GB2349151A - Stabilizer mixtures for polyolefins - Google Patents

Abstract

A stabilizer mixture contains<BR> A) for example at least one compound of the formula (III) <EMI ID=1.1 HE=67 WI=128 LX=240 LY=623 TI=CF> <BR> <PC>wherein the radicals R<SB>4</SB>, independently of one another, are hydrogen, C<SB>1</SB>-C<SB>8</SB>alkyl, -O; -CH<SB>2</SB>CN, C<SB>3</SB>-C<SB>6</SB>alkenyl, C<SB>7</SB>-C<SB>9</SB>phenylalkyl, C<SB>7</SB>-C<SB>9</SB>phenylalkyl which is substituted on the phenyl radical by C<SB>1</SB>-C<SB>4</SB>alkyl; or C<SB>1</SB>-C<SB>8</SB>acyl;<BR> and R<SB>5</SB> is hydrogen, C<SB>1</SB>-C<SB>12</SB>alkyl or C<SB>1</SB>-C<SB>12</SB>alkoxy;<BR> B) magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide or an organic salt of zinc or magnesium, or a hydrotalcite; and<BR> C) either<BR> <SL> <LI>(C1) an UV absorber or <LI>(C2) a pigment or <LI>(C3) an UV absorber and a pigment. </SL> Such a stabilizer mixture is particularly useful for stabilizing a polyolefin against light-induced degradation. Compound A) may also be a hindered amine of a specified formula (II), (IV), (V), (VI) or (VIII).

Description

Stabilizer mixtures This invention relates to a stabilizer mixture containing A) a certain sterically hindered amine compound, B) a magnesium compound or a zinc compound and C) an UV absorber and/or a pigment, the use of this stabilizer mixture for stabilizing a polyolefin against light-induced degradation and the polyolefin thus stabilized.

Several stabilizer mixtures have already been described in the prior art, for example in US-A-4 929 652, US-A-5 037 870, EP-A-290 388, EP-A-468 923 and EP-A-690 094.

Although numerous stabilizer systems already exist, there is still a need to improve the light stability of polyolefin furthermore.

This invention relates to a stabilizer mixture containing A) either (A1) at least one compound of the formula (I)

wherein the radicals R,, independently of one another, are hydrogen, C,-CBalkyl,-0-, -CH2CN, C3-C6alkenyl, C7-Cgphenylalkyl, C7-Cgphenylalkyl which is substituted on the phenyl radical by C,-C4alkyl ; or C,-C8acyl ; or (A2) at least one compound of the formula (ll)

wherein the radicals R2, independently of one another, have one of the definitions given for R1, and R3 is C2-C22alkylene, C5-C7cycloalkylene, C1-C4alkylenedi(C5-C7cycloalkylene), phenylene or phenylenedi (C,-C4alkylene) ; or (A3) at least one compound of the formula (III)

wherein the radicals R4, independently of one another, have one of the definitions given forR,, and Rs is hydrogen, C,-C, Zalkyl or C,-C, 2alkoxy ; or (A4) at least one compound of the formula (IV)

wherein the radicals R6, independently of one another, have one of the definitions given for R,, the radicals R7, independently of one another, are hydrogen or C,-C, 2alkyl, and R8 and R9, independently of one another, are C,-C, 2alkyl ; or (A5) at least one compound of the formula (V)

wherein the radicals R, o, independently of one another, have one of the definitions given for R1, and R"is C2-C22alkylene ; or (A6) at least one compound of the formula (VI)

wherein R, 2 is a group of the formula (VII)

in which R13 is C1-C12alkyl or C5-C12 cycloalkyl, R14 is C2-C12alkylene, and R, s has one of the meanings given for R, ; or (A7) at least one compound of the formula (VIII)

wherein R, 6 is C,-C24alkyi, and R17 has one of the definitions given for R, ; and B) magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide or an organic salt of zinc or magnesium, or a hydrotalcite ; and C) either (C1) an UV absorber or (C2) a pigment or (C3) an UV absorber and a pigment.

Component B) is preferably magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide or an organic salt of zinc or magnesium.

When component A) is at least one compound of the formula I or IV, component B) is preferably magnesium oxide, magnesium hydroxide or an organic salt of zinc or magnesium, in particular an organic salt of zinc or magnesium.

Examples of alkyl having up to 24 carbon atoms are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethyibutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3methylheptyl, n-octyl, 2-ethylhexyl, 1,1, 3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl and docosyl.

A preferred embodiment of R"R2, R4, R6, RXo, R1S and R17 is C,-C4alkyl, in particular methyl.

One of the preferred meanings of R5, R7, R8, Rg and R, 3 is C,-C8alkyl, in particular Cl-C4alkyl, for example methyl.

R16 is preferably C,-C, 4alkyl, in particular C8-C, 4alkyl, for example docecyl.

Examples of C,-C, 2aikoxy are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy and dodecyloxy.

One of the preferred meanings of R. is C,-C8aikoxy, in particular C-C4alkoxy, for example methoxy.

Examples of C5-C12cycloalkyl are cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclododecyl. Cs-C7cycloalkyl, in particular cyclohexyl, is preferred.

Examples of C3-C6alkenyl are allyi, 2-methallyl, butenyl, pentenyi and hexenyl. Allyf is preferred. The carbon atom in position 1 is preferably saturated.

C7-CgPhenylalkyl which is unsubstituted or substituted by C,-C4alkyl on the phenyl radical is, for example, benzyl, phenylethyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl or tert-butylbenzyl. Benzyl is preferred.

Ci-Cgacyt is preferably C1-C8alkanoyl, C3-C8alkenoyl or benzol. Examples are formyl, acetyl, propionyl, butyryl, pentanoyl, hexanoyl, octanoyl, benzoyl, acrylyl and crotonyl. Acetyl is preferred.

Examples of alkylene having up to 22 carbon atoms are ethylene, propylene, trimethylene, tetramethylene, pentamethylene, 2, 2-dimethyltrimethylene, hexamethylene, trimethylhexamethylene, octamethylene, decamethylene, undecamethylene, tetradecamethylene, hexadecamethylene and octadecamethylene. C2-C10alkylene is preferred, in particular C2-Csalkylene, for example dimethylene and hexamethylene.

R3 is preferably hexamethylene and R"and R, 4 are preferably dimethylene.

An example of C5-C7cycloalkylene is cyclohexylene.

An example of C1-C4alkylenedi(C5-C7cycloalkylene) is

An example of phenylenedi(C1-C4alkylene) is phenylenedimethylene.

The radical R. in the formula (III) is preferably in the para-position.

R R2, R4, R6, R10, R15 and R,,, independently of one another, are preferably hydrogen, C1-C4alkyl, allyl, benzyl or acetyl, in particular hydrogen or methyl.

The compounds described as component A) are essentially known (in some cases commercially available) and can be prepared by known processes, for example as described in US-A-4 769 457, US-A-4 976 889, GB-A-2 269 819, EP-A-172 413, US-A-4 190 571, US-A-5 071 981 and US-A-4 356 307.

Component A) is preferably #UVINUL 4049, #UVINUL 4050 H, #SANDUVOR PR-31, eSUMISORB TM 61, sGOODRITE UV 3034, eGOODRITE UV 3150, eGOODRITE UV 3159, #CYASORB UV 3581 or eSANDUVOR 3056.

A preferred embodiment of this invention relates to a stabilizer mixture wherein component A) is at least one compound of the formula (II), (ils), (V), (VI) or (VIII).

Preferred stabilizer mixtures are those wherein R3 is C2-C, oalkylene, cyclohexylene, (C,-C4alkylene) dicyclohexylene, phenylene or phenylenedi (C1-C4alkylene), R. is hydrogen, C1-C4alkyl or C,-C4alkoxy, the radicals R7, independently of one another, are hydrogen or C,-C4alkyl, R. and Rg, independently of one another, are C,-C4alkyl, R11 is C2-C10alkylene, R13 is C1-C4alkyl or cyclohexyl, R14 is C2-C10alkyleneand R16 is C1-C14 alkyl.

Particularly preferred stabilizer mixtures are those wherein component A) is a compound of the formula

The organic salt of zinc or magnesium defined in component B) is preferably a compound of the formula MeL2 in which Me is zinc or magnesium and L is an anion of an organic acid or of an enol. The organic acid can, for example, be a sulfonic acid, sulfinic acid, phosphonic acid or phosphinic acid, but is preferably a carboxylic acid. The acid can be aliphatic, aromatic, araliphatic or cycloaliphatic ; it can be linear or branched; it can be substituted by hydroxyl or alkoxy groups; it can be saturated or unsaturated and it preferably contains 1 to 24 carbon atoms.

Examples of carboxylic acids of this type are formic, acetic, propionic, butyric, isobutyric, caprioic, 2-ethylcaproic, caprylic, capric, lauric, palmitic, stearic, behenic, oleic, lactic, ricinoleic, 2-ethoxypropionic, benzoic, salicylic, 4-butylbenzoic, toluic, 4-dodecylbenzoic, phenylacetic, naphthylacetic, cyclohexanecarboxylic, 4-butylcyclohexanecarboxylic or cyclohexylacetic acid. The carboxylic acid can also be a technical mixture of carboxylic acids, for example technical mixtures of fatty acids or mixtures of alkylated benzoic acids.

Examples of organic acids containing sulfur or phosphorus are methanesulfonic, ethanesulfonic, a, dimethylethanesulfonic, n-butanesulfonic, n-dodecanesulfonic, benzenesulfonic, toluenesulfonic, 4-nonylbenzenesulfonic, 4-dodecylbenzenesulfonic or cyclohexanesulfonic acid, dodecanesulfinic, benzenesulfinic or naphthalenesulfinic acid, butylphosphonic acid, phenylphosphonic acid, monomethyl or monoethyl phenylphosphonate, monobutyl benzylphosphonate, dibutylphosphinic acid or diphenylphosphinic acid.

If L is an enolate anion, it is preferably an anion of a p-dicarbony ! compound or of an oacylphenol. Examples of p-dicarbony) compounds are acetylacetone, benzoylacetone, dibenzoylmethane, ethyl acetoacetate, butyl acetoacetate, lauryl acetoacetate or aacetylcyclohexanone. Examples of o-acylphenols are 2-acetylphenol, 2-butyroylphenol, 2 acetyf-1-naphthol, 2-benzoylphenol or salicylafdehyde. The enolate is preferably the anion of a p-dicarbony ! compound having 5 to 20 carbon atoms.

Preferred examples of component B) are magnesium acetate, laurate and stearate, zinc formate, acetate, oenanthate, laurate and stearate and zinc acetylacetonate and magnesium acetylacetonate.

In a preferred embodiment of this invention component B) as an organic salt of zinc or magnesium is preferably an acetylacetonate or an aliphatic monocarboxyiate having, for example, 1 to 24 carbon atoms.

A preferred hydrotalcite is Mg,., A12 (OH),,-C03-3. 5 H2O (&commat;DHT4A, 3Kyowa Chemical Industries Co. Ltd.).

The UV absorber in component C) is preferably a 2-(2'-hydroxyphenyl) benzotriazole, a 2hydroxybenzophenone, an ester of substituted or unsubstituted benzoic acid, an acrylate, an oxamide, a 2- (2-hydroxyphenyl)-1, 3,5-triazine, a monobenzoate of resorcinol or a formamidine.

The 2-(2'-hydroxyphenyl) benzotriazole is for example 2- (2'-hydroxy-5'-methylphenyl)-benzo- triazole, 2- (3', 5'-di-tert-butyl-2'-hydroxyphenyl) benzotriazole, 2- (5'-tert-butyl-2'-hydroxyphe- nyl) benzotriazole, 2- (2'-hydroxy-5'- (1, 1,3,3-tetramethylbutyl) phenyl) benzotriazole, 2- (3', 5'-di tert-butyl-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2- (3'-tert-butyl- 2'-hydroxy-5'-methyl- phenyl)-5-chloro-benzotriazole, 2- (3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-4'-octyloxyphenyl) benzotriazole, 2- (3', 5'-di-tert-amyl-2'-hydroxyphenyl) benzo triazole, 2- (3', 5'-bis- (a, a-dimethylbenzyl)-2'-hydroxyphenyl) benzotriazole, mixture of 2- (3' tert-butyl-2'-hydroxy-5'- (2-octyloxycarbonylethyl) phenyl)-5-chloro-benzotriazole, 2- (3'-tert- butyl-5'- [2- (2-ethylhexyloxy)-carbonylethyl]-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2- (3'- tert-butyl-2'-hydroxy-5'- (2-methoxycarbonylethyl) phenyl)-5-chloro-benzotriazole, 2- (3'-tert- butyl-2'-hydroxy-5'- (2-methoxycarbonylethyl) phenyl) benzotriazole, 2- (3'-tert-butyl-2'-hydroxy- 5'- (2-octyloxycarbonylethyl) phenyl) benzotriazole, 2- (3'-tert-butyl-5'- [2- (2-ethylhexyl- oxy) carbonylethyl]-2'-hydroxyphenyi) benzotriazole, 2- (3'-dodecyl-2'-hydroxy-5'-methylphe- nyl) benzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5'- (2-isooctyloxycarbonylethyl) phenylbenzotri- azole, 2,2'-methylene-bis [4- (1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol] or the transesterification product of 2- [3'-tert-butyl-5'- (2-methoxycarbonylethyl)-2'-hydroxyphenyl]- 2H-benzotriazole with polyethylene glycol 300;, where R = 3'-tert-butyl-4'-hydroxy-5'-2H-ben- zotriazol-2-ylphenyl.

2- (3', 5'-Di-tert-butyl-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5'- methylphenyl)-5-chloro-benzotriazole and 2- (3', 5'-di-tert-amyl-2'-hydroxyphenyl)- benzotriazole are preferred.

The 2-hydroxybenzophenone is for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyl- oxy, 4-dodecyloxy, 4-benzyloxy, 4,2', 4'-trihydroxy or 2'-hydroxy-4,4'-dimethoxy derivatives.

2-Hydroxy-4-octyloxybenzophenone is preferred.

The ester of a substituted or unsubstituted benzoic acid is for example 4-tert-butyl-phenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis (4-tert-butylbenzoyl) resorcinol, benzoyl resorcinol, 2,4-di-tertbutylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate or 2-methyi-4, 6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

2,4-Di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate and hexadecyl 3,5-di-tert-butyl-4hydroxybenzoate are preferred.

The acrylate is for example ethyl a-cyano- , -diphenylacrylate, isooctyl a-cyano- , -di- phenylacrylate, methyl a-carbomethoxycinnamate, methyl a-cyano- -methyl-p-methoxy- cinnamate, butyl a-cyano-p-methyl-p-methoxy-cinnamate, methyl a-carbomethoxy-p- methoxycinnamate or N- ( -carbomethoxy- -cyanovinyl)-2-methylindoline.

The oxamide is for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy5,5'-di-tert-butoxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butoxanilide, 2-ethoxy-2'-ethyloxanilide, N, N'-bis (3-dimethylaminopropyl) oxamide, 2-ethoxy-5-tert-butyl-2'-ethoxanilide or its mixture with 2-ethoxy-2'-ethyl-5, 4'-di-tert-butoxanilide or mixtures of ortho-and para-methoxy disubstituted oxanilides or mixtures of o-and p-ethoxy-disubstituted oxanilides.

The 2- (2-hydroxyphenyl)-1, 3,5-triazine is for example 2, 4,6-tris (2-hydroxy-4-octyloxyphenyl)-- 1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis (2, 4-dimethylphenyl)-1, 3,5-triazine, 2 (2,4-dihydroxyphenyl)-4,6-bis (2, 4-dimethylphenyl)-1, 3,5-triazine, 2,4-bis (2-hydroxy-4-propyl oxyphenyl)-6- (2, 4-dimethylphenyl)-1, 3,5-triazine, 2- (2-hydroxy-4-octyloxyphenyl)-4, 6-bis (4methylphenyl)-1, 3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4, 6-bis (2,4-dimethylphenyl)1,3,5-triazine, 2- (2-hydroxy-4-tridecyloxyphenyl)-4, 6-bis (2,4-dimethylphenyl)-1,3,5-triazine, 2 [2-hydroxy-4- (2-hydroxy-3-butyloxy-propoxy) phenyl]-4, 6-bis (2,4-dimethyl)-1,3,5-triazine, 2- [2- hydroxy-4- (2-hydroxy-3-octyloxy-propyioxy) phenyl]-4, 6-bis (2,4-dimethyl)-1,3,5-triazine, 2- [4- (dodecyloxyltridecyloxy-2-hydroxypropoxy)-2-hydroxy-phenyf]-4, 6-bis (2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy) phenyl]-4, 6-bis (2,4-dimethyl phenyl)-1, 3,5-triazine, 2- (2-hydroxy-4-hexyloxy) phenyl-4, 6-diphenyl-1, 3,5-triazine, 2- (2-hydroxy-4-methoxyphenyl)-4, 6-diphenyl-1, 3,5-triazine, 2,4,6-tris [2-hydroxy-4- (3-butoxy-2-- hydroxy-propoxy) phenyl]-1, 3,5-triazine or 2- (2-hydroxyphenyl)-4- (4-methoxyphenyl)-6-phe- nyl-1, 3,5-triazine.

2- (2-Hydroxy-4-octyloxyphenyl)-4, 6-bis (2,4-dimethylphenyl)-1,3,5-triazine and 2- (2-hydroxy4-hexyloxy) phenyl-4, 6-diphenyl-1, 3,5-triazine are preferred.

The monobenzoate of resorcinol is for example the compound of the formula

The formamidine is for example the compound of the formula

The UV absorber in component C) is in particular a 2- (2'-hydroxyphenyl) benzotriazole, a 2-hydroxybenzophenone or a 2- (2-hydroxyphenyl)-1, 3,5-triazine.

Component C) is preferably an UV absorber.

The pigment in component C) may be an inorganic or organic pigment.

Examples of inorganic pigments are titanium dioxide, zinc oxide, carbon black, cadmium sulfide, cadmium selenide, chromium oxide, iron oxide, lead oxide and so on.

Examples of organic pigments are azo pigments, anthraquinones, phthalocyanines, tetrachforoisoindo ! inones, quinacridones, isoindolines, perylenes, pyrrolopyrroles (such as Pigment Red 254) and so on.

As a pigment in component C), all pigments described in"Gachter/Muller : Plastics Additives Handbook, 3rd Edition, Hanser Publishers, Munich Vienna New York", page 647 to 659, point 11.2.1.1 to 11.2.4.2 can be used.

A particular preferred pigment is titanium dioxide.

A further preferred embodiment of this invention is a stabilizer mixture containing A) a compound of the formula (I-A), (Il-A), (III-A), (IV-A), (V-A), (VI-A), (VI-B), (VI ! I-A) or (VI II-B), B) magnesium stearate or zinc stearate and C) the compound

or TiO2 The stabilizer mixture according to the present invention is useful for stabilizing polyolefins.

Examples of suitable polyolefins are shown in the following.

1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene, 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), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), medium density polyethylene (MDPE), low density polyethy lene (LDPE), linear low density polyethylene (LLDPE), branched low density polyethylene (BLDPE).

Polyolefins, i. e. the polymers of monoolefins exemplified in the preceding paragraph, preferably polyethylene and polypropylene, can be prepared by different, and especially by the following, methods : a) radical polymerisation (normally under high pressure and at elevated temperature). b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups IVb, Vb, Vib or VIII of the Periodic Table. These metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either 7C-or :-coordinated. These metal complexes may be in the free form or fixed on substrates, typically on activated magnesium chloride, titanium (ill) chloride, aXumina or silicon oxide. These catalysts may be so ! uble or insoluble in the polymerisation medium. The catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of groups la, lla and/or Illa of the Periodic Table. The activators may be modified conveniently with further ester, ether, amine or silyl ether groups. These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).

2. Mixtures of the polymers mentioned under 1), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PPILDPE) 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, for example ethylene/propylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylenelbut-1-ene copolymers, propylene/isobutylene copolymers, ethylenelbut-1-ene copolymers, ethylenelhexene copo lymers, ethylenelmethylpentene copolymers, ethylenelheptene copolymers, ethylene/octene copolymers, propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethy lene/alkyl acrylate copolymers, ethylenelalkyl methacrylate copolymers, ethyfene/vinyl acetate copolymers and their copolymers with carbon monoxide or ethylene/acrylic acid copolymers and their salts (ionomers) as well as terpolymers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene-norbornene ; and mixtures of such copolymers with one another and with polymers mentioned in 1) above, for example polypropylenelethylene-propylene copolymers, LDPElethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbon monoxide copolymers and mixtures thereof with other polymers, for example polyamides.

The invention therefore furthermore relates to a composition containing a polyolefin and the novel stabilizer mixture.

The polyolefins listed above under point 1 are preferred. Polyethylene and polypropylene as well as a copolymer of polyethylene or polypropylene are particularly preferred.

The components of the novel stabilizer mixture can be added to the material to be stabilized either individually or mixed with one another. Component (A) is preferably present in an amount of 0.01 to 5 %, in particular 0.05 to 1 % ; component (B) is preferably present in an amount of 0.005 to 1 %, in particular 0.025 to 0.2 %; component (C1) is preferably present in an amount of 0.01 to 1 %, component (C2) is preferably present in an amount of 0.01 to 10 % and component (C3) is preferably present in an amount of 0.01 to 10 %."%"is % by weight, relative to the material to be stabilized.

The ratio of the UV absorber to the pigment in component (C3) is preferably 2: 1 to 1: 10.

The ratio of the components (A): (B) is preferably 30: 1 to 1: 30, for example 20: 1 to 1: 20 or 20: 1 to 1: 10.

The ratio of the components (A): (C,) is preferably 1: 20 to 30: 1, for example 1: 10 to 20: 1 or 1: 5 to 20: 1.

The ratio of the components (A): (C2) is preferably 1: 30 to 30: 1, for example 1 : 20 to 20: 1 or 1: 10 to 10: 1.

The ratio of the components (A) : (C3) is preferably 1: 30 to 30: 1, for example 1: 20 to 20: 1 or 1: 10 to 10: 1.

The novel stabilizer mixture or the individual components thereof can be incorporated into the polyolefin by known methods, for example before or during shaping or by applying the dissolved or dispersed compounds to the polyolefin, if necessary with subsequent evaporation of the solvent. The individual components of the novel stabilizer mixture can be added to the materials to be stabilized in the form of a powder, granules or a masterbatch, which contains these components in, for example, a concentration of from 2.5 to 25% by weight.

If desired, the components of the novel stabilizer mixture can be melt blended with each other before incorporation in the polyolefin.

The novel stabilizer mixture or its components can be added before or during the polymerization or before the crosslinking.

The materials stabilized in this way can be used in a wide variety of forms, for example as films, fibres, tapes, moulding compositions, profiles or as binders for paints, adhesives or putties.

The stabilized polyolefin of the invention may additionally also contain various conventional additives, for example: 1. Antioxidants 1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert butyl-4, 6-dimethylphenol, 2,6-di-tert-butyl4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2- (a methylcyclohexyl)-4, 6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenols which are linear or branched in the side chains, for example, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6- (1'-methylundec-1'-yl) phenol, 2,4-dimethyl-6- (1'-methyl heptadec-1'-yl) phenol, 2,4-dimethyl-6- (1'-methyitridec-1'-yl) phenol and mixtures thereof.

1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-didodecylthiomethyl-4-nonylphenol.

1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4 hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis- (3, 5-di-tert-buty !-4-hydroxyphenyl) adipate.

1.4. Tocopherols, for example c-tocopherol, ss-tocopherol, y-tocopherol, 6- tocopherol and mixtures thereof (Vitamin E).

1.5. 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-methylphenoi), 4,4'-thiobis (6-tert-butyl-2-methylphenol), 4,4'-thiobis- (3, 6-di-sec-amylphenol), 4,4' bis- (2, 6-dimethyl-4-hydroxyphenyl) disulfide.

1.6. Alkylidenebisphenols, for example 2, 2'-methylenebis (6-tert-butyl-4 methyiphenoI), 2,2'-methylenebis (6-tert-butyl-4-ethylphenol), 2,2'-methylenebis [4methyl-6- (a-methylcyclohexyl) phenol], 2,2'-methylenebis (4-methyl-6-cyclohexylphenol), 2,2'-methylenebis (6-nonyl-4-methylphenol), 2,2'-methylenebis (4,6-di-tertbutylphenol), 2,2'-ethylidenebis (4,6-di-tert-butylphenol), 2,2'-ethylidenebis (6-tertbutyl-4-isobutylphenol), 2,2'-methylenebis [6-(a-methylbenzyl)-4-nonyiphenol], 2,2' methylenebis [6- (a, a-dimethylbenzyl)-4-nonylphenol], 4, 4'-methylenebis (2,6-di-tertbutylphenol), 4,4'-methylenebis (6-tert-butyl-2-methylphenol), 1,1-bis (5-tert-butyl-4hydroxy-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-5methyl-phenyl) dicyclopentadiene, bis [2- (3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6- tert-butyl-4-methylphenyl] terephthalate, 1,1-bis- (3, 5-dimethyl-2-hydroxyphenyl) butane, 2,2-bis- (3, 5-di-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis- (5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetra- (5-tert- butyl-4-hydroxy2-methylphenyl) pentane.

1.7. O-, N-and S-benzyl compounds, for example 3,5,3', 5'-tetra-tert-butyl-4, 4' dihydroxydibenzyl ether, octadecyl-4-hydroxy-3, 5-dimethylbenzylmercaptoacetate, tridecyl-4-hydroxy-3, 5-di-tert-butylbenzylmercaptoacetate, tris (3,5-di-tert-butyl-4hydroxybenzyl) amine, bis (4-tert-butyl-3-hydroxy-2, 6-dimethylbenzyl) dithiotereph thalate, bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl-3, 5di-tert-buy-4 hydroxybenzylmercaptoacetate.

1.8. Hydroxybenzylåted malonates, for example dioctadecyl-2, 2-bis- (3, 5-di-tert- butyl-2-hydroxybenzyl)-mafonate, di-octadecyl-2- (3-tert-butyl-4-hydroxy-5-- methylbenzyl)-malonate, di-dodecylmercaptoethyl-2, 2-bis- (3, 5-di-tert-butyl-4- hydroxybenzyl) malonate, bis [4- (1, 1,3,3-tetramethylbutyl) phenyl]-2,2-bis (3,5-di-tert butyl-4-hydroxybenzyl) malonate.

1.9. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris- (3, 5-di-tert-butyl-4hydroxybenzyl)-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) pheno).

1.10. Triazine Compound 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-4hydroxyphenoxy)-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-butyi-4-hydroxybenzyl) isocyanurate, 1,3,5tris (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-4hydroxybenzyl) isocyanurate.

1.11. 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-hydroxy3- methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tertbutyl-4-hydroxybenzylphosphonic acid.

1.12. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N- (3, 5-di-tert-butyl-4-hydroxyphenyl) carbamate.

1.13. Esters of- (3, 5-di-tert-buty)-4-hydroxypheny)) propionicadd with mono-or polyhydric alcohols, e. g. with methanoi, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene giycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-lphospha-2,6,7-trioxabicyclo [2.2.2] octane.

1.14. Esters of 2-(5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid with monoor polyhydric alcohols, e. g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethy !) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4 hydroxymethyl-1-phospha-2, 6,7-trioxabicyclo [2.2.2] octane.

1.15. Esters of-(3, 5-dicyclohexyl4-hydroxyphenyl) propionic acid with mono-or polyhydric alcohols, e. g. with methanol, ethanol, octanol, octadecanol, 1,6hexanediol, 1, 9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3 thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1- phospha-2,6,7-trioxabicyclo [2.2.2octane.

1.16. Esters of 3,5-di-tert-butyl4-hydroxyphenyl acetic acid with mono-or polyhydric alcohols, e. g. with methanol, ethanol, octanol, octadecanol, 1,6 hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethyiene giycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1- phospha-2, 6,7-trioxabicyclo [2.2.2] octane.

1.17. Amides of ss-(3, 5-di-tert-butyi-4-hydroxyphenyl) propionic acid e. g. N, N'bis (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hexamethylenediamine, N, N'bis (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) trimethylenediamine, N, N'-bis (3,5-di tert-butyl-4-hydroxyphenyipropionyl) hydrazine.

1.18. Ascorbic acid (vitamin C) 1.19. Aminic antioxidants, for example N, N'-di-isopropyl-p-phenylenediamine, N, N'di-sec-butyl-p-phenylenediamine, N, N'-bis (1, 4-dimethylpentyl)-p phenylenediamine, N, N'-bis (1-ethyl-3-methylpentyl)-p-phenylenediamine, N, N'bis (1-methylheptyl)-p-phenylenediamine, N, N'-dicyclohexyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-bis (2-naphthyl)-p-phenylenediamine, N isopropyl-N'-phenyl-p-phenylenediamine, N- (1, 3-dimethylbutyl)-N'-pheny !-p-- phenylenediamine, N- (1-methylheptyl)-N'-phenyl-p-phenylenediamine, N cyclohexyl-N'-phenyl-p-phenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N, N'-dimethyl-N, N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphe- nylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N- (4-tert-- octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated di phenylamine, for example p, p'-di-tert-octyidiphenylamine, 4-n-butylaminophenol, 4butyrylaminophenol, 4-nonanoylamino-phenol, 4-dodecanoylaminophenol, 4-octa decanoylaminophenol, bis (4-methoxyphenyl) amine, 2,6-di-tert-butyl4-dimethyi aminomethylphenol, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, N, N, N', N'-tetramethyl-4, 4'-diaminodiphenylmethane, 1,2-bis [ (2- methylphenyl) amino] ethane, 1,2-bis (phenylamino) propane, (o-tolyl) biguanide, Bis [4- (1', 3'-dimethylbutyl) phenyl] amine, tert-octylated N-phenyl-1-naphthylamine, a mixture of mono-and dialkylated tert-butyl/tert-octyldiphenylamines, a mixture of mono-and dialkylated nonyidiphenylamines, a mixture of mono-and dialkylated dodecyidiphenylamines, a mixture of mono-and dialkylated isopropyl/isohexyldi- phenylamines, a mixture of mono-und dialkylated tert-butyidiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, a mixture of mono-und dialkylated tert-butyl/tert-octylphenothiazines, a mixture of mono-und dialkylated tert-octyl-phenothiazines, N-allylphenothiazin, N, N, N', N'-tetraphenyl.-1, 4-diaminobut-2-ene, N, N-bis (2,2,6,6-tetramethyl-piperid4-yl-hexamethylenediamine, bis (2,2,6,6-tetramethylpiperid-4-yl) sebacate, 2,2,6,6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.

2. UV absorbers and light stabilisers 2.1 Nickel compound, 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 the monoalkyl esters, e. g. the methyl or ethyi ester, of 4-hydroxy-3, 5-di-tert-butylbenzylphosphonic acid, nickel complexes of ketoximes, e. g. of 2-hydroxy-4-methylphenyl undecylketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands.

2.2 Sterically hindered amines, for example bis (2,2,6,6-tetramethyl-4piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (1,2,2,6,6 pentamethyi-4-piperidyl) sebacate, bis (1-octyloxy-2, 2,6,6-tetramethyl-4 piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3, 5-di-tert-butyl4-hydroxybenzylmalonate, the condensate of 1- (2-hydroxyethyl)-2, 2,6,6 tetramethyl-4-hydroxypiperidine and succinic acid, the condensate of N, N'bis(2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 4-tert-octylamino2, 6-dichloro-1, 3,5-triazine, tris (2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate, tetrakis (2. 2,6,6-tetra methyl-4-pi peridyl)-1 2,3,4-butane-tetracarboxylate, 4benzol-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-triazaspiro [4.5] decan-2, 4dion, bis (1-octyloxy-2, 2,6,6-tetramethylpiperidyl) sebacate, bis (1-octyloxy-2, 2,6,6- tetramethylpiperidyl) succinate, the condensate of N, N'-bis- (2, 2,6,6-tetramethyl-4piperidyl) hexamethylenediamine and 4-morpholino-2, 6-dichloro-1, 3,5-triazine, the condensate of 2-chloro-4, 6-bis (4-n-butylamino-2, 2,6,6-tetramethylpiperidyl)-1,3,5triazine and 1,2-bis (3-aminopropylamino) ethane, the condensate 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- triazaspiro [4.5] decane-2,4-dione, 3-dodecyl-1-(2, 2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2, 5-dione, 3-dodecy !-1- (1, 2,2,6,6-pentamethyl-4-piperidyl) pyrrolidine-2,5dione, a mixture of 4-hexadecyloxy-and 4-stearyloxy-2, 2,6,6-tetramethylpiperidine, a condensation product of N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethy lenediamine and 4-cyclohexylamino-2, 6-dichloro-1, 3,5-triazine, a condensation product of 1,2-bis (3-aminopropylamino) ethane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylamino-2, 2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-61) ; N- (2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimid, N- (1,2,2,6,6-pentamethyl4-piperidyl)-n-dodecylsuccinimid, 2-undecyl-7, 7,9,9-tetramethyl-1-oxa-3,8-diaza-4oxo-spiro [4,5] decane, a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1oxa-3,8-diaza-4-oxospiro [4,5] decane und epichlorohydrin.

3. Metal deactivators, for example N, N'-diphenyloxamide, N-salicylal-N'-salicyloyl hydrazine, N, N'-bis (salicyloyl) hydrazine, N, N'-bis (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hydrazine, 3-salicyloylamino-1, 2,4-triazole, bis (benzylidene) oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N, N'-diacetyladipoyl dihydrazide, N, N'-bis (salicyloyl) oxalyl dihydrazide, N, N'-bis (salicyloyl) thiopropionyl dihydrazide.

4. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyt dialkyl phosphites, tris (nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris (2,4-ditert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis (2,4-di-tertbutylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, diisodecyloxypentaerythritol diphosphite, bis (2,4-ditert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tris (tertbutylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis (2,4di-tert-butylphenyl) 4,4'-biphenylene diphosphonite, 6-isooctyloxy-2, 4,8,10-tetratert-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, bis (2,4-di-tert-butyl-6-methylphenyl) methylphosphite, bis (2,4-di-tert-butyl-6-methylphenyl) ethylphosphite.

5. Hydroxylamines, for example, N, N-dibenzylhydroxylamine, N, N-diethylhydroxyi- amine, N, N-dioctylhydroxylamine, N, N-dilaurylhydroxylamine, N, N-ditetradecylhy- droxylamine, N, N-dihexadecylhydroxylamine, N, N-dioctadecylhydroxylamine, N hexadecyl-N-octadecylhydroxylamine, N-heptadecyi-N-octadecylhydroxylamine, N, N-dialkyihydroxyiamine derived from hydrogenated taliow amine.

6. Nitrones, for example, N-benzyi-alpha-phenyl-nitrone, N-ethyl-alpha-methyl- nitrone, N-octyl-alpha-heptyl-nitrone, N-lauryl-alpha-undecyl-nitrone, N-tetradecyl-- alpha-tridecyl-nitrone, N-hexadecyl-alpha-pentadecyl-nitrone, N-octadecyl-alpha- heptadecyl-nitrone, N-hexadecyl-alpha-heptadecyl-nitrone, N-ocatadecyl-alpha pentadecyi-nitrone, N-heptadecyl-alpha-heptadecyl-nitrone, N-octadecyl-alpha hexadecyl-nitrone, nitrone derived from N, N-dialkylhydroxylamine derived from hydrogenated tallow amine.

7. Thiosynergists, for example, dilauryl thiodipropionate or distearyl thiodipropionate.

8. Peroxide scavengers, for example esters of -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 (p-dodecy) mercapto) propionate.

9. Basic co-stabilisers, for example, meiamine, 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 calcium stearate, zinc stearate, magnesium behenate, magnesium stea, ate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate or tin pyrocatecholate.

10. Nucleating agents, for exarnple, inorganic substances such as talcum, metal oxides such as titanium dioxide or magnesium oxide, phosphates, carbonates or sulfates of, preferably, alkaiine earth mettais ; organic compounds such as mono-or polycarboxylic acids and the salts thereof, e. g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodium succinate or sodium benzoate; polymeric compounds such as ionic copolymers ("ionomers").

11. Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass fibres, glass bulbs, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite, wood flour and flours or fibers of other natural products, synthetic fibers.

12. Other additives, for example, plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, optical brighteners, flameproofing agents, antistatic agents and blowing agents.

13. Benzofuranones and indolinones, for example those disclosed in US-A4325863, US-A-4338244, US-A-5175312, US-A-5216052, US-A-5252643, DE-A4316611, DE-A-4316622, DE-A-4316876, EP-A-0589839 or EP-A-0591102 or 3- [4- (2-acetoxyethoxy) phenyl]-5, 7-di-tert-butyl-benzofuran-2-one, 5,7-di-tert-butyl-3 [4-(2-stearoyioxyethoxy) phenyl] benzofuran-2-one, 3,3'-bis [5,7-di-tert-butyl-3- (4- [2hydroxyethoxy] phenyl) benzofuran-2-one], 5,7-di-tert-butyl-3- (4-ethoxyphenyl) benzofuran-2-one, 3- (4-acetoxy-3, 5-dimethylphenyl)-5, 7-di-tert-butyl-benzofuran-2-- one, 3- (3, 5-dimethyl-4-pivaloyloxyphenyl)-5, 7-di-tert-butyl-benzofuran-2-one.

The weight ratio of the total amount of components A), B) and C) to the conventional additives can be, for example, from 1: 0.1 to 1: 5.

The invention furthermore relates to the use of the novel stabilizer mixture for stabilizing a polyolefin against light-induced degradation.

The examples below illustrate the invention in greater detail. All percentages and parts are by weight, unless stated otherwise. Stabilizers used in Examples 1 and 2: Compound (I-A):

Compound (Il-A) :

Compound (III-A):

Compound:

Compound (VI-A) :

Compound (VI-B) :

Compound (VIII-A) :

Compound (VIII-B) :

Compound (XX):

The mean value of n is 5.1.

Compound (C):

Example 1: Light stabilization in polypropylene homopolymer films.

100 parts of polypropylene homopolymer powder are homogenized with 0.05 part of pentaerythrityl tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate], 0.05 part of tris (2,4-di-tert-butylphenyl) phosphite and with the stabilizers indicated in Tables 1 and 2 in a Brabender plastograph at 200 C for 10 minutes. The composition thus obtained is removed from the compounder as rapidly as possible and compressed in a toggle press to give a sheet with a thickness of 2-3 mm. A piece of the resultant press-molding ; cut out and pressed between two high-gloss hard aluminium foils for 6 minutes at 260 C using a laboratory hydraulic press to give a film with a thickness of 0.5 mm, which is immediately cooled in a water-cooled press. Sections each measuring 60 mm x 25 mm are then punched out of this 0.5 mm film and are exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63+2 C, without water-spraying). These test specimens are removed from the exposure apparatus at regular intervals and tested for their carbonyl content in an IR spectrometer. The increase in the carbonyl extinction on exposure is a measure of the photooxidative degradation of the polymer and is known from experience to be associated with a deterioration in the mechanical properties.

The time (To 1 measured) needed to reach a carbonyl extinction of 0.1 is shown in Tables 1 and 2.

Table 1 : Light stabilization action in polypropylene homopolymer films.

Light stabilizer To., measured in hours 0.05 % of (I-A), 0.1 % of magnesium stearate and 0.1 % of (C) 1830 0.05 % of (II-A), 0.1 % of magnesium stearate and 0.1 % of (C) 1690 0.05 % of (III-A), 0.1 % of magnesium stearate and 0.1 % of (C) 1840 0.05 % of (V-A), 0.1 % of magnesium stearate and 0.1 % of (C) 2880 0.05 % of (VI-A), 0.1 % of magnesium stearate and 0.1 % of (C) 2060 0.05 % of (VI-B), 0.1 % of magnesium stearate and 0.1 % of (C) 2180 0.05 % of (VIII-A), 0.1 % of magnesium stearate and 0.1 % of (C) 2700 0.05 % of (VIII-B), 0. 1 % of magnesium stearate and 0.1 % of (C) 2320 Comparison: Stabilizer mixture according to US-A-4 929 652 0.05 % of (XX), 0.1 % of rnagnesium stearate and 0.1 % of (C) 1620 Table 2: Light stabilization action in polypropylene homopolymer films.

Light stabilizer T0.1 measured in hours 0.05 % of (I-A), 0.1 % of zinc stearate and 0.5 % of Ti02 (rutile) 1840 0.05 % of (II-A), 0.1 % of zinc stearate and 0.5 % of TiO2 (rutile) 1740 0.05 % of (III-A), 0. 1 % of zinc stearate and 0.5 % of TiO2 (rutile) 1720 0.05 % of (V-A), 0.1 % of zinc stearate and 0.5 % of TiO2 (rutile) 3140 0.05 % of (VI-A), 0.1 % of zinc stearate and 0.5 % of TiO2 (rutile) 1940 0.05 % of (VI-B), 0.1 % of zinc stearate and 0.5 % of TiO2 (rutile) 1710 0.05 % of (VIII-A), 0.1 % of zinc stearate and 0.5 % of TiOz (rutile) 2700 0.05 % of (VIII-B), 0.1 % of zinc stearate and 0.5 % of TiO2 (rutile) 2560 Comparison: Stabilizer mixture according to US-A-4 929 652 0.05 % of (XX), 0.1 % of zinc stearate and 0.5 % of TiO2 (rutile) 1230 Example 2: Light stabilization in polypropylene block copolymer films.

100 parts of polypropylene block copolymer powder are homogenized with 0.05 part of pe taerythrityl tetrakist3-(3, 5-di-tert-butyl4-hydroxyphenyl) propionate], 0.10 part of tris (2,4-di-tert-butylphenyl) phosphite and with the stabilizer mixture indicated in Table 3 in a Brabender plastograph at 200 C for 10 minutes. The composition thus obtained is removed from the compounder as rapidly as possible and compressed in a toggle press to give a sheet with a thickness of 2-3 mm. A piece of the resultant press-moulding is cut out and pressed between two high-gloss hard aluminium foils for 6 minutes at 260 C using a laboratory hydraulic press to give a film with a thickness of 0.5 mm, which is immediately cooled in a water-cooled press. Sections each measuring 60 mm x 25 mm are then punched out of this 0.5 mm film and are exposed in a WEATHER-OMETER Ci 65 (black panel temperature 63+2 C, without water-spraying). These test specimens are removed from the exposure apparatus at regular intervals and tested for their carbonyl content in an IR spectrometer. The increase in the carbonyl extinction on exposure is a measure of the photooxidative degradation of the polymer and is known from experience to be associated with a deterioration in the mechanical properties.

The time (To. 1 measured) needed to reach a carbonyl extinction of 0.1 is shown in Table 3.

Table 3 : Stabilizer mixture T0.1 measured in hours 0.05 % of (Il-A), 0.1 % of magnesium stearate and 0.1 % of (C) 4720 0.05 % of (Vlll-A), 0.1 % of magnesium stearate and 0.1 % of (C) 6760 0.05 % of (VIII-B), 0.1 % of magnesium stearate and 0.1 % of (C) 5840 Comparison: Stabilizer mixture according to US-A-4 929 652 0.05 % of (XX), 0.1 % of magnesium stearate and 0.1 % of (C) 4400

Claims (16)

1. Claims : 1. A stabilizer mixture containing A) either at least one compound of the formula (III)

   wherein the radicals R4, independently of one another, are hydrogen, C1-C8alkyl, -O; -CH2CN, C3-C6alkenyl, C7-C9phenylalkyl, C7-C9phenylalkyi which is substituted on the phenyl radical by C,-C4alkyl ; or C,-C8acyl ; and Rs is hydrogen, C,-C, 2alkyl or C,-C, 2alkoxy ; or at least one compound of the formula (II)

   wherein the radicals R2, independently of one another, have one of the definitions given for R4, and R3 is C2-C22alkylene, C5-C7cycloalkylene, C1-C4alkylened(C5-C7cycloalkylene), phenylene or phenylenedi (C,-C4alkyiene) ; or at least one compound of the formula (IV)

   wherein the radicals R6, independently of one another, have one of the definitions given for R4, the radicals R7, independently of one another, are hydrogen or C,-C, 2alkyl, and R8 and Rg, independently of one another, are C1-C12alkyl ; or at least one compound of the formula (V)

   wherein the radicals R, o, independently of one another, have one of the definitions given for R4, and R"is C2-C22alkylene ; or at least one compound of the formula (Vf)

   wherein R, 2 is a group of the formula (VII)

   in which R13 is C1-C12alkyl or C5-C12cycloalkyl, R14 is C2-C12alkylene, and R, s has one of the meanings given for R4 ; or at least one compound of the formuia (Vlil)

   wherein R,, is Cl-C24alkyl, and R17 has one of the definitions given for R4 ; and B) magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide or an organic salt of zinc or magnesium, or a hydrotalcite ; and C) either (C1) an UV absorber or (C2) a pigment or (C3) an UV absorber and a pigment.
2. 2. A stabilizer mixture according to claim 1 wherein component B) is magnesium oxide, magnesium hydroxide, zinc oxide, zinc hydroxide or an organic salt of zinc or magnesium.
3. 3. A stabilizer mixture according to claim 1 wherein component A) is a compound of the formula (III), (II), (V), (VI) or (Vlil).
4. 4. A stabilizer mixture according to claim 1 wherein the radicals R2, R4, R6, Rro, R, 5 and R", independently of one another, are hydrogen, C,-C4alkyl, allyl, benzyi or acetyl.
5. 5. A stabilizer mixture according to claim 1 wherein the radicals R2, R4, R6, R10, R15 and R, 7, independently of one another, are hydrogen or methyl.
6. 6. A stabilizer mixture according to claim 1 wherein R3 is C2-C10alkylene, cyclohexylene, (C1-C4alkylene)dicyclohexylene, phenylene or phenylenedi (C,-C4alkylene), R. is hydrogen, C,-C4alkyl or C1-C4alkoxy, the radicals R7, independently of one another, are hydrogen or C,-C4alkyl, R, and R9, independently of one another, are C1-C4alkyl, R11 is C2-C10alkylene, R13 is C1-C4alkyl or cyclohexyl, R14 is C2-C10alkyleneand R16 is C1-C14alkyl.
7. 7. A stabilizer mixture according to claim 1 wherein component A) is a compound of the formula
8. 8. A stabilizer mixture according to claim 1 wherein the organic salt of zinc or magnesium is an acetylacetonate or an aliphatic monocarboxyiate.
9. 9. A stabilizer mixture according to claim 1 wherein the UV absorber is a 2- (2'- hydroxyphenyl) benzotriazole, a 2-hydroxybenzophenone, an ester of substituted or unsubstituted benzoic acid, an acrylate, an oxamide, a 2- (2-hydroxyphenyl)- 1,3,5-triazine, a monobenzoate of resorcinol or a formamidine.
10. 10. A stabilizer mixture according to claim 1 wherein the UV absorber is a 2- (2'-hydroxyphenyl) benzotriazole, a 2-hydroxybenzophenone or a 2- (2-hydroxyphenyl)-1, 3,5-triazine.
11. 11. A stabilizer mixture according to claim 1 wherein the pigment is titanium dioxide.
12. 12. A stabilizer mixture according to claim 1, containing as component C) an UV absorber
13. 13. A stabilizer mixture according to claim 7 wherein component B) is magnesium stearate or zinc stearate and component C) is the compound

    or TiO2
14. 14. A composition containing a polyolefin and a stabilizer mixture according to claim 1.
15. 15. A composition according to claim 14 wherein the po ! yo) efin is polyethylene or polypropylene or a copolymer of polyethylene or polypropylene.
16. 16. A method for stabilizing a polyolefin against light-induced degradation, which comprises adding to the polyolefin a stabilizer mixture according to claim 1.