Water Based Wetting Agents Should Pay Attention To These Aspects During The Production Process

In order to achieve better results of water-based wetting agents in the production process of water-based coatings, attention must be paid to the following aspects.
1. Compatibility between waterborne wetting agents and resins
The resin and dispersant must have good compatibility. Especially for polymer dispersants, if their compatibility is poor, the extended chain segments of the polymer dispersant will not stretch well in the dispersion medium, curl around the pigment particles, reduce the thickness of the adsorption layer, decrease the spatial hindrance, and have poor stability. In severe cases, it can affect the gloss, coloring power, brightness, developing ability, adhesion and other properties. Therefore, compatibility must be tested first to avoid any issues.

2. Properties of resin
The properties of resins are also closely related to the application of dispersants. For example, alkyd resins with medium to long oil content contain more active groups and have strong wetting and adsorption abilities. It can be used normally without adding wetting dispersant or with a small amount. However, some resins, such as thermoplastic acrylic resin and vinyl resin, do not contain or have almost no active groups, and have poor wetting and adsorption abilities. When dispersing pigments, a wetting dispersant must be added. Therefore, when using wetting dispersants, the selection should be based on the properties of the resin.

3. Surface characteristics of pigments
When dispersing pigments, the first thing to pay attention to is the type of pigment, whether it is organic or inorganic. Attention should also be paid to the surface characteristics of pigments, especially inorganic pigments. It is important to know whether the surface has acidic, alkaline, or acidic and alkaline centers. Then select the ion type based on the acidity and alkalinity of the low molecular surfactant. Most organic pigments use high molecular weight wetting dispersants. Pay attention to the affinity between the anchoring group of the dispersant and the pigment, so that it can form a strong adsorption layer on the surface of the pigment.

4. The amount of wetting dispersant added
When providing auxiliary samples, there may be suggested dosage, but the dosage is only rough and the accuracy is poor. When using, a comprehensive, systematic, and accurate experiment must be conducted based on the above situation and formula design requirements to determine the amount of addition. quantity The specific surface area of pigments and the fineness of dispersions should be used as reference conditions for the amount of dispersant added. The larger the specific surface area, the smaller the dispersion fineness, and more dispersants should be added. There are many methods to determine the amount of pigment added, and regardless of which method needs to be tested in practice, the stability of pigment dispersion and the effect of dispersant addition can be determined through thermal storage or room temperature storage.