| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-soluble ink composition for dry offset printing, which can prevent generation of greasing at long-run printing. <P>SOLUTION: The ink composition comprises (a) a pigment, (b) a binder resin exhibiting solubility or dispersibility to a water-soluble organic solvent in the presence of a basic compound, (c) a water-soluble organic solvent, (d) a basic compound, (e) a hydrophilic silicone oil, and (f) a vegetable oil and/or a fatty acid ester originated from a vegetable oil. The binder resin (b) comprises at least one binder resin (1) selected from the group consisting of rosin-modified maleic resins and copolymer resins obtained by copolymerizing radically polymerizable monomers composed of an acid group-containing monofunctional monomer and another monofunctional monomer, and a binder resin (2) obtained by copolymerizing radically polymerizable monomers composed of 99.9 to 99.5 mass% of the total of an acid group-containing monofunctional monomer and another monofunctional monomer and 0.1 to 0.5 mass% of a polyfunctional monomer; and the binder resin (2) is contained in 1 to 6 mass% in the ink composition; and the content of the vegetable oil and/or the fatty acid ester (f) originated from a vegetable oil is 0.1 to 2.5 mass%. <P>COPYRIGHT: (C)2012,JPO&INPIT |
