Patents by Inventor David S. Pietrewicz

David S. Pietrewicz 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: 5264474
    Abstract: Described are thermoplastic or thermoset polymer and resin compositions (e.g., nylon, polyvinylchloride, phenolics, etc.) containing a bis-sulfonamide or polyhaloaromatic monosulfonamide in quantity sufficient to plasticize the resins and polymers. The polyhaloaromatic monosulfonamide contains (a) from 7 to 30 carbon atoms, (b) from 2 to 12 chlorine and/or bromine atoms, (c) one nitrogen atom, (d) an aromatic group, bonded to the sulfur atom, in which at least two chlorine or at least two bromine atoms or at least one chlorine atom and at least one bromine atom are directly bonded to the aromatic ring system, and (e) one or two aliphatic, cycloaliphatic, or aromatic organic groups bonded to the nitrogen atom, one such organic group, when an aromatic group, optionally being substituted by one or more bromine and/or chlorine atoms. The bis-sulfonamide contains at least two aromatic rings and from 14 to 30 carbon atoms in the molecule.
    Type: Grant
    Filed: September 18, 1991
    Date of Patent: November 23, 1993
    Assignee: MTM Americas Inc.
    Inventors: Robert A. Schleifstein, David S. Pietrewicz
  • Patent number: 4957957
    Abstract: Described are thermoplastic polymer compositions (e.g., nylon) containing a polyhaloaromatic sulfonamide in quantity sufficient to improve the melt flow properties of the polymer. Such sulfonamides contain (a) from 7 to 30 carbon atoms, (b) from 2 to 12 chlorine and/or bromine atoms, (c) one nitrogen atom, (d) an aromatic group, bonded to the sulfur atom, in which at least two chlorine or at least two bromine atoms or at least one chlorine atom and at least one bromine atom are directly bonded to the aromatic ring system, and (e) one or two aliphatic, cycloaliphatic, or aromatic organic groups bonded to the nitrogen atom, one such organic group, when an aromatic group, optionally being substituted by one or more bromine and/or chlorine atoms. These sulfonamides are of advantage in that they have relatively low volatilities and good thermal stability at polymer processing temperatures and serve as flame retardants therein.
    Type: Grant
    Filed: June 1, 1989
    Date of Patent: September 18, 1990
    Assignee: Ethyl Corporation
    Inventors: Robert A. Schleifstein, David S. Pietrewicz