The main types of anti-fouling coating development: ① does not contain organic tin self-polishing anti-fouling coatings; ② abrasive anti-fouling coatings without tin; ③ non-toxic anti-fouling coatings ( low-surface-energy coatings, bio-fouling coatings ); ④ conductive anti-fouling coatings. Which does not contain organic tin low-toxic or non-toxic antifouling coatings for the main research and development goals, to Wuxi self-polishing or abrasive antifouling coatings product development is the fastest. Wuxi self-polishing anti-fouling coatings with long-lasting anti-fouling and energy-saving features, while meeting the requirements of environmental protection, both economically and militarily are of great practical significance.
Low surface energy antifouling coatings commonly known as "non-stick" coating. It is the use of paint surface with low surface energy of the physical properties of the sea creatures are difficult to attach or even if the adhesion of its adhesion is also very small, in the ship at low speeds, by the action of sea water shear force is very easy to be removed. Existing low surface energy antifouling coatings are mainly made of organosilicon and organofluorine resins as base resins, utilizing the low surface energy properties of organosilicon and organofluorine. These antifouling coatings have been applied in practice, and their antifouling period can be up to 5 a.
Biological antifouling coatings with natural antifouling agent is the use of biotechnology from a variety of marine plants and animals and land plants extracted from the natural prevention of sea life fouling substances, mainly macroalgae antifouling agent, bitter dynamic tree antifouling agent, acylated danio leaf rhododendron mytilus antifouling agent, horseradish antifouling agent, spongy fatty acid antifouling agent, antifouling agent containing decomposition of proteolytic enzymes, etc.. Bionic antifouling coatings utilize the principle of bionics. There are 2 main directions: ① extracting natural active substances in the ocean as antifouling agents; ② simulating the epidermal structure of large marine animals to realize antifouling. Biotechnology is a high-yield industry, the use of biotechnology production and production of the above types of antifouling agent, harmless to human beings, the environment and marine life, the development of this field will produce huge social and economic benefits.
Conductive antifouling coating is to coat several layers of conductive paint on the surface of the hull shell, when a small direct current passes through the surface coated with conductive paint, it will cause seawater electrolysis to produce sodium hypochlorite, to achieve the purpose of preventing seabreaths from adhering to the surface of the hull. There are three ways to realize low VOC anti-fouling coatings: ① water-based anti-fouling coatings; ② powder anti-fouling coatings; ③ high solid content anti-fouling coatings. At present, the research and development of low VOC anti-fouling coatings at home and abroad have been reported only in the water-based anti-fouling coatings.
Marine anti-fouling coatings are one of the most important varieties of marine coatings, directly affecting the interests of shipowners and the marine environment, so researchers and coating suppliers strive to develop more environmentally friendly, better performance, more competitive marine anti-fouling coatings.
Anti-fouling technologies also include electrochemical anti-fouling methods, new methods of controlling corrosive microorganisms - electrochemical sterilization and applied potential anti-fouling methods.
2. 2 Antirust coatings for ship hulls
The current varieties of antirust coatings for ship bottoms can be roughly divided into three categories: ① traditional asphalt and oil-based system; ② high-performance antirust coatings for ship bottoms based on epoxy, vinyl, epoxy asphalt, vinyl asphalt, and chlorinated rubber resins as the main body of the antirust coatings for ship bottoms; ③ new high-performance antirust coatings for ship bottoms, including modified epoxy, glass scale coatings, fluorine resin coatings, and so on.
2. 3 special functional coatings for ships
Special coating materials for ships are an indispensable part of ship equipment. It involves the following areas: high temperature resistance, heat insulation, fire prevention, acoustic damping, wave absorption, optical camouflage, etc., mainly naval radar absorbing stealth coatings, absorbing sonar wave coatings, infrared stealth coatings, anti-thermal radiation coatings, anti-skid coatings on the flight deck, high-temperature coatings, etc., although the amount is not large, but the ship is indispensable and replacement of the supporting materials, and with the accelerated modernization of armaments, the special coating materials play a role in the various parts of the ship. The role played by the materials in the various parts of the ship more and more.
3 wave-absorbing coatings
Wave-absorbing coatings are capable of absorbing electromagnetic energy projected onto its surface, and through the loss of materials into a class of thermal energy materials. Wave-absorbing coatings are mainly composed of absorbers and binders. The absorber containing specific electromagnetic parameters is the key of wave-absorbing coatings and determines the wave-absorbing performance of wave-absorbing coatings; the binder is the film-forming material of the coating, which is the main material to make the coating firmly adhere to the surface of the coated object and form a continuous film. Wave-absorbing coatings can be generally divided into the following categories according to different absorbers: ferrite wave-absorbing coatings, carbonyl iron wave-absorbing coatings, metal ultrafine powder or metal oxide magnetic ultrafine powder wave-absorbing coatings, ceramic wave-absorbing coatings, nano-wave-absorbing coatings, radioisotope wave-absorbing coatings, conductive polymer wave-absorbing coatings, retinol-based Schiff alkali salts wave-absorbing coatings, significance of the wave-absorbing coatings, doped high-loss material wave-absorbing coatings, rare earth elements Wave-absorbing coatings.
Research on high-performance, broadband absorbing coatings to broaden the effective frequency band, to achieve multi-spectrum stealth effect for the main direction of the future development of absorbing coatings. At the same time, the study of a variety of new absorbers, explore new wave-absorbing mechanisms to meet the wave-absorbing coatings pursued by the "thin, light, wide, strong" goal.
Wave-absorbing coatings are one of the main military invisible materials, in civil applications on a wide range of products, such as human safety protection, microwave darkroom to eliminate electromagnetic interference with equipment and communications and navigation systems, security information confidentiality, improve the performance of the entire machine to improve the signal-to-noise ratio, electromagnetic compatibility, as well as the waveguide or coaxial absorption components, radio and television transmitters electromagnetic radiation protection, industrial science and medical equipment, electromagnetic radiation protection, daily necessities. Electromagnetic radiation protection of industrial scientific and medical equipment, daily necessities, microwave ovens, cell phone electromagnetic radiation protection and many other aspects. [Page]
4 Nano Stealth Coatings
Stealth coatings are stealth materials that are fixed on the structure of the weapon system, and can be divided into radar stealth coatings, infrared stealth coatings, visible light stealth coatings, laser stealth coatings, acoustic stealth coatings and multi-functional stealth coatings, etc. According to their functions. Nanocoatings are generally made of nanomaterials and organic coatings, which should be called nanocomposite coatings in a more scientific way. After decades of development, stealth coatings, as one of the key technologies of stealth technology, has not only been used for flying missiles and other aircraft, the latest development is that several major industrialized countries and military powers have begun to stealth coatings technology applied to naval vessels, stealth armored vehicles, stealth mines, stealth artillery, stealth tanks, stealth vehicles, stealth radar, stealth communication systems, stealth engineering, stealth fortifications, stealth robots, stealth combat suits and infrared stealth flares on technical equipment.
Nanomaterials in ship coatings applied in the following areas: ① absorption of radar waves coating. ② ship infrared stealth coating: nano alumina, iron oxide, silicon oxide and titanium oxide composite powder and polymer fibers combined with the mid-infrared light band has a strong absorption properties, this composite has a good shielding effect on the infrared detector of the band, both excellent absorption of radar waves, but also good absorption and dissipation of infrared performance, with obvious stealth function. ③ Submarine camouflage coatings: the technical key of submarine camouflage coatings is the wet reflectivity and aging resistance of the coatings. The application of nano-scale dark pigments is one of the effective ways to reduce the wet reflectivity and improve the aging resistance of camouflage coatings. ④ Super weather-resistant hull paint: nano titanium dioxide has the property of absorbing ultraviolet rays, which can improve the aging resistance of coatings. They can be one of the additives for future main development. ⑤ Anti-mold coatings in ship cabins: nano-materials such as nano-titanium dioxide and nano zinc oxide can be used as antimicrobial agents that are non-toxic to human body, have a wide range of antimicrobial activity, and have excellent thermal stability. The antimicrobial effect of nanomaterials can be used to prepare new and efficient anti-bacterial and anti-mold materials and coatings in cabins. (6) New and efficient anti-fouling coatings for ship bottoms: the use of nanoscale anti-fouling agents, such as nano-copper oxide, nano zinc oxide, etc., or the use of microencapsulation technology may be an effective way. (vii) Ship fire-retardant materials and coatings: certain nano-particles have fire-retardant function, such as nano zinc oxide can be added as a fire retardant to the ship cabin interior decoration materials or formulated into fire-retardant coatings, to improve the fire resistance of the ship's non-metallic decorative materials and fire-retardant coatings.
5 Automotive Coatings
Automotive coatings include coatings used in the manufacture and maintenance of automobiles, and the main varieties are automotive primer, automotive topcoat, overprint varnish, automotive intermediate coatings and automotive refinishing paints. Automotive coatings have become a specialized coating. In the automotive industry in developed countries, the production of automotive coatings accounted for about 20% of the total output of paint.
5. 1 Primer
The vast majority of automotive primers in the world use cathodic electrophoresis paint, and the direction of future development of cathodic electrophoresis paint is high durability, high transmittance, low pigment content, low VOC, low odor, low fuming, no heavy metals, less CO2 generation, light weight, energy saving and so on. Lead-free cathodic electrophoretic coatings, low-temperature curing electrophoretic coatings have been applied in Europe, America and Japan.
5. 2 medium paint
Putty, two primer and sealer are the middle layer of the matching coating, that is, medium paint. The focus of the development of intermediate paints and topcoats is on waterborne coatings, powder coatings and high solids coatings.
5. 3 top coat
Automotive top coat in the whole coating system plays a major role in decoration and protection, determines the durability and appearance of the coating. At present, some western developed countries in the new automobile coating line, has been used in the water-based automobile top coat, basically the domestic still mainly use solvent-based top coat. The main varieties of automotive topcoat is magnetic paint, generally with bright colors, good mechanical properties and weather resistance.
5. 4 Metallic glitter primer
The so-called metallic glitter primer is the paint used as the coating between the medium coating and the overcoat varnish layer. Its main functions are coloring, covering and decoration. Metallic glitter primer has this special decorative effect because of the addition of metallic aluminum powder or pearlescent powder and other effect pigments in the paint.
5. 5 Plastic coatings
Automotive plastic coatings are similar to other coatings for metal parts, and are also divided into primer, primer, varnish or topcoat.
5. 6 Damping coatings
In recent years, automotive damping coatings are generally made of polyvinyl chloride resin (PVC) as the main base material for a solvent-free PVC series of coatings, whose solid content can generally reach 100%. This PVC coating has good hardness, elongation, shear strength and tensile strength, can well meet the performance requirements of the damping coating.
5. 7 Powder Coatings
Automotive powder coatings have epoxy-polyester hybrid, polyester, polyurethane and acrylic and other types. In the future, the development of powder coatings for automobiles will work on further improvement of weather resistance, UV resistance, low temperature curing, thin film and decorative properties.
5. 8 Application of nanomaterials in automotive coatings
The application of nanomaterials in automotive coatings mainly includes nano top coatings, nano glass coatings, collision discoloration coatings, anti-stone strike coatings, anti-static coatings, deodorant coatings and so on. Utilizing its special properties, the development of automotive coatings with excellent performance has a broad development prospect.
6 Other new coatings
6. 1 Anti-skid coating
Naval aircraft deck anti-skid coating mainly refers to aircraft carriers, large expulsion ships and other warships landing planes and parking planes equipped with a unique anti-skid coating. According to the different materials used, can be divided into resin-based anti-skid coating and metal-based anti-skid coating; according to the different coating methods can be divided into spray deck anti-skid coating and roller coating deck anti-skid coating.
6. 2 submarine features signal control coating [Page]
Submarine acoustic features control technology is a comprehensive application of technology. Acoustic stealth coatings have a damping effect, sound insulation, anechoic effect, there are sound insulation materials, anechoic materials polyurethane acoustic stealth coating.
6. 3 new photocatalytic coatings
The Institute of Physical and Chemical Technology of the Chinese Academy of Sciences has recently successfully developed a new type of photocatalytic coatings at the same time with antibacterial, anti-fog, self-cleaning, photocatalytic decomposition of pollutants, and other multiple effects. The main functional component of the coating is TiO2 and its silver complex. This coating can be used on the surface of various materials such as glass, ceramics, plastics, etc., and can provide these materials with multiple functions such as antimicrobial, anti-fogging, anti-mold, self-cleaning, and photocatalytic decomposition of pollutants. Therefore, this coating can be used in various applications such as automobile mirrors, automobile glass, glass curtain walls, road traffic signs, billboards, car bodies and train bodies. The Institute of Physics and Chemistry has applied for a national invention patent for this technology.
6. 4 new purification of automobile exhaust paint
Britain's Happy Times Chemical Company recently invented a paint, this paint coated in the exhaust pipe of the car, can absorb most of the harmful gases in the car exhaust. In addition to purifying automobile exhaust, the company hopes the coating will become a new weapon for construction engineers and urban planners to eliminate environmental pollution. The coating is a polysiloxane-based coating, which is distributed with a large number of titanium dioxide and calcium carbonate spherical particles with a diameter of about 30 nm.
6. 5 New Coating to Protect Discs from Wear and Tear
El This TDK company has developed a new type of coating for optical discs that is highly resistant to wear and tear. CD, DVD and other optical discs using this coating, can effectively eliminate the surface of the disc after the wear and tear of the data can not be read out of the pain. The new coating utilizes a two-layer production process. TDK said that this new coating is not only tougher than the company developed two years ago, single-layer coating, and in the visible light range is transparent, can be very good to protect the surface of the color LCD screen from damage.
6. 6 new room temperature reversible color change coating
A kind of cobalt salt as the color change crystal, water-absorbent material for the water vapor balance agent of the color change coating. This coating can effectively overcome the environmental humidity, film-forming materials on the color change point temperature, the color change point of the color change coating can be limited to 30 ~ 32 ℃. At the same time, the addition of other inert pigments can be formed with a variety of harmonic color of the color-changing coatings.
6. 7 new thermal protective coatings
The study of a supersonic vehicle for external thermal protective coatings. Thermal protective coatings should have the characteristics of low density, low thermal conductivity, high specific heat capacity, low pyrolysis temperature, high latent heat of pyrolysis, high gasification fraction, high specific heat capacity of pyrolysis gas, high radiation coefficient and good adhesion with the surface of the vehicle. Phenyl silicone resin modified E-type epoxy has good performance, and its coating material as a substrate has better performance.
6. 8 thermal barrier coating and sol-gel coating
At present, the most feasible and economical way to improve the operating temperature of the gas turbine is to use advanced high temperature alloy materials and cooling technology under the premise of the thermal barrier coating. The use of thermal barrier coatings can reduce the transfer of heat from the gas to the metal parts, so that the working temperature of the metal parts can be reduced by 50 ~ 80 ℃, and can be reduced by 140 ℃ in a short period of time. The thermal barrier coating consists of two parts: the inner layer of oxidation-resistant alloy layer (middle layer) and the outer layer of insulating ceramic layer (surface layer).
Sol-gel coating technology applied to metal surfaces, giving the metal surface higher oxidation resistance, corrosion resistance, etc., has a wide range of application prospects. With the development of sol-gel coating technology and control technology, it will make a greater contribution to improving the corrosion resistance of metals.
7 Conclusion
Development of environmentally friendly anti-fouling coatings is one of the 21st century marine coatings development direction, non-toxic low-surface-energy anti-fouling coatings, tin self-polishing anti-fouling coatings, a wide range of biomimetic anti-fouling coatings will be the focus of the future development of the development of a new type of marine anti-fouling coatings technology is imperative. It is believed that the commercialization and practicalization of new anti-fouling coatings will not be far away. As nanomaterials have good wave-absorbing properties while also having the characteristics of wide bandwidth, good compatibility, low surface density, and thin coating, the United States, Russia, France, Germany, Japan and other countries have taken the nanomaterials as a new generation of stealth materials to be researched and explored. From the market point of view automotive coatings is one of the development focuses of the whole coating industry. The development and application of some new coatings have enriched the types of coatings and contributed to the development of the coating industry. Basic knowledge of paint
Attached
I. Definition and role of paint
Definition: commonly known as paint, is a coating on the surface of the object after a certain period of time after the physical and chemical reaction changes, the formation of adherence to a solid, with a certain degree of strength, a continuous solid film.
Role: protective effect, decorative effect, color marking, special role
Two, the composition of the paint
Main film-forming substances: natural resins, vegetable oils, man-made, synthetic resins
Secondary film-forming substances: pigments (coloring, rust, special), functional materials
Supplementary film-forming substances: solvents, auxiliary, catalysts, etc.
Three, the coating is commonly known as paint, is a kind of coating on the surface of the object for a certain period of time physical and chemical reaction changes to form an adhesive firm, continuous solid film. p>
Third, the classification of coatings
Classification by form: solvent-based, solvent-free, water-based, powder
Classification by use: construction, leather, paper, wood
Classification of film-forming mechanism: water emulsion, plastic melt, volatile
Classification of the construction process: primer, putty, two primer, topcoat
By the film performance Classification: insulation, anti-rust, wear-resistant, anti-corrosion
Classification according to film-forming substances: epoxy resin, natural resin, alkyd resin
Four, classification of marine coatings
Marine workshop primer
Below the waterline paint: the bottom of the ship antirust, anti-fouling paint, marine antirust paint
Beyond the waterline paint: marine waterline paint, paint the hull of the ship, deck paint, Cargo hold paint, cabin interior paint
Tank coatings: drinking water tank paint, ballast tank paint, oil tank paint, cabin bilge paint
Section II: Ship coating process
Ship coating process mainly includes steel surface descaling and painting two work
A, steel surface descaling
1, hand-operated descaling (use simple tools or small machinery) Descaling tools to remove rust such as wind grinding tools)
2, sandblasting (pill) descaling
3, chemical descaling
4, shot blasting descaling
Two, painting
1, air spray paint
Principle: compressed air from the center of the hole in the air cap sprayed in the paint nozzle to form the front of a negative pressure zone, so that the paint sprayed from the nozzle Into the high-pressure airflow area, the rapid diffusion of fog flying to the surface of the coated object.
Method: Using a variety of spray guns to carry out operations
Features: high efficiency of paint application, adaptability, good film quality, low paint utilization (50%), pollution of the environment.
2, high-pressure airless spray paint
Principle: not with the help of compressed air spray to make the paint atomization, but to the paint to apply high pressure to make it spray atomization.
Method: the use of airless paint spraying equipment for operations
Features: high paint efficiency (more than 3 times higher than the air spraying), a wide range of adaptability to the viscosity of the paint, paint film quality is good, high utilization rate of the paint, and pollution of the environment is small.