Anticorrosive principle and performance requiremen

2022-10-19
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The anti-corrosion principle and performance requirements of acid and alkali resistant anti-corrosion paint due to alternating anti-corrosion, the anti-corrosion performance should be greatly improved, and its anti-corrosion technical performance should be excellent. It can not only meet the anti-corrosion requirements in corrosive environment, but also meet the performance fatigue requirements of alternating performance. Technical indicators shall be formulated for different anti-corrosion environmental conditions, such as chemical medium resistance, salt water resistance, salt fog resistance, damp heat resistance, oil resistance, mold resistance, atmospheric aging resistance, alkali resistance, potassium resistance, brine corrosion resistance, etc. In addition, acid and alkali resistant anti-corrosion coatings should have good adhesion to the substrate, and the coating film should have good physical and mechanical properties, such as low shrinkage, appropriate hardness, toughness, wear resistance, temperature resistance, etc. The acid and alkali resistant anticorrosive coating can be used under adverse conditions, and has good durability and weather resistance. It can be used under adverse conditions such as ocean and underground for more than 5 or 15 years, even in acid, alkali, salt and solvent media, and under certain temperature conditions, it can also be used for more than 3 years. Zhisheng Weihua company has taken the lead in the scientific research of marine anti-corrosion and acid and alkali resistance anti-corrosion in the world. ZS series of anti-corrosion coatings have excellent anti-corrosion performance and are used in a series of large-scale national projects

acid and alkali resistant anti-corrosion coating due to the particularity of the fixture structure of the tension machine, sometimes it is difficult for us to be sure which kind of fixture is more suitable. The sample is divided into continuous acid resistance or alkali resistance, alternating acid and alkali resistance or simultaneous acid and alkali resistance. The resistance to pH value can be from the corrosion between them. The coating has low aging resistance to alkali and acid and good adhesion

the anti-corrosion principle of the basic anti-corrosion coating mainly includes three aspects: electrochemical principle, chemical principle and physical principle:

1. Electrochemical effect of anti-corrosion:

electrochemical effect of anti-corrosion refers to adding some special substances to the anti-corrosion coating, so that when water and oxygen pass through the anti-corrosion coating, they will react to form anti-corrosion ions, passivate the surface of metals such as steel, and thus prevent the dissolution of metal ions, To achieve the purpose of corrosion prevention, chromate is the most common special substance

2. Chemical principle of anti-corrosion:

the chemical principle of anti-corrosion is to neutralize harmful acid-base substances into neutral harmless substances to protect the materials in the anti-corrosion coating from corrosive substances. Some amphoteric compounds, such as aluminum hydroxide, barium hydroxide and zinc oxide, are often added to Antirust Coatings. These substances are easy to chemically interact with acid-base pests to achieve anti-corrosion effect

3. Physical principle of corrosion prevention:

the physical principle of corrosion prevention is to separate the protected material from the corrosive substances outside with an anti-corrosion coating. The physical principle of antirust coating is to use film-forming agent to obtain a dense anti-corrosion coating to isolate the damage of anti-corrosion to the protected materials. For example, lead soap can be formed after the reaction of lead containing coating and oil to ensure the compactness of the anti-corrosion coating

according to the market demand and the improvement of material properties, Beijing Zhisheng Weihua Chemical Co., Ltd. has experienced many years of development and research, and launched ZS Zhisheng acid and alkali resistant anti-corrosion coating. It is a new inorganic nano polymer deeply synthesized. Silicon carbide, fine-grained alumina, zinc oxide and coating can form an inorganic acid and alkali resistant polymer anti-corrosion coating with physical and chemical dual protection with the surface of the substrate, which is firmly combined with the substrate through chemical bonds, It has no pollution to the environment, long service life and anti-corrosion performance reaching the international advanced level. It is a high-tech replacement product that meets the requirements of environmental protection

the pigments that acid and alkali resistant coatings must have are:

① silicon carbide: it is a high-temperature strength and flexible pressure conditioning method, which can help operators choose their own applicable pressure values. Inorganic non-metallic materials with good wear resistance, acid and alkali resistance, high hardness and good chemical stability. The addition of silicon carbide can greatly improve the bending strength of samples, but in structural design, service performance The utilization range and other aspects have their own characteristics and wear resistance. When there is less matrix between particles, the gap between particles is small, so the structure is compact, the mechanical strength is high, and the wear resistance is also good. Therefore, the addition amount of silicon carbide is an important factor affecting the mechanical performance of acid and alkali resistant anti-corrosion coatings. ② Fine grained alumina: alumina has high melting point, large hardness, excellent insulation performance, stable high-temperature structure and good oxidation resistance, but it also has shortcomings, that is, it is brittle. Therefore, ultra-fine powdered alumina is used to improve the fracture and toughness of acid and alkali resistant anti-corrosion coatings. ③ Zinc oxide: with a hardness of about 4.5H, it is a relatively soft material. Zinc oxide has good thermal stability and thermal conductivity, high boiling point and low thermal expansion coefficient. It is useful in the field of ceramic materials, which can reduce the curing time of acid and alkali resistant anti-corrosion coating and improve the waterproof performance of the coating. Zinc oxide can reflect infrared rays to achieve the effect of heat preservation or insulation. In particular, nano zinc oxide can shield potentially harmful ultraviolet rays, thereby extending the weatherability of the coating. ④ Zhisheng Weihua's unique acid and alkali resistant anti-corrosion coating mutual transmission anti-corrosion solution system increases the adhesion of the coating and the fusion degree of the pigment, and improves the overall initiative and consistency of the coating

at present, the topic of building an energy-saving society has been well known. The latest data from China Institute of electronic information industry development (CCID) shows that in response to national policies, anti-corrosion coatings must be developed in the direction of energy conservation, low pollution and high performance. The development of technology and science is also the requirement of the times: (1) focus on the development of anti-corrosion coatings with high solid content, which is greater than 70% by volume, It is recommended to use low volume agent and solvent-free anti-corrosion paint to make the VOC content in the paint less than 340g/l, so as to ensure the air quality of the construction environment and reduce the emission of harmful pollutants to the atmosphere. (2) Limitation of toxic and harmful components in anti-corrosion coatings. The use of organic volatile substances harmful to human body, such as aromatic hydrocarbons, chlorinated hydrocarbon solvents, heavy metal additives Pb, Hg, CD, Cr, and organic tin irritating oligomer resin to human skin should be avoided in anti-corrosion coatings. Countries around the world and relevant international organizations have made restrictions on some heavy anti-corrosion coatings, such as the elimination of epoxy coal tar pitch coatings; Since January, 2003, the use of self polishing coatings containing organic tin has been prohibited in new shipbuilding; Since 2006, the use of chlorinated rubber coatings containing carbon tetrachloride has been stopped. (3) Develop water-based coatings. In recent years, China's water-based heavy-duty anti-corrosion coatings have been successfully applied in many large-scale steel structure projects. The water-based anti-corrosion coatings of Beijing Zhisheng Weihua Chemical Co., Ltd. have been in the forefront of the world, with leading technology and high scientific and technological content. Most of the technologies are specific. Zhisheng brand water-based anti-corrosion coatings have high temperature resistance and no volatile substances. However, the water-based anti-corrosion coating accounts for about 6% of the anti-corrosion coating market, and the primer is mainly used. As the development direction of anti-corrosion coating, the research of water-based heavy-duty anti-corrosion coating must be strengthened to make a breakthrough in anti-corrosion performance, surface treatment grade requirements and construction performance, and gradually meet the increasing needs of the market for water-based heavy-duty anti-corrosion coating

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