LOW-SODIUM RESIN

Abstract

Provided is a collection of resin beads,

wherein the resin beads comprise one or more vinyl polymers having quaternary ammonium groups;

wherein cation exchange resin, if present in the collection of resin beads, is present in an amount of 0 to 0.5% by weight based on the weight of the collection of resin beads;

wherein 90 mole % or more of the quaternary ammonium groups are each associated with a hydroxide anion;

wherein sodium, if present, is present in an amount of 0-100 ppb by weight, based on the weight of the collection of resin beads.

Claims

1. A collection of resin beads, wherein the resin beads comprise one or more vinyl polymers having quaternary ammonium groups; wherein cation exchange resin, if present in the collection of resin beads, is present in an amount of 0 to 0.5% by weight based on the weight of the collection of resin beads; wherein 90 mole % or more of the quaternary ammonium groups are each associated with a hydroxide anion; wherein sodium, if present, is present in an amount of 0-100 ppb by weight, based on the weight of the collection of resin beads.

2. The collection of resin beads of claim 1, wherein the vinyl polymer is a vinyl aromatic polymer that has been made by a process comprising polymerization of monomers comprising styrene and divinyl benzene to form a preliminary copolymer, followed by subjecting the preliminary copolymer to one or more chemical reactions to attach quaternary ammonium groups to the preliminary copolymer.

3. The collection of resin beads of claim 1, wherein the vinyl polymer is an acrylic polymer that has been made by a process comprising polymerization of monomers comprising one or more acrylic monomers to form a preliminary copolymer, followed by subjecting the preliminary copolymer to one or more chemical reactions to attach quaternary ammonium groups to the preliminary copolymer.

Description

[0058] The following are examples of the present invention.

[0059] The resin beads used in the following examples are styrene/divinyl benzene copolymers that have attached quaternary ammonium groups. Volume-average bead diameter was between 300 and 1500 micrometer. The resin beads were in hydroxide form; that is, 90 mole % or more of the quaternary ammonium groups were each associated with a hydroxide ion.

COMPARATIVE EXAMPLE 1C

Washing the Resin with Water

[0060] To a round-bottomed flask equipped with an overhead stirrer was added 125 mL of the resin beads followed by 77.65 mL of deionized water. The resulting mixture was agitated for 30 minutes, after which the agitation was stopped, and the aqueous solution was decanted. A 10 mL sample of the resin was removed for sodium analysis by ICP-MS.

EXAMPLE 2

Washing the Resin with Aqueous Solution of Ammonium Hydroxide

[0061] To a round-bottomed flask equipped with an overhead stirrer was added 125 mL of the resin beads followed by 77.65 mL of deionized water and 2.22 mL of a 28% by weight solution of ammonium hydroxide in water. The resulting mixture was agitated for 30 minutes, after which the agitation was stopped, and the aqueous solution was decanted. A 10 mL sample of the resin was removed for sodium analysis by ICP-MS.

EXAMPLE 3

Results of ICP-MS Testing

[0062]

TABLE-US-00001 Sample Sodium concentration Comparative 1C 559 ppb by weight Example 2  27 ppb by weight

[0063] Example 2 had far lower concentration of sodium.