Patents by Inventor Albert H. Levesque

Albert H. Levesque 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: 5811584
    Abstract: Process for the production of TMEDA in high yield by reducing 2,3-dimethyl-2,3-dinitrobutane with hydrogen in the presence of a chromium promoted Raney cobalt catalyst. A solution of 2,3-dimethyl-2,3-dinitrobutane in a suitable solvent is fed to a reactor while avoiding the accumulation of 2,3-dimethyl-2,3-dinitrobutane in the reaction medium, such as by feeding it at a rate no greater than its rate of reaction with hydrogen. In a preferred embodiment, the resulting TMEDA is recovered by converting it to an amine salt by sparging carbon dioxide through the solution.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: September 22, 1998
    Assignee: Hampshire Chemical Corp.
    Inventors: Gerald J. O'Neill, Albert H. Levesque, Robert J. Bulka
  • Patent number: 5616772
    Abstract: A method of stabilizing nitriles, and in particular iminodiacetonitrile (IDAN), ethylendiamine-triacetonitrile (EDTN), and especially nitrilotriacetonitrile (NTAN). The present invention also encompasses the resulting stabilized nitrile. The method of the present invention comprises contacting the nitrile with a mixture of silica and alumina, zeolites or glass.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 1, 1997
    Assignee: Hampshire Chemical Corp.
    Inventors: Gerald J. O'Neill, Albert H. Levesque
  • Patent number: 5097072
    Abstract: Polyamines are prepared via the batchwise hydrogenation of polynitriles by the gradual addition of the polynitrile into a fed-batch reactor which contains chromium promoted Raney.RTM. cobalt catalyst. The hydrogenation optionally is conducted in the presence of anhydrous ammonia. The polyamine product having amino groups which corresponds to the nitrile of the polynitrile is economically obtained in high selectivity and yield as the dominant product.
    Type: Grant
    Filed: March 21, 1991
    Date of Patent: March 17, 1992
    Assignee: W.R. Grace & Co.-Conn.
    Inventors: Gerald J. O'Neill, Albert H. Levesque