Paint knowledge main types of anticorrosive coatings

Core tips: introduction to the knowledge of industrial paint - Features - Classification chapter: mainly introduces the types and classifications of anti-corrosion coatings, as well as the use characteristics and precautions of anti-corrosion coatings The main types of anti-corrosion coating 1 Grease coating grease coating is a kind of coating with dry oil as the main film-forming material It is characterized by easy production, good brushing performance, good wettability to the surface, low price, and flexible paint film; however, the paint film is slow drying, soft film, poor mechanical performance, acid and alkaline resistance, water resistance and organic solvent resistance Dry oil is often combined with antirust pigment to form antirust paint, which is used in atmospheric environment with low corrosion resistance requirements 2 Lacquer lacquer Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Home of coatings news: introduction to industrial paint knowledge - Characteristics - Classification chapter: mainly introduces the types and classification of anti-corrosion coatings, as well as the use characteristics and precautions of anti-corrosion coatings The main types of anti-corrosion coating 1 Grease coating grease coating is a kind of coating with dry oil as the main film-forming material It is characterized by easy production, good brushing performance, good wettability to the surface, low price, and flexible paint film; however, the paint film is slow drying, soft film, poor mechanical performance, acid and alkaline resistance, water resistance and organic solvent resistance Dry oil is often combined with antirust pigment to form antirust paint, which is used in atmospheric environment with low corrosion resistance requirements 2 Lacquer lacquer, also known as national lacquer, lacquer, is one of the specialties in China Lacquer is a kind of milky white viscous liquid from the bark of growing lacquer tree, which is filtered by fine cloth to remove impurities After it is applied on the surface of the object, the color changes rapidly from white to red, from red to purple, and for a long time, it can become a hard and bright black paint film Urushiol is the main component of raw lacquer, the content is 30% - 70% Generally speaking, the higher the content of urushiol, the better the quality of raw lacquer Lacquer has strong adhesion, tough film and good luster It is resistant to soil corrosion, water and oil The disadvantage is that it is toxic and easily causes skin allergy In addition, it is not resistant to strong oxidants and has poor alkali resistance Now there are many modified lacquer coatings, which overcome the above shortcomings to varying degrees 3 Phenolic resin coating mainly includes alcohol soluble phenolic resin, modified phenolic resin, pure phenolic resin, etc The alcohol soluble phenolic resin coating has good corrosion resistance, but its construction is inconvenient, flexibility and adhesion are not good, so its application is limited Therefore, it is necessary to modify phenolic resin Such as rosin modified phenolic resin and tung oil refining, adding a variety of pigments, grinding can be made into a variety of enamel, the film is tough, low price, widely used in furniture, doors and windows coating The pure phenolic resin coating has strong adhesion, water resistance, heat resistance, corrosion resistance and good weather resistance 4 Epoxy resin coating has good adhesion to metal, concrete, wood, glass, etc., and excellent alkali resistance, oil and water resistance and electrical insulation performance But the aging resistance is poor Epoxy anticorrosive coating is usually composed of two components: epoxy resin and curing agent The properties of curing agent also affect the properties of paint film The commonly used curing agents are: ① fatty amine and its modifiers It is characterized by room temperature curable and unmodified fatty amines with high toxicity ② Aromatic amines and their modifiers It is characterized by slow reaction, heat curing and weak toxicity ③ Polyamide resin It is characterized by good weather resistance, less toxicity, good elasticity and poor corrosion resistance ④ Phenolic resin, urea formaldehyde resin and other synthetic resins These resins and epoxy resins are cross-linked to form film after high temperature baking The paint film has outstanding corrosion resistance, good mechanical properties and decorative properties Epoxy ester resin coating is a one component coating system with epoxy ester resin as film-forming material Epoxy ester resin is composed of epoxy resin and vegetable oil fatty acid ester Compared with the general epoxy coating, the cost of the coating is lower and the alkali resistance is poor It is often used as a variety of metal primer and anticorrosive paint for outdoor equipment of chemical plant 5 Polyurethane resin used for anticorrosive coating usually contains two components: isocyanate NCO and hydroxyl When in use, the two components are mixed to react and solidify to form polyurethane Characteristics of polyurethane coating: ① good physical and mechanical properties The paint film is hard, flexible, bright, full, wear-resistant and has strong adhesion ② Excellent corrosion resistance Resistant to oil, acid, chemicals and industrial waste gas Alkali resistance is slightly lower than that of epoxy coating ③ Aging resistance is better than epoxy coating It is often used as a topcoat or as a primer ④ Polyurethane resin can be mixed with a variety of resins, and the formula can be adjusted in a wide range to meet various use requirements ⑤ It can be cured at room temperature or by heating It can also be cured at low temperature (0 ℃) ⑥ The storage stability of the polyisocyanate component is poor, so it must be isolated from moisture to avoid jelly Polyurethane coating has high price but long service life 6 Vinyl resin coating vinyl resin anti-corrosion coating mainly refers to the coating made of vinyl chloride, vinyl acetate, ethylene, propylene and other monomers The perchloroethylene coating has been produced and applied in large quantities Perchloroethylene coating can form a compact film with good chemical corrosion resistance, but it has poor stability to light and heat It should not be used for more than 60 ℃ for a long time and has poor adhesion to metal The raw materials of the coating are abundant and have been widely used to prevent chemical atmospheric corrosion 7 Furan resin coating furan resin coating is resistant to all kinds of non oxidizing inorganic acids, electrolyte solutions, all kinds of organic solvents, alkali resistance is also outstanding, but oxidation resistance is not good Furan resin series anti-corrosion coating includes furfuryl alcohol resin coating, furfural acetone formaldehyde resin coating and modified furan resin coating 8 Rubber coating rubber anti-corrosion coating is made of natural rubber or synthetic rubber after chemical treatment or mechanical processing as film-forming material, plus solvent, filler, pigment, catalyst, etc (1) chlorinated rubber coating The coating has good water resistance, salt water and salt fog resistance, acid and alkali corrosion resistance, and can withstand 10% HCl, H2SO4, HNO3, different concentrations of NaOH and wet Cl2 under 50 ℃ But it is not resistant to solvents, aging and heat resistance are poor The coating is widely used in ships, harbors, chemical industry and other occasions (2) neoprene coating The coating is ozone resistant, chemical resistant, alkali resistant, weather resistant, oil and heat resistant and can be made into peelable coating The disadvantage is poor storage stability; the coating is easy to change color, not easy to make white or light color paint (3) chlorosulfonated polyethylene rubber coating It is prepared by the reaction of polyethylene resin with chlorine and sulfur dioxide (or chlorosulfonic acid) The coating has excellent ozone resistance, remarkable weather resistance, low water absorption, oil resistance and temperature resistance, and can be used above 120 ℃, - 50 ℃ and no brittleness 9 Asphalt coating asphalt is one of the important anticorrosive coatings In particular, coal tar pitch is the best, the price of coal tar pitch coating is low, with the following advantages: ① water resistance, immersion in water for 10 years, its water absorption is only 0.1% - 0.2%; ② resistance to some chemical media erosion; ③ good wettability for the surface of steel not fully derusted; ④ high solid content, thick film can be obtained; ⑤ low price Its disadvantage is brittle in winter and soft in summer and summer Some components volatilize after exposure, which will crack the paint film These disadvantages can be improved by adding some other resins For example, the addition of chlorinated rubber can improve the dryness of asphalt coating, improve the winter brittleness and summer softness; the epoxy asphalt coating made by adding epoxy resin can have the advantages of both asphalt coating and epoxy coating, and obtain very satisfactory effect in anti-corrosion Asphalt coating has been used in container bottom, ship bottom, dock gate, cofferdam and other occasions, with good anti-corrosion effect 10 Heavy anti-corrosion coating heavy anti-corrosion coating is relative to general anti-corrosion coating It refers to the anti-corrosion coating which is several times higher than the general corrosion coating under the severe corrosion conditions It is characterized by excellent corrosion-resistant medium performance, outstanding durability and service life of more than a few years It is mainly used for marine structures and chemical equipment, storage tanks and pipelines At present, the commonly used heavy anti-corrosion coatings mainly include: (1) heavy anti-corrosion zinc rich coating as primer It is divided into three series: thick film organic zinc rich coating, zinc rich precoating primer and inorganic zinc rich coating (2) heavy anti-corrosion intermediate coating and finishing coat This kind of coating can be directly applied on zinc rich primer, mainly including chlorinated rubber system, vinyl resin system, epoxy system, polyurethane system, chlorosulfonated polyethylene system, epoxy tar system and other heavy anti-corrosion coatings (3) heavy anti-corrosion coating for glass phosphorus sheet (4) epoxy mortar heavy anti-corrosion coating (5) fluorine containing coating Such as polytrifluorochloroethylene coating, fluororubber coating, etc 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,