| 摘要 |
PURPOSE:To provide an ink compsn. which readily undergoes chemical change under the action of chlorine-based bleaching agent and loses infrared ray-absorbing property, prepared by adding cyanine type acid dye which shows a specified infrared ray absorption peak. CONSTITUTION:A cyanine type acid dye which shows a peak infrared ray absorption within the range of 700-1,100nm (e.g. monosodium 3,3,3',3'-tetramethyl- 1,1'-di(4-sulfobutyl)-4,5,4',5'-dibenzindotricarbocyanine iodide) is dissolved in 0.5- 20wt% in a solvent consisting of 0-40wt% polyhydric alcohol (e.g. ethylene glycol) or deriv. thereof, 0-30wt% alcohol and 30-95wt% water. The markings made by the ink compsn. loses infrared ray absorbing property and becomes transparent under the action of aqueous soln. of bleaching agent with an effective chlorine content of 0.5-10%. |
