| abstract |
A process for making an ink jet ink comprising: a) providing a dispersion containing a pigment, a hydrocarbon carrier, and a polyamine/fatty acid condensation polymer dispersant; b) mixing the pigment dispersion with rigid milling media less than 100 mu m; c) introducing the mixture of step (b) into a mill; d) milling the mixture from step (c) until the pigment particle size is below about 100 nanometers (nm); e) adding to the mixture during or after step d) or f) (below) a stabilizer selected from the group consisting of a polyether polyol; a modified polyester resin; an acrylic polymer; an alkylol ammonium salt of a block copolymer having acidic groups; ethoxylated triethanolamine; a high molecular weight block copolymer having an amine functionality; sorbitan sesquioleate; polyhydroxy stearic acid; butylated polyvinyl pyrrolidone; poly(vinylpyrrolidone/1-hexadecene); and poly(p-tert-butylstyrene-co-styrene-co-2-sulfoethyl-lithium methacrylate); f) separating the milling media from the mixture milled in step (d); and g) diluting the mixture to obtain an ink jet ink having a pigment concentration suitable for ink jet printers. |