CPC C09D 11/17 (2013.01) [B41J 2/2107 (2013.01); C09D 11/30 (2013.01); C09D 11/32 (2013.01); C09D 11/328 (2013.01); B82Y 40/00 (2013.01)] | 19 Claims |
1. A process for preparing in situ an aqueous gel ink with fixed color comprising the following steps:
(i) preparing a gel-based matrix of aqueous ink comprising 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid as a reducing agent, and
(ii) adding a solution of metallic salts to the gel-based matrix of aqueous ink prepared in step (i), to obtain an aqueous gel ink with fixed color with metallic nanoparticles dispersed therein,
wherein the process is free of addition of a dye or pigment other than metallic nanoparticles.
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