AQUEOUS FLUORESCENT INK, RECORDED IMAGE USING SAME, AND JUDGING METHOD

摘要

An aqueous fluorescent ink containing water, a colorant and an organic solvent the latter two soluble or dispersible in water, and used for measuring/judging fluorescence in a visible region with an exciting wavelength in a predetermined ultraviolet region, characterized in that the colorant has a colorant structure having fluorophores, and a water-soluble colorant having a sulfonic group as a water-soluble group in a free acid form is used. The water resistance and light fastness are favorable. The content of the fluorescent colorant in ink can be greatly increased though conventionally only a small amount of fluorescent colorant can be contained because of the concentration quenching problem. The fluorescence is excellent and the recorded image has an excellent water resistance. The resistance of the colorant to fixing to the recording medium and the reliability are also excellent.