Evaluation And Usage Experience Of Water-based Wetting Agents

The basic characteristic of the molecular structure of wetting agents is that one end of the molecule contains a hydrophilic group (chain segment), and the other end contains a hydrophobic group (chain segment) of a chemical substance. Simply put, a type of chemical substance in which molecules have hydrophilicity and hydrophobicity, respectively.
Taking water-based wetting agents as an example, we will share with you the wetting principle of water-based wetting agents:
When water-based resin is coated on the surface of the substrate, a portion of the wetting agent is at the bottom of the coating, in contact with the wetting surface. The hydrophilic chain segments adsorb on the solid surface, and the hydrophilic groups extend outward into the water. The contact between water and substrate becomes the contact between water and hydrophilic groups of wetting agents, forming a sandwich structure with wetting agents as the intermediate layer. Make the aqueous phase easier to spread, thereby achieving the purpose of wetting.
Another part of the water-based wetting agent exists on the surface of the liquid. Its hydrophilic groups extend into liquid water, while hydrophobic groups are exposed to air to form a single-molecule layer, reducing the surface tension of the coating and promoting better wetting of the coating. The substrate is used to achieve the purpose of wetting.

1. Types of wetting agents
According to the chemical structure, the current wetting agents on the market mainly include organic silicon, anionic, non-ionic, etc. Among them, organic silicon wetting agents mainly include polyether modified organic silicon, anionic wetting agents mainly include epoxyethane adducts, and non-ionic wetting agents mainly include: ionic wetting agents mainly include fluoropolymers.
According to the object of wetting, it can be divided into substrate wetting type, wetting leveling agent, and wetting dispersant.

2. Evaluation of the effectiveness of water-based wetting agents
We can know that the stronger the wetting ability, the better the spreading ability. In the actual production and research and development process, we take an equal volume of water-based resin, add an equal amount of wetting agent, prepare the same water-based resin system with the same wetting agent, and then apply it to the same substrate to measure the final spreading area. The wetting ability of the wetting agent is determined based on the size of the spreading area.

3. Experience in using water-based wetting agents
In actual production, when considering the wetting ability of resin, not only static surface tension but also dynamic surface tension need to be considered, because the resin is in a stress state during the coating process. The lower the dynamic surface tension, the better the wettability. At this point, the faster the wetting agent forms a single-molecule layer on the coating surface, that is, the faster the oriented molecular layer forms, which is more conducive to wetting. Fluorine containing wetting agents mainly reduce static surface tension, while organic silicon wetting agents can effectively reduce dynamic surface tension; Therefore, in practical applications, it is very important to choose the appropriate wetting agent according to the actual situation.