Patents by Inventor Takeichi Shiraishi

Takeichi Shiraishi 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).

  • Process for preparing polyolefins
    Patent number: 4064334
    Abstract: According to the present invention, there is provided a process for preparing polyolefins by polymerizing or copolymerizing olefins in the presence of a catalyst consisting of a solid component and an organometallic compound component, characterized in that said solid component is obtained by copulverizing1. a magnesium halide,2. a compound represented by the general formula Al(OR)mX.sub.3-m wherein R is alkyl and/or aralkyl having 1 to 20 carbon atoms and may be the same or different, X is halogen and O<m.ltoreq.3,3. a tetravalent titanium compound, and4. a trivalent titanium compound and in that said organometallic compound component is a mixture of5. a trialkylaluminum and6. a compound represented by the general formula AlR'nX.sub.3-n wherein R' is alkyl having 1 to 10 carbon atoms and may be the same or different, X is halogen and O<n<3.
    Type: Grant
    Filed: July 15, 1976
    Date of Patent: December 20, 1977
    Assignee: Nippon Oil Company Ltd.
    Inventors: Nobuyuki Kuroda, Toru Nakamura, Takeichi Shiraishi, Kazuo Matsuura, Mituji Miyoshi
  • Process for preparing polyolefins
    Patent number: 4061857
    Abstract: According to the present invention, there is provided a process for preparing polyolefins which comprises polymerizing or copolymerizing olefins using as catalyst a solid component containing a titanium compound and/or a vanadium compound, and an organoaluminum compound and/or an organozinc compound, said solid component being obtained by copulverizing (1) a magnesium halide and/or a manganese halide, (2) an aluminum oxyhalide and (3) a titanium compound and/or a vanadium compound.
    Type: Grant
    Filed: May 6, 1976
    Date of Patent: December 6, 1977
    Assignee: Nippon Oil Company Ltd.
    Inventors: Nobuyuki Kuroda, Takeichi Shiraishi, Akio Itoh, Kazuo Matsuura, Mituji Miyoshi
  • Polymerization of olefins and catalysts therefor
    Patent number: 4006101
    Abstract: A process for the production of polyolefins is disclosed, which is carried out in the presence of catalysts prepared according to the invention. The catalysts comprise a carrier resulting from the reaction of anhydrous magnesium halide, silicon tetrachloride and an alcohol represented by the general formulaROHwhere R is an organic group of 1 to 20 carbon atoms, and a titanium and/or a vanadium compound supported on said carrier. Such catalysts are activated by an organoaluminum and/or an organozinc compound when in use.
    Type: Grant
    Filed: August 29, 1975
    Date of Patent: February 1, 1977
    Assignee: Nippon Oil Company Ltd.
    Inventors: Kazuo Matsuura, Nobuyuki Kuroda, Takeichi Shiraishi, Mitsuji Miyoshi
  • Process for preparing polyolefins
    Patent number: 3991260
    Abstract: Process for preparing polyolefins by polymerizing or copolymerizing olefins in the presence of an organometallic compound and a catalyst comprising magnesium, titanium and aluminum or magnesium, vanadium and aluminum, the catalysts being prepared by copulverizing a magnesium dihalide, an aluminum alkoxide and a titanium or vanadium compound.
    Type: Grant
    Filed: October 7, 1974
    Date of Patent: November 9, 1976
    Assignee: Nippon Oil Corporation Ltd.
    Inventors: Kazuo Matsuura, Nobuyuki Kuroda, Takeichi Shiraishi, Mituji Miyoshi