| abstract |
To provide an ink composition capable of printing or printing characters and images having excellent metallic luster by an ink jet printing method. An organic compound having a carboxyl group (particularly a C6-34 alicyclic hydroxycarboxylic acid such as cholic acid) and a polymer dispersant having a carboxyl group are used as a metal compound corresponding to the metal nanoparticle (A1). A dispersion comprising metal colloid particles (A) that are reduced in a solvent in the presence of the protective colloid (A2) and the reducing agent, and the metal nanoparticles (A1) are coated with the protective colloid (A2). An ink composition for inkjet printing is produced. The metal constituting the metal nanoparticles (A1) may be a metal (in particular, silver) containing at least a noble metal, and the average particle diameter of the metal nanoparticles (A1) is about 1 to 100 nm. [Selection figure] None |