What are the properties of carbon black?

The properties of carbon black are extremely complex. Generally, the particle size and specific surface area, structure, and surface properties of carbon black are referred to as the three major properties of carbon black.

The particle size is usually the average diameter of carbon black particles, referred to as the particle size, measured using m μ The measurement method includes an electron microscope, a microscope scale, or a particle size analyzer. The particle size measured using an electron microscope can be used to obtain the particle size and distribution, which can be represented by a particle size distribution curve. The abscissa represents the range of particle sizes, and the ordinate represents the percentage of particles.

Specific surface area refers to the total specific surface area of carbon black per unit weight or volume. In general, the smaller the particle size of carbon black, the larger the specific surface area, and the higher the dispersion. Carbon black also has external specific surface area, internal specific surface area, and total specific surface area. Measurement methods include air permeation method, solution adsorption method, gas or vapor adsorption method, and electron microscope method. Currently, the most commonly used method is low-temperature nitrogen adsorption method.

The structure of carbon black represents the chain like and grape like polymerization degree between carbon black particles. Generally, the oil absorption value is used to represent the structure. The higher the oil absorption value, the higher the structure of carbon black, which is easier to establish spatial network channels and difficult to destroy.

Surface properties of carbon black: Carbon black is mainly composed of carbon, with a carbon content of 90% to 99%, and also contains a small amount of hydrogen, oxygen, nitrogen, and sulfur. It also includes surface functional groups such as carboxyl, lactone, phenolic, carbonyl, etc. The chemical properties are usually represented by indicators such as volatile matter and pH value, while the physical properties are represented by porosity and roughness.

What are the properties that affect conductive carbon black:

The oil absorption value of conductive carbon black indicates the structural performance of carbon black. Generally speaking, when the oil absorption value is high, the conductive carbon black has a chain like structure and good electrical conductivity.

The smaller the particle size of conductive carbon black, the more particles per unit volume, which is more conducive to enhancing electrical conductivity.

3. The volatile content of conductive carbon black is generated by some organic groups and an oil film that has not yet been fully cracked to form an insulating layer, which increases the potential barrier between carbon black particles and seriously affects the electrical conductivity. Therefore, it is necessary to control the volatile content to a low level.

The roughness of carbon black makes it prone to generate conductive channels, which requires a large difference between the nitrogen absorption surface area and the CTAB surface area of carbon black.

5. When the ash and moisture content of conductive carbon black is high, the content of carbon black will decrease, affecting the conductivity of carbon black. Therefore, the ash and moisture content of carbon black should be reasonably controlled.

What are the properties that affect pigment carbon black?

The average particle size and particle size distribution of primary particles fundamentally determine the performance of pigment carbon black, especially its blackness and coloring power. According to the different particle sizes, it can be divided into high pigment carbon black, low pigment carbon black, and medium pigment carbon black.

The larger the surface area of carbon black, the greater its blackness and UV resistance, mainly because it can increase the area for absorbing visible and UV light.

3. Coloring power is one of the important indicators of pigment carbon black, representing the dyeing ability of carbon black. In general, the higher the coloring power, the stronger the hiding power.

4. The hue is an important indicator of high-end pigment carbon black, which can adjust the color of the product.