Patents by Inventor Douglas G. Hamilton

Douglas G. Hamilton 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: 6114437
    Abstract: Polychromic articles are manufactured by solvent casting polycarbonate resins previously mixed with a photochromic dye and evaporating the solvent. The films produced can be insert injection molded with polycarbonate substrates to obtain photochromic articles.
    Type: Grant
    Filed: February 4, 1998
    Date of Patent: September 5, 2000
    Assignee: General Electric Company
    Inventors: Michael W. Brown, Douglas G. Hamilton, Rodney L. Michel, John G. Skabardonis
  • Patent number: 6013686
    Abstract: The present invention relates generally to blowing agent concentrates for forming porous, molded thermoplastic items, and, more particularly to blowing agent concentrates that are compatible with polycarbonate homopolymers, but which can be extruded without causing thermal decomposition of the blowing agent.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: January 11, 2000
    Assignee: General Electric Company
    Inventors: Douglas G. Hamilton, Steven R. Peak, Randall A. Reed
  • Patent number: 5616641
    Abstract: An improved floatation separation process wherein the improvement comprises dissolving in a floatation bath sufficient alkali metal salt or alkaline earth metal salt of a phosphate, a pyrophosphate, a metaphosphate or a polyphosphate to provide a concentration greater than 1.0 grams per cubic centimeter and generally about 1.05 to about 1.6. g/cc. A particular salt is sodium dihydrogen phosphate. Preferably, the floatation process is employed to separate physical mixtures of plastic parts.
    Type: Grant
    Filed: May 28, 1996
    Date of Patent: April 1, 1997
    Assignee: General Electric Company
    Inventors: Jeffrey D. Basch, Robert R. Gallucci, Douglas G. Hamilton
  • Patent number: 5554674
    Abstract: A flame retardant thermoplastic composition of at least one thermoplastic resin, at least about 20 percent by weight of an inorganic filler, and effective flame retarding amount of a metal acid pyrophosphate, and optionally, an impact modifier, an anti-drip agent and/or a second flame retardant.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: September 10, 1996
    Assignee: General Electric Company
    Inventor: Douglas G. Hamilton
  • Patent number: 5502119
    Abstract: A polyester-polycarbonate composition comprising (A) at least one polyester prepared by the reaction of at least one alkanediol with at least one dicarboxylic acid or dialkyl ester thereof in the presence of a metallic catalyst, (B) at least one polycarbonate, (C) at least one organosilicate, the organosilicate being present in an amount effective to inhibit ester-carbonate interchange in the composition, optionally, (D) an organic or inorganic colorant, (E) an impact modifier, and (F) a stabilizer. A method for stabilizing polyester-polycarbonate compositions against ester-carbonate interchange is also provided.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: March 26, 1996
    Assignee: General Electric Company
    Inventor: Douglas G. Hamilton
  • Patent number: 5446112
    Abstract: A melt process for the synthesis of poly(metal aromatic esters) resins is provided. The process provides volatile byproducts which can be easily separated from the desired poly(metal aromatic ester) resin product. The poly(metal aromatic ester) resins are particularly useful as polymer additives for the purpose of such things as scavenging traces of water, activating sulphur accelerator crosslinking systems, and producing intumescent and polyester/metal oxide formulations.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: August 29, 1995
    Assignee: General Electric Company
    Inventors: Douglas G. Hamilton, Christopher M. Hawkins
  • Patent number: 5371123
    Abstract: Polyester resins, optionally in combination with a polycarbonate, flame retarded with a halogenated bis-imide flame retardant agent and modified with a glass fiber reinforcing agent treated with a coating agent selected from certain polyepoxides and/or polyolefins exhibit markedly improved color characteristics.
    Type: Grant
    Filed: December 22, 1992
    Date of Patent: December 6, 1994
    Assignee: General Electric Company
    Inventors: Robert R. Gallucci, Leslie J. Goff, Douglas G. Hamilton
  • Patent number: 5081176
    Abstract: Aromatic thermoplastic compositions are provided having reduced total smoke released upon burning in accordance with ASTM-EO96. The aromatic thermplastic compositions utilize an effective amount of tin monoxide, and which are substantially free of antimony trioxide and brominated organic flame retardant resins. Minor amounts of polytetrafluoroethylene resin and glass fiber also contribute to the reduction of total smoke release upon burning of the thermoplastic polyester.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: January 14, 1992
    Assignee: General Electric Company
    Inventor: Douglas G. Hamilton
  • Patent number: 5034474
    Abstract: Aromatic polyesters, such as polybutylene-terephthalate, have been found to have a reduced tendency to drip during burning, if an effective amount of a polyhydroorganosiloxane is incorporated into the polyester. A further enhancement in the non-drip behavior is achieved by the addition of an effective amount of a transition metal oxide, such as a platinum oxide, or by the modification of the polyhydroorganosiloxane with an aliphatic alcohol such as benzyl alcohol in the presence of a catalytic amount of an alkali metal alkoxide.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: July 23, 1991
    Assignee: General Electric Company
    Inventor: Douglas G. Hamilton