The main ingredient of the binder is the resin, which is the heart of aqueous ink. Ink viscosity, gloss, water resistance, drying, fluidity, transferability, and fixing properties are mainly determined by the binder. The ink's acid resistance, alkali resistance and solvent resistance are also related to the binder. Therefore, the development of ink painting focuses on the development of ink binders.
The important indicators for the selection of water-soluble resins are molecular weight (Mw) and acid value (AV), among which molecular weight is the most important. With a high solids content of low molecular weight resin, the ink can have a higher gloss, reduce water evaporation, and speed up drying. The high acidity resin has a high re-solubility in the ink and can improve the wettability of the pigment, but it lowers the wet abrasion resistance. The low acid resin has good alkali resistance and detergent resistance, but the pigment has poor dispersibility and resolubility.
Acrylic resin is used as a binder for water-based inks. The inks have significant advantages in terms of gloss, weather resistance, heat resistance, water resistance, chemical resistance, and stain resistance, and can be used to directly disperse dissolved or synthetic polymer emulsions. , also has excellent performance. Therefore, at present, most of the foreign countries use acrylic alkali-soluble resin and modified acrylic resin such as maleic anhydride as the ink film-forming resin.
Source: Chinese ink