Process for preparing an ink jet ink

US6210474A · kind A · utility

Assignee

• EASTMAN KODAK COMPANY · US

Inventors

• Charles E. Romano, Jr. · Rochester, US
• Douglas E. Bugner · Rochester, US
• Richard C. VanHanehem · Rochester, US
• James R. Bennett · San Jose, US
• Dennis E. Smith · Rochester, US
• Robert A. Guistina · Rochester, US

Key dates

• Filing date: Jun 4, 1999
• Grant date: Apr 3, 2001
• Expiry date: Jun 4, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D11/322
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for making an ink jet ink comprising: PA1 a) providing an organic pigment dispersion containing a pigment and a carrier; PA1 b) mixing the pigment dispersion with rigid milling media having an average size less than about 100 .mu.m; PA1 c) introducing the mixture from step b) into a high speed mill; PA1 d) milling the mixture from step c) until a pigment particle size distribution is obtained wherein about 50% by weight of the pigment particles have a particle size less than about 100 nanometers; PA1 e) separating the milling media from the mixture milled in step d); and PA1 f) diluting the mixture from step d) to obtain the ink jet ink; wherein the milling media comprises negatively-charged polymeric beads which are crosslinked sufficiently to prevent swelling of the polymeric beads to levels greater than or equal to about 50 volume % within 4 hours at 25.degree. C. in the carrier.