| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ink composition for waterless offset printing free from the generation of scumming upon substitution with vegetable oil without using a petroleum-based solvent having a scumming suppression effect for corresponding to an environmental problem. <P>SOLUTION: The ink composition for waterless offset printing includes a colorant, a binder resin, and a vegetable oil component, and does not include a mineral oil component. The binder resin includes a carboxyl group(s) and/or a hydroxyl group(s) in the molecule, and also, the following conditions 1, 2 are satisfied: the condition 1 wherein, when the acid value based on the carboxyl group(s) of the binder resin is defined as Av(mgKOH/g) and hydroxyl group value is defied as OHV(mgKOH/g), hydrophilic group number (2.1×AV+1.9×OHV) introduced using the HLB group number of the carboxyl group(s) and hydroxyl group(s) by DAVIES (carboxyl group(s)=2.1, hydroxyl group(s)=1.9) satisfies the following formula 1, 2.1×AV+1.9×OHV≥180 (formula 1); and the condition 2 wherein, when 35 pts.mass of the binder resin is added to 65 pts.mass of soybean oil to be heated and molten at 170°C and then cooling is performed to 25°C, the precipitation of the binder resin does not occur, and the state of a transparent resin solution is retained. <P>COPYRIGHT: (C)2013,JPO&INPIT |
