Specialty chemicals Antioxidants / UV absorbers / UV stabilizers / UV photoinitiators

UV absorber

serves as a coating and is partially absorbed into the stratum corneum of the skin. The effect of the UV absorber is based on the Stokes shift for absorbed UV radiation; for organic UV absorbers the Stokes shift occurs due to conjugated double bonds.

UV stabilizers

are chemical compounds that are added as additives to various materials, such as polymers, to protect against aging caused by UV radiation.

Plastics

When used, plastics are subject to photooxidation due to photolysis. This creates various radicals that attack the material. The radicals break the main chains of the polymer and incorporate various polar compounds such as peroxides. The consequences of this degradation are loss of color, cracking and generally negative effects on physical properties.

Varnishes

UV absorbers and radical scavengers are used in paints to improve weather stability. It is particularly important in clear coats that the UV stabilizers used are colorless and do not change color. Due to the tendency to migrate, the base paint in two-layer systems is also equipped with UV stabilizers, although it is already protected from ultraviolet radiation by a stabilized top coat.

Photoinitiators are components of radiation-curing paint and resin formulations that can be cured in fractions of a second by irradiation with UV light. They are used, for example, in diazotype, stereolithography and multi jet modeling.