| 摘要 |
PURPOSE:To prepare ink capable of accurately detecting O2 during use, by a method wherein a solution A formed by adding a thiazine dye to a water or an alcohol soluble resin-containing solution and a solution B having a reducing agent added thereto are separately preserved to be made preservable for a long period of time and both solutions A, B are mixed in use. CONSTITUTION:A thiazine dye such as methylene blue and a reducing agent such as ascorbic acid are added to water or a solution containing alcohol soluble resin to be dissolved or dispersed therein to obtain an ink composition for detecting O2. The discoloration of this ink composition can be accerelated by adding an inorg. porous fine powder such as SiO2 or CaSiO3 to said ink compositon to promote the contact with oxygen. This ink composition is lowered in the detecting capacity thereof when a longtime is elapsed after preparation because of the coexistence of the reducing agent and, therefore, the resin solution containing the dye and the resin solution containing the reducing agnet are separately preserved to be made preservable for a long period of time. When food packing paper is printed with this ink composition, the diterioration of content due to oxygen can be detected by color change due to oxygen. |
