Cabot Corporation

Hewlett-packard Company

Ronald J Gambale

Robert M Amici

Curtis E Adams

Dennis P Parazak

Yuan Yu

Joseph E Johnson

David J Halko

Patricia A Wang

J Christine Bedford

The present invention relates to a process for preparing a polymer-modified pigment comprising the step of: combining, in any order, at least one pigment having attached at least one nucleophilic group, at least one polymer comprising at least one carboxylic acid group or salt thereof, and at least one coupling agent. At least one mediator compound may also be used. The modified pigments can be used in applications such as inkjet ink applications.

Process for preparing modified pigments

The present invention relates to a process for preparing surface-modified colored pigments. The process includes the steps of: preparing a reaction batch comprising a treating agent and a diazotizing agent; adding a colored pigment to the batch; and mixing the colored pigment and the batch under high shear conditions to form a reaction product comprising a surface-modified colored pigment. The treating agent has an organic group which comprises at least one diazotizable group. In a preferred embodiment the diazotizable group comprises a) at least one aromatic group or at least one C -C alkyl group, and b) at least one ionic group, ionizable group, nonionic group, or a mixture thereof. The surface-modified colored pigments prepared by the process of the present invention have been found useful in aqueous or solvent based compositions and particularly in ink jet ink compositions.

Process for preparing colored pigments

An ink composition is disclosed which comprises at least one ink vehicle, at least one colorant and at least one metal oxide. The colorant may be a dye or a pigment, or both, and the colorant is non-reactive with the metal oxide in the ink vehicle. Also disclosed are inkjet formulations using the above-described compositions and methods of improving such properties as optical density.

Ink compositions containing metal oxides

The ink of the invention comprises a vehicle and a colorant. The colorant is a water-insoluble pigment that has been chemically modified to be water dispersable by addition of functional groups to the surface of the pigment resulting in water soluble colorant particles. The performance of these pigments is improved by the addition of specific functional groups which provide improved black to color bleed control and high waterfastness.

Superior waterfastness and bleed control with specifically treated pigments for ink-jet printing

The ink of the invention comprises a vehicle and a macromolecular chromophore colorant. The colorant is a water-insoluble pigment that has been chemically modified to be water dispersible by addition of functional groups to the surface of the pigment resulting in water dispersible colorant particles. The performance of these pigments is improved by the addition of specific functional groups which provide improved black to color bleed control and high waterfastness.

Growing community of inventors

Wakefield, MA, United States of America

Ronald J Gambale