Particle size
The particle size of carbon black refers to the primary particle size of carbon black. It is measured by an electron microscope and is the average value of a certain number of particle sizes.


Tinting power
Also called coloring intensity. It is the coloring ability of carbon black when white or color pigments are mixed with carbon black. That is, the extent to which carbon black improves the light absorption effect of the mixture. It is usually expressed as a percentage and can be measured by measuring the data obtained by diluting the carbon black with a black reflectometer.


Specific surface area
The specific surface area of carbon black refers to the total surface area of carbon black particles per unit mass or unit volume, and the unit is m2 / g. Specific surface area is the same as particle size. Generally speaking, the specific surface area of relatively smooth carbon black (such as carbon black for rubber) is exactly inversely proportional to the particle size, that is, the smaller the particle size, the larger the specific surface area, and vice versa. Therefore, if carbon black particles are assumed to be spherical, the specific surface area can be calculated from the particle size data.


The specific surface area of carbon black is divided into external specific surface area (or smooth specific surface area), internal specific surface area (or specific surface area within pores) and total specific surface area. The total specific surface area is equal to the sum of the external specific surface area and the internal specific surface area. There are many methods for measuring the specific surface area. Commonly used methods include nitrogen adsorption method (BET method), iodine absorption method, CTAB method (macromolecule adsorption method), t value method, and electron microscope method.


4. DBP absorption value
The structure of carbon black can be measured with a DBP (dibutyl phthalate) absorption value. According to experience, the DBP absorption value per 100g of carbon black in low-structure pigment carbon black should not be higher than 70ml; while the DBP absorption value per 100g of carbon black in high-structure pigment carbon black should not be lower than 110ml. Medium structure carbon black is in between. The structure has a substantial effect on the applicability of pigment carbon black.


5. PH value
The pH is related to the number of surface functional groups. Furnace carbon black has few functional groups on the surface and a small amount of soluble salts, so carbon black itself is mostly neutral or alkaline. In order to improve the viscosity, stability and fluidity of carbon black, some pigment carbon blacks can be surface acidified by changing the number of surface functional groups.


6. Density
The weight of carbon black per unit volume is (g / l), which indicates the size of the space occupied by various types of carbon black. The larger the particle size, the greater the density of performance, and the smaller the particle size, the smaller the particle size. Dispersion has an impact.