A brief history of plastic additives. Part 2: UV/light stabilizers

The development of suitable UV/light stabilizers has been a decisive element for the success of plastics and for the extension of applications to long-term outdoor use. UV absorbers and later on hindered amine light stabilizers (HALS) have provided efficient protection of plastics from the deleterious influence of UV light. UV absorbers on the basis of benzophenones, benzotriazoles or hydroxyphenyl triazines and other structures are in use for many application fields. Low molecular weight und oligomeric HALS combine light and thermal stability and various structures including alkoxy amines have been developed. Many successful products fulfill today´s market needs and are available on a global basis from different producers. Other promising products survived only for a short time. Recent developmental aspects are focused on synergistic application-tailored combinations. In the area of HALS novel structures and improvements of synthetic processes are still an industrial topic. The present review covers historic developments with focus on the last 30 years and intends to fill an information gap triggering potential novel ideas for light stabilizers.