PROCESS OF PREPARATION OF AN AQUEOUS GEL INK WITH FIXED COLOR COMPRISING SILVER NANOPARTICLES

摘要

The present invention concerns a process for preparing an aqueous gel ink with fixed color comprising the following steps: (i) preparing a gel-based matrix of aqueous ink; (ii) preparing an aqueous suspension of silver nanoparticles with a fixed color by mixing silver salts with: - water, - a mixture of at least an alkali metal or alkaline earth metal salt of citrate, - an oxidizing agent, preferably hydrogen peroxide H₂O₂, - and polyvinylpyrrolidone; (iii) adding under agitation the aqueous suspension of silver nanoparticles obtained in step (ii) to the gel-based matrix of aqueous ink obtained in step (i), to obtain an aqueous gel ink with fixed color with silver nanoparticles dispersed therein.