Analysis of the international development trend of graphene anti-corrosion coatings

First,
graphene heavy anti-corrosion coatings overview
coating industry is located at the end of the chemical industry chain in the field of fine chemicals, is the main application of basic chemicals in the upper and middle reaches. According to Global Market Insights, a market research firm, the global market for corrosion-resistant coatings will reach $20.21 billion by 2024, with a compound annual growth rate of about 5%. Among them, heavy anti-corrosion coatings are the most powerful, most representative and influential anti-corrosion coatings, and the most development potential of a class of protective coatings, with its excellent protection performance, mainly used in ships, containers, petrochemicals, construction steel structure, railways, bridges, electric power and water conservancy projects and many other important areas related to national development strategy and economic lifeline, is to measure a country's paint industry development level of one of the important signs
China

Because graphene heavy anti-corrosion coatings have the advantages of light weight, long life, conductivity and better thermal conductivity, they can overcome the harsh conditions of chemical heavy polluted gases and complex marine environment, and become the focus of research and development in all countries of the world. For example,
EU
launched its flagship graphene program in 2013 and listed "functional coatings and interfaces for high-performance, lightweight technology applications" as 13 key research and development priorities in the graphene flagship program roadmap released in 2014 in 2011

<1> <0> listed graphene as one of the four key development directions for the future in its Innovation and Development Strategy for Growth, at a cost of ￡38 million to build a national level at the University of Manchester Graphene Research Institute, and graphene coatings as a research focus;
America
National Nanotechnology Program to coordinate federal research and development resources, from basic research to commercial applications, systematically promote graphene coatings research and development and industrialization;
China
Man making 2025" graphene materials technology roadmap proposed that marine engineering and other graphene-based corrosion-resistant coatings than traditional anti-corrosion coating life more than doubled and achieve large-scale applications, the industrial scale of more than 10 billion yuan.
application of graphene in conductive coatings
automotive electrostite spray light primer
automotive is an important industrial product. As an integral part of automobile composition system, automotive plastic parts have a good market space. At present, car plastic parts coating is generally used in conventional air spraying operation. This paint industry is based on the gun as a tool, the use of compressed air as a carrier for production. In the production process, a large number of coatings in the form of atomization into the air, not only expensive, but also will cause more serious air pollution. For this reason, automotive and coating enterprises have been more economical, environmentally friendly new coatings as the main development goals of automotive coatings. Among them, electrostectrectectectectrative spraying is one of the important directions.
electrostectrical spraying to electric field as the coating loader, not only high efficiency of paint utilization, relatively low cost, conducive to environmental protection, but also has the advantages of fast production speed, high decorative performance. A large part of the automobile components, such as car body, bumper, interior and exterior trim, etc., are plastic products, can not form an electric field. In order to realize the electrostectrical spraying process, it is necessary to first apply a conductive primer on the surface of the processing part, and then carry out electrostectrical spraying. At present, automotive spray conductive primers mainly by adding conductive carbon black to make the coating conductive. As a result, the conductive primer color is darker, in order to be beautiful, often to spray a layer of primer to cover, and then carry out formal electrostectrical spraying. This method is complex in process and increases in cost, so it is more difficult to popularize.
use graphene as a conductive agent, you can avoid the problem of darkening the primer color due to the conductive agent, which is very beneficial to the improvement of static spraying in automobiles. Data show that with 2% to 4% graphene added, the primer coating value is 40 to 50, which can fully meet the color requirements of automotive electrostitectrical spraying.
conductive electrostectrecture coatings
graphene in conductive coatings is another important application area is conductive electrostectrectrecture coatings. The surface resistance of the coating is usually located between 106 and 109, which can effectively prevent the phenomenon of electrostation conduction, so it is generally used in high-demanding situations such as fire prevention and explosion prevention. For example, oil, chemical, railway, transportation and other industries oil storage tanks, pipelines, tankers and other oil storage, oil transmission equipment inside and outside the wall, coal mines, aviation, textiles, food and other industries equipment anti-corrosion coatings are generally used as anti-corrosion coatings, so as to maximize the prevention of equipment corrosion, but also to avoid the collection of charge to cause static electricity caused by fire accidents. Graphene is both conductive and corrosion-resistant, so it works well in electrostitive coatings.
graphene in the field of anti-corrosion coatings
enoxy zinc-rich paint
anti-corrosion coatings have been one of the important branches of coatings, in industrial production is widely used. In the national economic production, the use of a large number of metal products make equipment anti-corrosion requirements are very high, anti-corrosion coating market demand shows a continuous upward trend. Statistics show that the global economic losses caused by corrosion each year amount to trillions of dollars, far more than the economic losses caused by natural disasters. Graphene is added to the existing epoxy anti-corrosion coating, and in addition to the original performance, the resistance, adhesion, water resistance, hardness and other indicators are improved. It is widely used in marine engineering, transportation, large-scale industrial equipment and municipal engineering facilities.
water-based anti-corrosion coatings
environmental protection coatings are the main direction of current coating development. Water-based coatings have become an important development goal of environmentally friendly coatings because of their low VOC. Water-based coatings use water as a dispersant, the surface tensor is high, the film-forming film has not been ideal. Adding graphene to water-based anticorrosive coatings can improve this.
application of graphene in the field of flame retardant coatings
graphene monolithic secondary structure, dispersed to the lacquer film layer by layer, forming a dense isolation layer, can play a fire retardant role. If the resin is added to the coating, graphene can also be cross-linked with the resin molecules, further strengthening the isolation effect, flame retardant effect is strengthened. In addition, the graphene coating after combustion products in addition to carbon dioxide and water, but also in the original will leave a continuous distribution of carbon layer, thereby again improving flame retardant effect. For this reason, graphene also has a good application in flame retardant coatings.
application of graphene in high thermally conductive coatings
graphene has a high thermal conductivity. Adding graphene to the coating can significantly improve the thermal conductivity of the coating. Therefore, graphene modified has become an important development direction of thermal coatings. In addition, graphene than the surface area is very large, the paint film contains a certain amount of graphene, can make the paint film cooling area greatly increased, help the paint film surface and internal heat distribution, so that the internal and external temperature tends to be consistent. Graphene coatings are commonly used as thermal coatings for components in many harsh environments due to their mechanical properties, corrosion resistance and aging resistance.
application of graphene in high-strength coatings
because of its high surface area, it has a strong adsorption force. After adding graphene to the coating, it forms a mesh structure in the process of curing the paint film, which greatly enhances the bondability of the paint film and substrate, and the paint film is more stable and stronger. The test results show that after adding graphene, the impact resistance, friction resistance, thermal conductivity, weather resistance and corrosion resistance of the coating have been greatly improved.
,
Graphene heavy anti-corrosion coating research progress
Under the strong promotion of various countries, graphene anti-corrosion coating basic research and engineering applications have made a lot of progress. The main research work focuses on the use of graphene to change a variety of traditional coatings, with targeted to improve the performance of traditional coatings. Such as improving the improved density, hardness, flexibility, high temperature resistance, conductivity and other aspects of epoxy anti-corrosion coatings by reducing the zinc content in traditional epoxy-rich zinc primers to improve the bonding force and density of resins, graphene efficient and uniform dispersion, optimization of the selection of components, etc.; Hardness, impact strength, mechanical properties and thermal shrinkage, etc., by using the conjugate agent and graphene conjugate to prepare a composite polyurethane coating of graphene nanochips, using electrochemical deposition technology to grow graphene on the copper substrate and spread it evenly, using titanium ester conjugate modified graphite oxide and other methods, improve polyurethane corrosion protection, decomposition temperature, mechanical properties, thermal shrinkage performance, anti-sink performance. Graphene inorganic anti-corrosion coating research is relatively small, the main research work includes the use of bump rod soil as a dispersant of graphene and zinc powder, reduce the occurrence of reunion phenomenon, graphene instead of metal chromium added Dacro coating, improve corrosion resistance, can eliminate heavy metal chromium pollution to the environment, graphene added to inorganic silicate coating, greatly improve coating adhesion and so on.
technical obstacles to the development of graphene modified coatings. Graphene is indeed an excellent protective material, but the problem is that there are too many defects in the graphene sheet layer made using the current synthesis method, such as chemical key loss, lattic distortion, local thickness fluctuations and doping impurities. These defects can lead to oxygen build-up, which can reduce the protective properties of the graphene sheet layer, especially during long-term testing. Although graphene is well resistant to corrosion, it is relatively cathode with most metals and can lead to further corrosion of exposed graphene-metal interfaces, which can accelerate corrosion and severely weaken protected metals.
third,
graphene heavy anti-corrosion technology patent analysis
by searching the Thomson Innovation patent database, a total of 572 graphene anti-corrosion coating technology-related patents (family). Since 2010, the first graphene anti-corrosion coating patent has appeared, and since then the number of patent applications has increased year by year, between 2010 and 2016, the average annual growth rate of more than 50%, graphene anti-corrosion coating technology from the emergence of this technology, the momentum of development is very rapid. With the exception of China, patent applications in graphene anticorrosive coatings technology were concentrated in 2013-2015. Over the entire period of time, Chinese patents have occupied an absolute majority, which shows that China has basically dominated the technological development of this field (Figure 1).
Figure 1 Graphene anti-corrosion coating technology in major countries
annual distribution of patent applications
This time the graphene anti-corrosion coating patents were retrieved involving a total of 494 IPC classification numbers, which cover 521 patents, accounting for more than 91% of all analytical patents. Graphene anti-corrosion coating technology patent applications are mainly concentrated in the C09D category, that is, coating compositions, filled slurry, chemical coatings and so on. The number of patent applications for coating compositions based on epoxy resins and their derivatives reached 201, 104 patent applications for graphene anticorrosive coatings containing metal powders, 74 patents related to conductive coatings, 71 for coating compositions based on 1 or more unsaturated lipid family-based compounds, and 71 for polyurethane or polyurethane-based There are 52 patents for coating compositions and coating compositions based on such polymer derivatives, 43 patents for coating compositions based on coating compositions based on such polymer derivatives based on silicon-containing, with or without sulfur, nitrogen, oxygen or carbon bond reactions formed in the main chain (Table 1).
From the distribution of the main patent rights of graphene anti-corrosion coating technology, in addition to the Chinese Academy of Sciences Ningbo Materials Institute, Changzhou University, Nanjing University of Aeronautics and Astronautics, Shanghai University and a few other scientific research institutions and universities, most graphene anti-corrosion coating technology patent applications are mainly led by enterprises. However, Ningbo Materials Institute and Changzhou University in the field of graphene anti-corrosion coating technology has applied for a large number of patents, through the relevant public reports, including these two research institutions, including domestic research institutions, through cooperation in industry and research to promote the rapid development and industrialization of China's graphene anti-corrosion coating technology (Table 2).
Table 2 The patente of the main graphene anti-corrosion coating technology and his patent
application time distribution
Fourth,
graphene heavy anti-corrosion technical paper analysis
This report searched the Web of Science database, a total of 519 papers related to graphene anti-corrosion coating technology. Papers from China, the United States and Germany in the field of graphene anticorrosive coatings have appeared late in other countries since 2011, but mostly from 2012 to 2013, there is no significant difference (Figure 2). In terms of trends, the number of papers in China has grown much faster than in other countries, and the number of papers in China has increased sharply since 2012. Relatively speaking, although the number of papers in the United States, South Korea and other countries has also increased to a certain extent, but the increase is not large, especially in the last two years, the number of papers published has not increased significantly, or even fell back. However, India and Iran, despite their relatively late starts, have outsed other countries outside China in terms of the number of papers that have grown in the past two years.
2 Number of graphene anticorrosive coating research papers country
time-based trends
H index can reflect the number and quality of academic output of institutions. In Table 5, the institutions with higher H indices are the Chinese Academy of Sciences (10), Tsinghua University (7) and India's CSIR (7). This suggests that at the composite level, the three research institutions are higher than the other institutions in the table.
In the Chinese Academy of Sciences, Ningbo Materials published the largest number of relevant papers (13), followed by Qingdao Ocean Institute (9), Lanzhou Chemical Institute (7), Shanghai Microsysyscopy Institute (4) and Metal Institute (4). In terms of frequency, Shenyang Metals' papers were cited the highest number of times, reaching 32 times, and Shanghai Silicate Institute's papers were cited a higher number of times, with an average number of 20.3 articles. In terms of the H index, Ningbo Materials Has the highest H index, at 10, indicating that the number of highly cited papers is ahead of other institutes in the institute (Table 3).Table
3 Number of papers published by various institutions in the field of graphene anticorrosive coatings,
citation frequency and H index
From the paper's articles are cited frequency, Taiwan's Central Plains University has been cited frequency 26.6 times, followed by Indian science and industry