# US 4,391,932 A · Polycationic latices of dimethylaminopropyl-acrylamide, and their use of as sludge dewatering agents and/or paper retention aids

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- Number: US 4,391,932 A
- Document ID: US4391932A
- Status: Granted
- Kind: A
- Application number: 06/341,971
- Filed: 1982-01-22
- Granted: 1983-07-05
- Earliest claimed: 1982-01-22
- Assignees: Nalco Chemical Company
- Inventors: Wun T. Tai
- Web page: https://patentgrep.com/patent/US4391932A

## CPC

- D21H 17/455: {comprising tertiary amine or being at least partially quaternised}
- C02F 1/54: using organic material
- C08F 8/32: by reaction with amines
- D21H 17/37: Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
- C08F 2800/20: as weight or mass percentages
- 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
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS

## Abstract

Water-in-oil emulsions of copolymers of acrylamide and dimethylaminopropylacrylamide are disclosed. These polymers find use as retention aids in the manufacture of paper and as dewatering agents for municipal and industrial aqueous waste materials. Methods of preparing these polymers are disclosed.

## Claims

### Claim 1

A water-in-oil emulsion of an acrylamide-dimethylaminopropylacrylamide copolymer having been prepared by the steps comprising:
A. forming a water-in-oil emulsion of an acrylamide-acrylonitrile copolymer, said water-in-oil emulsion containing:
a. 5-60% by weight acrylamide-acrylonitrile copolymer containing 1-50% by weight acrylonitrile;
b. 20-90% water;
c. 5-75% of an inert hydrophobic organic liquid; and
d. 0.1-21% water-in-oil emulsifying agent;
B. reacting said water-in-oil emulsion of the acrylamide-acrylonitrile copolymer with dimethylamino-propylamine in a molar ratio of dimethylaminopropylamine to acrylonitrile of from 1:1 to 0.1:1;
C. recovering a readily invertible water-in-oil emulsion of an acrylamide-dimethylaminopropyl acrylamide copolymer.

### Claim 2 (depends on 1)

The water-in-oil emulsion of an acrylamide:dimethylaminopropyl acrylamide copolymer of claim 1 wherein the dimethylaminopropylamine is reacted with the acrylamide:acrylonitrile copolymer at a temperature of from 20.degree.-80.degree. C.

### Claim 3 (depends on 1)

The water-in-oil emulsion of an acrylamide-dimethylaminopropylacrylamide copolymer of claim 1 wherein the water-in-oil emulsion of the acrylamide:acrylonitrile copolymer contains, prior to reaction with dimethylaminopropylamine:
A. 25-35% acrylamide-acrylonitrile copolymer, said copolymer containing 10-40% by weight acrylonitrile;
B. 30-55% by weight water;
C. 20-30% inert hydrophobic liquid;
D. 1.2-10% water-in-oil emulsifying agent.

### Claim 4 (depends on 1)

The water-in-oil emulsion of an acrylamide:dimethylaminopropylacrylamide copolymer of claim 1 wherein the acrylamide-acrylonitrile copolymer has a weight ratio of acrylamide to acrylonitrile of from 95:5 to 50:50.

### Claim 5 (depends on 1)

The water-in-oil emulsion of acrylamide-dimethylaminopropyl acrylamide copolymer of claim 1, wherein said copolymer having a molecular weight of greater than 1,000,000.

### Claim 6

A method for the preparation of a water-in-oil emulsion of an acrylamide-dimethyl amino propyl acrylamide polymer comprising the steps of:
A. forming a water-in-oil emulsion of an acrylamide-acrylonitrile copolymer, said water-in-oil emulsion containing:
a. 5-60% by weight acrylamide-acrylonitrile copolymer containing 1-50% by weight acrylonitrile;
b. 20-90% water;
c. 5-75% of an inert hydrophobic organic liquid; and
d. 0.1-21% water-in-oil emulsifying agent;
B. reacting said water-in-oil emulsion of the acrylamide-acrylonitrile copolymer with dimethylamino-propylamine in a molar ratio of dimethylaminopropylamine to acrylonitrile of from 1:1 to 0.1:1;
C. recovering a readily invertible water-in-oil emulsion of an acrylamide-dimethylaminopropyl acrylamide copolymer.

### Claim 7

A method for the preparation of a water-in-oil emulsion of an acrylamide-dimethyl amino propyl acrylamide polymer comprising the steps of:
A. Forming a water-in-oil emulsion of an acrylamide-acrylonitrile copolymer, said water-in-oil emulsion containing:
a. 25-35% by weight acryamide-acrylonitrile copolymer containing 10-40% by weight acrylonitrile;
b. 30-55% water;
c. 20-30% of an inert hydrophobic organic liquid; and
d. 1.2-10% water-in-oil emulsifying agent;
B. reacting said water-in-oil emulsion of the acrylamide-acrylonitrile copolymer with dimethylamino-propylamine in a molar ratio of dimethylaminopropylamine to acrylonitrile of from 1:1 to 0.1:1.