# US 4,391,878 A · Wet strength resins

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- Number: US 4,391,878 A
- Document ID: US4391878A
- Status: Granted
- Kind: A
- Application number: 06/286,078
- Filed: 1981-07-24
- Granted: 1983-07-05
- Earliest claimed: 1981-07-24
- Assignees: Scott Paper Company
- Inventors: John E. Drach
- Web page: https://patentgrep.com/patent/US4391878A

## CPC

- D21H 17/43: Carboxyl groups or derivatives thereof
- D21C 5/02: Working-up waste paper (mechanical part D21B1/08, D21B1/32)
- D21H 17/45: Nitrogen-containing groups
- Y02W 30/64: Paper recycling
- Y10T 428/31783: Paper or wood
- 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
- D21C: PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Water soluble wet strength resins containing maleamic acid and at least one other ethylenically unsaturated monomer, such as vinyl esters, olefins, acrylic and/or methyacrylic acids and/or their esters and/or their amindes are useful in the preparation of paper products having improved, off-machine dry strength and wet strength properties.

## Claims

### Claim 1

A cellulosic fibrous web wherein the cellulose fibers are chemically modified by a cross-linking reaction with a wet strength resin comprising a water soluble copolymer comprised of (A) a half-acid, half-amide corresponding to the following general formula: ##STR6## wherein R' is H and R is a hydrocarbon chain containing a double bond which has radically polymerized with (B) at least one other ethylenically unsaturated monomer.

### Claim 2 (depends on 1)

The web in accordance with claim 1 wherein said copolymer is present in an amount equal to 0.1 to 5% based on the weight of the fiber in the web.

### Claim 3 (depends on 1)

The web according to claim 1 wherein the half-acid, half-amide corresponding to the general formula is maleamic acid.

### Claim 4 (depends on 1)

The web according to claim 1 wherein the half-acid, half-amide corresponding to the general formula is fumaramic acid.

### Claim 5 (depends on 1)

The web according to claim 1 wherein the half-acid, half-amide corresponding to the general formula is itaconamic acid.

### Claim 6 (depends on 1)

The web according to claim 1 wherein the other ethylenically unsaturated monomer comprises a vinyl ester of an aliphatic acid having one to ten carbon atoms.

### Claim 7 (depends on 6)

The web according to claim 6 wherein said monomer is vinyl acetate.

### Claim 8 (depends on 7)

The web according to claim 7 wherein the copolymer further includes esters of acrylic or methacrylic acids.

### Claim 9 (depends on 1)

The web according to claim 1 wherein component (B) of the copolymer comprises an ethylenically unsaturated, basic nitrogen containing monomer.

### Claim 10 (depends on 1)

The web according to claim 1 wherein the half-acid, half-amide comprises from 1 to 10% by weight of the copolymer.