Patents by Inventor Leonid S. Grigoryan

Leonid S. Grigoryan 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).

  • Magnetic composition, magnetic toner and ink containing the magnetic composition
    Patent number: 5597405
    Abstract: A magnetic composition contains an alkali-metal-doped tetraazaporphyrin derivative which is prepared by doping a tetraazaporphyrin derivative of formula (I) with an alkali metal, or an alkali-metal-doped porphyrin derivative which is prepared by doping porphyrin derivative of formula (II) with an alkali metal: ##STR1## wherein M represents at least one metal or a plurality of metals; and A represents two individual hydrogen atoms, or a condensation substituent. A magnetic toner and a magnetic ink contain the above magnetic composition as the magnetic component thereof.
    Type: Grant
    Filed: December 7, 1995
    Date of Patent: January 28, 1997
    Assignees: Ricoh Company, Ltd., Leonid S. Grigoryan, Kyuya Yakushi
    Inventors: Leonid S. Grigoryan, Kyuya Yakushi
  • Magnetic composition, magnetic toner and ink containing the magnetic composition
    Patent number: 5506079
    Abstract: A magnetic composition contains an alkali-metal-doped tetraazaporphyrin derivative which is prepared by doping a tetraazaporphyrin derivative of formula (I) with an alkali metal, or an alkali-metal-doped porphyrin derivative which is prepared by doping porphyrin derivative of formula (II) with an alkali metal: ##STR1## wherein M represents at least one metal or a plurality of metals; and A represents two individual hydrogen atoms, or a condensation substituent. A magnetic toner and a magnetic ink contain the above magnetic composition as the magnetic component thereof.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: April 9, 1996
    Assignees: Ricoh Company, Ltd., Leonid S. Grigoryan, Kyuya Yakushi
    Inventors: Leonid S. Grigoryan, Kyuya Yakushi