Patents by Inventor Howard M. Relles

Howard M. Relles 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).

  • Polyetherimides prepared by self-condensation of hydroxyaryl phthalimide salts
    Patent number: 4297474
    Abstract: Polyetherimides are provided which are based on the self-condensation in a dipolar aprotic solvent of a hydroxyaryl phthalimide salt having a nuclear bound leaving radical on the phthalimide ring. The polyetherimides are injection-moldable high performance thermoplastics.
    Type: Grant
    Filed: February 29, 1980
    Date of Patent: October 27, 1981
    Assignee: General Electric Company
    Inventors: Frank J. Williams, III, Howard M. Relles
  • Liquid extraction method for recovering aromatic bisimides
    Patent number: 4247464
    Abstract: A liquid extraction method is provided for recovering aromatic bisimides from an organic solvent aromatic bisimide reaction mixture having a variety of reaction by-products. An organic solvent solution of the bisimide reaction mixture is extracted with water and/or an aqueous alkali metal hydroxide to effect removal of such reaction by-products, and provide an organic solvent phase of the aromatic bisimide which can be obtained in substantially pure form upon removal of the organic solvent.
    Type: Grant
    Filed: October 1, 1979
    Date of Patent: January 27, 1981
    Assignee: General Electric Company
    Inventors: Howard M. Relles, Frank J. Williams, III
  • Aromatic polyformal-polycarbonate block polymers and method for making same
    Patent number: 4210731
    Abstract: There are provided aromatic polyformal-polycarbonate block polymers and method for making such materials. The polyformal-polycarbonate block polymers can be made by phosgenating a mixture of a bisphenol and oligomeric aromatic polyformal having terminal phenolic groups. The aromatic block polymers are high performance thermoplastics having improved hydrolytic stability compared to aromatic polycarbonates and improved heat distortion temperature compared to conventional aromatic polyformal.
    Type: Grant
    Filed: September 18, 1978
    Date of Patent: July 1, 1980
    Assignee: General Electric Company
    Inventors: Howard M. Relles, Donald S. Johnson
  • Preparation of aromatic bisimides
    Patent number: 4054577
    Abstract: Aromatic bisimides can be prepared by effecting reaction under anhydrous conditions between a 3- or 4-nitro-N-substituted phthalimide with an aromatic dihydroxy compound in the presence of a certain class of dipolar aprotic compounds as solvent and solid potassium carbonate and in the further presence of a particulate zeolite adsorbent.
    Type: Grant
    Filed: May 6, 1976
    Date of Patent: October 18, 1977
    Assignee: General Electric Company
    Inventors: Howard M. Relles, Donald S. Johnson
  • Preparation of aromatic tetracarboxylic acids
    Patent number: 4020069
    Abstract: Aromatic tetracarboxylic acids can be prepared by effecting reaction between a 4-nitro-N-alkylphthalimide with an aromatic dihydroxy compound in the presence of potassium carbonate as a catalyst and using dimethyl sulfoxide as a solvent.
    Type: Grant
    Filed: July 25, 1975
    Date of Patent: April 26, 1977
    Assignee: General Electric Company
    Inventors: Donald S. Johnson, Howard M. Relles