Propylene polymerization patent, Natta

Ziegler-Natta catalysts can polymerize a variety of structurally different monomers. Examples of stereoregular homopolymers (Table IV), elastomeric or crystalline copolymers, as well as block copolymers may be found in the patent and open literature (, 49-51). Ethylene polymerizes easily with many soluble and heterogeneous Ziegler catalysts. Some ethylene-active catalysts, for example, Cp2TiCl2 + aluminum alkyl (52). are not active for a-olefin polymerizations. However, all known Ziegler catalysts that polymerize propylene are also active in ethylene polymerization. 

Karl Ziegler of the Max Planck Institut patented the polymerization of ethylene at ordinary pressures and temperatures in the presence of titanium chloride-triethylaluminum (ffiegler catalyst) but he did not include propylene in his patent application. Hogan and Banks at Phillips and Zletz at Standard Oil of Indiana polymerized propylene in the presence of metal oxides. Ed Vandenburg at Hercules, S.B. lippincott of Standard Oil of New Jersey, and B. Wright of Petrochemicals LTD (Shell), like Natta, re( ived licenses to use the Ziegler catalyst. 

The polymerization of propylene was repeated successfully by H. Martin some months later in May of 1954. Ziegler then filed a patent application and after sending a sample to Dr. Natta, learned that Natta had filed a patent application on the polymerization of propylene several days earlier. 

When Ziegler s patent attorney suggested that he include propylene as well as ethylene in his low pressure pol3rmerization patent application, his reply was "Es Geht Nicht." Breil supported this negative attitude when he noted very little decrease in pressure during the formation of polypropylene. When asked why he did not inform Dr. Ziegler that he had produced solid polypropylene. Dr. Natta replied," I did not tell him because I had to take out patents first. I asked him whether he had polymerized propylene in order to know whether my process was new."... 

I. Valvassori, A. Zambelli, A. Copolymers of ethylene, higher a-olefins, and monocyclomonool-efins or aUcyl derivatives thereof. U.S. Patent 3,505,301 (Montecatini Edison S.p.A.), April 7, 1970. (b) Zambelli, A. Tosi, C. Sacchi, C. Polymerization of propylene to syndiotactic polymer. VI. Monomer insertion. Macromolecules 1972, 5, 649-654. (c) LocateUi, R Immirzi, A. Zambelli, A. Palumbo, R. Maglio, G. Orientation of propylene units in polypropylene and ethylene/propylene copolymers. Makromol. Chem. 1975,176, 1121-1128. (d) Carman, C. J. Harrington, R. A. Wilkes, C. E. Monomer sequence distribution in ethylene-propylene rubber measured by C NMR. 3. Use of reaction probability mode. Macromolecules 1977, 10, 536-544. (e) Zucchini, U. Dall Occo, T. Resconi, L. Ziegler-Natta catalysis for the polyolefin industry Present status and perspectives. Indian... 

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