Water-swellable, bead copolymer

Claim 2

A water-swellable, cross-linked bead copolymer prepared by the method comprising: a. dissolving a monomer mixture consisting essentially of

Claim 3

an ethylenically-unsaturated radical-polymerizable comonomer having a glycidyl group, 2. a cross-linking comonomer having at least two radical-polymerizable α, β-carbon double bonds, but otherwise free of the functional groups found in monomer (1), 3. a radical-polymerizable water-soluble mono-unsaturated comonomer, comonomers (1), (2), and (3) constituting from about 50 to 100 mol percent of the monomer mixture with the balance, if any, being 4. a water-insoluble radical-polymerizable mono-unsaturated compound, comonomer (1) comprising at least 2 mol percent, comonomer (2) comprising 0.2 to 5 mol percent, and comonomer (3) comprising at least 10 mol percent of the monomer mixture, in from 20 to 200 percent, by weight of the monomer mixture, of a non-aqueous solvent for said monomer mixture; b. combining the solution with a free radical-forming initiator soluble in said solution; c. suspending the resulting solution, in the form of droplets, in a continuous phase of a non-polar organic liquid which is immiscible with said non-aqueous solvent and is not a solvent for said monomer or said initiator; d. polymerizing said monomer mixture at a temperature at which said initiator forms free radicals, whereby said bead copolymer is formed; and e. separating said bead copolymer from said continuous phase of organic liquid.

Claim 4

an ethylenically-unsaturated radical-polymerizable comonomer having a glycidyl group, 2. a cross-linking comonomer having at least two radical-polymerizable α, β-carbon double bonds, but otherwise free of the functional groups found in monomer (1), 3. a radical-polymerizable water-soluble mono-unsaturated comonomer, comonomers (1), (2), and (3) constituting from about 50 to 100 mol percent of the monomer mixture with the balance, if any, being 4. a water-insoluble radical-polymerizable mono-unsaturated compound, comonomer (1) comprising at least 2 mol percent, comonomer (2) comprising 0.2 to 5 mol percent, and comonomer (3) comprising at least 10 mol percent of the monomer mixture, in from 20 to 200 percent, by weight of the monomer mixture, of a non-aqueous solvent for said monomer mixture; b. combining the solution with a free radical-forming initiator soluble in said solution; c. suspending the resulting solution, in the form of droplets, in a continuous phase of a non-polar organic liquid which is immiscible with said non-aqueous solvent and is not a solvent for said monomer or said initiator; d. polymerizing said monomer mixture at a temperature at which said initiator forms free radicals, whereby said bead copolymer is formed; and e. separating said bead copolymer from said continuous phase of organic liquid.

Claim 5

A copolymer as claimed in claim 1 which is washed with an anhydrous solvent after separation from said continuous phase of organic liquid.

Claim 6

A copolymer as claimed in claim 2 which is washed with acetone after separation from said continuous phase of organic liquid.

Claim 7

A copolymer as in claim 1 wherein comonomer (1) is an ester or ether formed between a glycidyl alcohol and an unsaturated carboxylic acid or an unsaturated alcohol, respectively.

Claim 8

A copolymer as in claim 1 wherein comonomer (1) is allyl glycidyl ether or an acrylate or methacrylate ester of an aliphatic or cycloaliphatic glycidyl alcohol or glycidyl ether alcohol having 3 to 18 carbon atoms.

Claim 9

A copolymer as in claim 1, wherein comonomer (2) is a mono- or lower polyethylene glycol dimethacrylate or diacrylate, divinyl benzene, triallyl cyanurate, methylene-bisacrylamide or methacrylamide, or a combination thereof.

Claim 10

A copolymer as in claim 6, wherein comonomer (2) is ethylene- or triethylene glycol dimethacrylate.

Claim 11

A copolymer as in claim 1, wherein comonomer (3) is a vinyl or vinylidene compound containing an amido, hydroxyl, carboxyl, tertiary amino, quaternary ammonium or sulfonic acid group.

Claim 12

A copolymer as in claim 8, wherein comonomer (3) is a vinyl or vinylidene compound containing an amido group.

Claim 13

A copolymer as in claim 1, wherein comonomer (3) is acryl- or methacrylamide, vinyl pyrrolidone, ethylene glycol- or propylene glycol monoacrylate or monomethacrylate, acrylic- or methacrylic acid, dialkylaminoethyl acrylate or methacrylate with 1 to 4 carbon atoms in the alkyl substituents, vinyl sulfonic acid, sulfoethyl acrylate or methacrylate, a salt thereof, or a combination thereof.

Claim 14

A copolymer as in claim 1, wherein the content of comonomer (3) is more than 20% by weight.

Claim 15

A copolymer as in claim 11, wherein the content of comonomer (3) is from 50 to 80% by weight.