Patents by Inventor Howard J. Klopfer

Howard J. Klopfer 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 with high thermal stability and solvent resistance and precursors therefor
    Patent number: 4565858
    Abstract: Polyetherimides and their polyamic acid precursors are derived from bisphenol A dianhydride, or a mixture thereof with pyromellitic dianhydride, and bis(4-aminophenyl) sulfone or a mixture thereof with m-phenylenediamine and/or p-phenylenediamine. The polyetherimides are characterized by high thermal stability and solvent resistance.
    Type: Grant
    Filed: October 26, 1984
    Date of Patent: January 21, 1986
    Assignee: General Electric Company
    Inventor: Howard J. Klopfer
  • Process for preparation of hydroxyaryldialkylcarbinols
    Patent number: 4460800
    Abstract: The preparation of hydroxyaryldialkylcarbinols by the reaction of hydroxyaryl alkyl ketones or alkyl hydroxyarenecarboxylates with Grignard reagents in a mixed ether-aromatic hydrocarbon solvent is frequently difficult on a large-scale basis because of formation of a voluminous precipitate of mixed magnesium salt. In an improvement in this process, a solution of the ketone or ester in an ether is added to the solution of the Grignard reagent.
    Type: Grant
    Filed: February 22, 1983
    Date of Patent: July 17, 1984
    Assignee: General Electric Company
    Inventors: Charles M. Orlando, Howard J. Klopfer
  • Process for preparation of asymmetrical bisphenols
    Patent number: 4460798
    Abstract: Asymmetrical bisphenols such as 2-(3-hydroxyphenyl)-2-(4-hydroxyphenyl)propane are prepared by an improved process wherein a hydroxyphenyldialkylcarbinol is reacted with a phenol in the presence of a hydrogen halide catalyst. According to the improved process, the carbinol is added to a mixture of the phenol and hydrogen halide under conditions maintaining a low carbinol concentration in the reaction mixture. This low concentration is preferably maintained by adding the carbinol in the form of a solution in a portion of the phenol.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: July 17, 1984
    Assignee: General Electric Company
    Inventors: Howard J. Klopfer, Charles M. Orlando
  • Method for making polyetherimides using carboxylic acid salts of alkali metals or zinc as catalysts
    Patent number: 4293683
    Abstract: A method is provided for enhancing the rate of formation of polyetherimides under melt or solution polymerization conditions by using either an alkali metal carboxylic acid salt, or a zinc carboxylic acid salt as a catalyst. The aforementioned catalysts are employed in a polymerization mixture of aromatic bis(ether anhydride) and an organic diamine.
    Type: Grant
    Filed: July 11, 1980
    Date of Patent: October 6, 1981
    Assignee: General Electric Company
    Inventors: Tohru Takekoshi, Howard J. Klopfer
  • Preparation of 1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane
    Patent number: 4128731
    Abstract: The compound 1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane can be prepared by effecting reaction between phenol and chloral in a solvent medium comprising aqueous sulfuric acid of a concentration of from 75 to 88%.
    Type: Grant
    Filed: June 6, 1977
    Date of Patent: December 5, 1978
    Assignee: General Electric Company
    Inventors: Howard J. Klopfer, John R. Campbell
  • Process for preparing phenyl trichloro-ethanes
    Patent number: 4105857
    Abstract: Diphenyl trichloro-ethanes can be prepared by effecting reaction between a phenol or anisole (methoxybenzene) with chloral in a solvent medium comprising sulfuric acid and a liquid aliphatic chlorohydrocarbon containing from 1 to 2 carbon atoms.
    Type: Grant
    Filed: April 4, 1977
    Date of Patent: August 8, 1978
    Assignee: General Electric Company
    Inventors: John R. Campbell, Howard J. Klopfer
  • Purification of crude 9,9-bis-(4-hydroxyphenyl)-fluorene
    Patent number: 4049721
    Abstract: Certain impurities found in 9,9-bis(4-hydroxyphenyl)-fluorene are removed by treatment of the latter with a methanol-water mixture and thereafter isolating the purified fluorene.
    Type: Grant
    Filed: September 7, 1976
    Date of Patent: September 20, 1977
    Assignee: General Electric Company
    Inventors: John E. Corn, Jr., Howard J. Klopfer
  • Method for making polyetherimides using a sodium chloride or ferric sulfate catalyst
    Patent number: 3998840
    Abstract: A method is provided for enhancing the rate of formation of polyetherimides by using either a sodium chloride catalyst, or ferric sulfate catalyst in a mixture of an aromatic bis(ether anhydride) and an organic diamine under melt polymerization conditions.
    Type: Grant
    Filed: April 16, 1976
    Date of Patent: December 21, 1976
    Assignee: General Electric Company
    Inventors: Frank J. Williams, III, Howard J. Klopfer