Antioxidants / UV Absorbers / UV Stabilizers

The UV absorber
serves as a coating and is partially absorbed into the horny layer of the skin. The effect of the UV absorber is based on the Stokes shift in the case of absorbed UV radiation; in the case of organic UV absorbers, the Stokes shift occurs due to conjugated double bonds.

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

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

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