Formulation design has a great impact on waterborne epoxy coatings

What is the performance of waterborne epoxy coatings in the end? China's epoxy resin industry association experts believe that many factors play a role, must not ignore any of them. Formulation design of water-based epoxy paint a huge impact, is one of them.

Experts said that through the epoxy resin, water-based epoxy curing agent, pigments and fillers and a variety of additives to choose the performance of different water-based epoxy resin coating, in the design of water-based epoxy resin formulations need to consider two Factors: First, epoxy resin and water-based epoxy curing agent equivalent ratio, the second is the choice of pigments and fillers, the third is the choice of additives. These three factors to consider the whole, the formula design will be successful.

The equivalent ratio of epoxy resin to waterborne epoxy curing agent is the primary factor. China epoxy resin industry association experts said that this aspect due to the type of water-based epoxy resin coating is quite different: for type Ⅰ water-based epoxy resin system, because it is water-based epoxy curing agent direct emulsification of low molecular weight Liquid epoxy resin, the system has a high surface activity of the chain, the appropriate increase in the equivalent ratio of the two can significantly improve the water resistance and hardness of the coating, the general control in the theoretical value of 5 to 10% Inside. For other types of waterborne epoxy resin system, if the appropriate increase in the amount of epoxy resin, help to improve the water resistance and corrosion resistance of the coating, it is because the epoxy resin is lipophilic, and water-based epoxy curing agent Of the hydrophilic strong, appropriate to reduce the water-based epoxy curing agent can improve the system's lipophilicity. In some cases, if the use of epoxy curing agent excess, it helps to improve the curing rate of the coating and cross-linking density, which is conducive to improving the coating solvent resistance, pollution resistance, adhesion, drying speed, This can be adjusted according to the specific application.

According to the application of water-based epoxy resin coating requirements to select the appropriate pigments and fillers. China Epoxy Industry Association experts pointed out that the occasion of acid and alkali media can be used iron oxide and precipitation of barium sulfate and other pigments and fillers; for light and heat requirements of the occasion, you can use zinc oxide and mica iron oxide Fillers; to increase the chemical resistance of the coating and improve its mechanical properties, should choose mica and talc powder filler. Of course, taking into account the water-based epoxy curing agent was weakly alkaline, should avoid the use of acidic pigments and fillers, to avoid the two components after mixing demulsification and stratification. Water-based epoxy resin coating is a two-component coating, pigment filler can be added to the epoxy resin emulsion components can also be added to the water-based epoxy curing agent components, but for ease of use, should be added after the filler The equivalence of the two components is closer.

Additives are waterborne epoxy resin coating production, storage and construction of one of the indispensable components, should make full use of various additives on the coating and the final coating performance of the role of targeted selection of various additives. Water-based epoxy resin coating should be used as a film additives, defoamers, dispersants, rheology regulator, the specific choice should be considered with the water-based epoxy resin compatibility, to avoid the gel and Coating oil and other defects.