Patents by Inventor Shyozo Kawamata

Shyozo Kawamata 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 producing propylene block copolymers
    Patent number: 4433110
    Abstract: A propylene block copolymer produced by polymerizing propylene, ethylene and an .alpha.-olefin having 4 to 8 carbon atoms in two stages with a Zieglar-Natta catalyst by a process which comprises (A) supplying propylene and ethylene in the first stage and propylene and the .alpha.-olefin in the second stage, or (B) supplying propylene and the .alpha.-olefin in the first stage and propylene and ethylene in the second stage, to the polymerization system, wherein the amounts of propylene and ethylene supplied in the first stage of (A) or in the second stage of (B) are 90 to 99 wt % and 10 to 1 wt % based on the total amount of propylene and ethylene supplied in the first stage of (A) or in the second stage of (B), respectively, the amounts of propylene and the .alpha.-olefin supplied in the second stage of (A) or in the first stage of (B) are 60 to 98 wt % and 40 to 2 wt % based on the total amount of propylene and the .alpha.
    Type: Grant
    Filed: April 17, 1981
    Date of Patent: February 21, 1984
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Kazuo Baba, Shyozo Kawamata, Yoshiharu Fukui, Seiichiro Ima, Tatsuya Miyatake