INKJET PRINTING FLUID

摘要

An inkjet printing fluid composition including water and a water dispersible polyurethane additive of the general formula of (I) wherein Z is the central portion of a monomer unit that is the polymerization product of a diisocyanate; X1-Y1-X1 represents one or more soft segments wherein Y1 represents the central portion of a unit that is the polymerization product of a diamine or diol prepolymer having a molecular weight of greater than 300 Daltons; W is the central portion of one or more units containing an acid group; X2-Y2-X2 represents one or more hard segments wherein Y2 represents the central portion of a unit that is the polymerization product of a C2-C8 diol or diamine having a molecular weight of less than 250 Daltons; and X1, V and X2 can be the same or different and are an -O- or -N- atom; and further wherein the polyurethane additive has a weight average molecular weight of at least 6,000 Daltons and a sufficient number of acid groups to provide an acid number greater than 35, and the one or more X2-Y2-X2 hard segments are present at from 1 wt % to less than 13 wt % of the polyurethane additive. Also disclosed is a method for printing an inkjet image including I) providing an inkjet printing fluid according to the invention; and II) jetting the inkjet printing fluid in the form of ink drops onto a recording element to form a printed image.