US 12,486,413 B2
Process of preparation of an aqueous gel ink with fixed color comprising silver nanoparticles
Olivier Albenge, Clichy (FR); Romain Metillon, Clichy (FR); Karine Mougin, Paris (FR); Feriel Ghellal, Clichy (FR); and Arnaud Spangenberg, Mulhouse (FR)
Assigned to SOCIÉTÉ BIC, Clichy (FR); UNIVERSITÉ DE HAUTE-ALSACE, Mulhouse (FR); and CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE, Paris (FR)
Appl. No. 17/632,155
Filed by SOCIETE BIC, Clichy (FR); UNIVERSITE DE HAUTE ALSACE, Mulhouse (FR); and CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE, Paris (FR)
PCT Filed Aug. 28, 2020, PCT No. PCT/EP2020/074156
§ 371(c)(1), (2) Date Feb. 1, 2022,
PCT Pub. No. WO2021/038087, PCT Pub. Date Mar. 4, 2021.
Claims priority of application No. 19306050 (EP), filed on Aug. 29, 2019.
Prior Publication US 2022/0275230 A1, Sep. 1, 2022
Int. Cl. C09D 11/00 (2014.01); C09D 11/17 (2014.01)
CPC C09D 11/17 (2013.01) 12 Claims
 
1. A process for preparing an aqueous gel ink with fixed color comprising:
(i) preparing a gel-based matrix of aqueous ink;
(ii) preparing an aqueous suspension of silver nanoparticles with fixed color by mixing silver salts with:
water,
a mixture of at least an alkali metal or alkaline earth metal salt of citrate, and an alkali metal hydride,
a further reducing agent, wherein said further reducing agent is ascorbic acid and/or an amount of the further reducing agent that is added ranges from 0.002 weight % to 0.01 weight %, based on a total weight of the aqueous suspension of silver nanoparticles, and
an oxidizing agent; and
(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.