Reversibly allochroic toner, method of producing the same, toner cartridge, and image forming apparatus

A toner cartridge comprising a toner that includes a binder resin and a colorant,

• wherein the colorant reversibly switches between a first color state and a second color state in response to a temperature change, and the colorant exhibits a hysteresis in a temperature-color state curve thereof such that,
• when the colorant is in the first color state, and the temperature keeps increasing, when the temperature reaches a temperature TH1 (° C.), the colorant starts to change from the first color state to the second color state, and in a temperature region in which the temperature is equal to or higher than a temperature TH2 (° C.) which is higher than the temperature TH1 (° C.), the colorant reversibly switches to the second color state,
• when the colorant is in the second color state, and the temperature keeps decreasing, when the temperature reaches a temperature TL1 (° C.), the colorant starts to change from the second color state to the first color state, and in a temperature region in which the temperature is equal to or lower than a temperature TL2 (° C.) which is lower than the temperature TL1 (° C.), the colorant reversibly switches to the first color state, and
• the relationship of the following Formula is satisfied,
• TH2<Tg, wherein Tg indicates a glass transition temperature (° C.) of the binder resin,
• TH2<50° C.,
• TH1−TL1≤7° C., and
• TL2 is greater than 20° C.