Anti-corrosion coatings, generally divided into conventional anti-corrosion coatings and heavy anti-corrosion coatings, is an essential coating in paint coatings. Conventional anti-corrosion coatings are used to protect non-ferrous metals from corrosion under general conditions; heavy-duty anti-corrosion coatings are used in relatively harsh corrosive environments and have a longer protection period than conventional anti-corrosion coatings. The chemical principle of anti-corrosion is to neutralise harmful acid and alkali substances into neutral harmless substances to protect the materials within the anti-corrosion coating from corrosive substances.

The physical principle of corrosion protection is to separate the protected material from corrosive substances in the outside world by means of an anti-corrosion coating.   The electrochemical effect of anti-corrosion refers to the addition of some special substances in the anti-corrosion coating, so that in the water and oxygen through the anti-corrosion coating will react and the formation of anti-corrosion ions, so that the surface of steel and other metals passivated, thus preventing the dissolution of metal ions, to reach the purpose of anti-corrosion, the most common of such special substances is chromate. Amongst other things, heavy anti-corrosion is extremely demanding on the coating performance process and is the most extreme expression of anti-corrosion coating technology.
Heavy duty anti-corrosion coatings: compared to conventional anti-corrosion coatings, can be applied in relatively harsh corrosive environments and have a class of anti-corrosion coatings that can achieve longer protection periods than conventional anti-corrosion coatings. The main difference between heavy anti-corrosion coatings and conventional anti-corrosion coatings is their high technical content and technical difficulty, involving many aspects of technological progress and product development, which need to be integrated into the heavy anti-corrosion coatings and coating. Therefore, the technical level of heavy anti-corrosion coatings has become a symbol of the advanced or not in the anti-corrosion industry.

The main types of heavy anti-corrosion coatings:

1. Epoxy type heavy anti-corrosion coatings

Epoxy resin is a thermosetting resin containing two or more epoxy groups in the macromolecular chain, with good film-forming properties and excellent corrosion resistance characteristics.

2. Polyurethane heavy-duty anti-corrosion coatings

Polyurethane resin has many excellent properties due to the active cyanate groups in its molecular structure: good flexibility, strong adhesion, excellent wear resistance and mechanical properties, and good anti-corrosion properties of the paint film.

3. Zinc-rich heavy-duty anti-corrosion coatings

As one of the common primers in modern heavy anti-corrosion coating systems, zinc-rich coatings use sacrificial zinc powder to make the coating conductive in a corrosive environment to achieve the effect of protecting the metal substrate, so its dry film zinc powder content can reach about 80-95%.

4. Fluorocarbon coatings

Fluorocarbon coating is mainly a kind of room temperature curing coating with organic fluorine polymer as the film-forming resin, and the common room temperature curing fluorocarbon coating on the market mainly uses resin fluorine olefin - vinyl ether copolymer (FEVE) and end-hydroxy perfluoropolyether (PFPE).

5. Polyurea heavy-duty anti-corrosion coatings

An innovative spray polyurea elastomer technology developed by American companies in the last century, the technology is based on the reaction of end-amino polyether, diamine chain extender active hydrogen component and isocyanate component, which has the advantages of fast curing, low environmental impact during construction, extremely high wear resistance, anti-aging and corrosion resistance due to its excellent anti-corrosion comprehensive performance.

Of the above heavy-duty anti-corrosion coatings, zinc-rich anti-corrosion coatings are the most common and have the widest range of uses. The zinc powder anti-corrosion coatings also have some unavoidable disadvantages:
Zinc powder anti-corrosion coating, the coating of the substrate surface requirements are high; zinc powder anti-corrosion coating in the high content of zinc powder, the specific gravity of easy to deposit, construction is difficult, the construction of a large thickness will occur paint film cracking; zinc powder anti-corrosion coating paint film surface is porous structure, will be residual air.

Therefore, in recent years, Microcrystalline Technology has developed graphene anti-corrosion coating, which can overcome the above shortcomings of zinc powder anti-corrosion coating: the stacking effect of the graphene graphene layer structure can form a "labyrinth" shielding structure in the coating, which can effectively inhibit the infiltration, penetration and diffusion of corrosive media and improve the physical barrier of the coating. If graphene from Microcrystalline Technology is added to the zinc powder primer, its conjugated structure gives it good electrical conductivity and its lamellar structure ensures good electrochemical contact between the coatings, forming a conductive network and providing better electrochemical protection. Due to its hydrophobic nature, graphene forms a water barrier on the surface of the coating, thus enhancing the corrosion protection. Graphene creates a net-like dense structure on the surface of the paint film, which greatly enhances the adhesion and stability of the coating to the substrate.

In addition, graphene coatings have an important problem to be solved: but graphene flakes are not hydrophilic nor lipophilic, and due to van der Waals forces are also prone to agglomeration, it is difficult to long time stable dispersion in solution, need a more fully integrated dispersion of graphene, preferably directly add the active ingredients can be prepared into graphene anti-corrosion coatings, which will greatly reduce the preparation of graphene anti-corrosion coatings and This will greatly reduce the difficulty and cost of preparing graphene anti-corrosion coatings. The following is a water-based graphene dispersion that can be directly formulated into graphene anti-corrosion coatings: this graphene dispersion is compatible with most of the water-based systems currently on the market, and it can be used as an additive in a variety of fields such as anti-bacterial fibre products, water-based conductive coatings, water-based thermal inks, water-based heat dissipation coatings and lithium battery anode materials. It can give the system good antibacterial, conductive and heat dissipation properties.