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When introducing the principle of defoamers, the first is incompatibility, and the second is that they have a lower surface tension than the system being used. So all substances that are incompatible with the application system and have lower surface tension than the applied system can be used as defoamers. There are several main categories of defoamers in coatings.

The first type is defoamers for mineral oils, which are composed of white oil, fatty acid esters, waxes, and so on. They are usually low-cost, have average compatibility, and are suitable for non-polar solvent based and water-based systems. Under high shear or high temperature conditions, their stability is relatively poor. It is easy to cause defects such as oil separation and loss of gloss.

The second type is organic silicon based miniaturization agents, which are composed of polydimethylsiloxane and hydrophobic silica, among others. The surface tension is relatively low, the digestion efficiency is very high, and the dosage is very small, usually between 0.05% and 0.5%. It has strong chemical inertness and good heat resistance, making it suitable for difficult to digest resin systems. This type must undergo high-speed dispersion or grinding. If the dispersion is poor, it is likely to cause defects such as shrinkage or fisheye.

The third type is polymer based, polyether based defoamers, composed of polyoxyethylene ether, polyoxypropylene ether, or other block copolymers, with strong foaming ability and slower digestion speed than organosilicon based defoamers. It has good water solubility and is suitable for water-based coatings.

It can control the balance of hydrophilicity and lipophilicity through the ratio of EO and PO, thereby controlling its digestion effect. Relatively speaking, its digestive ability is weaker.

The fourth type is polyether modified polysiloxane defoamers. This type of defoamer combines the hydrophilicity of polyether and the low surface tension of organosilicon, while also achieving efficient defoaming effect and anti foaming ability, with good compatibility. It is also less prone to shrinkage. The most widely used defoamer in water-based industrial paints.

The fifth type is fluorosilicone defoamers, which are mainly modified with multi fluorinated organic compounds and are called fluorosilicone defoamers. Because this type of product has a stronger ability to reduce surface tension than pure silicone defoamers. It can provide stronger defoaming effect or better compatibility. We know that the mechanism of defoaming is to utilize incompatibility and low surface tension. What about fluorosilicone defoamers? Their surface tension is slightly lower, so only a small amount of addition is needed to achieve this excellent defoaming effect. When achieving sufficient defoaming effect, its addition amount is very small and often not enough to cause significant changes in compatibility. So this type of defoamer is often used in highly transparent systems, such as the topcoat varnish of wood paint. The sixth category is other non silicone defoamers. Non silicone defoamers such as polyolefin, polyethylene ether, polyacrylate, and some polyester are widely used in solvent based coatings.

In addition, some limited incompatible leveling or wetting agents also have digestive functions. Our dispersion system achieves complete depolymerization, which also has a beneficial effect on defoaming.