Patents by Inventor Jan H. Janssens

Jan H. Janssens 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: 4614708
    Abstract: Method for the preparation of stable aqueous dispersions of finely divided solid spherical polymer beads having an average particle size between about 0.5 and about 5 .mu.m and having a glass transition temperature of at least 40.degree. C. by dissolving in an aqueous solvent mixture at least one .alpha.,.beta.-ethylenically unsaturated monomer capable of forming a polymer that is soluble in the monomer(s) present in said aqueous solvent mixture but which is insoluble in said aqueous solvent mixture, a free radical-forming polymerization initiator, and a graft-polymerizable polymer containing hydrophilic groups, heating the solution to a temperature from 50.degree. C. to the reflux temperature thereof with stirring so as to form said polymer beads. The polymer beads can be used in an antifriction surface layer, an antihalation surface layer, an antistatic surface layer, or in a protective surface layer of a photographic element or in a top layer of a drafting film containing a photosensitive layer.
    Type: Grant
    Filed: February 16, 1984
    Date of Patent: September 30, 1986
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Daniel M. Timmerman, Jan J. Priem, Jan H. Janssens