Patents by Inventor Bertold Nathal

Bertold Nathal 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 the preparation of partially protected phenolic resins
    Patent number: 5663038
    Abstract: A process for the preparation of phenolic resins having acid-labile acetal or ketal protecting groups by reacting a phenolic resin with an enol ether in the presence of an acidic catalyst and subsequently treating the reaction mixture with a basic anion exchanger gives heat-resistant polymers which, in combination with acid photogenerators, produce radiation-sensitive compositions of high processing stability with a greatly improved shelf life.
    Type: Grant
    Filed: December 14, 1995
    Date of Patent: September 2, 1997
    Assignee: OCG Microelectronic Materials, Inc.
    Inventors: Carl-Lorenz Mertesdorf, Bertold Nathal, Hans-Jorg Kirner