Fuji Xerox Co., Ltd.

Kyoko Horinouchi

Ken Hashimoto

Toshitake Yui

Nobuyuki Ichizawa

Atsushi Suzuki

Takatsugu Doi

Kunichi Yamashita

In an aqueous ink jet recording liquid including at least water, a water-soluble organic solvent and a water-insoluble coloring material, (1) the absolute value of the zeta potential is 20 mV or more, (2) the conductivity is from 0.05 to 0.75 S/m, (3) the number average particle size of dispersed particles is from 15 to 200 nm, and (4) the number of particles having a particle size of 0.5 &mgr;m or more present in one liter is 2.5&times;10 or less. Due to the aforementioned, dispersion stability of the coloring material can be maintained in the ink jet recording liquid in which the water-insoluble coloring material is dispersed, and the aqueous ink jet recording liquid is provided, which is excellent regarding stability over long periods of time, causes no ink flow route clogging and prevents kogation in printing, provides a recorded material having excellent rub resistance, printing quality, optical density, water resistance and lightfastness, and can prevent uneven density.

Aqueous ink jet recording liquid and ink jet recording method

An ink for ink jet printing which contains as essential components pigment, water-soluble organic solvent, and water. The ink contains particles, after ink jetting, such that the number-average particle diameter is 10 to 150 nm and the number of particles larger than 0.5 &mgr;m is 6&times;10 to 6&times;10 /&mgr;l and the number of particles larger than 5 &mgr;m is less than 50/&mgr;l. This ink may be used in combination with a second liquid which contains a water-soluble organic solvent having a solubility parameter of 9 to 11, and/or surfactant, and water. A method of ink jet printing uses the ink or a combination of the ink and the liquid. The ink possesses the characteristics of both optical density and storage stability. The liquid prevents the mixing of colors of adjacent printed images.

Ink for ink jet printing

Growing community of inventors

Minami-ashigara, Japan

Kyoko Horinouchi