The present invention relates to novel UV stabilizers of the formula (I) ##STR1## where the substituents are as defined in the description. These compounds are highly suitable for stabilizing organic material, such as plastics, surface coatings, paints and oils, against the action of light, radiation, oxygen and heat.
The invention relates to a synergistic mixture comprising a) at least one compound selected from the group consisting of the phosphites of the formula (I) to (V), of the phosphonites of the formulae (VI) to (IX) and (XV), of the di/oligophosphonites of the formulae (X) and (XI) and of the phosphinites of the formulae (XII) to (XIV), and b) at least one compound selected from the group consisting of the phosphanes of the formula (XVI), the di/oligophosphanes of the formulae (XVII) and (XVIII), and of the cyclophosphanes of the formula (XIX), and also to a process for stabilizing polymers with respect to thermooxidative degradation by addition and incorporation of a synergistic mixture of this type.
The present invention relates to a stabilizer composition comprising a) at least one sterically hindered phenol, b) at least one phosphorus-containing secondary antioxidant, and c) at least one Leucine compound, wherein the weight ratio of component (a) to component (b) to component (c) is from 1:5:3 to 1:0,5:0,1 for the stabilization of polyolefine-based thermoplastic polymers against degradation, crosslinking and/or discoloration due to the exposure to heat and/or light, especially in the presence of oxygen.