| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink capable of forming images excellent in adhesion and water resistance by incorporating a specific water-soluble photopolymerization initiator and at least one compound selected from among water-soluble ultraviolet-polymerizable compounds into an aqueous medium. SOLUTION: A clear ink is provided which contains 0.1-7.0 wt.% water-soluble photopolymerization initiator represented by formula I (wherein n is 2-6), 1-30 wt.% water-soluble ultraviolet-polymerizable compound, 40-90 wt.% water-soluble organic solvent (e.g. ethylene glycol) having a b, p, of 190 deg.C or lower, and a colorant such as a pigment having an average particle size of 25-250 nm. The ultraviolet-polymerizable compounds include basic reactive compounds [e.g. morpholinoethyl (meth)acrylate represented by formula II (wherein X is H or methyl)] and acidic reactive compounds [e.g. tris(acryloyloxoethoxy) phosphate represented by formula III]. A polyhydric alcohol acylic ester, a nonionic polymerizable compound, or the like having a water solubility of 10 wt.% or higher may be jointly used together with the ultraviolet-polymerizable compound. |
