Application cases in the field of water-based polyxyl nanocoated and heavy metal corrosion

With the full implementation of the environmental tax in 2018, traditional solvent-based anti-corrosion coatings have been unable to meet the requirements of the new situation. In the field of water-based industrial coatings, how to improve product performance, optimize product coating, expand the scope of application has become an industry problem. At present, the domestic water-based industrial anti-corrosion coatings are currently basically used in C3 and below the medium-corrosion environment, C4 and above corrosion environment in the field of heavy anti-corrosion engineering use of engineering cases are very few, to the promotion and application of water-based industrial coatings brought great difficulties .
Chemical Research Institute Co., Ltd. recently developed water-based nano-heavy anti-corrosion coating technology has been in the chemical heavy anti-corrosion pipe gallery and other projects to promote the application. The technology greatly improves the comprehensive performance of environmentally friendly anti-corrosion coatings, is the latest industrialization in the field of domestic water-based coatings, has reached the anti-corrosion properties of traditional solvent-based heavy anti-corrosion coatings, and has played a benchmark role in promoting the environmental protection process of "oil-to-water" coatings in China.
coating is suitable for steel, concrete and other substrates, showing excellent corrosion resistance. Products have different colors, resistant to strong acids, strong alkalis, high salt erosion, oil corrosion, anti-fouling, a wide range of applications. 2018 new design anti-corrosion coating production capacity of 1,000 tons of production line, 2019 new design anti-corrosion coating production capacity of 5,000 tons of production line. Products in line with the national level chemical sector industry strategy, heavy anti-corrosion coatings and intelligent coating materials for the Group and the national energy and fine chemical industry major safety escort. "Anti-corrosion third generation" products lead the development of the industry, enhance the influence of domestic coatings in the world anti-corrosion industry, promote the anti-corrosion industry technological progress and coating industry structure optimization and upgrading, promote the sustainable development of the industry.
According to the National Coating Quality Supervision and Inspection Center and other related tests, the coating wear resistance 0.02 g, permeability 0.1mL/24h, combustion performance B1 level, salt spray resistance 3000h, Shore hardness 61, VOC content 72g/L, pressure strength 132MPa, the results in Shenyang Economic and Technological Development Zone to achieve industrialization transformation.
This water-based nano-heavy anti-corrosion coating breaks the traditional heavy anti-corrosion coating bottom, medium and surface coating methods, coating nano-in-place generation of inorganic hybrid particles, to achieve organic-inorganic hybrid assembly control technology. In this composite material, there are units to improve adhesion and toughness, inormeric nanoparticles show physical shielding and hardness, compared to traditional commercially available products, the material's ultra-high hardness makes it difficult to pass the corrosion media such as H-, OH-, Cl-, overcoming the shortcomings of the traditional epoxy coating is not resistant to aging, low hardness, overcoming the polyurea coating curing fast, poor adhesion and other shortcomings. The problem of nanoparticle dispersion and reunification in coating is overcome, and the controlled distribution assembly of organic-inorganic multi-phase mixed components is realized.
Water-based polyphur coating has been applied to chemical metal pipe gallery, reactor outer wall, reactor lining, concentrated separation tower, neutral tank lining, neutralizing kettle lining, hydrochloric acid kettle outer wall, etc., the implementation of the "SH3022-2011 petrochemical equipment and pipeline coating corrosion prevention technical specifications", can be in the same quality premise, the realization of petrochemical and other metal heavy anti-corrosion coating water and simple construction.
application case of water-based polysaccharide coating
new chemical pipe corridor metal corrosion
case one, a chemical plant pipe corridor newly built, construction area of 10000m2. Corrosive medium: organic solvent. Workshop prefabriading, on-site assembly frame installation, use 1 year intact. Sprayed with single-part primer and two-part paint. Environmental protection low VOC, cover gloss is very good, smoothness is good, plus thickness is easy, adhesion is good, hardness is relatively good, water resistance to aging, good elasticity.
must be sprayed within 4 h of the end of the blast, otherwise the batch of individual steels will need to be reseeded to SA2.5. The air conditions before painting require relative humidity of <85%, steel plate temperature ≥10 degrees C, dew point temperature is less than 3 degrees C or more. The primer needs to be repaired after drying and in an imperfect position. The back of the steel must be completely finished with the construction primer before the next procedure. The paint must pass the inspection before it can be constructed. The groove position and the position where it is difficult to ensure the thickness of the film are pre-coated at least 1 time, at least 50 m. After the coating is fully cooked, use a roller brush, die-end use plate brush, or even elbow brush. The film is ≥ to 100 m, but not more than 300 m. If the pre-coated film thickness is not enough, the sand treatment and cleaning continue to be applied to meet the requirements, if the specified film thickness, then a small amount of area can be polished to make it meet the requirements, a large number of areas need to be re-sanding treatment.
film thickness depends on the solid content of the coating, the dilution of the thinner, the pressure size, the gun nozzle model, the worker skills and other factors. However, according to the site test 100 m primer film thickness requires workers to press the gun 3 times. The scene environment is affected by many factors, such as 3 times the pressure gun still does not meet the membrane thickness requirements, will continue to press the gun to meet the required film thickness requirements. Primer and finish cleaning using scraper treatment flow hanging, more than 100 m sandpaper treatment surface uneven position and scraper treatment residual position, cleaning standard level 3. Correct selection of sandpaper, the correct number of items, the use of the environment should be good: such as gray, wind, rain, workers. Primer repair construction, reference drying curve, according to the best time for drying. Use a primer to stir mechanically, not manually. If stirred manually, it may cause uneven mixing, after construction will appear dry conditions.Figure 4 Wet film is not leveling, flow hanging
Figure 5 dry film local pinhole map 6 open environment spraying construction
The cause analysis of the abnormal phenomenon may be: the flow hanging problem is due to the two-part spray gun is too close, the leveling problem also needs to adjust the formula. Plant ground open environment spraying construction (Figure 6), pinholes due to high air pressure caused. The construction party did not blast the substrate, the primer has dew rust. Rust at welding and corrosion at paint film at lifting.
the maintenance of pipe gallery metal anti-corrosion
case II, a chemical plant pipe gallery secondary maintenance, an area of 2,000 m2. Corrosion media: organic solvents. Original coating alicic paint film, service time of 1 year. The use of maintenance program: roll-on primer and two-part paint spray, after 1 year of use intact.
chemical pipe gallery belongs to the secondary maintenance, involving high-altitude operation, the construction difficulty factor is large. All primer surfaces should be blasted or hand-tooled to remove surface contaminants before coating is patched. Locally contaminated areas should be cleaned with suitable cleaning agents or solvents in accordance with SSPC-SP1 standards and methods.
when the temperature is below 0 degrees C or above 40 degrees C (except as specified in the special provisions) corresponding measures must be taken to improve the environment, to achieve the paint product description of the construction of environmental conditions. When the relative humidity ≥ 85% or the surface temperature is below the dew point of 3 degrees C, it cannot be applied for construction. Special reminder is the paint construction, when the relative humidity in 80% or less when the curing effect is satisfactory, relative humidity is low, when coating and coating after the appearance of water vapor condensation, will lead to the surface loss of luster, if there is water, will lead to color change, in dark paint surface and low temperature conditions are particularly obvious. Therefore, it is suggested that paint construction should choose the good weather or in the workshop or rain shelter construction. When spraying, the distance between the spray gun and the coated component is controlled between 30 and 40 cm, and the spray gun should be perpendicular to the spray surface. The re-injection of the gun should be controlled between 0.8 and 1.0m, otherwise it is easy to produce waste or paint fog.
metal kettle outer wall corrosion
case III, metal reactor outer wall protection secondary maintenance, corrosion media: hydrochloric acid, volume 5 m3. Using manual substrate treatment, spray primer and spray paint, after 1 year of use intact. Under the same conditions, the experimental group used epoxy coating to sell products on the market, after 1 year of severe corrosion.
substrate treatment is the key to protection, large-scale equipment is not easy to use, the site using manual angle grinding substrate treatment, rust completely removed, to avoid rainy weather suggested immediate construction primer, dry after construction paint. In this case, there is a drip of hydrochloric acid liquid, the overall corrosion environment is hydrochloric acid. Paintman has the risk of hydrochloric acid liquid medium drip, it is recommended to do a good job of protective equipment.
metal kettle inner wall corrosion
case IV, metal reactor inner wall protection secondary maintenance, corrosion media: sodium hydroxide, volume 30 m3. Using manual substrate treatment, roll-on primer and roll-on paint (Figure 13), after 1 year of use intact.
Water-based polysaccharide nanocoat is simpler than traditional epoxy glass and steel construction process, short construction cycle, fast film forming, high adhesion, high resistance to high strength, strong acid, strong alkali, salt, industrial wastewater, domestic sewage, seawater, all kinds of solvents. Traditional epoxy glass steel is susceptible to pitting, corrosion medium into the interface, metal corrosion into oxidizing skin, easy to bubble caused epoxy glass steel pieces to fall off (Figure 14).
In conclusion
the coating in Liaoning Province in 2018 has been widely used, has been applied to the new chemical metal pipe gallery, maintenance of metal pipe gallery, metal kettle outer wall, metal kettle inner wall, the inner and outer wall of the metal kettle, the inner wall of the concentrated separation tower, anti-corrosion pool and biochemical pool, production workshop floor, etc., anti-corrosion protection performance outstanding, has been recognized by customers. Coating is suitable for spraying, rolling coating and other construction methods, while ultra-strong anti-corrosion performance has become the industry's new favorite. The application of water-resistant coatings to heavy corrosion prevention has been initially recognized by customers and will promote the green development of industry innovation.