Process of preparation of an aqueous gel ink with variable color comprising silver nanoparticles
US12202989B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 28, 2020 |
| Grant date | Jan 21, 2025 |
| Priority date | — |
| Expiry date | May 7, 2042 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D11/50
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention concerns a process for preparing in situ an aqueous gel ink with variable color comprising the following steps: (i) preparing a gel-based matrix of aqueous ink comprising 0.005 to 0.1 mol·L−1 of ester(s) of retinol represented by formula (I), and (ii) adding a solution of 0.002 to 0.05 mol·L−1 silver salts (Ag+) to the gel-based matrix of aqueous ink prepared in step (i), to obtain an aqueous gel ink with variable color with silver nanoparticles dispersed therein. The present invention also relates to an aqueous gel ink with variable color obtained according to the process of the invention, comprising said ester of retinol represented by formula (I) and silver nanoparticles. The invention finally concerns a writing instrument comprising an aqueous gel ink with variable color according to the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.