Inkjet Ink Compositions Comprising Polymeric Dispersants Having Attached Chromophore Groups

Abstract

The present invention relates to an inkjet ink composition comprising a liquid vehicle, a pigment, and a polymeric dispersant. In one embodiment, the pigment comprises a colorant having the formula A-(B) x or is a carbon black pigment and the polymeric dispersant comprises a polymeric group and at least one group having the formula -A′-(B) y (C) z , wherein A and A′ are organic chromophore groups. In a second embodiment, the polymeric dispersant comprises a polymeric group and an organic chromophore group capable of interacting with the pigment.

1 . An inkjet ink composition comprising:
 a) a liquid vehicle;   b) a pigment comprising a colorant having the formula A-(B)x; and   c) a polymeric dispersant comprising a polymeric group and at least one group having the formula -A′-(B)y(C)z,   wherein A and A′ are organic chromophore groups; B, which can be the same or different when x or y>1, is a substituent on A and N; C, which can be the same or different when z>1, is a substituent on A′ and is different than B; x, y and z are 0, 1, 2, 3 or 4; and y is less than or equal to x; and   wherein A and A′ are different.   
     
     
         2 . The inkjet ink composition of  claim 1 , wherein the polymeric dispersant comprises at least one group having the formula -LG-A′-(B)y(C)z, wherein LG is a linking group. 
     
     
         3 . The inkjet ink composition of  claim 1 , wherein z is 0. 
     
     
         4 . The inkjet ink composition of  claim 1 , wherein y is 0. 
     
     
         5 . The inkjet ink composition of  claim 1 , wherein the polymeric group comprises at least one acid group or salt thereof. 
     
     
         6 . The inkjet ink composition of  claim 1 , wherein the polymeric group is an acrylate or methacrylate polymeric group, a maleic acid or maleic anhydride polymeric group, or a polyurethane group. 
     
     
         7 . The inkjet ink composition of  claim 1 , wherein the polymeric group is a styrene-acrylic acid, a styrene-methacrylic acid, a styrene-maleic anhydride, or a styrene-maleic acid polymeric group. 
     
     
         8 . The inkjet ink composition of  claim 2 , wherein LG comprises a group having the formula —X-ALK1-, wherein X is O, NR, or S; R is hydrogen, a C1-C6 alkyl group, or an aryl group; and ALK1 is an alkylene group, an arylene group, an aralkylene group, or an alkarylene group having 1-18 carbons. 
     
     
         9 . The inkjet ink composition of  claim 8 , wherein the polymeric dispersant comprises at least one group having the formula —X-ALK1-A′-(B)y(C)z. 
     
     
         10 . The inkjet ink composition of  claim 2 , wherein the polymeric dispersant comprises at least one group having the formula —NH—CH2-A′-(B)y(C)z. 
     
     
         11 . The inkjet ink composition of  claim 2 , wherein the polymeric dispersant further comprises at least one pendant group attached to the polymeric group, wherein the pendant group comprises a group having the formula —X-ALK2, wherein X is O, NR, or S; R is hydrogen, a C1-C6 alkyl group, or an aryl group; and ALK2 is an alkyl group, an aryl group, an aralkyl group, or an alkaryl group having 1-18 carbons. 
     
     
         12 . The inkjet ink composition of  claim 11 , wherein the pendant group has the formula —X-ALK2. 
     
     
         13 . The inkjet ink composition of  claim 11 , wherein the pendant group has the formula —NH-ALK2, wherein ALK2 is a C1-C12 alkyl group. 
     
     
         14 . The inkjet ink composition of  claim 1 , wherein the pigment comprises a blue pigment, a black pigment, a brown pigment, a cyan pigment, a green pigment, a white pigment, a violet pigment, a magenta pigment, a red pigment, an orange pigment, a yellow pigment, or mixtures thereof. 
     
     
         15 . The inkjet ink composition of  claim 1 , wherein the pigment is a cyan pigment. 
     
     
         16 . The inkjet ink composition of  claim 15 , wherein the colorant is a phthalocyanine. 
     
     
         17 . The inkjet ink composition of  claim 15 , wherein A is a phthalocyaninyl group. 
     
     
         18 . The inkjet ink composition of  claim 17 , wherein A′ is a quinacridonylene group. 
     
     
         19 . An inkjet ink composition comprising:
 a) a liquid vehicle;   b) a pigment comprising a colorant having the formula A-(B)x; and   c) a polymeric dispersant comprising a polymeric group and at least one organic chromophore group capable of interacting with the pigment;   
       wherein A is an organic chromophore group; B, which can be the same or different when x>1, is a substituent on A; and x is 0, 1, 2, 3, or 4. 
     
     
         20 . The inkjet ink composition of  claim 19 , wherein the polymeric dispersant comprises at least one group having the formula -LG-Q, wherein LG is a linking group; and Q is the organic chromophore group capable of interacting with the pigment.