Composition testing and formulation analysis of UV curing coatings

UV-curable coatings are composed of UV-curable resin (main resin), photoinitiator (photosensitizer), pigment filler and auxiliary agent.

UV curing resin in UV curing coating formula: there are many kinds of UV curing resin. UV curing resins are generally unsaturated polyester, vinyl ether resin, unsaturated polyester acrylates, polyurethane acrylates and epoxy resins.

UV curable coating formulation photoinitiator: in the UV curable powder coating system, the melting point of photoinitiator should be lower than the working temperature of solid compound. When the base material is melted, the photoinitiator is not volatile, yellow, stable at the melting temperature, does not produce chemical reactions triggered by heat. Free radical photoinitiator and cationic photoinitiator can be used in UV curing powder coatings.

Curing agent for the formulation of UV-curable coatings: curing agent plays a decisive role in the aggregation state of polymers, and plays a crucial role in the storage period and film forming conditions of powder coatings. The type of curing agent is determined by the active group with which the matrix resin is used, which is generally hydroxyl group, carboxyl group, epoxy group and C C unsaturated double bond.

UV curing coating formula color filler: many pigments (such as carbon black, iron oxide yellow, etc.) will absorb or scatter UV radiation, to a certain extent to prevent UV curing. Rutile titanium dioxide and anatase titanium dioxide are commonly used.

UV-curable coating formula auxiliaries: UV-curable powder coating, leveling agent can be added to solve coating surface defects caused by leveling; Adding UV absorbers and steric blocking amine light stabilizers (HALS), UV absorbers (e.g., hydroxyphenyl-S-triazines) filter out harmful UV radiation from sunlight that causes initial photodegradation of the polymer, and also help preserve the deeper color and adhesion of the coating.