Videojet Systems International, Inc.

Wing Sum Kwan

Yoshikazu Mizobuchi

Modified iron-containing pigment particles modified with an encapsulant comprising an alkylphenol and lecithin having an HLB value from about 10 to about 15. The modified iron oxide pigments made using the encapsulant exhibit enhanced dispersibility in solvents over a wide range of polarity.

Method of preparing iron-containing pigment with enhanced dispersibility

A surface derivatizing agent is allowed to contact an aqueous slurry of transition metal-containing pigment particles to increase the hydrophobicity of the surface of such particles. The modified pigment particles disperse easily in a wide variety of organic solvents, and provide stable, dispersions having a small mean pigment particle size and narrow particle size distribution.

Hydrophobic treatment of pigments

A surface coordinating agent is allowed to contact an aqueous slurry of transition metal-containing pigment particles to increase the hydrophilicity of the surface of such particles. The modified pigment particles disperse easily in a wide variety of solvents, and provide stable, dispersions having a small mean pigment particle size and narrow particle size distribution.

Hydrophilic treatment of pigments

A method for preparing modified pigment particles including contacting an aqueous slurry of metallo, mono and bi-dentate ligand pigment particles with a surface derivatizing agent having one or more phenolic moieties, a 1, 3-diketo moiety or a combination thereof.

Pigment dispersion

A method for making magnetic ink compositions is disclosed. The magnetic particles used in the ink are prepared from an aqueous slurry. A surface derivatizing agent is added to the slurry to render the magnetic pigment particles hydrophobic. The particles then sink to the bottom of the slurry, and the bulk water is then removed. After air drying, dry magnetic pigment particles are provided. The particles will be hydrophobic, and thus will have superior resistance to water as compared to previously known magnetic pigment particles. Magnetic ink compositions are formulated from the magnetic particles.

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Deerfield, IL, United States of America

Wing Sum Kwan