| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink composition having high fixing speed and free from print-through. SOLUTION: In this ink composition, transmission amount of ultrasonic wave measured by using a paper medium in which a time (maximum transmission time of ultrasonic wave) required to make transmission amount of ultrasonic wave measured when water is absorbed in paper maximum is >=1 sec is <=90% per sec. In the ink composition, preferably, decreasing rate (maximum decreasing oblique angle) per unit time of transmission amount of ultrasonic wave is >=50% and frequency of ultrasonic wave is 2 MHz. |
