Coating knowledge: traditional anticorrosive coatings and their protection mechanism

Core tip: as the second largest paint category in the paint field, anticorrosive paint has a long history of development and a wide range of product structure For a long time, anticorrosive paint has been the focus of the paint industry Anticorrosive coating has a long history It can be said that the development history of anticorrosive coating products is a miniature of the development history of coating products 1 Epoxy resin anticorrosive coating has excellent adhesion to metal, concrete, wood, glass and so on This is because its molecules contain polar hydroxyl, ether bond and so on Even wet to wet, it has certain adhesion Some resins, such as unsaturated polyester, cure with a volume shrinkage plane of 1 Shenyang steel structure fireproof coating construction expert punde Building Fire Engineering Co., Ltd Recommended introduction: since its establishment, Shenyang punde Construction Fire Engineering Co., Ltd has cultivated a group of professional construction teams with excellent equipment, rich experience and serious responsibility with advanced and scientific management methods and strict engineering quality assurance and after-sales service system It has undertaken a number of fire system installation projects, which has been praised by customers Every idea and special requirement of you will be fully considered by us and fully realized in the construction technology, which will become the cornerstone of our successful long-term development We are looking forward to your invitation, to provide you with quality services and high-quality technical support! All construction coatings have passed ISO9001 Home of coatings: as the second largest coating category in the coating field, anticorrosive coating has a long history of development and a wide range of product structure For a long time, anticorrosive coating has been the focus of the coating industry Anticorrosive coating has a long history It can be said that the development history of anticorrosive coating products is a miniature of the development history of coating products 1 Epoxy resin anticorrosive coating has excellent adhesion to metal, concrete, wood, glass and so on This is because its molecules contain polar hydroxyl, ether bond and so on Even wet to wet, it has certain adhesion Some resins (such as unsaturated polyester) have a volume shrinkage plane of 11% when cured, resulting in high internal stress and reduced adhesion The volume shrinkage of epoxy resin is only about 2%, and the ether bond in the epoxy molecule makes the molecular chain soft and easy to rotate, which can eliminate the internal stress, so the adhesion is high The epoxy resin contains hydrophilic hydroxyl and ether bond, together with the amine group in the curing agent, they will affect the water resistance of the film, but the bisphenol a chain segment in the resin has hydrophobicity, the rigidity of the two benzene rings shields the hydroxyl and ether bond, maintaining the water resistance of the whole film The glass transition temperature of cured epoxy resin is higher, which is beneficial to its water resistance There is no ester bond in epoxy resin, so it has good alkali resistance The cathode of the corrosion micro battery is alkaline, and the common oil paint or alkyd paint is easily saponified It can be said that epoxy resin coating has the necessary alkali resistance and adhesion for excellent anticorrosive coating 2 Polyurethane anticorrosive coating polyurethane anticorrosive coating is generally a two-component formula, one containing isocyanate NCO and the other containing hydroxyl In the process of construction, the two components are mixed to react and solidify to form polyurethane Polyurethane anti-corrosion coating is similar to epoxy coating in nature, can be mixed and cross-linked in the room, and the paint film can be resistant to oil, salt solution and other impregnation, with excellent anti-corrosion performance; it can also be made into solvent-free paint, or high solid paint, with thick film in one construction; it can be made into powder paint; It can be mixed with coal tar pitch to produce anti-corrosion coating with salt water resistance and low price (but black color and lack of decoration) 3 Coal tar pitch coating asphalt is an important raw material of anti-corrosion coating, which can be divided into petroleum asphalt, natural asphalt and coal tar pitch The water absorption of the first two kinds of Asphalt Coatings is higher than that of the coal tar asphalt coating, so the coal tar asphalt coating is the most important one in the field of anti-corrosion, with excellent corrosion resistance Coal tar pitch is aromatic, the ratio of carbon atom to hydrogen atom is more than 1.4:1, so the water resistance is better, while the ratio of carbon atom to hydrogen atom is about 0.9:1, the water resistance is worse Therefore, petroleum asphalt can be used for parts with less severe corrosion requirements, such as the bottom of containers Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,