Detailed explanation of the wetting principle of water-based wetting agents

1. The concept of wetting agent:

The basic characteristic of the molecular structure of a wetting agent is that one end of the molecule has a hydrophilic group (segment) and the other end has a hydrophobic group (segment) Chemical material. In layman’s terms, it is a type of chemical substance whose molecules are hydrophilic and hydrophobic respectively.

Let’s take water-based wetting agents as an example to share the wetting principle of water-based wetting agents:

When a water-based resin is coated on the surface of a substrate, part of the wetting agent is at the bottom of the coating. It contacts the wetted surface and is lipophilic. The chain segments are adsorbed on the solid surface, and the hydrophilic groups extend outward toward the water. The contact between water and the substrate is changed to the contact between water and the hydrophilic group of the wetting agent, forming a sandwich structure with the wetting agent as the middle layer. Make the water phase spread more easily, thereby achieving the purpose of wetting.

2. Types of wetting agents

Divided according to chemical structure, the wetting agents currently on the market mainly include: silicone, anionic, nonionic, etc. Among them, the silicone wetting agents mainly include polyether-modified silicones, the anionic wetting agents mainly include ethylene oxide adducts, and the nonionic wetting agents mainly include fluorine polymers.

According to the wetting object, it can be divided into: Substrate wetting type, wetting leveling agent and wetting and dispersing agent, etc.

3. Evaluation of the effectiveness of water-based wetting agents

We can know that the stronger the wetting ability, the better it spreads. In the actual production and R&D process, we take the same volume of water-based resin, add the same amount of wetting agent, and prepare a water-based resin system with the same wetting agent, and then coat it on the same substrate and measure the final spread. Area, the wetting ability of the wetting agent is judged based on the size of the spreading area.