Patents by Inventor Steward E. Purdy

Steward E. 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).

  • Patent number: 5002852
    Abstract: The invention relates to a polyacetylenic recording film of improved resistance to degradation by UV light and increased sensitivity to ionizing radiation and to the process for producing said film which comprises dissolving polyacetylenic imaging crystals in n-butanol before forming a dispersion in a binder material and before coating on a polyester film base.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: March 26, 1991
    Assignee: GAF Chemicals Corporation
    Inventors: David F. Lewis, Mark L. Moskowitz, Steward E. Purdy
  • Patent number: 4970137
    Abstract: This invention concerns a process of mixing a dispersion comprising a substantially crystalline, image receptive polyacetylenic compound in an aqueous non-solvating binder solutions with an effective ripening amount of an organic liquid boiling above 30.degree. C. which is completely miscible with water at least in a proportion of 1:2 part per parts and in which said polyacetylene is soluble for a time and at an elevated temperature sufficient to effect crystalline growth and improved sensitivity to imaging by exposure to a source of radiation.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: November 13, 1990
    Assignee: GAF Chemicals Corporation
    Inventors: David F. Lewis, Steward E. Purdy
  • Patent number: 4784934
    Abstract: The process for improving radiant energy sensitivity of a film base coated with a dispersion of a normally crystalline polyacetylenic compound in a non-solvating liquid which is dried on the film surface; said polyacetylenic compound preferably having at least two conjugated acetylenic linkages and containing from 20 to 60 carbon atoms. The process comprises dispersing said normally crystalline polyacetylenic compound in the non-solvating liquid to a concentration of from about 2 to about 50% polyacetylene crystalline solids and ageing said dispersion by (a) storing at a temperature of between about 0.degree. C. and about 12.degree. C. for a period of from about 1 to about 30 days or (b) freezing said dispersion at a temperature between about -78.degree. C. and about -1.degree. C. for a period of from about 1 to about 75 hours or (c) a combination of the above ageing techniques any or all of which are completed before drying said dispersion on a substrate.
    Type: Grant
    Filed: December 8, 1987
    Date of Patent: November 15, 1988
    Assignee: GAF Corporation
    Inventors: David F. Lewis, Mark L. Moskowitz, Steward E. Purdy
  • Patent number: 4734355
    Abstract: The process for improving radiant energy sensitivity of a film base coated with a dispersion of a normally crystalline polyacetylenic compound in a non-solvating liquid which is dried on the film surface; said polyacetylenic compound preferably having at least two conjugated acetylenic linkages and containing from 20 to 60 carbon atoms. The process comprises dispersing said normally crystalline polyacetylenic compound in the non-solvating liquid to a concentration of from about 2 to about 50% polyacetylene crystalline solids and ageing said dispersion by (a) storing at a temperature of between about 0.degree. C. and about 12.degree. C. for a period of from about 1 to about 30 days or (b) freezing said dispersion at a temperature between about -78.degree. C. and about -1.degree. C. for a period of from about 1 to about 75 hours or (c) a combination of the above ageing techniques any or all of which are completed before drying said dispersion on a substrate.
    Type: Grant
    Filed: December 15, 1986
    Date of Patent: March 29, 1988
    Assignee: GAF Corporation
    Inventors: David F. Lewis, Mark L. Moskowitz, Steward E. Purdy