Patent ID: 8324293
Filing Date: 2012-12-04
Classification: C09D

Abstract:
1. An aqueous ink jet ink comprising: a pigment; a water-soluble organic solvent comprising a water-soluble organic solvent (a) selected from the group consisting of 2-pyrrolidone, N-methyl-2-pyrrolidone, and 1,1,1-trimethylolpropane, and a water-soluble organic solvent (b) selected from the group consisting of glycerol and diethylene glycol, wherein a total content of the water-soluble organic solvent in the ink is between 7.0 mass % and to 50.0 mass % based on the total mass of the ink, and a content of the water-soluble organic solvent (a) is more than a content of the water-soluble organic solvent (b); and a polymer comprising a segment A having hydroxyl groups and a segment B having no hydroxyl groups, some of the polymer being adsorbed by the pigment and some of the polymer not being adsorbed by the pigment, wherein the polymer is selected such that the water-soluble organic solvent (a) is a poor medium for the non-adsorbed polymer and a good medium for either one of the segment A and the segment B and such that the water-soluble organic solvent (b) is a good medium for both the segment A and the segment B wherein a content of the water-soluble organic solvent, which is a poor medium for the non-adsorbed polymer and is also a good medium for either one of the segment A and the segment B, has a content 10 times or more as much as a content of the non-adsorbed polymer.