Patent ID: 6638350
Filing Date: 2003-10-28
Classification: C01P,C07C,C09C

Abstract:
An ink jet ink composition comprising an ink vehicle, from about 0.1 to about 10% by weight self-dispersed ink pigment; from about 0.1 to about 10% by weight dye; a humectant selected from the group consisting of dipropylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, 1,(2,-hydroxyethyl)-2-pyrrolidone, trimethyolpropane, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 2-pyrrolidone, polyethylene glycol, diethylene glycol, 2,2-thiodiethanol, and mixtures thereof; and a penetrant selected from the group consisting of 1,2-hexandiol, hexyl carbitol, diethylene glycol butyl ether, diethylene glycol benzyl ether, n-propyl alcohol, secondary alcohol ethoxylates, ethoxylated acetylenic diols, polyalkyleneoxide-modified heptamethyl-trisiloxane, and mixtures thereof, wherein the weight ratio of ink pigment to dye ranges from greater than about 0.75:1 to less than about 2.5:1, and wherein the self-dispersed ink pigment comprises an oxidized carbon black having a surface containing a steric inducing group thereon obtained by reacting the carbon black with thionyl halide and a steric inducing compound selected from the group consisting of a monoalkoxy-terminated polyalkylene glycol, a mono-amine terminated polyalkylene glycol compound, 2-hydroxyethylpyrrolidinone, 2-hydroethylmorpholine, and 2-hydroxyethyloxazolidone.