Patents by Inventor Chandra Sreekumar

Chandra Sreekumar 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: 4927727
    Abstract: Disclosed is an improved method of making a hard copy in a process where a latent electrostatic image on an image-bearing substrate is developed by applying to the image a dry thermoplastic toner which comprises a binder polymer, and the developed image is transferred to the surface of a receiver by contacting the developed image on the substrate with the surface, then removing the surface from the substrate. The improvement comprises developing the latent electrostatic image with a toner having a particle size less than 8 micrometers, heating the surface before it contacts the developed image to a temperature such that the surface heats the toner particles when it contacts the developed image to a temperature between 10.degree. C. above the T.sub.g of the toner binder and 20.degree. C. below the T.sub.
    Type: Grant
    Filed: August 9, 1988
    Date of Patent: May 22, 1990
    Assignee: Eastman Kodak Company
    Inventors: Donald S. Rimai, Chandra Sreekumar
  • Patent number: 4869992
    Abstract: Disclosed is a method of making particulates. A solution is formed of a solvent. a first polymer having an intrinsic viscosity of at least 0.5, and a second polymer having an intrinsic viscosity of less than 0.5. The solution is atomized with a gas to form droplets of the solution suspended in the gas. The evaporation of the solvent leaves the particles suspended in the gas and the particles are collected to form the toner. Also disclosed is toner made by this method, and a method of making an electrographic printing plate by developing an electrostatic image with the toner, transferring the developed image to a substrate, and fixing the transferred image on the substrate. Also disclosed is an electrographic printing plate made according to that method.
    Type: Grant
    Filed: June 28, 1988
    Date of Patent: September 26, 1989
    Assignee: Eastman Kodak Company
    Inventor: Chandra Sreekumar
  • Patent number: 4833060
    Abstract: Toner and/or carrier particles are prepared by dissolving a polymer in a solvent which is immiscible with water forming a suspension of small droplets of the polymer and solvent in water containing a promoter and silica particles, removing the solvent from the droplets and separating the solidified particles from the water.
    Type: Grant
    Filed: March 21, 1988
    Date of Patent: May 23, 1989
    Assignee: Eastman Kodak Company
    Inventors: Mridula Nair, Zona R. Pierce, Chandra Sreekumar
  • Patent number: 4681828
    Abstract: A method of forming an image is disclosed in which chemically active toner particles are used to trigger image amplification chemistry after their attraction to an electrostatic charge pattern.The method of forming an image comprises applying electrographic toner particles to a charge pattern on a support followed by a chemical amplification processing step comprising heating the toner image in the presence of an image-receiving element comprising:(a) a cobalt(III) complex capable of releasing an amine on processing, and(b) an amplifier which, on reaction with an amine:(i) forms a dye or dye precursor, or(ii) reduces the cobalt(III) complex, resulting in the release of additional amine,said toner comprising an activator which, under the conditions of processing releases an amine either directly or indirectly.
    Type: Grant
    Filed: September 2, 1986
    Date of Patent: July 21, 1987
    Assignee: Eastman Kodak Company
    Inventors: Peter S. Alexandrovich, Joseph W. Manthey, John W. May, Chandra Sreekumar
  • Patent number: 4547449
    Abstract: Liquid electrographic developers are disclosed comprising an electrically insulating liquid carrier, toner, a charge-control agent and a charging agent. The charge-control agent is a carrier-soluble, addition copolymer of a quaternary ammonium salt monomer, a monomer having --COOH, --SO.sub.3 H or --PO.sub.3 HR acidic function wherein R is hydrogen or alkyl, and a solubilizing monomer. The charging agent is a carrier-soluble, addition polar copolymer. The disclosed developers exhibit improved replenishability as evidenced by reduced buildup of charge in the developers during the course of use and repeated replenishment.
    Type: Grant
    Filed: January 16, 1985
    Date of Patent: October 15, 1985
    Assignee: Eastman Kodak Company
    Inventors: Peter S. Alexandrovich, Louis J. Sorriero, Chandra Sreekumar