Patents by Inventor Tetuo Nakajo

Tetuo Nakajo 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).

  • Catalyst, process for preparation of same and process for polymerization of olefins using same
    Patent number: 5208302
    Abstract: Disclosed is a catalyst composition for use in the polymerization of olefins, which is comprised of (a) a catalyst component containing magnesium, titanium, a halogen, and an ingredient derived from a keto-ester compound, and (b) an organic aluminum compound. The catalyst activity and capability of providing a highly stereoregular polymer are enhanced by preparing the catalyst component (a) by a process wherein, during or after the formation of a solid catalyst component containing magnesium, titanium, and a halogen, the solid catalyst component is treated with a keto-ester of the formula: ##STR1## wherein R.sup.1, R.sup.2 and Z represent a hydrocarbon group.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: May 4, 1993
    Assignee: Showa Denko K.K.
    Inventors: Tetuo Nakajo, Hisayoshi Yanagihara, Masaki Fushimi, Shigenobu Miyake, Hideki Sakurai
  • Catalyst, process for preparation of same, and process for polymerization of olefins using same
    Patent number: 5049533
    Abstract: Disclosed is a catalyst composition for use in the polymerization of olefins, which is comprised of (a) a catalyst component containing magnesium, titanium, a halogen, and an ingredient derived from a keto-ester compound, and (b) an organic aluminum compound. The catalyst activity and capability of providing a highly stereoregular polymer are enhanced by preparing the catalyst component (a) by a process wherein, during or after the formation of a solid catalyst component containing magnesium, titanium, and a halogen, the solid catalyst component is treated with a keto-ester of the formula: ##STR1## wherein R.sup.1, R.sup.2 and Z represent a hydrocarbon group.
    Type: Grant
    Filed: July 11, 1990
    Date of Patent: September 17, 1991
    Assignee: Showa Denko K.K.
    Inventors: Tetuo Nakajo, Hisayoshi Yanagihara, Masaki Fushimi, Shigenobu Miyake, Hideki Sakurai
  • Catalyst process for preparation of same, and process for polymerization of olefins using same
    Patent number: 5041403
    Abstract: Disclosed is a catalyst composition for use in the polymerization of olefins, which is comprised of (a) a catalyst component containing magnesium, titanium, a halogen, and an ingredient derived from an ester compound, and (b) an organic aluminum compound. The catalyst activity and capability of providing a highly stereroregular polymer are enhanced by preparing the catalyst component (a) by a process wherein, during or after the formation of a solid catalyst component containing magnesium, titanium, and a halogen, the solid catalyst component is treated with an ester of the formula:(R.sup.1 O).sub.i (R.sup.2 O).sub.j (R.sup.3 O).sub.k --Z--COOR.sup.4 (I)whereinR.sup.1, R.sup.2, R.sup.3 and R.sup.4 are an aliphatic, alicyclic, aromatic, polycyclic or heterocyclic compound group,Z is an aliphatic or alicyclic hydrocarbon group in which hydrogen may be substituted with an aromatic or polycyclic group,and i, j and k are integers of 0 to 3 with the proviso that the sum of i, j and k is at least 1.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: August 20, 1991
    Assignee: Showa Denko K.K.
    Inventors: Tetuo Nakajo, Masaki Fushimi, Shigenobu Miyake, Hideki Sakurai