Novel light stabilizers

A compound of formula I ##STR45## wherein M.sup.q .sym. is a metal ion carrying a double or triple positive charge and q is 2 or 3 and r is 1 or 2, the quotient q/r being 1, 1.5, 2 or 3, and L is a piperdine, which is substituted by at least one enolate group in the 1-position or 4-position and wherein the ring nitrogen is sterically hindered by alkyl substituents in the adjacent positions, having the formula II ##STR46## in which R.sub.1 is hydrogen or C.sub.1 -C.sub.4 alkyl and Z.sub.1 is hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.8 alkenyl, C.sub.3 -C.sub.4 alkynyl, C.sub.2 -C.sub.21 alkoxyalkyl, C.sub.7 -C.sub.8 aralkyl, an aliphatic acyl group having 1-4 C atoms, or one of the groups --CH.sub.2 COOR.sub.2 or --CH.sub.2 --CH(R.sub.3)--OR.sub.4, or a --(CH.sub.2).sub.4 --R.sub.5, --CH.sub.2 --CH.dbd.CH--CH.sub.2 --R.sub.5, ##STR47## radical or a group of the formula III ##STR48## in which R.sub.2 is C.sub.1 -C.sub.8 alkyl, C.sub.3 -C.sub.6 alkenyl, phenyl, C.sub.7 -C.sub.8 aralkyl or cyclohexyl and R.sub.3 is hydrogen, methyl or phenyl and R.sub.4 is an aliphatic C.sub.1 -C.sub.18 acyl group, an aromatic C.sub.7 acyl group, an araliphatic C.sub.8 -C.sub.9 acyl group or an alicyclic C.sub.6 -C.sub.9 acyl group, in which the aromatic part can be unsubstituted or substituted by chlorine, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.8 alkoxy and/or hydroxy, and R.sub.5 is a group of the formula IV ##STR49## in which Z.sub.2 and Z.sub.3 are as defined below, and R.sub.6 is a group of the formula V ##STR50## in which R.sub.9 is hydrogen or C.sub.1 -C.sub.4 alkyl, and R.sub.7 and R.sub.8 independently of each other are hydrogen, methyl, phenyl, C.sub.2 -C.sub.9 alkoxymethyl or a --CH.sub.2 --O--R.sub.6 radical, in which R.sub.6 is as defined above, and a is 0, 1 or 2 and b is 0 or 1 and c is 0 or, if a and/or b differ from 0, is also 1, and X and Y independently of each other are --O-- or ##STR51## in which R.sub.10 is hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.8 alkenyl, cyclohexyl, C.sub.3 -C.sub.21 alkoxyalkyl, C.sub.7 -C.sub.13 aralkyl, phenyl which is unsubstituted or substituted by C.sub.1 -C.sub.8 alkyl and/or C.sub.1 -C.sub.8 alkoxy, or a group --CH.sub.2 --CH.sub.2 --O--R.sub.6, in which R.sub.6 is as defined above, and Z.sub.2 is hydrogen, C.sub.2 -C.sub.18 aliphatic acyloxy, benzoyloxy which is unsubstituted or substituted by C.sub.1 -C.sub.8 alkyl or C.sub.1 -C.sub.8 alkoxy, or C.sub.2 -C.sub.18 acylamido group which is unsubstituted or C.sub.1 -C.sub.8 N-alkylsubstituted, or one of the groups --R.sub.12, --(CH.sub.2).sub.d --R.sub.12, ##STR52## in which d is 2 to 10 and R.sub.12 is a group of the formula VII ##STR53## in which R.sub.1 and Z.sub.1 are as defined above, or Z.sub.2 is also a group of the formula VIII ##STR54## in which R.sub.12 is as defined above and X' is --O-- or ##STR55## in which R.sub.14 is hydrogen or C.sub.1 -C.sub.4 alkyl, and R.sub.13 is --(CH.sub.2).sub.e -- or a group ##STR56## in which e is 0 to 8 and R.sub.15 and R.sub.16 independently of one another are hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.3 -C.sub.8 alkenyl, C.sub.7 -C.sub.11 aralkyl, cyanomethyl, cyanoethyl or a group --CH.sub.2 COOR.sub.17, in which R.sub.17 is methyl or ethyl, or Z.sub.2 is one of the groups ##STR57## in which R.sub.6, R.sub.7 and R.sub.12 are as defined above and R.sub.18 is hydrogen, C.sub.1 -C.sub.8 alkyl, allyl, phenyl or benzyl and R.sub.19 is hydrogen, C.sub.1 -C.sub.8 alkyl, allyl or benzyl and R.sub.20 is C.sub.1 -C.sub.4 alkyl or a group of the formula V which is as defined above, and R.sub.21 is C.sub.2 -C.sub.6 alkylene, cyclohexylidene, phenylene, diphenylene, 4,4'-diphenylene oxide or 4,4'-diphenylenemethane, or Z.sub.2 is also a group of the formulae XII, XIII or XIV ##STR58## in which a, b, c, X, Y, R.sub.6, R.sub.7 and R.sub.8 are as defined above and f, a' and b' are 0 or 1 and g is 0 or, if a' and/or b' differ from 0, is also 1, and R.sub.22 and R.sub.23 independently of one another are hydrogen, C.sub.1 -C.sub.4 alkyl, cyclohexyl, phenyl, benzyl, .alpha.-methylbenzyl or .alpha.,.alpha.-dimethylbenzyl, and Z.sub.3 is hydrogen or cyano, or Z.sub.2 and Z.sub.3 together are one of the groups XV, XVI or XVII ##STR59## in which R.sub.6 is as defined above and R.sub.24 is hydrogen, methyl or ethyl and R.sub.25 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.3 -C.sub.8 alkenyl, cyclohexyl, C.sub.7 -C.sub.8 aralkyl or a group --CH.sub.2 --COOR.sub.26 or --CH.sub.2 --CH(R.sub.8)--O--R.sub.6, in which R.sub.26 is C.sub.1 -C.sub.18 alkyl and R.sub.6 and R.sub.8 are as defined above, and m is 0, 1 or 2 and A is H.sub.2 O or an amine of the formula (XVIII) ##STR60## in which R.sub.27 is substituted or unsubstituted alkyl, cycloalkyl, aryl or aralkyl, a substituted or unsubstituted aminoalkyl or piperidinyl group, and R.sub.28 is hydrogen or substituted or unsubstituted alkyl or cycloalkyl, a substituted or unsubstituted aminoalkyl group or a piperidinyl group, or R.sub.27 and R.sub.28 together with the N atom form a pyrrolidine, piperidine or morpholine ring which is substituted by alkyl groups or is unsubstituted, and R.sub.29 is hydrogen or substituted or unsubstituted alkyl.