Patents Represented by Attorney, Agent or Law Firm Robert Maggio
  • Heterogeneous chromium catalysts and processes of polymerization of olefins using same
    Patent number: 6734131
    Abstract: A chromium containing catalyst wherein the chromium atom is in one of its higher valence states and is immobilized to a support-agglomerate composed of at least one inorganic oxide component and at least one ion-containing layered component.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: May 11, 2004
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Keng-Yu Shih, Dean Alexander Denton, Rimantas Glemza
  • High pore volume polyolefin catalyst
    Patent number: 6670302
    Abstract: High melt index polyolefins have been obtained with chromium silica catalysts under conventional polymerization conditions without the use of titanium or other additives. The useful chromium silica catalysts have a pore volume in the range of 1.9-2.9 cc/g and a narrow pore size distribution. The silica is a silica gel preferably obtained from a low solids, rapid gelation process.
    Type: Grant
    Filed: October 31, 2002
    Date of Patent: December 30, 2003
    Assignee: W. R. Grace & Co.-Conn
    Inventors: Rimantas Glemza, Dean A. Denton
  • Polyimide membranes for hyperfiltration recovery of aromatic solvents
    Patent number: 6180008
    Abstract: Improved asymmetric hyperfiltration membranes and their method of preparation and use are disclosed. The membranes are fashioned from polyimides and conditioned with a lubricating oil. Permselective separation of aromatic hydrocarbons from non-aromatic hydrocarbons in a feed stream may be accomplished using the membranes under hyperfiltration conditions.
    Type: Grant
    Filed: July 30, 1998
    Date of Patent: January 30, 2001
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Lloyd Steven White