| 摘要 |
This invention provides a bank note marking agent constituted by a water soluble dye that is adapted to be rendered water insoluble when brought into contact with water or an organic solvent. Alternatively or in addition, the bank note marking agent may be constituted by a marking substance, such as cobalt nitrate, that is adapted to produce a colour when exposed to an oxidizing agent, such as a bleaching agent. The bank note marking agent is preferably adapted for use in a cash in transit box. The dye of this marking agent is preferably constituted by a quaternary dye salt, the preferred salt being a quaternary of pthalo cyanine blue and a suitable nitrogen containing compound such as acetylated pyrrolidone, produced by reacting pyrrolidone with acetic acid in the presence of an acid catalyst to produce the acetylated pyrrolidone, whereafter the acetylated pyrrolidone is reacted with the pthalo cyanine blue in the presence of a pH reducing agent such a methylethanolamine to produce the salt. |
