Epoxy resins, derived from the condensation reaction between epichlorohydrin and biphenol A (diphenol propane), form the basis of a wide variety of protective and decorative materials. There are several types of epoxy resin combinations, the four most important being: epoxy-phenolic, epoxy-amines, epoxy-esters and modified epoxies. The most widely used are the epoxy-phenolic ones, which are universal in use.

Epoxy-phenolic coatings are widely used because the phenolic resin provides chemical resistance properties and the epoxy provides mechanical and adhesion properties. These coatings have excellent adhesion and flexibility, making them suitable for deep-drawn containers, and their color is generally golden. They have good resistance to most foods and, although their resistance to sulfuration is good, it is inferior to that of phenolic varnishes. However, they are better against the action of polyphosphates and other additives used in meat canning. For sulfurizing products, additives such as aluminum or zinc oxide powder are added, the former masks sulfuration and the latter absorbs the sulfur ion formed by the degradation of proteins by heat, forming zinc sulfide which is white and does not alter the final appearance of the package.

Modified epoxy resins are used in interior systems and are one of the possibilities for white coatings as an alternative to white organosols and polyesters. They can also be used as coupling varnishes or simply as exterior colorless varnishes.

On the other hand, high molecular weight epoxy resins have been used as modification resins for welding protection powder. It has been possible to produce high molecular weight epoxy resins with no residual BADGE content, which has made it possible to formulate BADGE-free enamels and solder protection powders. These products are widely used and are considered standard products, although they still contain epoxy resins.

In terms of sustainability and regulation, we are working with a range of sanitary varnishes based on epoxy resins, polyester resins, acrylics and BPANI varnishes, which allow us to package all types of food products, adapting to the characteristics of each product and to the food legislation of the destination country.

Coatings for metal containers Varnishes on Food Cans: Technology, Applications and Trends Tin sulfuration in food cans What is BADGE? what is an epoxyphenol varnish? Epoxy Varnish on Food and Beverage Cans: Features, Applications and Benefits Differences between BPANI and Epoxy coatings: a technical comparison Properties of a varnish for metal containers What are the main differences between BPAni, BPA-free and expoxy coatings?