# US 4,400,502 A · Readily dispersible anionic, water-soluble cellulose derivatives and a method for their preparation

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- Number: US 4,400,502 A
- Document ID: US4400502A
- Status: Granted
- Kind: A
- Application number: 06/372,357
- Filed: 1982-04-27
- Granted: 1983-08-23
- Earliest claimed: 1982-04-27
- Assignees: Hercules Incorporated
- Inventors: Thomas G. Majewicz
- Web page: https://patentgrep.com/patent/US4400502A

## CPC

- C08B 11/20: Post-etherification treatments of chemical or physical type, {e.g. mixed etherification in two steps}, including purification
- C08L 1/28: Alkyl ethers
- C08B: POLYSACCHARIDES; DERIVATIVES THEREOF (polysaccharides containing less than six saccharide radicals attached to each other by glycosidic linkages C07H; fermentation or enzyme-using processes C12P19/00; sugar industry C13; production of cellulose D21)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

Anionic, water-soluble cellulose ethers which are treated with a mixture of glyoxal and a sodium borate, preferably borax, readily disperse in aqueous solutions without clumping or agglomerating. These treated compounds can be formed by contacting an organic slurry of an anionic, water-soluble cellulose ether with an aqueous solution of glyoxal and a sodium borate, recovering the product and then drying it.

## Claims

### Claim 1

A method for making a dispersible, anionic, water-soluble cellulose ether comprising:
(a) contacting a particulate anionic water-soluble cellulose ether with an aqueous medium prepared from water, glyoxal, and a sodium borate to form a product;
(b) recovering the resulting product; and
(c) drying the recovered product.

### Claim 2 (depends on 1)

The method of claim 1 wherein the aqueous sodium borate-glyoxal solution contains sufficient sodium borate to complex substantially all the glyoxal.

### Claim 3 (depends on 1)

The method of claim 1 wherein the sodium borate is borax.

### Claim 4 (depends on 3)

The method of claim 3 wherein the borax to glyoxal ratio is from about 0.5:1 to about 5:1, based on weight.

### Claim 5 (depends on 3)

The method of claim 3 wherein the borax to glyoxal ratio is from about 1:1 to about 2:1, based on weight.

### Claim 6 (depends on 1)

The method of claim 1 wherein the aqueous sodium borate-glyoxal solution contains from about 0.1 to 1.0 wt% glyoxal based on the weight of anionic water-soluble cellulose ether.

### Claim 7 (depends on 1)

The method of claim 1 wherein the aqueous sodium borate-glyoxal solution contains from about 0.2 to about 0.5 wt% glyoxal based on the weight of anionic water-soluble cellulose ether.

### Claim 8 (depends on 1)

The method of claim 1 wherein the cellulose ether is carboxymethyl cellulose.

### Claim 9 (depends on 1)

The method of claim 1 wherein the cellulose ether is carboxymethyl hydroxyethyl cellulose.

### Claim 10

A particulate anionic water-soluble cellulose ether which has been treated with an aqueous medium prepared from water and the reaction product of glyoxal and a sodium borate.

### Claim 11 (depends on 10)

The particulate anionic water-soluble cellulose ether of claim 10 wherein the sodium borate is borax.