Patents by Inventor Yoshiaki Echigo

Yoshiaki Echigo 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: 5225296
    Abstract: An electrode comprises a porous carbon sheet comprising (a) carbon fibers and (b) a carbon matrix which comprises carbon particles and is integrally combined with the carbon fibers, having continuous through-holes. This electrode can be used as a cathode or anode for a battery. This type of electrode is prepared by depositing a phenolic resin on a phenolic resin sheet comprising phenolic resin fibers, and carbonizing the phenolic resin and the phenolic resin sheet in an oxygen-free atmosphere at temperatures in the range of 500.degree. C. to 3000.degree. C.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: July 6, 1993
    Assignees: Ricoh Company, Ltd., Unitika, Ltd.
    Inventors: Toshiyuki Ohsawa, Toshiyuki Kabata, Yoshiaki Echigo, Tutomu Sakaida, Keiichi Asami
  • Patent number: 5108862
    Abstract: Disclosed herein are composite carrier particles for electrophotography comprising 80 to 99% by weight of ferromagnetic fine particles and a phenol resin, and having a number-average particle diameter of 10 to 1,000 .mu.m, a bulk density of not more than 2.0 g /cm.sup.3, and a curved surface configuration, and a process for producing the same.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: April 28, 1992
    Assignees: Toda Kogyo Corp., Unitika Ltd.
    Inventors: Souichiro Kishimoto, Tsutomu Sakaida, Yoshiaki Echigo, Keiichi Asami, Tetsuro Toda, Kazuo Fujioka, Eiichi Kurita, Toshiyuki Hakata, Shigeru Takaragi
  • Patent number: 4942192
    Abstract: A rubber composition for use in tire, particularly bead filler comprises 2.about.30 parts by weight of a particular modified novolak resin having a self-curability based on 100 parts by weight of rubber ingredient.
    Type: Grant
    Filed: August 26, 1988
    Date of Patent: July 17, 1990
    Assignees: Bridgestone Corporation, Ltd. Unitika
    Inventors: Takuo Yasuda, Hitoshi Kondo, Yoshiaki Echigo, Tsuneyuki Ohsawa, Yoshiaki Maekawa
  • Patent number: 4839445
    Abstract: The present invention relates to a process for producing spherical thermosetting phenolic resin particles having a size of no larger than about 1,000 microns, and the spherical thermosetting phenolic resin particles produced by this process.In accordance with the process of the present invention, a novolak resin, and a nitrogenous basic compound, and, optionally, an aldehyde, are reacted while they are suspended in an aqueous medium in the presence of a suspension stabilizer.The thermosetting phenolic resin produced by the process of the present invention not only displays superior thermal curing characteristics during molding; the cured product fabricated by molding this resin also exhibits good physical properties such as improved mechanical strength and heat resistance. Therefore, the spherical thermosetting phenolic resin particles produced by the process of the present invention can be extensively used as molding materials, binders, adhesives, and in many other applications.
    Type: Grant
    Filed: January 6, 1988
    Date of Patent: June 13, 1989
    Assignee: Unitika, Ltd.
    Inventors: Yoshiaki Echigo, Kenichi Sugawara, Mutsunori Yamao, Yoshiyuki Suematu, Keiichi Asami, Tuneyuki Ohsawa
  • Patent number: 4808316
    Abstract: A process for treating a waste water containing uranium and fluorine comprises a neutralizing precipitation step wherein slaked lime is added to the waste water containing uranium and fluorine and precipitate thus formed in separated and removed, and an adsorption step wherein supernatant from the neutralizing precipitation step is contacted with a chelating resin which can selectively adsorb fluorine ions and another chelating resin which can selectively adsorb uranyl ions to thereby adsorb and remove the fluorine and uranyl ions remaining in the supernatant. Eluates of the ions adsorbed by the chelating resins and waste liquors for washing and regeneration of these resins are returned to the neutralizing precipitation step. Prior to the neutralizing precipitation step, a decarbonation step may be provided for decomposing carbonate ions, if they are contained in the waste water to be treated.
    Type: Grant
    Filed: February 4, 1987
    Date of Patent: February 28, 1989
    Assignees: Unitika Ltd., Doryokuro Kakunenryo Kaihatsu Jigyodan
    Inventors: Keiichiro Otomura, Yoshikazu Ogura, Yoshiaki Echigo, Mutsunori Yamao, Tadashi Ishikura
  • Patent number: 4778695
    Abstract: A resole resin in the form of microspherical particles whose surfaces are partly or entirely covered with a coating of a substantially water-insoluble inorganic salt and which are not larger than 500 .mu.m in size, and a process for producing such resole resin. The resole resin comprises solid particles that are highly heat reactive and can be stored in a stable manner for a prolonged period. The resin particles can be used with good results in all fields of applications (e.g., moldings, laminations and binders) where conventional phenolic resins are used.
    Type: Grant
    Filed: October 3, 1986
    Date of Patent: October 18, 1988
    Assignee: Unitika Ltd.
    Inventors: Yoshiaki Echigo, Mutsunori Yamao, Yoshiyuki Suematu, Tadashi Ishikura, Keiichi Asami, Ritsuko Shidei
  • Patent number: 4769180
    Abstract: A process for separately recovering uranium and hydrofluoric acid from a waste liquor containing uranium and fluorine comprises a neutralizing precipitation step wherein a magnesium compound is added to the waste liquor containing uranium and fluorine to form a precipitate and the thus formed precipitate is then separated; a distillation step wherein an aqueous solution of sulfuric acid is added to the precipitate separated in said neutralizing precipitation step to dissolve the precipitate and the thus formed solution is then distilled to recover hydrofluoric acid as a distillate; and a uranium recovery step wherein uranium is recovered from a residue produced by said distillation step.
    Type: Grant
    Filed: April 1, 1987
    Date of Patent: September 6, 1988
    Assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
    Inventors: Yoshiaki Echigo, Hirotaka Amimoto, Mutsunori Yamao, Tadashi Ishikura, Keiichiro Otomura, Sakae Fujisaki, Yoshikazu Ogura
  • Patent number: 4748214
    Abstract: A process for producing microspherical cured phenolic resin particles having a particle diameter of not more than about 100 .mu.m, which comprises reacting a novolak resin, a phenol and an aldehyde in an aqueous medium in the presence of a basic catalyst and an emulsion stabilizer. Novel microspherical cured phenolic resin particles are produced by this process. The resin particles have excellent impact strength and mechanical properties, a sharp particle size distribution, and a low secondary agglomerate content, and because of these properties, are useful as an excellent modifier or filler for various plastics and rubbers.
    Type: Grant
    Filed: May 13, 1986
    Date of Patent: May 31, 1988
    Assignee: Unitika Ltd.
    Inventors: Keiichi Asami, Yoshiaki Echigo, Mutsunori Yamao, Yoshiyuki Suematu, Tadashi Ishikura, Ritsuko Shidei
  • Patent number: 4640971
    Abstract: A resole resin in the form of microspherical particles whose surfaces are partly or entirely covered with a coating of a substantially water-insoluble inorganic salt and which are not larger than 500 .mu.m in size, and a process for producing such resole resin. The resole resin comprises solid particles that are highly heat reactive and can be stored in a stable manner for a prolonged period. The resin particles can be used with good results in all fields of applications (e.g., moldings, laminations and binders) where conventional phenolic resins are used.
    Type: Grant
    Filed: July 17, 1985
    Date of Patent: February 3, 1987
    Assignee: Unitika Ltd.
    Inventors: Yoshiaki Echigo, Mutsunori Yamao, Yoshiyuki Suematu, Tadashi Ishikura, Keiichi Asami, Ritsuko Shidei
  • Patent number: 4576969
    Abstract: A spherical ion exchange resin composed of a phenolic resin and a metal hydroxide is disclosed. The metal hydroxide is enclosed and bound with the phenolic resin. A method for producing such an ion exchange resin and a method for selectively adsorbing ions using the same is also disclosed. The ion exchange resin is capable of efficiently recovering ions contained or dissolved in water in trace amounts and, hence, can be applied to any aqueous solution containing ions. For example, it can be used to recover useful substances from sea water and to purify waste waters from nonferrous refineries and nuclear power plants.
    Type: Grant
    Filed: October 13, 1983
    Date of Patent: March 18, 1986
    Assignee: Unitika Ltd.
    Inventors: Yoshiaki Echigo, Yoshiyuki Suematsu, Tadashi Ishikura
  • Patent number: 4559216
    Abstract: A method for purification of a sulfuric acid solution such as, for example, a copper electrolyte which entrains at least one metal ion species selected from the group consisting of antimony ions, bismuth ions, and iron ions and having a sulfuric acid concentration of at least 50 g/liter is disclosed. The method comprises exposing the sulfuric acid solution to a chelating resin possessing aminomethylenephosphonic acid group as a chelate forming group thereby effecting adsorptive separation of the aforementioned at least one metal ion species from the solution. By the method described above, the antimony ions, bismuth ions, and/or iron ions contained as impurities in the copper electrolyte can be easily and efficiently separated out of the system without entailing any ecological problem.
    Type: Grant
    Filed: March 5, 1984
    Date of Patent: December 17, 1985
    Assignee: Unitika Limited
    Inventors: Tadao Nagai, Yoshiaki Echigo
  • Patent number: 4414183
    Abstract: The phenolic chelate resin has a chelate-forming group wherein part or all of the hydrogen atoms in a primary and/or secondary alkylamino group introduced in a phenol nucleus are replaced by a methylenephosphonate group. Also disclosed is a process for producing such a chelate resin, and a method for recovering heavy metal ions with such a resin. The resin has particularly high selectivity for adsorbing uranium ions, as well as high heat, acid and alkali resistance as well as dimensional stability. The resin is very effective for recovering uranium from various uranium-containing solutions such as sea water, crude phosphoric acid fertilizer solutions, low-grade uranium ore, waste water from uranium refining, and uranium mine water.
    Type: Grant
    Filed: July 20, 1982
    Date of Patent: November 8, 1983
    Assignee: Unitika Ltd.
    Inventors: Akio Sasaki, Yoshiaki Echigo
  • Patent number: 4383104
    Abstract: The phenolic chelate resin has a chelate-forming group wherein part or all of the hydrogen atoms in a primary and/or secondary alkylamino group introduced in a phenol nucleus are replaced by a methylenephosphonate group. Also disclosed is a process for producing such a chelate resin, and a method for recovering heavy metal ions with such a resin. The resin has particularly high selectivity for adsorbing uranium ions, as well as high heat, acid and alkali resistance as well as dimensional stability. The resin is very effective for recovering uranium from various uranium-containing solutions such as sea water, crude phosphoric acid fertilizer solutions, lowgrade uranium ore, waste water from uranium refining, and uranium mine water.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: May 10, 1983
    Assignee: Unitika Ltd.
    Inventors: Akio Sasaki, Yoshiaki Echigo