What is carbon black?
Carbon black material is also known as acetylene black, channel black, furnace black, lamp black, and thermal black. It is a black solid with molar mass 12.01 g/mol. The density of carbon black at 20°C is 1.8–2.1 g/cc.
When carbon-rich organic liquids like kerosene, petrol, turpentine oil, benzene etc. are burned in controlled air, they burn with a kind of black smoke.
When this smoke condenses, it causes soot. This is called lampblack or soot. Carbon black is the lampblack obtained from the smoke emitted when natural gas or mainly methane is ignited in a controlled atmosphere.
Read also: What is catenation property of carbon?
Soot or lampblack is the purest allotrope among the amorphous allotropes of carbon. Carbon black is amorphous, black in color and incapable of conducting heat and electricity.
Carbon black is produced by the incomplete combustion of heavy petroleum products such as fluid catalytic cracking tar, coal tar, ethylene cracking tar, or vegetables matter. It is practically insoluble in water.
Carbon black is a form of paracrystalline carbon that has a ratio of volume to high surface area, although less than that of activated carbon.
It is dissimilar to soot in its much higher surface-area to volume ratio and significantly lower polycyclic aromatic hydrocarbon content.
However, carbon black is widely used as a model compound for diesel ink for diesel oxidation testing.
Carbon black is mainly used as powerful filler in tires and other rubber products. In plastics, paints and inks, carbon black is used as a pigment.
When produced from vegetable substances it is used as food color in some places like EU. The current International Agency for Research on Cancer’s assessment is that “carbon black is probably carcinogenic to humans.
Short-term exposure to high concentrations of carbon black dust can cause upper respiratory tract discomfort through mechanical irritation.
What Is Carbon Black Used For?
Carbon black is widely used in the manufacture of printing ink, shoe ink and various types of black paint. The different uses of carbon black are discussed below.
Common uses of Carbon black
Carbon black is used as a pigment and reinforcing phase in automobile tires. Carbon black helps to remove heat from the tread and belt area of the tire. It also reduces heat loss and prolongs the life of the tire.
Carbon black mainly used as a pigment in ink, coating and plastic. Carbon black particles are also used in some radar absorbers, photocopiers and laser printer toners and other inks and paints.
The high color strength and durability of carbon black has also provided use in resin and film colors. Carbon black has been used in various applications for electronics.
Carbon black is used as a good conductor of electricity, carbon black plastic, elastomer, film, adhesive and dye mixed filler. It is used as an antistatic additive agent in automobile fuel caps and pipes.
Carbon black from vegetable sources is used as a food color. The color pigment carbon black has been widely used in food and beverage packaging for many years.
Carbon black reinforcement
The maximum amount of carbon black is used as reinforcing filler in rubber products, especially tires. About 50% carbon black is used as weight in the vulcanization process to improve the tensile strength and wear resistance of styrene-butadiene.
Virtually all rubber products use carbon black where tensile and friction wear properties are important.
Use as pigment
Carbon black is the name given to a common black pigment, which is traditionally derived from organic matter such as wood or bone. It is known by various names. Ivory black is traditionally produced by ivory or bone.
The vine black is traditionally produced by the delicious grape vines and stalks. The black of the lamp was traditionally made by collecting ink from oil lamps.
All of these types of carbon black have been widely used as paint pigments since prehistoric times. Rembrandt, Vermeer, Van Dyke, and more recently, Cezanne, Picasso, and Manet have employed carbon black pigments in their paintings.