Patents by Inventor Sinjiro Kawasaki

Sinjiro Kawasaki 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: 4592756
    Abstract: A dye solution composition containing a black dye obtained by the action of at least one acid or its salt:HO(CH.sub.2).sub.n SO.sub.3 H, Cl(CH.sub.2).sub.n COOH, Br(CH.sub.2).sub.n COOH (n=1 or 2)on one or a mixture of dyes of the formula (I): ##STR1## wherein R is phenylene or naphthylene residue; X and X' are each H, sulfonic acid group or sulfonate group; Y and Y' are each H or alkali metal; R' is one of amino group-containing radicals: ##STR2## (the carboxyl group may be carboxylate group and the sulfonic acid group may be sulfonate group), except that when R' has not sulfonic acid group, X and X' are not the same and when R' has sulfonic acid group, X and X' are H. This is highly stable, preservative and water soluble, and is useful as ink composition for ball-point pen and ink jet recording.
    Type: Grant
    Filed: February 6, 1985
    Date of Patent: June 3, 1986
    Assignee: Taoka Chemical Company, Limited
    Inventors: Sinjiro Kawasaki, Hideo Kitagawa, Yutaka Nishii