Patents by Inventor Takahiro Takeda

Takahiro Takeda 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: 6407096
    Abstract: Benzene fused derivatives represented by the following formula: having strong TXA2 receptor antagonistic action and PGI2 receptor agonistic action, and effective for treating or preventing diseases concerning TXA2.
    Type: Grant
    Filed: May 4, 2000
    Date of Patent: June 18, 2002
    Assignee: Toray Industries, Inc.
    Inventors: Atsushi Ohtake, Michihiro Ohno, Kazuhiro Hoshi, Takahiro Takeda, Naohiro Yamada
  • Patent number: 6323235
    Abstract: Novel compounds having strong TXA2 receptor antagonist activities and PGI2 receptor agonist activities, which are effective for therapy and prevention of diseases related to TXA2, are disclosed. The compound of the present invention is represented by the following formula (I). (wherein the meanings of the symbols in the formula are as described in the specification).
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: November 27, 2001
    Inventors: Atsushi Ohtake, Kazuhiro Hoshi, Shunji Tsukamoto, Takahiro Takeda, Naohiro Yamada, Kazuhisa Matsumoto, Michihiro Ohno, Kiyotaka Ohno
  • Patent number: 6252110
    Abstract: A method for recovering acrylic acid from high boiling impurities containing acrylic acid dimer, acrylic acid and maleic acid at high efficiency with stability which includes the steps of (1) introducing said high boiling impurities containing acrylic acid dimer, acrylic acid and maleic acid into an acrylic acid recovery column, distilling acrylic acid from the column top and recovering the same, (2) introducing bottom liquid A from said acrylic acid recovery column into a pyrolyzing tank to decompose the acrylic acid dimer in the bottom liquid A, and (3) recirculating at least a part of bottom liquid B from said pyrolyzing tank into the acrylic acid recovery column.
    Type: Grant
    Filed: June 25, 1998
    Date of Patent: June 26, 2001
    Assignee: Nippon Shokubai Co LTD
    Inventors: Masahiro Uemura, Takahiro Takeda, Masatoshi Ueoka
  • Patent number: 6084127
    Abstract: An improved method which enables stable and effective recovery of acrylic acid over a prolonged period is provided, said method comprising contacting an acrylic acid-containing gas obtained upon gas-phase catalytic oxidation of propylene and/or acrolein, with water, whereby collecting the acrylic acid in form of an aqueous solution, introducing said aqueous solution into an azeotropic separation column and distilling it in the presence of an azeotropic solvent to isolate and recover the acrylic acid, in which polymerization of the acrylic acid in the azeotropic separation column is prevented. Said method is characterized by using as the azeotropic solvent either a mixed solvent composed of solvent A (eg., ethyl acrylate, methyl methacrylate, etc.) and solvent B (eg., toluene, heptane, etc.) (first embodiment) or the solvent A alone (second embodiment).
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: July 4, 2000
    Assignee: Nippon Shokubai Co Ltd
    Inventors: Kazuhiko Sakamoto, Fumio Shibusawa, Sei Nakahara, Takahiro Takeda, Masatoshi Ueoka
  • Patent number: 6043264
    Abstract: Novel compounds having strong TXA.sub.2 receptor antagonist activities and PGI.sub.2 receptor agonist activities, which are effective for therapy and prevention of diseases related to TXA.sub.2, are disclosed. The compound of the present invention is represented by the following formula (I). ##STR1## (wherein the meanings of the symbols in the formula are as described in the specification).
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: March 28, 2000
    Assignee: Toray Industries, Inc.
    Inventors: Atsushi Ohtake, Kazuhiro Hoshi, Shunji Tsukamoto, Takahiro Takeda, Naohiro Yamada, Kazuhisa Matsumoto, Michihiro Ohno, Kiyotaka Ohno, deceased
  • Patent number: 5892103
    Abstract: The present invention provides a process for producing a carboxylic acid ester by reacting a carboxylic acid with an alcohol in a suspension of a strongly acidic cation exchange resin which is a catalyst, which process comprises introducing a reaction mixture slurry containing said ion exchange resin, from a reactor for the above reaction to a resin-separating vessel, separating, in said resin-separating vessel, said reaction mixture slurry into a clear solution and a slurry-like high-concentration mixture, and discharging the clear solution from the upper section of the resin-separating vessel and the slurry-like high-concentration mixture from near the bottom of the resin-separating vessel to circulate it into the reactor. Preferably, the resin-separating vessel is operated under such conditions that the ascending speed of the clear solution becomes 0.003 m/sec or less. The process allows efficient separation/recovery of ion exchange resin from reaction mixture and reuse of recovered resin in the reaction.
    Type: Grant
    Filed: December 15, 1997
    Date of Patent: April 6, 1999
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Hideki Sogabe, Takahiro Takeda
  • Patent number: 5785821
    Abstract: The present invention provides an improved process for production of acrylic acid by subjecting propylene and/or acrolein to catalytic gas-phase oxidation with a molecular oxygen-containing gas. In the process, the mixed gas obtained by the catalytic gas-phase oxidation is contacted with an aqueous collecting agent containing acrylic acid, acetic acid and a poorly-soluble-in-water solvent, to form an aqueous acrylic acid solution; and the aqueous acrylic acid solution is subjected to azeotropic distillation in the presence of a poorly-soluble-in-water solvent to remove by-products and obtain high-purity acrylic acid.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: July 28, 1998
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Sei Nakahara, Takahiro Takeda, Masatoshi Ueoka, Yohji Akazawa
  • Patent number: 5504243
    Abstract: Disclosed herein is a method for inhibiting polymerizable (meth)acrylic acid and esters thereof from polymerizing during their production, transportation and storage by using as the inhibitor N-oxyl compound and more than one compound selected from the group consisting of manganese salt compound, copper salt compound, 2,2,6,6,-tetramethylpiperidine compound and nitroso compound. The N-oxyl compound is one or more kinds selected from 2,2,6,6,-tetramethylpiperidinooxyl, 4-hydroxy-2,2,6,6,-tetramethylpiperidinooxyl and 4,4',4"-tris-(2,2,6,6,-tetramethylpiperidinooxyl)phosphite. The combined use of the inhibitors provides superior inhibiting effect to use alone.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: April 2, 1996
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Takahiro Takeda, Masatoshi Ueoka, Yoji Akazawa, Masao Baba
  • Patent number: 5322960
    Abstract: Disclosed herein is a method for inhibiting polymerizable (meth)acrylic acid and esters thereof from polymerizing during their production and storage by using as the inhibitor N-oxyl compound, phenol compound, and phenothiazine compound in combination with one another. The combined use of the three inhibitors provides superior inhibiting effect to use alone alone or in pairs.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: June 21, 1994
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Takahiro Takeda, Masatoshi Ueoka, Yoji Akazawa, Masao Baba
  • Patent number: 5139980
    Abstract: A method for the production of inorganic oxide particles by a procedure comprising the steps of dispersing inorganic oxide particles as seed particles in a water-containing alcohol solution thereby preparing a suspension of said seed particles and adding a hydrolyzable and condensable organic metal compound to said suspension thereby effecting growth of said seed particles, which method further comprises causing the presence in said water-containing alcohol solution of an alkylene glycol having 2-8 carbon atoms, in an amount in the range of 1 to 50% by weight, based on the amount of said water-containing alcohol solution.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: August 18, 1992
    Assignee: Nippon Shokubai Kagaku Kogyo Co., Ltd.
    Inventors: Saburo Nakahara, Takahiro Takeda, Mitsuo Takeda, Youji Akazawa, Tadahiro Yoneda