| 摘要 |
PURPOSE:To obtain the subject indicator ink having excellent moisture resistance and resistant to color fading even if left standing in a hot humid state after being discolored with electron ray by dissolving a specific color dye, a polymer substance containing a specific amount of chlorine and a bisphenol compound in an organic solvent. CONSTITUTION:The objective ink suitable for the printing of a letter, mark, etc., changing its color by the irradiation of electron ray to indicate the previous electron irradiation event is produced by dissolving (A) a color dye changing its color by pH variation, preferably methyl yellow of formula (R1 is 1-4C lower alkyl), etc., (B) a polymer substance containing >=35wt.% of chlorine in the molecule such as vinyl chloride resin and (C) a bisphenol compound such as 2, 2-bis(4-hydroxyphenyl) propane in (D) an organic solvent such as tetrahydrofuran. |
