MIXTURES OF HALS COMPOUNDS

Abstract: A composition, suitable for stabilising a polymeric composition against the effects of light, comprising: a) an N-acylated 2,2,6,6-tetraalkylpiperidinyl group (hereinafter N-acylated HALS) containing compound; and b) an N-oxy-subst. 2,2,6,6-tetraalkylpiperidinyl group (hereinafter N-oxy-subst. HALS) containing compound. A further aspect of the invention relates to a composition, suitable for stabilising a polymeric composition against the effects of light comprising: a) an N-acylated 2,2,6,6-tetraalkylpiperidinyl-group-containing compound in which a spiro group is attached in the 4-position (hereinafter defined as component i); and b) an N-acylated 2,2,6,6-tetraalkylpiperidinyl-group-containing compound in which in the 4-position no spiro group is present (hereinafter defined as component ii). The compounds are suitable as light stabilizers in acid catalyzed lacquer system.

Description: MDCTORES CF HALS CCWCONDS The invention relates to novel mixtures of tetraal ylpiperidine coitpounds (HALS compounds) , suitable as light stabilisers in polymeric systems especially in acid catalysed polymeric systems. According to the invention there is provided a composition, suitable for stabilising a polymeric composition against the effects of light, comprising a) an N-acylated 2,2,6,6-tetraalkylpiperidinyl group (hereinafter - acylated HALS) containing compound; and b) an N-oxy-substituted 2,2,6,6-tetraalkylpiperidinyl group (hereinafter N-oxy-substituted HALS) containing coπpound. The term "oxy-substituted" includes substitution with any of the significances of ) below including preferably oxyalkylation. Surprisingly it has been found that by mixing an N-acylated HALS with an N-oxyalkylated HALS that a synergistic effect occurs in that the stability to light of lacquers containing a mixture of N-acylated HALS and N-oxyalkylated HALS is significantly improved over lacquers with either the N-acylated HALS or the N-oxyalkylated HALS alone. Further according to the invention there is provided a mixture comprising a) 5-95% by weight of a compound containing a group of formula I (hereinafter defined as component a) b) 5-95% by weight of a compound containing a group of formula II (hereinafter defined as component b)) in which R a is -C0-R 5 , where R 5 is C 2 -salkenyl, -C(R 3 )=CH 2 , Cι_ 2 2al yl, phenyl, -CO-phenyl, -NR 7 R 8 , -CH 2 -C 6 H 5 , -C0-0Cι_ι 2 alkyl or -C00H; R 7 is hydrogen, Cι_ι 2 alkyl, Cs-βcycloalkyl, phenyl, phenyl-Cι_ 4 alkyl or Cι_ι 2 alkylphenyl and R 8 is Cι_i2 ikyl or hydrogen, and R b is oxygen; OH; -0-C0-R 5 ; -0-Cχ_βalkyl; -O-CO-phenyl; -O-C2-βalkenyl; -0-C 3 _i 8 alkynyl; -0-C5_i2c clo alkyl; -0-C 6 -iobicycloalkyl; -0-C 5 _ 8 cyclo alkenyl, -0-C 6 _ι 0 aryl, -0-R 30 where R 30 is C _ 9 alkaryl unsubstituted or monosubstituted by Cι_ 4 alkyl or aryl; where R5 is C 2 -βalkenyl, phenyl, -CO-phenyl, -NR 7 R 8 , -CH 2 -C 6 H 5 , -CO-OCi-12alkyl or -C00H; R 3 is hydrogen or Ci-. 4 alkyl; each Ri ,- independently, is -CH 3 or -CH2 (Cι_ 4 alkyl) or both groups Ri form a group -{CH 2 )5-; and idεpcndcntly, is -CH 5 or -CH 2 (Cι_4alkyl) or both groups R 2 from a group -(CH 2 )s-; the percentages being based on the amount of component a) and b) in the mixture. Preferably R 3 is hydrogen. Preferably R 5 is R 5 ' where R 5 ' is -CH=CH 2 , Ci-aalkyl, -COOCι_ 8 alkyl, C 2 -βalkenyl or phenyl. Preferably component a) is a compound of formula III in which R a is -CO-R5; and each R 4 independently is selected from hydrogen, a hydroxy group, an ether group, an amine and amide forming group, an ester and ester forming group and a urea and urethane forming group; or both groups R 4 together with the C atom to which they are attached form a spiro group; and the other symbols are as described above. Preferably component b) is a compound of formula IV in which R b is oxygen; OH; -0-C0-R 5 ; -0-Cι_ 8 alkyl; -O-CO-phenyl; -0-C 2 - 8 alkenyl; -0-C 3 -_i 8 alkynyl; -0-C 5 _i2cyclo alkyl; -O-C 6 _i 0 bicycloalkyl; -0-C 5 _ 8 cyclo alkenyl, -0-C 6 _ 10 aryl, -0-R 30 where R 30 is C 7 _galkaryl unsubstituted or monosubstituted by Cι_ alkyl or aryi; and each R 4 independently is selected from hydrogen, a hydroxy and ether group, an amine and amide forming group, an ester and ester forming group and a urea and urethane forming group; or both groups R 4 together with the C atom to which they are attached form a spiro group; and the other symbols are as described above. Further according to the invention there is provided a composition, suitable for stabilising a polymeric composition against the effects of light, comprising a) an N-acylated 2,2,6,6-tetraalkylpiperidinyl-group-containing compound in which a spiro group is attached in the 4-position (hereinafter defined as component i) ; and b) an N-acylated 2,2,6,6-tetraalkylpiperidinyl-group-containing compound in which in the 4- position no spiro group is present (hereinafter defined as component ii) . The above composition provides significant improvements in gloss retention and reduced cracking which occurs in polymeric material containing only the individual components. It has been surprisingly found that by mixing two N-acylated HALS compounds, components i) and ii) , that a synergistic improvement in light fastness also occurs in acid catalysed systems. Preferred compounds of component i) are of formula V in which R a is -C0-R 5 ; and R 42 together with the C atom to which it is attached forms a spiro group; and the other symbols are as defined above. Preferred compounds of component ii) are of formula VI where each R 41 independently is selected from hydrogen, an a ine and amide forming group, an ester and ester forming group and a urea and urethane forming group; and Ri, R 2 and R a are as defined above. Preferably the amount of component a) (or component i) is 20-80%, more preferably 30-70%, most preferably 40-60%. Preferably the amount of component b) (or component ii) respectively) is 20-80%, more preferably 30-70%, most preferably 40-60%. Preferred cαπrpounds of formula III are those of formula Ilia to Illn in which R is a saturated or unsaturated optionally alkyl or alkenyl substituted alkylene or cycloalkylene radical having 2-20 carbon atoms; and the other symbols are as defined above; where nj is a number from 1-4 inclusive, preferably 1 or 2; R a f t and R 2 are as defined above; R 4b ; when nχ=l, is hydrogen; Cι_ι 8 alkyl, optionally interrupted by one or more oxygen atoms; cyanoethyl; benzyl, glycidyl; a monovalent radical of an aliphatic, cycloaliphatic, araliphatic or aromatic carboxylic acid or of a carbamic acid; or of a phosphorus-containing acid or a monovalent silyl radical, preferably a radical of an aliphatic carboxylic acid having 2-18 carbon atoms, of a cyloaliphatic carboxylic acid having 5-12 carbon atoms or of an aromatic carboxylic acid having 7-15 carbon atoms; R 4fa , when i is 2, is Cχ-12alkylene, C _i2alkenylene, xylylene, a bivalent radical of an aliphatic, cycloaliphatic, araliphatic or aromatic dicarboxylic acid or of a dicarbamic acid or of a phosphorus-containing acid, or a bivalent silyl radical, preferably a radical of an aliphatic dicarboxylic acid having 2-36 C atoms, of a cycloaliphatic or aromatic dicarboxylic acid having 8-14 C atoms, or of an aliphatic, cycloaliphatic or aromatic dicarbamic acid having 8-14 C atoms; R4 b when ni is 3, is a trivalent radical of an aliphatic, cycloaliphatic or aromatic tricarboxylic acid, of an aromatic tricarbamic acid or of a phosphorus-containing acid, or a trivalent silyl radical; and R 4b ; when ni is 4, is a tetravalent radical of an aliphatic, cycloaliphatic or aromatic tetracarboxylic acid; where n is the number 1 or 2 R a t Ri and R are as defined above; R 3a is hydrogen, C 1 _ι 2 alkyl, C5_ cycloalkyl, C 7 _ 8 aralkyl, C 2 _ι 8 alkanoyl, Cs-salkenoyl, benzoyl or a group of the formula CH 2 -CH(0H)-Z or of the formula -CONH-Z wherein Z is hydrogen, methyl or phenyl; R 4a , when n is 1, is hydrogen, Ci-iβ lkyl, C5_ cycloalkyl, C 2 - 8 alkenyl unsubstituted or substituted by a cyano, carbonyl or carbamide group, or it is glycidyl, a group of the formula -CH 2 -CH(0H)-Z or of the formula -CONH-Z wherein Z is hydrogen, methyl or phenyl: R 4a t when n is 2, is C 2 _ι 2 alkylene, C 6 -ι 2 arylene, xylylene, a -CH 2 -CH(0H)-CH 2 - group or a -CH 2 -CH(0H)-CH 2 -0-X-0-CH 2 -CH(0H)-CH 2 - group wherein X is C 2 -ιoalkylene, Cβ-isar lene or C6-12 cycloalkylene; or, provided that R 3a is not alkanoyl, alkenoyl or benzoyl, R a can also be a bivalent radical of an aliphatic, cycloaliphatic or aromatic dicarboxylic acid or of a dicarbamic acid, or can be the group -CO- or R 3a and R 4a together, when n is 1, can be the cyclic radical of an aliphatic or aromatic 1,2- or 1,3-dicarboxylic acid; where n is the numbej 1 or 2; R a Ri and R 2 are as defined above/ R 5a . when n is 1, is C2- 8 l ylene or hydroxyalkylene or C 4 _ 22 acyloxyalkylene; R 5a when n is 2, is the group (-CH 2 ) C(CH 2 -) 2 ; R 6 is hydrogen or both groups Rς form a group = 0; R 6a is hydrogen or both groups R 6a form a group = 0; where n is the number 1 or 2; R a , Ri and R 2 are as defined above; R 16 is hydrogen, Cι_ι 2 alkyl, allyl, benzyl, glycidyl or C 2 _ 6 alkoxyalkyl; R 17 , when n is 1, is hydrogen, Cι_ 12 alkyl, C 3 __ 5 alkenyl, C 7 _garalkyl, C 5 _ 7 cycloalkyl, C 2 _ 4 hydroxyalkyl, C 2 _ 6 alkoxyalkyl, C 6 -ιoaryl, glycidyl, a group of the formula -(CH 2 ) n -C00-Q or of the formula -(CH 2 ) m -C-C0-Q wherein m is 1 or 2, and Q is Cι_ 22 alkyl, C*t_ 22 alkenyl or phenyl; or a group of the formula -CH 2 -CH(CH 3 )-C00-Q or of the formula -CH 2 -CH(CH 3 )-O-CO-Q and Q is as defined above; R 17/ hen n is 2,is C -i2alkylene, Cg-i 2 arylene, a group -CH 2 -CH(0H)- -CH 2 -0-X-CH 2 -CH(0H)-CH 2 - wherein X is C 2 _ 10 alkylene, C 6 -ιsarylene or C 6 _ι 2 cycloalkylene, or a group -CH 2 CH-(OZ')CH 2 -(OCH 2 -CH(OZ' ) -CH 2 ) 2 - wherein Z'is hydrogen, Ci-iβalkyl, allyl, benzyl, C 2 _ι 2 alkanoyl or benzoyl; or a divalent radical of an aliphatic, cycloaliphatic, araliphtic or aromatic dicarboxylic acid; where n is the number 1 or 2 R 18 is a group of the formula where R a , Ri and R 2 are as defined above; Y is -0-; -NR 2 I; or-NR 2 ι * -C0-C0-NR 2 ι-; A is C 2 - 6 alkyiene; is the number 0 or 1; I Rig is selected from one of the groups -Rι 8 , -NR 2 ι, - 22r ~0R2 3 , -NHCH 2 0R 23 and -N(CH 2 0R 2 3)2; R 20 , when n is 1, is a group selected from Rig and Rι 9 ; R 20 , when n is 2, is the grouρ-Y-Qι~Y-, where Qi is C 2 _ 6 alkylene optionally interrupted by -N(R 2 )-; R 2 1 is hydrogen, Cl-12alkyl, cyclohexyl, benzyl or Cι_ 4 hydroxyalkyl, or a group of the formula R2 2 is C _i 2 alkyl, cyclohexyl, benzyl or Cι_ 4 hydroxyalkyl; R 23 is hydrogen, Cι_ι 2 alkyl or phenyl; R 24 is hydrogen or the group -CH 2 0R 23 ; x is an integer from 1 to 6 inclusive/ R a , Ri and R 2 are as defined above. where Q is -N(R 3 ι)- or -0-; E is Cχ_ 3 alkylene, the group -CH 2 -CH(R 34 )-0- where R 34 is hydrogen, methyl or phenyl, the group -(CH 2 ) 3 -NH- or a single bond or -CO-; R= is as defined above /.• R 32 is hydrogen or Cι_ 18 alkyl; R 3 ι is hydrogen, Ci-iβalkyl, C 5 _ 7 cycloalkyl, C 7 _ 12 aralkyl, cyanoethyl, C 6 -ιoaryl, the group -CH 2 -CH(R a )-OH where R a has the meaning defined above (when n=l), a group of the formula ■.tic s_, 6 -i-,--A--a"'-c ~_. _.» a , or ^ ^ άl a group of the formula where G can be C 2 _βalkylene or C 6 _ι 2 arylene and E, R a , R lf R 2 , R 0 and R 32 are as defined above, * where R a , R-*. and R 2 are as defined above; r ■ _. aiid S 3' , mα pendentLy arc i * .ydroq * .-__., ύι_ 30 άi 7_. ..r bonzyi or κ 33 __≤ hydrogen or Cχ_ 4 al yl and R is phenyl, (Cι_ 4 alkyl) phenyl, chlorophenyl, 4-hydroxy-3,5-t-butylphenyl or naphthyl; or R 33 and R 34 together with the carbon atoms to which they are attached form a Cs-iscycloalkylidene ring which may be unsubstituted or substituted by one Cι_ 4 alkyl group or form a group of formula R 35 is hydrogen, Cι_ 20 alkyl, C 2 _ 20 alkenyl or -CH(R 36 )-CH(R 37 )-C00R 38 where R 6 is hydrogen, methyl, phenyl or -C00Cι_ 2 ιalkyl; R 0 is as defined above; R 37 is hydrogen or methyl and R 38 is hydrogen, a Cχ_ 2 ιalkyl or C 2 _ 22 alkenyl group which may be unsubstituted or monosubstituted by phenyl or naphthyl and which may be interrupted by oxygen or by a Cι_ 4 alkylimine group; phenyl; (Cl-12alkyl) phenyl; C 5 _ 1 cycloalkyl or a saturated aliphatic hydrocarbon residue having 2-20 carbon atoms which may be interrupted by oxygen or by a Cι_ 4 alkylimine group and which is substituted by 1 to 3 groups selected from (Cι_ 2 ιalkyl)C00- and groups of the formula in which R a , Ri, R and R 3 are as defined above * X is -0-, -NH- or -N(Cι_4aikyi)- and R 40 is a saturated or unsaturated aliphatic group unsubstituted or substituted by one or two groups selected from-OH and Cι_ 4 alkoxy and which can be interrupted by an oxygen or sulphur atom; or an aromatic group, unsubstituted or substituted by one or two groups selected from -OH, Cι_ alkyl and Cι_ alkoxy; m is an intecrer of from 1 to 4 inclusive; where R a , R l r R 2 and R 3 are as defined above and R 50 is an amide or ester forming group. Preferably R 50 is an amide forming group of the formula -N(R 3 )-R 5 - L where R 5 is an aliphatic, cycloaliphatic, aromatic or heterocyclic (non-aromatic or aromatic) group, all of which may bear substituents (preferably 1 to 3) selected from Cι_ 4 alkoxy, Cι_ι 2 alkyl, Cι_ι 2 alkyl -mercapto, Cι_ι 2 alkylamino, phenoxy, phenyl mercapto, phenylamino, acryloylexy, _neth*cryloγlθ-£.y and 2,2,6, fi-fcetraalkylpipecldine groups or by oxalamido or acyloxy groups which may be further substituted by 2,2,6,6-tetraalkylpiperidine grou where the symbols are as defined above. Compounds containing groups of formula II are described in EP 309,402, the contents of which is incorporated herein by reference. Compounds of formula III and IV are known or may be made from known compounds by known methods. (Compounds of formula Ilia and IVa in which R is R r or R" are described in detail in US patent 4,356,307 and USP 4,778,837, the contents of which are incorporated herein by reference.) (Compounds of formula III! are described in USP 4,408,051 wherein R in the compounds of the said US Patent is R a of this application, the contents of which is incorporated herein by reference) . (Compounds of formula IIIj are described in US Patent 4,716,187, wherein R in the compound of the patent is R a of this application the content of which is incorporated herein by reference) (Compounds of formula Illk are describe in US Patent 4,730,017, wherein R of the compounds of this Patent is R a of the present application, the contents of which are incorporated herein by reference) . Preferred coirtDound of formula IV are those of formula IVa to IVc CH 2 CH 2 - C — X-j— R O (IVi) - H (.H 2 ) χ - CH 3 (IVk) Most preferred compounds of formula III are those of formulae IIΓ-III"' Kxo_> * nmi/υ-_c*+t- -i-Λj-.mxιιni--.- 1__-i-3_-i T __- v »7 j -4__ o_» +-u» -a • *-- v . ] -* ■ > TT7/ H 17 C 8 " ° ' S " (C 8 - C -° " C 8 H 17 (IV Preferred compounds of formula V are of formulae Hid, Ille, and Illh. Most preferred compounds of formula V are of formula III". Preferred compounds of formula VI are compounds of formula Ilia to IIIc, Illf to Illh and Illj to nin defined above. MosL preferred compounds of formula VI are of formulae III'and III"' defined above. / \ Preferably R is R' where R' is -CH(R 10 )-CH - or -(R 12 )C - C(R 12) - where R 10 is selected from C 1 2- 18 alkyl or C 12 - 18 alkenyl; cyclo C 5 -ealkylene, 1,2-cyclohexanediyl and a bicyclic divalent radical; Rn is an alicyclic or bicyclic ring system and each R 12 independently is Cι_ 4 alkyl or hydrogen. More preferably R is R" where R" is -CH(Rι 0 ')-CH 2 - where Rι 0 ' is Ci -isalkyl. Preferably R a is R a ' where R a ' is -C0R 5 ' where R 5 ' is -CH=CH 2 , _ y m . i -am.jlt.UixtjrrA v-ϋn t jfT l Preferably R 5 - is R 5 « where R 5 » is -CH=CH 2 , Cι_ alkyl or -C0-0-Cι_ 4 alkyl. Preferably R b is R b ' where R_ is -0-C0-R 5 ' where R 5 ' is defined above. Preferably each Ri and each R 2 is -CH 3 . In this Specification any C-[._ 8 alkyl or Cι_ 6 alkyl group is preferably a Cχ_4 alkyl group and any Cι_ 4 alkyl group is preferably methyl or ethyl; preferably any alkoxy group is methoxy or ethoxy. In this Specification, any group capable of being linear or branched is linear or branched. Where a symbol appears more than once in a formula, its significances are independent of one another unless indicated to the contrary. Further, according to the invention there is provided a polymeric composition comprising a polymeric material and a mixture of component a) and of component b) or a mixture of component i) and component ii) . Further according to the invention there is provided a method for stabilising a lacquer composition based on acrylic, alkyd and/or polyester resins (which if desired, can be crosslinked with melamine/formaldehyde resins, epoxide resins or polyisocyanates) which comprises incorporating into the resin a mixture of component a) and component b) or a mixture of component i) and component ii) , optionally together with an acid catalyst or compound capable of releasing an acid catalyst. Further, according to the invention there is provided a lacquer composition based on acrylic, alkyd and/or polyester resins (which if desired, can be crosslinked with melamine/formaldehyde resins, epoxide resins or polyisocyanates) containing a mixture of component a) and cc ponent b) or a mixture of com p o t i) and c p onen ii) o p ional! v together with an acid catalyst or compound capable of releasing an acid catalyst. The concentration of a mixture of component a) and component b) or a mixture of component i) and component ii) employed in the polymeric material is suitably 0.01 to 8 % by weight, preferably 0.02% to 1 % by weight and gives a clear improvement in the light- and weather-stability of organic pigments in stoving finishes as well as reducing the tendency to hairline cracking and loss of gloss as the result of weathering. This is also found for metallic finishes and excellent long-term stability of the clear top coat of two layer metallic finishes is obtained. In such finishes, the mixture of component a) and component b) or amixture of component i) and component ii) may be added to the metallic undercoat, the clear top coat or both, preferably only to the clear top coat. The metal surface to be finished may be under-coated with primer coatings as is customary in the art of coating metal surfaces. The mixture of component a) and component b) or a mixture of component i) and component ii) may be added before, during or after the polymerization step, and may be added in solid form; in solution, preferably as a liquid concentrate containing from 20 to 80 % by weight of a mixture of component a) and component b) or a mixture of component i) and component ii) and 80-20% solvent; or as a solid masterbatch composition containing 10 to 80 % by weight of a mixture of component a) and component b) or a mixture of component i) and component ii) and 90 to 20 % by weight of a solid polymeric material which is identical with or compatible with the polymeric material to be stabilized. Suitable polymeric materials include plastic materials for example polyethylene, polypropylene, ethylene/propylene copolymers, polyvinyl chloride, polyester, polyamide, polyurethane, polyacryl- onitrile, ABS, terpolymers of acrylates, styrene and acrylonitrile, styrene/acrylonitrileand styrene/butadiene. Other plastics materials such as polybutylene, polystyrene, chlorinated polyethylene, polycarbonate, polymethylmetnacrylate, poiypnenyiene oxide, polypropylene oxide; polyacetals, phenol/formaldehyde resins and epoxy resins may also be used. Preferred plastic materials are polypropylene, polyethylene, ethylene/propylene copolymers and ABS. Natural polymers for example natural rubber may also be stabilized, as may lubricating oils containing polymeric material. The mixture of a compound containing a group of formula I defined above and of a compound containing a group of formula II defined above may be incorporated by known methods into the polymeric material to be stabilized. Of particular importance is blending of the compounds with thermoplastic polymers in the melt, for example in a melt blender or during the formation of shaped articles, including foils, films, tubes, containers, bottles, fibres and foams by extrusion, injection moulding, blow moulding, spinning or wire coating. It is not essential for the polymeric material to be fully polymerised before mixing with the compounds according to the invention. The compounds may be mixed with monomer, prepolymer or precondensate, and the polymerisation or condensation reaction is carried out subsequently. This will of course be the preferred method of incorporation of the compounds into thermosetting polymers, which cannot be melt blended. Further antioxidants can be added to polymeric material either before, at the same time as or after (but before polymerisation occurs) the addition of a compound according to the invention. Examples of antioxidants include benzofuran-2-ones,indolin-2-ones and sterically hindered phenols, sulphur and phosphorus containing compounds and mixtures thereof. Preferred sterically hindered phenols include β-(4-hydroxy-3,5 -ditert.butylphenyD-propionyl stearate, methane tetrakis-(meth iene -3 (3',5'-ditert.butyl-4-hydroxy-phenyl)-propionate) , 1,3,3-tris-(2- methyl-4-hydroxy-5-tert.but l phenyl)butane, 1,3,5-tris (4-tert.butyl -3-hydroxy-2,6-di-methylbenzyl)-1,3,5-triazinyl-2,4,6 (1H, 3H,5H) -triune, bis-(4-lerL.buLyI-3-hydroxy-2,6-di-methylbenzyl)dithioi terephthalate, tris (3,5-ditert.butyl-4-hydroxybenzyl) isocyanurate, the triester of beta-(4-hydroxy-3,5-ditert.butylphenyl) propionic acid with l,3,4-tris-(2-hydroxyethyl)-5-triazinyl-2,4,6 (1H,3H,5H) -trione, bis (3,3-bis- (4'-hydroxy-3-tert.butylphenyl) -butyric acid) glycol ester, 1,3,5-trimethyl-2,4, 6-tris-(3,5-ditert.butyl-4-hydroxy -benzyl) benzene, 2,2'-methylene-bis-(4-methyl-6-tert.butylphenyl) terephthalate, 4,4-methylene-bis-(2,6-ditert.-butylphenol) , 4,4'-butylidine-bis-(tert.butylmetacresol) , 2,2'-methylene-bis- (4-methyl-6-tert.-butyl)-phenol, 1,3,5-tris-(3,5-di-t-butyl -4-hydroxyphenyl)-isocyanurate and l,l,3,tris- (5-tert.butyl-4-hydroxy -2-methylphenyl)-butane. Preferred sulphur containing antioxidative co-stabilizers which may be used include di-tridecyl-3,3-thiodipropionate, distearyl -3,3-thiodipropionate, di-lauryl-3,3-thiodipropionate, methane tetrakis (methylene-3-hexylthiopropionate) , methane tetrakis (methylene-3-dodecylthiopropionate) and dioctadecyl disulphide. Preferred phosphorus-containing co-stabilizers which may be used include trinonylphenyl phosphite, 4,9-distearyl-3,5,8,10-tetraoxa- diphosphaspiroundecane, tris- (2,4-ditert.butylphenyl) phosphite, trilauryl phosphite, bis(2,6-di-t.butyl-4-methylphenyl)pentaerythrityl -diphosphite, bis (2,4-di-t.butylphenyl) pentaerythrityl-diphosphite, distearylpentaerythrityl diphosphite and tetrakis(2,4-ditert.butyl phenyl) -4,4'-biphenylene diphosphonite. Further additives that can be added to polymeric compositions according to the invention include aminoaryl compounds, U.V. stabilisers and antistatic agents, flameproofing agents, softeners, nucleating agents, metal deactivators, biocides, impact modifiers, fillers, pigments and fungicides. Preferred aminoaryl compounds include N,N'-dinaphthyl-p-phenylene diamine and N,N'-hexamethylene-bis-3-(3,5- ditert.butyl-4-hydroxy phenyl)-propionamide. Preferred U.V. stabilisers include U.V. absorbers (e.g. 2-(2'-hydroxy- phenyl)- benztriazoles, 2-hydroxybenzophenones, l,3-bis-(2'-hydroxy- benzoyl-)benzene salicylates, cinnamates and oxalic acid diamides; U.V. quenchers such as benzoates and substituted benzoates; and hindered a ine light stabilisers (for example N-unsubstituted, N-alkyl cr N-acyl substituted 2,2,6,6-tetra-alkyl piperidine compounds) other than those of the invention. Preferably a compound of formula XX in which R 30 is C 6 - 22 alkyl or C 6 _ 2 2 alkoxy; R 3 1 and R 32 independently, are selected from hydrogen, Cι_ 8 alkyl, Cι- 12 alkoxy, Cι_i2 alkylthio, phenoxy and phenylthio provided that only one of R 3i and R 32 is alkylthio, phenoxy or phenylthio; and R 33 is hydrogen or Cι_s alkyl; is added to a compound of formula I. The mixture of component a) and component b) or mixture of component i) and component ii) are especially suitable for use in organic polymer-containing coatings, particularly automotive finishes. Automotives finishes are generally solutions or dispersion of organic polymers or polymer precursors in organic solvents. The majority are stoving finishes, which require the application of heat, generally above 80°C, on order to harden the finish in an acceptable time once it has been applied to the primer-coated metal surface. The hardening step may be accelerated by the use of an acid catalyst. The effect of this heating may be to accelerate the chemical reaction between polymer precursors in a thermosetting system, or to bring about fusion of particles of a thermoplastic polymer. Many automotive finishes are metallic finishes, which contain flakes of metal, usually aluminium, in order to provide optical effects due to reflection. Such finishes are often two-coat finishes, in which a clear top coat finish is applied over a base coat finish containing a single pigment and/or metal flakes. The compounds of formula I can be in the top coat finish or the ground coat finish, preferably the former. Such two-coat metallic finishes have particular need to U.V.-stabilizers in the top coat, since the polymer in this coat is not protected by light-absorbing pigments, and it is subjected to almost double the normal amount of radiation because of reflection of light from the lower metallic layer. The mixture of component a) and component b) or mixture of component i) and component ii) are suitable for use as U.V.-stabilizers in a wide range of liquid finishes, for example those based on combinations of elamine-formaldehyde resins with oil-modified polyester resins, polyacrylate resins with added crosslinkers, or saturated polyesters; or on self-crosslinked polyacrylate or polyacrylate resin co-polymerised with styrene. Further examples are two-component finishes based on an aliphatic or aromatic di-isocyanate and a hydroxy-group-containing polyacrylate, polyester or polyether resin. These polyurethane 2-component finishes are preferably hardened at 60 to 120°C. Thermoplastic polyacrylate resins may also be used, the latter being particularly useful in metallic finishes, as are also polyacrylate resins with added crosslinkers in combination with melamine-formaldehyde resins etherified with butanol and, further, hydroxy-group-containing polyacrylate resins are described in USP 3,062,753, the contents of which are incorporated herein by reference. The mixture of component a) and component b) or mixture of component i) and component ii) are particularly useful in acid catalysed stoving finishes particularly in the top coat of two metallic finishes. The mixture of component a) and component b) or mixture of component i) and component ii) may be added to the finish at any stage in its manufacture, and may be added in solid form or in solution, preferably in the form of a liquid concentrate in a suitable solvent or in the form of a dispersion in water or organic solvent. In practice the mixture υf component a) and component b) or mixture of component i) and component ii) are added to a finish as a solution in organic solvent (as a liquid finish) in which the binder material is between 35 % (low solid finishes) and 70 % by weight (high solid finishes) . The binder material of the finish can be in aqueous emulsion or suspension form (as an aqueous finish) in which the binder material part makes up 20 to 30 % by weight. However, the mixture of component a) and component b) or of component i) and of component ii) can be added to known powder finishes. The mixture of component a) and component b) or mixture of component i) and component ii) are to be added to the liquid or powder finishes - before stoving or hardening. Preferably the mixture of component a) and component b) or mixture of component i) and component ii) are used in liquid finishes since it is easy to add exact dosages. It is particularly preferred to use a concentrate (preferably in a hydrocarbon solvent) containing at least 40 % preferably 60 to 80 % by weight of the total weight of the concentrate of the mixture of component a) and component b) or mixture of component i) and component ii) to finishes for stoving. The compounds of the invention can also be used in photopolymeric substrates containing photoinitiators for the photopolymerisation. The invention will now be illustrated by the following Examples in which all parts and percentages are by weight and all temperatures are in °C. The amount of light stabilizer is based on the solids weight in the lacquers Example 1 A 2 layer metallic coating comprising a base coat and a clear top coat can be prepared from the follow lacquers. Base coat lacquer 18.75% of clear cloat lacquer 1 defined below (50% solids) 51.75% of a cellulose - acetobutyrate solution (20%) commerically available as Cellit BP 500 13.54% of n-butyl acetate 6.45% of xylene 5.15% of ethylene glycol acetate 0.26% of anti-sedimenting medium: Aerosil 200 3.85% of a 65% aluminium parte in ethylene glycol acetate commerically available as Alcoci 7530 0.25% of Phthalocyanine Blue (C.I. Pigment Blue 15:1) 100.00% (the ratio of the pigment ot aluminium being about 1:10) Clear coat lacquer 1 is formulated as follows: 80.00% of an acrylic resin, commercially available as Viacryl SC344 - a 50% in a solution of xylene and n-butanol (4:1 ratio) 13.90% of melamine resin 4.10% of n-butanol and 2.00% of a diluent commercially available as Byketol OK. Procedure of preparing the two coat lacquer coating: A 10 x 30 cm primed aluminium piece is coated wet on wet with the base coat lacquer and then the clear coat lacquer, to which 1% of a 50:50 mix of the compound of formula la and lb 25 la CH. has been applied to give a 15μ base coating and a 35 μ clear coating. The so treated aluminium piece is then stoved at 140°C for 35 minutes. Example 2 A two layer metallic coating comprising a base coat and a clear top coat can be prepared from the following lacquers. a) Base coat lacquer: 18.75% of the clear lacquer 1 defined below (50% solids); 51.75% of a cellulose-acetobutyrate solution (20%) commercially available as CELLIT BP 500; 13.54% of n-butyl acetate; 6.45% of xylene; 5.15% of ethylene glycol acetate; 0.26% of an anti-sedimenting agent medium: AEROSIL 200; 3.85% of a 65% aluminium paste in ethylene glycol acetate commercially available as ALCOCI 7530; and 0.25% of Phthalocyanaine Blue (CI Pigment Blue 15:1). 100.00% the ratio of the pigment to aluminium being about 1:10. b) Clear coat lacquer 1 is formulated as below: 57.50% of PARALOID AT 400 70% (Acrylic binder from Rohm and Haas); 18.20% of CYMEL 1130 (Melamine binder from Dyno Lyamann) ; 1.50% of BXK 306 (10% solution in Exxaffe 600 BYK Chemicals); 21.60% Exxate 600 (Solvent from Eno Chemicals); 1.20% CYCAT 4045 (Blocked acid catalyst from Dyno Cyanamid) . A 10 x 30 cm primed aluminium piece is coated wet on wet with the base coat lacquer and then the clear coat lacquer to which Z% of a 50:50% mixture of compounds of formula la and lb has been applied to give a 15μ base coating and a 35μ clear coating. The so-treated aluminum piece is then stoved at 140°C for 35 minutes. Examples 3 and 4 Examples 1 and 2 are repeated using, instead of the compound of formula la, 2% of a 50:50 mix of the compound of formula lb defined in Example 1 and the compound of formula 3a (Example 3) or 2% of a 50:50 mix of the compound of formula lb defined in Example 1 and the compound of formula 4a (Example 4) Example 5 Examples 1 to 3 are repeated using additionally 1% of a U.V. absorber of the formula 5a with the mixture of compounds of formula la and lb, defined in Example Example 6 Examples 1 to 4 can be repeated in which 2.2% (actives) of the monobutylester of maleic anhydride are added to the clear lacquer; and instead of stoving at 140°C for 35 minutes the lacquer is acid cured at 90°C for 30 minutes. Example 7 Examples 1 and 2 are repeated using instead of the mixture of compounds of la and lb, 1% of a 50.50 mixture of compounds la and 3a (without any of the compound of formula lb present) . Examples 8 and 9 Examples 1 and 2 are repeated using instead of the mixture of compounds of formula la and lb, 1% of a 50:50 mixture of the compound of formula la and the compound of formula 3a; (Example 6) and 1% of a 50:50 mixture of the compound of formula la and the compound of formula 4a Example 10. A two layer coating in which the top coat is 2C-PUR can be prepared as follows: A base coat lacquer is formulated as in Example 1. A clear lacquer is prepared as follows: ' Λ -P -i vπ ■ *-- ■ -* * * ■ *. P—DTTD ΛΛmrM- i ppr 44.1% of a hydroxy-group-containing acrylic resin (OH number about 150) commercially available as Macrynal SM 510 N, a 60% solution in xylene and ethylene glycol acetate (ratio 4:1) 35.2% of a diluent mixture of methylethyl ketone and xylene (1:1) 3.0% of Byketol spezial: commercially available (silicone containing) levelling agent. The second component comprises 17.7% of an aliphatic polyisocyanate commercially available as Desmodin N (which is a 75% solution in xylene / ethylene glycol acetate 4:1). The second component is then added to the first component and (defined above) mixed wet. To the 2C PUR so formed, 1% of a 50:50 mixture of a compound of formula la and lb (defined in Example 1) is applied. The base and clear lacquers (at the same thicknesses as in Example 1) are applied to an aluminium piece wet on wet as described in Example 1. The lacquers are then stoved at 80°C for 35 minutes. Example 10 can be repeated using 1% of any one of the compounds of formula la or 1 b with compounds 3a or 4a (defined above) .

Claims: What is claimed is: 1. A composition, suitable for stabilising a polymeric coπposition against the effects of light, comprising a) an N-acylated 2,2,6,6-tetraalkylpiperidinyl group (hereinafter /V-acylated HALS) containing compound; and b) an N-oxy-substituted 2,2,6,6-tetraalkylpiperidinyl group (hereinafter N-oxy-substituted HALS) containing con-pound. 2. A composition comprising a) 5-95% by weight of a compound containing a group of formula I (hereinafter defined as component a) b) 5-95% by weight of a coπpound containing a group of formula II (hereinafter defined as component b) ) in which a iS -CO-R5, where R 5 is where R 5 is C 2 -salkenyl, -C(R 3 )=CH 2 , Cι_ 22 al yl, phenyl, -CO-phenyl, -NR 7 R 8 , -CH 2 -C 6 H 5 , -C0-0Cχ_ 12 alkyl or -COOH; R is hydrogen, Cι_ 12 alkyl, C 5 _ 6 cycloalkyl, phenyl, phenyl-Cι_ 4 - alkyl or Cι_i2alkylphenyl and R 8 is C 1 _ι 2 alkyl or hydrogen, and R b is oxygen; OH; -0-C0-R 5 ; -0-Cι_ 8 alkyl; -O-CO-phenyl; -0-C 2 -salkenyl; -0-C 3 _ι 8 alkynyl; -0-C 5 _ι 2 cyclo alkyl; -0-C 6 -ιobicycloalkyl; -0-C 5 _ 8 cyclo alkenyl, -0-C 6 _ 10 aryl, -0-R 30 where R 3 o is C-y-galkaryl unsubstituted or monosubstituted by Cι_ 4 alkyl or aryl; where R5 is C 2 - 8 alkenyl, -C(R 3 )=CH 2 (preferably), C 1 _ 22 alkyl, phenyl, -CO-phenyl, -NR 7 R 8 , -CH 2 -C 6 H 5 , -C0-0C 1 _ 12 alkyl or -COOH; R is hydrogen or Cι_ 4 alkyl; each Ri, independently, is -CH 3 or -CH 2 (Cι_4alkyl) or both groups R form a group -(CH 2 )s-; and each R 2 , independently, is -CH 3 or -CH 2 (Cι_ 4 alkyl) or both groups R 2 from a group -(CH 2 )s-; the percentages being based on the amount of component a) and b) in the mixture. 3. A composition according to any one of the preceding claims in which a) component a) is a compound of formula III in which R a is -C0-R 5 ; and each R 4 independently is selected from hydrogen, a hydroxy group , an ether group, an amine and amide forming group, an ester and ester forming group and a urea and urethane forming group; or both groups R 4 together with the C atom to which they are attached form a spiro group; and b) component b is a compound of formula IV in which R b is oxygen; OH; -0-C0-R 5 ; -0-Cι_βalkyl; -0-CO-phenyl; -O-C2- 8 alkenyl; -0-C 3 _ιsalkynyl; -0-C5_ι 2 cyclo alkyl; -O-Cβ-iobicycloalkyl; -0-C 5 _ 8 cyclo alkenyl, -0-Cβ-ιoaryl, -0-R 30 where R 3 o is C 7 -.galkaryl unsubstituted or monosubstituted by Cι_ 4 alkyl or aryl; and each R 4 independently is selected from hydrogen, an amine and amide forming group, an ester and ester forming group and a urea and urethane forming group; or both groups R 4 together with the C atom to which they are attached form a spiro group; and the other symbols are as described in Claim 1. 1. A composition according to Claim 3 in which the compound of formula III is of formula Ilia to Illn and the compound of formula IV is of formula IVa to IVn in which R is a saturated or unsaturated optionally alkyl or alkenyl substituted alkylene or cycloalkylene radical having 2-20 carbon atoms; and the other symbols are as defined above; where ni is a number from 1-4 inclusive, preferably 1 or 2; Λ a R and R2 are as defined £ n claim 2, R 4b . when nι=l, is hydrogen; Cι_ι 8 alkyl, optionally interrupted by one or more oxygen atoms; cyanoethyl; benzyl, glycidyl; a monovalent radical of an aliphatic, cycloaliphatic, araliphatic or aromatic carboxylic acid or of a carbamic acid; or of a piiospiiorus—containing aci . or a onovaxeni, si y_ rauicax, preferably a radical of an aliphatic carboxylic acid having 2-18 carbon atoms, of a cyloaliphatic carboxylic acid having 5-12 carbon atoms or of an aromatic carboxylic acid having 7-15 carbon atoms; R 4b ; when r_ι is 2, is Cι_ι 2 alkylene, C 4 _ι 2 alkenylene, xylylene, a bivalent radical of an aliphatic, cycloaliphatic, araliphatic or aromatic dicarboxylic acid or of a dicarbamic acid or of a phosphorus-containing acid, or a bivalent silyl radical, preferably a radical of an aliphatic dicarboxylic acid having 2-36 C atoms, of a cycloaliphatic or aromatic dicarboxylic acid having 8-14 C atoms, or of an aliphatic, cycloaliphatic or aromatic dicarbamic acid having 8-14 C atoms; R 4b , when n x is 3, is a trivalent radical of an aliphatic, cycloaliphatic or aromatic tricarboxylic acid, of an aromatic tricarbamic acid or of a phosphorus-containing acid, or a trivalent silyl radical; and R 4b , when ni is 4, is a tetravalent radical of an aliphatic, cycloaliphatic or aromatic tetracarboxylic acid; where n is the number 1 or 2 R a Ri and R 2 are as defined above; κ 3a is hydrogen, Cι_ι 2 aikyi, C 5 .- 7 cycioaikyi, c _ 8 aralkyl, C 2 _ι 8 alkanoyl, C 3 _ 5 alkenoyl, benzoyl or a group of the formula CH 2 -CH(0H)-Z or of the formula -CONH-Z wherein Z is hydrogen, methyl or phenyl; R 4a . when n is 1, is hydrogen, Cι_ι 8 alkyl, C 5 _ 7 cycloalkyl, C 2 - 8 alkenyl unsubstituted or substituted by a cyano, carbonyl or carbamide group, or it is glycidyl, a group of the formula -CK 2 -CH(0H)-Z or of the formula -CONH-Z wherein Z is hydrogen, methyl or phenyl: R.a , wnen n is 2, is C 2 _ι 2 alkylene, C 6 _ι 2 arylene, xylylene, a -CH 2 -CH(0H)-CH 2 - group or a -CH 2 -CH(OH) -CH 2 -0-X-0-CH 2 -CH(0H)-CH 2 - group wherein X is C 2 -ιo lkylene, Cg-isarylene or C6-12 cycloalkylene; or, provided that R 3a is not alkanoyl, alkenoyl or benzoyl, R 4a can also be a bivalent radical of an aliphatic, cycloaliphatic or aromatic dicarboxylic acid or of a dicarbamic acid, or can be the group -CO- or R 3a and R 4a together, when n is 1, can be the cyclic radical of an aliphatic or aromatic 1,2- or 1,3-dicarboxylic acid; where n is the number 1 or 2; R a . Ri and R 2 are as defined above ( . Rs a t when n is 1, is C 2 -aalkylene or hydroxyalk lene or C 4 _ 2 acyloxyalk lene; R5a * when n is 2, is the group (-CH 2 ) 2 C(CH 2 -)2/' R 6 is hydrogen or both groups R 6 form a group = 0; R 6a is hydrogen or both groups Rg a form a group = 0; where n is the number 1 or 2; R a , Ri and R 2 are as defined above; Riβ is hydrogen, Cι_ι 2 alkyl, allyl, benzyl, glycidyl or C 2 _ 6 alkoxyalkyl; R 17 t when n is 1, is hydrogen, Cι_ι 2 alkyl, C 3 _ 5 alkenyl, C 7 _ 9 aralkyl, C5_ 7 cycloalkyl, C2- 4 hydroxyalkyl, C2-βalkoxyalkyl, Cβ-ioaryl, glycidyl, a group of the formula -(CH 2 ) n -COO-Q or of the formula -(CH 2 ) m -0-C0-Q wherein m is 1 or 2, and Q is Ci_2 2 lkyl, Cι._ 22 alkenyl or phenyl; or a group of the formula -CH 2 -CH(CH 3 )-C00-Q or of the/formula -CH 2 -CH(CH 3 ) -0-CO-Q and Q is as defined above; Rι 7 ,when n is 2 is C 2 _ι 2 alkylene, C 6 -i2arylene, a group -CH 2 -CH(0H)—CH 2 -0-X-CH 2 -CH(0H)-CH 2 - wherein X is C 2 _ι 0 alkylene, C 6 _i5arylene or C 6 -i2cy c lo lk lene, or a group -CH 2 CH-(0Z')CH2-(0CH 2 -CH(0Z')-CH 2 )2- wherein Z'is hydrogen, Cι_ι 8 alkyl, allyl, benzyl, C 2 -i2alkanoyl or benzoyl; or a divalent radical of an aliphatic, cycloaliphatic, araliphtic or aromatic dicarboxylic acid; : where n is the number 1 or 2; Ri 3 is a group of the formula where R a , Ri and R 2 are as defined above; Y is -0-; -NR 2 ; or-NR 2 ι-C0-C0-NR 2 ι-; A is C 2 _ 6 alkylene; is the number 0 or 1; H I Rig is selected from one of the groups -Ris. -NR 2 ι, -R 22f "0R 23 , -NHCH 2 0R 23 and -N(CH 2 0R 23 )2; R 2 o r when n is 1, is a group selected from Rι 8 and Rι 9 ; R2 0f when n is 2, is the group-Y-Qi-Y-, where Qi is C 2 - 6 alkylene optionally interrupted by -N(R 24 )-; R 2 1 is hydrogen, Cl-12alkyl, cyclohexyl, benzyl or Cι_ 4 hydroxyalkyl, or a group of the formula R 22 is Cι_ι 2 alkyl, cyclohexyl, benzyl or Cι_ hydroxyalkyl; R 3 is hydrogen, Cι_ι 2 alkyl or phenyl; R 24 is hydrogen. or the group -CH 2 0R 23 ; *a — » Q—E—CO—KM- CH ? -^ X 0R 12 dug ) x is an integer from 1 to 6 inclusive, * R a , Ri and R are as defined above t where Q 2 is -N(R 3i )- or -0-; E is Cι_ 3 alkylene, the group -CH 2 -CH(R 34 )-0- where R 34 is hydrogen, methyl or phenyl, the group -(CH 2 ) 3 -NH- or a single bond or -CO-; R a is as defined above . R 3 2 is hydrogen or Cι_ι 8 alkyl; R 31 is hydrogen, Ci-iβalkyl, C 5 _ 7 cycloalkyl, C _i2aralkyl, cyanoethyl, C 6 _ιoaryl, the group -CH 2 -CH(R 4a )-0H where R 4a has the meaning defined above (when n=l), a group of the formula where R 0 has a significance of R a ; or a group of the formula where G can be C 2 - 6 alkylene or C 6 _ι 2 arylene and E, R a , R , R 2 , RQ and R 32 are as defined above. where R a , Ri and R 2 are as defined above; R 33 and R 34 independently are hydrogen, Cι_ 3 oalkyl or benzyl or Ω . e Vι .τHrΛrror> AT- P. . a 1 V .rl an. . R . © nhanvl IC . α * l V-τrl \ ΠIIΛTH. 1 chlorophenyl, 4-hydroxy-3,5-t-butylphenyl or naphthyl; or R 33 and R 34 together with the carbon atoms to which they are attached form - - a Cs-iscycloalkylidene ring which may be unsubstituted or substituted by one Cι_ 4 alkyl group or form a group of formula R 35 is hydrogen, Cι_ 2 oalkylf C 2 -2oalkenyl or -CH(R 36 )-CH(R 37 )-C00R 38 where R 36 is hydrogen, methyl, phenyl or -COOCi_2ialkyl; Ro is as defined above; R 37 is hydrogen or methyl and R 3 β is hydrogen, a Cι_2ialkyl or C 2 -22 a l ken y group which may be unsubstituted or monosubstituted by phenyl or naphthyl and which may be interrupted by oxygen or by a Cι_4alkylimine group; phenyl; (Cl-12alkyl) phenyl; C5_i2cycloalkyl cr a saturated aliphatic hydrocarbon residue having 2-20 carbon atoms which may be interrupted by oxygen or by a Cι_ 4 alkylimine group and which is substituted by 1 to 3 groups selected from (Cι_ 2 ιalkyl)C00- and groups of the formula )—CH(R 37 )—COO— CH 2 CH Z — C — ~ ϋ (Illi) in which R a , Ri, R2 and R 3 are as defined above - X is -0-, -NH- or -N(Cι_ 4 alkyl)- and R 40 is a saturated or unsaturated aliphatic group unsubstituted or substituted by one or two groups selected from-OH and C 1 -. 4 alkoxy and which can be interrupted by an oxygen or sulphur atom; or an aromatic group, unsubstituted or substituted by one or two groups selected from -OH, Cι_ 4 alkyl and Cι_ 4 alkoxy; is an integer of from 1 to 4 inclusive; where R a , Ri, 2 and R 3 are as defined above and R 50 is an amide or ester forming group." (CH _' X - CH. dllk) where the symbols are as defined abovej -48- 32 (IVh) a o (IVi) (VII) where the symbols are as defined above or are defined in Claim 1. A composition according to Claim 4 or 5 in which the compound of formula III is of formula III' to III" ' and the compound of formula IV is of formula IV 7. A composition, suitable for stabilising a polymeric composition against the effects of light, comprising a) an N-acylated 2,2,6, 6-tetraalkylpiperidinyl-group-contair.ing compound in which a spiro group is attached in the 4-position (hereinafter defined as component i) ; and b) an N-acylated 2,2,6, 6-tetraalkylpiperidinyl-group-containing compound in which in the 4- position no spiro group is present (hereinafter defined as component ii) . 8. A composition according to Claim 7 in which i) component i) is a compound of formula V Ra. is -C0-R 5 ; R 4 2 together with the C atom to which it is attached form a spiro group; and ii) component ii) is a compound of formula VI where each R 41 independently is selected from hydrogen, an amine and amide forming group, an ester and ester forming group and a urea and urethane forming group; and the other symbols are as defined in Claim 2. 9. A polymeric composition comprising a polymeric material and a mixture of component a) and of component b) defined in Claims 1 to6 or of component i) and of component ii) defined in Claims 7 or 8. 10. A method for stabilising a lacquer composition based on based on acrylic, alkyd and/or polyester resins (which if desired, can be crosslinked with melamine/formaldehyde resins, epoxide resins or polyisocyanates) which comprises incorporating into the resin a a mixture of component a) and of component b) defined in Claims 1 to β or of component i) and of component ii) defined in Claims 7 or 8, optionally together with an acid catayst or compound capable of releasing an acid catalyst. 11. A lacquer composition based on acrylic, alkyd and/or polyester resins (which if desired, can be crosslinked with melamine/formaldehyde resins, epoxide resins or polyisocyanates) containing a mixture of component a) and of component b) defined in Claims 1 to 6 or of component i) and of component ii) defined in Claims 7 or 8, optionally together with an acid catayst or compound capable of releasing an acid catalyst. 12. A mixture comprising a) 10-90% by weight of a compound containing a group of formula I (hereinafter described as component a) b) 10-90% bv of formula II (hereinafter described as component b) ) in which R a is -C0-R 5 , where R 5 is defined in Claim 3, R b is oxygen; OH; -0-C0-R 5 ; -0-Cι_ 8 alkyl; -O-CO-phenyl; -0-C 2 - 8 alkenyl or -COR5; -0-C 3 _ι 8 alkynyl; -0-C 5 _ι 2 cyclo alkyl; -0-C 6 -ιobicycloalkyl; -0-C 5 -. 8 cyclo alkenyl, -0-C 6 _ 10 aryl, -0-R 30 where R 30 is C 7 _ 9 alkaryl unsubstituted or monosubstituted by C ! _ 4 alkyl or aryl; where R 5 is C 2 - 8 alkenyl, -C(R 3 )=CH 2 (preferably), Ci-^alky- 1 -, phenyl, -CO-phenyl, -NR 7 R 8 , -CH 2 -C 6 K 5 , -CO-OCi_i 2 alkyl or -COOH; R 7 is hydrogen, Cι_ι 2 alkyl, C 5 _ 6 cycloalkyl, phenyl, phenyl-Cι_ 4 alkyl or Cι_ι 2 alkylphenyl and R 8 is Cι_ι 2 alkyl or hydrogen, and R 3 is hydrogen or Cι_ 4 alkyl; each R x , independently, is -CH 3 or -CH2 (Cι_ 4 alkyl) or both groups Ri form a group -(CH 2 ) 5 -; and each R 2 , independently, is -CH 3 or -CH 2 (Cι_ 4 alkyl) or both groups R 2 from a group -(^ 2 )5-, 13. The use of a mixture according to Claim 12 to stabilize an acid catalysed polymeric lacquer against the effects of light whilst at the same time providing good hardening properties.

Inventors: BECHTOLD KARL, LIGNER GILBERT, WOLF RAINER, BECHTOLD, KARL, LIGNER, GILBERT, WOLF, RAINER
Applicants: SANDOZ AG, SANDOZ LTD, SANDOZ LTD., SANDOZ-PATENT-GMBH
Application year: 1992
Main classification: C09D7
IPC codes: C08K5, C08L101, C09D7