Patent ID: 8097663

Claim:
A non-aqueous inkjet ink comprising: a pigment including C.I. Pigment Violet 19; and a polymeric dispersant according to Formula (I): wherein T represents hydrogen or a polymerization terminating group; Z represents the residue of hyperbranched polyethyleneimine having a number-average molecular weight of at least 100; A represents one or more oxyalkylene carbonyl groups selected from the group consisting of oxyalkylene carbonyl groups derivable from δ-valerolactone, ε-caprolactone, and C 1-4 -alkyl substituted ε-caprolactone; T-C(O)A n - represents a TPOAC-chain which is bound to Z through an amide bond; and n and m are integers wherein m is at least 2 and n is from 2 to 100; and the polymeric dispersant satisfies the conditions of: W TPOAC >57 and N Amide ≧65 mol % wherein W TPOAC represents a ratio of a weight percentage of the TPOAC-chains over a weight percentage of the amide bonds in the polymeric dispersant; N Amide represents the mol % of the amide bonds based on a total nitrogen content of the polymeric dispersant; and the values of W TPOAC and N Amide are calculated from the total nitrogen content determined by dry combustion of the polymeric dispersant and from the amine content determined through potentiometric titration in a mixture of CH 3 COOH:THF (14.5:0.5) with 0.1N aqueous perchloric acid.