What is the structure of Pigment Carbon Black?
- The structure of pigment carbon black refers to the aggregation state and degree of basic particles of carbon black, and is also the general term for primary structure and secondary structure. The particle size of most carbon black varieties is within the nanometer size range (<100nm), and their surfaces are rich in active groups, so there is inevitably a tendency to agglomerate between particles. This is the concept of structure origin.
How are the primary and secondary structures of Pigment Carbon Black produced?
- The carbon black manufacturing process is always under high temperature conditions. Adjacent particles are generated at the same time, melt into chains, and occupy three-dimensional space. This is called a primary structure. In the post-processing stage, the primary structures form a looser structure due to physical adsorption or van der Waals forces or static electricity, which is called the secondary structure.
What types of Pigment Carbon Black structures can be divided into?
- The structure of carbon black can be divided into: high structure carbon black, medium (standard) structure carbon black, and low structure carbon black.
- Aggregates of carbon black are formed by the fusion of smaller units called primary particles, forming three-dimensional branched structures or clusters. This fusion is controlled by the reactor, resulting in varying degrees of clustering. Grades of carbon black that allow particles to agglomerate to form relatively large and complex aggregates are known as high structure carbon blacks. Carbon black grades with minimized aggregation range are called low structure carbon blacks.
What is the microstructure of Pigment carbon black?
- Carbon black particles have a microcrystalline structure. In carbon black, carbon atoms are arranged in a manner similar to graphite, forming a hexagonal plane. Usually 3 to 5 such layers form a microcrystal. Since each graphite layer of carbon black microcrystals In the crystal, the arrangement of carbon atoms is orderly, but the arrangement of carbon atoms between adjacent layers is disordered, so it is also called quasi-graphite crystal.
How to measure the structure of pigment carbon black?
- The structure of carbon black is measured through an oil absorption process called dibutyl phthalate absorption (DBPA or DBP). High structural grade carbon blacks are therefore distinguished from low structural grade carbon blacks by their higher oil absorption.
How to produce carbon black products with the expected structure? Methods to improve carbon black structure:
In order to obtain carbon black products with the expected structure, the carbon black process can be controlled. To improve the structure, the simplest way is to use raw oil with high aromatic hydroxyl content; to lower the structure, metal salts can be added to the raw oil and a smaller burner spray angle can be used.
