Tetramethylpiperidine compounds for use as stabilizers for organic materials

A compound of the formula (I) ##STR72## in which R.sub.1 is hydrogen, C.sub.1 -C.sub.8 alkyl, O, OH, CH.sub.2 CN, C.sub.1 -C.sub.18 alkoxy, C.sub.5 -C.sub.12 cycloalkoxy, C.sub.3 -C.sub.6 alkenyl, C.sub.7 -C.sub.9 phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C.sub.1 -C.sub.4 alkyl;

• or C.sub.1 -C.sub.8 acyl, R.sub.2 and R.sub.3 which can be identical or different are C.sub.2 -C.sub.3 alkylene, R.sub.4 is --CO--, --COCO-- or --COCH.sub.2 CO--, n is 1, 2, 3 or 4, and, when n is 1, R.sub.5 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.7 -C.sub.9 phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C.sub.1 -C.sub.4 alkyl;
• or R.sub.5 is one of the groups of the formulae (IIa)-(IIc) ##STR73## in which X.sub.1 and X.sub.2 which can be identical or different are a group --OR.sub.8, --SR.sub.8 or ##STR74## where R.sub.8, R.sub.9 and R.sub.10 which can be identical or different are hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.12 cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C.sub.1 -C.sub.4 alkyl;
• C.sub.3 -C.sub.18 alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy;
• C.sub.7 -C.sub.9 phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C.sub.1 -C.sub.4 alkyl;
• C.sub.2 -C.sub.4 alkyl substituted in the 2, 3- or 4-position by OH, by C.sub.1 -C.sub.8 alkoxy, by di(C.sub.1 -C.sub.4 alkyl)amino or by a nitrogen-containing to 7-membered heterocyclic group with the free valency on the nitrogen atom;
• tetrahydrofurfuryl or a group of the formula (III) ##STR75## where R.sub.11 is as defined for R.sub.1, or ##STR76## is a 5- to 7-membered heterocyclic group, or X.sub.1 and X.sub.2 are one of the groups of the formulae (IVa)-(IVd) ##STR77## with R.sub.11 as defined above, R.sub.6 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.12 cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C.sub.1 -C.sub.4 alkyl;
• C.sub.2 -C.sub.18 alkenyl, phenyl which is unsubstituted or mono-, di- or tri-substituted by C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy and/or by an OH group;
• C.sub.7 -C.sub.9 phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C.sub.1 -C.sub.4 alkyl and/or an OH group;
• p is zero or 1, and R.sub.7 is C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.12 cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C.sub.1 -C.sub.4 alkyl;
• C.sub.3 -C.sub.18 alkenyl, C.sub.7 -C.sub.9 phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C.sub.1 -C.sub.4 alkyl;
• or a group of the formula (III), and, when n is 2, R.sub.5 is C.sub.2 -C.sub.12 alkylene, C.sub.4 -C.sub.12 alkylene interrupted by 1, 2 or 3 oxygen atoms;
• 2-hydroxytrimethylene, phenylenedimethylene or one of the groups of the formulae (Va)-(Ve) ##STR78## in which X.sub.3 is as defined above for X.sub.1 and X.sub.2 or is a group of the formula (VI) ##STR79## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as defined above, E.sub.1 is one of the groups of the formulae (VIIa)-(VIIc) ##STR80## in which G.sub.1, G.sub.2 and G.sub.3 which can be identical or different are --O-- or ##STR81## where R.sub.18 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.12 cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C.sub.1 -C.sub.4 alkyl;
• C.sub.7 -C.sub.9 phenylalkyl which is unsubstituted or mono-, di- or tri-substituted on the phenyl by C.sub.1 -C.sub.4 alkyl;
• or a group of the formula (III), R.sub.14 is C.sub.2 -C.sub.12 alkylene, C.sub.4 -C.sub.12 alkylene interrupted by 1, 2 or 3 oxygen atoms or by 1 or 2 ##STR82## groups where R.sub.19 is as defined above for R.sub.18 or is C.sub.1 -C.sub.8 acyl or (C.sub.1 -C.sub.8 alkoxy)carbonyl;
• or R.sub.14 is further C.sub.5 -C.sub.7 cycloalkylene unsubstituted or substituted by C.sub.1 -C.sub.4 alkyl;
• C.sub.5 -C.sub.7 cycloalkylenedi(C.sub.1 -C.sub.4 alkylene), C.sub.1 -C.sub.4 alkylenedi(C.sub.5 -C.sub.7 cycloalkylene), C.sub.2 -C.sub.4 alkylidenedi(C.sub.5 -C.sub.7 cycloalkylene), phenylene unsubstituted or substituted by C.sub.1 -C.sub.4 alkyl;
• phenylenedi(C.sub.1 -C.sub.4 alkylene), C.sub.1 -C.sub.4 alkylenediphenylene or C.sub.2 -C.sub.4 alkylidenediphenylene, R.sub.15 is C.sub.2 -C.sub.6 alkylene, G.sub.4 is one of the groups >N--(R.sub.15 -G.sub.3).sub.s, >CH--O-- or ##STR83## with R.sub.18 as defined above, r and s which can be identical or different are zero or 1, R.sub.16 is hydrogen or can also be methyl when r is 1 and G.sub.4 is >CH--O--, and R.sub.17 is hydrogen or methyl, R.sub.12 is a direct bond, C.sub.1 -C.sub.12 alkylene, C.sub.2 -C.sub.4 alkenylene, cyclohexylene, cyclohexenylene or phenylene, R.sub.13 is C.sub.2 -C.sub.12 alkylene, C.sub.4 -C.sub.12 alkylene interrupted by 1, 2 or 3 oxygen atoms, C.sub.5 -C.sub.7 cycloalkylene unsubstituted or substituted by C.sub.1 -C.sub.4 alkyl;
• C.sub.5 -C.sub.7 cycloalkylenedi(C.sub.1 -C.sub.4 alkylene) or C.sub.2 -C.sub.4 alkylidenedi(C.sub.5 -C.sub.7 cycloalkylene) and q is zero or an integer from 1 to 10, and when n is 3, R.sub.5 is aliphatic C.sub.4 -C.sub.18 triacyl, aromatic C.sub.9 -C.sub.18 triacyl or a group of the formula (VIII) ##STR84## in which X.sub.3 is as defined above and E.sub.2 is one of the groups of the formula (IXa)-(IXc) ##STR85## in which G.sub.5, G.sub.6 and G.sub.7 which can be identical or different are as defined above for G.sub.1, G.sub.2 and G.sub.3 ;
• R.sub.20, R.sub.21 and R.sub.22 which can be identical or different are C.sub.2 -C.sub.6 alkylene, t is zero or 1, R.sub.23, R.sub.24 and R.sub.25 which can be identical or different are as defined above for R.sub.18 ;
• G.sub.8 is a direct bond or --CH.sub.2 --, u and v which can be identical or different are integers from 2 to 6 and R.sub.26 is C.sub.3 -C.sub.12 alkanetriyl, and, when n is 4, R.sub.5 is aliphatic C.sub.6 -C.sub.18 tetraacyl, aromatic C.sub.10 -C.sub.18 tetraacyl, tetrahydrofuran-2,3,4,5-tetracarbonyl or a group of the formula (X) ##STR86## in which X.sub.3 is as defined above and E.sub.3 is one of the groups of the formulae (XIa)-(XIc) ##STR87## in which G.sub.9 is as defined above for G.sub.1, G.sub.2 and G.sub.3 ;
• R.sub.27 and R.sub.28 which can be identical or different are C.sub.2 -C.sub.6 alkylene, w is zero or 1 and R.sub.29 is C.sub.4 -C.sub.12 alkanetetrayl.