Tetramethylpiperidine compounds for use as stabilisers for organic materials

Abstract: The present invention relates to novel tetramethylpiperidine compounds of the formula (I) in which R₁ is e.g. hydrogen or methyl, R₂ and R₃ are e.g. -(CH₂)₂-, R₄ is e.g. -CO-, -COCO- or -COCH₂CO-, n is e.g. 1 and R₅ is e.g. hydrogen or allyl. These compounds are suitable for use as light stabilisers, heat stabilisers and oxidation stabilisers for organic materials.

Description: The present invention relates to novel piperidine compounds, to their use as light stabilisers, heat stabilisers and oxidation stabilisers for organic materials, in particular synthetic polymers, and to the materials thus stabilised. The stabilisation of synthetic polymers with derivatives of 2,2,6,6-tetramethylpiperidine has been described in numerous patents, in particular in US Patents 3 684 765, 3 904 581, 3 925 376, 4 108 829, 4 279 804, 4 316 025, 4 433 145, 4 533 688 and 4 740 544 and in European Laid Open Prints 117 229, 176 106, 227 640, 410 934 and 491 659. The present invention relates to novel compounds of the formula (I) in which R₁ is hydrogen, C₁-C₈alkyl, O, OH, CH₂CN, C₁-C₁₈alkoxy, C₅-C₁₂cycloalkoxy, C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or C₁-C₈acyl, R₂ and R₃ which can be identical or different are C₂-C₃alkylene, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4, and, when n is 1, R₅ is hydrogen, C₁-C₁₈alkyl, C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or R₅ is one of the groups of the formulae (IIa)-(IIc) -COR₆ -(CO) p COOR₇ in which X₁ and X₂ which can be identical or different are a group -OR₈, -SR₈ or where R₈, R₉ and R₁₀ which can be identical or different are hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy; C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; C₂-C₄alkyl substituted in the 2-,3- or 4-position by OH, by C₁-C₈alkoxy or by di(C₁-C₄alkyl)amino; a group of the formula in which X is a direct bond, -O-, -CH₂- or -CH₂CH₂- ; tetrahydrofurfuryl or a group of the formula (III) where R₁₁ is as defined for R₁, or is 1-pyrrolidyl, 1-piperidyl, 4-morpholinyl, 4-methyl-1-piperazinyl or 1-hexahydroazepinyl, or X₁ and X₂ are one of the groups of the formulae (IVa)-(IVd) with R₁₁ as defined above, R₆ is hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₂-C₁₈alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy and/or by an OH group; C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl and/or an OH group; p is zero or 1, and R₇ is C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), and, when n is 2, R₅ is C₂-C₁₂alkylene, C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms; 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) -CO-R₁₂-CO- -COO-R₁₃-OOC- -(CH₂) q CO- in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI) where R₁, R₂, R₃ and R₄ are as defined above, E₁ is one of the groups of the formulae (VIIa)-(VIIc) -G₁-R₁₄-G₂- in which G₁, G₂ and G₃ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), R₁₄ is C₂-C₁₂alkylene, C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 groups where R₁₉ is as defined above for R₁₈ or is C₁-C₈acyl or (C₁-C₈alkoxy)carbonyl; or R₁₄ is further C₅-C₇cycloalkylene unsubstituted or substituted by C₁-C₄alkyl; C₅-C₇cycloalkylenedi(C₁-C₄alkylene), C₁-C₄alkylenedi(C₅-C₇cycloalkylene), C₂-C₄alkylidenedi(C₅-C₇cycloalkylene), phenylene unsubstituted or substituted by C₁-C₄alkyl; phenylenedi(C₁-C₄alkylene), C₁-C₄alkylenediphenylene or C₂-C₄alkylidenediphenylene, R₁₅ is C₂-C₆alkylene, G₄ is one of the groups >N-(R₁₅-G₃) s , >CH-O- or with R₁₈ as defined above, r and s which can be identical or different are zero or 1, R₁₆ is hydrogen or can also be methyl when r is 1 and G₄ is >CH-O-, and R₁₇ is hydrogen or methyl, R₁₂ is a direct bond, C₁-C₁₂alkylene, C₂-C₄alkenylene, cyclohexylene, cyclohexenylene or phenylene, R₁₃ is C₂-C₁₂alkylene, C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms, C₅-C₇cycloalkylene unsubstituted or substituted by C₁-C₄alkyl, C₅-C₇cycloalkylenedi(C₁-C₄alkylene) or C₂-C₄alkylidenedi(C₅-C₇cycloalkylene) and q is zero or an integer from 1 to 10, and when n is 3, R₅ is aliphatic C₄-C₁₈triacyl, aromatic C₉-C₁₈triacyl or a group of the formula (VIII) in which X₃ is as defined above and E₂ is one of the groups of the formula (IXa)-(IXc) in which G₅, G₆ and G₇ which can be identical or different are as defined above for G₁, G₂ and G₃; R₂₀, R₂₁ and R₂₂ which can be identical or different are C₂-C₆alkylene, t is zero or 1, R₂₃, R₂₄ and R₂₅ which can be identical or different are as defined above for R₁₈; G₈ is a direct bond or -CH₂-, u and v which can be identical or different are integers from 2 to 6 and R₂₆ is C₃-C₁₂alkanetriyl, and, when n is 4, R₅ is aliphatic C₆-C₁₈tetraacyl, aromatic C₁₀-C₁₈tetraacyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) in which X₃ is as defined above and E₃ is one of the groups of the formulae (XIa)-(XIc) R₂₉-(-O-)₄- in which G₉ is as defined above for G₁, G₂ and G₃; R₂₇ and R₂₈ which can be identical or different are C₂-C₆alkylene, w is zero or 1 and R₂₉ is C₄-C₁₂alkanetetrayl. Examples of alkyl having not more than 18 carbon atoms are methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl and octadecyl. Examples of OH-substituted C₂-C₄alkyl are 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-hydroxybutyl and 4-hydroxybutyl, 2-Hydroxyethyl is preferred. Examples of C₂-C₄alkyl substituted by C₁-C₈alkoxy, preferably C₁-C₄alkoxy, in particular methoxy or ethoxy, are 2-methoxyethyl, 2-ethoxyethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-butoxypropyl, 3-octoxypropyl and 4-methoxybutyl. Examples of C₂-C₄alkyl substituted by di(C₁-C₄alkyl)amino, preferably by dimethylamino or diethylamino, are 2-dimethylaminoethyl, 2-diethylaminoethyl, 3-dimethylaminopropyl, 3-diethylaminopropyl, 3-dibutylaminopropyl and 4-diethylaminobutyl. A preferred meaning for the group of the formula is the group Examples of alkoxy having not more than 18 carbon atoms are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy and octadecyloxy. C₆-C₁₂Alkoxy, in particular heptoxy or octoxy, is preferred for R₁ and R₁₁. Examples of substituted or unsubstituted C₅-C₁₂cycloalkyl are cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, trimethylcyclohexyl, t-butylcyclohexyl, cyclooctyl, cyclodecyl and cyclododecyl. Cyclohexyl which is unsubstituted or substituted by C₁-C₄alkyl is preferred. Representative examples of C₅-C₁₂cycloalkoxy R₁ and R₁₁ are cyclopentoxy, cyclohexoxy, cycloheptoxy, cyclooctoxy, cyclodecyloxy and cyclododecyloxy. Cyclopentoxy and cyclohexoxy are preferred. Examples of alkenyl having not more than 18 carbon atoms are vinyl, allyl, 2-methylallyl, butenyl, hexenyl, decenyl, undecenyl, heptadecenyl and oleyl. When R₁ and R₁₁ are C₃-C₆alkenyl, the carbon atom in the 1 position is preferably saturated. Examples of substituted phenyl are methylphenyl, dimethylphenyl, trimethylphenyl, t-butylphenyl, di-t-butylphenyl, 3,5-di-t-butyl-4-methylphenyl, methoxyphenyl, ethoxyphenyl, hydroxyphenyl and 3,5-di-t-butyl-4-hydroxyphenyl. Examples of C₇-C₉phenylalkyl which is unsubstituted or substituted on the phenyl are benzyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl, t-butylbenzyl, 2-phenylethyl and 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl. Acyl R₁, R₁₁ and R₁₉ having not more than 8 carbon atoms can be an aliphatic or aromatic group. Representative examples are formyl, acetyl, propionyl, butyryl, pentanoyl, hexanoyl, heptanoyl, octanoyl, benzoyl, acryloyl or crotonyl. C₁-C₈alkanoyl, C₃-C₈alkenoyl and benzoyl are preferred. Acetyl is especially preferred. When is 1-pyrrolidyl, 1-piperidyl, 4-morpholinyl, 4-methyl-1-piperazinyl or 1-hexahydroazepinyl, the group 4-morpholinyl is preferred. Examples of alkylene having not more than 12 carbon atoms are methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, 2,2-dimethyltrimethylene, hexamethylene, trimethylhexamethylene, decamethylene and dodecamethylene. Examples of C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms are 3-oxapentane-1,5-diyl, 3,6-dioxaoctane-1,8-diyl, 4,7-dioxadecane-1,10-diyl, 4,9-dioxadodecane-1,12-diyl, 3,6,9-trioxaundecane-1,11-diyl and 4,7,10-trioxatridecane-1,13-diyl. Preferred examples of C₄-C₁₂alkylene R₁₄ interrupted by 1 or 2 groups are the groups Representative examples of groups containing 1 or 2 C₅-C₇cycloalkylene groups are cyclohexylene, methylcyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene and isopropylidenedicyclohexylene. Representative examples of groups containing 1 or 2 phenylene groups are phenylene, methylphenylene, dimethylphenylene, phenylenedimethylene, methylenediphenylene and isopropylidenediphenylene. Examples of C₂-C₄alkenylene are vinylene, methylvinylene and dimethylvinylene. Aliphatic C₄-C₁₈triacyl R₅ can be unsubstituted or substituted by a OH group. Preferred examples are the thiacyl derivatives of methanetricarboxylic, 1,1,2-ethanetricarboxylic, 1,2,3-propanetricarboxylic, citric or 1,2,3-butanetricarboxylic acid. Aromatic C₉-C₁₈triacyl R₅ is, for example, a triacyl derivative of 1,2,4-benzenetricarboxylic or 1,3,5-benzenetricarboxylic acid. Preferred examples of C₃-C₁₂alkanetriyl R₂₆ are 1,2,3-propanetriyl, 1,2,4-butanetriyl, 1,2,6-hexanetriyl or a group Aliphatic C₆-C₁₈tetraacyl R₅ is, for example, a tetraacyl derivative of 1,1,3,3-propanetetracarboxylic acid or 1,2,3,4-butanetetracarboxylic acid. Aromatic C₁₀-C₁₈tetraacyl R₅ is, for example, a tetraacyl derivative of 1,2,4,5-benzenetetracarboxylic acid. Preferred examples of C₄-C₁₂alkanetetrayl R₂₉ are 1,2,3,4-butanetetrayl and the group (C₁-C₈alkoxy)carbonyl is for example methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, hexoxycarbonyl, heptoxycarbonyl or octoxycarbonyl. The preferred definitions of R₁ and R₁₁ are hydrogen, C₁-C₄alkyl, OH, C₆-C₁₂alkoxy, C₅-C₈cycloalkoxy, allyl, benzyl or acetyl, in particular hydrogen or methyl. Those compounds of the formula (I) are preferred in which R₂ and R₃ which can be identical or different are C₂-C₃alkylene, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, C₁-C₁₈alkyl, C₃-C₄alkenyl, benzyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or R₅ is one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈, -SR₈ or where R₈, R₉ and R₁₀ which can be identical or different are hydrogen, C₁-C₁₈alkyl, C₅-C₈cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy; benzyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; C₂-C₃alkyl substituted in the 2- or 3- position by OH, by C₁-C₄alkoxy, by di(C₁-C₄alkyl)amino or by a group where X is a direct bond, -O-, -CH₂- or -CH₂CH₂-; tetrahydrofurfuryl or a group of the formula (III), or the group is a group as defined above, or X₁ and X₂ are one of the groups of the formulae (IVa)-(IVd), R₆ is hydrogen, C₁-C₁₇alkyl, C₅-C₈cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₂-C₁₇alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy and/or a OH group; benzyl or phenylethyl which both are unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl and/or an OH group; p is zero or 1, R₇ is C₁-C₁₈alkyl, C₅-C₈cycloalkyl which is mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, benzyl which is unsubstituted or mono-, di- or trisubstituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), and, when n is 2, R₅ is C₂-C₁₀alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms; 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups of the formulae (VIIa)-(VIIc) in which G₁, G₂ and G₃ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₁₈alkyl, C₅-C₈cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; benzyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), R₁₄ is C₂-C₁₀alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 groups where R₁₉ is as defined above for R₁₈ or is C₁-C₆acyl or (C₁-C₆alkoxy)carbonyl; or R₁₄ is further cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene, phenylene, phenylenedimethylene, methylenediphenylene or isopropylidenediphenylene, R₁₅ is C₂-C₄alkylene, G₄ is >N-(R₁₅-G₃) s -, >CH-O- or with R₁₈ as defined above, r and s which can be identical or different are zero or 1, R₁₆ is hydrogen or can also be methyl when r is 1 and G₄ is >CH-O-, and R₁₇ is hydrogen or methyl, R₁₂ is a direct bond, C₁-C₁₀alkylene, vinylene, cyclohexylene or phenylene, R₁₃ is C₂-C₁₀alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms; cyclohexylene, cyclohexylenedimethylene or isopropylidenedicyclohexylene, and q is zero or an integer from 1 to 5, and, when n is 3, R₅ is aliphatic C₄-C₁₂triacyl, aromatic C₉-C₁₂triacyl or a group of the formula (VIII) in which X₃ is as defined above and E₂ is one of the groups of the formulae (IXa)-(IXc) in which G₅, G₆ and G₇ which can be identical or different are as defined above for G₁, G₂ and G₃; R₂₀, R₂₁ and R₂₂ which can be identical or different are C₂-C₆alkylene, t is zero or 1, R₂₃, R₂₄ and R₂₅ which can be identical or different are as defined above for R₁₈; G₈ is a direct bond or -CH₂-, u and v which can be identical or different are integers from 2 to 6 and R₂₆ is C₃-C₁₀alkanetriyl, and, when n is 4, R₅ is aliphatic C₆-C₁₂tetraacyl, aromatic C₁₀-C₁₂tetraacyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) in which X₃ is as defined above and E₃ is a group of the formulae (XIa)-(XIc) in which G₉ is as defined above for G₁, G₂ and G₃; R₂₇ and R₂₈ which can be identical or different are C₂-C₆alkylene, w is zero or 1 and R₂₉ is C₄-C₈alkanetetrayl. Those compounds of the formula (I) are particularly preferred in which R₂ and R₃ which can be identical or different are C₂-C₃alkylene, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, methyl, C₄-C₁₈alkyl, allyl, benzyl or one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈, -SR₈ or where R₈, R₉ and R₁₀ which can be identical or different are hydrogen, C₁-C₁₂alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; allyl, undecenyl, phenyl, benzyl, C₂-C₃alkyl substituted in the 2- or 3-position by OH, by C₁-C₄alkoxy, by dimethylamino, by diethylamino or by 4-morpholinyl; tetrahydrofurfuryl or a group of the formula (III), or the group is 4-morpholinyl, or X₁ and X₂ are one of the groups of the formulae (IVa)-(IVd), R₆ is C₂-C₁₇alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₂-C₁₀alkenyl, phenyl, t-butylphenyl, 3,5-di-t-butyl-4-hydroxyphenyl, benzyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero or 1 and R₇ is C₂-C₁₈alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; allyl, undecenyl, oleyl, benzyl or a group of the formula (III), and, when n is 2, R₅ is C₂-C₈alkylene, C₄-C₈alkylene interrupted by 1 or 2 oxygen atoms; 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups of the formulae (VIIa)-(VIIc) in which G₁, G₂ and G₃ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₁₂alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; benzyl or a group of the formula (III), R₁₄ is C₂-C₈alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 groups where R₁₉ is as defined above for R₁₈ or is C₁-C₄acyl or (C₁-C₄alkoxy)carbonyl; or R₁₄ is further cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene, phenylenedimethylene or isopropylidenediphenylene, R₁₅ is C₂-C₃alkylene, G₄ is >N-(R₁₅-G₃) s - or >CH-O-, r and s which can be identical or different are zero or 1, R₁₆ is hydrogen or can also be methyl when r is 1 and G₄ is >CH-O-, and R₁₇ is hydrogen or methyl, R₁₂ is a direct bond, C₁-C₈alkylene or phenylene, R₁₃ is C₂-C₈alkylene, C₄-C₈alkylene interrupted by 1 or 2 oxygen atoms; cyclohexylenedimethylene or isopropylidenedicyclohexylene and q is zero or an integer from 1 to 3, and, when n is 3, R₅ is aliphatic C₄-C₈triacyl, benzenetricarbonyl or a group of the formula (VIII) in which X₃ is as defined above and E₂ is one of the groups of the formulae (IXa)-(IXc) in which G₅, G₆ and G₇ which can be identical or different are as defined above for G₁, G₂ and G₃; R₂₀, R₂₁ and R₂₂ which can be identical or different are C₂-C₄alkylene, t is zero or 1, R₂₃, R₂₄ and R₂₅ which can be identical or different are as defined above for R₁₈; G₈ is a direct bond or -CH₂-, u and v which can be identical or different are integers from 3 to 6 and R₂₆ is C₃-C₆alkanetriyl, and, when n is 4, R₅ is aliphatic C₆-C₈tetraacyl, benzenetetracarbonyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) in which X₃ is as defined above and E₃ is a group of the formulae (XIa)-(XIc) in which G₉ is as defined above for G₁, G₂ and G₃; R₂₇ and R₂₈ which can be identical or different are C₂-C₄alkylene, w is zero or 1 and R₂₉ is C₄-C₆alkanetetrayl. Those compounds of the formula (I) are of special interest in which R₂ and R₃ which can be identical or different are -(CH₂)₂- or -(CH₂)₃-, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, methyl, C₈-C₁₈alkyl, allyl or one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈ or where R₈ is C₁-C₈alkyl or a group of the formula (III), R₉ and R₁₀ which can be identical or different are C₁-C₈alkyl, cyclohexyl, C₂-C₃alkyl substituted in the 2- or 3-position by methoxy, by ethoxy, by dimethylamino, by diethylamino or by 4-morpholinyl; or are tetrahydrofurfuryl or a group of the formula (III), or R₉ can also be hydrogen or the group is 4-morpholinyl, R₆ is C₃-C₁₇alkyl, cyclohexyl, phenyl, 3,5-di-t-butyl-4-hydroxyphenyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero, R₇ is C₄-C₁₈alkyl, cyclohexyl, t-butylcyclohexyl or a group of the formula (III), and, when n is 2, R₅ is one of the groups of the formulae (Va)-(Ve) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups of the formulae (VIIa)-(VIIc) in which G₁ and G₂ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₈alkyl, cyclohexyl or a group of the formula (III), R₁₄ is C₂-C₆alkylene, C₆-C₁₀alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene or methylenedicyclohexylene, the group (VIIb) is one of the groups where r and s which can be identical or different are zero or 1, R₁₈ is as defined above and R₁₇ is hydrogen or methyl, R₁₂ is C₂-C₈alkylene or phenylene, R₁₃ is C₄-C₈alkylene or isopropylidenedicyclohexylene and q is zero or 1, and when n is 3, R₅ is a group of the formula (VIII) in which X₃ is as defined above and E₂ is a group of the formula (IXa) or (IXb) in which G₅ and G₆ which can be identical or different are as defined above for G₁ and G₂; R₂₀ and R₂₁ which can be identical or different are C₂-C₃alkylene, t is zero, R₂₃, R₂₄ and R₂₅ are as defined above for R₁₈; G₈ is a direct bond or -CH₂- and u and v which can be identical or different are integers from 3 to 5, and, when n is 4, R₅ is a group of the formula (X) in which X₃ is as defined above and E₃ is a group of the formula (XIa) in which G₉ is as defined above for G₁ and G₂; R₂₇ and R₂₈ which can be identical or different are C₂-C₃alkylene and w is zero or 1. Those compounds of the formula (I) are of particular interest in which R₁ is hydrogen or methyl, R₂ and R₃ are -(CH₂)₂-, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, methyl, allyl or one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈ or where R₈ is C₁-C₄alkyl, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl, R₉ and R₁₀ which can be identical or different are C₁-C₄alkyl, cyclohexyl, tetrahydrofurfuryl, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl or R₉ can also be hydrogen, or the group is 4-morpholinyl, R₆ is C₄-C₁₇alkyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero and R₇ is C₄-C₁₈alkyl, and, when n is 2, R₅ is one of the groups of the formulae (Va)-(Vd) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups where R₁₈ is hydrogen, methyl, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl, R₁₂ is C₄-C₈alkylene or phenylene and R₁₃ is C₄-C₆alkylene, and, when n is 3, R₅ is a group of the formula (VIII) in which X₃ is as defined above and E₂ is a group where R₁₈ is as defined above, and, when n is 4, R₅ is a group of the formula (X) in which X₃ is as defined above and E₃ is a group with R₁₈ as defined above. Those compounds of the formula (I) are also of interest in which R₁ is hydrogen or methyl, R₂ and R₃ are -(CH₂)₂-, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2 or 3 and, when n is 1, R₅ is hydrogen, allyl or one of the groups of the formulae (IIb) or (IIc) in which R₆ is C₄-C₁₇alkyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero and R₇ is C₄-C₁₈alkyl, and, when n is 2, R₅ is one of the groups of the formulae (Vb) or (Vc) in which X₃ is a group of the formula (VI), E₁ is one of the groups where R₁₈ is hydrogen, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl, R₁₂ is phenylene and, when n is 3, R₅ is a group of the formula (VIII) in which X₃ is as defined above and E₂ is a group where R₁₈ is as defined above. The compounds of the formula (I) can be prepared by processes known per se, for example by reacting a compound of the formula (XII) with suitable alkylating or acylating agents in the appropriate molar ratios. In this way, the compounds of the formula (I) with R₁ = H are obtained, from which the corresponding compounds with R₁ ≠ H can subsequently be obtained. The reactions are conveniently carried out in an inert solvent, operating at temperatures from e.g. -20° to 200°C, preferably from -10° to 180°C. The compounds of the formula (XII) can be prepared e.g. according to scheme 1 by reacting a compound of the formula (XIII) with a compound of the formula (XIV) in which A is -NH₂- or C₁-C₄alkoxy. The reactions according to scheme 1 can be carried out in the presence or absence of an inert organic solvent at temperatures from e.g. 100° to 280°C, preferably from 150° to 250°C. The compounds of the formula (XIII) can be prepared according to known processes for example by reductive alkylation of a triamine H₂N-R₂-NH-R₃-NH₂ with 2,2,6,6-tetramethyl-4-piperidone in the presence of a hydrogenation catalyst. The compounds of the formula (XIV) are commercially available. As mentioned at the outset, the compounds of the formula (I) are highly effective in improving the light stability, heat stability and oxidation stability of organic materials, in particular synthetic polymers and copolymers. Examples of such organic materials which can be stabilised are: 1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, polybutene-1, polymethylpentene-1, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene (which optionally can be crosslinked), for example high-density polyethylene (HDPE), low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). 2. Mixtures of the polymers mentioned under 1), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of different types of polyethylene (for example LDPE/HDPE). 3. Copolymers of monoolefins and diolefins with each other or with other vinyl monomers, such as, for example, ethylene/propylene, linear low-density polyethylene (LLDPE) and its mixtures with low-density polyethylene (LDPE), propylene/butene-1, ethylene/hexene, ethylene/ethylpentene, ethylene/heptene, ethylene/octene, propylene/isobutylene, ethylene/butene-1, propylene/butadiene, isobutylene/isoprene, ethylene/alkyl acrylates, ethylene/alkyl methacrylates, ethylene/vinyl acetate or ethylene/acrylic acid copolymers and their salts (ionomers) and terpolymers of ethylene with propylene and a diene, such as hexadiene, dicyclopentadiene or ethylidenenorbornene; as well as mixtures of such copolymers and their mixtures with polymers mentioned in 1) above, for example polypropylene/ethylene-propylene copolymers, LDPE/EVA, LDPE/EAA, LLDPE/EVA and LLDPE/EAA. 3a. Copolymers of α-olefins with carbon monoxide, with regular or random alternation. 3b. Hydrocarbon resins (for example C₅-C₉) and hydrogenated modifications thereof (for example tackifiers). 4. Polystyrene, poly-(p-methylstyrene), poly-(α-methylstyrene). 5. Copolymers of styrene or α-methylstyrene with dienes or acrylic derivatives, such as, for example, styrene/acrylonitrile, styrene/alkyl methacrylate, styrene/maleic anhydride, styrene/butadiene/ethyl acrylate, styrene/acrylonitrile/methyl acrylate; mixtures of high impact strength from copolymers of styrene and other polymers, such as, for example, from a polyacrylate, a diene polymer or an ethylene/propylene/diene terpolymer and block copolymers of styrene, such as, for example, styrene/butadiene/styrene, styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/styrene. 6. Graft copolymers of styrene or α-methylstyrene such as, for example, styrene on polybutadiene; styrene on polybutadiene-styrene or polybutadiene-acrylonitrile; styrene and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene and maleic anhydride or maleimide on polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide on polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene; styrene and alkyl acrylates or methacrylates on polybutadiene; styrene and acrylonitrile on ethylene/propylene/diene terpolymers; styrene and acrylonitrile on polyacrylates or polymethacrylates; styrene and acrylonitrile on acrylate/butadiene copolymers, as well as mixtures thereof with the copolymers listed under 5), for instance the mixtures known as ABS, MBS, ASA and AES polymers. 7. Halogen-containing polymers, such as polychloroprene, chlorinated rubbers, chlorinated or sulfochlorinated polyethylene, epichlorohydrin homo- and copolymers, polymers from halogen-containing vinyl compounds, such as for example polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, as well as copolymers thereof, for example vinyl chloride/vinylidene chloride, vinyl chloride/vinyl acetate or vinylidene chloride/vinyl acetate copolymers. 8. Polymers which are derived from α,β-unsaturated acids and derivatives thereof, such as polyacrylates and polymethacrylates, polyacrylamide and polyacrylonitrile. 9. Copolymers from the monomers mentioned under 8) with each other or with other unsaturated monomers, such as, for instance, acrylonitrile/butadiene, acrylonitrile/alkyl acrylate, acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide copolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers. 10. Polymers which are derived from unsaturated alcohols and amines, or acyl derivatives thereof or acetals thereof, such as polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, polyallyl phthalate or polyallylmelamine; as well as their copolymers with olefins mentioned in 1) above. 11. Homopolymers and copolymers of cyclic ethers, such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or copolymers thereof with bis-glycidyl ethers. 12. Polyacetals, such as polyoxymethylene and those polyoxymethylenes which contain ethylene oxide as a comonomer; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS. 13. Polyphenylene oxides and sulfides, and mixtures of polyphenylene oxides with polystyrene or polyamides. 14. Polyurethanes which are derived from polyethers, polyesters or polybutadienes with terminal hydroxyl groups on the one side and aliphatic or aromatic polyisocyanates on the other side, as well as precursors thereof (polyisocyanates, polyols or prepolymers). 15. Polyamides ad copolyamides which are derived from diamines and dicarboxylic acids and/or from aminocarboxylic acids or the corre- sponding lactams, such as polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12 polyamide 11, polyamide 12, aromatic polyamides obtained by condensation of m-xylene diamine and adipic acid; polyamides prepared from hexamethylenediamine and isophthalic or/and terephthalic acid and optionally an elastomer as modifier, for example poly-2,4,4,-trimethylhexamethylene terephthalamide or poly-m-phenylene isophthalamide. Further copolymers of the aforementioned polyamides with polyolefins, olefin copolymers, ionomers or chemically bonded or grafted elastomers; or with polyethers, such as for instance, with polyethylene glycols, polypropylene glycols or polytetramethylene glycols. Polyamides or copolyamides modified with EPDM or ABS. Polyamides condensed during processing (RIM-polyamide systems). 16. Polyureas, polyimides and polyamide-imides. 17. Polyesters which are derived from dicarboxylic acids and diols and|[ch]or from hydroxycarboxylic acids or the corresponding lactones, such as polyethylene terephthalate, polybutylene terephthalate, poly-1,4-dimethylolcyclohexane terephthalate, poly-[2,2,-(4-hydroxyphenyl)- propane] terephthalate and polyhydroxybenzoates as well as block-copolyether-esters derived from polyethers having hydroxyl end groups. 18. Polycarbonates and polyester-carbonates. 19. Polysulfones, polyether-sulfones and polyether-ketones. 20. Crosslinked polymers which are derived from aldehydes on the one hand and phenols, ureas and melamines on the other hand, such as phenol/formaldehyde resins, urea/formaldehyde resins and melamine/formaldehyde resins. 21. Drying and non-drying alkyd resins. 22. Unsaturated polyester resins which are derived from copolyesters of saturated and unsaturated dicarboxylic acids with polyhydric alcohols and vinyl compounds as crosslinking agents, and also halogen-containing modifications thereof of low inflammability. 23. Thermosetting acrylic resins, derived from substituted acrylic esters, such as epoxy-acrylates, urethane-acrylates or polyester-acrylates. 24. Alkyd resins, polyester resins or acrylate resins in admixture with melamine resins, urea resins, polyisocyanates or epoxide resins as crosslinking agents. 25. Crosslinked epoxide resins which are derived from polyepoxides, for example from bis-glycidyl ethers or from cycloaliphatic diepoxides. 26. Natural polymers, such as cellulose, rubber, gelatine and derivatives thereof which are chemically modified in a polymer-homologous manner, such as cellulose acetates, cellulose propionates and cellulose butyrates, or the cellulose ethers, such as methylcellulose; rosins and their derivatives. 27. Mixtures of polymers as mentioned above, for example PP/EPDM, Polyamide 6/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPE/HIPS, PPE/PA 6.6 and copolymers, PA/HDPE, PA/PP, PA/PPE. 28. Naturally occurring and synthetic organic materials which are pure monomeric compounds or mixtures of such compounds, for example mineral oils, animal and vegetable fats, oil and waxes, or oils, fats and waxes based on synthetic esters (e.g. phthalates, adipates, phosphates or trimellithates) and also mixtures of synthetic esters with mineral oils in any weight ratios, which materials may be used as plasticizer for polymers or as textile spinning oils, as well as aqueous emulsions of such materials. 29. Aqueous emulsions of natural or synthetic rubber, e.g. natural latex or latices of carboxylated styrene/butadiene copolymers. The compounds of the formula (I) are particularly suitable for improving the light stability, heat stability and oxidation stability of polyolefins, especially polyethylene and polypropylene. The compounds of the formula (I) can be used in mixtures with organic materials in various proportions depending on the nature of the material to be stabilised, on the end use and on the presence of other additives. In general, it is appropriate to use, for example, 0.01 to 5 % by weight of the compounds of the formula (I), relative to the weight of the material to be stabilised, preferably between 0.05 and 1 %. In general, the compounds of the formula (I) can be incorporated in the polymeric materials before, during or after the polymerization or crosslinking of the said materials. The compounds of the formula (I) can be incorporated in the polymeric materials in the pure form or encapsulated in waxes, oils or polymers. The compounds of the formula (I) can be incorporated in the polymeric materials by various processes, such as dry mixing in the form of powder, or wet mixing in the form of solutions or suspensions or also in the form of a masterbatch; in such operations, the polymer can be used in the form of powder, granules, solutions, suspensions or in the form of latices. The materials stabilised with the products of the formula (I) can be used for the production of mouldings, films, tapes, monofilaments, fibres, surface coatings and the like. If desired, other conventional additives for synthetic polymers, such as antioxidants, UV absorbers, nickel stabilisers, pigments, fillers, plasticisers, antistatic agents, flameproofing agents, lubricants, corrosion inhibitors and metal deactivators, can be added to the mixtures of the compounds of the formula (I) with the organic materials. The conventional additives are e.g. present in an amount of 0.01 to 10 % by weight, relative to the weight of the organic material to be stabilized. Particular examples of additives which can be used in admixture with the compounds of the formula (I) are: 1. Antioxidants 1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methyl-phenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-iso-butylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexyl-phenol, 2,6-di-tert-butyl-4-methoxymethylphenol, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1'-methyl-undec-1'-yl)-phenol, 2,4-dimethyl-6-(1'methyl-heptadec-1'-yl)-phenol, 2,4-dimethyl-6-(1'-methyl-tridec-1'-yl)-phenol and mixtures therof. 1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4-nonylphenol. 1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxy-phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-di-phenyl-4-octadecyloxyphenol, 2,6-di-tert-butyl-hydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxy-phenyl-stearate, bis-(3,5-di-tert-butyl-4-hydroxyphenyl)adipate. 1.4. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thio-bis(6-tert-butyl-2-methylphenol), 4,4'-thio-bis-(3,6-di-sec-amylphenol), 4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl)-disulfide. 1.5. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(α-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis-(3'-tert-butyl-4'-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene, bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate, 1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butan, 2,2-bis-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propan, 2,2-bis-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercapto-butan, 1,1,5,5-tetra-(5-tert.-butyl-4-hydroxy-2-methylphenyl)-pentan. 1.6. O-, N- and S-benzyl compounds , for example 3,5,3',5'-tetra-tert.-butyl-4,4'-dihydroxy-dibenzylether, octadecyl-4-hydroxy-3,5-dimethylbenzyl-mercaptoacetate, tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-amine, bis-(4-tert.-butyl-3-hydroxy-2,6-dimethylbenzyl)-dithioterephthalate, bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-sulfide, isooctyl-3,5-di-tert.-butyl-4-hydroxybenzyl-mercaptoacetate. 1.7. Hydroxybenzylated Malonates , for example dioctadecyl-2,2-bis-(3,5-di-tert.-butyl-2-hydroxybenzyl)-malonate, di-octadecyl-2-(3-tert.-butyl-4-hydroxy-5-methylbenzyl)-malonate, di-dodecylmercaptoethyl-2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate, Di-[4-(1,1,3,3-tetramethylbutyl)-phenyl]-2,2-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-malonate. 1.8. Hydroxybenzyl-Aromatics , for example 1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis-(3,5-di-tert.-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene, 2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-phenol. 1.9. Triazine Compounds , for example 2,4-bis-octylmercapto-6-(3,5-di-tert.-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-1,3,5-triazine, 2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris-(3,5-di-tert.-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-tris-(4-tert.-butyl-3-hydroxy-2,6-dimethylbenzyl)-isocyanurate, 2,4,6-tris-(3,5-di-tert.-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris-(3,5-di-tert.butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine, 1,3,5-tris-(3,5-dicyclohexyl-4-hydroxybenzyl)-isocyanurate. 1.10. Benzylphosphonates , for example dimethyl-2,5-di-tert.-butyl-4-hydroxybenzylphosphonate, diethyl-3,5-di-tert.-butyl-4-hydroxybenzylphosphonate, dioctadecyl-3,5-di-tert.-butyl-4-hydroxybenzylphosphonate, dioctadecyl-5-tert.-butyl-4-hydroxy-3-methylbenzylphosphonate, Ca-salt of the 3,5-di-tert.-butyl-4-hydroxybenzyl-phosphonic acid monoethylester. 1.11. Acylaminophenols , for example lauric acid 4-hydroxyanilide, stearic acid 4-hydroxyanilide, octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamate. 1.12. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-thoxabicyclo-[2.2.2]-octane. 1.13. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-[2.2.2]-octane. 1.14 Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-[2.2.2]-octane. 1.15 Esters of 3,5-di-tert.-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxalic acid diamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-[2.2.2]-octane. 1.16. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g. N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylene-diamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)tri-methylene-diamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine. 2. UV absorbers and light stabilisers 2.1. 2-(2'-Hydroxyphenyl)benzotriazoles, for example the 5'-methyl, 3',5'-di-tert-butyl, 5'-tert-butyl, 5'-(1,1,3,3-tetramethylbutyl), 5-chloro-3',5'-di-tert-butyl, 5-chloro-3'-tert-butyl-5'-methyl, 3'-sec-butyl-5'-tert-butyl, 4'-octoxy, 3',5'-di-tert-amyl and 3',5'-bis(α,α- dimethylbenzyl), mixture of 5-chloro-3'-tert.-butyl-5'-(2-octyloxycarbonylethyl)- and 5-chloro-3'-tert.-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-, 5-chloro-3'-tert.-butyl-5'-(2-methoxycarbonylethyl)-, 3'-tert.-butyl-5'-(2-methoxycarbonylethyl)-, 3'-tert.-butyl-5'-(2-octyloxycarbonylethyl)-, 3'-tert.-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-, 3'-dodecyl-5'-methyl- and 3'-tert.-butyl-5'-(2-isooctyloxycarbonylethyl)-2'-hydroxyphenyl-2H-benztriazole(2), 2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benztriazole-2-yl-phenol]; product of ester interchange of 2-[3'-tert.-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxy-phenyl]-2H-benztriazole with polyethylene glycol 300; [R-CH₂CH₂-COO(CH₂)₃]₂ with R=3'-tert.-butyl-4'-hydroxy-5'-2H-benzotriazole-2-yl-phenyl. 2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivatives. 2.3. Esters of substituted and unsubstituted benzoic acids , as for example 4-tert.butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis-(4-tert.butylbenzoyl)-resorcinol, benzoylresorcinol, 2,4-di-tert.butylphenyl 3,5-di-tert.butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert.butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert.-butyl-4-hydroxybenzoate, 2 methyl-4,6-di-tert.-butylphenyl 3,5-di-tert.-butyl-4-hydroxybenzoate. 2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctyl α-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methyl α-cyano-β-methyl-p-methoxy-cinnamate, butyl α-cyano-β-methyl-p-methoxy-cinnamate, methyl α-carbomethoxy-p-methoxycinnamate and N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline. 2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, nickel salts of 4-hydroxy-3,5-di-tert-butylbenzyl-phosphonic acid monoalkyl esters, e.g. of the methyl or ethyl ester, nickel complexes of ketoximes, e.g. of 2-hydroxy-4-methyl-phenyl undecyl ketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands. 2.6. Sterically hindered amines, for example bis(2,2,6,6-tetramethyl-piperidyl) sebacate, bis-(2,2,6,6-tetramethyl-piperidyl) succinate, bis(1,2,2,6,6-pentamethylpiperidyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxy-benzylmalonate, the condensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the condensation product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4- piperidyl)-1,2,3,4-butane-tetracarboxylate, 1,1'-(1,2-ethanediyl)bis-(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis-(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert.-butyl-benzyl) malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazasprio[4.5]decan-2,4-dion, bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate, bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate, product of condensation of N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylene diamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, product of condensation of-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-thazine and 1,2-bis-(3-aminopropylamino)ethane, product of condensation of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazapiro[4.5]decane-2,4-dion, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dion, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidin-2,5-dion. 2.7. Oxalic acid diamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-dioctyloxy-5,5'-di-tert-butyloxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butyloxanilide, 2-ethoxy-2'-ethyloxanilide, N,N'-bis(3-dimethylamino-propyl)oxalamide, 2-ethoxy-5-tert-butyl-2'-ethyloxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert-butyloxanilide and mixtures of ortho- and para-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides. 2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxy-phenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5- triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine. 3. Metal deactivators, for example N,N'-diphenyloxalic acid diamide, N-salicylal-N'-salicyloylhydrazine, N,N'-bis(salicyloyl)hydrazine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine , 3-salicyl-oylamino-1,2,4-triazole, bis(benzylidene)oxalodihydrazide, Oxanilide, isophthalic acid dihydrazide, sebacic acid-bis-phenylhydrazide, N,N'-diacetal-adipinic acid dihydrazide, N,N'-bis-salicyloyl-oxalic acid dihydrazide, N,N'-bis-salicyloyl-thiopropionic acid dihydrazide. 4. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diiso- decyl pentaerythritol diphosphite, bis(2,4-di-tert.-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert.-butyl-4-methylphenyl)-pentaeryt hritol diphosphite, bis-isodecyloxy-pentaerythritol diphosphite, bis-(2,4-di-tert.-butyl-6-methylphenyl)-pentaerythritol diphosphite, bis-(2,4,6-tri-tert.-butylphenyl)-pentaerythritol diphsophite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4'-bi-phenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert.-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra-tert.-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin. 4a. Hydroxylamines , for example dibenzylhydroxylamine, dioctylhydroxylamine, didodecylhydroxylamine, ditetradecylhydroxylamine, dihexadecylhydroxylamine, dioctadecylhydroxylamine, 1-hydroxy-2,2,6,6-tetramethyl-4-piperidyl benzoate or bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate. 5. Peroxide scavengers, for example esters of β-thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zinc dibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritol tetrakis(β-dodecyl-mercapto)propionate. 6. Polyamide stabilisers, for example, copper salts in combination with iodides and/or phosphorus compounds and salts of divalent manganese. 7. Basic co-stabilisers, for example, melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids for example Ca stearate, Zn stearate, Mg behenate, Mg stearate, Na ricinoleate and K palmitate, antimony pyrocatecholate or zinc pyrocatecholate. 8. Nucleating agents, for example, 4-tert.butyl-benzoic acid, adipic acid, diphenylacetic acid. 9. Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass fibres, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxydes, carbon black, graphite. 10. Other additives, for example, plasticisers, lubricants, emulsifiers, pigments, optical brighteners, flameproofing agents, antistatic agents and blowing agents. The compounds of the formula (I) can also be used as stabilisers, especially as light stabilisers, for almost all materials known in the art of photographic reproduction and other reproduction techniques as e.g. described in Research Disclosure 1990, 31429 (pages 474 to 480). Several examples of the preparation and use of the compounds of the formula (I) are reported for more detailed illustration of the present invention; these examples are given solely for illustrative purposes and do not imply any restriction. The compounds disclosed in the following Examples 1, 2, 13, 14, 16, 20 and 22 relate to a particularly preferred embodiment of the present invention. Example 1: Preparation of the compound of the formula 152.7 g (0.4 mol) of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)diethylenetriamine and 26.4 g (0.44 mol) of urea are heated for 2 hours at 150°C and for 2 hours at 230°C under a gentle stream of nitrogen. The product obtained is crystallised from octane. Melting point 93-94°C. Analysis for C₂₃H₄₅N₅O Calculated: C = 67.77 %; H = 11.13 %; N = 17.18 % Found: C = 67.48 %; H = 11.05 %; N = 17.20 % Example 2: Preparation of the compound of the formula 152.7 g (0.4 mol) of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)diethylenetriamine, 47.2 g (0.4 mol) of dimethyl oxalate and 550 ml of trimethylbenzene are heated under reflux for 1 hour, with removal of the methanol formed in the reaction. The reaction mixture is cooled to 5°C; the precipitate formed is separated off by filtration, washed with acetone and dried. Melting point 237-238°C. Analysis for C₂₄H₄₅N₅O₂ Calculated: C = 66.17 %; H = 10.41 %; N = 16.08 % Found: C = 66.01 %; H = 10.38 %; N = 16.02 % Example 3: Preparation of the compound of the formula 152.7 g (0.4 mol) of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)diethylenetriamine and 58.1 g (0.44 mol) of dimethyl malonate are heated for 1 hour at 160-190°C, with removal of the methanol formed in the reaction. The product obtained is crystallised from methyl ethyl ketone. Melting point 205-206°C. Analysis for C₂₅H₄₇N₅O₂ Calculated: C = 66.78 %; H = 10.53 %; N = 15.57 % Found: C = 66.78 %; H = 10.52 %; N = 15.51 % Example 4: Preparation of the compound of the formula 8.6 g (0.063 mol) of butyl chlorocarbonate are slowly added at a temperature not exceeding 0°C to a solution, cooled to -10°C, of 24.5 g (0.06 mol) of the compound from Example 1 in 100 ml of 1,2-dichloroethane. A solution of 2.6 g (0.065 mol) of sodium hydroxide in 25 ml of water is then added slowly, maintaining the temperature at 0°C. Alter the end of the addition, the reaction mixture is stirred for 1 hour at ambient temperature. The aqueous layer is separated off and the organic phase a washed with water, dried over anhydrous Na₂SO₄ and evaporated in vacuo up to 70°C. The product obtained is crystallised from hexane. Melting point 108-109°C. Analysis for C₂₈H₅₃N₅O₃ Calculated: C = 66.23 %; H = 10.52 %; N = 13.79 % Found: C = 66.30 %; H = 10.51 %; N = 13.78 % Example 5: The compound of the formula is prepared as described in Example 4, by reacting 7.2 g (0.053 mol) of butyl chlorocarbonate and 21.8 g (0.05 mol) of the compound from Example 2, in 150 ml of 1,2-dichloroethane. The product obtained is crystallised from ethyl acetate. Melting point 178-179°C. Analysis for C₂₉H₅₃N₅O₄ Calculated: C = 65.01 %; H = 9.97 %; N = 13.07 % Found: C = 64.95 %; H = 9.90 %; N = 12.98 % Example 6: The compound of the formula is prepared as described in Example 4 by reacting 7.2 g (0.053 mol) of butyl chlorocarbonate and 22.5 g (0.05 mol) of the compound from Example 3 in 150 ml of 1,2-dichloroethane. The product is crystallised from hexane. Melting point 152-153°C. Analysis for C₃₀H₅₅N₅O₄ Calculated: C = 65.54 %; H = 10.08 %; N = 12.74 % Found: C = 65.46 %; H = 10.07 %; N = 12.70 % Example 7: The compound of the formula is prepared as described in Example 4 by reacting 6.6 g (0.055 mol) of pivaloyl chloride and 22.5 g (0.05 mol) of the compound from Example 3 in 250 ml of 1,2-dichloroethane. The product obtained is crystallised from hexane. Melting point 193-194°C. Analysis for C₃₀H₅₅N₅O₃ Calculated: C = 67.50 %; H = 10.38 %; N = 13.12 % Found: C = 67.41 %; H = 10.32 %; N = 13.07 % Example 8: The compound of the formula is prepared as described in Example 4 by reacting 10.2 g (0.063 mol) of octanoyl chloride and 24.5 g (0.06 mol) of the compound from Example 1 in 200 ml of 1,2-dichloroethane. The product is crystallised from octane. Melting point 97-98°C. Analysis for C₃₁H₅₉N₅O₂ Calculated: C = 69.75 %; H = 11.14 %; N = 13.12 % Found: C = 69.78 %; H = 11.12 %; N = 13.11 % Example 9: Preparation of the compound of the formula A solution of 14.8 g (0.05 mol) of 3-(3,5-di-t-butyl-4-hydroxyphenyl)propanoyl chloride in 50 ml of toluene is added slowly at ambient temperature to a solution of 20.4 g (0.05 mol) of the compound from Example 1 and 5.1 g (0.05 mol) of triethylamine in 100 ml of toluene. The mixture is stirred for one hour at ambient temperature and then heated for 2 hours at 60°C. After cooling to ambient temperature, a solution of 2 g (0.05 mol) of sodium hydroxide in 25 ml of water is added and the mixture is stirred for 30 minutes. The aqueous layer is separated off and the organic phase is washed with water, dried over anhydrous Na₂SO₄ and evaporated in vacuo up to 80°C. The residue is crystallised from petroleum ether of boiling point 50-70°C. Melting point 168-169°C. Analysis for C₄₀H₆₉N₅O₃ Calculated: C = 71.92 %; H = 10.41 %; N = 10.48 % Found: C = 72.01 %; H = 10.39 %; N = 10.43 % Example 10: Preparation of the compound of the formula A solution of 5.1 g (0.025 mol) of terephthaloyl chloride in 80 ml of chloroform is added slowly to a solution of 20.4 g (0.05 mol) of the compound from Example 1 in 100 ml of chloroform, maintaining the temperature between 0° and 10°C. The mixture is stirred for 12 hours at ambient temperature, and a solution of 2.1 g (0.0525 mol) of sodium hydroxide in 50 ml of water is then added slowly. Alter stirring for 1 hour at ambient temperature, the organic phase is separated off, washed with water, dried over anhydrous Na₂SO₄ and evaporated in vacuo up to 80°C. The residue obtained is crystallised from acetone. Melting point 225-226°C. Analysis for C₅₄H₉₂N₁₀O₄ Calculated: C = 68.61 %; H = 9.81 %; N = 14.82% Found: C = 68.29 %; H = 9.76 %; N = 14.72 % Example 11: Preparation of the compound of the formula 26.6 g (0.22 mol) of allyl bromide are added in 2 hours to a mixture, heated at 70°C, containing 81.5 g (0.2 mol) of the compound of Example 1, 400 ml of toluene, 8.8 g of sodium hydroxide and 40 ml of water. At the end of the addition, the mixture is heated for 5 hours at 80°C and then, the aqueous layer is separated off. The solvent is evaporated in vacuo and the residue is crystallized from hexane. The product so obtained has a melting point of 63-65°C. Analysis for C₂₆H₄₉N₅O Calculated: C = 69.75 %; H = 11.03 %; N = 15.64 % Found: C = 69.40 %; H = 10.90 %; N = 15.57 % Example 12: The compound of the formula is prepared as described in Example 11, using the compound of Example 2. The product obtained has a melting point of 162-164°C. Analysis for C₂₇H₄₉N₅O₂ Calculated: C = 68.17 %; H = 10.38 %; N = 14.72 % Found: C = 67.69 %; H = 10.35 %; N = 14.67 % Example 13: Preparation of the compound of the formula 81.5 g (0.2 mol) of the compound from Example 1 are added slowly to a solution, cooled to 10°C, of 18.5 g (0.1 mol) of cyanuric chloride in 220 ml of xylene, maintaining the temperature between 10° and 20°C. Alter the end of the addition, the mixture is stirred for 1 hour at ambient temperature, 8 g (0.2 mol) of sodium hydroxide dissolved in 30 ml of water are added, the mixture is heated for 2 hours at 70°C, and the aqueous layer is then separated off. 5.8 g (0.05 mol) of 1,6-hexanediamine and 8 g (0.2 mol) of ground sodium hydroxide are added, and the mixture is heated under reflux for 16 hours, the water of reaction being separated off azeotropically. 200 ml of xylene are added, and the mixture is filtered hot. Alter cooling to ambient temperature, the precipitate formed is separated off by filtration and dried in vacuo. Melting point 151-153°C. Analysis for C₁₀₄H₁₉₀N₂₈O₄ Calculated: C = 65.85 %; H = 10.10 %; N = 20.68 % Found: C = 66.05 %; H = 10.02 %; N = 20.57 % Examples 14-17: Following the procedure described in Example 13 and using the respective reagents in the appropriate molar ratios, the following compounds of the formula are prepared. Example 18: Preparation of the compound of the formula 87.12 g (0.2 mol) of the compound of Example 2 are slowly added to a solution, cooled at 10°C, of 18.5 g (0.1 mol) of cyanuric chloride in 220 ml of xylene, maintaining the temperature between 10° and 20°C. After the end of the addition, the mixture is stirred for 1 hour at ambient temperature. 8 g (0.12 mol) of sodium hydroxide dissolved in 30 ml of water are added, the mixture is heated for 2 hours at 70°C and then, the aqueous layer is separated off. The solvent is evaporated in vacuo and the residue is dissolved in 800 ml of 2-methoxyethylether. Subsequently, 5.8 g (0.05 mol) of 1,6-hexanediamine and 5.5 g of potassium carbonate are added and the mixture is heated at reflux for 8 hours. After cooling to ambient temperature, the precipitate formed is separated off by filtration, dissolved in 400 ml of dichloromethane and washed with water. Then, the organic solvent is evaporated and the residue is dried in vacuo. The product obtained has a melting point of 257-259°C. Analysis for C₁₀₈H₁₉₀N₂₈O₈ Calculated: C = 64.57 %; H = 9.53 %; N = 19.52 % Found: C = 64.50 %; H = 9.51 %; N = 19.36 % Examples 19-20: Following the procedure described in Example 18 and using the respective reagents in the appropriate molar ratios, the following compounds of the formula are prepared. Example 21: Preparation of the compound of the formula A solution containing 3 g (0.1 mol) of formaldehyde and 4.6 g (0.1 mol) of formic acid in 10 ml of water is added in 3 hours to a solution, heated to 110°C, of 19 g (0.01 mol) of the compound from Example 13 in 100 ml of xylene, with simultaneous removal of the water added and of the water of reaction. The mixture is then cooled to 70°C, a solution of 6 g of sodium hydroxide in 50 ml of water is added, and the mixture is stirred for 30 minutes. Alter separating off the aqueous phase, the organic layer is washed with water, dried over anhydrous Na₂SO₄ and evaporated under reduced pressure. The product obtained is washed with hexane and dried. Melting point 241-243°C. Analysis for C₁₁₂H₂₀₆N₂₈O₄ Calculated: C = 66.96 %; H = 10.33 %; N = 19.52 % Found: C = 66.57 %; H = 10.29 %; N = 19.41 % Example 22: The compound of the formula is prepared as described in Example 21, using the compound from Example 16. The product obtained is crystallised from hexane. Melting point 181-183°C. Analysis for C₁₆₅H₃₀₂N₄₂O₆ Calculated: C = 66.72 %; H = 10.25 %; N = 19.80 % Found: C = 67.01 %; H = 10.21 %; N = 19.81 % Example 23: The compound of the formula is prepared as described in Example 21, using the compound of Example 14, The melting point of the product obtained is 221-223°C. Analysis for C₁₃₂H₂₄₄N₃₀O₄ Calculated: C = 68.47 %; H = 10.62 %; N = 18.15 % Found: C = 67.90 %; H = 10.59 %; N = 18.06 % Example 24: The compound of the formula is prepared as described in Example 21, using the compound of Example 18. The melting point of the product obtained is 285-287°C. Analysis for C₁₁₆H₂₀₆N₂₈O₈ Calculated: C = 65.69 %; H = 9.79 %; N = 18.49 % Found: C = 65.03 %; H = 9.73 %; N = 18.39 % Example 25: (light-stabilising action in polypropylene fibres) 2.5 g of each of the products indicated in Table 1, 1 g of tris(2,4-di-t-butylphenyl) phosphite, 0.5 g of calcium monoethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate, 1 g of calcium stearate and 2.5 g of titanium dioxide are mixed in a slow mixer with 1000 g of polypropylene powder of melt index = 12 g/10 minutes (measured at 230°C and 2.16 kg). The mixtures are extruded at 200-230°C to give polymer granules which are then converted into fibres, using a pilot-type apparatus (®Leonard-Sumirago (VA) Italy) operating under the following conditions: Extruder temperature: 200-230°C Head temperature: 255-260°C Stretch ratio: 1:3.5 Count: 11 dtex per filament The fibres thus prepared are exposed, mounted on a white card, in a model 65WR Weather-O-Meter (ASTM D 2565-85) with a black panel temperature of 63°C. The residual tenacity is measured on samples taken after various times of exposure to light by means of a constant-speed tensometer, and the exposure time in hours (T₅₀) needed to halve the initial tenacity is then calculated. Fibres prepared under the same conditions as indicated above, but without addition of stabilisers of the invention, are exposed for comparison. The results obtained are shown in Table 1. Stabiliser T₅₀ hours Without stabiliser 130 Compound from Example 13 1400 Compound from Example 14 1500 Compound from Example 15 1240 Example 26: (light-stabilising action in polypropylene tapes) 1 g of each of the products indicated in Table 2, 0.5 g of tris(2,4-di-t-butylphenyl) phosphite, 0.5 g of pentaerythritol tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate] and 1 g of calcium stearate are mixed in a slow mixer with 1000 g of polypropylene powder of melt index = 12 g/10 minutes (measured at 230°C and 2.16 kg). The mixtures are extruded at 200-220°C to give polymer granules which are then converted into stretched tapes of 50 µm thickness and 2.5 mm width, using a pilot-type apparatus (®Leonard-Sumirago (VA) Italy) operating under the following conditions: Extruder temperature: 210-230°C Head temperature: 240-260°C Stretch ratio: 1:6 The tapes thus prepared are exposed, mounted on a white card, in a model 65WR Weather-O-Meter (ASTM D 2565-85) with a black panel temperature of 63°C. The residual tenacity is measured on samples taken after various times of exposure to light by means of a constant-speed tensometer, and the exposure time in hours (T₅₀) needed to halve the initial tenacity is then calculated. Tapes prepared under the same conditions as indicated above, but without addition of stabilisers of the invention, are exposed for comparison. The results obtained are shown in Table 2. Stabiliser T₅₀ hours Without stabiliser 500 Compound from Example 13 2850 Compound from Example 14 2820 Compound from Example 16 2740

Claims: A compound of the formula (I) in which R₁ is hydrogen, C₁-C₈alkyl, O, OH, CH₂CN, C₁-C₁₈alkoxy, C₅-C₁₂cycloalkoxy, C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or C₁-C₈acyl, R₂ and R₃ which can be identical or different are C₂-C₃alkylene, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4, and, when n is 1, R₅ is hydrogen, C₁-C₁₈alkyl, C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or R₅ is one of the groups of the formulae (IIa)-(IIc) -COR₆ -(CO) p COOR₇ in which X₁ and X₂ which can be identical or different are a group -OR₈, -SR₈ or where R₈, R₉ and R₁₀ which can be identical or different are hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy; C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; C₂-C₄alkyl substituted in the 2-, 3- or 4-position by OH, by C₁-C₈alkoxy or by di(C₁-C₄alkyl)amino; a group of the formula in which X is a direct bond, -O-, -CH₂- or -CH₂CH₂-; tetrahydrofurfuryl or a group of the formula (III) where R₁₁ is as defined for R₁, or is 1-pyrrolidyl, 1-piperidyl, 4-morpholinyl, 4-methyl-1-piperazinyl or 1-hexahydroazepinyl, or X₁ and X₂ are one of the groups of the formulae (IVa)-(IVd) with R₁₁ as defined above, R₆ is hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₂-C₁₈alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy and/or by an OH group; C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl and/or an OH group; p is zero or 1, and R₇ is C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), and, when n is 2, R₅ is C₂-C₁₂alkylene, C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms; 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) -CO-R₁₂-CO- -COO-R₁₃-OOC- -(CH₂) q CO- in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI) where R₁, R₂, R₃ and R₄ are as defined above, E₁ is one of the groups of the formulae (VIIa)-(VIIc) -G₁-R₁₄-G₂- in which G₁, G₂ and G₃ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₇-C₉phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), R₁₄ is C₂-C₁₂alkylene, C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 groups where R₁₉ is as defined above for R₁₈ or is C₁-C₈acyl or (C₁-C₈alkoxy)carbonyl; or R₁₄ is further C₅-C₇cycloalkylene unsubstituted or substituted by C₁-C₄alkyl; C₅-C₇cycloalkylenedi(C₁-C₄alkylene), C₁-C₄alkylenedi(C₅-C₇cycloalkylene), C₂-C₄alkylidenedi(C₅-C₇cycloalkylene), phenylene unsubstituted or substituted by C₁-C₄alkyl; phenylenedi(C₁-C₄alkylene), C₁-C₄alkylenediphenylene or C₂-C₄alkylidenediphenylene, R₁₅ is C₂-C₆alkylene, G₄ is one of the groups >N-(R₁₅-G₃) s , >CH-O- or with R₁₈ as defined above, r and s which can be identical or different are zero or 1, R₁₆ is hydrogen or can also be methyl when r is 1 and G₄ is >CH-O-, and R₁₇ is hydrogen or methyl, R₁₂ is a direct bond, C₁-C₁₂alkylene, C₂-C₄alkenylene, cyclohexylene, cyclohexenylene or phenylene, R₁₃ is C₂-C₁₂alkylene, C₄-C₁₂alkylene interrupted by 1, 2 or 3 oxygen atoms, C₅-C₇cycloalkylene unsubstituted or substituted by C₁-C₄alkyl; C₅-C₇cycloalkylenedi(C₁-C₄alkylene) or C₂-C₄alkylidenedi(C₅-C₇cycloalkylene) and q is zero or an integer from 1 to 10, and when n is 3, R₅ is aliphatic C₄-C₁₈triacyl, aromatic C₉-C₁₈triacyl or a group of the formula (VIII) in which X₃ is as defined above and E₂ is one of the groups of the formula (IXa)-(IXc) R₂₆-(-O-)₃- in which G₅, G₆ and G₇ which can be identical or different are as defined above for G₁, G₂ and G₃; R₂₀, R₂₁ and R₂₂ which can be identical or different are C₂-C₆alkylene, t is zero or 1, R₂₃, R₂₄ and R₂₅ which can be identical or different are as defined above for R₁₈; G₈ is a direct bond or -CH₂-, u and v which can be identical or different are integers from 2 to 6 and R₂₆ is C₃-C₁₂alkanetriyl, and, when n is 4, R₅ is aliphatic C₆-C₁₈tetraacyl, aromatic C₁₀-C₁₈tetraacyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) in which X₃ is as defined above and E₃ is one of the groups of the formulae (XIa)-(XIc) R₂₉-(-O-)₄- in which G₉ is as defined above for G₁, G₂ and G₃; R₂₇ and R₂₈ which can be identical or different are C₂-C₆alkylene, w is zero or 1 and R₂₉ is C₄-C₁₂alkanetetrayl. A compound of the formula (I) according to claim 1, in which R₁ and R₁₁ which can be identical or different are hydrogen, C₁-C₄alkyl, OH, C₆-C₁₂alkoxy, C₅-C₈cycloalkoxy, allyl, benzyl or acetyl. A compound of the formula (I) according to claim 1, in which R₂ and R₃ which can be identical or different are C₂-C₃alkylene, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, C₁-C₁₈alkyl, C₃-C₄alkenyl, benzyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or R₅ is one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈, -SR₈ or where R₈, R₉ and R₁₀ which can be identical or different are hydrogen, C₁-C₁₈alkyl, C₅-C₈cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy; benzyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; C₂-C₃alkyl substituted in the 2- or 3- position by OH, by C₁-C₄alkoxy, by di(C₁-C₄alkyl)amino or by a group where X is a direct bond, -O-, -CH₂- or -CH₂CH₂-; tetrahydrofurfuryl or a group of the formula (III), or the group is a group as defined above, or X₁ and X₂ are one of the groups of the formulae (IVa)-(IVd), R₆ is hydrogen, C₁-C₁₇alkyl, C₅-C₈cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₂-C₁₇alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl or C₁-C₄alkoxy and/or an OH group; benzyl or phenylethyl which both are unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl and/or an OH group; p is zero or 1, R₇ is C₁-C₁₈alkyl, C₅-C₈cycloalkyl which is mono-, di- or tri-substituted by C₁-C₄alkyl; C₃-C₁₈alkenyl, benzyl which is unsubstituted or mono-, di- or trisubstituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), and, when n is 2, R₅ is C₂-C₁₀alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms; 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups of the formulae (VIIa)-(VIIc) in which G₁, G₂ and G₃ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₁₈alkyl, C₅-C₈cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; benzyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C₁-C₄alkyl; or a group of the formula (III), R₁₄ is C₂-C₁₀alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 groups where R₁₉ is as defined above for R₁₈ or is C₁-C₆acyl or (C₁-C₆alkoxy)carbonyl; or R₁₄ is further cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene, phenylene, phenylenedimethylene, methylenediphenylene or isopropylidenediphenylene, R₁₅ is C₂-C₄alkylene, G₄ is >N-(R₁₅-G₃) s -, >CH-O- or with R₁₈ as defined above, r and s which can be identical or different are zero or 1, R₁₆ is hydrogen or can also be methyl when r is 1 and G₄ is >CH-O-, and R₁₇ is hydrogen or methyl, R₁₂ is a direct bond, C₁-C₁₀alkylene, vinylene, cyclohexylene or phenylene, R₁₃ is C₂-C₁₀alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms; cyclohexylene, cyclohexylenedimethylene or isopropylidenedicyclohexylene, and q is zero or an integer from 1 to 5, and, when n is 3, R₅ is aliphatic C₄-C₁₂triacyl, aromatic C₉-C₁₂triacyl or a group of the formula (VIII) in which X₃ is as defined above and E₂ is one of the groups of the formulae (IXa)-(IXc) in which G₅, G₆ and G₇ which can be identical or different are as defined above for G₁, G₂ and G₃; R₂₀, R₂₁ and R₂₂ which can be identical or different are C₂-C₆alkylene, t is zero or 1, R₂₃, R₂₄ and R₂₅ which can be identical or different are as defined above for R₁₈; G₈ is a direct bond or -CH₂-, u and v which can be identical or different are integers from 2 to 6 and R₂₆ is C₃-C₁₀alkanetriyl, and, when n is 4, R₅ is aliphatic C₆-C₁₂tetraacyl, aromatic C₁₀-C₁₂tetraacyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) in which X₃ is as defined above and E₃ is a group of the formulae (XIa)-(XIc) in which G₉ is as defined above for G₁, G₂ and G₃; R₂₇ and R₂₈ which can be identical or different are C₂-C₆alkylene, w is zero or 1 and R₂₉ is C₄-C₈alkanetetrayl. A compound of the formula (I) according to claim 1, in which R₂ and R₃ which can be identical or different are C₂-C₃alkylene, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, methyl, C₄-C₁₈alkyl, allyl, benzyl or one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈, -SR₈ or where R₈, R₉ and R₁₀ which can be identical or different are hydrogen, C₁-C₁₂alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; allyl, undecenyl, phenyl, benzyl, C₂-C₃alkyl substituted in the 2- or 3-position by OH, by C₁-C₄alkoxy, by dimethylamino, by diethylamino or by 4-morpholinyl; tetrahydrofurfuryl or a group of the formula (III), or the group is 4-morpholinyl, or X₁ and X₂ are one of the groups of the formulae (IVa)-(IVd), R₆ is C₂-C₁₇alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; C₂-C₁₀alkenyl, phenyl, t-butylphenyl, 3,5-di-t-butyl-4-hydroxyphenyl, benzyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero or 1 and R₇ is C₂-C₁₈alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; allyl, undecenyl, oleyl, benzyl or a group of the formula (III), and, when n is 2, R₅ is C₂-C₈alkylene, C₄-C₈alkylene interrupted by 1 or 2 oxygen atoms; 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups of the formulae (VIIa)-(VIIc) in which G₁, G₂ and G₃ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₁₂alkyl, cyclohexyl which is unsubstituted or mono-, di- or tri-substituted by C₁-C₄alkyl; benzyl or a group of the formula (III), R₁₄ is C₂-C₈alkylene, C₄-C₁₀alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 groups where R₁₉ is as defined above for R₁₈ or is C₁-C₄acyl or (C₁-C₄alkoxy)carbonyl; or R₁₄ is further cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene, phenylenedimethylene or isopropylidenediphenylene, R₁₅ is C₂-C₃alkylene, G₄ is >N-(R₁₅-G₃) s - or >CH-O-, r and s which can be identical or different are zero or 1, R₁₆ is hydrogen or can also be methyl when r is 1 and G₄ is >CH-O-, and R₁₇ is hydrogen or methyl, R₁₂ is a direct bond, C₁-C₈alkylene or phenylene, R₁₃ is C₂-C₈alkylene, C₄-C₈alkylene interrupted by 1 or 2 oxygen atoms; cyclohexylenedimethylene or isopropylidenedicyclohexylene and q is zero or an integer from 1 to 3, and, when n is 3, R₅ is aliphatic C₄-C₈triacyl, benzenetricarbonyl or a group of the formula (VIII) in which X₃ is as defined above and E₂ is one of the groups of the formulae (IXa)-(IXc) in which G₅, G₆ and G₇ which can be identical or different are as defined above for G₁, G₂ and G₃; R₂₀, R₂₁ and R₂₂ which can be identical or different are C₂-C₄alkylene, t is zero or 1, R₂₃, R₂₄ and R₂₅ which can be identical or different are as defined above for R₁₈; G₈ is a direct bond or -CH₂-, u and v which can be identical or different are integers from 3 to 6 and R₂₆ is C₃-C₆alkanetriyl, and, when n is 4, R₅ is aliphatic C₆-C₈tetraacyl, benzenetetracarbonyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) in which X₃ is as defined above and E₃ is a group of the formulae (XIa)-(XIc) in which G₉ is as defined above for G₁, G₂ and G₃; R₂₇ and R₂₈ which can be identical or different are C₂-C₄alkylene, w is zero or 1 and R₂₉ is C₄-C₆alkanetetrayl. A compound of the formula (I) according to claim 1, in which R₂ and R₃ which can be identical or different are -(CH₂)₂- or -(CH₂)₃-, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, methyl, C₈-C₁₈alkyl, allyl or one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈ or where R₈ is C₁-C₈alkyl or a group of the formula (III), R₉ and R₁₀ which can be identical or different are C₁-C₈alkyl, cyclohexyl, C₂-C₃alkyl substituted in the 2- or 3-position by methoxy, by ethoxy, by dimethylamino, by diethylamino or by 4-morpholinyl; or are tetrahydrofurfuryl or a group of the formula (III), or R₉ can also be hydrogen or the group is 4-morpholinyl, R₆ is C₃-C₁₇alkyl, cyclohexyl, phenyl, 3,5-di-t-butyl-4-hydroxyphenyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero, R₇ is C₄-C₁₈alkyl, cyclohexyl, t-butylcyclohexyl or a group of the formula (III), and, when n is 2, R₅ is one of the groups of the formulae (Va)-(Ve) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups of the formulae (VIIa)-(VIIc) in which G₁ and G₂ which can be identical or different are -O- or where R₁₈ is hydrogen, C₁-C₈alkyl, cyclohexyl or a group of the formula (III), R₁₄ is C₂-C₆alkylene, C₆-C₁₀alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene or methylenedicyclohexylene, the group (VIIb) is one of the groups where r and s which can be identical or different are zero or 1, R₁₈ is as defined above and R₁₇ is hydrogen or methyl, R₁₂ is C₂-C₈alkylene or phenylene, R₁₃ is C₄-C₈alkylene or isopropylidenedicyclohexylene and q is zero or 1, and when n is 3, R₅ is a group of the formula (VIII) in which X₃ is as defined above and E₂ is a group of the formula (IXa) or (IXb) in which G₅ and G₆ which can be identical or different are as defined above for G₁ and G₂; R₂₀ and R₂₁ which can be identical or different are C₂-C₃alkylene, t is zero, R₂₃, R₂₄ and R₂₅ are as defined above for R₁₈; G₈ is a direct bond or -CH₂- and u and v which can be identical or different are integers from 3 to 5, and, when n is 4, R₅ is a group of the formula (X) in which X₃ is as defined above and E₃ is a group of the formula (XIa) in which G₉ is as defined above for G₁ and G₂; R₂₇ and R₂₈ which can be identical or different are C₂-C₃alkylene and w is zero or 1. A compound of the formula (I) according to claim 1, in which R₁ is hydrogen or methyl, R₂ and R₃ are -(CH₂)₂-, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2, 3 or 4 and, when n is 1, R₅ is hydrogen, methyl, allyl or one of the groups of the formulae (IIa)-(IIc) in which X₁ and X₂ which can be identical or different are a group -OR₈ or where R₈ is C₁-C₄alkyl, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl, R₉ and R₁₀ which can be identical or different are C₁-C₄alkyl, cyclohexyl, tetrahydrofurfuryl, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl or R₉ can also be hydrogen, or the group is 4-morpholinyl, R₆ is C₄-C₁₇alkyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero and R₇ is C₄-C₁₈alkyl, and, when n is 2, R₅ is one of the groups of the formulae (Va)-(Vd) in which X₃ is as defined above for X₁ and X₂ or is a group of the formula (VI), E₁ is one of the groups where R₁₈ is hydrogen, methyl, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl, R₁₂ is C₄-C₈alkylene or phenylene and R₁₃ is C₄-C₆alkylene, and, when n is 3, R₅ is a group of the formula (VIII) in which X₃ is as defined above and E₂ is a group where R₁₈ is as defined above, and, when n is 4, R₅ is a group of the formula (X) in which X₃ is as defined above and E₃ is a group with R₁₈ as defined above. A compound of the formula (I) according to claim 1, in which R₁ is hydrogen or methyl, R₂ and R₃ are -(CH₂)₂-, R₄ is -CO-, -COCO- or -COCH₂CO-, n is 1, 2 or 3 and, when n is 1, R₅ is hydrogen, allyl or one of the groups of the formulae (IIb) or (IIc) in which R₆ is C₄-C₁₇alkyl or 2-(3,5-di-t-butyl-4-hydroxyphenyl)ethyl, p is zero and R₇ is C₄-C₁₈alkyl, and, when n is 2, R₅ is one of the groups of the formulae (Vb) or (Vc) in which X₃ is a group of the formula (VI), E₁ is one of the groups where R₁₈ is hydrogen, 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl, R₁₂ is phenylene and, when n is 3, R₅ is a group of the formula (VIII) in which X₃ is as defined above and E₂ is a group where R₁₈ is as defined above A compound of the formula according to claim 1. A composition comprising an organic material susceptible to degradation induced by light, heat and oxidation and at least one compound of the formula (I) according to claim 1. A composition according to claim 9, wherein the organic material is a synthetic polymer. A composition according to claim 10, comprising other conventional additives for synthetic polymers in addition to the compounds of the formula (I). A composition according to claim 9, wherein the organic material is a polyolefin. A composition according to claim 9, wherein the organic material is polyethylene or polypropylene. The use of a compound of the formula (I) according to claim 1 for stabilising an organic material against degradation induced by light, heat and oxidation.

Inventors: BORZATTA VALERIO DR, VIGNALI GRAZIANO, BORZATTA, VALERIO, DR., VIGNALI, GRAZIANO
Applicants: CIBA GEIGY AG, CIBA GEIGY SPA, CIBA-GEIGY AG, CIBA-GEIGY S.P.A.
Application year: 1992
Main classification: C07D401
IPC codes: C08K5, C08L101, C07D401