Patents by Inventor Willem F. Verhelst

Willem F. Verhelst 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: 5369197
    Abstract: Aqueous emulsions of a polymerization initiator are used for suspension (co)polymerization reactions. The aqueous emulsions contain: (a) an organic peroxide which is liquid at -5.degree. C.; (b) an aliphatic monohydric alcohol having 1-4 carbon atoms and/or aliphatic glycol having 2-4 carbon atoms; (c) a surfactant and/or a protective colloid; and (d) water. The emulsions may be transported while in a liquid state at a temperature of -10.degree. C. to -25.degree. C. with minimal decrease in active oxygen content.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: November 29, 1994
    Assignee: Akzo N.V.
    Inventors: Reinder Torenbeek, Willem F. Verhelst
  • Patent number: 5260390
    Abstract: This disclosure relates to aqueous peroxide emulsions and the use thereof in suspension (co)polymerization reactions. In particular, the aqueous peroxide emulsions comprise: a) 20-60% by weight of an organic peroxide which is liquid at -5.degree. C.; b) 2-20% by weight of an aliphatic monohydric alcohol having 1-4 carbon atoms and/or aliphatic glycol having 2-4 carbon atoms; c) a surfactant and/or a protective colloid; and d) water. The emulsions of the present disclosure may be transported while in a liquid state at a temperature of -10.degree. C. to -25.degree. C. with minimal decrease in active oxygen content.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: November 9, 1993
    Assignee: Akzo N.V.
    Inventors: Reinder Torenbeek, Willem F. Verhelst
  • Patent number: 4950422
    Abstract: This disclosure relates to aqueous peroxide emulsions and the use thereof in suspension (co)polymerization reactions. In particular, the aqueous peroxide emulsions comprise: (a) 20-60% by weight of an organic peroxide which is liquid at -5.degree. C.; (b) 2-20% by weight of an aliphatic monohydric alcohol having 1-14 carbon atoms and/or aliphatic glycol having 2-4 carbon atoms; (c) a surfactant and/or a protective colloid; and (d) water. The emulsions of the present disclosure may be transported while in a liquid state at a temperature of -10.degree. C. to -25.degree. C. with minimal decrease in active oxygen content.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: August 21, 1990
    Assignee: Akzona Incorporated
    Inventors: Reinder Torenbeek, Willem F. Verhelst
  • Patent number: 4391962
    Abstract: An improved process for the suspension polymerization of vinyl chloride in the presence of a radical initiator and at least two suspension stabilizers is disclosed. The improvement comprises performing the polymerization in the presence of at least one primary stabilizer selected from the group consisting of water-soluble partially hydrolyzed polyvinyl acetates and methyl hydroxypropyl cellulose and at least one secondary stabilizer selected from the group consisting of N-alkyl gluconamides wherein the alkyl group contains from about 16 to about 20 carbon atoms.
    Type: Grant
    Filed: November 20, 1980
    Date of Patent: July 5, 1983
    Assignee: Akzona Incorporated
    Inventors: Petrus H. M. Schreurs, Willem F. Verhelst
  • Patent number: 4374938
    Abstract: This disclosure relates to a process for the degradation of polymers in the presence of a free radical initiator. In particular this disclosure relates to a process for the degradation of polymers employing a free radical initiator selected from a class of hydroximic acid derivatives.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: February 22, 1983
    Assignee: Akzona Incorporated
    Inventors: Willem F. Verhelst, Ulfert E. Wiersum