News
How to improve the dispersion and stability of carbon black in coatings
2024-05-13 16:00:49
As an important inorganic black pigment, carbon black has been widely used in the coating industry because of its high specific surface area, excellent adsorption capacity and pigment characteristics. However, the dispersibility and stability of carbon black have always been the key factors restricting its performance. This paper will discuss the application status of carbon black in coatings, the performance of dispersion problems, the influence of stability problems and solutions.
Application status of carbon black in coatings
Carbon black is often used in coatings as a dispersant, colorizer and preservative for black and dark color pasts. Its fine particle size and uniform dispersion make carbon black have significant advantages in blackness, hiding rate and coloring power of coatings. However, the high surface area and hydropathy of carbon black lead to its dispersibility and stability problems in coatings, which affect the quality and performance of products.
Dispersion of carbon black
The dispersibility of carbon black mainly shows agglomeration and sedimentation. The strong cohesion between carbon black particles makes the carbon black powder easy to agglomerate, resulting in uneven pigment dispersion and affecting the gloss and color of the coating. The specific performance is as follows:
Insufficient color coloring intensity: the blackness of the pigment carbon black cannot be fully displayed, and the color is not good.
Uneven distribution: uneven distribution of carbon black paste, coating process of paint film surface stripes or grain sense.
Increase the difficulty of production: poor dispersion of carbon black slurry viscosity is too high, easy to block the net, long production cycle, and even wear grinding machinery.
Influence of carbon black stability problem
The stability of carbon black mainly includes surface activity, thermal stability and oxidation resistance. The low surface activity of carbon black will affect its combination with other components in the coating system and reduce the performance of the coating.
In addition, carbon black is prone to change under high temperature and oxidation environment, resulting in product quality degradation. Especially in coatings, UV rays are the main factor leading to problems such as color change, hardening, and fading. The UV stability of carbon black in coatings, such as color leaching, will seriously affect the appearance quality and durability of the coatings.
Solutions
In order to improve the dispersion and stability of carbon black in coatings, the following measures can be taken:
Select the appropriate carbon black type: according to the specific requirements of the coating, select the appropriate carbon black type, such as surface modified carbon black and nano carbon black, etc., to improve its dispersion and stability.
Optimization formulation design: through rational formulation design, addition of dispersants and stabilizers and other auxiliary agents, improve the dispersion and stability of carbon black.
Improve the production process: control the preparation and addition process of carbon black to avoid the adverse effect of high shear force and temperature on the dispersion and stability of carbon black.
Strengthen quality control: establish a perfect quality control system, strictly test and screen carbon black to ensure the stability of product quality.
Surface modification technology: The surface modification technology of carbon black, such as surface oxidation modification, is studied to improve the water dispersibility and stability of carbon black by introducing oxygen-containing groups.
Add ultraviolet stabilizer: add appropriate ultraviolet stabilizer in the coating, reduce the damage of ultraviolet on carbon black and coating system, improve the weather resistance and ultraviolet stability of the coating.
Conclusion
The dispersibility and stability of carbon black in coatings is one of the hotspots and difficulties in current research. The dispersibility and stability of carbon black can be effectively improved by reasonable selection of carbon black types, optimization of formula design, improvement of production technology and strengthening of quality control.
Future research should focus on the interaction mechanism between carbon black and dispersants and the modification technology of carbon black, in order to realize the efficient application of carbon black in coatings and the improvement of product quality.
With the continuous progress of technology and research, the application prospect of carbon black in the coating industry will be more broad.