Light Stabilizers
These substances are to protect plastics against
the damaging influence of light and to prevent consequential damage by the
influence of light (ageing) respectively. The consequential damages are
yellowing, embrittlement a.s.o. Polymers are protected against the light
damages as follows: 
- Special energy transfering substances ( such as nickel-derivates) also called quencher, deactivate excited state.
- Metal complexes of sulphur-containing compounds decompose formed hydrogen peroxide connections.
- Monomeric and polymeric HALS (hindered amine light stabilizers) intercept radicals.
- UV-Absorber with a high absorption capacity for ultraviolet radiation (such as substituted O-Hydroxybenzophenones, salicylic acid ester or hydroxyphenylene benztriazole etc.) prevent the light absorption of plastics at wavelengths < 420 nm, which correspond to the absorption maxima of the most polymers. The radiated energy is absorbed by the absorbers and converted into infra-red radiation (harmless heat).
Apart from their effectiveness light stabilizers have to be lightfast, must have a low inherent color, no tendency to discolor and a low volatility. The composition of our UV Masterbatches depends on the compatibility with the kind of plastic material which has to be protected, the spectral range and the intensity of the acting radiation, the heat stabilizers for the extrusion process and eventually the non-toxicity etc.
Infra-Red Absorbers
Special additives such as kaolin absorb infra-red radiation and are used as infra-red barriers in agricultural and horticultural applications. We test the effectiveness of active agents in our infra-red absorber masterbatches in our laboratories and in outdoor weathering.
Ageing
Due to irreversible chemical and physical processes the characteristic material properties such as toughness, transparency, color etc. deteriorate. The most frequent causes are heat, light, energetic radiation, chemicals, weather, ozone or combinations of these parameters.
Ageing Inhibitors
are stabilizers which slow down or inhibit the damaging influence of oxygene, ozone, light, temperature, humidity or heavy metals on plastics. Depending on their function these additives are classified in antioxidants, antiozoniants, light stabilizers which often are effective as radical interceptors.