Patents by Inventor Robert P. Held

Robert P. Held 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).

  • Patent number: 4461823
    Abstract: A surface having tacky images which comprise toner-receptive and background areas can be color developed by applying to the toner-receptive areas a prolonged tack toner, heating the toned image to a temperature sufficient to make the toner tacky, reducing the temperature of the tackified toned image below the tackifying temperature, the toner remaining tacky, and repeating the toner application, heating and cooling steps at least once. The prolonged tack toned image can be used in single or multiple transfers to an image receptor. The transferred image can also be toned with prolonged tack toner to generate an image of higher optical density.
    Type: Grant
    Filed: September 20, 1982
    Date of Patent: July 24, 1984
    Assignee: E. I. Du Pont De Nemours and Company
    Inventor: Robert P. Held
  • Patent number: 4416968
    Abstract: A dry-printing process which employs a photopolymer film and two toners, one for generating a master and a second for image transfer.
    Type: Grant
    Filed: September 9, 1982
    Date of Patent: November 22, 1983
    Assignee: E. I. Du Pont de Nemours & Co.
    Inventor: Robert P. Held
  • Patent number: 4264692
    Abstract: Photopolymerized elements having addition polymerized and unpolymerized image areas comprise a support bearing a layer having hydrophilic or oleophilic polymerized image areas and unpolymerized areas of opposite character, at least one of the image areas having absorbed therein a dye of like character. The dye absorbed photopolymerized elements are prepared after imagewise exposure by leaching out ethylenically unsaturated compound in the unexposed areas and absorbing a dye of like character and solvent carrier for the dye into at least one of the image areas. The dye and carrier mixture are capable of swelling the image areas wherein the dye is absorbed. The absorbed dye is not capable of being transferred from the element. Positive and negative working color copies are produced useful in overlay or projection applications.
    Type: Grant
    Filed: May 25, 1979
    Date of Patent: April 28, 1981
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert P. Held
  • Patent number: 4198236
    Abstract: A lithographic printing plate is prepared from a layer of a photopolymerizable composition comprising an oleophilic macromolecular organic binder and a leachable hydrophilic ethylenically unsaturated compound by exposing the layer and then leaching the compound from the unexposed areas by treating with a suitable developing solvent, preferably water, producing an oleophilic surface. A similar plate may be prepared from a composition containing a hydrophilic binder and oleophilic leachable compound by imagewise exposure and solvent leaching producing an oleophilic surface in exposed areas and a hydrophilic surface in unexposed areas.
    Type: Grant
    Filed: November 30, 1978
    Date of Patent: April 15, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert P. Held
  • Patent number: 4147549
    Abstract: A lithographic printing plate is prepared from a layer of a photopolymerizable composition comprising an oleophilic macromolecular organic binder and a leachable hydrophilic ethylenically unsaturated compound by e posing the layer and then leaching the compound from the unexposed areas by treating with a suitable developing solvent, preferably water, producing an oleophilic surface. A similar plate may be prepared from a composition containing a hydrophilic binder and oleophilic leachable compound by imagewise exposure and solvent leaching producing an oleophilic surface in exposed areas and a hydrophilic surface in unexposed areas.
    Type: Grant
    Filed: June 22, 1977
    Date of Patent: April 3, 1979
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Robert P. Held