Abstract: The present invention relates to the use of a photoreactive and UV absorbing piperidine compound of the formula A below and of a mixture consisting of this piperidine compound and at least one selected UV absorber as light stabilizers in coating materials, preferably in automotive coating materials. The invention also provides a method of stabilizing coating materials against the degradation of the polymer material present in the coating material, as induced by the action of atmospheric oxygen, heat and/or UV light, and the coating materials themselves that are stabilized in this way.

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 subject matter of the invention is the use of certain piperidine compounds of formula I ##STR1## optionally in combination with an oxalanide UV absorber for the stabilization of pigmented or unpigmented polyolefins against the negative consequences of UV radiation. The invention also relates to compositions comprising a piperidine compound of formula I, a polyolefin, and an oxalanide UV absorber and compositions comprising a compound of formula I and a second HALS compound.

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.

Abstract: A composition, suitable for stabilizing a polymeric composition against the effects of light, comprisinga) an N-acylated 2,2,6,6-tetraalkylpiperidinyl group (hereinafter N-acylated HALS) containing compound; andb) an N-oxy-subst. 2,2,6,6-tetraalkylpiperidinyl group (hereinafter N-oxy-substituted HALS) containing compound.A further aspect of the invention relates to a composition, suitable for stabilizing a polymeric composition against the effects of light, comprisinga) an N-acylated 2,2,6,6-tetraalkylpiperidinyl-group-containing compound in which a spiro group is attached in the 4-position (hereinafter defined as component i); andb) an N-acylated 2,2,6,6-tetraalkylpiperidinyl-group-containing compound in which in the 4-position no spiro group is present (hereinafter defined as component ii).These compounds are suitable as light stabilizers in acid catalyzed lacquer system.

Abstract: A compound of formula I for use in stabilizing polymeric material against effects such as light and heat ##STR1## in which R is hydrogen; oxygen; --OH; C.sub.1-24 alkyl; --O--CO--C.sub.1-24 alkyl; --O--CO--C.sub.1-24 alkyl; --O--CO-phenyl or --COR.sub.5 ; where R.sub.5 is --C(R.sub.3).dbd.CH.sub.2, C.sub.1-6 alkyl, phenyl, CO--C.sub.1-24 alkyl, --CO--phenyl, --NR.sub.7 R.sub.8, --CH.sub.2 --C.sub.6 H.sub.5, --CO--OC.sub.1-12 alkyl or --COOH; where R.sub.3 is hydrogen or C.sub.1-4 alkyl; R.sub.7 is hydrogen, C.sub.1-12 alkyl, C.sub.5-6 cycloalkyl, phenyl, phenyl-C.sub.1-4 alkyl or C.sub.1-12 alkylphenyl and R.sub.8 is C.sub.1-12 alkyl or hydrogen,each R.sub.1, independently, is --CH.sub.3 or --CH.sub.2 (C.sub.1-4 alkyl) or both groups R.sub.1 form a group --(CH.sub.2).sub.5 --; andeach R.sub.2, independently, is --CH.sub.3 or --CH.sub.2 (C.sub.1-4 alkyl) or both groups R.sub.2 form a group --(CH.sub.2).sub.5 --.A is --O-- or --N(C.sub.1-4 alkyl)-- or --NH--R.sub.9 is hydrogen or methyl, andR.sub.