COLORLESS SOL-GEL INK FOR INK-JET PRINTING IRIDESCENT HOLOGRAPHIC IMAGES AND METHOD FOR PRODUCING THEREOF Russian patent published in 2018 - IPC C09D11/30 C09D11/322 C09D11/328 C09D11/50 C01G23/47 B82B3/00 

FIELD: polygraphic industry.

SUBSTANCE: invention relates to sol-gel ink for ink-jet printing of iridescent holographic images on holographic paper or on a micro-embossed surface. Sol-gel ink comprises a nanocrystalline titanium dioxide sol of an anatase phase with an amorphous phase content of not more than 5 wt% in water and 60-70 wt% of ethyl alcohol. Solid content of said titanium dioxide sol in the ink is 1-5 wt%. Sol-gel ink has a surface tension of at least 25 mN/m, not more than 50 mN/m and a viscosity of not less than 2.1 mPa⋅s, not more than 20 mPa⋅s. Sol-gel ink is produced in two stages. At the first stage, the nanocrystalline titanium dioxide sol is obtained in water using a solution of titanium isopropoxide and 2-propanol, crystal formation and protonation. At the second stage, the sol-gel ink in the form of a nanocrystalline titanium dioxide sol in a solution of ethyl alcohol in water with the viscosity and surface tension required for ink-jet printing is produced from the nanocrystalline titanium dioxide sol in water.

EFFECT: invention provides a non-toxic ink based on chemically inert and environmentally safe titanium dioxide and environmentally acceptable ethyl alcohol and the possibility of a technologically simple and quick (no more than 5 minutes) ink-jet printing by conventional ink-jet printers unique and individual color iridescent holographic images on micro-embossed or holographic paper.

5 cl, 8 dwg, 1 tbl