CONCRETE COLORING MATERIAL

摘要

PURPOSE:To obtain a concrete coloring material colorless before applying on a cement and color-developed after applying by incorporating a leuco dye color- developed from colorless to colored by allowing to react with a hydrate cement. CONSTITUTION:A material having a structure expressed by e.g. formula I such as a group composed of fluorane, phthalide and spiropyrane-based compounds which is color-developed by acid and being colorless but color-developed into black by ionizing a ring such as lactone ring by the electron transfer by bringing it into contact with acid thereby forming a quinoid structure or a resonance structure to change to a structure expressed by formula II and a material having a structure expressed by formula III such as a group composed of phenothiazine, phenoxazine and triphenylmethane-based compounds which is color-developed by oxidation, and being colorless but color developed into blue by air-oxidizing to change to a structure expressed by formula V are used in combination as the leuco dye. The dye is color-developed only at the time of applying on a concrete containing a solid acid and is colorless even in sticking to the other building material.