Coating knowledge: precautions for spray coating of waterborne alicyclic epoxy resin

It is suggested that this kind of coating can be constructed by traditional equipment and may replace powder coating What are the precautions for the preparation of water-based alicyclic epoxy liquid coating? Experts from China epoxy Industry Association recently made a special introduction The traditional liquid coating spraying equipment can avoid the investment of basic equipment necessary for a new powder coating line After modification, these coatings can be diluted with water or thickened with cellulose thickener Compared with the traditional diglycidyl ether resin of bisphenol A, alicyclic epoxy has the following areas Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Home of coatings: water-based coating is made of caprolactone polyol without VOC and haps resin and narrow polymerization degree distribution This kind of coating can be constructed with traditional equipment and may replace powder coating What are the precautions for the preparation of water-based alicyclic epoxy liquid coating? Experts from China epoxy Industry Association recently made a special introduction The traditional liquid coating spraying equipment can avoid the investment of basic equipment necessary for a new powder coating line After modification, these coatings can be diluted with water or thickened with cellulose thickener Compared with the traditional diglycidyl ether resin of bisphenol A, alicyclic epoxy has the following differences: it is the main chain of aliphatic group and reacts rapidly with acid, but it does not react with the common curing agent of amine / amide epoxy basically, it does not contain chlorine, the viscosity is 350 centipoise, while the diglycidyl ether resin of bisphenol A is 11000 centipoise, and it also has excellent weather resistance The application of low viscosity alicyclic epoxy in cationic UV coatings has increased significantly There are many reports about the preparation and properties of this kind of 100% solid coatings without "VA", but there are few detailed documents about its application in heat curing coatings In principle, the formulation and technical know-how of cationic UV coating can also be used in the thermal curing system, but they are also different Generally, UV coating does not need spraying construction, so the construction viscosity can be higher than spraying thermal curing coating, and the water in baking cationic coating can be used as the diluent of VOC Caprolactone polyol is an effective active diluent used in solvent based coatings and can accelerate the curing of cationic UV coatings In cationic UV coatings, the hydroxyl group of such polyols can accelerate the curing and cause a certain curing sensitivity to humidity In the heat curing coating, because of the low humidity in the oven, moisture does not inhibit the curing The presence of polyols increases the tolerance of water, so water can be used as a VOC free diluent in the paint formulation composed of alicyclic epoxy and polyols, which is actually a high solid organic paint diluted with water There are two advantages of water dilution: low viscosity without VOC, common and well-known measures of water-based paint can be used to achieve anti sagging and rheological control As the components in the formula are only partially miscible with water, the amount of water that can be absorbed is limited, and it should be avoided to add too much water to cause phase separation Cellulosic thickeners can effectively control sagging in water-based coatings, but it is not clear whether they are effective in 100% solid, water diluted alicyclic epoxy coatings Early work showed that the water diluted 100% solid epoxy had thixotropy when measured by Brookfield viscometer The investigation of various thickeners shows that cellulose thickeners have the best comprehensive properties When heated to 40-60 ℃, the spray gun can be used to obtain the best appearance of the paint film, and low construction temperature can make the solidified paint film produce more orange peel Experts from China Epoxy Resin Industry Association said that the main advantage of powder coating is high coating efficiency High coating efficiency is mainly achieved through the recovery of powder To be equivalent to powder coating, such liquid coating needs some way to recover flying paint Because the paint formula mentioned here does not contain organic solvent, it is much easier to recover If necessary, the water can be used to adjust the water lost in the recovery process by measuring the conductivity Compared with the relatively high baking temperature required for powder paint, the baking temperature required for this kind of paint is lower, which can save energy Another scheme under evaluation is to use "unicarb" method to spray the anhydrous epoxy, polyol and pigment composition formula products The application of "unicarb" method is more efficient than that of powder coating If VOC free coating is not needed, simply add solvent into the above formula As for the formula, experts from China epoxy Industry Association said that all additives and rheology control agents must be free of alkalinity due to the termination of curing due to alkali, and alkali pigments and amine treated pigments will inhibit curing If the paint film is too thick or the oven is not ventilated, the amine can not be completely separated from the paint film to inhibit the curing Viscosity increases with the increase of polyol branching degree: the viscosity of diol is lower than that of ternary or quaternion alcohol When it is used with diol, it needs to increase the amount of epoxy with high corrosion resistance The increase of catalyst will accelerate the curing speed but also reduce the corrosion resistance The molar ratio R of epoxy and hydroxyl has a significant impact on the curing speed In short, alicyclic epoxy and caprolactone polyols can be used to prepare low viscosity or VOC free coatings The coatings can be diluted to spraying viscosity with water Cellulose thickener can give 100% solid epoxy and polyol coatings diluted with water to effectively prevent sagging The curing speed of the system is determined by the following variables: molar ratio of epoxy to hydroxyl, functionality of polyol and epoxy, and catalyst The dosage of chemical agent and curing temperature, the formula can be easily used to prepare color paint, because this kind of paint is cationic curing, so basic pigment and substrate will inhibit curing 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,