Refluxing water-in-oil emulsion process for preparing water-soluble polyelectrolyte particles

Claim 2

An inverse emulsion polymerization process for the production of finely divided, water-soluble polymeric particles which comprises heating to reflux under vigorous agitation of from about 200 to about 700 rotations per minute a water-in-oil-inverse emulsion of a surfactant, a free radical initiator, at least one water soluble, oil-insoluble ethylenically unsaturated monomer adapted to polymerize under refluxing conditions, oil, and water wherein the percent by weight of oil is higher than the percent by weight of water, said oil and water being adapted to form an azeotropic boiling mixture, to cause said monomer to polymerize within aqueous droplets dispersed in the emulsion to form finely divided particles and to cause water to be simultaneously separated therefrom, and recovering finely divided water-soluble polymeric particles.

Claim 3

The process of claim 1 wherein the ethylenically unsaturated water-soluble monomers of the present process are selected from the group consisting of acrylamide, methacrylamide, acrylic acid, alkali metal salts of acrylic acid, methacrylic acid, dimethylaminoethyl methacrylate, vinylbenzyl trimethylammonium chloride, alkali metal and ammonium salts of 2-sulfoethylacrylate, sodium styrene sulfonate, 2-aminoethylmethacrylate hydrochloride, alkali metal and ammonium salts of vinylbenzyl sulfonates and mixtures thereof.

Claim 4

The process of claim 2 wherein said monomer includes acrylamide or methacrylamide.

Claim 5

The process of claim 2 wherein the free radical polymerization initiators include peroxide catalysts and redox systems.

Claim 6

The process of claim 1 wherein said refluxing takes place at a temperature of from about 50 to about 120° C. and at a pressure of from about 15 to about 1500 millimeters of mercury and wherein said particulate product has an average particle diameter of from about 100 to about 2000 microns.

Claim 7

An inverse emulsion polymerization process for the production of finely divided, water-soluble polymeric particles which comprises heating to reflux under vigorous agitation of from about 250 to about 600 rotations per minute a water-in-oil inverse emulsion of from about 1 to about 10 percent by weight of a surfactant, from about 0.002 to about 0.01 percent by weight of a free radical initiator, from about 2 to about 60 percent by weight of at least one water-soluble, oil-insoluble ethylenically unsaturated monomer adapted to polymerize under refluxing conditions, from about 30 to about 80 percent by weight oil, and from about 5 to about 35 percent by weight water, wherein the percent by weight of oil is higher than the percent of weight of water and wherein all percentages are by weight of the total reaction mixture, said oil and water being adapted to form an azeotropic boiling mixture, to cause said monomer to polymerize within aqueous droplets dispersed in the emulsion to form finely divided particles and to cause water to be simultaneously separated therefrom, and recovering finely divided, water-soluble polymeric particles.

Claim 8

An inverse emulsion polymerization process for the production of finely divided, water-soluble polymeric particles which comprises heating to reflux under vigorous agitation of from about 250 to about 600 rotations per minute a water-in-oil inverse emulsion of from about 1 to about 10 percent by weight of a surfactant, from about 0.002 to about 0.01 percent by weight of a free radical initiator, from about 2 to about 60 percent by weight of at least one water-soluble, oil-insoluble ethylenically unsaturated monomer adapted to polymerize under refluxing conditions, from about 30 to about 80 percent by weight oil, and from about 5 to about 35 percent by weight water, wherein the percent by weight of oil is higher than the percent of weight of water and wherein all percentages are by weight of the total reaction mixture, said oil and water being adapted to form an azeotropic boiling mixture, to cause said monomer to polymerize within aqueous droplets dispersed in the emulsion to form finely divided particles and to cause water to be simultaneously separated therefrom, and recovering finely divided, water-soluble polymeric particles.

Claim 9

The process of claim 6 wherein said refluxing takes place at a temperature of from about 75° to about 115° C. and at a pressure of from about 300 to about 800 millimeters of mercury.

Claim 10

The process of claim 7 wherein said surfactant is selected from the class consisting of sodium monooleate, sodium monostearate, diglycerol monostearate, and their ethoxylated derivatives, said radical initiator is selected from the class consisting of t-butyl hydroperoxide, ammonium persulfate, and potassium persulfate, said ethylenically unsaturated monomer is selected from the class consisting of acrylamide, methacrylamide, acrylic acid, alkali metal salts of acrylic acid, methacrylic acid, and dimethylaminoethyl methacrylate, and said oil is selected from the class consisting of toluene, xylene, o-dichlorobenzene, monochlorobenzene, ethylene dichloride, and perchloroethylene.

Claim 11

The process of claim 7 wherein said ethylenically unsaturated monomer comprises a mixture of acrylamide and dimethylaminoethyl methacrylate.

Claim 12

The process of claim 1 wherein said oil is selected from the group consisting of toluene, xylene, o-dichlorobenzene, monochlorobenzene, ethylene dichloride, and perchloroethylene.

Claim 13

An inverse emulsion polymerization process for the production of finely divided, water-soluble polymeric particles which comprises heating to reflux under vigorous agitation of from about 300 to about 400 rotations per minute, at a temperature of from about 85° to about 110° C. and at a pressure of from about 700 to about 790 millimeters of mercury a water-in-oil inverse emulsion of from about 1.5 to about 6 percent by weight of sorbitan monooleate, from about 0.004 to about 0.008 percent by weight of ammonium persulfate, from about 5 to about 30 percent by weight of a mixture of acrylamide and dimethylaminoethyl methacrylate, from about 50 to about 75 percent by weight toluene, and from about 10 to about 25 percent by weight water wherein all percentages are by weight of the total reaction mixture, said oil and water being adapted to form an azeotropic boiling mixture, to cause said acrylamide and dimethylaminoethyl methacrylate to polymerize within aqueous droplets dispersed in the emulsion in the form of finely divided particles and to cause water to be simultaneously separated therefrom, and recovering finely divided, water-soluble polymeric particles.

Claim 14

An inverse emulsion polymerization process for the production of finely divided, water-soluble polymeric particles which comprises heating to reflux under vigorous agitation of from about 300 to about 400 rotations per minute, at a temperature of from about 85° to about 110° C. and at a pressure of from about 700 to about 790 millimeters of mercury a water-in-oil inverse emulsion of from about 1.5 to about 6 percent by weight of sorbitan monooleate, from about 0.004 to about 0.008 percent by weight of ammonium persulfate, from about 5 to about 30 percent by weight of a mixture of acrylamide and dimethylaminoethyl methacrylate, from about 50 to about 75 percent by weight toluene, and from about 10 to about 25 percent by weight water wherein all percentages are by weight of the total reaction mixture, said oil and water being adapted to form an azeotropic boiling mixture, to cause said acrylamide and dimethylaminoethyl methacrylate to polymerize within aqueous droplets dispersed in the emulsion in the form of finely divided particles and to cause water to be simultaneously separated therefrom, and recovering finely divided, water-soluble polymeric particles.

Claim 15

The process of claim 11 wherein the acrylamide and dimethylaminoethyl methacrylate are present in a weight ratio of acrylamide to dimethylaminoethyl methacrylate of from about 20:1 to about 1:1.