| 摘要 |
PURPOSE:To prevent the staining of a hand, a face, clothes, furniture, etc., due to an ink by printing with a colorless, transparent ink which develops color by the reaction with a printing paper previously coated with a color- developing agent and dried. CONSTITUTION:A colorless, transparent ink is prepd. by dissolving 1-10 pts.wt. leuco dye and necessary amts. of a thickener, an oil, a plasticizer, a desensitizing agent, etc., in 100 pts.wt. dye solvent. A color-developing agent soln. is prepd. by dissolving 1-10 pts.wt. color-developing agent selected from the group consisting of a phenol compd., a solid inorg. acid, and an acidic substance in 100 pts.wt. solvent. A printing paper is coated with the developing agent soln. in such a manner that the wt. ratio of the agent to the dye is 0.2-30 and dried. This coated paper is printed with the ink, causing the dye to react with the agent to develop color. |
