| 摘要 |
PURPOSE:To provide an erasable coloring agent composition composed of an electron-donative organic compound, a p-hydroxybenzoic acid ester and an organic solvent, developing clear color by the evaporation of the solvent, completely losing the color after a specific period and suitable for a writing ink, etc. CONSTITUTION:The objective erasable coloring agent composition can be produced by mixing (A) preferably 0.5-5.0pts.wt. color-developing agent consisting of an electron donative organic compound [preferably a compound of formula (R1-R6 are H, hydroxyl, etc.)] with (B) preferably 1.0-5.0pts. of a color- developer consisting of one or more compounds selected from a p- hydroxybenzoic acid ester (e.g. methyl p-hydroxybenzoate) and a thiourea compound (e.g. thiourea) and (C) preferably 90-98pts. of an organic solvent (e.g. N-propane). |
