| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an aqueous pigment ink composition that ensures excellent recording characteristics on any type of recording mediums. <P>SOLUTION: The aqueous pigment ink composition includes a pigment, a water-dispersible polymer, water, and a water-soluble organic solvent, where the pigment is dispersed as primary particles having an average primary particle diameter of not greater than 50 nm and as secondary particles having a ratio of an average secondary particle diameter to the average primary particle diameter in a range of 1 to 10, and the water-dispersible polymer has a minimum glass transition temperature of lower than 100°C. Using this polymer achieves, with good dispersion stability, a high color density for a non-glossy medium such as plain paper and favorable glossiness on a glossy medium. <P>COPYRIGHT: (C)2012,JPO&INPIT |
