The most important influence on the dispersion performance in rubber is the particle size of carbon black.

One of the measures that carbon black manufacturers use to maximize the performance of materials is to disperse the most raw materials into the rubber. The dispersion properties of carbon black in rubber are most affected by the particle size. Theoretically, when carbon black particles are dispersed into rubber to achieve the most homogenization, the carbon black-rubber network formed is the most dense and strong, but in fact, this ideal state is difficult to achieve, especially two or more kinds of carbon. When black is used together, it increases the difficulty of the most uniformity.

Small particle size carbon black (below 30nm) such as high wear resistance, medium super wear resistant black cat rubber special carbon black due to the cohesive force, under normal circumstances, it is difficult to exist in the form of a single particle, even after using ultrasonic treatment, after Under the electron microscope magnified 100,000 times, it is still observed that the particles adhere to each other, crowded together, and the boundary is blurred, and it is difficult to find the particles that exist alone. From this point of view, a sufficiently small particle size of carbon black imparts a strong internal adsorption energy to the carbon black and a poor wetting ability to the rubber, resulting in a slow dispersion in the rubber. However, these nano-scale carbon black particles bonded to each other and having a strong specific surface area will immediately capture and adsorb the rubber macromolecules once they are forcibly dispersed by mechanical force, and finally form a uniform and dense rubber-carbon black space. Network, so small particle size carbon black can give vulcanized rubber high tensile strength and wear resistance.

After the large particle size (above 50 nm) carbon black is dispersed by ultrasonic wave, it can be clearly observed under an electron microscope with a magnification of 70,000 times. The rubber carbon black manufacturer basically appears as a single particle, and the boundary between the particles is relatively clear. It is a round or irregular ellipse. Therefore, the large-diameter carbon black is more easily dispersed into the rubber, but the carbon black-rubber network formed by the unit weight of carbon black is sparse, and the network unevenness due to the wide particle size distribution causes the strong tearing property of the vulcanized rubber. It is relatively low.