Principle of Waterborne Coating Dispersant

Most of the dispersant achieve the purpose of dispersing the color filler through the process of wetting, grinding and dispersion, coupling and stable packing. However, in the water-based paint, due to the reason of cost controlling , cannot use much more expensive dispersant. Most of the products currently on the market are anionic and non-ionic wetting dispersants. Their principle is that low surface tension, quickly wetting the pigment particles, and then through the high shear force, such as dispersers, grinding machines and other particles to form a semi-flocculent (or called flocculation) dispersion body. If the viscosity of the paint at this time is relatively high, then there will be no paint and coarse flocculation phenomenon, if the viscosity control is not so good, it will be a problem after a long time. Some people use coupling agents as dispersants, couple two different substances together through their hydrophilic groups and sulfur groups, like bridges. It may have many benefits: good comprehensive performance, the ability of being dispersed, the less amount, and can increase the adhesion of paint. But it is also inadequate: it is not a solution flocculation group, so is not suitable for paint with high performance requirements.

    Through research and practice, it is recommended to use a dispersible agent in an aqueous coating. If so, it may have the advantages of good color rendering of paint, high brightness, and good gloss effects. However, in the pure emulsion system, we recommend the use of enhanced charge repellent dispersant, such as an neutral electrically amine salt, a dispersant of a polycarboxylate. Now there are some Polyol Surfactants on the market, people can have a try and find the most suitable product. It is recommended to combine with some polymer dispersant which can react with flocculation, the effect will be better. It is also suggested, when using thickeners, try to use some thickener that does not affect gloss and will not thicken after thickening.