Patents by Inventor Akira Kumagae

Akira Kumagae 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).

  • Non-conjugated cyclic diene, non-conjugated cyclic diene composition and method of producing polymer based on non-conjugated cyclic diene
    Patent number: 7141631
    Abstract: It is an object of the present invention to provide a non-conjugated cyclic diene and a non-conjugated cyclic diene composition which enable the production of a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity, and a method of producing a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity. A non-conjugated cyclic diene is used which meets at least one of the following requirements: (1) it contains a compound having a seven-membered cyclic triene hydrocarbon structure in a specific amount or less and (2) it contains a conjugated polyene compound having an eight-membered bicyclic hydrocarbon structure in a specific amount.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: November 28, 2006
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Toshio Murakami, Hidetatsu Murakami, Yasuhiro Takano, Kenji Doi, Akira Kumagae, Yasuhiro Hasada, Toshizi Nishimura
  • Non-conjugated cyclic diene, non-conjugated cyclic diene composition and method of producing polymer based on non-conjugated cyclic diene
    Publication number: 20050131182
    Abstract: It is an object of the present invention to provide a non-conjugated cyclic diene and a non-conjugated cyclic diene composition which enable the production of a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity, and a method of producing a polymer based on non-conjugated cyclic diene which makes it possible to produce a (co)polymer at a high degree of polymerization activity. A non-conjugated cyclic diene is used which meets at least one of the following requirements: (1) it contains a compound having a seven-membered cyclic triene hydrocarbon structure in a specific amount or less and (2) it contains a conjugated polyene compound having an eight-membered bicyclic hydrocarbon structure in a specific amount.
    Type: Application
    Filed: November 4, 2004
    Publication date: June 16, 2005
    Applicant: MITSUI CHEMICALS, INC.
    Inventors: Toshio Murakami, Hidetatsu Murakami, Yasuhiro Takano, Kenji Doi, Akira Kumagae, Yasuhiro Hasada, Toshizi Nishimura
  • Three-level neutral point clamping type inverter circuit
    Patent number: 6226192
    Abstract: In a three-level neutral point clamping type inverter circuit which includes a positive bus line (4), a negative bus line (5) and a neutral line (6), wherein first and second IGBTs (11), (12) are connected in series between the positive bus line (4) and a phase voltage output terminal (10) and third and fourth IGBTs (13), (14) are connected in series between the negative bus line (5) and the phase voltage output terminal (10), the three-level neutral point clamping type inverter circuit further includes a first snubber capacitor (21) provided between the positive bus line (4) and the neutral line (6), a second snubber capacitor (22) provided between the negative bus line (5) and the neutral line (6), a first snubber diode (23) having a cathode coupled to the positive bus line (4) and an anode coupled to the phase voltage output terminal (10), and a second snubber diode (24) having an anode coupled to the negative bus line (5) and a cathode coupled to the phase voltage output terminal (10).
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: May 1, 2001
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Katsutoshi Yamanaka, Kenji Yamada, Akira Kumagae, Takaaki Terada