Patents by Inventor Thomas Hassall, Jr.

Thomas Hassall, Jr. 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).

  • Dry blending process for the quaternization of polyvinyl alcohol
    Patent number: 4775715
    Abstract: Cationic polyvinyl alcohol is prepared by blending polyvinyl alcohol under high shear conditions, at 0.degree.-100.degree. C., with a small amount of water, a small excess of base, and a quaternizing agent containing a halohydrin radical and a quaternary ammonium group. The quaternization proceeds with acceptable conversions of about 35 to well over 50%. The quaternized polyvinyl alcohol has many applications, including use as a flocculating agent, as a stabilizing colloid, and in adhesive formulations.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: October 4, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Aleksander Beresniewicz, Thomas Hassall, Jr.
  • Polyvinyl alcohol dust suppression by admixing polyglycol
    Patent number: 4389506
    Abstract: A process for the preparation of a substantially dust-free PVA powder comprising contacting the PVA with about 0.5 percent to 4.0 percent polyglycol, preferably about 0.5 percent to 2.0 percent polyglycol, based on the weight of the PVA, and the product therefrom.
    Type: Grant
    Filed: June 29, 1981
    Date of Patent: June 21, 1983
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Thomas Hassall, Jr.