Patents by Inventor Leonie Arina Stigter

Leonie Arina Stigter 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).

  • Modification of (co) polymers with cyclic ketone peroxides
    Patent number: 5932660
    Abstract: A process for the modification of (co) polymers employing an organic peroxide comprising the step of contacting a (co) polymer with organic peroxide under conditions whereby at least some of the said organic peroxide is decomposed, is disclosed. The process is characterized in that at least 20% of the total active oxygen content of said organic peroxide is attributable to one or more cyclic ketone peroxides. In a second aspect, the invention relates to the use of an organic peroxide composition wherein at least 20% of the total active oxygen content is contributed by one or more cyclic ketone peroxide(s) modify (co) polymers. It has been found that these cyclic ketone peroxides are extremely efficient in (co) polymer modification processes.
    Type: Grant
    Filed: March 13, 1997
    Date of Patent: August 3, 1999
    Assignee: Akzo Nobel nv
    Inventors: John Meijer, Andreas Herman Hogt, Gerrit Bekendam, Leonie Arina Stigter
  • Cyclic ketone peroxides as polymer initiators
    Patent number: 5907022
    Abstract: A process for the preparation of (co)polymers employing a peroxide composition comprising at least one organic peroxide wherein at least 20% of the total active oxygen content of said organic peroxide is attributable to one or more cyclic ketone peroxides represented by the following formulas I-III: ##STR1## These cyclic ketone peroxides are highly efficient as polymerization initiators.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: May 25, 1999
    Assignee: Akzo Nobel nv
    Inventors: Leonie Arina Stigter, John Meijer, Andreas Petrus van Swieten