Surface modified pigments and non-aqueous inks therewith

A surface modified organic pigment comprising:

• at least one functional group according to Formula (I) attached to its surface:
• wherein
• the dashed line in Formula I represents a covalent bond to one pigment molecule at a pigment surface;
• X is selected from the group consisting of OR5, SR6, NR3R7, and a halogen;
• Y is selected from the group consisting of O and NR4;
• R1 to R4 are independently selected from the group consisting of hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group, and a heteroaryl group;
• R5 to R7 are independently selected from the group consisting of hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an alkaryl group, an aryl group, and a heteroaryl group and an acyl group;
• any one of R1 to R7 may represent necessary atoms to form a five to eight membered ring with one of the other groups selected from R1 to R7;
• and
• when Y—R1 is different from OH, at least one of R2 to R7 is substituted by at least one functional group having a pKa between 2.5 and 9.