Epoxy Resin TTA26 — A New-Generation Material for Cationic Flexible Packaging Inks

Flexible packaging is widely used in the food industry. With the growing emphasis on food safety, increasingly stringent requirements are being placed on inks used for food packaging. Although traditional UV acrylate free-radical curing inks offer fast curing speeds, they still have shortcomings in terms of migration, resistance to retort processing, adhesion, and flexibility. UV cationic systems, however, can effectively overcome these limitations of free-radical systems. The key lies in the use of a flexible cycloaliphatic epoxy resin—TTA26—as the main resin.

Tetra Epoxy Resin TTA26 is a typical cycloaliphatic difunctional epoxy resin. It is well known for its “excellent flexibility and cured film performance,” making it particularly suitable for cationic curing systems with high flexibility requirements. Its key application performance advantages are as follows:

01 Excellent flexibility

The introduction of an adipate ester bridge chain into the TTA26 molecular structure imparts outstanding flexibility and crack resistance to the ink film.

02 Low migration

The difunctionality of TTA26 provides good cationic curing activity, enabling rapid and complete curing in inks and resulting in low migration.

03 Good adhesion after curing

Epoxy resins exhibit low curing shrinkage, leading to strong adhesion between the ink film and flexible substrates.

Recommended applications

Food flexible packaging printing inks and overprint varnishes.

Reference formulation

Test results:

To meet the stringent requirements of food packaging, Tetra Epoxy Resin TTA26 was systematically evaluated from four aspects: food safety, mechanical properties, heat and water resistance, and chemical/media resistance. Test data confirm that its overall performance fully complies with the strict standards for food packaging inks. It not only effectively eliminates migration risks at the source, but also ensures excellent physical and chemical stability of the packaging during processing, transportation, and storage—providing brand owners with a reliable “technical assurance.”

Conclusion

With its unique alicyclic structure and cationic curing characteristics, TTA26 successfully addresses the long-standing challenge in flexible packaging inks of balancing toughness and retort resistance. It not only enhances the adhesion and stability of printed layers, but also offers new directions for green, high-performance ink formulations. In the future wave of environmentally friendly and high-performance packaging materials, TTA26 is more than just a resin—it is a key material driving the advancement of flexible printing technology.