What is carbon black?

Carbon black is a fine powdered quasi-graphite structure formed by incomplete combustion of carbon (mainly petroleum derivatives), which appears to be pure black powder or granular. The colouring power, fineness and density of the product vary greatly according to the different raw materials and production processes. Carbon black is insoluble in water; it has acidity and alkalinity and produces carbon dioxide after combustion. The main component of carbon black is carbon, which contains trace hydrogen, oxygen, sulfur, ash, tar and water.

What is Pigment Carbon Black?

According to the statistics of 2005, the annual output of carbon black is close to 8 million tons, of which more than 90% is rubber carbon black, which is used for rubber reinforcing and automobile tires; only about 10% is used as pigment for ink, plastic and paint, which is called pigment carbon black or pigment carbon black.

Consumption of Pigment Carbon Black

Pigment carbon black, as the most important black pigments, is the third largest selling pigments product after titanium dioxide and iron oxide. The global annual consumption of pigmented carbon black (used for coloring and other special purposes, different from rubber reinforcement) is 500,000 tons. It can be seen that there is a clear difference between pigmented carbon black and rubber carbon black.

CHARACTERISTICS OF PIGMENT CARBON BLACK

1. The Best Black Pigment

2. Almost the cheapest paint

3. Compared with similar pigments, it has the best colouring and covering power.

4. The most stable pigments: have good heat resistance, chemical resistance and light resistance.

Carbon Black Technology (Production Method)

The global production processes of carbon black are furnace process, contact process (mainly groove process and grooveless gas process) and pyrolysis process. We are using the most important and commonly used production processes - furnace and gas.

The so-called furnace method is to inject liquid hydrocarbon raw materials (usually coal tar) into the burning hot air and natural gas in a closed reactor and decompose them by thermal oxidation at high temperature. The properties of carbon black can be controlled by quenching the flame. Then, the pigmented carbon black is separated from the smoke by a filter system. Furnace process is characterized by a wide range of raw materials, and the production of carbon black has a variety of properties.

The gas process, i.e. the non-tank gas process, is a production process improved from the tank process. Tank method is a process in which solid hydrocarbons (crude anthracene) or liquid hydrocarbons (anthracene oil) are gasified in a gasifier and mixed with combustible gases (natural gas, coke oven gas or water gas) as raw materials. The annular pipe network is fed into the fire chamber under the channel steel to burn at high temperature and collect carbon black through the cooling surface of the channel steel. The improved technology of slotless gas method is that there is no slotted steel cooling surface in the fire room. The yield of carbon black produced by this process is lower than that by furnace method, but the particle size of primary particles is small, which has better performance in blackness and colouring power.

Powdery and granular carbon black

Pigment carbon black has two apparent forms: powdery and granular. Powder is easy to disperse but highly polluted, fluffy and fluidity is weak. Granular carbon black has smaller dust emission, smaller volume and easier transportation, but its dispersion is weaker than that of powdery carbon black.

In order to help standardize the promotion of our products worldwide, we registered our own trademarks: PowCarbon? For powdery carbon black trademark; BeBlack? For granular carbon black trademark: to facilitate the differentiation of our different forms of products.

Common Knowledge of Pigment Carbon Black

Particle size:

The primary particles of pigment carbon black are composed of many overlapping layers. To a large extent, the production process determines the size of the primary particles. Among the carbon black produced by furnace method, the change range of primary particle size is the largest: from 10 nanometer to 80 nanometer. The average particle size and particle size distribution of primary particles fundamentally determine the properties of carbon black, especially its blackness and colouring power.

Structure (oil absorption value)

Pigment carbon black primary particles do not exist in a separate state. They form melts and aggregates by physical action. The agglomeration degree of furnace blacks can be adjusted by technological changes, while the agglomeration degree of gas blacks is difficult to control. The degree of aggregation of carbon black primitive particles is often referred to as "structure". High aggregation carbon black is called high structure carbon black, while low aggregation carbon black is called low structure carbon black. The aggregates formed by pigment carbon black show irregular fragmentary structure.

The structure of carbon black can be measured by DBP (dibutyl phthalate) absorption value. According to experience, the DBP absorption value of 100 g carbon black in low structure pigments should not be higher than 70 ml, while that of 100 g carbon black in high structure pigments should not be lower than 110 ml. Medium-structured carbon black is between the two. The structure has a substantial effect on the application of carbon black. (Reference to ASTM D-2414 standard or GB/T 10722-2003)

Coloring power

The colouring power of carbon black is usually expressed in percentage form, which can be measured by the data obtained from the measurement of carbon black dilution paste with a blackness reflector. According to the industrial standard operation, the color paste is a mixture of carbon black and titanium dioxide (or other white pigments such as zinc oxide) and a certain solvent.

(Colouring force measurement refers to ASTM D-3849 or GB/T7046-2003 standard)

specific surface area

The specific surface area of carbon black refers to the total surface area of carbon black particles per unit mass or volume, which is m2/g. Specific surface area is one of the basic properties of carbon black as particle size. For smooth carbon black, the specific surface area is inversely proportional to the particle size, that is, the smaller the particle size, the larger the specific surface area, and vice versa. Therefore, if the carbon black particles are assumed to be spherical, the specific surface area can be calculated from the particle size data.