Patents by Inventor Andreas H. J. Roelofs

Andreas H. J. Roelofs 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: 5494980
    Abstract: A water-dispersible hybrid polymer comprises an ethylenically unsaturated polyurethane (core) onto which an addition polymer chain (shell) has been provided by polymerization, with the unsaturation of the polyurethane being achieved by the incorporation therein of dimethyl-m-isopropenyl benzyl isocyanate, and the acid number of the shell polymer being in the range of 30 to 120 (mg KOH/g). Aqueous dispersions of these hybrid polymers are pre-eminently suitable for use in aqueous coating compositions of the so-called clear coat type, particularly when stringent demands are imposed with regard to the acid resistance of the topcoats applied using these compositions.
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: February 27, 1996
    Assignee: Akzo Nobel NV
    Inventors: Roelof Buter, Andreas H. J. Roelofs
  • Patent number: 5190994
    Abstract: A water-dispersible hybrid polymer of a core/shell structure is provided which is based upon (A) a polymer (core) of a mercapto-functionalized poly(epoxyester) onto which (B) at least one addition polymer-based chain (shell) has been grafted via the addition polymerization of free-radically polymerizable monomers in the presence of the mercapto-functionalized poly(epoxyester). Also provided are aqueous dispersions of these hybrid polymers and coating compositions therefrom, which coating compositions are especially suited for use as clearcoats and surfacers.
    Type: Grant
    Filed: February 27, 1991
    Date of Patent: March 2, 1993
    Assignee: Akzo N.V.
    Inventors: Roelof Buter, Andreas H. J. Roelofs, Aletta Wemmenhove
  • Patent number: 4851294
    Abstract: The invention provides for a thixotropic coating composition comprising (1) a binder and (2) a sag control agent which is the reaction product of (a) a symmetrical aliphatic or homocyclic diisocyanate and (b) a monoamine or diamine having at least one primary amino group and ether group, the coating composition containing 0.1 to 30 percent by weight of the sag control agent. The invention also relates to a process for coating a substrate using said coating composition and to the coated substrate thus obtained.
    Type: Grant
    Filed: February 18, 1986
    Date of Patent: July 25, 1989
    Assignee: Akzo N.V.
    Inventors: Roelof Buter, Andreas H. J. Roelofs