# US 8,771,469 B2 · Reactive cationic resins for use as dry and wet strength agents in sulfite ion-containing papermaking systems

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- Number: US 8,771,469 B2
- Document ID: US8771469B2
- Status: Granted
- Kind: B2
- Application number: 12/941,620
- Filed: 2010-11-08
- Published: 2011-03-10
- Granted: 2014-07-08
- Earliest claimed: 2004-12-21
- Assignees: Hercules Incorporated
- Applicants: Shane Cyr; Henk Bakker; Willem Marinus Stevels; Ronald Richard Staib
- Inventors: Shane Cyr; Henk Bakker; Willem Marinus Stevels; Ronald Richard Staib
- Web page: https://patentgrep.com/patent/US8771469B2

## CPC

- D21H 17/455: {comprising tertiary amine or being at least partially quaternised}
- C08F 8/44: Preparation of metal salts or ammonium salts
- C08F 220/56: Acrylamide; Methacrylamide
- C08F 226/04: Diallylamine
- C08F 2800/10: as molar percentages
- D21H 11/06: Sulfite or bisulfite pulp
- D21H 17/375: {Poly(meth)acrylamide}
- D21H 17/38: containing crosslinkable groups
- D21H 21/18: Reinforcing agents
- D21H 21/20: Wet strength agents
- 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
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS

## Abstract

This invention relates to resins useful for drainage in papermaking and the process of making paper using the resins. In particular the invention relates to glyoxalated copolymers of acrylamide containing significant amounts of cationic comonomer.

## Claims

### Claim 1

A process for improving drainage in paper making comprising the steps of:
a. forming an aqueous suspension of cellulosic fibers,
b. adding an effective amount of a cationic resin to the aqueous suspension of cellulosic fibers,
c. forming the cellulosic fibers into a sheet, and
d. drying the sheet to produce a paper,
wherein the improvement to drainage is provided by the cationic resin of step b); wherein the cationic resin of step b) comprises the reaction product of a dialdehyde with a copolymer produced from acrylamide, and diallyldimethylammonium chloride, and wherein the diallyldimethylammonium chloride comprises greater than or equal to about 30 mole % of the copolymer before reaction with the dialdehyde.

### Claim 2 (depends on 1)

The process of claim 1 wherein the diallyldimethylammonium chloride comprises greater than or equal to about 40 mole % of the copolymer before reaction with dialdehyde.

### Claim 3 (depends on 1)

The process of claim 1 wherein the dialdehyde comprises glyoxal.

### Claim 4 (depends on 1)

The process of claim 1 wherein the dialdehyde comprises glyoxal and wherein diallyldimethylammonium chloride comprises greater than or equal to 30 mole % of the copolymer before reaction with dialdehyde.

### Claim 5 (depends on 1)

The process of claim 1, wherein the cationic resin has a charge density of greater than 1.0 meq/g.

### Claim 6 (depends on 5)

The process of claim 5, wherein the cationic resin has a charge density of greater than 1.5 meq/g.

### Claim 7 (depends on 6)

The process of claim 6, wherein the cationic resin has a charge density of greater than 2.5 meq/g.

### Claim 8

A process for improving drainage in paper making comprising the steps of:
a. forming an aqueous suspension of cellulosic fibers,
b. adding an effective amount of a cationic resin to the aqueous suspension of cellulosic fibers, and
c. forming the cellulosic fibers into a sheet,
wherein the improvement to drainage is provided by the cationic resin of step b); wherein the cationic resin of step b) comprises the reaction product of a dialdehyde with a copolymer produced from acrylamide, and diallyldimethylammonium chloride, and wherein the diallyldimethylammonium chloride comprises greater than or equal to about 30 mole % of the copolymer before reaction with the dialdehyde.

### Claim 9 (depends on 8)

The process of claim 8 wherein the diallyldimethylammonium chloride comprises greater than or equal to about 40 mole % of the copolymer before reaction with dialdehyde.

### Claim 10 (depends on 8)

The process of claim 8 wherein the dialdehyde comprises glyoxal.

### Claim 11 (depends on 8)

The process of claim 8 wherein the dialdehyde comprises glyoxal and wherein diallyldimethylammonium chloride comprises greater than or equal to 30 mole % of the copolymer before reaction with dialdehyde.

### Claim 12 (depends on 8)

The process of claim 8, wherein the cationic resin has a charge density of greater than 1.0 meq/g.

### Claim 13 (depends on 12)

The process of claim 12, wherein the cationic resin has a charge density of greater than 1.5 meq/g.

### Claim 14 (depends on 13)

The process of claim 13, wherein the cationic resin has a charge density of greater than 2.5 meq/g.