Patent ID: 8759418

Claim:
An aqueous colorant dispersion comprising a comprising a colorant and a urea terminated polyurethane ionic dispersant in an aqueous vehicle, wherein: (a) at least some of the ionic dispersant is physically adsorbed to the colorant, (b) the polymeric ionic dispersant stably disperses the pigment in the aqueous vehicle, (c) the volume average particle size of the dispersion is less than about 300 nm, wherein the urea terminated polyurethane dispersant comprises at least one compound of the general Structure (I): R 1 is alkyl, alkyl substituted with an ionizable or ionic group, alkyl/aryl from a diisocyanate substituted with an ionizable or ionic group, R 3 is alkyl, branched alkyl, or an isocyanate reactive group from an amine terminating group, R 4 is hydrogen, alkyl, branched alkyl, or an isocyanate reactive group from the amine terminating group; wherein the isocyanate reactive group is selected from the group consisting of hydroxyl, carboxyl, mercapto, and amido; n is 2 to 30; and wherein R 2 is at least one Z 2 and at least one Z 1 or Z 3 ; Z 2 is a diol substituted with an ionic group; p is greater than or equal to 1, m is equal to 2 to about 12; where q is 1 to about 4 and s is 0, or 1 to about 4; R 5 , R 6 each is independently selected from the group consisting of hydrogen, alkyl, alkyl substituted with an ionizable or ionic group, and aryl; where the R 5 or R 6 are the same or different with each substituted methylene group; where the R 5 or R 6 can be joined to form a cyclic structure; R 7 is a urethane or urea grafted alkyl, aryl or fluorocarbon chain; Z 6 is a bond or an ether linkage; e and f are 1 to 6, Z 4 is N or CR 8 , where R 8 is hydrogen, alkyl or aryl, R 7 is as defined above, wherein the urea content of the urea-terminated polyurethane is at least 2 wt % of the polyurethane and at most about 14 wt % of the polyurethane, and further wherein the colorant is selected from pigments and disperse dyes or combinations of pigments and disperse dyes.