Patents by Inventor Frans Henri Claes

Frans Henri Claes 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).

  • Dispersing polymeric particles in aqueous medium for coating silver halide emulsion layers
    Patent number: 4022622
    Abstract: Polymeric particles are homogeneously dispersed in aqueous medium by a process which comprises dissolving a water-insoluble film-forming polymer in a water-insoluble, ethylenically unsaturated monomer which is liquid at room temperature. The solution formed is dispersed by stirring in an aqueous solution of a hydrophilic colloid and of a dispersing agent, stirring being continued until a stable dispersing of polymer-in-monomer solution droplets having a diameter between 1 and 10 microns, preferably between 1 and 6 micron, in said aqueous solution is obtained. While continuously stirring the dispersion in the presence of a free-radical forming polymerization initiator, the dispersion is heated at the decomposition temperature of said polymerization initiator to effect polymerization of the water-insoluble, liquid monomer and to form an aqueous dispersion of solvent-free polymer particles.
    Type: Grant
    Filed: March 1, 1976
    Date of Patent: May 10, 1977
    Assignee: AGFA-GEVAERT N.V.
    Inventors: Daniel Maurice Timmerman, Victor Jan Thijs, Walter Frans De Winter, Frans Henri Claes, Hubert Vandenabeele
  • Method of preparing photographic silver halide emulsions
    Patent number: 3957490
    Abstract: Silver halide emulsions are prepared by silver halide precipitation in the presence of a reducing agent, physical ripening and, if desired, chemical ripening wherein subsequent to the addition of reducing agent and before the grains have reached their final size an oxidizing agent is added to the emulsion. By means of the reducing and oxidizing agents, the gradation and photosensitivity characteristics of the emulsion can be controlled at will.
    Type: Grant
    Filed: April 25, 1974
    Date of Patent: May 18, 1976
    Assignee: AGFA-GEVAERT N.V.
    Inventors: Marcel Jan Libeer, Frans Henri Claes
  • Hydrophilic aqueous coating composition containing aqueous binder solution and select homogeneous aqueous dispersion of polymer particles
    Patent number: 3941727
    Abstract: Polymeric particles are homogeneously dispersed in aqueous medium by a process which comprises dissolving a water-insoluble film-forming polymer in a water-insoluble, ethylenically unsaturated monomer which is liquid at room temperature. The solution formed is dispersed by stirring in an aqueous solution of a hydrophilic colloid and of a dispersing agent, stirring being continued until a stable dispersing of polymer-in-monomer solution droplets having a diameter between 1 and 10 microns, preferably between 1 and 6 micron, in said aqueous solution is obtained. While continuously stirring the dispersion in the presence of a free-radical forming polymerisation initiator, the dispersion is heated at the decomposition temperature of said polymerisation initiator to effect polymerisation of the water-insoluble, liquid monomer and to form an aqueous dispersion of solvent-free polymer particles.
    Type: Grant
    Filed: October 23, 1973
    Date of Patent: March 2, 1976
    Assignee: AGFA-GEVAERT N.V.
    Inventors: Daniel Maurice Timmerman, Victor Jan Thijs, Walter Frans De Winter, Frans Henri Claes, Hubert Vandenabeele