Patent ID: 8187373
Filing Date: 2012-05-29
Classification: C09B,C09D

Abstract:
1. A printing ink for letterpress and/or offset printing, comprising 5 to 45% by weight of at least one nonpolar solvent with a boiling point of from 200 to 320° C., 20 to 70% by weight of binder, 5 to 25% by weight of colorant absorbing in the visible spectral range and an NIR absorber which has substantially no absorption in the visible spectral range, wherein the solubility of the NIR absorber in the printing ink is at least 0.1% by weight, based on all components of the printing ink, with the proviso that the solubility of the NIR absorber is greater than or equal to the concentration of the NIR absorber in the printing ink, wherein the NIR absorber is an ionic absorber comprising a cyanine cation X + and a corresponding anion 1/mY m− , the cyanine cation having a general formula selected from the group consisting of (I) to (IV) where n is 1 or 2 and the radicals R and the anion Y or the anion Y where R in the radicals R