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Antiseptic coating used crosslinking agent
2017-7-2 23:49:31
Antiseptic coating used crosslinking agent
In this paper, the corrosion mechanism of waterborne polyurethane anticorrosion coating and classification are briefly described, mainly introduced the research status of modified waterborne polyurethane anti-corrosion coatings, and the latest progress and the development trend and application prospect is discussed.
Metal materials with excellent mechanical and process performance has an important role in the field of materials, but the loss caused by metal corrosion to humans is staggering, global economic loss caused by corrosion of about $1 trillion a year, accounts for about 10% of gross output value of all the year round.
Therefore, it is of great scientific significance to study the corrosion protection methods of metal to control the corrosion of metal and reduce the loss caused by corrosion. There are many methods to prevent metal corrosion, such as metal selection, cathodic protection, metal protection, corrosion inhibitor and anticorrosion coatings.
In all anti-corrosion measures, anti-corrosion coatings are the most widely used, economical and convenient methods. The coating anti-corrosion has many advantages, such as easy construction, wide applicability, coating maintenance and repainting, low cost and lower construction cost.
In many anticorrosive coatings, polyurethane coating is the most common coating after other anticorrosive coatings, and is second only to alkyd resin coating. Affected by factors such as oil resources, environmental protection laws and regulations, the world constantly to improve the performance of coating anticorrosive coatings industry at the same time, the development of pollution-free or less pollution and excellent coating species has become an important developing direction of anticorrosive coatings.
Anti-corrosion, low temperature curing waterborne polyurethane has outstanding resistance to oil, and salt water resistance, abrasion resistance, impact resistance, resistance strain, such as performance, is a kind of excellent comprehensive performance and good prospects for development of coating anticorrosive resin.
But due to the water as dispersing agent, waterborne polyurethane containing hydrophilic group, the coating resistant to water, chemical resistance and solvent resistance is poorer, to achieve the anticorrosion performance, need to be modified.
The commonly used modified materials are epoxy resin and acrylic resin. Besides the epoxy group, epoxy resin contains hydroxyl groups, which can directly participate in the synthetic reaction of waterborne polyurethane. Acrylate contains hydroxyl groups, which are modified by copolymerization or blending. This paper mainly introduces the research status and recent progress of modified waterborne polyurethane anticorrosive coatings.
Anti-corrosion mechanism of waterborne polyurethane anticorrosion coating: shielding isolation of coating
Organic anticorrosive paint is coated on the surface of the body, and the coating's shielding is to insulate the substrate and the environment so as not to be corroded. According to the principle of electrochemical corrosion, metal corrosion is caused by the presence of water and oxygen in the metal interface and the way of ion circulation.
Chinese name: Diethyl toluene diamine(DETDA)
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
Therefore, to prevent the corrosion of metal, it is required that the coating has a shielding effect, which can prevent water and oxygen from being penetrated by the external environment and reach the metal interface. Inorganic pigments such as glass scales and aluminum powder added to the coating can enhance the shielding isolation of the film.
Coating corrosion and passivation: usually contains corrosion and passivation role in anti-corrosion coating of chemical type of antirust paint, with the metal surface, such as passivation, phosphorization, generate new surface membrane layer, such as passivation membrane, phosphating film. The electrode potential of these films is positive compared with that of the original metal, so that the metal surface partially or completely avoids the possibility of becoming an anode.
At the same time, because there is a lot of micro space on the film, it is convenient for the membrane material to attach, which can prevent the rust from spreading out in the direction of the destruction of the film.
Low energy consumption, radiation crosslinking acrylic paint does not need high temperature baking low on air pollution, crosslinking time, in seconds, short lines, coating performance is good, infrastructure investment is large, short pot life coating cost is high. Water-soluble acrylate paint requires the construction humidity to be between 30 and 70 %.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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