Patents by Inventor Chester A. Thayer

Chester A. Thayer 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 making improved metal stencil screens for screen printing
    Patent number: 5573815
    Abstract: Polymeric ledges on a metal stencil screen are made using a polymeric layer which is partially removed by a developer solution.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: November 12, 1996
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Allan Cairncross, Chester A. Thayer, II
  • Process for making improved metal stencil screens for screen printing
    Patent number: 5447757
    Abstract: Polymeric ledges on a metal stencil screen are made using a polymeric layer which is partially removed by a developer solution.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: September 5, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Allan Cairncross, Chester A. Thayer, II
  • Process for the synthesis of lactide or glycolide from lactic acid or glycolide acid oligomers
    Patent number: 5374743
    Abstract: A process for preparing lactide or glycolide from a lactic acid oligomer or glycolic acid oligomer is disclosed where the molecular weight of the synthesis reactor residue is controlled to no more than 1.2 times that in the feed. The process is carried out at 130.degree. to 280.degree. C. and preferably 180.degree. to 210.degree. C. using from 1 to 6 weight percent catalyst in the oligomer feed to the synthesis reactor. The catalysts are tin or tin compounds, yttrium or rare earth metal compounds, or antimony compounds which are known as alphahydroxycarboxylic acid cyclic dimerization or polymerization catalysts.
    Type: Grant
    Filed: September 30, 1993
    Date of Patent: December 20, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Chester A. Thayer, Harold E. Bellis
  • Process for making metal ledge on stencil screen
    Patent number: 5322763
    Abstract: A process for making a metal ledge on one side of a metal screen involves exposing through the stencil screen a photoresist layer, removing unexposed photoresist areas, plating the metal stencil screen where the unexposed photoresist has been removed and removing the exposed photoresist.
    Type: Grant
    Filed: May 6, 1992
    Date of Patent: June 21, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Allan Cairncross, Chester A. Thayer, II
  • Process for defined etching of substrates
    Patent number: 5043244
    Abstract: A process is described for defined etching of holes using a sliver mask formed by silver diffusion transfer imaging.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: August 27, 1991
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Allan Cairncross, Chester A. Thayer, II