Inkjet dyes exhibiting reduced kogation

摘要

A sulfonated dye salt of formula (II): wherein M is Ga(A1); A1 is an axial ligand selected from the group consisting of: —OH and halogen; and Z1+, Z2+, Z3+ and Z4+ are independently selected from the group consisting of: H and an ammonium cation. At least one of Z1+, Z2+, Z3+ and Z4+ is the ammonium cation. The ammonium cation is protonated 2,2-bis(hydroxymethyl)-2,2′,2″-nitrilotriethanol. Such salts exhibit reduced kogation in thermal bubble-forming inkjet printheads.