Patents by Inventor Fuminao Watanabe

Fuminao Watanabe 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).

  • Continuous production method of propylene-based block copolymer
    Patent number: 6646044
    Abstract: A stable continuous production of a propylene-based block copolymer can proceed for a long time without causing accumulation of particles having a small diameter by a process having the following steps: (1) polymerizing an &agr;-olefin containing liquid propylene as a main component in the presence of hydrogen and a stereoregular polymerization catalyst in one or more polymerization reactors to obtain a polymer slurry; (2) feeding the polymer slurry to a copolymerization reactor; and (3) copolymerizing propylene and an &agr;-olefin other than propylene substantially in a gaseous phase in the presence of the stereoregular polymerization catalyst, the polymer slurry and a deactivating compound in the copolymerization reactor to obtain a propylene-block copolymer powder.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: November 11, 2003
    Assignee: Japan Polychem Corporation
    Inventors: Fuminao Watanabe, Eiji Tanaka, Jun Hosoi
  • Method of estimating gel content of propylene block copolymer
    Patent number: 6466875
    Abstract: A concentration distribution of a rubber component in block copolymer particles is computed based on the operating conditions of a polymerization apparatus, a growth model equation of polymer particles on a solid catalyst component, and a residence time distribution of the particles in each of a homopolymerization stage and a copolymerization stage, and the gel content of the block copolymer is estimated based on the computation. The gel content of a propylene block copolymer can thereby be estimated precisely.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: October 15, 2002
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Kenji Mitsutani, Glen H. Ko, Kiyoshi Yukawa, Fuminao Watanabe
  • Propylene block copolymer
    Patent number: 6191232
    Abstract: The present invention provides a propylene block copolymer comprising polymer particles whose rubber-like component contents are 50% by weight or more, in an amount less than 1.0% by weight of the whole polymer particles finally discharged from a polymerization system.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: February 20, 2001
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Kenji Mitsutani, Kiyoshi Yukawa, Fumihiko Shimizu, Glen H. Ko, Eiji Tanaka, Fuminao Watanabe