Patents by Inventor Robert F. Drury

Robert F. Drury 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).

  • Stripping method for removing resist from a printed circuit board
    Patent number: 5145717
    Abstract: A stripping method is provided to remove processed photoresist images from printed circuit substrates without damage to underlying high density circuitry. A solid particulate blast process is used to remove the resist images wherein the polymeric particles having a Mho hardness in the range from 2.0 to 4.0 are used as the blast media.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: September 8, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert F. Drury
  • Synthesis of 2,5-dihydrofuran
    Patent number: 4231941
    Abstract: Improved process for preparing 2,5-dihydrofuran by the dehydration of 1-butene-3,4-diol in the presence of a soluble mercury salt as catalyst in a dissociating solvent at a neutral or acidic pH at an elevated temperature, the improvement characterized in that the dehydration is carried out at a pH of 4 to 7 at 80.degree.-120.degree. C. in the presence of solid mercuric oxide.
    Type: Grant
    Filed: June 25, 1979
    Date of Patent: November 4, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert F. Drury