text: 1-Olefin polymerization catalyst United States Patent 04411821
  04411821 is referenced by 37 patents and cites 11 patents.
  Improved 1-olefin polymerization catalyst system, and process employing same, comprising a reaction product of alumina and an organometallic compound of the formula (RCH.sub.2).sub.4 M wherein M is Ti, Zr or Hf and R is a group which is such that there is no hydrogen atom attached to an atom which is in the .beta.-position to M, the improvement characterized in that the preformed catalyst system is controlled in its mode of action and is protected from impurities by mixing with it an oxide, hydroxide, or carbonate of magnesium, calcium, strontium, or barium.
  Edward G Howard Jr
  Edward G Howard Jr, Walter Mahler: Large pore alumina-supported transition metal alkyl. E I Du Pont de Nemours and Company, December 8, 1981: US04304685 (5 worldwide citation)
  Elastomeric polypropylene and process for its production. Du Pont, January 24, 1979: GB2001080-A (6 worldwide citation)
  Edward G Howard Jr, Christos Sarafidis: Polymerization of propylene with a catalyst prepared in situ. E I Du Pont de Nemours and Company, October 14, 1980: US04228263 (9 worldwide citation)
  John W Collette, Charles W Tullock: Fractionable, elastomeric poly (1-butene). E I Du Pont de Nemours and Company, James A Costello, November 3, 1981: US04298722 (20 worldwide citation)