Thixotropic Modulating Oil Formulation and Development (5)

4.5 thickener

The thickening effects of the four organic thickeners on the same varnish system are shown in Table 3.

The thixotropy caused by paraffin wax, chlorinated paraffin, and metal stearic acid soap disappeared after being left for 1 d. The thixotropy produced by stearic acid glycerin did not disappear after 1 d or even 1 year. When the amount of stearic acid glyceride is 4% to 12% of the amount of the resin solution, it can meet the requirements of different cost thixotropic varnish (Table 4).

5 Application

Mix 70 parts of thixotropic varnish and 100 parts of pigment into the printing ink. Use a 350 mesh/100 thread nylon screen printing on the cylinder printing machine. Even if printing 500 pieces, there is no plug hole and dot reproducibility is good. The decals were wet-laid onto the white ceramics, dried, and calcined at 800°C to give crease-free, airless, and plastic-free patterns.

The thixotropic varnish was tested on the Tangshan Flower Paper Factory's Japan 72A screen printing machine, and the results were good, which is in line with the plant's technical standards. In the Jingdezhen porcelain flower screen printing machine imported from Japan on the screen printing machine trial, the effect is also good. The drying performance meets the 40°C oven drying requirements and meets the plant's technical requirements.

6 Conclusion

Acrylic acid copolymer was prepared by a solution polymerization method. As a film forming material of a varnish, a thixotropic varnish was prepared by adding a thickener, a plasticizer, a defoamer, and a solvent, etc., having good thixotropy and pigment dispersion. Sex and printability, etc., can be used in ceramic, enamel and glass industry printing. The varnish is suitable for 350 mesh/100 line screen printing, and the product pattern is clear.

Source: Printing Chemicals