Patents by Inventor Jacob Renkema

Jacob Renkema 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).

  • Elastomeric copolymer and process for the preparation thereof
    Patent number: 6465584
    Abstract: The invention relates to an elastomeric copolymer derived from components comprising a) ethylene, b) an &agr;-olefin, c) a non-conjugated polyene (C) having one C═C bond that is copolymerizable using a Ziegler-Natta catalyst, and d) optionally a non-conjugated polyene (D) which in the molecule contains two or more C═C bonds that are copolymerizable using a Ziegler-Natta catalyst. The copolymer is characterized by, inter alia, a specific branching coefficient BC. The invention also relates to a process for the preparation of such copolymers.
    Type: Grant
    Filed: December 27, 1999
    Date of Patent: October 15, 2002
    Assignee: DSM N.V.
    Inventors: Georges G. Evens, Emanuel M. J. Pijpers, Andreas A. Oosterlaken, Jacob Renkema, Henri J. H. Beelen
  • Catalyst system for the preparation of a rubbery copolymer
    Patent number: 6150483
    Abstract: The invention relates to a catalyst system and a process suited for the preparation of a rubbery copolymer of ethylene, one or more .alpha.-olefins and optionally one or more polyunsaturated compounds, in which the catalyst system comprises a vanadium compound, an organometal compound and optionally a promoter, characterized in that the organometal complex in the catalyst system is an imido complex that satisfies the general formula(R.sub.u -X.sup.1.sub.v -Me.sup.1).sub.n =NR.sup.1 (I)where each individual Me.sup.1 is a metal chosen from group 1, 2, 12 or 13 of the Periodic System of Elements, each individual R is hydrogen or a hydrocarbon group having 1-20 C atoms, N--R.sup.1 is an imido group where R.sup.1 is hydrogen or a hydrocarbon group having 1-20 C atoms or a group with the general formula MR.sup.3.sub.3, where M is an element chosen from group 14 of the Periodic System of Elements, each individual R.sup.3 is hydrogen, a hydrocarbon group having 1-20 C atoms or a heteroatom-containing group, X.sup.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: November 21, 2000
    Assignee: DSM N.V.
    Inventors: Jacob Renkema, Peter J. H. Windmuller
  • Branched polymers with polyolefin arms
    Patent number: 6084030
    Abstract: A highly branched polymer in the form of a comb, star, nanogel and structural combinations thereof in which a plurality of polyolefin arms formed of polymers of 1-alkenes are attached to a backbone having repeating units containing aliphatic groups, aromatic groups, heteroatom-containing groups and combinations thereof.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: July 4, 2000
    Assignee: DSM Copolymer, Inc.
    Inventors: Koen Jan Gerarda Janssen, Gerardus Arnoldus Rademakers, Jacob Renkema, Petronella Danielle Verweij
  • Process for the preparation of an elastomeric polymer from ethylene, alpha-olefine and optionally diene
    Patent number: 5902867
    Abstract: The invention relates to a process for the preparation of a polymer from ethylene, an .alpha.-olefine and optionally a diene, according to which these monomers are polymerized under the influence of a metallocene catalyst, the polymerization taking place in the presence of a catalyst comprising a specific 2-indenyl metallocene, resulting in a bimodal, elastomeric polymer with a molecular weight distribution of more than 3.5, under such reaction conditions that the amount of water in the polymerization medium is smaller than 0.5 ppm.The invention also relates to polymers with a specific branching index.
    Type: Grant
    Filed: December 26, 1996
    Date of Patent: May 11, 1999
    Assignee: DSM NV
    Inventors: Bernardus J. Muskens, Jacob Renkema
  • Catalyst and process for a ziegler polymerisation
    Patent number: 5688733
    Abstract: The present invention relates to a catalyst. The catalyst contains a transition metal-imidoaryl complex which contains at least one amido group bound to the transition metal and wherein the aryl group is a 2,6-di-substituted phenyl group. The catalyst can be used in polymerizing olefins. The transition metal is chosen from groups 3-6 of the periodic table.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: November 18, 1997
    Assignee: DSM N.V.
    Inventors: Jacob Renkema, Jeroen H. G. Konings
  • Catalyst and process for the preparation of an olefin polymer
    Patent number: 5364916
    Abstract: The present invention relates to a catalyst and a process for the preparation of an olefin polymer, which catalyst comprises a transition metal component and an organometal component. The transition metal component comprises a transition metal atom onto which an imidoaryl ligand is bound.More specifically the transition metal is vanadium or titanium.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: November 15, 1994
    Assignee: DSM N.V.
    Inventors: Jacob Renkema, Jeroen H. G. Konings, Bernardus J. Muskens