In recent years, with the development of building an environment-friendly society and the improvement of people's living standards, the consumption of various packaging materials has increased significantly and become increasingly exquisite, and the demand for waterborne coatings has increased substantially, especially the application of waterborne inks has increased year by year. For example, food packaging, gift packaging, liquid milk inner and outer packaging and so on, all use rosin resin, acrylic resin and water-based polyurethane and other environmental friendly water-based printing ink.           
The rapid development of waterborne coatings and inks has led to the development of waterborne coatings and inks. Defoamer is an indispensable assistant for water-based ink. It plays an important role in eliminating the foam and inhibiting the foaming of water-based ink. The development of water-based ink has led to the increase of defoamer dosage, and put forward higher requirements for the performance of defoamer, mainly including: 1. Fast defoaming ability; 2. Lasting foam suppression ability; 3. Shear resistance and abrasion resistance; 4. Good compatibility with the ink system, which does not cause film shrinkage, orange peel, flower and other surface defects.           
Defoamers used in water-based ink mainly include: (1) traditional defoamers: mineral oil wax, metal soap, etc. Such defoamer has poor compatibility with the emulsion because of its poor compatibility with the emulsion, and its defoaming effect is not good. (2) Polyether block defoamer: this kind of defoamer has excellent compatibility, less paint film surface defects, does not affect the gloss and haze, and is suitable for high surface requirements of ink. (3) organosilicon defoamer: it mainly includes two types of emulsion polysiloxane and polyether modified organosilicon defoamer. This kind of defoamer has excellent antifoaming ability and thermal stability, and is widely used in water-based ink. (4) Compound defoamer: mineral oil / wax / organosilicon, mineral oil / hydrophobic particles / organosilicon, Organosilicon / hydrophobic particles, etc. This kind of defoamer has excellent versatility and compatibility, and less surface defects.