The solvent depends on the ability of the plastic to dissolve

The solvent in the ink must be able to dissolve the resin and have a slightly soluble and coarse effect on the surface of the substrate. The solvent's ability to dissolve the plastic depends on the following three factors.

(1) solvation - acidity. It means that in the process of dissolving solutes, the force between the solvent and the solute molecules is greater than the cohesion between the solute molecules, so that the solute molecules can be separated from each other and dissolved in the solvent, ie, the solute and the solvent are different in the acid or basic genes. . For example, PVC is an acid gene and cyclohexanone is a basic gene. There is solvation between them.

(2) The effect of the degree of hydrogen bonding on miscibility. The solvent itself has strength and weakness. Only when the polarities are similar and the hydrogen bonds are similar, the solvents can be dissolved. From Table 2, we can see that the solubility parameters of PP and ethyl acetate are similar, but cannot be mutually soluble, which is due to the strong polarity of PP. Ethyl acetate is polar.

(3) Solubility parameters. In most cases, if the solubility parameter of a certain solvent and a certain polymer (solute) is exactly within a range, the polymer can be dissolved. If two or more solvents are organically combined together, the solubility is greater than Any solvent.

Solvents can be divided into active solvents, inert solvents and diluents. The active solvent can make the resin get the best dissolving, and the inert solvent and diluent can control and change the viscosity, volatilization speed, etc. of the ink, so that the ink adheres to the substrate and achieves the best effect.



Source: China Washing & Dyeing Industry Information Center