THERMOCHROMIC COLOR-MEMORIZATION TYPE TONER, CARTRIDGE INCLUDING SAME HOUSED THEREIN, IMAGE FORMATION APPARATUS, CARTRIDGE SET, AND IMAGE FORMATION APPARATUS SET

摘要

The present invention provides a thermochromic color-memory toner having a function that an image formed on a copied matter can be maintained in either in a colored state or a decolored state. A thermochromic color-memory toner containing: at least a microcapsule pigment encapsulating a thermochromic color-memory composition; and a binder resin, in which the microcapsule pigment shows a hysteresis characteristic that, in a temperature-rise process where the pigment is in a colored state, decoloration starts when the temperature reaches temperature t 3 and the pigment completely reaches a decolored state in a temperature region of equal to or higher than temperature t 4 which is higher than temperature t 3 , and, in a temperature-drop process, coloration starts when the temperature reaches temperature t 2 which is lower than temperature t 3 and the pigment completely reaches a colored state in a temperature region of equal to or lower than temperature t 1 which is lower than temperature t 2 , with either the colored state or the decolored state being selectively observed visually in a temperature region between temperature t 2 and temperature t 3 , and the temperature t 1 is in a range of from -50 to 0°C and the temperature t 4 is in a range of from 50 to 150°C; a cartridge including the toner housed therein; an image formation, apparatus; a cartridge set; and an image formation apparatus set.