Patent ID: 7745510
Filing Date: 2010-06-29
Classification: C09D

Abstract:
1. An ink composition for ink jet recording comprising at least a resin emulsion and a surface-treated pigment, wherein the amount of monomers and oligomers with a molecular weight of 2,000 or less contained in the resin emulsion is 1,000 ppm or less based on the total amount of the ink composition, wherein the content of the resin emulsion is within the range of 1 to 10% by weight based on the total amount of the ink composition, wherein the surface-treated pigment is a surface-treated pigment which is dispersed by a carboxyl group existing on a surface of the pigment and without a dispersing agent, and wherein the resin emulsion is present in the ink composition in an amount such that the ink composition has good fixing and storage properties in accordance with the following criteria: (a) when a pattern including printed letters is printed with the ink to form a recorded matter and the recorded matter is air dried for 24 hours, the printed letters do not smudge when rubbed twice with a water-based yellow fluorescent pen; and (b) when sixty grams of the ink composition is hermetically sealed in a 100-g bottle and left to stand at 70 C for 1 week, the viscosity of the ink composition before and after standing changes at a rate of less than +/−5% as measured with an oscillating viscometer.