Abstract: An irreversible thermochromic ink composition can include thermochromic pigment capsules dispersed in a carrier. The irreversible thermochromic pigment capsules can include an inner core having a color changing dye, a color activator for activating the color changing dye, and a wax, an outer core surrounding the inner core and comprising a color destroying agent, and a shell surrounding the outer core. Alternatively, the irreversible thermochromic pigment capsules can include an inner core having a color destroying agent and a wax, an outer core surrounding the inner core and comprising a color changing dye and a color activator for activating the color changing dye, and a shell surrounding the outer core. Written marks made with the irreversible thermochromic inks can be rendered a different color or substantially colorless by application of a sufficient amount of heat to melt or substantially liquefy the wax in the irreversible thermochromic pigment capsules.

Abstract: The disclosure is generally related to an irreversible thermochromic ink composition and, more particularly, to an irreversible thermochromic ink composition comprising a carrier and thermochromic capsules, the thermochromic capsules comprising a shell and a core, the core comprising an eradicable dye capable of becoming substantially colorless and/or of changing color from a first colored state to a second colored state when exposed to an eradicator.

Abstract: An irreversible thermochromic ink composition can include thermochromic pigment capsules dispersed in a carrier. The irreversible thermochromic pigment capsules can include an inner core having a color changing dye, a color activator for activating the color changing dye, and a wax, an outer core surrounding the inner core and comprising a color destroying agent, and a shell surrounding the outer core. Alternatively, the irreversible thermochromic pigment capsules can include an inner core having a color destroying agent and a wax, an outer core surrounding the inner core and comprising a color changing dye and a color activator for activating the color changing dye, and a shell surrounding the outer core. Written marks made with the irreversible thermochromic inks can be rendered a different color or substantially colorless by application of a sufficient amount of heat to melt or substantially liquefy the wax in the irreversible thermochromic pigment capsules.