Patent ID: 6585815
Filing Date: 2003-07-01
Classification: C09D

Abstract:
An ink set comprising first, second and third inks respectively containing aqueous media and coloring materials;said first ink containing an anionic dye as coloring material; said second ink containing an anionic dye as coloring material and having a lower coloring material content than that of said first ink; said third ink containing a first pigment, a second pigment and a polymeric dispersant for dispersing said second pigment, both said first pigment and said second pigment being contained in said third ink in a dispersed state; said first pigment being a self-dispersible pigment and having an anionic group bound to the surface directly or via another atomic group; said second pigment being dispersible to said aqueous medium by means of said polymeric dispersant; said polymeric dispersant being at least either an anionic polymeric dispersant or a nonionic polymeric dispersant; said second ink further containing a substance which destabilizes the dispersion stability of at least either the first pigment or the second pigment in said third ink when the second ink is brought into contact with said third ink in a liquid state on a printing medium.