Process for preparing physically stable quaternary ammonium anion exchange resins by chloromethylation and amination in the absence of additional organic solvent

Claim 1

A process for preparing an anion exchange resin comprising the steps of: (a) preparing a crosslinked copolymer by polymerizing a monomer system comprising (i) from about 85 to 99.95 parts by weight of at least one non-polar, aromatic monovinyl hydrocarbon monomer selected from the class consisting of styrene, o-, m, and p-alkylstyrenes, o-, m-, and p-alkoxystyrenes, and vinyl naphthalene, (ii) from about 5 to 0.05 parts by weight of at least one polar functionally-substituted comonomer selected from the group consisting of methyl methacrylate, trimethylol propane trimethacrylate, acrylonitrile and isodecyl methacrylate; and (iii) from about 10 to 0 parts by weight of at least one polyvinyl aromatic hydrocarbon selected from the class consisting of divinyl benzene, divinyl alkyl benzenes, divinyl naphthalenes and trivinyl benzene; (b) haloalkylating said copolymer in the presence of a Lewis acid catalyst wherein the haloalkylating agent is present in an excess quantity and is selected from the group consisting of mono-chloromethyl methyl ether and bis-chloromethyl ether; (c) quenching the haloalkylation reaction, and washing the haloalkylated intermediate copolymer, with water; (d) treating said intermediate copolymer in an aqueous slurry with a tertiary amine to give a quaternary anion exchange resin; and (e) Carrying out steps (a) through (d) in the absence of added organic solvent whereby an anion exchange resin characterized by improved physical stability is obtained.