Static conductive coatings are mainly used on the inner wall of petrochemical storage tanks to prevent the accumulation . During the process of filling and discharging, the oil product will move relative to the tank body, which will increase the static voltage on the inner wall . During the process of flowing, filtering, mixing, spraying, spraying, flushing, filling and shaking, etc., the static charge will also accumulate static charge because the speed of the static charge is higher than the discharge speed.
When the discharge energy of the accumulated electrostatic charge is greater than the minimum ignition energy of the flammable mixture, and the mixture of oil vapor and air is within the explosion limit range in the discharge gap, combustion and explosion will occur, and the consequences will be very serious.
From the structural analysis of the coating, the electrostatic charge of the coating is mainly caused by the high surface resistance of the film-forming material of the coating , which makes it difficult to leak the generated static charge and accumulate more and more static charges .
In order to ensure the safety of oil storage tanks, suppress the generation of static charges and promote the discharge of charges, and eliminate the accumulation of static charges, the inner wall of the oil tank can use static conductive coatings, and the volume resistivity of the coatings should be as low as 10 8 Ω cm , the surface resistance should be lower than 10 9 Ω .
The main varieties of electrostatic conductive coatings are epoxy and polyurethane, solvent-based and solvent-free. Conductive pigments mostly use non-graphite conductive mica powder.
