Carbon black pigment dispersion aim is to make it in a homogeneous distribution in the carrier, the distribution of such different levels, will directly affect the product hue, blackness and hiding. The main subject of the carbon black dispersion three factors: the size of the primary particles of carbon black pigment, the level of the structure and other properties; type of carrier or dispersion medium, after adding the dispersant, will be coated on the surface of carbon black particles, which to some extent reduce the cohesion between the particles of carbon black, the carbon black dispersion contributes; type dispersing device is used.
Dispersion of carbon black is critical in practical applications, carbon black is used in the coloring, if carbon black is poorly dispersed will result in the following consequences:
1, the color intensity is unstable, pigment carbon black blackness is not a good show, and the apparent bad color;
2, the uneven distribution of streaks;
3, in inks, coatings and other products in the uneven surface can cause printing problems;
4, filtration screen extruder is blocked; in extrusion blown film when the new moon, unbroken black agglomerates cause the bubble to tear;
5, causing monofilament and flat yarn breakage, the mechanical strength of the product is reduced.
Carbon black dispersion is ground, carbon black pigment particles to achieve a certain degree of fineness is the minimum requirement. Under normal circumstances it should fineness ≤15 um, in the upscale paint, there will be higher demand even lower than 5um, the lower the moisture contained in the carbon black pigment, the dispersion will also relatively easier some. This is because in a decentralized system, the level of carbon black pigment particles are electrostatically each other, their electric double layer thickness formed around, and if the thickness of the electric double layer is lowered, it will directly affect the reduced particle dispersion stability. When carbon black (or other color) higher water surface of the particles, it will lead to lower electric double layer thickness, which affects the dispersion stability.