Degussa Matting Powder OK520 is an easy-to-disperse, organically treated matting agent suitable for a wide range of applications. Its particle size is 3 microns. In addition, Degussa matting powder OK520 has a high transparency in the matting process of varnishes due to its specially designed precipitation process. Degussa Matting Powder OK520 provides high chemical resistance. It has high matting efficiency; smooth surface feel; good stability performance.
Brand Model: Degussa Matting Powder OK520
Place of origin: Germany
Package specification: 10KG/pack
The reasons for the slow wetting of pigments are:
a. Diffusion pressure is very small (high interfacial tension, such as hydrophobic pigments dispersed in water).
b. The porosity in the pigment agglomerates is small and long (fine particles filled with high-density pigment particles).
c. The viscosity of the base material is high (contrary to the dispersion speed, strong shear stress can be obtained under high viscosity, which can improve the dispersion rate).
3. The effect of wetting and dispersing agent on wetting
When the pigment and resin are selected, the formula is basically fixed. In order to improve the wetting effect, there are almost no variable factors except viscosity, but the reduction of viscosity is also limited. Therefore, the best way to improve the wetting efficiency is to use a wetting and dispersing agent, which will adsorb on the surface of the pigment, reduce the interfacial tension between the pigment and the vehicle, best wax additive reduce the contact angle, and improve the wetting efficiency. For example, when SiO a is dispersed in a rosin-modified polymer aqueous solution, the contact angle is 150°. Adding 0.3% surfactant, the contact angle is reduced to 30°. It can be seen from formula (2-4) and formula (2-5) that the wetting efficiency is improved after adding wetting and dispersing agent. The coating is a heterogeneous dispersion, and the interfacial relationship is quite complicated, and competitive adsorption may occur on the surface of the pigment. When choosing a wetting and dispersing agent, pay attention to its relationship with various materials such as pigments, resins, and solvents. Careful work is required to obtain good results.
Section 3 Basic Principles of Stability of Dispersed System
After the dispersion system is made, the towel will undergo many changes under the influence of gravity, thermodynamics and many other factors.
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