Expert: Epoxy paint baking skills

Expert: Epoxy paint baking skills

How can the steel drum industry save energy and ensure the baking quality of epoxy coatings? According to experts from China Epoxy Resin Industry Association (EP), epoxy coatings are one of the best coatings for metals, and the earliest and most common internal coatings used in the domestic steel drum industry. In the case of baking equipment at high temperature and baking, the barrel factory has a poor mastery of the process conditions, and it is difficult to ensure that the crosslinking reaction is complete, and it is difficult to ensure that the performance of the epoxy coating is fully reflected. The key to solving the problem is that the baking conditions can be effectively controlled.

One of the main film-forming materials for epoxy coatings is epoxy resin. China Epoxy Resin Industry Association () experts said that the active epoxy group in the epoxy resin structure can be cross-linked and cured with a variety of organic compounds to form a strong three-dimensional network structure film properties, epoxy coatings are used This property of epoxy resin is made up of a variety of coatings with different properties. Among all the materials which can be crosslinked and cured with epoxy resin, the epoxy resin and the butanol etherified phenolic resin are crosslinked and cured to form the film with the best performance and the strongest corrosion resistance. However, the crosslinking reaction of the epoxy resin with the butanol etherified phenolic resin must be started above 180 ° C, and if it is only this temperature, it must be maintained for more than 45 minutes.

Under such conditions, the cross-linking curing reaction can ensure that only 3 parts of water are released, no other by-products are released during the process, and the shrinkage is small. After cross-linking and solidification, the film has a good and firm dense network structure film. This further enhances the adhesion, mechanical properties, corrosion resistance and chemical resistance of the coating. However, such reaction conditions are unsatisfactory for the steel drum industry, so most barrel mills use a method of increasing the temperature and shortening the time. However, the equipment and baking conditions of the various barrel factories are different, and in this case It is difficult to test whether the epoxy resin and the phenolic resin are completely reacted under temperature and time conditions, so it is difficult to ensure that the crosslinking reaction is complete, and it is difficult to ensure that the performance of the epoxy coating is fully reflected.

How can we ensure the complete reaction of the epoxy resin with the phenolic resin and the effective control of the reaction conditions? China Epoxy Resin Industry Association () experts said that the use of additives can properly "get" the problem: adding 5% of the 1491 accelerator to the epoxy coating, can make epoxy resin and phenolic resin can be at 180 ° C for 15 minutes Complete reaction (if more than 210 ° C, the reaction can be completed in 2 minutes). In this way, not only the baking conditions of the epoxy coating can be effectively controlled, the performance of the epoxy coating is ensured, but also the baking temperature is lowered, the energy is saved, and the barrel factory without high-temperature baking conditions can also be produced. Epoxy coated steel drum.