Patents by Inventor David G. Keyes

David G. Keyes 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).

  • Method for making polyetherimides
    Patent number: 4330666
    Abstract: A method is provided for making polyetherimides based on the use of certain amphoteric catalysts such as hydroxy pyridines or aminocarboxylic acids to accelerate the intercondensation of aromatic bis(ether anhydride) and organic diamine or prepolymer thereof under solution or melt polymerization conditions.
    Type: Grant
    Filed: September 19, 1980
    Date of Patent: May 18, 1982
    Assignee: General Electric Company
    Inventors: Dwain M. White, David G. Keyes
  • Quaternary Group VA salt catalyzed method for making polyetherimide
    Patent number: 4324885
    Abstract: A method is provided for making polyetherimides, based on the use of certain quaternary Group VA salts, for example tetra-alkylammonium halides, to accelerate the intercondensation of aromatic bis(ether anhydride) and organic diamine under solution or melt polymerization conditions. The resulting polyetherimides are high performance, injection moldable thermoplastics.
    Type: Grant
    Filed: September 25, 1980
    Date of Patent: April 13, 1982
    Assignee: General Electric Company
    Inventors: Dwain M. White, David G. Keyes
  • Organic amine catalyzed method for making polyetherimide
    Patent number: 4324884
    Abstract: A method is provided for making polyetherimides, based on the use of certain organic diamine catalysts, for example, 4-dimethylaminopyridine and secondary or tertiary aliphatic diamines, to accelerate the intercondensation of aromatic bis(ether anhydride) and organic diamine under solution or melt polymerization conditions. The resulting polyetherimides are high performance injection moldable thermoplastics.
    Type: Grant
    Filed: September 25, 1980
    Date of Patent: April 13, 1982
    Assignee: General Electric Company
    Inventors: Dwain M. White, David G. Keyes
  • Method for making polyetherimide using a phenolic or carboxylic acid catalyst
    Patent number: 4324883
    Abstract: A method is provided for making polyetherimide based on the use of an organic carboxylic acid or phenolic catalyst which is added in a controlled manner to a solution polymerization mixture of an organic dianhydride and organic diamine. An enhancement of the rate of polymerization is achieved if the catalyst addition is effected after at least a predetermined amount of water of reaction is separated from the mixture.
    Type: Grant
    Filed: September 19, 1980
    Date of Patent: April 13, 1982
    Assignee: General Electric Company
    Inventors: Dwain M. White, David G. Keyes