Emulsion copolymer anion exchange resins
AssigneeRohm and Haas Company
InventorBerni P. Chong
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Abstract
Emulsion copolymer particles with diameters less than 1.5 micrometers are functionalized with anion exchange functional groups by a method involving coagulation of the emulsion. Both weakly basic and strongly basic anion exchange resins are prepared from aromatic or acrylic copolymers, and the emulsion coagula may be resuspended to form anion exchange emulsions.
Claims22
Novel, readily dispersible, submicroscopic anion exchange resin particles comprising previously isolated, approximately spherical beads of crosslinked emulsion copolymer derived from polyethylenically unsaturated crosslinking monomers and monoethylenically unsaturated monomers selected from the group consisting of aromatic monoethylenically unsaturated monomers, acrylic monoethylenically unsaturated monomers, and mixtures thereof;
- having diameters within the range from about 0.01 to about 1.5 micrometers;
- and bearing from about 0.7 to about 1.5 anion exchange functional groups per monomer unit.
A process for preparing novel, submicroscopic ion exchange resin particles comprising spherical beads of crosslinked copolymer having diameters within the range from about 0.01 to about 1.5 micrometers and bearing from about 0.7 to about 1.5 anion exchange functional groups per monomer unit, which process comprises the steps of
- (a) emulsion polymerizing a mixture of a major amount of a monoethylenically unsaturated monomer selected from the group consisting of aromatic monoethylenically unsaturated monomers, acrylic monomers, and mixtures thereof, and a minor amount of a polyethylenically unsaturated monomer to form an emulsion of crosslinked copolymer beads,
- (b) coagulating the emulsion to form coagulum particles of the copolymer beads,
- (c) separating the coagulum particles from the emulsion polymerization medium, and
- (d) functionalizing the copolymer beads with anion exchange functional groups.
Novel, submicroscopic particles useful in the preparation of ion exchange materials comprising previously isolated, approximately spherical beads of crosslinked aromatic copolymer having diameters within the range from about 0.01 to about 1.5 micrometers, and bearing from about 0.7 to about 1.5 chloromethyl groups per monomer unit, the chloromethyl groups being introduced into the copolymer by chloromethylation.
Dependencies are inferred from the claim text.