Abstract: Nitroxyl inhibitors in combination with some oxygen reduce the premature polymerization of vinyl aromatic monomers during the manufacturing processes for such monomers. Even small quantities of air used in combination with the nitroxyl inhibitors result in vastly prolonged inhibition times for said monomers.

Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.

Abstract: The present invention relates to novel piperidine compounds of the formula (I) and to their use as light stabilizers, heat stabilizers and oxidation stabilizers for organic materials.The definitions of R.sub.1, R.sub.2 and R.sub.3 are given in the text.

Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a sulfoxide or sulfone group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.

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: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a sulfoxide or sulfone group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.

Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.

Abstract: The polymerization of a vinyl aromatic compound, such as styrene, during distillation or purification is very effectively inhibited by the presence of at least one stable nitroxyl compound together with at least one aromatic nitro compound.

Abstract: Liquid substituted 2H-benzotriazole mixtures are prepared by alkylation with concomitant dealkylation, fragmentation and realkylation of 2-(2-hydroxy-5-alkylphenyl)-2H-benzotriazoles or of 2-(2-hydroxy-3,5-dialkylphenyl)-2H-benzotriazoles with straight or branched alkenes of 8 to 30 carbon atoms in the presence of an acid catalyst at 100.degree.-200.degree. C. The liquid mixtures exhibit outstanding efficacy in protecting organic substrates from light induced deterioration as well as good resistance to loss by volatilization or exudation during the processing of stabilized compositions at elevated temperatures.

Abstract: Compounds which contain peroxide linkages as well as a hindered amine light stabilizer moiety of low basicity function as free radical polymerization initiators and provide a polymer containing a hindered amine stabilizer chemically bonded to said polymer. The low basicity of the instant compounds prevents interaction with acid catalysts used in some polymerization systems.

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 OR.sub.1 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: Compounds which contain peroxide linkages as well as a hindered amine light stabilizer moiety of low basicity function as free radical polymerization initiators and provide a polymer containing a hindered amine stabilizer chemically bonded to said polymer. The low basicity of the instant compounds prevents interaction with acid catalysts used in some polymerization 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: Liquid substituted, 2H-benzotriazole mixtures are prepared by alkylation with concomitant dealkylation, fragmentation and realkylation of 2-(2-hydroxy-5-alkylphenyl)-2H-benzotriazoles or of 2-(2-hydroxy-3,5-dialkylphenyl)-2H-benzotriazoles with straight or branched alkenes of 8 to 30 carbon atoms in the presence of an acid catalyst at 100.degree.-200.degree. C. The liquid mixtures exhibit outstanding efficacy in protecting organic substrates from light induced deterioration as well as good resistance to loss by volatilization or exudation during the processing of stabilized compositions at elevated temperatures.

Abstract: Compounds which contain peroxide linkages as well as a hindered amine light stabilizer moiety of low basicity function as free radical polymerization initiators and provide a polymer containing a hindered amine stabilizer chemically bonded to said polymer. The low basicity of the instant compounds prevents interaction with acid catalysts used in some polymerization systems.

Abstract: Liquid substituted 2H-benzotriazole mixtures are prepared by alkylation with concomitant dealkylation, fragmentation and realkylation of 2-(2-hydroxy-5-alkylphenyl)-2H-benzotriazoles or of 2-(2-hydroxy-3,5-dialkylphenyl)-2H-benzotriazoles with straight or branched alkenes of 8 to 30 carbon atoms in the presence of an acid catalyst at 100.degree.-200.degree. C. The liquid mixtures exhibit outstanding efficacy in protecting organic substrates from light induced deterioration as well as good resistance to loss by volatilization or exudation during the processing of stabilized compositions at elevated temperatures.

Abstract: 5-tert-Octyl-2-(2-hydroxy-3,5-di-alpha-cumylphenyl)-2H-benzotriazole and related 2H-benzotriazoles substituted on the 5-position of the benzo ring by a higher alkyl group such as tert-octyl or dodecyl exhibit outstanding efficacy in protecting organic substrates from light-induced deterioration as well as good resistance to loss by volatilization or exudation during the high temperature processing of stabilized compositions. The above-named compounds exhibit good solubility in common organic solvents, and exhibit very high extinction coefficients.

Abstract: 4-Aralkyl-2-nitro-2'-hydroxy-3',5'-dialkyl (or cumyl)-azobenzenes are made by coupling the corresponding diazotized 4-aralkyl-o-nitroaniline with the corresponding phenol. These azobenzene intermediates are used to prepare the corresponding 2H-benzotriazole UV absorber stabilizers substituted on the 5-position of the benzo ring by an aralkyl group, preferably alpha,alpha-dimethylbenzyl.

Abstract: 5-alpha-Cumyl-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole and related 2H-benzotriazoles substituted on the benzo ring by at least one aralkyl group such as benzyl, alpha-methylbenzyl or alpha-cumyl exhibit outstanding efficacy in protecting organic substrates from light-induced deterioration as well as good resistance to loss by volatilization or exudation during the high temperature processing of stabilized compositions. The above-named compounds are surprisingly soluble in common organic solvents, and exhibit very high extinction coefficients.

Abstract: 4-Higher alkyl-2-nitro-2'-hydroxy-3',5'-di-higher alkyl (or cumyl)-azobenzenes are made by coupling the corresponding diazotized 4-higher alkyl-o-nitroaniline with the corresponding substituted phenol. These azobenzene intermediates are used to prepare the corresponding 2H-benzotriazole UV absorber stabilizers substituted on the 5-position of the benzo ring by a higher alkyl group, preferably tert-octyl or n-dodecyl.