Graphite carbon rods have two types: natural and artificial. They are a kind of crystalline carbon with metallic luster. According to the carbon content, graphite carbon rods are divided into high carbon graphite rods, medium carbon graphite rods and low carbon graphite rods. Graphite carbon rods are widely used in electrodes of battery technology, refractories in metallurgical industry, lubricating and sealing materials in chemical industry, etc. As functional fillers of coatings, they are mainly used in fire retardant coatings, anticorrosive coatings and conductive coatings. As an anticorrosive material, if chemical pigments such as zinc yellow are added to the formula, the anticorrosive effect is better.
Expansible graphite rod used as fire retardant filler is a kind of interlayer compound of graphite rod obtained by chemical or electrochemical treatment. Expansible graphite rod expands rapidly under heating conditions and asphyxiates the flame. At the same time, it generates expansive substance, which can insulate the flame, delay or interrupt the spread of the flame, and it is non-flammable and soft. It has good softness, high surface energy and good strength of carbonized layer.
The volume and quantity of the expander should be selected properly. The experiment indicates that 150 micron particles, 30% expansion multiple and 5% dosage are suitable. Graphite carbon rods can be directly used as carbon conductive fillers, and can also be made into composite conductive fillers for conductive paints. However, due to the large amount of graphite rod scale, the performance of paint will become brittle and its application will be limited.
In summary, in order to further improve the conductivity of graphite rods, appropriate measures should be taken to effectively reduce the addition of graphite flakes. Graphite flake anticorrosive coatings have the characteristics of anti-corrosion media permeability, low residual solidification stress and good resistance to matrix deformation and cracking. The construction performance is stable and has long-term static conductivity. It can be used as electrostatic coating on the wall of crude oil storage tank.