Patents by Inventor Yuko Shigeta

Yuko Shigeta 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: 4767844
    Abstract: An azo lake pigment is obtained by coupling an aromatic diazo component having a sulfonic acid group with a mixture of 2-hydroxy-3-naphthoic acid and a 2-hydroxy-3-naphthoic acid derivative represented by formula [I] ##STR1## wherein R represents a hydrogen atom, a naphthalene residue, a cyclohexyl group, or a group of the formula ##STR2## in which each of X, Y and Z represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, an acetylamino group, a benzoylamino group, a carbomoyl group or a phenylcarbamoyl group, and X and Y together may form a cyclized benzimidazolone, benzthiazole or benzoxazole group,and laking the resulting dye with an alkaline earth metal salt or a manganese salt.
    Type: Grant
    Filed: August 21, 1987
    Date of Patent: August 30, 1988
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Hirohito Ando, Zenji Takada, Shigeto Aoki, Yuko Shigeta
  • Patent number: 4711674
    Abstract: A non-bronzing reddish lake pigment obtained by treating a reddish lake pigment with an N-(3-alkoxy-2-hydroxypropyl)trialkylammonium salt represented by the general formula ##STR1## wherein each of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents an alkyl group having 1 to 30 carbon atoms, and X represents a halogen atom, a sulfonic acid radical, an acetic acid radical or a formic acid radical.
    Type: Grant
    Filed: November 4, 1986
    Date of Patent: December 8, 1987
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Hirohito Ando, Zenji Takada, Yuko Shigeta