E.i. Dupont De Nemours and Company

Tristan Williams

Michael Stephen Wolfe

Christian Jackson

Xiaoqing Li

Hee Hyun Lee

Michael Joseph Otley

Harry J Spinelli

Charles T Berge

Patrick F McIntyre

C Chad Roberts

James A Silver

Howard Zakheim

John C Hornby

The present disclosure provides an aqueous dispersion containing a colorant and a polyurethane dispersant, wherein the polyurethane dispersant is a polymer having a cross-linkable moiety, wherein the cross-linkable moiety is cross-linked, with a cross-linking agent.

Cross-linked pigment dispersion based on polyurethane dispersants

The present disclosure provides an inkjet ink comprising an aqueous vehicle and an encapsulated pigment dispersion. A process for encapsulating pigment dispersions is provided where a pigment is dispersed with a polymeric dispersant in an aqueous solvent system. The free polymer dispersant in the pigment dispersion is limited to less than 0.12 grams per gram of pigment. This dispersed pigment is then encapsulated by adding acrylate monomers and optionally acrylic and vinyl monomers and polymerizing. In the encapsulated pigment dispersion the weight ratio of final free polymer to polymer found to the final encapsulated pigment is less than 0.9. The free polymer dispersant is measured by a centrifugation method and the final free polymer is measured by a density gradient centrifugation method. Such encapsulated pigment dispersions may be used in inkjet inks and are stable to heat, aging test conditions, and solvent challenges. Prints from these inks have better durability.

Ink jet ink comprising encapsulated pigment dispersions with minimal free polymer

A process for preparing a crossed-linked colorant dispersion is provided in which a partially neutralized dispersant polymer having a cross-linkable moiety is used as a dispersant for a colorant by reacting the cross-linkable moiety on the dispersant with a cross-linking agent.

Method of preparing cross-linked colorant dispersions

A process for encapsulating pigment dispersions is provided where a pigment is dispersed with a polymeric dispersant in an aqueous solvent system. The free polymer dispersant in the pigment dispersion is limited to less than 0.12 grams per gram of pigment. This dispersed pigment is then encapsulated by adding acrylate monomers and optionally acrylic and vinyl monomers and polymerizing. In the encapsulated pigment dispersion the weight ratio of final free polymer to polymer found to the final encapsulated pigment is less than 0.9. The free polymer dispersant is measured by a centrifugation method and the final free polymer is measured by a density gradient centrifugation method. Such encapsulated pigment dispersions may be used in inkjet inks and are stable to heat, aging test conditions, and solvent challenges. Prints from these inks have better durability.

Method of preparing encapsulated pigment dispersions with minimal free polymer

A process for preparing dispersions of particles, especially aqueous dispersions is described. The process relates to a dispersion process where a polar solvent is added during the dispersion process such that the hydrogen bonding solubility parameter component, &#x3b4;, of the initial dispersion mixture increases at least 1.5 units. When the polar solvent added is water the dispersion process is called a Solvent-to-Water Process.

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Cary, NC, United States of America

Tristan Williams