A kind of water-changing and non-diffusion ink and its preparation method and application

Abstract

The invention relates to the technical field of printing ink and in particular to printing ink capable of discoloring when encountering water and being indiffusible as well as a preparation method andapplication of the printing ink. The printing ink capable of discoloring when encountering the water is prepared from the following raw materials including waterborne film-forming resin, strong-acidand weak-alkali metal salt, a pH indicator with charges, high molecular adsorption resin and a solvent; and the solvent is water or mixed liquid of the water and an organic solvent. In the raw materials of the printing ink, the pH indicator with the charges are chelated with the metal salt to form macromolecules with the charges, and then the macromolecules with the charges are adsorbed by the high molecular adsorption resin, so that although the water exists in the solvent, the pH indicator cannot lose efficacy. After printing, and the printing ink is subjected to temperature drying, a chelate of the pH indicator with the charges and the metal salt is combined with the waterborne film-forming resin, and the pH indicator is adsorbed to the surface of the high molecular resin; and after thehigh molecular adsorption resin absorbs moisture, a microstate acid-alkali value of a printing ink layer is shown to be a pH value of functional groups of the waterborne film-forming resin, and the pH indicator displays a color according to the pH value.

Description

technical field

[0001] The invention relates to the technical field of inks, in particular to an ink that changes color when exposed to water and does not diffuse, as well as its preparation method and application. Background technique

[0002] One of the traditional water-changing inks is a pure organic solvent-based microcapsule system, but the organic solvent of this pure organic solvent-based microcapsule system ink is easy to volatilize, which will cause poor construction environment, pollute the environment, and is not conducive to environmental protection , will also cause certain harm to the user; another indicator that is sensitive to humidity will cause its own color to change when stored in a humid environment, resulting in the failure of the color change indicator, and its practical application is limited. Contents of the invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, one of the purposes of the present invention is t...