Abstract: The invention relates to a stabilizer composition comprising at least one processing stabilizer selected from special phosphite, mono- and diphosphonite compounds, at least one acid scavenger selected from the group consisting of selected metal stearates, hydrotalcites, oxides, hydroxides of alkaline earth metals, at least one UV stabilizer selected from compounds containing at least one 2,2,6,6-tetraalkylpiperidinyl-group and optionally at least one sterically hindered phenolic antioxidant. A further subject matter of the invention is a solid masterbatch composition or a liquid concentrate comprising above-mentioned stabilizer composition. The invention relates also to a process for stabilizing polymeric materials selected from the group consisting of special polyolefins comprising adding to the polymeric material a stabilizing quantity of said stabilizing composition.

Abstract: The invention relates to the use of piperidine compounds of the formula I in which R1 is hydroxyl, lower alkyl, lower alkoxy, R2 is a substituted or unsubstituted, mono- or bicyclic radical of aromatic type, R3 is oxygen, —NH— or —N(C1-4-alkyl)- and R8 independently at each occurrence is hydrogen or methyl for preparing light-stabilized, EPDM-modified polypropylene which is employed in particular in automotive construction, such as for shock absorbers, cover strips and the like. A further subject of the invention is the combination of abovementioned piperidine compounds with known UV absorbers. The invention also relates to EPDM-modified polypropylene which contains from 0.05 to 2.5% by weight, preferably from 0.1 to 0.6% by weight, of a radical of a compound of the above formula I, and to products produced therefrom.

Abstract: The invention relates to a process of using certain piperidine compounds of formula I ##STR1## in which R.sub.1 is hydrogen, hydroxyl, lower alkyl, lower alkoxy or acyl,R.sub.2 is a substituted or unsubstituted mono- or bicyclic radical which is aromatic in type,R.sub.3 is oxygen, --NH-- or --N(C.sub.1-4 -alkyl)-- andR.sub.8 independently at each occurrence is hydrogen or methylfor stabilizing natural or synthetic, organic or inorganic pigments or pigment mixtures in natural or synthetic, polymeric or prepolymeric substrates against the adverse effects of heat and/or light on the light fastness and color stability, respectively, especially against alterations in shade or light-induced bleaching. The invention also relates to a masterbatch composition.