| abstract |
Pigmented inks are disclosed comprising an aqueous medium, a pigment, a dispersant, and a humectant. Inks are disclosed where the humectant is a sulfonated polyethylene oxide which provides long decap times and fast drying of the printed image. Inks are further disclosed where the dispersant is an alkyl(sulfophenoxy)benzenesulfonic acid or its salt. Such dispersants reduce the agglomeration of pigment particles and reduce or eliminate the deposition of foreign substances on heater elements during the jetting process. A variety of pigments, dispersants, humectants, and aqueous media can be used. Combinations of a sulfonated polyethylene oxide humectant and an alkyl(sulfophenoxy)benzenesulfonic acid (salt) dispersant provide inks with good stability, few kogation problems, long decap times and relatively fast drying times. |