Polycationic latices of dimethylaminopropyl-acrylamide, and their use of as sludge dewatering agents and/or paper retention aids
AssigneeNalco Chemical Company
InventorWun T. Tai
Life of this patent
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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.
Claims7
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.
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.
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.
Dependencies are inferred from the claim text.