Patents by Inventor Howard Stephen Friedman

Howard Stephen Friedman 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).

  • Benzoquinoneimines as vinyl aromatic polymerization inhibitors
    Patent number: 6222080
    Abstract: This invention relates to a vinyl aromatic, especially styrene, polymerization inhibitor system comprising an N-phenyl-1,4-benzoquinoneimine compound and optionally an aryl-substituted phenylenediamine.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: April 24, 2001
    Assignee: Uniroyal Chemical Company, Inc.
    Inventors: Howard Stephen Friedman, Paul Edwin Stott
  • Benzoquinoneimines as vinyl aromatic polymerization inhibitors
    Patent number: 6039895
    Abstract: This invention relates to a vinyl aromatic, especially styrene, polymerization inhibitor system comprising an N-phenyl-1,4-benzoquinoneimine compound and optionally an aryl-substituted phenylenediamine.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: March 21, 2000
    Inventors: Howard Stephen Friedman, Paul Edwin Stott
  • Composition for inhibiting the polymerization of aromatic vinyl monomers
    Patent number: 5659095
    Abstract: A polymerization inhibitor composition for inhibiting the polymerization of aromatic vinyl monomers at elevated temperatures comprising:(a) a benzofuroxan derivative of the formula ##STR1## wherein R is C.sub.1 -C.sub.4 alkyl or alkoxy; R.sup.1 is a nitro group; and m and n are each independently 0, 1, or 2; and(b) a solvent selected from the group consisting of toluene, xylene, ethylbenzene, vinyltoluene, divinylbenzene, alpha-methylstyrene, and a C.sub.12 -C.sub.18 hydrocarbon,and methods for inhibiting the polymerization of aromatic vinyl monomers at elevated temperatures using this composition.
    Type: Grant
    Filed: March 13, 1996
    Date of Patent: August 19, 1997
    Assignee: Uniroyal Chemical Company, Inc.
    Inventors: Howard Stephen Friedman, Gerald John Abruscato, John Matthew DeMassa, Anthony Vincent Gentile, Anthony Vincent Grossi