Patents by Inventor Tsukasa Maekawa

Tsukasa Maekawa 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).

  • Patent number: 6399201
    Abstract: A powder comprising a blowing agent powder core which is coated with at least one oil-like substance on its surface, and a process for producing a powder comprising a blowing agent powder core which is coated with at least one oil-like substance on its surface, comprising the following steps (a) and (b): (a) adding at least one oil-like substance in the form of a mist to a blowing agent powder; and (b) mixing the oil-like substance with the blowing agent powder under such mixing conditions that the blowing agent powder is less susceptible to pulverization.
    Type: Grant
    Filed: July 10, 1998
    Date of Patent: June 4, 2002
    Assignee: Otsuka Chemical Co., Ltd.
    Inventors: Tsukasa Maekawa, Toshinori Takao, Sadafumi Shono, Chiaki Yasumaru, Shigeru Sumitomo, Nobuyuki Ueda, Yoshifumi Tachi
  • Patent number: 6355698
    Abstract: It provides a blowing agent which is significantly inhibited from solidification and is exceedingly useful as a blowing agent satisfactory in flowability, dispersibility into resins, and the like, even after the lapse of a prolonged period of time, and a process for producing the same. The blowing agent of the present invention is substantially anhydrous blowing agent, and it is obtained by treating a blowing agent with a surface-treating agent capable of removing water from the blowing agent, followed by optionally heating during or after the treatment.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: March 12, 2002
    Assignee: Otsuka Chemical Co., Ltd.
    Inventors: Tsukasa Maekawa, Nobuyuki Ueda, Sadafumi Shono, Yoshifumi Tachi, Shigeru Sumitomo
  • Publication number: 20020025988
    Abstract: It provides a blowing agent which is significantly inhibited from solidification and is exceedingly useful as a blowing agent satisfactory in flowability, dispersibility into resins, and the like, even after the lapse of a prolonged period of time, and a process for producing the same.
    Type: Application
    Filed: March 22, 2000
    Publication date: February 28, 2002
    Inventors: TSUKASA MAEKAWA, NOBUYUKI UEDA, SADAFUMI SHONO, YOSHIFUMI TACHI, SHIGERU SUMITOMO
  • Patent number: 5981764
    Abstract: 1-Aminopyrrolidine which is obtained by reacting hydrazine hydrate with a compound represented by the following formula (I):X.sup.1 --C.sub.4 H.sub.8 --X.sup.2 (I)wherein X.sup.1 and X.sup.2 are the same or different, and each represents a leaving group, in methanol; and a process for producing 1-aminopyrrolidine, comprising the step of reacting hydrazine hydrate with the above compound represented by formula (I) in methanol.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: November 9, 1999
    Assignee: Otsuka Chemical Co., Ltd.
    Inventors: Tsukasa Maekawa, Yoshihisa Tomotaki, Keiichiro Ishikawa, Akihiro Nabeshima, Tomohiro Furuichi
  • Patent number: 5241117
    Abstract: This invention provides a process for preparing semicarbazide comprising reacting the compound of the formula (I) ##STR1## with ammonia in the absence or presence of chloride, hydroxide, sulfate, carbonate, acetate, salicylate, ammine complex or ethylenediamine complex of zinc or of cadmium, or a mixture thereof as catalyst. This process has the advantage of being free of the use of sodium hydroxide in large amounts or formation of byproduct sodium carbonate.
    Type: Grant
    Filed: August 13, 1992
    Date of Patent: August 31, 1993
    Assignee: Otsuka Kagaku Kabushiki Kaisha
    Inventors: Tsukasa Maekawa, Hiroyasu Hayashi, Kazusaki Kamiya
  • Patent number: 4465867
    Abstract: A process for preparing o-methallyloxyphenol by reacting catechol with methallyl chloride in the presence of at least one of KI and NaI serving as a catalyst with use of a base, and an organic solvent or a mixture of an organic solvent and water, the process being characterized in that methallyl chloride is reacted with the catalyst after the reaction to recover the catalyst as converted to methallyl iodide and reuse the catalyst.
    Type: Grant
    Filed: June 11, 1982
    Date of Patent: August 14, 1984
    Assignee: Otsuka Kagaku Yakuhin Kabushiki Kaisha
    Inventors: Tsukasa Maekawa, Takeshi Gondo, Shigeo Takahashi, Hidetoshi Kume
  • Patent number: 4465868
    Abstract: A process for preparing o-methallyloxyphenol characterized in that catechol and methallyl chloride are reacted with use of:A. at least one base selected from among carbonates and bicarbonates of alkali metals, bicarbonates of alkaline earth metals and amines at least 10 in pKa,B. at least one catalyst selected from among iodides of alkali metals or alkaline earth metals, hydrogen iodide and methallyl iodide, andC. a ketone solvent or ketone-water mixture solvent.
    Type: Grant
    Filed: June 11, 1982
    Date of Patent: August 14, 1984
    Assignee: Otsuka Kagaku Yakuhin Kabushiki Kaisha
    Inventors: Tsukasa Maekawa, Takeshi Gondo, Syozo Hayase
  • Patent number: 4451662
    Abstract: A process for preparing 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran which comprises subjecting o-methallyloxyphenol to a rearrangement and cyclization reactions in the presence of, as a catalyst, aluminum halide and N-substituted aniline derivative, or a complex of both these compounds.
    Type: Grant
    Filed: June 11, 1982
    Date of Patent: May 29, 1984
    Assignee: Otsuka Kagaku Yakuhin Kabushiki Kaisha
    Inventors: Tsukasa Maekawa, Takeshi Gondo