making a multi-ply absorbent sheet according to claim 1 , wherein the adhesive contains from 0.5% by weight to 40% by weight of nanofibrillated cellulose, based on the weight of polyvinyl alcohol.

9. The method of making a multi-ply absorbent sheet according to claim 1 , wherein the adhesive contains from 0.5% by weight to 50% by weight of nanofibrillated cellulose, based on the weight of polyvinyl alcohol.

10. The method of making a multi-ply absorbent sheet according to claim 1 , wherein the adhesive contains from 1% by weight to 10% by weight of nanofibrillated cellulose, based on the weight of polyvinyl alcohol.

11. A ply bonding adhesive for the manufacture of multi-ply paper tissue and multi-ply paper towel comprising:
(a) water in an amount of from 90-98.5% by weight of the adhesive composition;
(b) polyvinyl alcohol in an amount of from 1.5% to 10% by weight based on the weight of the adhesive composition; and
(c) from 1% to 50% by weight of nanofibrillated cellulose based on the weight of polyvinyl alcohol in the adhesive composition.

12. The ply bonding adhesive according to claim 11 , wherein the adhesive comprises from to 1.5% to 6% by weight of the composition polyvinyl alcohol and from 1% to 20% by weight of nanofibrillated cellulose based on the weight of polyvinyl alcohol in the adhesive.

13. The ply bonding adhesive according to claim 11 , wherein the adhesive comprises from to 1.5% to 6% by weight of the composition polyvinyl alcohol and from 1% to 40% by weight of nanofibrillated cellulose based on the weight of polyvinyl alcohol in the adhesive.

14. The ply bonding adhesive according to claim 11 , wherein the adhesive comprises from to 1.5% to 6% by weight of the composition polyvinyl alcohol and from 1% to 50% by weight of nanofibrillated cellulose based on the weight of polyvinyl alcohol in the adhesive.

15. The ply bonding adhesive according to claim 11 , wherein the adhesive is applied between plies of a multi-ply absorbent sheet as an aqueous composition containing from 1.5% to 3% by weight of the composition polyvinyl alcohol.

16. The ply bonding adhesive according to claim 11 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 200,000 cP at a shear rate of 1 sec −1 and a Characteristic Nanofiber Viscosity of less than 50,000 cP at a shear rate of 50 sec −1 .

17. The ply bonding adhesive according to claim 11 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 350 cP at a shear rate of 1 sec −1 and a Characteristic Nanofiber Viscosity of less than 50 cP at a shear rate of 50 sec −1 .

18. The ply bonding adhesive according to claim 11 , wherein said nanofibrillated cellulose has a Characteristic Nanofiber Viscosity of greater than 4,000 cP at a shear rate of 1 sec −1 and a Characteristic Nanofiber Viscosity of less than 1,500 cP at a shear rate of 50 sec −1 .

19. The ply bonding adhesive according to claim 11 , wherein said nanofibrillated cellulose has a Characteristic Breaking Length of from 4.5 km to 9 km.

20. The ply bonding adhesive according to claim 11 , wherein the polyvinyl alcohol in the adhesive has a Characteristic PVOH Viscosity of from 3 to 75 cP.

Assignees

• Gpcp Ip Holdings Llc

Inventors

• Sumnicht Daniel W
• Yu Zhiying
• Vaijapurkar Siddharth S

Classifications

• C08L1/02

  Cellulose; Modified cellulose · CPC title

• C08L29/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C09J129/04 Primary

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C09J101/02

  Cellulose; Modified cellulose · CPC title

• C08L2205/16

  Fibres; Fibrils · CPC title