| 摘要 |
PURPOSE:To enhance color forming capacity, greening resistance and coating workability, by compounding specific natural zeolite with an activated clay type coupler. CONSTITUTION:The title coupler for a leuco dye is obtained by the acid treatment of montmorillonite type clay mineral and formed of a composition having a specific surface area of 180m<2>/g or more and containing activated clay A having a chemical composition wherein a mol ratio of Al2O3/SiO2 is 0.6-0.001 and natural zeolite B in a wt. ratio of A:B=5:95-95:5. Said natural zeolite B has at least one kind of a zeolite crystal structure selected from clinoptilolite and mordenite, a chemical structure wherein a part of the alkali metal component in zeolite is substituted with an alkaline earth metal and/or a multivalent metal such as an iron component and a property such that cation exchange capacity is 100 miliequivalent/100g or more and acidity in a pKa range of +1.5-+4.8 is 0.07 miliequivalent/g or more. |
