TEMPERATURE-SENSITIVELY COLOR-CHANGING COLOR-MEMORIZING INK COMPOSITION FOR WRITING UTENSIL

摘要

PROBLEM TO BE SOLVED: To obtain an ink composition for a writing utensil, reversibly changing the color while exhibiting a wide hysteresis width in a color density-temperature curve, and effectively exhibiting characteristics of tautomatically memorizing and holding both of a color at the lower temperature side of the color-changing temperature and a color at the higher temperature side.;SOLUTION: The temperature-sensitively color-changing color-memorizing ink composition for the writing utensil comprises at least a microcapsule pigment including a temperature-sensitively color-changing color-memorizing composition comprising a homogeneous compatibilized product of (a) an electron-donating coloring organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of the component (a) with (b), and a solvent. The microcapsule pigment exhibits 40-70°C hysteresis width (ΔH) in the color density-temperature curve, and has ≥45°C complete decolorizing temperature (T₄) and ≤0°C decolorization-holding temperature (T₂).;COPYRIGHT: (C)2006,JPO&NCIPI