US 12,139,626 B2
Irreversibly erasable ink composition having a discoloration agent
Aurore Sauvage, Gy-les-Nonains (FR); and Guillaume Caffier, Wegscheid (FR)
Assigned to Société BIC, Clichy (FR)
Filed by Société BIC, Clichy (FR)
Filed on Dec. 22, 2020, as Appl. No. 17/130,528.
Claims priority of application No. 20000039 (EP), filed on Jan. 28, 2020; and application No. 20315020 (EP), filed on Feb. 14, 2020.
Prior Publication US 2021/0230440 A1, Jul. 29, 2021
Int. Cl. C09D 11/50 (2014.01); C08K 5/17 (2006.01); C08L 101/00 (2006.01); C09D 11/17 (2014.01); C09D 11/18 (2006.01)
CPC C09D 11/50 (2013.01) [C08K 5/17 (2013.01); C08L 101/00 (2013.01); C09D 11/17 (2013.01); C09D 11/18 (2013.01); C08L 2207/53 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A thermochromic ink composition comprising core-shell microcapsules, an aqueous dispersion medium and a decolorization agent,
wherein the core-shell microcapsules comprise a core component and a shell component, wherein the core component comprises (a) an electron-donative organic compound, (b) an electron-accepting compound, and (c) a reaction medium for causing a color-forming electron transfer reaction between the components (a) and (b) above the melting or softening point of the core component, wherein the shell component encapsulates the core component, and wherein the shell component comprises an organic polymer;
wherein the decolorization agent is dissolved or dispersed in the aqueous dispersion medium;
wherein the decolorization agent is capable of irreversibly decoloring a colorant formed by the electron transfer reaction between the components (a) and (b); wherein the decolorization agent is a polyether amine comprising a polyether backbone comprising one or more primary amino groups attached to the end of the polyether backbone, and wherein the polyether backbone further comprises repeat units formed from ethylene oxide or propylene oxide or mixtures thereof; and wherein the decolorization agent has a weight-average molecular weight of more than 270 g/mol and less than 2000 g/mol.