Patents by Inventor William G. Chiang

William G. Chiang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5478894
    Abstract: This invention is directed to a recurring polymeric moiety of the following formula: ##STR1## wherein R is independently selected from hydrogen and C.sub.1 to C.sub.4 alkyl; Y is independently selected from O and NH; and X is independently selected from Cl, F, Br, I, NO.sub.3, HSO.sub.4 and H.sub.2 PO.sub.4.Polymers of the above structure may be crosslinked by treating the polymer with a base and heating it.
    Type: Grant
    Filed: July 2, 1993
    Date of Patent: December 26, 1995
    Assignee: Hoechst Celanese Corporation
    Inventors: William G. Chiang, Joy L. McCrickard
  • Patent number: 5132383
    Abstract: The present invention provides a copolymer comprising the polymerization product of two or more vinyl monomers wherein one of the monomers is a mixture of 3-methacryloyloxy-2-hydroxypropyltrimethylammonium halide and 2-methacryloyloxy-3-hydroxypropyltrimethylammonium halide salt. The copolymer has an intrinsic viscosity greater than about 5 dl/g. The preferred copolymer comprises the polymerization product of acrylamide and a mixture of 3-methacryloyloxy-2-hydroxypropyltrimethylammonium chloride and 2-methacryloyloxy-3-hydroxypropyltrimethylammonium chloride. The copolymers of the present invention are particularly useful as flocculants.
    Type: Grant
    Filed: December 26, 1989
    Date of Patent: July 21, 1992
    Assignee: Polypure, Inc.
    Inventors: Eric H. Larson, Benjamin Shultes, III, William G. Chiang
  • Patent number: 5008444
    Abstract: The preparation of 3-(R)acryloyloxy-2-hydroxypropyltrialkylammonium halide monomer is enhanced by carrying out the reaction in a media which is a non-solvent for the monomer, but is a solvent for the reactants.
    Type: Grant
    Filed: December 26, 1989
    Date of Patent: April 16, 1991
    Assignee: Polypure, Inc.
    Inventors: William G. Chiang, Richard M. Jobbins, Michael P. Popule
  • Patent number: 4888396
    Abstract: Novel cationic polymers are provided by reaction of high molecular weight polymers and copolymers of acrylamide with an alkyl epoxide compound such as glycidyldialkylamine or glycidyltrialkylammonium salt to form polymer chain units containing e.g. pendant (N-2-hydroxypropyl) dialkylamine groups of their trialkylammonium salts. Processes for making the graft copolymers are provided in which the reaction is carried out while maintaining the reaction mixture in gel form by swelling the starting solid polymer with a solvent mixture.The reaction may be carried out in a homogeneous reaction environment or in a heterogeneous reaction environment by dispersing the starting solid polymer in an inert liquid that is a non-solvent for both the polymer and the salt. The polymeric products of the reaction may be hardened with a suitable liquid, such as isopropanol, to a solid particulate material.
    Type: Grant
    Filed: June 8, 1988
    Date of Patent: December 19, 1989
    Assignee: Polypure, Inc.
    Inventors: Herbert K. Reimschuessel, William G. Chiang, George J. W. Tichenor