| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ink that strikes a balance between ink reliability excellent in recovery from fixation in a recording head, in which the ink is prevented from being accumulated in a cap, and image characteristics excellent in image density and bleeding resistance. <P>SOLUTION: The ink contains a self-dispersing pigment, a salt, and a water-soluble organic compound. The self-dispersing pigment is such that a functional group containing a phosphonic acid group is bonded to a particle surface, wherein the introduction amount of the functional group is 0.34 to 0.40 mmol/g. The salt is configured by making a cation selected from an alkali metal ion, an ammonium ion, and an organic ammonium ion bond to an anion selected from a halide ion and the like. The value obtained by multiplying the concentration of the anion of the salt by the valence of the anion, in the ink, is 0.01-0.04 mol/L. The water-soluble organic compound contains an ethylene urea, wherein the content of the ethylene urea is 22-50 mass% based on the total content of the water-soluble organic compound in the ink. <P>COPYRIGHT: (C)2012,JPO&INPIT |
