Self-dispersing pigment and process of making and use of same

US6852156B2 · kind B2 · utility

Assignee

• E.I. DU PONT DE NEMOURS AND COMPANY · US

Inventors

• An-Gong Yeh · Broomall, US
• Michael J. Eiseman · Swarthmore, US
• Robert P. Held · Englishtown, US
• James Hohman · Newark, US
• Dhiren V. Patel · Hockessin, US
• Yia-Ching Ray · Palisades Park, US
• Harry J. Spinelli · Wilmington, US
• Sandra Witman · Wilmington, US

Key dates

• Filing date: May 23, 2001
• Grant date: Feb 8, 2005
• Expiry date: Aug 11, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/22
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process is provided in which a pigment is oxidated with ozone in an aqueous environment in which the mixture of ozone, water and pigment is subjected to a dispersive mixing operation; and/or the pH of the mixture is maintained in a range of 6-8, whereby the pigment is self-dispersing and preferably has an acid value of less than 3 μmoles/M2. Pigments from this process and ink jet inks containing the self-dispersing pigments, are also provided.