CA2201093A1 - Polyolefins containing catalyst residues stabilized with trialkanolaminetrisphosphites - Google Patents

Abstract

Polyolefins prepared using new supported catalysts the residues of which are not removed from said polyolefin exhibit difficult stabilization problems, especially poor weatherability, caused by the presence of said residues still remaining in the polyolefin. The use of trialkanolamine trisphosphites ameliorates these stabilization difficulties and leads to excellent polymer stabilization inspite of the catalyst residues.

Description

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Polyolefins containin~ catalyst residues stabilized with trialkanoLamine trisphosphites The instant invention pertains to polyolefins containing catalyst residues which are stabi-lized 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 l~ngineering, 1st Ed., Wiley Interscience, New York, Vol. 6, 1986, p 429; and D. L. Beach et al., ibid. page 454]. Stereoregular polypropylene was discovered soon thereafter [G. Natta et al., J. Am. Chem. Soc., 37 1708 (1955); R. B. Lieberman, ~ncyclopedia of Polymer Science and Engineering, 1 st Ed, Wiley-iInterscience, New ~ork, Vol. 13, 1986, p 429; and P. Pino et al. Angew. Chem. Int. Ed. Engl., 19, 857 (1980)].

Over the last forty years, the area of polymerization research and technology has under-gone 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. Lie-berman, loc cit; and P. Pino et al., loc cit]. There are also a wide range of transition me-tal-based catalyst families for the olefin polymerization reaction, such a titanium, vana-dium, chromium and zirconium. There are also various cocatalysts based on alkylalumi-num 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. Kaminsky, Catal. To-day, 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 non-coordinating boron reagents [A.
D. Horton, Trend in Poly. Sci., 2, 158 (1994)].

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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. Lieber-man, loc cit]. Catalyst removal or deactivation was considered necessary because the cata-lyst residue levels were high and their impact was found to be quite deleterious to the ulti-mate 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 rea-gents 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 im-purities, namely the catalyst residues. The high demand for both polyethylene and poly-propylene 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 treat-ments 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 stabiliza-tion efficacy.

United States Patent No. 5,488,079 teaches that polyolefin compositions produced in the presence of a Ziegler or metallocene type catalyst from which the catalyst has not been re-moved from the polyolefin can be stabilized by the addition of a substituted phosphine such as tris(2,4-di-tert-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 trialkanolamine trisphosphites useful for stabilizing the polyolefins are described in United States Patent Nos. 5,276,076; 5,326,802; 5,331,031; 5,334,739; 5,344,860;

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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 and/or light-induced degradation com-prising at least one transition-metal or main-group metal or mixture thereof resi-due in an amount of lO to lOOO ppm as a result of said metal being used as a cata-lyst or cocatalyst to effect polymerization of said polyolefin, and b) an effective stabilizing amount of a compound of the formula I

Zl Z2 Yl-~-(Q)~-Y2 O O
o (I) ~,~ ~A1 A2 wherein nisOor l, when n is 0, Q is a direct bond, or when n is l, Q is -S- or -CRlR2- wherein Rl and R2 are independently hydrogen, straight or branched chain alkyl of l to l 8 carbon atoms, phenyl, tolyl or anisyl, Yl, Y2, Y3, Y4, Y5, Y6, Zl~ Z2~ Z3, Z4, Z5 and Z6 are independently hydrogen, a straight or ~ ~2~1 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, trifluoro-methyl, hydroxy, amino, alkanoyl of 2 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms or ElE2E3Si where El, E2and E3 are independently hydrogen, alkyl of l to 4 carbon atoms or phenyl, and A1, A2 and A3 are independently straight or branched alkylene of 1 to 18 carbon atoms, cycloalkylene of S to 6 carbon atoms or a branched chain alkylene of 1 to 8 carbon atoms with a stereocenter.

When any of Rl or R2, Yl to Y6, Zl to Z6 and Al 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, tert-amyl, 2-ethylhexylj n-octyl, tert-octyl, lauryl, n-octadecyl, eicosyl and triacontyl; when said radicals are bicycloalkyl of 7 to 10 carbon atoms, they are, for example, isobornyl or ~d~ rltyl; 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, n-bu-toxy, n-pentoxy, hexyloxy, heptyloxy or decyloxy.

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

Preference is given to compositions in which in component (b) n is O or l, when n is 0, Q is a direct bond, or when n is 1, Q is methylene or ethylidene, Yl, Y2, Y3, Y4, Y5, Y6, Zl~ Z2~ Z3, Z4, Z5 and Z6 are each tert-butyl, and Al, 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, ~ ~ 2 0 ! 'J -3 ~

Yl, Y2, Y3, Y4, Ys, Y6, Zl~ Z27 Z3, Z4, Z5 and Z6 are each tert-butyl, and Al, 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 trichloride-aluminum 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 ear-lier. While such supported catalysts provide higher polymer yields per amount of transi-tion metal which is the main component of the catalyst, the concentration of transition me-tal 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 mol-ded polyolefin resin products are used outdoors.

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

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

In general polyolefins which can be stabilized include:

~ -6- ~2U ~ 0':,~3 1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, polybut- 1 -ene, poly-4-methylpent- 1 -ene, polyisoprene or polybutadiene, as well as poly-mers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene (which optionally can be crosslinked), for example high density polyethylene (HDPE), high den-sity and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), 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, PP/LDPE) and mixtures of different types of polyethylene (for example LDPE/HDPE).

3. Copolymers of monoolefins and diolefins with each other or with other vinyl mono-mers, for example ethylene/propylene copolymers, linear low density polyethylene(LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylene/but-1-ene copolymers, propylene/isobutylene copolymers, ethylenetbut- 1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, propylene/butadiene copolymers, isobutylene/-isoprene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers and their copolymers with carbon mon-oxide or ethylene/acrylic acid copolymers and their salts (ionomers) as well as terpoly-mers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethy-lidene-norbornene; and mixtures of such copolymers with one another and with polymers mentioned in 1) above, for example polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbon mon-oxide 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 7 '~ 2 a ~

an amount of 0.01 to S %, typically of O.OS 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-butyl-4,6-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-methylcyclo-hexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl4-methoxymethylphenol, nonylphenols which are linear or branched in the side chains, for example, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1'-methyl-undec- 1 '-yl)phenol, 2,4-dimethyl-6-( 1 '-methylheptadec- 1 '-yl)phenol, 2,4-dimethyl-6-( 1'-methyltridec- 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-di-do-decylthiomethyl -4-nonylphenol .

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

1.4. Tocopherols, for example oc-tocopherol, ~-tocopherol, ~-tocopherol, ~-tocopherol and mixtures thereof (vitamin E).

1.5. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methyl-phenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thio-bis(6-tert-butyl-2-methylphenol), 4,4'-thiobis(3,6-di-sec-amylphenol), 4,4'-bis(2,6-dim-ethyl-4-hydroxyphenyl)disulfide.

1.6. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), -8- 220~ar-~) 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(a-methyl-cyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methy-lenebis[6-(a-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis[6-(a~,a-dimethylbenzyl)-4-nonylphenol], 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-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-dodecylmer-captobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-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-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7. O-, N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxy-dibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)-amine, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoace-tate.

1.8. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate, dioctadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malo-nate, didodecylmercaptoethyl-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-4-hy-droxybenzyl)-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)phenol.

1.10. Triazine compounds, 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-hydroxy-anilino)-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-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris-9 220~ 0'-)~

(3,5-di-tert-butyl-4-hydroxybenzyl)isoeyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-di-methylbenzyl)isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-tri-azine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexahydro-1,3,5-triazine, 1,3 ,5-tris(3 ,5 -dicyelohexyl-4-hydroxybenzyl)isoeyanurate.

1.11. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphos-phonate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioetadeeyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioetadecyl-5-tert-butyl-4-hydroxy-3-methylbenzyl-phosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzyl-phosphonic aeid.

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

1.13. Esters of ~-(3,5-di-tert-butyl-4-hydroxyphenyl)propionie acid with mono- or poly-hydric alcohols, e.g. with methanol, ethanol, n-octanolj i-octanol, octadecanol, 1,6-hexane-diol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glyeol, pentaerythritol, tris(hydroxyethyl) isocyanu-rate, N,N'-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 ~-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, l,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodi-ethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundeeanol, 3-thiapentadeeanol, tri-methylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo-[2.2.2]octane.

1. lS. Esters of ~-~3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or poly-hydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, di-ethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, tri-methylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

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1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonane-diol, 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, tri-methylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17. Amides of ~-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, e.g. N,N'-bis(3,5-di-tert-butyl4-hydroxyphenylpropionyl)hexamethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)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-phenylene-diamine, 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' -phenyl-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-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-l-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, for example p,p'-di-tert-octyldiphenylamine, 4-n-butylaminophenol, 4-butyrylaminophe-nol, 4-nonanoylamino-phenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol,bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4'-di-aminodiphenylmethane, 4,4'-diaminodiphenylmethane, N,N,N',N'-tetramethyl-4,4'-di-aminodiphenylmethane, 1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)pro-pane, (o-tolyl)biguanide, bis[4-(1 ',3'-dimethylbutyl)phenyl]amine, tert-octylated N-phe-nyl-l-naphthylamine, a mixture of mono- and dialkylated tert-butyl/tert-octyldiphenyl-amines, a mixture of mono- and dialkylated nonyldiphenylamines, a mixture of mono- and dialkylated dodecyldiphenylamines, a mixture of mono- and dialkylated isopropyl/isohex-yldiphenylamines, a mixture of mono- und dialkylated tert-butyldiphenylamines, 2,3-di-hydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, a mixture of mono- und dialky-~ 2 (~ 1 3 ;~ 3 lated tert-butyl/tert-octylphenothiazines, a mixture of mono- und dialkylated tert-octyl-phenothiazines, N-allylphenothiazine, N,N,N',N'-tetraphenyl-1,4-diaminobut-2-ene, N,N-bis(2,2,6,6-tetramethyl-piperid-4-yl-hexamethylenediamine, bis(2,2,6,6-tetramethylpipe-rid-4-yl)sebacate, 2,2,6,6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.

2. UV absorbers and li~ht 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-(S'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-(1,1,3,3-tetramethylbutyl)phenyl)benzo-triazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-S-chlorobenzotriazole, 2-(3'-tert-butyl--2'-hydroxy-S'-methylphenyl)-S-chlorobenzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(3',5'-bis-(a,a-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole, mixture of 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycar-bonylethyl)phenyl)-S-chlorobenzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)-car-bonylethyl]-2'-hydroxyphenyl)-S-chlorobenzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyl-oxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonyl-ethyl]-2'-hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-S'-methylphenyl)benzo-triazole, and 2-(3'-tert-butyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzotri-azole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylphenol]; the transesterification product of 2-[3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxy-phenyl]-2H-benzotriazole with polyethylene glycol 300; [R-CH2CH2-COO(CH2)3~, where R = 3'-tert-butyl-4'-hydroxy-5'-2H-benzotriazol-2-ylphenyl.

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

2.3. Esters of substituted and unsubstituted benzoic acids, for example 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis(4-tert-butyl-benzoyl) 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, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxy--12- ~23 ~ Oq~

benzoate.

2.4. Acrylates, for example ethyl a-cyano-,~"B-diphenylacrylate, isooctyl o~-cyano-~"~-di-phenylacrylate, methyl oc-carbomethoxycinn~m~t~, methyl ol-cyano-~-methyl-p-methoxy-cinn~m~te, butyl oc-cyano-~-methyl-p-methoxy-cinn~mate, methyl ~c-carbomethoxy-p-methoxycinn~m~te and N-(,~-carbomethoxy-~-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis-[4-(1,1,3,3-tetra-methylbutyl)phenol], such as the 1:1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldi-thiocarbamate, nickel salts of the monoalkyl esters, e.g. the methyl or ethyl 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.

2.6. Sterically hindered amines, for example bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)succinate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)seba-cate, 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-butyl-4-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-octyl-amino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)- 1,2,3 ,4-butanetetracarboxylate, 1,1 ' -(1 ,2-ethane-diyl)-bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(l,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triaza-spiro[4.5]decane-2,4-dione, 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-tetra-methyl-4-piperidyl)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 )-1,3,5-tri-azine and 1,2-bis(3-aminopropylamino)ethane, the condensate of 2-chloro-4,6-bis(4-n-butylamino- 1 ,2,2,6,6-pentamethylpiperidyl)- 1,3 ,5-triazine and 1 ,2-bis-(3 -aminopropyl-amino)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)pyrrolidine-2,5-dione, 3-dodecyl-1-( I ,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy-and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensation product of N,N'-bis-~ 2 2 ~

(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-di-chloro- 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-tetrarnethylpiperidine (CAS
Reg. No. [136504-96-6]); 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-tetra-methyl-l-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9-tetra-methyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro [4,5]decane und epichlorohydrin.
.
2.7. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioc-tyloxy-5,5'-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'-ethox-anilide and the mixture thereof with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide and mixtures of ortho- and para-methoxy-disubstituted oxanilides and rnixtures of o- and p-ethoxy-disubstituted oxanilides.

2.8. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxy-phenyl)-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-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxy-phenyl)-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-pro-poxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyl-oxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[4-(dodecyloxy/tridecyl-oxy-2-hydroxypropoxy)-2-hydroxy-phenyl]-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-dimethylphenyl)-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-bu-toxy-2-hydroxy-propoxy)phenyl]-1,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphe-nyl)-6-phenyl- 1 ,3,5-triazine.

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-hydroxyphenyl-propionyl) hydrazine, 3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl di-hydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-di-acetyladipoyl dihydrazide, N,N'-bis(salicyloyl)oxalyl dihydrazide, N,N'-bis(salicyloyl)-~2~l Oi'~

thiopropionyl dihydrazide.

4. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phos-phites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, triocta-decyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phos-phite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, diisodecyl-oxypentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol di-phosphite, bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol tri-phosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphonite, 6-isooctyl-oxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,1 0-tetra-tert-butyl- 1 2-methyldibenzo[d,g]- 1,3 ,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl)methylphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethylphos-phite.

5. Hydroxylamines, for example, N,N-dibenzylhydroxylamine, N,N-diethylhydroxyl-amine, N,N-dioctylhydroxylamine, N,N-dilaurylhydroxylamine, N,N-ditetradecylhy-droxylamine, N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine, N-hexa-decyl-N-octadecylhydroxylamine, N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkyl-hydroxylamine derived from hydrogenated tallow amine.

6. Nitrones, for example N-benzyl-alpha-phenyl-nitrone, N-ethyl-alpha-methyl-nitrone, N-octyl-alpha-heptyl-nitrone, N-lauryl-alpha-undecyl-nitrone, N-tetradecyl-alpha-tride-cyl-nitrone, N-hexadecyl-alpha-pentadecyl-nitrone, N-octadecyl-alpha-heptadecyl-nitrone, N-hexadecyl-alpha-heptadecyl-nitrone, N-ocatadecyl-alpha-pentadecyl-nitrone, N-hepta-decyl-alpha-heptadecyl-nitrone, N-octadecyl-alpha-hexadecyl-nitrone, nitrone derived from N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

7. Thiosyner~ists, for example, dilauryl thiodipropionate or distearyl thiodipropionate.

8. Peroxide scaven~ers, 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, penta-erythritol tetrakis(,~-dodecylmercapto)propionate.

9. Basic co-stabilizers, for example melamine, polyvinylpyrrolidone, dicyandiamide, tri-~ ' 2~20 1 ~

allyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyure-thanes, 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. Nucleatin~; a~ents, 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 reinforcin~ a~ents, for example, calcium carbonate, silicates, glass fibres, glass beads, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, car-bon 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 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 or EP-A-0 591 102 or 3-[4-(2-acet-oxyethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one, 5,7-di-tert-butyl-3-[4-(2-stearoyl-oxyethoxy)phenyl]benzofuran-2-one, 3,3'-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]-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-butylbenzofuran-2-one, 3-(3,5-dimethyl-4-pivalo-yloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one, 3-(3,4-dimethylphenyl)-5,7-di-tert-bu-tyl-benzofuran-2-one, 3-(2,3-dimethylphenyl)-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 addi-tives, preferably phenolic antioxidants, light stabilizers and/or processing stabilizers.

-16- 22~

Particularly preferred additives are phenolic antioxidants (item 1 in the list), sterically hin-dered 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-hydroxyhydrocinn~m~te, neopentanetetrayl tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinammate), di-n-octadecyl 3,5-di-tert-butyl-4-hydroxyben-zylphosphonate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, thiodiethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinn~m~te), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 3,6-dioxaoctamethylene bis(3-methyl-S-tert-butyl-4-hydroxyhydrocinn~m~te), 2,6-di-tert-butyl-p-cresol, 2,2'-ethylidene-bis(4,6-di-tert-butyl-phenol), 1,3,5-tris(2,6-dimethyl-4-tert-butyl-3-hydroxybenzyl)isocynurate, 1,1,3-tris(2-methyl-4-hydroxy-S-tert-butylphenyl)butane, 1,3,5-tris[2-(3,5-di-tert-butyl-4-hydroxy-hydrocinnamoyloxy)ethyl]isocyanurate, 3,5-di-(3,5-di-tert-butyl-4-hydroxybenzyl)mesitol, hexamethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinn~m~t( ), 1-(3,5-di-tert-butyl-4-hydroxyanilino)-3,5-di(octylthio)-s-triazine, N,N'-hexamethylene-bis(3,5-di-tert-butyl-4-hydroxyhydrocinn~m~mide), calcium bis(ethyl 3,5-di-tert-butyl-4-hydroxybenzylphospho-nate), ethylene bis[3,3-di(3-tert-butyl-4-hydroxyphenyl)butyrate], octyl 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hy-drazide, and N,N'-bis~2-(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyloxy)-ethyl]-oxamide.

A most preferred phenolic antioxidant is neopentanetetrayl tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinn~m~te), n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinn~m~te, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 2,6-di-tert-butyl-p-cresol or 2,2'-ethylidene-bis(4,6-di-tert-butylphenol) .

The trialkanolamine trisphosphites of the formula I of component (b) protect phenolic antioxidants used in polyolefins containing catalyst residue, especially aluminum residues, 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-4-yl) sebacate, di(1,2,2,6,6-pentamethylpiperidin-4-yl) (3,5-di-tert-butyl-4-hydroxybenzyl)-butylmalonate, 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethyl-piperidine, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triaza-spiro[4.5]decane-2,4-dione, ~ ~a~

tris(2,2,6,6-tetramethylpiperidin-4-yl) nitrilotriacetate, 1,2-bis(2,2,6,6-tetramethyl-3-oxo-piperazin-4-yl)ethane, 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxodispirot5.1.11.2] hen-eicosane, polycondensation product of 2,4-dichloro-6-tert-octylamino-s-triazine and 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine), polycondensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, polyconden-sation product of 4,4' -hexamethylenebis-(amino-2,2,6,6-tetramethylpiperidine) and 1,2-di-bromoethane, tetrakis(2,2,6,6-tetramethylpiperidin-4-yl) 1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethylpiperidin-4-yl) 1,2,3,4-butanetetracarboxylate, polyconden-sation product of 2,4-dichloro-6-morpholino-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-s-triazin-2-yl]- 1,10-diamino-4,7-diaza decane, mixed [2,2,6,6-tetra-methylpiperidin-4-yl/~"~,~' "~'-tetramethyl-3,9-(2,4,8,10-tetraoxaspiro[5.5]-undecane) di-ethyl] 1,2,3,4-butanetetracarboxylate, mixed [1,2,2,6,6-pentamethylpiperidin-4-yl/,B,~,~3'"~'-tetramethyl-3,9-(2,4,8,10-tetraoxaspiro[5.5]undecane)diethyl] 1,2,3,4-butanetetracarboxylate, 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-tetra-methylpiperidin-4-yl) sebacate.

A most preferred hindered amine compound is bis(2,2,6,6-tetramethylpiperidin-4-yl) seba-cate, the polycondensation product of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxy-piperidine and succinic acid, the polycondensation product of 2,4-dichloro-6-tert-octyl-amino-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)-s-triazine-2-yl]- 1,10-diamino-4,7-~i~7~1.Dc~ne or bis(1 -octyloxy-2,2,6,6-tetramethylpiperidin-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 ~ 2 ~ 3 ~

R~15 R 14 ~ ~

R' ~ c/
R.l2 H R~
wherein R' 1 l is an unsubstituted or substituted carbocyclic or heterocyclic aromatic ring system;
R'l2 is hydrogen;
R' 14 is hydrogen, alkyl of 1 to 12 carbon atoms, cyclopentyl, cyclohexyl or chloro;

R' 13 has the meamng of R' 12 or R' 14 or is a radical of formula -(CH23~C-OR' 16 -(CH2~C-N(R'17)2, ~cH2~c-o-A-o-c~cH2 S~E, O O O O
Il 11 11 11 (CH2)s-C-NR l8-A-NR' 18-c-(cH2)s-E ~ --(cH2)s-c-NR7 l8-A-O-C-(CH2)s-E, (CH2~C--N N--C~cH2~E~-cH2-s-R 19~ -CH(C6H5)-C-OR 16 or-D-E, wherein R'l6 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;
sisO, 1 or2;
substituents R' 17 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 -C2H40H, -C2H4-O-CtH2t+l or -C2H4-O-C-R'2o, or, together with the linking nitrogen atom, form a piperidine or morpholine radical;
tis 1 to 18;
R'20 is hydrogen, alkyl of 1 to 22 carbon atoms, or cycloalkyl of 5 to 12 carbon atoms;

- 19 - 2 ~ 0 9 3 A is alkylene of 2 to 22 carbon atoms which may be interrupted by nitrogen, oxygen or sulfur;
R'l8 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'lg is alkyl of 1 to 18 carbon atoms;
D is -O-, -S-, -SO-, -SO2- or -C(R'2l)2-;
substituents R'2l are each independently of one another hydrogen, Cl-Cl6alkyl, the two R'2l radicals together containing 1 to 16 carbon atoms, and R'2l is furthermore phenyl or a O O
radical of formula ~CH23~C-OR' 16 or ~CH2~-N(R' 17)2 , wherein s, R' 16 and R' 17 are as defined above;
E is a radical of formula ,~c/c=o~

R'12 H R

wherein R'll, R'l2 and R'l4 are as defined above; and R'l5 is hydrogen, alkyl of 1 to 20 carbon atoms, cyclopentyl, cyclohexyl, chloro, or a O O
radical of formula -CH2-C-OR'I6 or -CH2-C-N(R'I7)2, wherein R'l6 and R'l7 are asdefined above, or R' 1S and R' 14, taken together, form a tetramethylene 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 tCH2 s~C-OR' 16 ~

~CH23 S--C-N(R' 17)2 or -D-E, wherein s, R' 16, R' 17~ D and E are as defined above, and R' 16 is preferably hydrogen, alkyl of 1 to 18 carbon atoms, cyclopentyl or cyclohexyl.

--20- ~a~o~

Preferred benzofuran-2-ones are also those wherein R' 1 l is phenyl or phenyl which is substituted by 1 or 2 alkyl radicals having a total of at most 12 carbon atoms; R'12 is hydrogen; R'l4 is hydrogen or alkyl of 1 to 12 carbon atoms; R'l3 is hydrogen, alkyl of 1 O O
to 12 carbon atoms, ~CH2~C-OR 16, ~cH23~c-N(R 17)2 or -D-E; R IS is C) O
hydrogen, alkyl of 1 to 20 carbon atoms, -CH2-C-OR' 16 or -CH2-C-N(R' 1?)2, or R' 15 and R' 14~ 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 1~' 13 is hydrogen, alkyl of 1 to 12 carbon atoms or -D-E; R' 12 and R' 14 are each independently of the other hydrogen or alkyl of 1 to 4 carbon atoms; R' l5 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 R' 13 is alkyl of 1 to 4 carbon atoms or -D-E; R' 12 and R' 14 are hydrogen; R' IS is alkyl of 1 to 4 carbon atoms, cyclopentyl or cyclohexyl, D is a -C(R'21)2- group, and E is a radical of formula /~ ' R 12 R~11 the substituents R'2l being identical or different and are each alkyl of 1 to 4 carbon atoms, and R 11, R 12, R 14 and R'1s 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 O.OOOS 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, com-~ ~ 2 ~ t oi-~

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, ther-mal and/or 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, which process comprises incorporating therein or applying thereto a compound of the for-mula I according to component (b).

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

Example l: Stabilization of polypropylene.

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

Into 1000 grams of Himont Profax~ 6501 (bulk phase polymerization) polypropylenepowder 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 1 12 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 ex-truded 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 274~C. 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, re-tains 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 ~ ~ O ~ 3 Tinius-Olsen extrusion plastometer filled with a 2.16 kg weight at 230~C. Yellowness in-dex is measured using ASTM method 1925-90 on an Applied Color Systems Spectropho-tometer with the large area view orifice, spectral component included, C illuminant, 2~ ob-serve on 3.175 mm compression molded plaques.

Polymer: Himont Profax(~) 6501 polypropylene, Ti/AI catalyst; Spheripol Process; Nomi-nal melt index = 5.3 dg/min at 2.16 kg/230~C. Extrusion Conditions: Zone 1 at 246~C.
Zone 2 at 260~C. Zone 3 at 274~C. Zone 4 at 274~C. Extruded with hopper open to air at 90 rpm. Residence time approximately 1 minute in barrel. Extruder: Superior MPM
2.54 cm; 241 l/d. Screen pack: 20-60-100-60-20. Screw Design: polyolefin screw with Maddock Mixing Head. Compression Molding: 232~C, 3 minutes low pressure, 3 minutes high pressure, 3 minutes cooling.

Example 1 illustrates the prevention of color formation from the 1st to the 5th pass in po-lypropylene compositions containing 750 ppm of neopentanetetrayl tetrakis(3,5-di-tert-bu-tyl-4-hydroxyhydrocinn~m~te), 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, Al-A3 are each ethylene, Yl-Y6 and Zl-z6 are each tert-butyl, Irgafos(~) 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 l below for each level of residual aluminum in the composition. Iower YI values indicate less discoloration.

~ 22 ~ ~ 09~

Table 1:
Compound of the Triethyl Aluminum Yellowness Index formula I
(ppm) (ppm) [ppm as Al]1st 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 50 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 Irgafos(~) 12 (Ciba Specialty Chemicals) is a compound of the formula Ia ~ C
H3C--C ~ \CH3 CCH3 P ~ CH2--CH2 N(Ia) H3C--C ~0 CH3 ~ CH3 H3C ~ \CH

Example 2: Stabilization of polypropylene.

When 750 ppm of Irganox(~) 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 I, see example 1) is seen on preventing discolora-tion in the polypropylene containing various levels of aluminum residues as seen in the table 2 below.

-24- 22~1 ~9~

Table 2:
Compound of the Triethyl Alulnil-u--l Yellowness Index formula I
(ppm) (ppm) [ppm as Al] 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 trialkylalumi-num compound. All manipulations with Trialkylaluminum are carried out in a dry box un-der an argon atmosphere with the rigorous exclusion of moisture.

To a solution of 2 grams (1.37 mmol) of Irgafos~ 12 in 4 ml of chloroform is added 1.37 ml (1.37 mmol) of a 1 molar hexane solution of triethylaluminum. The 3IP{lH} nmr spectrum shows resonances at ~ 132.8 ppm and 32.7 ppm whereas uncomplexed Irgafos 12 has a singlet resonance at ~ 137.1 ppm.

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

The procedure of Example 3 is repeated with 0.88 g (1.37 mmol) of tris(2,4-di-tert-butyl-phenyl) phosphite, Irgafox(~) 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 nmr data.

Claims (12)

1. A composition comprising a) a polyolefin subject to oxidative, thermal and/or 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 acatalyst or cocatalyst to effect polymerization of said polyolefin, and b) an effective stabilizing amount of a compound of the formula I

(I) wherein n is 0 or 1, when n is 0, Q is a direct bond, or when n is 1, Q is -S- or -CR1R2- wherein R1 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 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 E1E2E3Si where E1, E2and E3 are independently hydrogen, alkyl of 1 to 4 carbon atoms or phenyl, and A1, 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.

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, Y5, Y6, Z1, Z2, Z3, Z4, Z5 and Z6 are each tert-butyl, and A1, 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, Z1, Z2, Z3, Z4, Z5 and Z6 are each tert-butyl, and A1, A2 and A3 are each ethylene.

4. A composition according to claim 1 wherein the catalyst residue contains aluminum, boron, titanium, zirconium, chromium, vanadium or mixtures thereof.

5. A composition according to claim 1 wherein the catalyst residue contains aluminum.

6. A composition according to claim 1 wherein the polyolefin is a homopolymer orcopolymer of propylene or ethylene.

7. A composition according to claim 1 wherein the polyolefin is polypropylene orpolyethylene.

8. A composition according to claim 1 wherein the polyolefin has not undergone adeashing or related step to reduce the catalyst residue content.

9. A composition according to claim 1 which contains component (b) in an amount of 0.01 to 5 %, based on the weight of component (a).

10. A composition according to claim 1 which additionally contains a phenolic antioxidant, a light stabilizer and/or a processing stabilizer.

11. A composition according to claim 1 which additionally contains as a coadditive at least one compound of the benzofuran-2-one type.

12. A process for stabilizing a polyolefin against oxidative, thermal and/or 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, which process comprises incorporating therein or applying thereto a compound of the formula I according to component (b) of claim 1.