Patents by Inventor Tette J. Dijkstra

Tette J. Dijkstra 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).

  • Process for preparing aqueous paint composition
    Patent number: 4933379
    Abstract: A process is disclosed for preparing an aqueous paint composition including the steps of(a) mixing a pigment powder having a particle size less than about 20 micrometers, a cross-linking agent and an epoxy resin to form a liquid, solvent-free paste;(b) reacting the resultant paste with a secondary amine to provide at least one N-H function per epoxy group of the epoxy resin; and(c) neutralizing the resulting suspension of particles coated with an epoxy-amine adduct and a cross-linking agent.Also provided is a coating process employing the invention aqueous paint composition containing a transesterification-promoting metal compound.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: June 12, 1990
    Assignee: Shell Oil Company
    Inventors: Henricus P. H. Scholten, Tette J. Dijkstra, Roeland Van Iperen
  • Epoxy-(1,1,1)trimethylol alkane copolymers
    Patent number: 4755583
    Abstract: Process for the preparation of a polyether resin by reacting a diglycidyl ether of a dihydric phenol with an alcohol of formula R-C(CH.sub.2 OH).sub.3, R being C.sub.1-4 -alkyl, using an equivalent ratio e.sub.OH to e.sub.epoxy >1 and selecting P>1.05, wherein ##EQU1## F.sub.epoxy being the epoxy functionality of the diglycidyl ether.
    Type: Grant
    Filed: May 5, 1987
    Date of Patent: July 5, 1988
    Assignee: Shell Oil Company
    Inventors: Henricus P. H. Scholten, Tette J. Dijkstra, Roeland van Iperen