CHISORB® 327 is an ultraviolet light absorber for plastics, coatings and adhesives. It is one of a family of substituted benzotriazoles which protect against ultraviolet radiation. CHISORB® 327 has a low pKa and a hindered phenolic group. As a result, the molecule is more stable to acid and alkali, and less affected by the reducing and oxidizing agents commonly used in polymerization and curing. Also, it is much less sensitive to metal containing ingredients which used to cause discoloration, impaired performance and other problems. This product is a pale yellow crystalline powder or granule. CHISORB® 327 should prove valuable as a light protective agent for polyolefins and cold-cured polyester resin.