Patents by Inventor P. Scott Chisholm

P. Scott Chisholm 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: 6235853
    Abstract: A slurry polymerization process uses an unsupported catalyst component which is an organometallic complex having a phosphinimine ligand and a cyclopentadienyl-type ligand. The use of the unsupported catalyst component allows simple, inexpensive catalyst addition techniques to be used in a slurry polymerization process. The catalyst component is highly active for ethylene (co)polymerization in the process of this invention.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: May 22, 2001
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Ian McKay, Dusan Jeremic, Qinyan Wang, P. Scott Chisholm
  • Patent number: 6235671
    Abstract: A heterogeneous catalyst for olefin polymerization is prepared by spray drying a mixture of a metallocene catalyst, a cocatalyst and a hydrotalcite. It Preferred hydrotalcites are magnesium-aluminum hydroxy carbonates. The catalysts are very active for ethylene polymerization. The hydrotalcite used in this invention are generally defined by the formula: (Mg1−x Alx(OH)2)n+An−x/n·m H2O wherein X is from 0 to 0.5, m is from 0 to 20 and An− is an anion having a charge of n. Preferred hydrotalcites are those in which the anion A is a carbonate and which have been dried of adsorbed water.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: May 22, 2001
    Assignee: Nova Chemicals (International) S.A.
    Inventors: Ian McKay, Alison Ciupa, P. Scott Chisholm
  • Patent number: 5854352
    Abstract: The extrusion of thermoplastic polyolefin, especially linear low density polyethylene (LLDPE) is improved by the use of a processing additive comprising a blend of a thermoplastic acrylic polymer and a fluorocarbon polymer. In a preferred embodiment, the processing additive is a homogeneous blend of a thermoplastic styrene/methyl methacrylate polymer and a thermoplastic copolymer of vinylidene fluoride and hexafluoropropylene. The polyolefin extrudates produced according to this invention have reduced levels of melt fracture when extruded in conventional polymer extrusion equipment.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: December 29, 1998
    Assignee: Nova Chemical Ltd.
    Inventors: P. Scott Chisholm, Tony Tikuisis, Shivendra Kumar Goyal, Douglas Checknita, Nick Klaus Kurt Bohnet
  • Patent number: 5661098
    Abstract: A catalyst prepared by firstly depositing a large amount of aluminoxane on a particulate support, then depositing a small amount of monocyclopentadienyl zirconium trihalide on the support. The catalyst is active for the polymerization of ethylene, optionally with a minor amount of other alpha olefins such as butene or hexene, particularly in a gas phase process.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: August 26, 1997
    Assignee: Novacor Chemicals Ltd.
    Inventors: Daryll G. Harrison, P. Scott Chisholm