Patents by Inventor Guenter Graeff

Guenter Graeff 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).

  • Process for synthesis of Di(meth)acrylic acid esters
    Patent number: 6639099
    Abstract: A process for the synthesis and recovery of di(meth)acrylic acid esters at a high degree of purity. Di(meth)acrylic acid esters are produced by transesterfication of (meth)acrylic acid esters of C1 to C4 alcohols with 1,n-diols (where n≧3) in the presence of a zirconium catalyst that comprises a chelate of zirconium with a 1,3-dicarbonyl compound. These catalysts can be readily separated or removed from the reaction mixture by precipitation with phosphoric acid, thus providing a convenient and inexpensive method of producing a di(meth)acrylic acid ester with a reduced level of zirconium.
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: October 28, 2003
    Assignee: Roehm GmbH & Co. KG
    Inventors: Joachim Knebel, Joachim Carl, Guenter Graeff, Andrea Wittkowski