| 摘要 |
PROBLEM TO BE SOLVED: To provide a porous fine particle which does not cause nozzle clogging when used as an ink component and exerts an excellent heat stability, water resistance and weatherability. SOLUTION: This porous fine particle has an amino group-substituted hydrocarbon group at its pore surface and occludes a dye. Here, occlusion represents a state wherein the dye is not only chemically or physically adsorbed by an organic group such as an amino group, etc., but is also retained inside the porous fine particle by its affinity for the amino group, etc. The fine particle has an average particle size of from 5 to 300 nm, comprises silica and an inorganic oxide other than silica and has a molar ratio MOx/SiO2, provided that silica is SiO2 and the inorganic oxide other than silica is MOx, of from 0.0001 to 0.2. The amount of amino groups in 1 g fine particle is from 1 to 15 mmol, and the amount of the dye occluded is from 0.017 to 0.5 g. An ink contains from 1 to 30 wt.% porous fine particle. |
