Abstract: Hindered amines based on various 2,2,6,6-tetraalkylated nitrogen-containing heterocyclic moieties wherein the hindered nitrogen atom on the ring is substituted with O-acyl, O-carbamoyl or O-carbonate substituents and the 4-position of the ring is substituted with a variety of groups, are effective as light stabilizers in diverse substrate systems.

Abstract: N-OR.sub.1 substituted hindered amine light stabilizers impart outstanding stabilization properties to acid catalyzed thermoset coating compositions providing enhanced resistance against the deleterious effects of light, moisture or oxygen without inhibition of cure.

Abstract: N-hydroxy substituted hindered amine light stabilizers impart outstanding stabilization properties to acid catalyzed thermoset coating compositions with enhanced resistance against the deleterious effects of light, moisture or oxygen in the substantial absence of cure inhibition.

Abstract: Compounds of the formula (T).sub.g -E where T is a substituted 4-acyl-2-piperazinone group, g is 1 or 2 and E is a selected terminal or linking group, are effective light stabilizers for polyolefins and other organic polymers, particularly thermoset acrylic or alkyd acrylic resins.

Abstract: Nitroxyls of the formula ##STR1## where E.sub.1, E.sub.2, E.sub.3 and E.sub.4 are independently an organic radical so that the carbon atoms to which they are attached are each a quaternary carbon and T is a divalent radical are prepared by the oxidation of the corresponding amine in an inert organic solvent with a hydroperoxide in the presence of a metal carbonyl, metal oxide or metal alkoxide catalyst in high yield and purity. The nitroxyls may be directly reduced to the corresponding hydroxylamines by catalytic hydrogenation. The nitroxyls are useful as polymerization inhibitors and the hydroxylamines as polymer stabilizers.

Abstract: Compounds of the formula (T).sub.g -E where T is a substituted 4-acyl-2-piperazinone group, g is 1 or 2 and E is a selected terminal or linking group, are effective light stabilizers for polyolefins and other organic polymers.

Abstract: Polyhydroxylamines are effective in stabilizing polyolefin compositions containing a stabilizer or mixture of stabilizers selected from the group consisting of the phenolic antioxidants, the hindered amine light stabilizers, the alkylated hydroxybenzoate light stabilizers, the ultraviolet light absorbers, the organic phosphorus compounds, the alkaline metal salts of fatty acids and the thiosynergists, against degradation upon high temperature extrusion, exposure to the combustion products of natural gas, gamma irradiation or upon storage for extended periods.

Abstract: Compounds of the formula L-T, where L is an unsubstituted or substituted tetrahydro-1,4-oxazine-2-one group and T is a substituted 4-piperidinyl hindered amine moiety, are effective light stabilizers for polyolefins and other organic polymers.

Abstract: Compounds of the formula (L--T).sub.g --E (I) or (L--T--G) .sub.h --Q (II), where L is a lactam group, T is a substituted 4-piperidinyl hindered amine moiety and E or Q are selected linking or terminal groups, are effective light stabilizers for polyolefins and other organic polymers.

Abstract: Oligomeric esteramides having recurring structural units of the formula ##STR1## where G is a hindered amine radical of formula I or II ##STR2## in which R.sup.1 is hydrogen or alkyl having 1 to 4 carbon atoms, R.sup.2 is hydrogen, alkyl having 1 to 12 carbon atoms, allyl, benzyl, acetyl, acryloyl or cyano, Z.sub.1 is a direct bond, --NHCH.sub.2 CH.sub.2 --, --NHCH.sub.2 CH.sub.2 CH.sub.2 -- or --OCH.sub.2 CH.sub.2 --, Z.sub.2 is ethylene or trimethylene, E is a divalent aliphatic, aromatic or alicyclic radical and L is unsubstituted or substituted alkylene, are useful light stabilizers for plastics.

Abstract: Lubricants stabilized against oxidative degradation by the incorporation therein of 2,3-dihydroperimidine derivatives as well as certain 2,3-dihydroperimidines within the indicated group.