Patents by Inventor David F. Purdy

David F. Purdy 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).

  • Publication number: 20100264361
    Abstract: Solid water treatment compositions are provided comprising (a) a halogen-containing source; (b) a boron-containing source; and (c) a polyphosphate-containing source. Methods for their use are also provided.
    Type: Application
    Filed: October 19, 2009
    Publication date: October 21, 2010
    Applicant: CHEMTURA CORPORATION
    Inventors: Nidhi Rawat, David F. Purdy, Michael J. Engram
  • Patent number: 7780857
    Abstract: A method for reducing the halogen off-gassing rate in a solid water treatment halogen-containing composition is provided comprising forming a solid water treatment halogen-containing composition comprising (a) a halogen containing source; (b) a boron-containing source and (c) a polyphosphate-containing source.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: August 24, 2010
    Assignee: Chemtura Corporation
    Inventors: Nidhi Rawat, David F. Purdy, Michael J. Engram
  • Publication number: 20100055203
    Abstract: Solid water treatment compositions are provided comprising (a) a halogen-containing source; (b) a boron-containing source; and (c) a polyphosphate-containing source. Methods for their use are also provided.
    Type: Application
    Filed: October 19, 2009
    Publication date: March 4, 2010
    Applicant: CHEMTURA CORPORATION
    Inventors: Nidhi Rawat, David F. Purdy, Michael J, Engram
  • Patent number: 7625496
    Abstract: Solid water treatment compositions are provided comprising (a) a halogen-containing source; (b) a boron-containing source; and (c) a polyphosphate-containing source. Methods for their use are also provided.
    Type: Grant
    Filed: October 18, 2007
    Date of Patent: December 1, 2009
    Assignee: Chemtura Corporation
    Inventors: Nidhi Rawat, David F. Purdy, Michael J. Engram
  • Patent number: 6863830
    Abstract: A method for treating a recirculating water system which comprises introducing into said water system a multifunctional, multilayer tablet, wherein the multilayer tablet comprises a fast dissolving layer and a slow dissolving layer, wherein said fast dissolving layer releases a combination of active ingredients including a member selected from the group consisting of lithium hypochlorite, calcium hypochlorite, trichloroisocyanuric acid (TCCA), anhydrous sodium dichloroisocyanurate, sodium persulfate, potassium persulfate, potassium monopersulfate, sodium monopersulfate, and mixtures thereof, and at least one of a clarifier, chelating agent, sequesterant, algaestat, water softener, algaecide, corrosion inhibitor, scale inhibitor, flocculent, disintegrant, dispersant, colorant, dissolution control agent, fragrance, or surfactant and, wherein said slow dissolving layer includes a member selected from the group consisting of trichloroisocyanuric acid (TCCA), calcium hypochlorite, 1,3-dichloro-5,5-dimethylhydantoi
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: March 8, 2005
    Assignee: BioLab Services, Inc.
    Inventors: David F. Purdy, Tian Lan, Michael B. Clark, Thomas M. Lachocki