| 摘要 |
PURPOSE: An offset printing ink composition is provided to have various properties capable of many-color printing on both sides at once, and to have excellent chemical durability, thereby capable of remarkably reducing damages of an ink layer against chemicals. CONSTITUTION: An offset printing ink composition comprises 5-35 weight% of pigment, 55-85 weight% of rosin modified phenol series varnish, 5-15 weight% of high-viscosity aliphatic solvent, 1-3 weight% of drier, and 0.1-5 weight% of surfactant. The weight average molecular weight of the rosin modified phenol series varnish is 500,000-700,000. The composition additionally comprises rosin modified phenol series varnish of which weight average molecular weight is 150,000-200,000. The content of the varnish of which weight average molecular weight is 150,000-200,000 is 30-60 parts by weight based on 100.0 parts by weight of the varnish of which weight average molecular weight is 500,000-700,000. |
