Patents by Inventor Duncan M. A. Grieve

Duncan M. A. Grieve 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: 5492803
    Abstract: A photothermographic element comprising a support bearing at least one heat-developable, photosensitive, image-forming photothermographic emulsion layer comprising:(a) a photosensitive silver halide;(b) a non-photosensitive, reducible source of silver;(c) a reducing agent for the non-photosensitive reducible silver source; and(d) a binder;wherein the reducing agent is a hydrazide redox-dye-releasing compound of the general formulae: ##STR1## wherein: D represents the chromophore of a thermally mobile dye; X represents a single bond or a divalent linking group; R.sup.1 and R.sup.2 independently represent an organic group; and n.gtoreq.1.
    Type: Grant
    Filed: January 6, 1995
    Date of Patent: February 20, 1996
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Kevin D. Landgrebe, Doreen C. Lynch, Sharon M. Simpson, Justine A. Mooney, Andrew W. Mott, Duncan M. A. Grieve, John H. A. Stibbard, Robert J. D. Nairne, Stephen S. C. Poon, David C. Bays
  • Patent number: 4950577
    Abstract: Presensitized sheets for color proofing comprising a removable carrier sheet bearing a photosensitive medium sensitive to radiation within the wavelength band 325 to 700 nm and comprising photohardenable, photoadherent, photoinsolubilisable or photosolubilisable material, the sheet including a removable antihalation layer which is removed either when stripping the carrier sheet or during subsequent processing. The antihalation dyes may be positioned within a transparent carrier sheet, in a layer on the carrier sheet opposite to the photosensitive medium or in a layer positioned between the carrier sheet and light-sensitive medium.
    Type: Grant
    Filed: May 23, 1985
    Date of Patent: August 21, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Duncan M. A. Grieve, Ronald W. Burrows, John Souter
  • Patent number: 4923792
    Abstract: A photothermographic element comprising:(A) a coating comprising a support bearing a photothermographic medium, the medium comprising a light sensitive silver halide in reactive association with a silver salt of an organic acid and a color generating reducing agent which is a leuco compound which is oxidizable by silver ions into a colored dye of the general formula: ##STR1## in which: n=0, 1 or 2,R.sup.1 represents H, CN, lower alkyl of 1 to 5 carbon atoms, aryl or COOR.sup.6 in which R.sup.6 is lower alkyl of 1 to 5 carbon atoms or aryl,R.sup.2 and R.sup.3 independently represent CN, NO.sub.2, COOR.sup.6, SO.sub.2 R.sup.6, CONHR.sup.6 in which R.sup.6 is as defined above or R.sup.2 and R.sup.3 together represent the necessary atoms to form a 5- or 6-membered carbocyclic or heterocyclic ring having ring atoms selected from C, N, O and S atoms, whch carbocyclic or heterocyclic rings possess at least one conjugated electron withdrawing substituent,R.sup.4 and R.sup.
    Type: Grant
    Filed: June 20, 1989
    Date of Patent: May 8, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Duncan M. A. Grieve, Stephen S. C. Poon, Tran V. Thien, Kumars Sakizadeh, David C. Weigel
  • Patent number: 4883747
    Abstract: A photothermographic element comprising a support bearing a photothermographic medium, the medium comprising a light sensitive silver halide in reactive association with a silver salt of an organic acid and a color generating reducing agent which is a leuco compound which is oxidisable by silver ions into a colored dye of the general formula: ##STR1## in which: n=0, 1 or 2,R.sup.1 represents H, CN, lower alkyl of 1 to 5 carbon atoms, aryl or COOR.sup.6 in which R.sup.6 is lower alkyl of 1 to 5 carbon atoms or aryl,R.sup.2 and R.sup.3 independently represent CN, NO.sub.2, COOR.sup.6, SO.sub.2 R.sup.6, CONHR.sup.6 in which R.sup.6 is as defined above or R.sup.2 and R.sup.3 together represent the necessary atoms to form a 5- or 6-membered carbocyclic or heterocyclic ring having ring atoms selected from C, N, O and S atoms, which carbocyclic or heterocyclic rings possess at least one conjugated electron withdrawing substituent,R.sup.4 and R.sup.
    Type: Grant
    Filed: May 31, 1988
    Date of Patent: November 28, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Duncan M. A. Grieve, Stephen S. C. Poon, Tran V. Thien, Kumars Sakizadeh, David C. Weigel