| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide ink for use in ink jet printing that has superior frequency responsibility and durability of a printed image when used in the ink jet printing and is less prone to degrade these characteristics when stored, and a printing unit etc., using the ink. <P>SOLUTION: The ink for use in the ink jet printing comprises at least an aqueous medium, a water insoluble color material and a resin dispersant suitable for dispersing the color material in the aqueous medium. The resin dispersant is a block copolymer having a hydrophilic moiety and a hydrophobic moiety, in which the ratio of the hydrophilic moiety is ≥20% by molar ratio of the total amount of the resin. A hydrophilic group of the hydrophilic moiety has water solubility in a form of a salt composed of a carboxyl group and a base. A content of the base in the ink is adjusted so as to be ≥80% of a stoichiometric amount required to neutralize all of the carboxyl group. An effective solubilization index of the carboxyl group in the ink is ≥70%. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
