Patents by Inventor Derek W. Edwards

Derek W. Edwards 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).

  • Purification of 1,1,1,2-tetrafluoroethane
    Patent number: 5160499
    Abstract: A process for the removal of 1-chloro-2,2-difluoroethylene from 1,1,1,2-tetrafluoroethane which process comprises contacting 1,1,1,2-tetrafluoroethane containing 1-chloro-2,2-difluoroethylene with a zeolite containing strontium cations.The zeolite containing stronium cations may be produced by ion-exchange with a commercially available zeolite, for example an A-type zeolite or a chabazite.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: November 3, 1992
    Assignee: Imperial Chemical Industries PLC
    Inventor: Derek W. Edwards
  • Production of vinylidene fluoride
    Patent number: 5110996
    Abstract: Production of vinylidene fluoride by reacting dichlorodifluoromethane with methane in a heated reactor element containing a non-metallic packing material which is stable at the operating temperatures of the process, wherein the reactor element subjects the gaseous reactants to a temperature within the range 500.degree. C. to 1200.degree. C. and wherein the calculated residence time for the gaseous reactants in the reaction zone is within the range of from 0.1 to 10.0 seconds.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: May 5, 1992
    Assignee: Imperial Chemical Industries PLC
    Inventor: Derek W. Edwards
  • High-solids alkyl ketene dimer dispersion
    Patent number: 4861376
    Abstract: Stable high solids dispersions of ketene dimer are provided by using water soluble carboxylic acid, e.g. acetic acid with cationic starch, sodium lignin sulfonate and aluminum sulfate.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: August 29, 1989
    Assignee: Hercules Incorporated
    Inventors: Derek W. Edwards, David F. Townsend
  • Photooxidation process
    Patent number: 4152230
    Abstract: A photochemically initiated oxidation process for organic materials using only catalytic quantities of the photochemical agent by conducting the reaction in the presence of a compound of a variable valency metal (especially copper) in order to trap the photochemically produced radicals. The spent metal compound can be regenerated ready for trapping further radicals by contact with a source of oxygen.
    Type: Grant
    Filed: January 25, 1977
    Date of Patent: May 1, 1979
    Assignee: Imperial Chemical Industries Limited
    Inventors: Derek W. Edwards, Graham H. Jones