| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an excellent water-based pigment ink for ink jet recording that is capable of meeting the demands for still more increased recording speed as well as still more decreased particle size of jetted ink liquid particles despite the use of a pigment never undergoing a high level of purification treatment when the ink is prepared by dispersing a pigment as a water-insoluble coloring material into an aqueous medium by using a resin dispersant. <P>SOLUTION: The ink is a water-based pigment ink for ink jet recording that contains at least a pigment, a water-soluble compound and water and the total content of calcium and magnesium is in the range of from 50 ppm to 130 ppm. The average particle size of the pigment is ≤ 95 nm. Further, this ink includes 1-6 mass% of a block polymer bearing a carboxylic acid as a solubilizing functional group. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
