MXPA00002136A

MXPA00002136A - Stabilizer combination for the rotomolding process

Info

Publication number: MXPA00002136A
Application number: MXPA/A/2000/002136A
Authority: MX
Inventors: Leo Stadler Urs
Original assignee: Ciba Specialty Chemicals Corporation
Priority date: 1999-03-01
Filing date: 2000-03-01
Publication date: 2002-05-09

Abstract

A process for the production of polyolefin hollow articles comprises charging the polyolefin with a stabilizer combination comprising (a) at least one compound from the group of the organic phosphates or phosphonites, (b) one or more compounds selected from the group consisting of i.) hydroxylamine derivatives and ii.) amine oxide derivatives and c) at least one compound from the group of the hindered amine stabilizers, filling this mixture into a mould, heating this mould in an oven to above 280ºC, such that the stabilized polyolefin fuses, rotating the mould around at least 2 axes, the plastic spreading to the walls, and cooling the mould while still rotating, opening it and taking the resultant hollow article out.

Description

STABILIZING COMBINATION FOR THE RTTOMOLDEO PROCESS The present invention relates to the production of hollow polyolefin articles by the rotomolding process, and to the stabilizing combination of the used processing described below. Rotomolding, or rotational molding / casting process, is used for the production of hollow articles of plastic material, rather large, which can be reinforced with glass fibers (Encyclopedia of Polymer Science and Engineering, Wiley Interscience 1988, Vol 14, pp. 659-670). In principle, this process is carried out as follows: the plastic material is introduced into one of the molding halves, filling it; next, this half is closed together with the other half, and the assembly is heated in an oven in such a way that the molten plastic material is distributed over the walls of the mold when it is rotated around various axes. After cooling, the hollow article is obtained. In this way it is possible to obtain, for example, storage tanks or reservoirs and tanks for trucks, from high density polyethylene. Normally the process requires temperatures in the range above 300 ° C, sometimes even higher than 400 ° C. Therefore, the requirements to be met by the stabilizers are different and even more severe than those corresponding to for example the process Extrusion in which the temperatures are usually not much higher than 280 ° C. The combined use of phosphite stabilizers or phosphonites together with sterically hindered phenols and / or sterically hindered amines (HALS) in polyolefins, is known (see, e. , R. Gáchter, H. Müller, "Plastic Additives Handbook", Hanser Publishers, pp. 40-71 (1990)).

Hydroxylamine derivatives, such as N, N-dialkyl hydroxylamines and N, N-dibenzyl hydroxylamines, are well known as useful stabilizers for a variety of polymeric substrates, as taught for example in U.S. Patent Nos. 4,590,231, 4,668,721, 4,782,105 and 4,876,300, the relevant parts of which are incorporated herein, by way of reference. In US Patent Nos. 4,649,221, 4,691, 015 and 4,703,073 the use of polyhydroxylamine compounds derived from hindered amines and alkylated N, N-dibenzyl hydroxylamine, respectively, together with one more compound selected from the group consisting of; phenolic antioxidants, hindered amine light stabilizers, hydroxybenzoate alkyd light stabilizers, ultraviolet light absorbers, organic phosphorus compounds, alkali metal salts of fatty acids and thiosinérgidos, with a view to the stabilization of polyolefins. In U.S. Patent No. 4,782,105 the use of Long chain N-dialkylhydroxy amines for the stabilization of poly (arylene sulphides) and unsaturated elastomers. Examples are shown in which the long chain N.sub.N-dialkyl hydroxylamines are used together with phosphite stabilizers in a styrene / butadiene copolymer. In U.S. Patent No. 4,876,300 the use of Long chain N-dialkylhydroxy amines as process stabilizers for polyolefin compositions. Examples are shown in which the long chain N.sub.N-dialkyl hydroxylamines are used together with phosphite stabilizers and also in those which are used together with hindered amine stabilizers.

US Pat. Nos. 4,590,231 and 4,668,721 disclose the use of N, N-dibenzylhydroxyl amines or other hydroxylamine derivatives together with metal salts of fatty acids and phenolic antioxidants for the stabilization of polyolefin compositions. The compositions may also contain organic phosphorus compounds or hindered amine stabilizers. In U.S. Patent No. 5, 013,510 a process for the preparation of long chain N.N-dialkylhydroxy amines by direct oxidation is taught. It is mentioned that the long chain N.sub.N-dialkyl hydroxylamines are effective to achieve the stabilization of the polyolefin compositions. In US Pat. No. 5,596,033 the stabilization of polypropylene fibers with a binary system of selected hindered amines is revealed, obtaining the N-dialkyl hydroxylamine by direct oxidation of N, N-di (hydrogenated tallow) amine. US Pat. No. 5,149,774 discloses the use of hydroxylamine derivatives to reduce color formation during the recycling of already discolored polyolefin resins. In US Patent Nos. 5,844,029 and 5,880,191 the use of amine oxides of saturated hydrocarbons is disclosed for the stabilization of thermoplastic resins. It is disclosed that the thermoplastic compositions may further contain a stabilizer, or a mixture of stabilizers, selected from the group consisting of; phenolic antioxidants, hindered amine light stabilizers, ultraviolet light absorbers, organic phosphorus compounds, alkali metal salts of fatty acids and thiosincerids. The joint use of amine oxides with other stabilizers with a view to the stabilization of polyolefins is not exemplified. Now, it has been discovered that the combination of hydroxyl amines derivatives, together with organic phosphites or phosphonites and hindered amine stabilizers, results in excellent stabilization in the rotomolding process. By virtue of the above, the present invention relates to a novel process for the production of hollow polyolefin articles, this process comprising introducing into the polyolefin a charge consisting of a stabilizing combination, which combination comprises: a. minus one compound selected from the group consisting of: phosphites and phosphonites, orgone; b.- one or more compounds selected from the group consisting of; i.- hydroxylamine derivatives, and ii.- amine oxide derivatives, and c- at least one compound selected from the group consisting of: hindered amines stabilizers, filling a mold with this mixture, heating this mold in an oven at a temperature of more than 280 ° C in such a way that the polyolefin, stabilized, flows, to rotate the mold around at least two axes, distributing the plastic material on the walls, cooling the mold while it is still rotating, opening it, and extracting the resulting hollow article.

Of interest is a novel process in which the component a.- is at least one compound selected from the following formulas (1), (2), (3), (4), (5), (6) and (7): (2) (7) in which the sub-indices are integers, and n is 2, 3 or 4; p is 1 or 2; q is 2 or 3; r is worth 4 to 12; and is worth 1, 2 or 3; and z is from 1 to 6; A-i, if f n is 2, represents C2-C18 alkylene; C2-C? 2 alkylene interrupted by or Ai, if n is 3, represents a radical of the formula -CrH2r -? -; A-i, if n is 4, represents CH, - I 2 -CH, - C - CH 2 - CH, - A2 is as defined for Ai if n is 2; B is a direct bond, -CH2-, -CHR4-, -CR? R4-, sulfur, C5-C7 cycloalkylidene, or cyclohexylidene which is substituted by from 1 to 4 alkyl radicals of 1 to 4 carbon atoms in the 3-position , 4 and / or 5; D-i, if p is 1., represents alkyl of 1 to 4 carbon atoms and, if p = 2, represents -CH2OCH2-; D2, if p = 1, represents alkyl of 1 to 4 carbon atoms; E, if y = 1, represents alkyl of 1 to 18 carbon atoms, -ORÍ or halogen; E, if y = 2, represents -O-A2-O-, E, if y = 3, is a radical of the formula R4C (CH2O-) 3 or N (CH2CH2O-) 3; Q is the radical of at least z-valent alcohol or phenol, said radical being linked by the oxygen atom to the phosphorus atom; R? > R2 and 3 independently from each other represent alkyl of 1 to 18 carbon atoms which is unsubstituted or substituted by halogen, -COOR4, -CN or-CONR4R4; alkyl of 2 to 18 carbon atoms interrupted by oxygen, sulfur or -NR4-; C7-C9 phenyl alkyl, C5-C? 2 cycloalkyl, phenyl or rtafilo; naphthyl or phenyl substituted by halogen, having from 1 to 3 alkyl or alkoxy radicals a total of 1 to 18 carbon atoms or by C7-C9 phenyl alkyl; or a radical of the Formula - (CH2) -? - OH in which m is an integer in the range of 3 to 6; R is hydrogen, C1-C18 alkyl, Cs-C? 2 cycloalkyl or C7-C9 phenylalkyl, R5 and R6 independently from each other, represent hydrogen, C? -C8 alkyl or C5-C6 cycloalkyl, R7 and Rs, if q = 2 , independently of one another, represent C1-C4 alkyl or together form a 2,3-hydroquinone pentamethylene radical; and R7 and R8, if q = 3, represent methyl; Ru is hydrogen, C 1 -C 9 alkyl or cyclohexyl, R 15 is hydrogen or methyl and, if there are two or more radicals R 14 and R 15 present, these radicals are identical or different, X and Y, are each a direct bond or oxygen; Z is a direct bond, methylene, -C (Ri 6h- or sulfur, and R is Ci-Cβ alkyl) C 2 -C β alkylene is a straight or branched radical, for example ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene , heptamethylene, octamethylene, decamethylene, dodecamethylene or octadecamethylene Preference is given to C 2 -C 2 alkylene, especially C 2 -C 8 alkylene. __i-_-_ iiajilt_i¿fcÉJ_J__JJ1-, _ - nti? itrtr C2-C? s alkylene interrupted by oxygen, sulfur or -NR4- is, for example "-CH2-O-CH2-, -CH2-S-CH2- , -CH2-NH-CH2-, -CH2-N (CH3) -CH2-, -CH2-O-CH2CH2-O-CH2-, -CH2- (O-CH2CH2-) 2O-CH2-, -CH2- ( O-CH2CH2-) 30-CH2-, -CH2- (O-CH2CH2-) 4O-CH2- or -CH2CH2-S-CH2CH2-. A C5-C7 cycloalkylidene alkyl ring of 1 to 4 carbon atoms-substituted, which preferably it contains from 1 to 3, in particular 1 or 2 linear or branched alkyl radicals, it can be for example cyclopentylidene, methylcyclopentylidene, dimethyl cyclopentylidene, cyclohexylidene, methylcyclohexylidene, dimethylcyclohexylidene, trimethylcyclohexylidene, tert-butyl cyclohexylidene or cycloheptylidene. Preference is given to cyclohexylidene and tert-butylcyclohexylidene Alkyl having up to 18 carbon atoms is a straight or branched radical, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, -ethylbutyl, n-pentyl, isopentyl, 1-me tilpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methyl hexyl, n-heptyl, isoheptyl, 1,1-tetramethyl butyl, 1-methylheptyl, 3-methyl heptyl, n-octyl, 2-ethylhexyl , 1, 1, 3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1, 1, 3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl , hexadecyl, heptadecyl or octadecyl. Halogen (halo) is, for example, chlorine, bromine, or iodine. Chlorine is preferred.

C2-C? S alkyl interrupted by oxygen, sulfur or -NR4- is, preferably, CH3-O-CH2-, CH3-S-CH2-, CH3-NH-CH2-, CH3-N (CH3) -CH2-, CH3-O-CH2CH2-O-CH2-, CH3- (O-CH2CH2-) 2O-CH2-, CH3- (O-CH2CH2-) 3O-CH2- or CH3- (O-CH2CH2-) 4O-CH2-.

C7-Cg phenylalkyl is, for example, benzyl, α-methylbenzyl, α, α-dimethylbenzyl or 2-phenyl ethyl. Benzyl and α, α-dimethylbenzyl are preferred. Alkyl cycle of 5 to 12 carbon atoms, substituted or not by alkyl of 1 to 4 carbon atoms, is for example: cyclopentyl, methyl cyclopentyl, dimethyl cyclopentyl. cyclohexyl, methyl hexyl, dimethyl cyclohexyl, trimethyl cyclohexyl, tert-butyl cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl or cyclododecyl. The hexyl cycle and the tert-butyl cyclohexyl are preferred. Alkoxy having up to 18 carbon atoms is a straight or branched radical, for example methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy, tetra decyloxy, hexadecyloxy or octadecyloxy. Preference is given to alkoxy having from 1 to 12, in particular from 1 to 8, for example from 1 to 6 carbon atoms. Of particular interest is a novel process in which component (a) is at least one compound selected from formulas (1), (2), (5) and (6), in which n = 2, e and is worth 1, 2 or 3; Ai is C2-C? Alkylene, p-phenylene or p-biphenylene, E, if y = 1, represents C? -C? 8 alkyl, -ORi or fluoro; E, if y is 2, is p-biphenylene, E, if y is 3, is N (CH 2 CH 2 O-) 3, Ri, R 2 and R 3 independently of each other are C 1 -C 18 alkyl, C 7 -C 9 phenyl alkyl, cyclohexyl, phenyl, or phenyl substituted by from 1 to 3 alkyl radicals having a total of 1 to 18 carbon atom; R14 is hydrogen or C1-C9 alkyl, R-I5 is hydrogen or methyl; X is a direct bond, Y is oxygen, Z is a direct bond or -CH (R? 6) -, and R ^ is C1-C4 alkyl. Also of interest is a novel process in which component (a) is at least one compound selected from formulas (1), (2), (5) and (6), in which: N = 2, e and is worth 1 or 3; Ai is p-biphenylene, E, if y is 1, is C1-C18 alkoxy or fluorine, E, if y is 3, is N (CH 2 CH 2 O-) 3, R 1, R 2 and R 3 independently of each other, represent C 1 -C 18 alkyl, or phenyl substituted by 2 or 3 radicals having a total of 2 to 12 carbon atoms; R 14 is methyl or tert-butyl; R15 is hydrogen; X is a direct link; And it's oxygen; and Z is a direct bond, methylene or -CH (CH 3) -. Particular preference is given to a process in which component (a) is at least one compound selected from formulas (1), (2) and (6) - Particular preference is given to a process in which the component (a) is at least one compound selected from formula (I): wherein: R17 and R • independently of each other, represent hydrogen, C Cß alkyl, cyclohexyl or phenyl, and R 19 and R 2o, independently of one another, represent hydrogen or C 1 -C 4 alkyl. The following compounds are examples of organic phosphites and phosphonites which are particularly suitable for use in component (a) in the novel process: Triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris (nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite , distearil pentaerythritol diphosphite, tris (2,4-di-tert-butylphenyl) phosphite (lrgafos®168, Ciba Specialty Chemicals Corp.), diyl penta erythritol diphosphite, bis (2,4-di-tert-butylphenyl) penta erythritol diphosphite (for mu (D)), bis (2,6-di-tert-butyl-4-methylphenyl) penta erythritol diphosphite (formula (E)), bis-isodecyloxy-penta erythritol diphosphite, bis (2,4-di- tert-butyl-6-methylphenyl) penta erythritol diphosphite, bis (2,4,6-tri-tert-butylphenyl) penta erythritol diphosphite, tristearyl sorbitol tri-phosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4 '-biphenylene-diphosphonite (lrgafos® P-EPQ, Ciba Specialty Chemicals Corp., formula (H)), 6-isooctyloxy-2,4,8, 10-tetra-tert-butyl-dibenzo [d, f] [1 , 3,2] dioxaphosphepin (formula (C)), 6-fluor-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo [d, g] [1,2] dioxaphosphocin (formula (A)), bis (2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite (formula (G)).

With a particular preference the following phosphites and phosphonites are used in component (a) in the novel process: Tris (2,4-di-tert-butylphenyl) phosphite (Irgafos® 168, Ciba Specialty Chemicals Corp.), tris - ( nonylphenyl) phosphite, ( * ítÉt? títM? To tmi ^ ^? m? ttmít ^ tu ^^^ it á mß A very special preference is given to the use of the following compounds in component (a) in the novel process: Tris (2,4-di-tert-butylphenyl) phosphite (lrgafos®168, Ciba Specialty Chemicals Corp.), bis (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite (lrgafos®38, Ciba Specialty Chemicals Corp., formula (G)), bis (2,4-di-tert-butylphenyl) penta erythritol diphosphite ( Ultranox® 626, GE Chemicals, formula (D)), tetrakis (2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphonite (Irgafos®P-EPQ, Ciba Specialty Chemicals Corp., formula (H) ), 2,2 ', 2"-nitrile [triethyltris (3,3'5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl) phosphite ] (Irgafos® 12, Ciba Specialty Chemicals Corp., formula (B)), Ultranox®641 (GE Chemicals, formula (J)), Doverfos® S9228 (Dover Chemicals, formula (K)) or Mark® HP10 (Adeka Argus , formula (L)) These organic phosphites and phosphonites are known compounds: many of them can be obtained commercially. (a) are preferably used in amounts from about 0.01% to about 10%, in particular from about 0.05% to about 5%, typically from 0.1% to about 3% by weight, based on the weight of the hollow article of polyolefin to be stabilized. The hydroxyl amine derivatives of component i) used in the novel process are of the following formula (II): wherein Ti is linear or branched alkyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, or said aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms carbon or by one or two halogen atoms: T2 is hydrogen, or independently has the same meaning as Ti. Alkyl having up to 36 carbon atoms is a straight or branched radical, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, -methylpentyl, 1,3-dimethyl butyl, n-hexyl, 1-methyl hexyl, n-heptyl, isoheptyl, 1,1-tetra-methylbutyl, 1-methylheptyl, 3-methyl heptyl, n-octyl, 2 -ethylhexyl, 1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methyl undecyl, dodecyl, 1,1, 3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl or octa decyl. Cd-C? 2b cycloalkyl is, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl or cyclododecyl. Preference is given to cyclohexyl. C 7 -C 9 aralkyl is, for example, benzyl, α-methylbenzyl, α.a-fimethylbenzyl or 2-phenylethyl. Benzyl and α, α-di-methylbenzyl are preferred. Halogen (halo) is, for example, chlorine, bromine or iodine, with chlorine being preferred. Preference is given to a process in which the compounds of component (i) are N, N-dihydrocarbylhydroxyl amines of the Formula (II) in which Ti and T2 are independently benzyl, ethyl, octyl, lauryl, dodecyl, tetradecyl, hexadecyl, heptadecyl or octadecyl, or in which Ti and T2 are, each of them, the alkyl mixture found in hydrogenated tallow amine.

Particular preference is given to a process in which the compounds of component (i) are: N, N-dihydrocarbyl hydroxylamines selected from the group consisting of; N, N-dibenzylhydroxyl amine, N, N-diethylhydroxyl amine, N, N-dioctyl hydroxylamine, N, N-dilaurylhydroxylamine, N, N-didodecyl hydroxylamine, N, N-ditetradecylhydroxylamine, N, N-dihexadecyl hydroxylamine, NN-dioctadecyl hydroxyl amine, N-hexadecyl-N-tetradecyl hydroxylamine, N-hexadecyl-N-heptadecyl. hydroxyl amine, N-hexadecyl-N-octadecyl hydroxylamine, N-heptadecyl-N-octadecyl hydroxyl amine, and N, N-di (tallow hydrogenated) hydroxylamine. Particular preference is given to a process in which component (i) is an N, N-di (alkyl) hydroxyl amines produced by the direct oxidation of N, N-di (hydrogenated tallow) amine (Irgastab® 042, Ciba Specialty Chemicals Corp.). The amine oxide derivatives of component ii) are saturated tertiary amine oxides represented by the following general formula (III) OR .N (III) G: G wherein: Gi and G2 are independently from each other a linear or branched alkyl of 6 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkaryl of 7 to 36 carbon atoms , cycloalkyl of 5 to 36 carbon atoms, alkyl cycloalkyl of 6 to 36 carbon atoms or alkylalkyl cycle of 6 to 36 carbon atoms. - '- • * • * > - • "* - * G3 is a linear or branched alkyl of 1 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36 carbon atoms, alkyl cycloalkyl of 6 to 36 carbon atoms or alkylalkyl cycle of 6 to 36 carbon atoms, with the proviso that at least one of Gi, G2 and G3 contains a carbon-beta-hydrogen bond and wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groups can be interrupted by one to sixteen groups -O-, -S-, -SO-, -SO2-, -COO-, -OCO-, -CO-, -NG-, -CONG4- and -NG CO-, or in which said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkyl alkyl groups can be substituted by one to ten six groups selected from the group consisting of -OG4, -SG4, -COOG4, -OCOG4, -COG4, -N (G) 2, -CON (G4) 2, -NG4COG4 and rings of 5 and 6 members containing the upo -C (CH3) (CH2RX) NL (CH2RX) (CH3) C- or in which said alkyl, aralkyl, alkaryl, cycloalkyl, alk cycloalkyl and cycloalkyl groups are both interrupted and substituted by the aforementioned groups; and wherein G4 is independently hydrogen or alkyl of 1 to 8 carbon atoms; R x is hydrogen or methyl, preferably hydrogen; L is a linear or branched alkyl part of 1 to 30 carbon atoms, a part -C (O) R in which R is a straight or branched chain alkyl group of 1 to 30 carbon atoms, or a part -OR in wherein R is a straight or branched chain alkyl group of 1 to 30 carbon atoms; and wherein said aryl groups can be substituted by one to three halogen atoms, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms or combinations thereof. Aryl of 6 to 12 carbon atoms is, for example, phenyl, naphthyl, thienyl or pyridyl. A preferred structure of Formula (III) is when Gi and G2 are independently benzyl or substituted benzyl. It is also possible that each of the Gi, G2, and G3 are the same radical. Gi and G2 are also preferably alkyl groups of 8 to 26 carbon atoms and more preferably alkyl groups of 10 to 26 carbon atoms and G3 is preferably an alkyl group of 1 to 22 carbon atoms and more preferably methyl or substituted methyl. Also, the substituted amine oxides include those in which Gi, G2, and G3 are the same alkyl groups of 6 to 36 carbon atoms. It is preferable that all of the aforementioned residues for Gi, G2, and G3 are saturated hydrocarbon radicals or saturated hydrocarbon radicals containing at least one of the parts -O-, -S-, -SO-, -CO2-, -CO-, or -CON-, previously mentioned. Those skilled in the art will be able to devise other useful radicals for each of the Gi, G2, and G3, without departing from the present invention. The saturated amine oxides of component ii) may also include poly (amine oxides). By the expression poly (amine oxide), tertiary amine oxides containing at least two tertiary amine oxides per molecule are designated. Illustrative poly (amine oxides), also referred to as "poly (tertiary amine oxides)", include analogs to tertiary amine oxides of aliphatic and alicyclic diamines such as for example 1,4-diamino butane; 1, 6-diamino hexane; 1,10-diaminodecane; and 1, 4-diaminocyclohexane, and aromatic base diamines such as, for example, diamino anthraquinones and diaminoanisoles. Compound (ii) also includes tertiary amine oxides derived from oligomers and polymers of the aforementioned diamines. Useful amine oxides also include amine oxides linked to the polymers, for example polyolefins, polyacrylates, polyesters, polyamides, polystyrenes, and the like. When the amine oxide is linked to a polymer, the numerical amount of amine oxides per polymer can vary widely since it is not necessary that all of the polymer chains contain an amine oxide. All of the aforementioned amine oxides may optionally contain at least a part -O-, -S-, -SO-, -CO2-, -CO-, or -CONG4- In a preferred embodiment, each amine oxide tertiary polymeric amine oxide contains a C1 radical. The groups G1, G2 and G3 of the formula (III) can be attached to a molecule containing a hindered amine. Hindered amines are known in the art and the amine oxide of the present invention can be attached to the hindered amine any way and in any structural position of the hindered amine. Hindered amines, when they are part of a compound of component ii), include those of the general formulas (IV) and (V): wherein L and Rx are as previously described. Also included are amine oxides which contain more than one hindered amine and more than one saturated amine oxide per molecule. The hindered molecule can be linked to a poly (hindered amine oxide) or be attached to a polymeric substrate, as described above. Compounds of component (b) are preferably used in total amounts of from about 0.0005% to about 5%, in particular from about 0.001% to about 2%, typically from about 0.01% to about 2% by weight, based on the weight of the hollow polyolefin article to be stabilized. Component (c) used in the novel process is at least one compound that contains at least one group of Formula (VI): in which Rx is hydrogen or methyl. It is preferable that Rx is hydrogen. It is preferable that the compounds of component (c) are of high molecular weight and can be discrete compounds or oligomeric mixtures. Among the particularly preferred hindered amines of component (c), we have: (H1) Tinuvin " 123 (H2) Tinuvin 144 (H3) Tinuvin 765 (H4) Tinuvin * 622 (H5) Chinnasorb ™ 944 .¡. «« N .- ^^ ***** - * (H7) Sanduvor® PR- 31 (H8) Tinuvin®770 R "R 'I R' - NH - (CH2) 3- N - (CH2) 2- N - (CH2) 3-NH-R '(HTJChimassortT 119 - .-. [- «.. f. ^ F *, ** ^ ***. ^ _. - - **** »* -» Chimassorb®2020 (H10) (H11) (H12) Cyasorb® UV-3346 (H13) Cyasorb® UV-3529 (H14) Hostavin®N30 "- ***** - ^^^. ^ "., ._" _. ^ _._. . "(H16) Uvasil®299 (H17) Uvasorb®HA88 in which: m and n are a number in the range of 2 to 200.

Compositions of the sterically hindered amine type are known, and some of them are commercially available. Tinuvin® and Chimassorb® are protected trademarks of Ciba Specialty Chemicals Corp. Sanduvor® and Hostavin® are protected trademarks of Clariant. Cyasorb® is a protected trademark of Cytec Corporation. Uvinul® is a trademark protected by BASF. Uvasil® is a protected trademark of Enichem. Uvasorb® is a protected trademark of 3V Sigma. The protected amines of component (c) are preferably used in amounts of from about 0.01% to about 10%, in particular from about 0.05% to about 5%, typically from about 0.1% to about 3% by weight, based on the weight of the article polyolefin gap to be stabilized. The stabilizer combination comprising the components (a), (b) and (c), is suitable for stabilizing hollow polyolefin articles which are prepared by the rotomolding process. Among the examples of polyolefins, we have: 1. Mono-olefin polymers and diolefins, for example polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene, polyisoprene or polybutadiene, as well as cycloolefin polymers, for example of norbornene, polyethylene (which may be optionally cross-linked), for example high density polypropylene (HDPE), high density and high molecular weight polypropylene (HDPE-HMW), high density polyethylene and ultra high molecular weight (HDPE) -UHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), (VLDPE) and (ULDPE). The polyolefins, ie the polymers of mono olefins exemplified in the preceding paragraph, preferably polyethylene and polypropylene, can be prepared by diffent met and in particular by the following: i.- radical polymerization (usually under high pressure and at high temperatures) ). ii.- Catalytic polymerization by a catalyst that normally contains one or more of a metals of Groups IVb, Vb, Vlb or VIII of the Table Periodic of the Elements. Said metals usually have one or more binders, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and / or aryls which may be either p- or s- co-orhers. Such metal complexes may be in free form or fixed on substrates, typically on activated magnesium chloride, titanium chloride (III), alumina or silicon oxide. Said catalysts may or may not be soluble in the polymerization medium. The catalysts can be used by themselves in the polymerization or other activators, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyl oxanes can be used, said metals being elements of the Groups la, lia and / or lili a, of the Periodic Table of the Elements. The activators can be conveniently modified with higher ester, ether, amine, or silyl ether groups. These catalyst systems are usually Phillips catalysts, Standard Oil Indiana, Ziegler (-Natta), TNZ (Dupont), metallocene or single site (SSC, single site catalysts). 2. - Mixtures of the polymers mentioned in 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 mono olefins and diolefins with one another or with other vinyl monomers, for example ethylene / propylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylene copolymers / isobutylene, propylene / but-1-ene copolymers, propylene / isobutylene copolymers, ethylene / but-1-ene copolymers, ethylene / hexene copolymers, ethylene / methyl pentene copolymers, ethylhene / heptene copolymers, ethylene / octene copolymers, propylene copolymers / butadiene, isobutylene / isoprene copolymers, ethylene copolymers (alkyl acrylate, 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 the polymers of ethylene with propylene and a diene such as hexadiene, cyclo pentadiene or ethylidene norborene, and mixtures of said copolymers and with polymers mentioned in 1.) above, for example polypropylene / ethylene-propylene copolymers, LDPE / ethylene vinyl acetate (EVA) copolymers, LLDPE / ethylene-acrylic acid (EEA) copolymers, LLDPE / EVA, LLDPE / EEA and alternating or random copolymers of polyalkylene / carbon monoxide and mixtures thereof with other polymers, for example polyamides. The preferred polyf olefins are polyethylene or polypropylene and their copolymers with mono- and diolefins.

In addition to components (a), (b) and (c), the novel process also comprises co-stabilizers (additives) such as for example the following: 1. Antioxidants 1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methyl phenol, 2-tert-butyl-4,6-di methylphenol, 2,6-di-tert-butyl-4-ethyl-enol, 2, 6-di-tert-butyl-4-n-butyl phenol, 2,6-di-tert-butyl-4-isobutyl phenol, 2,6-dicyclopentyl-4-methyl phenol, 2- (a-methylcyclohexyl) -4 , 6-dimethyl phenol, 2,6-dioctadecyl-4-methyl phenol, 2,4,6-tricyclohexyl phenol, 2,6-ditertbutyl-4-methoxymethyl-phenol, nonylphenols which are linear or branched in the side chains, for example 2,6-di-nonyl-4-methyl phenol, 2,4-dimethyl-6- (1'-methyl undec-1'-yl) phenol, 2,4-dimethyl-6- ( 1'-methylhepta dec-1'-yl) phenol, 2,4-dimethyl-6- (1'-methyltridec-1'-yl) phenol and mixtures thereof. 1.2. Alkyltiomethylphenols. for example 2,4-dioctylthiomethyl-6-tert-butyl phenol, 2,4-dioctylthiomethyl-6-methyl phenol, 2,4-dioctylthiomethyl-6-ethyl phenol, 2,6-di-dodecylthiomethyl-4-nonyl phenol . 1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxy phenol, 2,5-di-tert-butyl hydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4 -octadecyloxy phenol, 2,6-di-tert-butyl hydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di stearate -tert-butyl-4-hydroxyphenyl, bis- (3,5-di-tert-butyl-4-hydroxyphenyl) adipate. 1.4. Tocopherols for example a-tocopherol, b-tocopherol, g-tocopherol, d-tocopherol and mixtures thereof (Vitamin E). 1.5. Hydroxylated thiodiphenyl ethers. for example 2,2-thiobis (6-tert-butyl-4-methylene-phenol), 2,2'-thiobis (4-octylphenol), 4,4'-thiobis (6-tert-butyl) -3-methylphenol), 4,4'-thiobis (6-tert- mJbjL.t. »s? ü butyl-2-methylphenol), 4,4, -thiobis- (3,6-di-sec-amylphenol), 4,4'-bis (2,6-dimethyl-4-hydroxyphenyl) disulfide. 1.6. Alauilidenebisphenols. for example 2,2'-methylenebis (6-tert-butyl-4-methylphenol), 2,2'-methylenebis (6-tert-butyl-4-ethylphenol), 2,2, -methylenebis [4-methyl- 6- (α-methylcyclohexyl) phenol], 2,2'-methylene bis (4-methyl-6-cyclohexylphenol), 2,2'-methylene bis (6-nonyl-4-methylphenol), 2,2'- methylene bis (4,6-di-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-tert-butylphenol), 2,2'-ethylidene bis (6-tert-butyl-4-isobutylphenol) ), 2,2'-methylene bis [6- (a-methylbenzyl) -4-nonylphenol], 2,2'-methylene bis [6- (a, a-dimethyl benzyl) -4-nonylphenol], 4, 4'-methylene bis (2,6-di-tert-butyl phenol), 4,4'-methylene bis (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-dodecyl mercapto butane, ethylene glycol bisfS.S-bis-S-tert-butyl -hydroxyphenylJbutyrate], bis (3-tert-butyl-4-hydroxy-5-methyl-phenyl) dicyclopentadiene, bisp-SS'-tert-butyl ^ '-hydroxy-d-methylbenzyl) -6-ter t-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-dodecyl mercaptobutane, 1, 1, 5, 5- tetra- (5-tert-butyl-4-h id roxi-2-meti Ifen il) pentane. 1.7. O- Compounds N- and S-benzyl. for example SdS'.S'-tetra-tert-butiM ^ '- dihydroxy-dibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzyl mercapto acetate, trityl-4-hydroxy-3,5-di- tert-butylbenzyl mercaptoacetate, tris (3,5-di-tert-butyl-4-hydroxybenzyl) amino, bis (4-tert-butyl-3-hydroxy-2,6-d.methylbenzyl) dithioterephthalate, bis (3) , 5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl-3,5-di-tert-butyl-4-hydroxybenzene Imercaptoacetate. a 1.8.- Hydroxybenzyl malonates. for example dioctadecyl-2,2-bis- (3,5-di-tert-butyl-2-hydroxybenzyl) malonate, di-octadecyl-2- (3-tert-butyl-4-hydroxy-5-methylbenzyl) malonate, di-dodecyl mercaptoethyl-2,2-bis- (3,5-di-tert-butyl-4-hydroxybenzyl) malonate, bis [4- (1,1,1,3-tetra methylbutyl) phenyl] -2, 2-bis (3,5-di-tert-butyl-4-hydroxy benzyl) malonate 1.9.- Hydroxybenzyl aromatic compounds, for example 1, 3,5-tris- (3,5-di-tert-butyl-4-) hydroxybenzyl) -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 (octyl mercapto) -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-hydroxy phenoxy) -1, 2,3-triazine, 1, 3 , 5-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1, 3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxyphenylethyl) -1,5,5-triazine, 1, 3,5-tris (3,5-di-tert-butyl-4) -hydroxyphenyl propionyl) -hexahydro-1,3,5-triazine, 1,3,5-tris (3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate. 1.11.- Benzylphosphonates. for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzyl phosphonate, diethyl-3,5-di-tert-butyl-4-hydroxybenzyl phosphonate, dioctadecyl 3,5-di-tert-butyl- 4-hydroxy benzyl phosphonate, dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, the calcium salt of the mono ethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid. 1.12. Acylaminophenols for example 4-hydroxy lauranylide, 4-hydroxy stearanilide, octyl N- (3,5-di-tert-butyl-4-hydroxyphenyl) carbamate. 1. 13. Esters of b- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid with mono- or polyhydric alcohols, for example with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol , 1, 9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, tiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3-decanol tiapenta, trimethylhexane diol, trimethylol propane, 4-hydroxymethyl-1-phospha-2,6,7-trioxa bicyclo [2.2.2] octane. 1.14. Esters of b- (5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid with monohydric or polyhydric alcohols, for example with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexane diol 1, 9-nonanediol, ethylene glycol, 1,2-propane diol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3- tiaundecanol, 3-thiapenta decanol, trimethyl hexanediol, trimethylol propane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo [2.2.2] octane. 1.15. Esters of b- acid (3.5-dicyclohexyl-4-hydroxy phenyl) propionic acid with mono- and polyhydric alcohols, for example methanol, ethanol, octanol, octadecanol, 1, 6-hexanediol, 1, 9-nonane diol, ethylene glycol, 1, 2-propane diol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimetilhexane diol, trimethylolpropane, 4 -hydroxymethyl-1-phospha-2,6,7-trioxa bicyclo [2.2.2] octane. 1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols, for example with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonane diol, ethylene glycol , 1,2-propan diol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaertritol, tris (hydroxyethyl) i socianurato, N, N'-b¡s (hydroxy ethyl) oxamide, 3-thiaundecanol, 3-tiapenta decanol, trimethylhexanediol, trimethylol propane, 4-hydroxymethyl-1-phospha-2,6,7-trioxa bicyclo [2.2.2] octane. 1.17. Amides of b- (3,5-di-tert-butyl-4-hydroxy phenyl) propionic acid for example N, N) is (3,5-di-tert-butyl-4-hydroxyphenyl propionyl) hexamethylene diamide, N.N '-bis (3,5-di-tert-butyl-4-hydroxy-phenylpropionyl) trimethylene diamide, N.N'-bis-S-di-tert-butyl-4-hydroxyphenylpropionyl) hydrazide, N.N'-bis- ÍS- .S-di-tert-buty-hydroxyphenyl] propionyl oxy) ethyl] oxamide (Naugard® XL-1 provided by Uniroyal). 1.18. Ascorbic acid (vitamin C) 1.19.- Amino antioxidants. for example N.N'-di-isopropyl-p-phenylene diamine, N.N'-di-sec-butyl-p-phenylene diamine, N, N'-bis (1,4-dimethylpentyl) -p-phenylene diamine. , N, N'-bis (1-ethyl-3-methylpentyl) -p-phenylene diamine, N.N'-bis (l-methylheptyl) -p-phenylene diamine, N.N'-dicyclohexyl-p-phenylene diamine , N, N'-d-phenyl-p-phenylene diamine, N, N'-bis (2-naphthyl) -p-phenylene diamine, N-isopropyl-N'-phenyl-p-phenylene diamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylene diamine, N- (1-methylheptyl) -N'-phenyl-p-phenylene diamine, N-cyclohexyl-N'-phenyl-p-phenylene diamine, 4- (p-toluene sulphamoyl) diphenylamine, N.N'-dimethyl-N.N'-di-sec-butyl-p-phenylene diamine, diphenylamine, N-allyldiphenyl amine, 4-ylpropoxy diphenylamine, N-phenyl- 1-naphthylamine, N- (4-tert-octylphenyl) -1-naphthyl amine, N-phenyl-2-naphthylamine, dioctylated diphenyl amine, for example p.p'-di-tert-octyldiphenyl amine, 4-n-butylamino phenol, 4-butyrylamino phenol, 4-nonanoyl amino phenol, 4-dodecanoylamino phenol, 4-octadecanoylamino phenol, bis (4-methoxyphenyl) amine, 2,6-di-tert-butyl-4-dimethyl aminomethyl phenol, 2,4'-diamino diphenylmethane, 4,4'-diaminodiphenyl methane, NNN'.N'-tetramethi'-diamino diphenyl methane, 1,2-bis [(2-methylphenyl) amino] ethane, 1 , 2-bis (phenylamino) propane, (o-tolyl) biguanide, bis [4- (1 a.3'-dimethylbutyl) phenyl] amine, N-phenyl-1-naphthylamine tert- ? , r *, r, *? U, r - ". ^? ****, * .l. ^ _..-,., .- ^ ..,. _. .... - ..,. **** .. *. - * - * ~ ** octylated, a mixture of mono- and dialkylated tert-butyl / tert-octyl diphenyl amines, a mixture of mono- and dialkylated nonyl diphenylamines, a mixture of mono- and dialkylated dodecyl diphenylamines, a mixture of isopropyl / iso-hexyl-diphenyl-mono- and dialkylated amines, a mixture of mono- and dialkylated tert-butyldiphenyl amines, 2,3-dihydro-3,3-d-methyl-4H-1,4-benzo thiazine, phenothiazine, a mixture of tert-butyldiphenyl amines -butyl / tert-octylphene mono- and dialkylated thiazines, a mixture of mono- and dialkylated tert-octyl-phenothiazines, NNN'.N'-tetraphenyl-1-diaminobut-2-ene, N, N-bis (2, 2,6,6-tetramethyl-piperid-4-yl-hexamethylene diamine, bis (2, 2,6,6-tetramethyl piperid-4-yl) sebacate, 2,2,6,6-tetramethyl piperidin-4-one , 2,2,6,6- 10 tetramethyl piperidin-4-ol 2.- Absorbers of UV radiation v Light stabilizers: 2.1 2- (2-hydroxyphenyl) benzotriazoles, for example 2- (2 , -hydroxy-5'-methyl phenyl) - benzo triazole, 2- (3 ', 5, -d¡-tert-butyl-2, -hydroxyphenyl) benzotriazole, 2- (5, -ter t-butyl-2'-hydroxyphenyl) benzo triazole, 2- (2, -hydroxy-5, - (1, 1,3,3-tetramethylbutyl) phenyl) benzotriazole, 2- (3 ', 5, -di-tert-butyl-2'-hydroxy phenyl) -5-chloro-benzotriazole, 2- (3'-tert-butyl-2, -hydroxy-5'-methylphenyl) ) -5-chloro-benzo triazole, 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, 2- (3, -tert-butyl-2, -hydroxy-5, - (2-octyloxycarbonyl ethyl) Phenyl) -5-chloro-benzotriazole, 2- (3'-tert-butyl-5, - [2- (2-ethylhexyloxy) -carbonyl-ethyl] -2'-hydroxyphenyl) -5-chloro-benzotriazole, 2- (3, -tert-butyl-2, -hydroxy-5 '- (2-methoxy-carbonylethyl) -phenyl) -5-chloro-benzotriazole, 2- (3'-tert-butyl-2, -hydroxy-5'- (2-methoxycarbonylethyl) phenyl) benzotriazole, 2- (3, -tert-butyl-2'-hydroxy-5, - (2-octyl oxycarbonyllethyl) phenyl) benzotriazole, 2- (3, -tert-butyl-5) '- [2- (2-ethylhexyloxy) carbonylethyl] -25 2'-hydroxyphenyl) benzotriazole, 2- (3, -dodecyl-2, -hydroxy-5, -methylphenyl) benzotriazole, 2- | ^^^. ^ ljM ^^^^ .. ^^^ á < ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - (2-isooctyloxycarbonylethyl) phenylbenzotriazole, 2,2'-methylene-bis [4- (1,1-, 3,3-tetramethylbutyl) -6-benzotriazole-2-l-phenol], the product of transesterification of 2- [3, -tert-butyl-5, - (2-methoxycarbonylethyl) -2, -hydroxyphenyl] -2H-benzotriazole with polyethylene glycol 300; [R-CH2CH -COO-CH2CH] - where R = 3'-tert-butyl-4'-hydroxy-5'-2H-benzo triazol-2-ylphenyl, 2- [2, -hydroxy-3, - (a , α-dimethyl benzyl) -5 '- (1,1-, 3,3-tetramethylbutyl) -phenyl] benzotriazole; 2- [2, -hydroxy-3 '- (1, 1, 3,3-tetramethylbutyl) -5' - (a, a-dimethylbenzyl) -phenyl] benzotriazole. 2.2. 2-Hydroxybenzophenones. for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2, 4'-trihydroxy and 2, -hydroxy-4,4'-dimethoxy derivatives . 2.3. Esters of substituted and unsubstituted benzoic acids such as for example 4-tert-butyl-phenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis (4-tert-butylbenzoyl) resorcinol, benzoyl resorcinol, 2,4-di-tert-butylphenyl 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-hydroxybenzoate. 2.4. Acrylates. for example ethyl a-cyano-β, β-diphenyl acrylate, isooctyl a cyano β, β diphenylacrilate, methyl a-carbomethoxycinnamate, methyl a-cyano-β-methyl-p-methoxy-cinnamate. butyl a cyano-β-methyl-p-methoxy-cinnamate, methyl to carbomethoxy-p-methoxycinnamate and N- (β-carbomethoxy-beta-cyanovinyl) -2-methylindole. 2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis- [4- (1,1,1,3-tetramethylbutyl) phenol], such as the complex 1: 1 or 1: 2, with or without additional binders such as n-butylamine, triethanolamine or N-cyclohexyl diethanolamine, nickel or dibutyldithium carbamate, nickel salts of the mono alkyl esters, for example the methyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzyl phosphonic acid, nickel complexes of ketoximes, for example of 2-hydroxy-4-methylphenyl undecyl ketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazol, with or without additional binders. 2.6.- Oxamides. for example 4,4'-dioctyloxy-oxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy-d.d'-di-tert-butoxyanilide, 2I2'-didodecyloxy-d, di-tert-butoxyanil 2-ethoxy-2'-ethyloxanilide, N, N'-bis (3-dimethylamino propyl) oxamide, 2-ethoxy-d-tert-butyl-2'-ethoxyanilide and its mixture with ^ '-ethyl-d ^ '- di-tert-butoxanilide, mixtures of o- and p-methoxy substituted oxanilides and mixtures of o- and p-ethoxy-substituted oxanilides 2.7.- 2- (2-hydroxy phenol) -1.3.d-triazines . for example 2,4,6-tris (2-hydroxy-4-octyloxyphenyl) -1,3, d-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -416-bis (2,4-dimethylphenyl) -1,3, d-triazine, 2- (2,4-dihydroxy phenyl) -4,6-bis (2,4-dimethylphenyl) -1, 3, d-triazine, 2,4-bis (2-hydroxy) -4-propyloxy-phenyl) -6- (2,4-dimethylphenyl) -1, 3, d-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4,6-bis (4-methylphenyl) -1 , 3, d-triazine, 2- (2-hydroxy-4-dodecyloxy phenyl) -4,6-bis (2,4-dimethyphenyl) -1, 3,5-triazine, 2- (2- hydroxy-4-tridecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1, 3, d-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-butyloxy-propoxy) phenyl] -4,6-bis (2,4-dimethy1) -1,3-d-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-octyloxy-propyloxy) phenyl] -4,6-bis (2,4-dimethyl) -1,3, d-triazine, 2- [4- (dodecyloxy tridecyloxy-2-hydroxypropoxy) -2-hydroxy-phenyl] -4,6-bs (2,4-dimethylphenyl) -1, 3, d-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-dodecyloxy-propoxy) phenyl] -4,6-bis (2,4-dimethyl) phenyl) -1, 3, d-triazine, 2- (2-hydroxy-4-hexyloxy) phenyl-4,6-diphenyl-1,3, d-triazine, 2- (2-hydroxy-4-methoxyphenol) ) -4,6-dife nil-1, 3, d-triazine, 2,4,6-tris [2-hydroxy-4- (3-butoxy-2-hydroxy-propoxy) phen] -1, 3, d-triazine, 2- (2-hydroxyphenyl) -4- (4-methoxy phenyl) -6-phenyl-1,3, d-triazine, 2-. { 2-hydroxy-4- [3- (2-ethylhexyl-1-oxy) -2-hydroxypropyloxy] phenyl} 4,6-bis (2,4-dimethyphenyl) -1,3, d-triazine. 3. Metal dealers, 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 propynyl) hydrazine, 3-salicyloyl amino-1, 2,4-triazole, bis (benzylidene) oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenyl hydrazide, N.N'-diacetyladioyl dihydrazide, N, N ' bis (salicyloyl) oxalyl dihydrazide, N, N'-bis (salicyloyl) thiopropionyl dihydrazide. 4. Nitrones. for example, N-benzyl-alpha-phenyl-nitrona, N-ethyl-alpha-methyl-nitrona, N-octyl-alpha-heptyl-nitrona, N-lauryl-alpha-undecyl-nitrone, N-tetradecyl-alpha- tridecyl-nitrone, N-hexadecyl-alpha-pentadecyl-nitrone, N-octadecyl-alpha-heptadecyl-nitrone, N-hexa decyl-alpha-heptadecyl-nitrone, N-ochatadecyl-alpha-pentadecyl-nitrone, N-heptadecyl-alpha -hepta decyl-nitrona, N-octadecyl-alpha-hexadecyl-nitrone, nitrone derived from N-di (hydrogenated tallow) hydroxylamine. 5. Thiosinérqidas. for example, dilauryl thiodipropionate or distearyl thiodipropionate. 6. Peroxide scavengers, for example esters of b-thiodipropionic acid, for example lauryl, stearyl, myristyl or tridecyl esters, mercapto benzimidazole or the zinc salt of 2-mercapto benzimidazole, zinc dibutyldithium carbamate, dioctadecyl disulfide, pentaerythritol tetrakis ( β-dodecyl mercapto) propionate. 7. Basic co-stabilizers, for example, melamine, polyvinyl pyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkali metal salts of higher fatty acids eg stearate of calcium, calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium riconeleate and potassium palmitate, pyro antimyme catecholate or zinc pyrocatechol. ^^^^ 4 ^ »^., ^^ ..... ^ ,.; ...... «». . * *. tii? ? lffltl MlrttrH? ntir? r i m? r n go r r n r - - * ~~ ** - 8.- Nucleating Agents. for example, substances such as talcum, metal oxides such as titanium dioxide or magnesium oxide, phosphates, carbonates and surtates, preferably alkaline earth metals; organic compounds such as mono- or polycarboxylic acids and the salts thereof, for example 4-tert-butylbenzoic acid, adipic acid, diphenyl acetic acid, sodium succinate or sodium benzoate, polymeric compounds such as ionic copolymers (onomers) ) 9. Loads and reinforcing agents, for example, calcium carbonate, silicates, glass fibers, glass bulbs, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite, sawdust and flours or fibers of other natural products, synthetic fibers. 10. Benzofuranones and indolinone. for example those disclosed in the following documents: U.S. 4,325,863; U.S. 4,338,244; U.S. 5,176,312; U.S. 5,216,062; U.S. 5,262,643; DE-A-4316611; DE-A-4316622; DE-A-4316876; EP-A-0589839 or EP-A-0591102 or 3- [4- (2-acetoxyethoxy) phenyl] -5,7-di-tert-butyl-benzofuran-2-one, 5,7-di-tert-butyl -3- [4- (2-stearoyloxy ethoxy) phenyl] benzofuran-2-one, 3,3'-bis [5,7-di-tert-butyl-3- (4- [2-hydroxy ethoxy] phenyl) benzofuran-2-one], 5,7-di-tert-butyl-3- (4-ethoxyphenyl) benzofuran-2-one, 3- (4-acetoxy-3,5-dimethylphenyl) -5,7-di -tert-butyl-benzofuran-2-one, 3- (3,5-dimethyl-4-pivaloyloxy phenyl) -5,7-di-tert-butyl-benzofuran-2-one, 3- (3,4-dimethylphenyl) ) -5,7-di-tert-butyl-benzofuran-2-one, 3- (2,3-dimethylphenyl) -5,7-di-tert-butyl-benzofuran-2-one. 11.- Other additives. for example, plasticizers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow control agents, optical brighteners, flameproofing agents, antistatic agents, clarifying agents and blowing agents.

The co-stabilizers are added, for example, in concentrations from about 0.01% to about 10% by weight, based on the total weight of the polyolefin to be stabilized. Fillers (loads) and reinforcing agents (item 9 of the list), for example, talc, mica or kaolin, are added to the polyolefins in concentrations from about 0.01% to about 40% by weight, based on the total weight of the polyolefins to be stabilized. The fillers (fillers) and reinforcing agents (item 9 of the list), for example, metal hydroxides, especially aluminum hydroxide or magnesium hydroxide, are added to the polyolefins in concentrations from about 0.01% to about 60% by weight, based on the total weight of the polyolefins to be stabilized. Carbon black (carbon black) is added to the polyolefins in concentrations, judiciously, from about 0.01% to about 5% by weight, based on the total weight of the polyolefins to be stabilized. The glass fibers as reinforcing agents are added to the polyolefins in concentrations, judiciously, from about 0.01% to about 20% by weight, based on the total weight of the polyolefins to be stabilized. A process is preferred which comprises, in addition to components (a), (b) and (c), also other additives, especially phenolic antioxidants, light stabilizers or processing stabilizers.

Especially preferred additional additives include phenolic antoxiodantes (numbers 1.1 to 1.17 in the list) and peroxide scavengers (item 6 in the list). The incorporation of components (a), (b) and (c) and other optional additives into the polyolefin is carried out by known methods, for example before or after the mokdeo or also by applying the mixture stabilizer, dissolved or dispersed, to the polyolefin, with or without the subsequent evaporation of the solvent. The stabilizing mixture of components (a), (b) and (c) and optional additional additives can also be added to the polyolefins to be stabilized in the form of a masterbatch containing these components in a concentration of for example about 2.5% to about 25% by weight. Components (a), (b) and (c), and other optional additives, may also be added before or during polymerization or before crosslinking. The components (a), (b) and (c), and other optional additives, can also be added in the polyolefins to be stabilized, in pure form or encapsulated in waxes, oils or polymers. Components (a), (b) and (c), and other optional additives, can also be sprayed onto the polyolefin to be stabilized. They are capable of diluting other additives (for example, the conventional additives mentioned above) or the same in the molten state in such a way that they can also be sprayed with said additives on the polyolefin to be stabilized. The addition by spraying during the deactivation of the polymerization catalysts is particularly advantageous, it being possible to carry out the spraying by the steam used for deactivation. In the case of sterically polymerized polyolefins it may be advantageous to apply components (a), (b) and (c), optionally together with other additives, by spraying. During the rotomolding process, it is desirable that the temperature reaches a range of about 200 ° C to 400 ° C, preferably about 280 ° C to 400 ° C, for example from about 310 ° C to about 400 ° C. Preferred embodiment of the present invention is that which is refurbished to the use of the stabilizer combination comprising the components (a), (b) and (c), for the polyolefins processed by the rotomolding process. The following Examples illustrate the invention in greater detail. In no way should they be construed as limiting the present invention. We declare that the present invention encompasses all the changes and modifications of the specific examples that do not constitute a deviation from the spirit and scope of the present invention. The parts and percentages are expressed by weight. Example 1: Preparation of Hollow Polyolefin Articles Using the Rotomolding Process 100 parts of medium density polyethylene, copolymerized with hexene Novapol® TR-0735, nominal melt index, 6.8 g / 10 min., Density 0.935 g / cm3) are mixed dry with 0.050 parts of calcium stearate and a combination of additional stabilizers (see below). The mixtures are blended together in pellet form at 232 ° C in a Superior extruder / MPM extruder using a 24: 1 L / D screw with a Maddock mixing head at 100 rpm. The composite pellets are ground to obtain particles of a uniform size (150-500 μm) before the rotational molding process. This step of grinding increases the surface area of the particles, which leads to a faster absorption of heat, so that the overall consumption of energy is reduced. The rotational molding process is carried out in a M20 FSP "ClamsheN", laboratory scale equipment. The ground resin is placed in a cast aluminum mold, which is rotated biaxially in a gas-fired oven. Hot air is circulated by blowers in the chamber while the temperature is increased to 288 ° C for 4 minutes. This temperature is maintained for a specific time (see the following tables). Subsequently the oven is opened and while it is still rotating, the mold is cooled 5 with a forced circulation of air for 7 minutes, followed by a mist of water sprayed for 7 minutes, and an additional step of cooling by air for 2 minutes. Through the entire heating and cooling cycles, the speed of the main shaft is maintained at 6 rpm with a speed ratio of 4.5: 1. After the cooling cycles, the mold is opened and the hollow object is removed. Formulation A (Comparative Example) is additionally mixed with a combination of 0.10 parts of the process stabilizing phosphite, Irgafos® 168, 0.05 parts of the primary antioxidant Irganox® 1076 and 0.200 parts of the Tínuvin® 783 thermal stabilizer. ^^ «* ^ * ^^^^^^^^^^^^ & ^^^^^ - ^^^^^^^^^^^^^^^^^^ ^^ _ ^^^^^^^ Ig ^^ iI ^^^ i_I ^ I_I ^ 1II ^ Formulation B is additionally mixed with a combination of 0.100 parts of the process stabilizing phosphite, Irgafos® 168, 0.050 parts of the hydroxylamine stabilizer of the process Irgastab® 042 and 0.200 parts of the stabilizer to light and heat Tinuvin® 783. Formulation C is additionally mixed with a combination of 0.100 parts of the stabilizing phosphite of the process Irgafos® P-EPQ, 0.050 parts of the hydroxyl amine stabilizer of the process Irgastab® 042 and 0.200 parts of the stabilizer to light and heat Tinuvin® 783. Formulation D is additionally mixed with a combination of 0.100 parts of the stabilizing phosphite of the process Ultranox ® 626, 0.050 parts of the hydroxyl amine stabilizing process Irgastab® 042 and 0.200 parts of the light and heat stabilizer Tinuvin® 783. Irgafos® 168 is tris- (2,4-di-tert-butylphenol) phosphite. Ultranox® 626 is bis (2,4-di-tert-butyl phenyl) pentaeryiritol diphosphite. Irgafos® P-EPQ is tetrakis (2,4-di-tert-butylphenyl) 4,4'-biphenylene-diphosphonite. Irgastab® 042 is N, N-di (alkyl) hydroxylamine produced by the direct oxidation of N, N-di (hydrogenated tallow) amine. Tinuvin® 783 is a combination of the hindered amines of the formulas (H4 (and / H5) Irganox® 1076 is octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate Tinuvin®, Irgafos®, Irgastab® and Irganox® are trademarks of Ciba Specialty Chemicals Corporation Ultranox® is a registered trademark of GE Chemicals AD formulations are molded under rotation to obtain hollow articles, according to the general procedure with retention times ( hold times) from 6 to 14 minutes.

The Yellowness Index of the outer surface is determined by a DCI SF600 spectrophotometer according to ASTM D 1925. An increase in yellowness corresponds to a positive increase in the Yellowness Index. Formulations A-D are vastly superior with respect to Formulation A, standard of comparison, in terms of color stability under these processing conditions. The results have been recorded in Table 1. Table 1: The test of the impact resistance at low temperature is carried out with an impact apparatus Dynatup® 8250 instrumented of free fall (11, 34 kg, 50,8 cm). The test specimens are conditioned in a freezer inside which air circulates, for not less than 12 hours at -40 ° C before the test. The results of the impact resistance test, reported in% fragility, have been reported in Table 2. Formulation B proves to be superior to the standard comparative Formulation A in terms of failure mode based on the tests of the Impact resistance at low temperatures, under these test conditions. Table 2: Impact Resistance Time (Retention% | Fragility) The stabilizer mixtures of the present invention (Formulations BD) are superior in comparison to a stabilizer mixture corresponding to the state of the art (Formulation A) in the prevention of color formation and for the provision of stability to hollow polyolefin articles. produced by the rotomolding process. Example 2: Preparation of Hollow Polyolefin Articles By the Rotomoulding Process The hollow articles are produced according to Example 1, replacing Tinuvin MR 783 of Formulation B for each of the following hindered amine stabilizers: Formulation E: Irgafos® 168, Irgastab® 042 and Tinuvin® 622 (composed of the Formula (H4)). Formulation F: lrgafos®168, lrgastab®042 and Chimassorb®944 (compound of Formula (H5)). Formulation G: lrgafos®168, lrgastab®042 and Chimassorb®119 (composed of the Formula (H9)). Formulation H: lrgafos®168, lrgastab®042 and Tinuvin®111 (a mixture of the formulas (H4) and (H9)). Formulation I: lrgafos®168, lrgastab®042 and Chimassorb®2020 (composed of the Formula (H10)).

Formulation J: lrgafos®168, lrgastab®042 and Cyasorb® UV-3346 (compound of Formula (H12)). Formulation K: lrgafos®168, lrgastab®042 and Cyasorb®UV-3529 (compound of Formula (H13)). Formulation L: lrgafos®168, lrgastab®042 and Uvasorb®HA88 (composed of the Formula (H17)). Formulation M: lrgafos®168, lrgastab®042 and Tinuvin®123 (composed of the Formula (H1)). Formulation N: lrgafos®168, lrgastab®042 and the hindered amine of the Formula (H11). Formulation O: lrgafos®168, lrgastab®042 and Hostavin®N30 (composed of the Formula (H14)). Formulation P: lrgafos®168, lrgastab®042 and Uvinul®5050H (composed of the Formula (H15)). Formulation Q: lrgafos®168, lrgastab®042 and Uvasil®299 (composed of the Formula (H16)). Formulation R: lrgafos®168, lrgastab®042 and Uvasorb®HA88 (composed of the Formula (H17)). Irgafos®168 is tris (2,4-ditert-butylphenyl) phosphite. Irgastab®042 is a di (alkyl) hydroxylamine produced by the direct oxidation of N, N-di (tallow hydrogen) amine. Irgafos®, Irgastab®, Tinuvin® and Chimassorb® are protected trademarks of Ciba Specíalty Chemicals Corporation. Cyasorb® is a protected trademark of Cytec Corporation. Hostavin® is a protected trademark of Clariant. Uvinul® is a trademark protected by BASF. Uvasil is a protected trademark of Enichem. Uvasorb is a protected trademark of 3V Sigma. The stabilizer mixtures of the present invention (ER Formulations) are superior in comparison to a stabilizer mixture corresponding to the state of the art (Formulation A) as regards the prevention of color formation and for the provision of stability to the hollow polyolefin articles. produced by the rotomolding process. Example 3: Preparation of Hollow Polyolefin Articles By the Rotomoulding Process The hollow articles are prepared as in Example 1, replacing Irgastab® 042 by N, N-dibenzyl hydroxylamine in the Formulations B-D. The stabilizing mixtures of the present invention, comprising an organic phosphite or phosphonite, N, N-dibenzylhydroxyl amine and Tinuvin® 783, are superior in comparison with a stabilizing mixture corresponding to the current state of the art (Formulation A) as regards the prevention of the formation of colors and to provide stability to the hollow polyolefin articles produced by the rotomolding process. Example 4: Preparation of Hollow Polyolefin Articles Through the Rotomolding Process Hollow articles are produced according to Example 1, replacing Irgafos® 168 of Formulation B with the stabilizing phosphite of the Irgafos ® 38 Process. Irgafos® 38, provided by Ciba Specialty Chemicals Corporation, en (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite.

The formulation of the present invention comprising Irgafos 38 is superior to a stabilizer mixture corresponding to the state of the art (Formulation A) as regards the prevention of color formation and for the provision of stability to the hollow polyolefin articles produced by the rotomolding process. Example 5: Preparation of Hollow Polyolefin Articles By the Rotomoulding Process The hollow articles are prepared as in Example 1, replacing Irgastab® 042 of Formulations B-D with Genox® EP amine oxide. The stabilizing mixtures of the present invention, which comprise an organic phosphite or phosphonite, Genox® EP and Tinuvin® 783, are superior in comparison with a stabilizing mixture corresponding to the current state of the art (Formulation A) as regards the prevention of the formation of colors and to provide stability to the hollow polyolefin articles produced by the rotomolding process. Genox® EP is an oxide of di (C6- C18) alkylmethylamine, CAS # 204933-93-7, provided by GE Specialty Chemicals. Example 6: Preparation of Hollow Polyolefin Articles Using the Rotomoulding Process Hollow articles are produced according to Example 1, replacing Irgafos ® 168 and Irgastab ® 042 Formulation B with the stabilizing phosphite of the Irgafos ®3 process and by the amine oxide Genox® EP, respectively. Irgafos® 38, provided by Ciba Specialty Chemicals Corporation, is bis (2,4-di-tert-butyl-6-methylphenol) ethyl phosphite. Genox® EP is a di (C? 6-) oxide *? * ^ í, -., »,» «- .. _, *, ***. ** ...

C? S) alkylene methyl amine, CAS # 204933-93-7, provided by GE Specialty Chemicals. The formulation of the present invention comprising Irgafos ® 38, Genox EP and Tinuvin ® 738, is superior to a stabilizer mixture corresponding to the state of the art (Formulation A) as regards the prevention of color formation and for the provision of stability to the hollow polyolefin articles produced by the rotomolding process.

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Claims

A process for the production of hollow polyolefin articles, comprising introducing a stabilizer combination into the polyolefin, which combination comprises: a.- at least one compound selected from the group consisting of: organic phosphites and phosphonites , b.- one or more compounds selected from the group consisting of; i.- derivatives of hydroxylamines, and ii.- derivatives of amine oxides, and c ,. at least one compound selected from the group consisting of the stabilizing amine oxides, to fill a mold with this mixture, to heat this mold in an oven to more than 280 ° C, in such a way that the stabilized polyolefin is melted, to rotate the mold around at least two axes, distributing the plastic material to the walls, cooling the mold while it is still rotating, opening it, and extracting the resulting hollow article. 2. A process according to claim 1, wherein the organic phytosites and phosphonites of component (a) are selected from the group consisting of formulas (1), (2), (3), (4) , (5), (6) and (7): (2) (7) in which the sub-indices are integers, and n is 2, 3 or 4; p is 1 or 2; q is 2 or 3; r is worth 4 to 12; and is worth 1, 2 or 3; and z is worth 1 to 6;
Ai, if f n is 2, represents C 2 -C 8 alkylene; C2-C? 2 alkylene interrupted by or
A-i, if n is 3, represents a radical of the formula -CrH2r -? -;
Ai, if n is 4, represents CH - CH, - C - (I CH, - A2 is as defined for Ai if n is 2, B is a direct bond, -CH2-, -CHR4-, -CR? R - , sulfur, C5-C7 cycloalkylidene, or cyclohexylidene which is substituted by from 1 to 4 alkyl radicals of 1 to 4 carbon atoms in the 3, 4 and / or 5 position; Di, if p is 1., represents alkyl of 1 to 4 carbon atoms and, if p = 2, represents -CH2OCH2-; D2, if p = 1, represents alkyl of 1 to 4 carbon atoms, E, if y = 1, represents alkyl of 1 to 18 carbon atoms , -OR1 or halogen; E, if y = 2, represents -O-A2-O-, E, if y = 3, is a radical of the formula R4C (CH2O-) 3 or N (CH2CH2O-) 3; Q is the radical of at least z-valent alcohol or phenol, said radical being linked by the oxygen atom to the phosphorus atom, R1, R2 and R3 independently of each other represent alkyl of 1 to 18 carbon atoms which is substituted or unsubstituted by halogen, -COOR, -CN or - CONR4R; alkyl of 2 to 18 carbon atoms carbon interrupted by oxygen, sulfur or -NR-; C7-Cg phenyl alkyl, Cs-C? 2 cycloalkyl, phenyl or naphyl; Naphthyl or phenyl substituted by halogen, having from 1 to 3 alkyl radicals a total of 1 to 18 atoms of carbon or by C7-Cg phenyl alkyl; or a radical of the Formula R.
- (CH2) -? - OH in which m is an integer in the range of 3 m R to 6;
R4 is hydrogen, C? -C18 alkyl, C5-C? 2 cycloalkyl or C7-C9 phenylalkyl, Rs and Re independently from each other, represent hydrogen, Ci-C? Alkyl or
C5-C6 cycloalkyl, R and Rs, if q = 2, independently of each other, represent C1-C4 alkyl or together form a 2,3-hydroquinone pentamethylene radical; and R7 and Rs. if q = 3, they represent methyl; R14 is hydrogen, C1-C9 alkyl or cyclohexyl, R15 is hydrogen or methyl and, if there are two or more radicals R14 and R15 present, these radicals are identical or different, X and Y, are each a direct bond or oxygen; Z is a direct bond, methylene, -C (Rβ) 2- or sulfur, and R16 is C-i-Cβ alkyl. 3. A process according to claim 1, wherein the organic phosphites and phosphonites of component (a) are selected from the group consisting of: tris (2,4-di-tert-butylphyl) phosphite , tris (nonylphenyl) phosphite and the formulas (A), (B), (C), (D), (E), (F), (G), (H), (J), (K) and ( L)
(H) (K) ^ --- - - • * - - * - ---'- -. --- * - «- '- -t-M = a-ÜM ^ 4.- A process according to claim 1, in which the hydroxyl amine derivatives are of the formula (II): wherein: Ti is linear or branched alkyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, or said aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms or by one or two halogen atoms: T2 is hydrogen, or independently It has the same meaning as Ti. 5. A process according to claim 4, in which Ti and T2 are independently benzyl, ethyl, octyl, lauryl, dodecyl, tetradecyl, hexadecyl, heptadecyl or octadecyl. 6. A process according to claim 1 in which the hydroxylamine derivatives of component (i) are selected from the group consisting of; N, N-dibenzylhydroxamine, N, N-diethylhydroxyl amine, N, N-dioctylhydroxyl amine, N, N-dilaurylhydroxyl amine, N, N-didodecylhydroxyl amine, N, N -tetradecyl hydroxylamine, N, N-dihexadecyl hydroxylamine, N, N-dioctadecylhydroxyl amine, N-hexadecyl-N-tetradecyl hydroxylamine, N-hexadecyl-N-heptadecyl hydroxylamine, N-hexadecyl-N-octadecyl hydroxylamine, N-heptadecyl-N-octadecyl hydroxylamine, and N, N-di (tallow hydrogen) hydroxylamine. 7. A process according to claim 1, wherein the component (i) is a N, N-di (alkyl) hydroxylamine produced by the direct oxidation of the N, N-di (halogenated tallow) amine. + 8.- A process according to claim 1, wherein the amine oxide derivatives of component (i) correspond to the following formula:
G, - • G, (III) G '2, in which: Gi and G2 are independently from each other a linear or branched alkyl of 6 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36 carbon atoms, alkyl cycloalkyl of 6 to 36 carbon atoms or alkylalkyl cycle of 6 to 36 carbon atoms. G3 is a linear or branched alkyl of 1 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36 carbon atoms carbon, alkyl cycloalkyl of 6 to 36 carbon atoms or alkylalkyl cycle of 6 to 36 carbon atoms; with the proviso that at least one of G-i, G2 and G3 contains a carbon ß-hydrogen bond; and wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groups can be interrupted by one to sixteen groups -O-, -S-, -SO-, -SO2-, -COO-, -OCO-, -CO-, -NG-, -CONG- and -NG4CO-, or in which said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkyl alkyl groups can be substituted for one to sixteen selected groups from among the group consisting of; -OG4, -SG4, -COOG4, -OCOG4, -COG4, -N (G4) 2, -CON (G4) 2, -NG4COG4 and 5 and 6 membered rings containing the group -C (CH3) (CH2RX) NL (CH2RX) (CH3) C- or in which said alkyl, aralkyl, alkaryl, cycloalkyl, alk-cycloalkyl and cycloalkyl groups are both interrupted and substituted by the aforementioned groups; and wherein G4 is independently hydrogen or alkyl of 1 to 8 carbon atoms; R x is hydrogen or methyl, preferably hydrogen; L is a linear or branched alkyl part of 1 to 30 carbon atoms, a part -C (O) R in which R is a straight or branched chain alkyl group of 1 to 30 carbon atoms, or a part -OR wherein R is a straight or branched chain alkyl group of 1 to 30 carbon atoms; and wherein said aryl groups can be substituted by one to three halogen atoms, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms or combinations thereof. 9. A process according to claim 8 in which G1 and G2 are independently linear or branched alkyl groups of 6 to 22 carbon atoms and G3 is a straight or branched chain alkyl of 1 to 22 carbon atoms .
10. A process according to claim 8, wherein G3 is methyl.
11. - A process according to claim 8, in which Gi and G2 are independently from each other a straight or branched chain alkyl of 12 to 22 carbon atoms and G3 is methyl.
12. A process according to claim 8, in which G1, G2 and G3 are, independently of each other, a straight or branched chain alkyl of 12 to 22 carbon atoms.
13. A process according to claim 8, wherein the amine oxide derivatives of component (ii) are selected from the group consisting of; didecyl methyl amine oxide, tridecyl amine oxide, tridodecyl methyl amine oxide and trihexadecyl amine oxide.
14. A process according to claim 8, wherein at least one of G1, G2 and G3 comprises at least one part selected from the group consisting of: -O-, -S-, -SO- , -COO-, -CO- and -CONG4-.
15. A process according to claim 1, wherein the amine oxide derivatives are poly (amines) oxides.
16. A process according to claim 15, wherein the oxides of (polyamines) comprise at least a part of the group consisting of -O-, -S-, -SO-, -COO-, -CO - and -CONG4-.
17. A process according to claim 8 in which one of G-i, G2 and G3 is substituted by one to sixteen groups of the formulas (IV) and (V), »" ** • »* - wherein: Rx is hydrogen or methyl; L is a straight or branched chain alkyl part of 1 to 30 carbon atoms, a part -C (O) R in which R is a straight or branched chain alkyl group of 1 to 30 carbon atoms, or a part -OR in which R is a straight or branched chain alkyl group of 1 to 30 carbon atoms.
18. A process according to claim 1, wherein the hindered amine stabilizers of component (c) contain at least one group of the following formula: in which Rx is hydrogen or methyl.
19. A process according to claim 18 in which the hindered amines stabilizers are selected from the group consisting of; the formulas H1), (H2), (H3), (H4), (H5), (H6), (H7), (H8), (H9), (H10), (H11), (H12), ( H13), (H14), (H15), (H16) and (H17) ... . **, *** .. ......._......, ........ -,. ^ - »A» .. R 'R' I R '- NH - (CH2) 3- - (CH2) 2- N - (CH2) 3-NH-R' (H9) (H10) (H11) s ^ ¿^ (H17) in which m and m are numbers in the range of 2 to 200.
20. A process according to claim 1, wherein the temperature reaches the range of about 200 ° C to 400 ° C.
21.- The use of a mixture of components (a), (b), and (c) according to claim 1, as polyolefin stabilizers processed by the rotomolding method.