Silibase is one of the leading & professional manufacturers specialized in producing all kinds of SILICONE BASED new materials.
Silibase technique team always focus on quality first and insist on developing new products.
Silibase people will serve you the best before and after sale.
Aug 20, 2021
For a certain formula system, you should choose the appropriate leveling agent according to the properties of the formula and the desired performance of the leveling agent.1, solvent-based coating system In the primer and middle coat formulations, acrylic leveling agents are usually used. If you need degassing and substrate wettability, you should choose medium molecular weight or high molecular weight acrylic leveling agent. In the primer, if stronger substrate wettability is required, you can consider using silicone leveling agents and modified acrylic leveling agents that can significantly reduce surface tension (such as fluorine-modified acrylic leveling agents and phosphate ester modification agents).
Acrylic acid leveling agent). If the side effects of silicone leveling agent and fluorine-modified acrylic leveling agent are stabilizing foam and affecting interlayer adhesion, phosphate modified acrylic leveling agent should be used.In the top coat and clear paint formulations, the appearance of the paint film is relatively high. Generally, a low molecular weight acrylic leveling agent can be used, which will obtain good leveling properties and hardly produce haze in the paint film. In the cross-linking curing system, the selection of acrylic leveling agents containing reactive functional groups often obtains better leveling properties and at the same time improves the physical and chemical properties of the paint film. If the paint film is required to have better fluidity or slip and scratch resistance, silicone leveling agent is necessary. In this case, it is best to use a combination of silicone leveling agent and acrylic leveling agent.It should be pointed out that when applying on a vertical surface, the silicone leveling agent provides leveling performance while effectively reducing the sagging tendency of the coating. In addition, silicone leveling agents should be used with caution in the formulation of metallic flash paints, as they may cause uneven arrangement of flake aluminum pigments and uneven paint film colors.2, powder coating system The leveling process of powder coating is divided into two stages. The first stage is the melting of the powder particles, and the second stage is the melting of the powder particles and flows into a smooth paint film. The powder coating does not contain solvents and does not produce a surface tension gradient during the film formation process.
The leveling is more related to the wetting of the substrate.Powder coatings often use acrylic leveling agents. If the leveling agent is in a liquid state, it must be made into a masterbatch before it can be used. There are also powdered acrylic leveling agents that are specially used for powder coatings. This type of product adsorbs liquid acrylic leveling agents on silica powder, and some low-grade leveling agents are adsorbed by calcium carbonate.If the powder coating needs slippage and scratch resistance, it is necessary to use silicone leveling agent. There are already powdered silicone leveling agents specially used for powder coatings. Care should be taken to avoid the formation of shrinkage cavities when using silicone leveling agents.3. Water-based paint system Water-based paint system is divided into water-soluble system and latex system.In water-soluble systems, it is necessary to strongly reduce the surface tension of the system.
The most commonly used are silicone leveling agents and fluorocarbon compound leveling agents, which have the same effect as they are used in solvent-based coating systems. Of course, if a truly flat surface is required, the acrylic leveling agent for water-based systems is necessary.For latex systems, the film forming mechanism is completely different, and the viscosity does not change with the volatilization of the solvent. The use of a leveling agent in the formulation may improve the wettability of the coating's substrate. Acrylic leveling agent can improve the flatness of the paint film, but the main flow properties of the coating are controlled and adjusted by adding rheology control agents. .