GB2311526A - Polyolefins containing catalyst residues and stabilised with trialkanolamine triphosphites - Google Patents

Description

A-20804/AICGC 1852 2311526 Polvolefins containing catalyst residues

stabilized with trialkanolamine trisphosphites The instant invention pertains to polyolefins containing catalyst residues which are stabilized by the use of trialkanolamine trisphosphites.

From around 1930 to 1950, polyethylene was produced by a liquid phase high pressure free radical process [R. V. Raff and J. B. Allison, Polyethylene, Interscience, New York (1956)]. During the 1950's, it was discovered that ethylene could be polymerized using transition metal complexes as homogeneous or heterogeneous catalysts. This led to several types of polyethylene homopolymer [K. Ziegler et al. Angew. Chem., 67, 541 (1955); J. P. Hogan et al., Belgian Patent No. 530,617 (January 24, 1955); D. James, Encyclopedia of Polymer Science and Engineering, 1 st Ed. , Wiley Interscience, New York, Vol. 6, 1986, p 429; and D. L. Beach et al., ibid. page 4541. Stereoregular polypropylene was discovered soon thereafter [G. Natta et al., J. Am. Chem. Soc., 37 1708 (1955); R. B. Lieberman, Encyclopedia of Polymer Science and Engineering, 1 st Ed, Wiley-iInterscience, New York, Vol. 13, 1986, p 429; and P. Pino et al. Angew. Chem. Int. Ed. Engl., 19, 857 (1980)1.

Over the last forty years, the area of polymerization research and technology has undergone numberous revolutionary steps forward [P. Locatelli, Trends in Poly. Sci., 3. 87 (1994)]. Today, there are a multitude of differents types of polyolefin homopolymers and copolymers. There are a variety of processes for polymerization, based on liquid, slurry, bulk and gas phase reactor designs [D. James, loc cit; D. L. Beach et al., loc cit; R. B. Lieberman, loc: cit; and P. Pino et al., loc cit]. There are also a wide range of transition metal-based catalyst families for the olefin polymerization reaction, such a titanium, vanadium, chromium and zirconium. There are also various cocatalysts based on alkylaluminurn chemistry. Catalyst supports, stereospecificity control agents and promoters are key reagents used to improve rates and the stereo regularity obtainable in the polymerization reaction [M. Farina, Trends in Poly. Sci., 3, 80 (1994)].

Perhaps one of the most intriguing developments in olefin polymerization catalysis is the advent of single site catalysis utilizing metallocene chemistry [W. Karninsky, Catal. Today, 20, 257 (1994)]. This relatively new field of polymerization chemistry is primarily based on early transition metal catalysts, such as titanium and zirconium, with cocatalysts based on aluminum alkyls, aluminoxanes or anionic noncoordinating boron reagents [A. D. Horton, Trend in Poly. Sci., 2, 158 (1994)].

In the early days of transition metal catalyzed olefin polymerization chemistry, significant effort was made to deactivate the catalyst residues [D. James, loc cit; and R. B. Lieberman, loc cit]. Catalyst removal or deactivation was considered necessary because the catalyst residue levels were high and their impact was found to be quite deleterious to the ultimate stability of the polymer.

In the past, one approach to catalyst deactivation was to treat the polymer reaction mass with alkaline water or alcohol solutions followed by a vigorous washing step to remove the solubilized deactivated catalyst. Another approach, in solution phase processes, was to remove the polymerization catalysts by treating the molten polymer with chelating reagents to deactivate and precipitate the catalyst, following by a filtering or adsorption step to remove the transformed catalyst components. Although these approaches proved to be time consuming and energy intensive, the resultant "purified" polymers were significantly easier to stabilize with conventional antioxidants after the removal of the detrimental impurities, namely the catalyst residues. The high demand for both polyethylene and polypropylene allowed for the costs associated with removing such residues to be incorporated into the price of the final products.

Currently in many cases, catalyst residues receive little or no deactivating/removal treatments and are left in the polymer. This puts an added burden on any stabilizers used in such polymers containing catalyst residues to provide adequate and satisfactory stabilization efficacy.

United States Patent No. 5,488,079 teaches that polyolefin compositions produced in the presence of a Ziegler or metallocene type catalyst from whirh the catalyst has not been removed from the polyolefin can be stabilized by the addition of a substituted phosphine such as tris(2,4-ditert-butylphenyl)phosphine.

United States Patent No. 5,238,979 and European Patent Application 393, 030 disclose the use of cyclic monophosphites for use in polyolefin resins containing Ziegler-type complex catalyst residues. The instant invention describes the use of trialkanolamine trisphophites which are structurally very different from the prior art compounds of U.S. 5,238, 979.

The tfialkanolamine trisphosphites useful for stabilizing the polyolefins are described in United States Patent Nos. 5,276,076; 5,326,802; 5,331,03 1; 5,334,739; 5,344,860; 5,373,040; 5,405,893; 5,489,635 or 5,489,636.

The instant invention pertains to polyolefin compositions which contain catalyst residues and which are stabilized against oxidative, thermal and/or light-induced degradation by an effective stabilizing amount of a trialkanolamine trisphosphite.

More particularly, the instant invention relates to a composition comprising a) a polyolefin subject to oxidative, thermal andlor lightinduced degradation comprising at least one transition-metal or maingroup metal or mixture thereof residue in an amount of 10 to 1000 ppm as a result of said metal being used as a catalyst or cocatalyst to effect polymerization of said polyolefin, and b) an effective stabilizing amount of a compound of the formula I Z1 Z2 Y1 (Q) Y2 4- 0 p ---- 0 1 U 1 M3 Y5 A1 A2,,__ Y3 Z6 n (Q)n Z3 0 0 Z5 Y6 Y4 Z4 wherein n is 0 or 1, when n is 0, Q is a direct bond, or when n is 1, Q is -S- or -CRIR2- wherein R, and R2 are independently hydrogen, straight or branched chain alkyl of 1 to 18 carbon atoms, phenyl, tolyl or anisyl, YP Y2, Y3, Y4, Y5, Y6, ZI, Z2, Z3, Z4, Z5 and Z6 are independently hydrogen, a straight or branched chain alkyl of 1 to 18 carbon atoms, bicyloalkyl of 7 to 10 carbon atoms, phenyl, benzyl, 1 -phenethyl, cyclohexyl, 1 - methyleyclohexyl, cyano, halogen, nitro, trifluoromethyl, hydroxy, amino, alkanoyl of 2 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms or E1EAS' where Ep E2and E3 are independently hydrogen, alkyl of 1 to 4 carbon atoms or phenyl, and A,, A2 and A3 are independently straight or branched alkylene of 1 to 18 carbon atoms, cycloalkylene of 5 to 6 carbon atoms or a branched chain alkylene of 1 to 8 carbon atoms with a stereocenter.

When any of R, or R2, Y1 to Y6, ZI to Z6 and A, to A3 are straight or branched chain alkyl of 1 to 18 carbon atoms, such alkyl groups are, for example, methyl, ethyl, isopropyl, n-butyl, isobutyl, tert-butyl, tertamyl, 2-ethylhexyl, n-oetyl, tert-octyl, lauryl, n-octadecyl, elcosyl and triacontyl; when said radicals are bicycloalkyl of 7 to 10 carbon atoms, they are, for example, isobornyl or adamantyl; when said radicals are halogen, they are, for example, fluorine, chlorine or bromo; when said radicals are alkanoyl of 2 to 18 carbon atoms, they are, for example, acetyl, propionyl, butyryl or decanoyl; when said radicals are alkoxy of 1 to 18 carbon atomm, they are, for example, methoxy, ethoxy, propoxy, nbutoxy, n-pentoxy, hexyloxy, heptyloxy or decyloxy.

When A, to A3 are cycloalkylene of 5 to 6 carbon atoms, they are, for example, 1,2- cyclopentylene, 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3eyclohexylene or 1,4-cyclohexylene; when sain radicals are straight or branched alkylene of 1 to 18 carbon atoms, they are, for example, methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene or dodecylene.

Preference is given to compositions in which in component (b) n is 0 or 1, Z> when n is 0, Q is a direct bond, or when n is 1, Q is methylene or ethylidene, Y1, Y2, Y3, Y4, YS, Y6, ZI, Z2, Z3, Z4, Z5 and Z6 are each tert-butyl, and Ap A2 and A3 are each ethylene or 2-propylene where the secondary carbon is attached to the oxygen atom.

Of specific interest is a composition in which in component (b) n is 0, Q is a direct bond, Y1, Y2, Y3, Y4, YS, Y6, Z1, Z2, Z3, Z4, Z5 and Z6 are each tert-butyl, and A,, A2 and A3 are each ethylene.

Ziegler-type complex catalysts supported on a halogen-containing magnesium compound can give yields of polymer (per given amount of a transition metal, e.g. titanium, which is the main component of the catalyst) that range from several hundred times to thousands of times as much as the yield obtained when an unsupported catalyst is used (such a catalyst system comprises diethylaluminum monochloride and an activated titanium trichloridealuminum chloride mixture which has been prepared by reducing titanium tetrachloride with metallic aluminum and milling the reaction product). Such catalyst systems results in catalyst residues which are removed from the resulting polyolefin resins as described earlier. While such supported catalysts provide higher polymer yields per amount of transition metal which is the main component of the catalyst, the concentration of transition metal supported on the carrier is low. The amount of transition metal component supported on the carrier is less than from 1 % up to 10%, by weight of the solid catalyst component. The yield of polymer per weight of supported catalyst is from several thousands up to tens of thousands times.

As mentioned earlier, there can be adverse effects of the stability of the polyolefin resins resulting from the carrier and catalyst residues remaining in the resin. Thus, the thermal stability, odor color, anticorrosivity, weathering properties and other physical properties of any molded polymer products may be impaired by the magnesium, aluminum, and other cocatalyst compounds still present in the polymer because of the catalyst residues. The problem of poor weatherability is particularly serious since large quantities of these molded polyolefin resin products are used outdoors.

The range of catalyst residues found in the polyolefin range from 10 to 1000 ppm, preferably from 10 to 500 ppm, and most preferably from 10 to 100 ppin.

A preferred composition according to the instant invention comprises a component (a) in which the catalyst residue contains aluminum, boron, titanium, zirconium, chromium, vanadium or mixtures thereof. Aluminum residues are particularly important in the context of this invention.

In general polyolefins which can be stabilized include:

1. Polymers of monoolefins and diolefins, for example polypropylene, polylsobutylene, polybut- 1 -ene, poly-4-methylpent- 1 -ene, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbomene, 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-U, medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), branched low density polyethylene (BLDPE).

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/HWE).

3. Copolymers of monoolefins and diolefins with each other or with other vinyl monomers, for example ethylenelpropylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylenelbut1-ene copolymers, propylene/isobutylene copolymers, ethylene/but-l-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylenelheptene copolymers, ethylene/octene copolymers, propylenelbutadiene copolymers, isobutylenelisoprene copolymers, ethylenelalkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/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-norbomene; and mixtures of such copolymers with one another and with polymers mentioned in 1) above, for example polypropylenelethylene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acr-ylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbon monoxide copolymers and mixtures thereof with other polymers, for example polyamides.

A preferred polyolefin polymer of this invention is a homopolymer or copolymer of propylene or ethylene; most particularly the polyolefin is polypropylene or polyethylene.

Of special preference is also a composition comprising as component (a) a polyolefin which has not undergone a deashing or related step to reduce the catalyst residue content.

The compounds of the formula I are preferably added to component (a) to be stabilized in an amount of 0.0 1 to 5 %, typically of 0.05 to 3 %, more preferably of 0. 05 to 1 %, based on the weight of component (a).

In addition to the compounds of the formula I, the novel compositions may contain further coadditives (costabilizers), typically as the following:

1. Antioxidants 1. 1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl4,6-dimethylphenol, 2,6-di-tert-butyl-4-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-l'-yl)phenol, 2,4-dimethyl-6-(1'-methylheptadec-l'- yl)phenol, 2,4-dimethyl-6-(1'methyltridec-l'-yl)phenol and mixtures thereof.

1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tertbutylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl6-ethylphenol, 2,6-di-dodecylthiomethyl-4-nonylphenol.

1.3. Hydroquinones and alkylated hydroquinones. for example 2,6-di-tertbutyl-4methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tertamylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tertbutylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis(3,5-ditert-butyl-4-hydroxyphenyl)adipate.

1.4. Tocopherols, for example (x-tocopherol, 0-tocopherol, -y-tocopherol, 8-tocopherol and mixtures thereof (vitamin E).

1.5. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tertbutyl-4-methylphenol), 2,2'-thiobis(4-octylphenol),4,4'-thiobis(6-tertbutyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2-methylphenol), 4,4'thiobis(3,6-di-sec-amylphenol), 4,4'-bis(2,6-dimethyl-4hydroxyphenyl)disulfide.

1.6. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl- 6-(cc-methylcyclohexyl)phenoll, 2,2'-methylenebis(4-methyl-6- cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4-methylphenol), 2,2'methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tertbutylphenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'methylenebis[6-(a-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis[6-((x,adimethylbenzyl)4-nonylphenoll, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tertbutyl-2-methylphenol), 1,1-bis(5-tert-butyl-4hydroxy-2-methylphenyl)butane, 2,6-bis(3_ tert-butyl-5-methyl-2hydroxybenzyl)-4-methylphenol, 1,1,3-tris(S-tert-butyl-4-hydroxy2methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-ndodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'hydroxyphenyl)butyratel, bis(3tert-butyl-4-hydroxy-5 -methyl phenyl)dicyclopentadiene, bis[2-(3'-tert-butyl-2'-hydroxy5'-methylbenzyl)6-tert-butyl-4-methylphenyllterephthalate, 1, 1-bis(3,5-dimethyl2hydroxyphenyl)butane, 2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(5-tertbutyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetra(5-tert-butyl4-hydroxy-2-methylphenyl)pentane.

1.7. 0-, N- and S-bertzyl compounds, for example 3,5,3',5'-tetra-tertbutyl-4,4'-dihydroxydibenzyl ether, octadecyl-4-hydroxy-3,5dimethylbenzylmercaptoacetate, tridecyl-4hydroxy-3,5-di-tertbutylbenzyimercaptoacetate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine, bis(4-tert-butyl-3 -hydroxy-2,6-dimethylbenzyl)dlthioterephthal ate, bis(3,5-di-tei-tbutyl-4-hydroxybenzyl)sulfide, isooctyl-3,5-di-tert-butyl4-hydroxybenzylmercaptoacetate.

1.8. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis(3,5-ditert-butyl-2hydroxybenzyl)malonate, dioctadecyl-2-(3-tert-butyl-4-hydroxy5-methylbenzyl)malonate, didodecylmercaptoethyl-2,2-bis-(3,5-di-tertbutyl-4-hydroxybenzyl)malonate, bis[4(1, 1,3,3-tetramethylbutyl)phenyll-2, 2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)m alonate.

1.9. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris(3,5-di-tertbutyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-buty]4-hydroxybenzyl)-2,3,5,6tetramethylbenzene, 2,4,6-tris(3,5-di-tert-butyl4-hydroxybenzyl)phenol.

1. 10. Triazine compounds, for example 2,4-bis(octylmercapto)-6-(3,5-ditert-butyl-4hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3, 5-di-tert-butyl-4-hydroxyphenoxy)1,3,5-triazine, 2,4,6-tris(3,5-ditertbutyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4hydroxyphenylethyl)-1,3,5-tri- azine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyi)hexahydro-1, 3,5-tria zine, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.

1. 11. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4hydroxybenzylphosphonate, diethyl-3,5-di-tert-butyl-4hydroxybenzylphosphonate, dioctadecyl-3,5-di-tertbutyl-4-hydroxybenzylphosphonate, dioctadecyl-5-tert-butyl-4-hydroxy-3methylbenzyl- phosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl- 4-hydroxybenzylphosphonic acid.

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

1. 13. Esters of 0-(3,5-di-tert-butyl-4-hydroxyphenyl)prODionic acid with mono- or poly- hydric 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(hydroxyethyl) isocyanurate, N,Y-bis(hydroxyethyl)oxamide, 3- thiaundecanol, 3-thiapentadecanol, trimethyl- hexanediol, trimethylolpropane, 4-hydroxymethyl- 1 -phospha-2,6,7- trioxabicyclo [2.2.2]octane.

1. 14. Esters of 0-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentatrythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4hydroxymethyl- I -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1. 15. Esters of 0-(3,5-dicyclohexyl-4-hydroxvphenyl)provionic 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, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N, N'bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-l-phospha-2,6,7trioxabicyclo[2.2.2]octane.

10- 1. 16. Esters of 3,5-di-tert-butvl-4-hydroxvphenyI 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, thiodlethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,Y- bis(hydroxyethyl)oxamide, 3-thlaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-l-phospha-2,6,7trioxabicyclo[2.2.2]octane.

1.17. Amides of 0-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, e.g. N,Y-bis(3,5di-tert-butyl-4-hydroxyphenylproplonyl)hexamethylenediamine, N, Y-bis(3,5-di-tertbutyl-4-hydroxyphenylpropionyl)trimethylenediarnine, N,Ybis(3,5-di-tertbutyl-4-hydroxyphenylpropionyl)hydrazine.

1. 18. Ascorbic acid (vitamin C) 1. 19. Aminic antioxidants, for example N,N'-di-isopropyl-p- phenylenediamine, N,N, -disec-butyl-p-phenylenediamine, N,N'-bis(1,4dimethylpentyl)-p-phenylenediamine, N,Ybis(l-ethyl-3-methylpentyl)-pphenylenediamine, N,N'-bis(I7methylheptyl)-p-phenylenediamine, N,N'dicyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N'-phenyl-pphenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N(l-methylheptyl)-M-phenyl-pphenylenediamine, N-cyclohexyl-N'-phenyl-pphenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl-N,N'di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4isopropoxydiphenylamine, N-phenyl- 1 -naphthylamine, N-(4tertoctylphenyl)- I -naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, for example p,p-di-tert-octyidiphenylamine, 4-nbutylaminophenol, 4-butyrylaminophenol, 4-nonanoylamino-phenol, 4dodecanoylaminophenol, 4-octadecanoylaminophenol, bis(4methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4'diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, N,N,N',N'tetramethyl-4,4'-diaminodiphenylmethane, 1,2-bis[(2methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane, (otolyl)biguanide, bis[4-(1',3'-dimethylbutyl)phenyl]an-dne, tert-octylated N-phenyl- 1 -naphthylamine, a mixture of mono- and dialkylated tertbutylltert-octyldiphenylamines, a mixture of mono- and dialkylated nonyldiphenylamines, a mixture of mono- and dialkylated dodecyidiphenylarnines, a mixture of mono- and dialkylated isopropyl/isohexyldiphenylamines, a mixture of mono- und dialkylated tertbutyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H1,4-benzothiazine, phenothiazine, a mixture of mono- und dialky- lated tert-butyl/tert-oetylphenothiazines, a mixture of mono- und dialkylated tert-octylphenothiazines, N-allylphenothiazine, N,N,N',N'tetraphenyl-1,4-diaminobut-2-ene, N,Nbis(2,2,6,6-tetramethyl-piperid-4-ylhexamethylenediamine, bis(2,2,6,6-tetramethylpiperid-4-y1)sebacate, 2,2,6, 6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.

2. UV absorbers and light stabilizers 2.1. 2-(2'-Hydroxyphenyl)benzotriazoles, for example 2-(2'-hydroxy-5'methylphenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl2'hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-(1, 1,3,3tetramethylbutyl)phenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'hydroxyphenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl- 2'-hydroxy-5'methylphenyl)-5-chlorobenzotnazole, 2-(3'-sec-butyl-5'-tert-buty12'hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-4'octyloxyphenyl)benzotriazole, 2-(Y,Ydi-tert-amyl-2'hydroxyphenyl)benzotriazole, 2-(3',5'-bis-(a,(x-dimethylbenzyl)2'hydroxyphenyl)benzotriazole, mixture of 2-(3'-tert-butyl-2'-hydroxy-5'(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl5'-[2-(2-ethylhexyloxy)-carbonylethyl]-2'-hydroxyphenyl)-5chlorobenzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'(2methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl-2'hydroxy-5'-(2methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tertbutyl-5'-[2-(2-ethylhexyloxy)carbonylethyl] -2'hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'methylphenyl)benzotriazole, and 2-(3'-tert-butyl-2'-hydroxy-5'-(2isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2'-methylenebis[4-(1,1,3, 3-tetramethylbutyl)-6-benzotriazol-2-Ylphenoll; the transesterification product of 2-[3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]2H-benzotriazole with polyethylene glycol 300; rR-CI-12CH2COO(CH2)3jjwhere R = 3'-tert-butyl-4'-hydroxy-5'-2H-benzotriazol-2ylphenyl.

2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and Thydroxy-4,4'-dimethoxy derivatives.

2.3. Esters of substituted and unsubstituted benzoic acids, for example 4tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis(4-tert-butylbenzoyl) resorcinol, benzoyl resorcinol, 2,4-di-tertbutylphenyl 3,5-di-tert-butyl-4hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tertbutyl4hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4hydroxy- benzoate.

2.4. Acrylates. for example ethyl (x-cyano-p,p-diphenylacry late, isooctyl a.-cyano-p,p-di- phenylacrylate, methyl (x-carbomethoxycinnamate, methyl (x-cyano-p-methyl- p-methoxycinnamate, butyl (x-cyano-p-methyl-p-methoxy-cinnamate, methyl cc-carbomethoxy-pmethoxycinnamate and N-(p-carbomethoxy-o-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis-[4(1,1,3,3 -tetramethylbutyl)phenoll, such as the 1: 1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolamine or NcyclohexyIdiethanolarnine, nickel dibutyIdithlocarbamate, nickel salts of the monoalkyl esters, e.g. the methyl or ethyl ester of 4hydroxy-3,5-ditert-butylbenzylphosphonic acid, nickel complexes of ketoximes, e.g. of 2hydroxy-4-methylphenyl undecyIketoxime, nickel complexes of 1 -phenyl-41auroyl-5hydroxypyrazole, with or without additional ligands.

2.6. 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-pentamethyl-4-piperidyl)sebacate, bis(l-oetyloxy-2,2,6,6tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl4-piperidyl) nbutyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1(2hydroxyethyl)-2,2,6,6-tetrwnethyl-4-hydroxypiperidine and succinic acid, the condensate of N,N'-bis(2,2,6,6-tetramethyl-4piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate, 1, 1'-(1,2-ethanedlyl)-bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2, 2,6,6-tetramethylpiperidine, 4- stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6- pentamethylpiperidyl)-2-n-butyl2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,-7,9,9tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, bis(l-octyloxy-2,2,6, 6-tetramethylpiperidyl)sebacate, bis(loctyloxy-2,2,6,6-tetramethylpiperidyl)succinate, the condensate of N,Mbis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-morpholino2,6-dichloro-1,3,5-triazine, the condensate of 2-chloro-4,6-bis(4-nbutylamino-2,2,6,6-tetramethylpiperidyI)-1,3,5-triazine and 1,2-bis(3aminopropylamino)ethane, the condensate of 2-chloro-4,6-bis(4-nbutylamino1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triaz ine and 1,2-bis-(3aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8triazaspiro[4.5]decane-2,4dione, 3-dodecyl-l-(2,2,6,6-tetramethyl-4piperidyl)pyrrolidine-2,5-dione, 3-dodecyl-l(1,2,2,6,6-pentamethyl-4piperidyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxyand 4stearyloxy-2,2,6,6-tetramethylpiperidine, a condensation product of N,N'bis- (2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro- 1,3,5-triazine, a condensation product of 1, 2-bis(3-aminopropylarnino)ethane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylaniino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [ 136504-96-61); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimide, N(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimide, 2-undecyl-7,7, 9,9-tetramethyl- l -oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl- l -oxa-3,8-diaza-4oxospiro [4,51decane und epichlorohydrin.

2.7. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'diethoxyoxanilide, 2,T-dioctyloxy-5,5'-di-tert-butoxanilide, 2,2'didodecyloxy-5,5'-di-tert-butoxanilide, 2-edioxy-2'ethyloxanilide, N,N'bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2'-ethoxanilide and the mixture thereof with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide and mixtures of ortho- and para-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.

2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2hydroxy-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)-4,6bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4bis(2-hydroxy-4propyloxyphenyl)-6-(2,4-dimethylphenyl)- 1,3,5-triazine, 2-(2-hydroxy4octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin e, 2-(2hydroxy-4-tridecyloxyphenyl)4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2[2-hydroxy-4-(2-hydroxy-3-butyloxy-propoxy)phenyll-4,6-bis(2,4-dimethyl)1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-oetyloxy-propyloxy)phenyll-4, 6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy/tridecyloxy-2hydroxypropoxy)-2-hydroxy-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5triazine, 2[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy)phenyll-4-,6bis(2,4-dimethy lphenyl)1,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4, 6-diphenyl-l-,3,5-triazine, 2-(2hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3, 5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxy-propoxy)phenyll-1, 3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl- 1,3,5triazine.

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

4. Phosphites and phosphonite, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritoI diphosphite, diisodecyloxypentaerythritol diphosphite, bis(2,4-di-tertbutyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tris(tertbutylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphonite, 6isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosph ocine, 6-fluoro2,4,8,10-tetra-tert-butyl-12-methyldibenzo[d,g]-1,3,2dioxaphospho cin, bis(2,4-di-tertbutyl-6-methylphenyl)methylphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethylphosphite.

5. Hydroxylamines, for example, N,N-dibenzyIhydroxylarnine, N,Ndiethylhydroxylamine, N,N-dioctylhydroxylarnine, N,Ndilaurylhydroxylamine, N,N-ditetradecylliydroxylamine, N,Ndihexadecylhydroxylarnine, N,N-dioctadecylhydroxylarnine, N-hexadecyl-Noctadecylhydroxylamine, N-heptadecyl-N-octadecylhydroxylamine, N,Ndialkylhydroxylamine derived from hydrogenated tallow amine.

6. Nitrones, for example N-benzyI-alpha-phenyl-nitrone, N-ethyl-alphamethyl-nitrone, N-octyl-alpha-heptyl-nitrone, N-lauryl-alpha-undecylnitrone, N-tetradecyl-alpha-tridecyl-nitrone, N-hexadecyl-alphapentadecyl-nitrone, N-octadecyl-alpha-heptadecyl-nitrone, N-hexadecylalpha-heptadecyl-nitrone, N-ocatadecyl-alpha-pentadecyl-nitrone, Nheptadecyl-alpha-heptadecyl-nitrone, N-octadecyl-alpha-hexadeoyl-nitrone, nitrone derived from N,N-dialkylhydroxylarnine derived from hydrogenated tallow amine.

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

8. Peroxide scavengers, for example esters of P-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(pdodecylmercapto)propionate.

9. Basic co-stabilizers, for example melamine, polyvinylpyrrolidone, dicyandiamide, tri- allyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids, e.g. calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate or tin pyrocatecholate.

10. Nucleating agents, for example inorganic substances such as talcum, metal oxides such as titanium dioxide or magnesium oxide, phosphates, carbonates or sulfates of, preferably, alkaline earth metals; 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 beads, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite, sawdust or fibers of other natural products, synthetic fibers.

12. Other additives. for example, plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, fluorescent whitening agents, flame-proofing agents, antistatic agents and blowing agents.

13. Benzofuran-2-ones and indolinones, for example those disclosed in USA-4 325 863, US-A-4 338 244, US-A-5 175 312, US-A-5 216 052, US-A-5 252 643, DE-A-4 316 611, DE-A-4 316 622, DE-A-4 316 876, EP-A-0 589 839 or EPA-0 591 102 or 3-[4-(2-acetoxyethoxy)phenyll-5,7-di-tert-butylbenzofuran2-one, 5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyllbenzofuran-2one, 3,3'-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2one], 5,7-di-tert-butyl-3-(4-ethoxyphonyl)benzofuran-2-one, 3-(4acetoxy-3, 5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one, 3-(3,5-dimethyl-4pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one, 3-(3,4dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(2,3dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-on.

With the exception of the benzofuran-2-ones listed in item 13, the costabilizers are added typically in concentrations of 0.01 to 10%, based on the total weight of the material to be stabilized.

Further preferred compositions comprise, besides components (a) and (b) further additives, preferably phenolic antioxidants, light stabilizers and/or processing stabilizers.

Particularly preferred additives are phenolic antioxidants (item 1 in the list), sterically hindered amines (item 2.6 in the list) and peroxide scavengers (item 8 in the list).

The phenolic antioxidant of particular interest is selected from the group consisting of n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, neopentanetetrayl tetrakis(3,5di-tert-butyl-4-hydroxyhydrocinammate), din-octadecyl 3,5-ditert-butyl-4-hydroxybenzylphosphonate, 1,3,5-tris(3,5di-tert-butyl-4-hydroxybenzyl)isocyanurate, thiodiethylene bis(3,5-ditert-butyl-4-hydroxyhydrocinnamate), 1,3,5-trimethyl-2,4,6-tris(3,5-ditertbutyl-4-hydroxybenzyl)benzene, 3,6-dioxaoctamethylene bis(3-methyl-5tert-butyl-4hydroxyhydrocinnamate), 2,6-di-tert-butyl-p-cresol, 2,2'ethylidene-bis(4,6-di-tert-butylphenol), 1,3,5-tris(2,6-dimethyl-4-tertbutyl-3-hydroxybenzyl)isocynurate, 1,1,3-tris(2methyl-4-hydroxy-5-tertbutylphenyl)butane, 1,3,5-tris[2-(3,5-di-tert-butyl-4hydroxyhydrocinnamoyloxy)ethyllisocyanurate, 3,5-di-(3,5-di-tert-butyl-4hydroxybenzy1)mesitol, hexamethylene bis(3,5-di-tert-butyl-4hydroxyhydrocinnamate), 1-(3,5-di-tert-butyl-4hydroxyanilino)-3,5di(octylthio)-s-triazine, N,N'-hexamethylene-bis(3,5-di-tert-butyl4hydroxyhydrocinnarnamide), calcium bis(ethyl 3,5-di-tert-butyl-4hydroxybenzylphosphonate), ethylene bis[3,3-di(3-tert-butyl-4hydroxyphenyl)butyratel, octyl 3,5-di-tert-butyl4hydroxybenzylmercaptoacetate, bis(3,5-di-tert-butyl-4hydroxyhydrocinnamoyl)hydrazide, and N,N'-bis[2-(3,5-di-tert-butyl-4hydroxyhydrocinnamoyloxy)-ethyl]-oxamide.

A most preferred phenolic antioxidant is neopentanctetrayl tetrakis(3,5di-tert-butyl-4hydroxyhydrocinnarnate), n-octadecyl 3,5-di-tert-butyl-4hydroxyhydrocinnamate, 1,3,5trimethyl-2,4,6-tris(3,5-di-tert-butyl-4hydroxybenzyl)benzene, 1,3,5-tris(3,5-di-tertbutyl-4hydroxybenzyl)isocyanurate, 2,6-di-tert-butyl-p-cresol or 2,2'-ethylidenebis(4,6di-tert-butylphenol).

The trialkanolamine trisphosphites of the formula I of component (b) protect phenolic antioxidants used in polyolefins containing catalyst residue, especially aluminum residues, 0 from discoloration and provides excellent color to the polyolefin resin.

The hindered amine compound of particular interest is selected from the group consisting of bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate, bis(1,2,2,6,6-pentamethylpiperidin-4yl) sebacate, di(1,2,2,6,6pentamethylpiperidin-4-yl) (3,5-di-tert-butyl-4hydroxybenzyl)butylmalonate, 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4stearyloxy-2,2,6,6-tetramethylpiperidine, 3-n-octyl-7,7,9,9-tetramethyl-1, 3,8-tn'aza-spiro[4.5]decane-2,4-dione, tris(2,2,6,6-tetramethylpiperidin-4-yl) nitrilotri acetate, 1,2-bis(2,2,6, 6-tetramethyl-3-oxopiperazin-4-yl)ethane, 2,2,4,4-tetramethyl-7-oxa-3,20diaza-21-oxodispiro[5.1.11.21 henelcosane, polycondensation product of 2, 4-dichloro-6-tert-octylamino-s-triazine and 4,4'hexamethylenebis(amino-2, 2,6,6-tetramethylpiperidine), polycondensation product of I(2hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and suceinic acid, polycondensation product of 4,4'-hexamethylenebis-(amino-2,2,6,6tetramethylpiperidine) and 1,2-dibromoethane, tetrakis(2,2,6,6tetramethylpiperidin-4-yl) 1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2, 6,6-pentamethylpiperidin-4-yl) 1,2,3,4-butanetetracarboxylate, polycondensation product of 2,4-dichloro-6-morpholino-s-triazine and 4,4'hexamethylenebis(amino2,2,6,6-tetramethylpiperidine), N,N',N",N"'tetrakis[(4,6-bis(butyl-2,2,6,6-tetramethylpiperidin-4-yl)-amino-striazin-2-yl]- 1, 1 0-diamino-4,7-diaza decane, mixed [2,2,6,6tetramethylpiperidin-4-yl/O,P,P',P'-tetramethyl-3,9-(2,4,8,10-tet raoxaspiro[5.5]-undecane) diethyl] 1,2,3,4-butanetetracarboxylate, mixed [1,2,2,6,6-pentamethylpiperidin4-yllp,P,P',P'-tetramethyl-3,9-(2,4,8,10tetraoxaspiro[5.5]undecane)diethy l] 1,2,3,4butanetetracarboxylate, octamethylene bis(2,2,6,6-tetramethylpiperidin-4-carboxylate), 4,4'ethylenebis(2,2,6,6-tetramethylpiperazin- 3 -one), and bis(l-octyloxy-2,2, 6,6-tetramethylpiperidin-4-yl) sebacate.

A most preferred hindered amine compound is bis(2,2,6,6tetramethylpiperidin-4-yl) sebacate, the polycondensation product of 1-(2hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the polycondensation product of 2,4-dichloro-6-tert-octylamino-s-triazine and 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine)' N,N',N%N" -tetrakis[(4,6-bis(butyl-(2,2,6,6-tetramethyl-piperidin-4-yl)amino)-stria zine2-yl]- 1, 1 0-diamino-4,7-diazadecane or bis(l -octyloxy-2,2,6,6tetramethylpiperidin-4-yl) sebacate.

Further additives (stabilizers) which are also particularly preferred are benzofuran-2-ones, such as those disclosed, inter alia, in US-A-4 325 863, US-A-4 338 244, US-A-5 175 312, US-A-5 216 052, US-A-5 252 643, DE-A-4 316 611, DE-A-4 316 622, DE-A-4 316 876, EP-A-0 589 839 and EP-A-0 591 102.

Examples of such benzofuran-2-ones are compounds of formula R15 R14 0 co R1 3 c W12 H R', 1 wherein R', 1 is an unsubstituted or substituted carbocyclic or heterocyclic aromatic ring system; W12 is hydrogen; R' 14is hydrogen, alkyl of 1 to 12 carbon atoms, cyclopentyl, cyclohexyl or chloro; 0 W13 has the meaning of W12 or R' 14or is a radical of formula -(CH2 --OR'16' S 0 0 0 11 11 11 -(CH2Y,-C-.NK'17)2, ----CH2+,-C-O-A-0-C--CH -,E, S S 2s 0 0 0 0 -(CH -(CH2),-C-NR'18-A-iNK-18-t--CH2),-E A-C-NW, 8-A-0-C-(CH2),-E 0 0 0 11 /111 11 ---CH2-)-s-L- N \--/ N -L-CH2-s E, -CH2-S-R'19, -CH(C6H5)-C-OR'16 or -D-E, wherein W16 is hydrogen, alkyl of 1 to 18 carbon atoms, alkyl of 2 to 18 carbon atoms which is interrupted by oxygen or sulfur, dialkylaminoalkyl having a total of 3 to 16 carbon atoms, cyclopentyl, cyclohexyl, phenyl or phenyl which is substituted by 1 to 3 alkyl radicals having a total of at most 18 carbon atoms; s is 0, 1 or 2; substituents W17 are each independently of one another hydrogen, alkyl of 1 to 18 carbon atoms, cyclopentyl, cyclohexyl, phenyl; phenyl which is substituted by 1 or 2 alkyl radicals having a total of at most 16 carbon atoms, a radical of formula -CAOH, 0 11 -C2H4-0-C,H2t,l or or, together with the linking nitrogen atom, form a -C2H4-0-C-R'20, piperidine or morpholine radical; t is 1 to 18; W20 is hydrogen, alkyl of 1 to 22 carbon atoms, or cycloalkyl of 5 to 12 carbon atoms; 0 19- A is alkylene of 2 to 22 carbon atoms which may be interrupted by nitrogen, oxygen or sulfur; R'18 is hydrogen, alkyl of 1 to 18 carbon atoms, cyclopentyl, cyclohexyl, phenyl; phenyl which is substituted by 1 or 2 alkyl radicals having a total of at most 16 carbon atoms, or benzyl; R'19 is alkyl of 1 to 18 carbon atoms; D 'S -0-, -S-, -SO-, -S02- or - C(R'202-; substituents W.21 are each independently of one another h drogen, Cl-C16alkyl, the two y C, R'21 radicals together containing 1 to 16 carbon atoms, and R'21 is furthermore phenyl or a 0 0 11 11 radical of formula --Lh2J--S---,,-OR'16 or ----tk.t12Y-S--4-- N(R'17)2 wherein s, W1r, and R'17 are as defined above; E is a radical of formula R, is R14 0 co C 12 1 wherein R', 1, R'1 2 and R'1 4 are as defined above; and WIS is hydrogen, alkyl of 1 to 20 carbon atoms, cyclopentyl, cyclohexyl, chloro, or a 0 0 11 11 radical of formula 16 or -CH2-C-N(R',7)2' Wherein R'16 and R'17 are as defined above, or R'15 and R'14, taken together, form a tetrmethylene radical.

Preferred benzofuran-2-ones are those wherein R'13 is hydrogen, alkyl of 1 to 12 carbon atoms, cyclopentyl, cyclohexyl, chloro or a radical of formula ----CH2)-- OR'16 S or -D-E, wherein s, R' ----CH2Y S -C-N(W17)2 16, W17, D and E are as defined above, and R'16 'S preferably hydrogen, alkyl of 1 to 18 carbon atoms, cyclopentyl or cyclohexyl.

Preferred benzofuran-2-ones are also those wherein R', 1 is phenyl or phenyl which is substituted by 1 or 2 alkyl radicals having a total of at most 12 carbon atoms; W12 'S hydrogen; W14 is hydrogen or alkyl of 1 to 12 carbon atoms; W13 is hydrogen, alkyl of 1 0 0 11 11 R') or -D-E; WIS is to 12 carbon atoms, ----Ck'2)-S'-OR'16 17 2 0 hydrogen, alkyl of 1 to 20 carbon atoms, -CH2-C-OR'16 or -Lk12-L- 1N(W17)2, or W15 and W14, taken together, form a tetramethylene radical, in which groups s, R'16, R' 17, D and E are as defined at the outset.

Particularly interesting benzofuran-2-ones are also those wherein W13 is hydrogen, alkyl of 1 to 12 carbon atoms or -D-E; W12 and W14 are each independently of the other hydrogen or alkyl of 1 to 4 carbon atoms; WIS is alkyl of 1 to 20 carbon atoms, and D and E are as defined at the outset.

Of particular interest are finally also those benzofuran-2-ones, wherein W13 is alkyl of 1 to 4 carbon atoms or -D-E; W12 and W14 are hydrogen; W15 is alkyl of 1 to 4 carbon atoms, cyclopentyl or cyclohexyl, D is a C(R'202- group, and E is a radical of formula R', 5 W1 4 0 co R1 2 H R1 1 the substituents W21 being identical or different and are each alkyl of 1 to 4 carbon atoms, :D and R', 1, W1 2, W14 and W1 5 are as defined above.

The amount of benzofuran-2-ones additionally employed can vary within wide limits. The novel compositions may typically contain them in amounts of 0.0005 to 10 % by weight, preferably of 0.001 to 5 % by weight, most preferably of 0.01 to 2 % by weight.

A preferred embodiment of this invention is the use of a compound of the formula I for stabilizing a polyolefin against oxidative, thermal and/or light-induced degradation, comc prising at least one transition-metal or main-group metal or mixture thereof residue in an amount of 10 to 1000 ppm as a result of said metal being used as a catalyst or cocatalyst to effect polymerization of said polyolefin.

The invention also relates to a process for stabilizing a polyolefin against oxidative, thermal and/or light-induced degradation, comprising at least one transition-metal or maingroup metal or mixture thereof residue in an amount of 10 to 1000 ppm as a result of said metal being used as a catalyst or cocatalyst to effect polymerization of said polyolefin, which process comprises incorporating therein or applying thereto a compound of the formula I according to component (b).

The following examples illustrate the invention more fully. Parts and percentages are by weight.

Example 1: Stabilization of polypropylene.

The following general procedure is used for preparing the various polypropylene formulations where the additives are melt compounded into the polymer.

Into 1000 grams of Himont ProfaxO 6501 (bulk phase polymerization) polypropylene powder is added the various test additives at the concentration set forth in the various examples and in the tables below. The concentration of the phenolic antioxidant is set at 750 ppm. The acid scavenger, calcium stearate, is used at 750 ppm also. The concentration of triethylaluminum is varied from 0 to 500 ppm which corresponds to 0 to about 112 ppm of aluminum in the final formulations.

The resultant blended powder is further tumble blended for 20 minutes on a Turbula mixer. The blended mixture is then melt compounded using a 2.54 cm Superior MPM extruded fitted with a polyolefin compounding screw with a Maddock mixing section in the metering zone of the screw. The temperature of the exit die is set at 2740C. The extruded molten strand is quenched in a water bath and pelletized using a Conair strand cutter. A 100 gram aliquot of the pellets from this first pass extrusion is retained for further testing, and the remainder of the extrudate is pass through the extruder again. In this fashion, retains of the pellets are collected for the third and fifth pass extrudate.

The polypropylene pellets are tested for melt flow rate using ASTM method 1238-90 on a Tinius-01sen extrusion plastometer filled with a 2.16 kg weialit at 2300C. Yellowness in- Z b dex is measured using ASTM method 1925-90 on an Applied Color Systems Spectrophotometer with the large area view orifice, spectral component included, C illuminant, 21 observe on 3.175 mm compression molded plaques.

Polymer: Himont Profaxg 6501 polypropylene, Ti/A1 catalyst; Sphedpol Process; Nominal melt index = 5.3 dg/min at 2.16 kg/2301C. Extrusion Conditions: Zone 1 at 2460C. Zone 2 at 2600C. Zone 3 at 2741C. Zone 4 at 2740C. Extruded with hopper open to air at 90 rpm. Residence time approximately 1 minute in barrel. Extruder: Superior MPM 2.54 cm; 241 IM. Screen pack: 20-60-100-60-20. Screw Design: polyolefin screw with Maddock Mixing Head. Compression Molding: 2320C, 3 minutes low pressure, 3 minutes high pressure, 3 minutes cooling.

Example 1 illustrates the prevention of color formation from the 1 st to the 5th pass in polypropylene compositions containing 750 ppm of neopentanetetrayl tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), Irganox( 1010 (Ciba Specialty Chemicals), and 0 or 750 ppm of a compound of formula I where n is 0, Q is a direct bond, A,-A3 are each ethylene, YVY6 and Z1-4 are each tert-butyl, IrgafosO 12 (Ciba Specialty Chemicals), and various amounts of aluminum metal so as to provide various levels of residual aluminum in the composition. The ability of the instant compound of formula I to prevent discoloration is seen by inspection of the Yellowness Index values seen in the table 1 below for each level of residual aluminum. in the composition. lower YI values indicate less discoloration.

Table 1:

Compound of the Triethyl Aluminum Yellowness Index formula I (Ppm) (Ppm) [ppm as AI] I st pass 5th pass 0 0 0 7.45 8.85 750 0 0 6.62 8.17 0 10 2 7.74 9.54 750 10 2 6.64 8.04 0 50 12 7.48 10.11 750 so 12 6.85 7.90 0 100 24 7.35 9.62 750 100 24 7.01 8.21 0 500 118 7.47 10.44 750 500 118 7.04 8.51 IrgafosO 12 (Ciba Specialty Chemicals) is a compound of the formula Ia H3C -, c / CH3 CH3 CH3 i tl3U L; 0 CH3 P -0 CH2-CH2- N (Ia) CH3 M3(i CH3 c 111 CH3 L H3C \ CH3 Example 2: Stabilization of polypropylene.

When 750 ppm of IrganoxO 1010 in the compositions of Example 1 is replaced with 750 ppm of N,N',N'-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, Irganox@ 3114 (Ciba Specialty Chemicals), the same stabilizing effect of the Irgafos@ 12 (Ciba Specialty Chemicals, a compound of the formula 1, see example 1) is seen on preventing discoloration in the polypropylene containing various levels of aluminum residues as seen in the table 2 below.

Table 2:

Compound of the Triethyl Aluminum Yellowness Index formula I (Ppm) (Ppm) [ppm as All 1 st pass 5th pass 0 0 0 7.98 9.98 750 0 0 7.54 7.96 0 10 2 8.06 10.48 750 10 2 8.15 9.53 0 50 12 7.73 10.55 750 50 12 8.45 8.81 0 100 24 8.41 10.36 750 100 24 8.27 8.66 It is clear from the data given in Examples 1 and 2 that the addition of a trialkanolamine trisphosphite protects the polyolefin from discoloration even when a significant amount of a metal catalyst or cocatalyst residue is present.

Example 3 ': This example illustrates the ability of the compounds of formula I, such as Irgafos@ 12 (Ciba Specialty Chemicals, see Example 1) to complex with a trialkylaluminum compound. All manipulations with Trialkylaluminum are carried out in a dry box under an argron atmosphere with the rigorous exclusion of moisture.

To a solution of 2 grams (1.37 mmol) of IrgafosO 12 in 4 mi of chloroform is added 1.37 mI (1.37 mmol) of a 1 molar hexane solution of triethyialuminum. The 31p(lH} rimr spectrum shows resonances at 5 132.8 ppm and 32.7 ppin whereas uncomplexed Irgafos@ 12 has a singlet resonance at 3 137.1 ppin.

Example 4: This example shows that not all phosphites complex with trialkylaluminum compounds.

The procedure of Example 3 is repeated with 0.88 (1.37 mmol) of tris(2,4di-tert-butylphenyl) phosphite, IrgafoxO 168 (Ciba Specialty Chemicals), 1.37 ml (1.37 mmol) of a 1 molar hexane solution of triethylaluminum and 4 ml of chloroform. No complexation is observed as seen by the rimr data.

WHAT IS CLARAED IS:

1. A composition comprising a) a polyolefin subject to oxidative, thermal andlor light-induced degradation comprising at least one transition-metal or main-group metal or mixture thereof residue in an amount of 10 to 1000 ppm as a result of said metal being used as a catalyst or cocatalyst to effect polymerization of said polyolefin, and b) an effective stabilizing amount of a compound of the formula 1 Z1 Z2 Y1 Y2 14 n 0 p 0 1 U 1 A3 Y5 A A Y3 0 --- p 0 0 p 0 Z6 n 1 1 (0)n Z3 0 0 Z5 Y6 Y4 Z4 wherein n is 0 or 1, when n Is 0, Q is a direct bond, or when n is 1, Q is -S- or -CRIR2wherein R, and R2 are independently hydrogen, straight or branched chain alkyl of 1 to 18 carbon atoms, phenyl, tolyl or anisyl, Y1, Y2, Y3, Y4, Y5, Y6, Z1, Z2, Z3, Z4, Z5 and Z6 are independently hydrogen, a straight or 0 branched chain alkyl of 1 to 18 carbon atoms, bicyloalkyl of 7 to 10 carbon atoms, phenyl, benzyl, 1-phenethyl, cyclohexyl, 1-methylcyclohexyl, cyano, halogen, nitro, trifluoromethyl, hydroxy, amino, alkanoyl of 2 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms or E1EAS' where E,, E2and E3 are independently hydrogen, alkyl of 1 to 4 carbon atoms or phenyl, and & A2 and A3 are independently straight or branched alkylene of 1 to 18 carbon atoms, cycloOúylene of 5 to 6 carbon atoms or a branched chain alkylene of 1 to 8 carbon atoms with a stereocenter.

2. A composition according to claim 1 wherein n is 0 or 1, when n is 0, Q is a direct bond, or when n is 1, Q is methylene or ethylidene, Y1, Y2, Y3, Y4, YS, Y6, ZI, Z2, Z3, 4,4 and 4 are each tert-butyl, and A,, A2 and A3 are each ethylene or 2-propylene where the secondary carbon is attached to the oxygen atom.

3. A composition according to claim 1 wherein n is 0, Q is a direct bond, Y1, Y2, Y3, Y4, Y5, Y6, ZI, Z2, Z3, Z4, Z.5 and 4 are each tert-butyl, and & A2 and A3 are each ethylene.

4. A composition according to any preceding claim wherein the catalyst residue contains aluminium, boron, titanium, zirconium, chromium, vanadium or mixtures thereof.

5. A composition according to any preceding claim wherein the catalyst residue contains aluminium.

6. A composition according to any preceding claim wherein the polyolefin is a homopolymer or copolymer of propylene or ethylene.

7. A composition according to any preceding claim wherein the polyolefin is polypropylene or polyethylene.

8. A composition according to any preceding claim wherein the polyolefin has not undergone a deashing or related step to reduce the catalyst residue content 9. A composition according to any preceding claim which contains component (b) in an amount of 0.01 to 5%, based on the weight of component (a).

10. A composition according to any preceding claim which additionally contains a phenolic antioxidant, a light stabiliser andlor a processing stabiliser.

11. A composition according to any preceding claim which additionally contains as a coadditive at least one compound of the benzofuran-2-one type.

12. A process for stabilising a polyolefin against oxidative, thermal andlor light-induced degradation, comprising at least one transitionmetal or main-group metal or mixture thereof residue in an amount of 10 to 1000 ppm as a results of said metal being used as a catalyst or cocatalyst to effect'polymerisation of said polyolefin, which process comprises incorporating therein or applying thereto a compound of the formula I according to component (b) of claim 1.

13. Use of a compound of the formula I according to component (b) of claim 1 for stabilising a polyolefin against oxidative, thermal andfor light-induced degradation, comprising at least one transition -metal or main-group metal or mixture thereof residue in an anwunt of 10 to 1000 ppm as a result of said metal being used as a catalyst or cocatalyst to effect polymerisation of said polyolefin.

14. A composition according to claim 1 substantially as hereinbefore described with reference to any one of the foregoing Examples.