| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermal-printing ink composition for an ink jet recorded in a decolored state, having a sufficient color density when colored, having a high coloring speed and a high decoloring speed, and excellent in printing stability. SOLUTION: The ink composition for ink jet thermal printing comprises a coloring agent consisting of a reversible heat sensitive material, a wetting agent and a solvent or dispersant, and after an image is printed with the ink composition on a recording sheet having a color developing agent applied on it, the recording sheet is heated at a specified temperature to color or discolor the printed image. The reversible heat-sensitive material is a dye of the general formula I (wherein, n is an integer of 1 to 4), and the content of coloring agent in the ink composition is 1-5 wt.%. |
