When it comes to curing speed and stability, photoinitiator 180 is an excellent choice! Photoinitiator 180 has excellent reactivity and can cure quickly under mercury lamp conditions. It can also be used under LED light sources after adding photosensitizers. It is colorless and transparent, odorless after reaction, and non-migrating.
Effect of curing temperature on reaction rate and coating properties
Maintaining a certain curing temperature has a very positive effect on the curing reaction speed. It is recommended to use cationic UV curing products in an environment not lower than 25℃. As the use temperature continues to rise, even if the application environment increases by 5℃, the curing reaction efficiency will be significantly improved. If a heating device is set in front of the UV light source to keep the curing temperature constant between 40-60℃, even a very short heating time can ensure efficient curing and stable quality, and save expensive initiator addition. Therefore, because cationic curing solvent coatings usually have a heating process before curing, the recommended addition of initiator is only 1-3%.
Effect of Heating on Cationic Post-Curing
The cationic curing reaction does not quench when the light source is interrupted, but the resin continues to crosslink with different acid-generating strengths. The degree of crosslinking will be significantly improved within 1-5 minutes after illumination, and it will reach a relatively ideal state within 1-2 hours, and the highest degree of curing reaction can be reached in 2-7 days. If heating conditions are provided after illumination, the crosslinking speed and the final curing strength can be promoted. Therefore, by utilizing the characteristics of cationic post-curing and controlling the curing crosslinking speed, it can be bonded to some opaque materials and applied, and multiple layers can be re-coated without worrying about the problem of interlayer adhesion.
The initiator 180 is triarylsulfonium hexafluoroantimonate. Because the sulfur atom can be conjugated with three aromatic rings, the positive charge is dispersed, and it can be cracked after light excitation to produce polymerization active species, which has stronger reactivity than phosphate. The addition amount is only 40-60% of triarylsulfonium hexafluorophosphate. It has higher cross-linking hardness, no migration, no odor, temperature resistance, and good deep curing. The absorption wavelength is 290nm, which has both high performance and economy. It is used in cationic curing transparent coatings, adhesives, LED packaging, inks and other fields.