Process for preparing hydrogels as spherical beads of large size

Patent 4224427 Issued on September 23, 1980. Estimated Expiration Date:

June 1, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

2801992

3509234

3557061

3641199

3716505

3829531

Anaerobic pressure sensitive adhesive composition
Patent #: 3996308
Issued on: 12/07/1976
Inventor: Douek , et al.

Composition useful in making extensible films
Patent #: 4034017
Issued on: 07/05/1977
Inventor: Chang , et al.

High impact corrosion resistant polymers Patent #: 4041104
Issued on: 08/09/1977
Inventor: Selley

Inventors

Assignee

Ciba-Geigy Corporation

Application

No. 05/911636 filed on 06/01/1978

US Classes:

526/93, Group VIII transition metal (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt)525/10, ETHYLENICALLY UNSATURATED REACTANT ADMIXED WITH EITHER (A) A POLYMER DERIVED FROM A SATURATED DI- OR HIGHER ESTER OF A POLYCARBOXYLIC ACID AS SOLE REACTANT, OR (B) REACTION PRODUCT OF ONLY POLYCARBOXYLIC ACIDS OR ANHYDRIDES WITH ONLY COMPOUNDS HAVING AT LEAST TWO HYDROXYL GROUPS AT LEAST ONE OF WHICH IS SATURATED AND WHEREIN THE REACTION PRODUCT FORMED IS NOT AFTERTREATED PRIOR TO ADMIXTURE WITH THE UNSATURATED REACTANT EXCEPT WITH A POLYCARBOXYLIC ACID, POLYCARBOXYLIC ACID ANHYDRIDE, OR A POLYOL, AND WHEREIN NO SOLID POLYMER DERIVED FROM ETHYLENIC REACTANTS ONLY IS MIXED THEREWITH525/404, Mixed with ethylenically unsaturated reactant or polymer therefrom525/424, Mixed with -N=C=X reactant or polymer derived therefrom (X is chalcogen)525/426, Mixed with ethylenically unsaturated reactant or polymer therefrom525/440, Mixed with -N=C=X reactant or polymer derived therefrom (X is chalcogen); or wherein solid polymer is derived from a -N=C=X reactant and also a polycarboxylic acid or derivative and a polyhydroxy reactant525/445, Mixed with ethylenically unsaturated reactant or polymer therefrom525/455, Mixed with ethylenically unsaturated reactant or polymer therefrom525/479, Mixed with ethylenically unsaturated reactant or polymer derived therefrom525/920, POLYURETHANE HAVING TERMINAL ETHYLENIC UNSATURATION525/921, POLYESTER HAVING TERMINAL ETHYLENIC UNSATURATION OTHER THAN POLYESTERURETHANES525/925, POLYMER FROM AT LEAST ONE NONETHYLENIC MONOMER HAVING TERMINAL ETHYLENIC UNSATURATION OTHER THAN POLYURETHANES, POLYESTERS, POLYEPOXIDES, AMINOPLASTS, AND PHENOPLASTS526/172, Transition metal compound has at least one atom of P, S, N or O therein526/221, Material contains inorganic heavy metal compound526/226, Material contains aluminum compound other than aluminum trihalide or nonmetallic organic complex of aluminum trihalide526/227, Material contains peroxy group compound (-O-O-)526/234, Material contains sulfur or inorganic sulfur compound526/237, Material contains metal halide, boron halide or organic complexes thereof, hydrogen halide, elemental halogen, or compound containing only halogen atoms526/259, Nitrogen atom is part of a bridged or fused ring system526/260, 5- or 6-membered nitrogen ring compound having at least one oxygen in the ring526/279, From monomer containing a silicon atom526/318.42, Hydroxyl group526/320, Ether or hydroxy containing526/321, Monomer containing at least two carboxylic acid ester groups526/332, From monomer containing an ether group526/909, POLYMERIZATION CHARACTERIZED BY PARTICLE SIZE OF PRODUCT526/910, SUSPENDING AGENTS526/930WATER SWELLABLE OR HYDROPHILIC

Examiners

Primary: Briggs, Sr., Wilbert J.

Attorney, Agent or Firm

Hall; Luther A. R.

International Classes

A61K 9/16 (20060101)
A61K 9/20 (20060101)
C08F 290/00 (20060101)
C08F 290/06 (20060101)

Abstract

The disclosure describes an improved process for the preparation of uniform, spherical beads of up to 5 mm diameter of a crosslinked, water-insoluble hydrogel by suspension polymerization in a concentrated aqueous salt solution of 95-30% by weight of a monoolefinic water-soluble monomer containing at least 5% of a hydroxy substituted hydrophilic vinyl monomer with 5-70% by weight of a terminal diolefinic macromer crosslinking agent in the presence of water-insoluble, gelatinous, strong water-bonding inorganic metal hydroxides as suspending agents in the absence of excess alkali. The hydrogels have a host of pharmaceutical and industrial uses.