This patent describes an ion-exchange composition comprising synthetic resin support particles, a dispersant attached to the particles to prevent agglomeration, and fine synthetic resin layering particles. The dispersant is irreversibly attached to both the support particles and layering particles, either through covalent bonding or physical entanglement. This creates a complex of support particle-dispersant-layering particle that can be formed by contacting a dispersant with insoluble monomer in an aqueous solution, allowing polymerization to attach the dispersant to resin support particles formed and also attaching it to fine layering particles electrostatically or through covalent bonding.

1. United States Patent [19]
Barreto et al.
[11]
[45]
Patent Number:
Date of Patent:
5,324,752
Jun. 28, 1994
[54] ION-EXCHANGE COMPOSITION
EMPLOYING RESIN A'ITACHMENT TO
DISPERSANT AND METHOD FOR
FORMING THE SAME
[75] Inventors: Victor B. Barreto, Santa Clara;
Stephen Shawn Heberling,
Mountain View; Vernon E.
Summerfelt; Christopher A.
Pohl, both of Union City, all of Calif.
[7g] Assignee: Dionex Corporation, Sunnyvale,
Calif.
[21] App1. No.: 518,293
[22] Filed: May3,1990
Related U.s. Application Data
[63) Continuation of Ser. No. 315,506, Feb. 27, 1989,
abandoned.
[51]
[52]
[58]
Int. CI' COSJ 5/20
U.S. Cl. 521128; 521130;
521131
Field of Search 521128, 30, 31
[56] References Cited
U.S. PATENT DOCUMENTS
4,101,460
4,376,047
4,447,559
4,511,677
7/1978 Smalletal. 521128
3/1983 Pohl 521128
5/1984 Hanaoka et a1. 521128
411985 Horton et al. 521128
4,804,686
4,920,152
4,927,539
211989
411990
5/1990
Regnier et al. 521128
Regnier et al. 521128
Stevens et a1. 521128
FOREIGN PATENT DOCUMENTS
62-204853 9/1987 Japan.
Primary Examiner-Thurman K. Page
Assistant Examiner-P. Kulkosky
Attorney, Agent, or Firm-Flehr, Hohbach, Test,
Albritton & Herbert
[57] ABSTRACT
In accordance with the present invention, an ion-ex-
change composition has been formed which comprises
synthetic resin support particles, dispersant capable of
suspending the support particles in an aqueous medium to
inhibit or prevent agglomeration, and fine synthetic resin
layering particles. In a preferred embodiment, the com-
plex can be formed by contacting a suitable dispersant
with monomer in an aqueous solution in which the mono-
mer is insoluble. Under suitable conditions for suspension
polymerization, the monomer will polymerize to form
resin support particles having dispersant irreversibly
attached to those particles. The dispersant is irreversibly
attached to the synthetic resin support particles, either by
covalent bonding or permanent physical entanglement.
The dispersant is also attached to the fine layering par-
ticles, either by covalent bonding or electrostatic forces.
The result is formation of a support particle-dispersant-
layering particle complex.
12 Claims, No Drawings
IIDIONEX
Presented to
Steven Shaum. !J-(e6erCing