The Properties And Application of flake graphite
What is flake graphite?
Flake graphite is a natural solid lubricant with a layered structure, rich in resources and low in price.
The flake graphite has complete crystallization, thin flakes, good toughness, excellent physical and chemical properties, and good thermal conductivity, electrical conductivity, thermal shock resistance, corrosion resistance, etc.
The application of flake graphite:
Flake graphite is widely used in advanced refractories and coatings in the metallurgical industry. Such as magnesia carbon bricks, crucibles, etc. Stabilizers for pyrotechnic materials in military industry, desulfurization accelerators for smelting industry, pencil leads for light industry, carbon brushes for electrical industry, electrodes for battery industry, catalysts for fertilizer industry, etc. After intensive processing of flake graphite, graphite emulsion can be produced, which can be used in lubricants, mold release agents, wire drawing agents, conductive coatings, etc. It can also produce expanded graphite, which is used as raw material for flexible graphite products, such as flexible graphite seals and flexible graphite composite products.
As a functional filler of coatings, flake graphite is mainly used for anti-corrosion coatings, fire-resistant coatings and conductive coatings.
As an anti-corrosion material, it is made of carbon black, talcum powder and oil, etc., which has good corrosion resistance to chemicals and solvents; if chemical pigments such as zinc yellow are added to the formulation, the anti-rust effect is better .
Expandable graphite is used as fireproof filler, which is a kind of graphite interlaminar compound obtained by chemical or electrochemical treatment with natural graphite flakes as raw material. Expandable graphite expands rapidly (up to 300 times) in volume under heating, suffocating the flame, and at the same time, it generates expansions to isolate the flame, delay or interrupt the flame spread, and it is non-combustible, flexible, and has high surface energy. , The strength of the carbonized layer is good. However, the volume and dosage of the expansion body should be selected appropriately. Tests show that 150um particles, 30% expansion ratio, and 5% dosage are the most suitable.
Flake graphite can be directly used as a carbon-based conductive filler or can be made into a composite conductive filler for conductive coatings. However, due to the large addition of graphite flakes, the performance of the coating will become brittle and its application will be limited. Therefore, measures have been taken to further improve the conductivity of graphite and effectively reduce the amount of graphite flakes added. The domestic Tianhua Chemical Machinery Research Institute has developed a high-temperature corrosion-resistant resin as the base material, and large flake solid graphite flakes with strong electrostatic conductivity as the main aggregate, with high body strength and good wear resistance.
The short-cut fiber material with good resistance to deformation and cracking is a solvent-free thick film conductive coating with a functional filler. The coating has the characteristics of anti-corrosive medium penetration, low curing residual stress, good resistance to matrix deformation and cracking, stable construction performance, and long-term static electricity conduction. It can be used for electrostatic conductive coating on the inner wall of crude oil storage tank. According to reports, the electroless plating technology is used to coat graphite powder with metals, such as copper, nickel, silver, etc., to prepare composite conductive fillers, which are used in conductive coatings in an amount of 30%, which not only has good conductivity, but also has further corrosion resistance. improve.