CA2501384C - Flame retardant compositions - Google Patents

Abstract

Organic polymeric substrates, for example polyolefins such as polypropylene, can be made flame retardant by the incorporation of a synergistic mixture of (i) at least one sterically hindered amine stabilizer, (ii) at least one conventional flame retardant selected from the group consisting of the organohalogen, phosphorous containing, isocyanurate and melamine based flame retardants and (iii) at least one acid scavenger. The compositions of the invention combine good flame retardant properties with light stability and good mechanical properties. Polyolefin molded articles are stabilized against light, heat and oxygen and made flame retardant with the incorporation of at least one sterically hindered amine and at least one conventional flame retardant, while allowing normally high levels of flame-retardant fillers to be greatly reduced or eliminated.

Description

FLAME RETARDANT COMPOSITIONS

The instant invention pertains to a novel method of flame retarding a polymeric substrate by adding thereto an effective flame retarding amount of a synergistic mixture of at least one sterically hindered amine stabilizer, at least one conventional flame retardant and at least one acid scavenger.

The instant invention also pertains to polyolef in molded articles that are stabilized against light, heat and oxygen and made flame retardant with the incorporation therein of at least one sterically hindered amine stabilizer and at least one conventional flame retardant, while allowing normally high levels of flame-retardant fillers to be greatly reduced or eliminated.

Background of the Invention U.S. Pat. No. 5,096,950 discloses the co-use of certain NOR (N-alkoxy) hindered amines with a brominated Sb203-containing flame retardant in polypropylene.

U.S. Pat. No. 5,393,812 discloses polyolef in compositions which are made flame retardant by a combination of a halogenated hydrocarbyl phosphate or phosphonate ester flame retardant in combination with a alkoxyamine functional hindered amine.

U.S. Pat. No. 5,844,026 discloses polyolefin compositions comprising certain NOR
hindered amines and certain traditional flame retardants.
U.S. Pat. No. 6,117,995 discloses that certain N-alkoxy hindered amines may be used as flame retardants for organic polymers.

U.S. Pat. No. 6,271,377 discloses polyolefin compositions that comprise N-hydroxyalkoxy hindered amines and a halogenated flame retardant.

U.S. Pat. No. 6,309,987 and equivalent WO 99/54530 teach polyolefin non-woven flame retardant fabrics that comprise N-alkoxyamines.

U.S. Pat. No. 6,262,161 discloses random interpolymers, for example polymers of ethylene and/or one or more a-olefin monomers with one or more vinyl aromatic monomers, with improved ignition resistance that comprises a filler and at least one other component .5 which may be a hindered amine stabilizer-A Revolutionary UV Stable Flame Retardant System for Polyolefins - R.
Srinivasan., A. Gupta and D. Horsey, /nt. Conf Addit. Polyolefins 1998, 69-83, teaches polyolefins comprising certain NOR hindered amines with halogen and phosphorus containing traditional , flame retardants.

Advances in a Revolutionary Flame Retardant System for Polyolefins - R_ Srinivasan, B_ Rotzinger, Polyolefins 2000, Int. Conf. Polyolefins 2000, 571-581, teaches polyolefins comprising certain NOR hindered amines with brominated and phosphorus containing flame retardants.

N. Kaprinidis and R. King, in an abstract posted on the Society of Plastics Engineers website, posted Sep. 2001, discuss the use of NOR hindered amines as flame retardants in polyolefins. The abstract is for a paper submitted to the Polymer Modifiers and Additives Division subsection to be presented at the Polyolefins 2002 conference in Houston, TX, Feb.
24,2002- The website is www.PMAD.org_ EP 0792911 A2, discloses polyolefin compositions that comprise alkoxyamine functional hindered amines and tris(trihalogenopentyl) phosphate flame retardants.
WO 99/00450, U.S. Patent No. 6,599,963, and U.S. Patent No. 6,472,456, disclose the use of certain N-alkoxy hindered amines as flame retardants.

EP 1038912 discloses specific hydrocarbyloxy hindered amine compounds as flame retardants.

Research Disclosure, Sept. 2000, No. 437087, June 2000, No. 434095 and Dec.
2000, No. 440128 also disclose the efficacy of certain hydrocarbyloxy hindered amine compounds as flame retardants.

U.S. Pat. No. 6,225,387 discloses organohalide flame retardant polymer compositions.

The flame retardant (FR) market today is comprised of products which function to interfere with the combustion process by chemical and/or physical means.
Mechanistically these FRs have been proposed to function during combustion of an article in either the gas phase, the condensed phase or both. The organohalogens are proposed to generate halogen species (e.g. HX) which interferes in the gas phase with free radical organic "fuel"
from the polymer substrate. Synergists are proposed to react with HX to form additional chemical species which interfere with combustion in the gas phase, such as reaction of antimony oxide with HX to form antimony halide and water vapor. Antimony compounds such as antimony trioxide also act as a radical scavenger forming antimony halides. Thus, it can inhibit the propagation of the fire.

Although antimony compounds are efficient in terms of cost performance, it recently raised a lot of concern because of the toxicity of the byproducts which are formed during combustion in the presence of a halogenated flame retardant. Antimony oxides often contain trace amounts of arsenic compounds which are suspected carcinogens. Because of these ecological concerns, there is a motion to replace antimony trioxide in the present commercial flame retardant applications. However, it is very difficult to find an effective synergist which is -both enviromentally friendly and efficient as far as the cost performance is concerned.
Another reason to add flame retardant additives is to prevent dripping during the application of the fire. Dripping during combustion is the process of the separation of parts of the polymer from the matrix in the shape of droplets. Most often, the droplets are flaming and are imposing tremendous danger for fire spread. It is a common measure to add fillers such as talc in large amounts to the polymer, with some negative consequences on the mechanical properties. Fillers sometimes used include calcium carbonate, magnesium carbonate, zinc borate, silicates, silicones, glass fibres, glass bulbs, asbestos, kaolin, mica, barium sulfate, calcium sulfate, metal oxides, hydrates and hydroxides such as zinc oxide, magnesium hydroxide, alumina trihydrate, silica, calcium silicate and magnesium silicate.

It has been found that polymers with good flame retardant properties are prepared .5 when a sterically hindered amine stabilizer is added thereto together with a conventional organohalogen flame retardant, phosphorus containing flame retardant, isocyanurate flame retardant or melamine based flame retardant and with an acid scavenger. With this combination, flame-retardant fillers or conventional fillers may be largely reduced or replaced. As the instant hindered amine compounds are active as stabilizers, the polymer compositions of the invention are efficiently protected from the deleterious effects of light, oxygen and/or heat.

Detailed Disclosure The instant invention pertains to a flame retardant polymer composition which comprises (a) an organic polymer substrate and (b) an effective flame retarding amount of a synergistic mixture of (i) at least one sterically hindered amine stabilizer, (ii) at least one conventional flame retardant selected from the group consisting - of the organohalogen, phosphorus containing, isocyanurate and melamine based flame retardants and (iii) at least one acid scavenger.

- 4a -According to another aspect of the present invention, there is provided a flame retardant polymer composition which comprises (a) an organic polymer substrate and (b) an effective flame retarding amount of a synergistic mixture of (i) at least one sterically hindered amine stabilizer, (ii) tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate and (iii) at least one acid scavenger selected from the group consisting of hydrotalcites, where the stabilizers of component (i) are of the formula E-N

where G, and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z1 and Z2 are each methyl, or Zi and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is cyclohexyloxy; and where the acid scavengers of component (iii) are present from about 0.1 % to about 1.0% by weight based on component (a).

According to still another aspect of the present invention, there is provided a process for imparting light stability and flame retardancy to an organic polymer substrate, which process comprises adding to said polymer substrate (i) at least one sterically hindered amine stabilizer, (ii) tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate and (iii) at least one acid scavenger selected from the group consisting of hydrotalcites, where the stabilizers of component (i) are of the formula E-N

-4b-where G1 and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z1 and Z2 are each methyl, or Z1 and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is cyclohexyloxy; and where the acid scavengers of component (iii) are present from about 0.1 % to about 1.0% by weight based on the polymer substrate.

According to yet another aspect of the present invention, there is provided a flame retardant additive combination comprising (i) at least one sterically hindered amine stabilizer, (ii) tris[3-bromo-2,2-bis(bromomethyl)propyl]
phosphate and (iii) at least one acid scavenger selected from the group consisting of hydrotalcites, where the stabilizers of component (i) are of the formula E-N

i~7_ Z2 where G1 and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z1 and Z2 are each methyl, or Z1 and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is cyclohexyloxy; and where the acid scavengers of component (iii) are present from about 0.1 % to about 1.0% by weight based on component (a).

Flame-retardant fillers are not required in order to improve the flame retardant properties and achieve a higher rating, e.g. in the UL-94 burning test (infra). Consequently, the compositions of the present invention may contain only minor amounts of flame-retardant fillers, e.g. less than about 3%, for instance less than about 1 %, for example less than about 0.1 % by weight of the polymer component A; for example, the present compositions are essentially free of flame-retardant fillers.

Flame-retardant fillers are known in the art and are selected from the group consisting .5 of magnesium hydroxide, alumina trihydrate and zinc borate. Flame-retardant fillers are inorganic compounds employed for flame-retardant properties, and at high enough levels to be considered "filler".

If conventional fillers such as talc, calcium carbonate and the like are normally employed for instance for flow properties in order to reduce the spread of flaming droplets (not flame-retardant per se), such conventional fillers may also be reduced with the use of the present compositions. For instance, the present compositions may contain only minor amounts of conventional fillers, for example less than about 3%, for instance less than 1 %, for example less than about 0.1 % by weight of the polymer component A; for example, the present compositions are essentially free of conventional fillers.

Further, the present invention allows for conventional fillers to take the place of more expensive flame-retardant fillers.

The present compositions meet flame retardant specifications while containing no or only minor amounts of antimony compounds such as Sb203, e.g. less than about 1 %, for instance less than about 0.1 % by weight of component (a); for example, the present compositions are essentially free of antimony.

-Polymer Substrate (a) The polymeric substrate of component (a) is any of a wide variety of polymeric types including polyolef ins, polystyrenics, and PVC. For example, the polymer substrate may be selected from the group of resins consisting of the polyolefins, the thermoplastic (poly)olefins, styrenic polymers and copolymers, ABS and polymers which contain hetero atoms, double bonds or aromatic rings. Specific embodiments are where component (a) is polypropylene, polyethylene, thermoplastic polyolefin (TPO), ABS or high impact polystyrene.

For example, the polymer substrate is selected from the group of resins consisting of the polyolefins, the thermoplastic polyolefins, styrenic polymers and copolymers, and ABS.
Another embodiment of the present invention is where the polymer substrate is selected from the group consisting of polypropylene, polyethylene, thermoplastic polyolefin (TPO), ABS and high impact polystyrene.

For instance, the polymer substrate is polypropylene, polyethylene or thermoplastic polyolefin (TPO). Organic polymers of component A are for example thermoplastic polymers such as polyolefins like polyethylene, polypropylene or copolymers thereof.
The thermoplastic polymer is for example polypropylene.

Further examples for organic polymers (component A) are:

1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, po-lybut-1 -ene, poly-4-methylpent-1 -ene, polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene (which optionally can be crosslinked), for example high density polyethylene (HDPE), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), (VLDPE) and (ULDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in the preceding paragraph, for -example polyethylene and polypropylene, can be prepared by different, and especially by the following, methods:

a) radical polymerisation (normally under high pressure and at elevated temperature).

b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups lVb, Vb, Vlb or VIII of the Periodic Table. These metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either it- or a-coordinated.
These metal complexes may be in the free form or fixed on substrates, typically on activated magnesium chloride, titanium(III) chloride, alumina or silicon oxide. These catalysts may be soluble or insoluble in the polymerisation medium. The catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal .5 alkyloxanes, said metals being elements of groups Ia, Ila and/or Isla of the Periodic Table. The activators may be modified conveniently with further ester, ether, amine or silyl ether groups. These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).
2. Mixtures of the polymers mentioned under 1), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, 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 monomers, 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, ethylene/but-1-ene copolymers, ethylene/hexene copo-lymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers (e.g.
ethylene/norbornene like COC), ethylene/1-olefins copolymers, where the 1-olefin is gene-rated in-situ; propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene/vi-nylcyclohexene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acid copolymers and their -salts (ionomers) as well as terpolymers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene-norbornene; and mixtures of such copolymers with one another and with polymers mentioned in 1) above, for example polypropylene/ethy-lene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyal-kylene/carbon monoxide copolymers and mixtures thereof with other polymers, for example polyamides.

4. Hydrocarbon resins (for example C5-C9) including hydrogenated modifications thereof (e.g. tackifiers) and mixtures of polyalkylenes and starch.

Homopolymers and copolymers from 1.) - 4.) may have any stereostructure including syndio-tactic, isotactic, hemi-isotactic or atactic; for example atactic polymers.
Stereoblock polymers are also included.
5. Polystyrene, poly(p-methylstyrene), poly(a-methylstyrene).

6. Aromatic homopolymers and copolymers derived from vinyl aromatic monomers including styrene, a-methylstyrene, all isomers of vinyl toluene, especially p-vinyltoluene, all isomers of ethyl styrene, propyl styrene, vinyl biphenyl, vinyl naphthalene, and vinyl anthracene, and mixtures thereof. Homopolymers and copolymers may have any stereostructure including syndiotactic, isotactic, hemi-isotactic or atactic; for example atactic polymers. Stereoblock polymers are also included.

6a. Copolymers including aforementioned vinyl aromatic monomers and comonomers selec-ted from ethylene, propylene, dienes, nitriles, acids, maleic anhydrides, maleimides, vinyl acetate and vinyl chloride or acrylic derivatives and mixtures thereof, for example styrene/bu-tadiene, styrene/acrylonitrile, styrene/ethylene (interpolymers), styrene/alkyl methacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic anhy-dride, styrene/acrylonitrile/methyl acrylate; mixtures of high impact strength of styrene copo-lymers and another polymer, for example a polyacrylate, a diene polymer or an ethylene/pro-pylene/diene terpolymer; and block copolymers of styrene such as styrene/butadiene/sty-rene, styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propy-lene/styrene.
-6b. Hydrogenated aromatic polymers derived from hydrogenation of polymers mentioned under 6.), especially including polycyclohexylethylene (PCHE) prepared by hydrogenating atactic polystyrene, often referred to as polyvinylcyclohexane (PVCH).

6c. Hydrogenated aromatic polymers derived from hydrogenation of polymers mentioned under 6a.).

Homopolymers and copolymers may have any stereostructure including syndiotactic, isotac-tic, hemi-isotactic or atactic; for example atactic polymers. Stereoblock polymers are also included.

7. Graft copolymers of vinyl aromatic monomers such as styrene or a-methylstyrene, for example styrene on polybutadiene, styrene on polybutadiene-styrene or polybutadiene-acry-lonitrile copolymers; styrene and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene; styrene and maleic anhydride on polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide on polybutadiene;
styrene and maleimide on polybutadiene; styrene and alkyl acrylates or methacrylates on polybutadiene; styrene and acrylonitrile on ethylene/propylene/diene terpolymers; styrene and acrylonitrile on polyalkyl acrylates or polyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadiene copolymers, as well as mixtures thereof with the copolymers listed under 6), for example the copolymer mixtures known as ABS, MBS, ASA or AES polymers.
8. Halogen-containing polymers such as polychloroprene, chlorinated rubbers, chlorinated and brominated copolymer of isobutylene-isoprene (halobutyl rubber), chlorinated or sulfo-chlorinated polyethylene, copolymers of ethylene and chlorinated ethylene, epichlorohydrin homo- and copolymers, especially polymers of halogen-containing vinyl compounds, for example polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, as well as copolymers thereof such as vinyl chloride/vinylidene chloride, vinyl chloride/vinyl acetate or vinylidene chloride/vinyl acetate copolymers.

9. Polymers derived from a,(3-unsaturated acids and derivatives thereof such as polyacry--fates and polymethacrylates; polymethyl methacrylates, polyacrylamides and polyacryloni-triles, impact-modified with butyl acrylate.

10. Copolymers of the monomers mentioned under 9) with each other or with other unsatu-rated monomers, for example acrylonitrile/ butadiene copolymers, acrylonitrile/alkyl acrylate copolymers, acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide copolymers or acry-lonitrile/ alkyl methacrylate/butadiene terpolymers.

11. Polymers derived from unsaturated alcohols and amines or the acyl derivatives or ace-tals thereof, for example polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, polyallyl phthalate or polyallyl melamine; as well as their copolymers with olefins mentioned in 1) above.

12. Homopolymers and copolymers of cyclic ethers such as polyalkylene glycols, polyethy-lene oxide, polypropylene oxide or copolymers thereof with bisglycidyl ethers.

13. Polyacetals such as polyoxymethylene and those polyoxymethylenes which contain ethylene oxide as a comonomer; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS.

14. Polyphenylene oxides and sulfides, and mixtures of polyphenylene oxides with styrene polymers or polyamides.

15. Polyurethanes derived from hydroxyl-terminated polyethers, polyesters or polybutadi-enes on the one hand and aliphatic or aromatic polyisocyanates on the other, as well as precursors thereof.

16. Polyamides and copolyamides derived from diamines and dicarboxylic acids and/or from aminocarboxylic acids or the corresponding lactams, for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide 12, aromatic polyamides starting from m-xylene diamine and adipic acid; polyamides prepared from hexamethylenediamine and isophthalic or/and terephthalic acid and with or without an ela-stomer as modifier, for example poly-2,4,4,-trimethylhexamethylene terephthalamide or poly-m-phenylene isophthalamide; and also block copolymers of the aforementioned polyamides -with polyolefins, olefin copolymers, ionomers or chemically bonded or grafted elastomers; or with polyethers, e.g. with polyethylene glycol, polypropylene glycol or polytetramethylene glycol; as well as polyamides or copolyamides modified with EPDM or ABS; and polyamides condensed during processing (RIM polyamide systems).

17. Polyureas, polyimides, polyamide-imides, polyetherimids, polyesterimids, polyhydantoins and polybenzimidazoles.

18. Polyesters derived from dicarboxylic acids and diols and/or from hydroxycarboxylic acids or the corresponding lactones, for example polyethylene terephthalate, polybutylene tereph-thalate, poly- 1,4-dimethylolcyclohexane terephthalate, polyalkylene naphthalate (PAN) and polyhydroxybenzoates, as well as block copolyether esters derived from hydroxyl-terminated polyethers; and also polyesters modified with polycarbonates or MBS.

19. Polycarbonates and polyester carbonates.

20. Polyketones.

21. Polysulfones, polyether sulfones and polyether ketones.

22. Blends of the aforementioned polymers (polyblends), for example PP/EPDM, Poly-amide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA 6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or PBT/PET/PC.

Sterically Hindered Amine Stabilizers of Component (i) The present hindered amines are for example monomeric compounds or are oligomeric or polymeric compounds.

The present sterically hindered amine stabilizers of component (i) are known in the art, and are for example of the formula -E -N

Gt G

where G, and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z, and Z2 are each methyl, or Z, and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is oxyl, hydroxyl, alkoxy, cycloalkoxy, aralkoxy, aryloxy, -O-CO-OZ3, -O-Si(Z4)3i -O-PO(OZ5)2 or -O-CH2-OZ6 where Z3, Z4, Z5 and Z6 are selected from the group consisting of hydrogen, an aliphatic, araliphatic and aromatic moiety; or E is -0-T-(OH)b, T is a straight or branched chain alkylene of 1 to 18 carbon atoms, cycloalkylene of 5 to 18 carbon atoms, cycloalkenylene of 5 to 18 carbon atoms, a straight or branched chain alkylene of 1 to 4 carbon atoms substituted by phenyl or by phenyl substituted by one or two alkyl groups of 1 to 4 carbon atoms;

b is 1, 2 or 3 with the proviso that b cannot exceed the number of carbon atoms in T, and when b is 2 or 3, each hydroxyl group is attached to a different carbon atoms of T.

?0 E is for example oxyl, hydroxyl, alkoxy, cycloalkoxy or aralkoxy. For instance, E is methoxy, propoxy, cyclohexyloxy or octyloxy.

The present sterically hindered amine stabilizers of component (i) are for example of ?5 -the formula A-R

(A) :Ro1m R

(B) P

0--R'5 E-N
0--R5 (C) n N
E -N
N R7 (D) n (E) [T3]k CO
I

R

RCH2 N CH2R (F) E

M
X
T4 \ N - E
Y (G) n (H) n N(C} COO N - E)3 m T

N Tio N T11 TS
"' >L TS TS TS
N N (J) E E

k N
E-N N~ I T12 N N

T6 (K) ) TS TS

E
e TS R

T XT

n O Ea E-N

E E2 E3 (M) II II

(O) (P) E-N
X
(Q) E-N O
(R) wherein E is oxyl, hydroxyl, alkoxy of 1 to 18 carbon atoms, cycloalkoxy of 5 to 12 carbon atoms or aralkoxy of 7 to 15 carbon atoms, or E is -O-T-(OH)b, T is a straight or branched chain alkylene of 1 to 18 carbon atoms, cycloalkylene of 5 to 18 carbon atoms, cycloalkenylene of 5 to 18 carbon atoms, a straight or branched chain alkylene of 1 to 4 carbon atoms substituted by phenyl or by phenyl substituted by one or two alkyl groups of 1 to 4 carbon atoms;

b is 1, 2 or 3 with the proviso that b cannot exceed the number of carbon atoms in T, and when b is 2 or 3, each hydroxyl group is attached to a different carbon atoms of T;

R is hydrogen or methyl, m is 1 to 4, when m is 1, R2 is hydrogen, C1-C18alkyl or said alkyl optionally interrupted by one or more oxygen atoms, C2-C12alkenyl, C6-C1Oaryl, C7-C18aralkyl, glycidyl, a monovalent acyl radical of an aliphatic,cycloaliphatic or aromatic carboxylic acid, or a carbamic acid, for example an acyl radical of an aliphatic carboxylic acid having 2-18 C atoms, of a cycloaliphatic carboxylic acid having 5-12 C atoms or of an aromatic carboxylic acid having 7-15 C atoms, or -(CH3)3C
(CH)3C
O O
HO 3\ 11 O

(CH3)3C (CH3)3C
X
wherein x is 0 or 1, OI
(CH2)y N N H

wherein y is 2-4;
when m is 2, R2 is C1-C12alkylene, C4-C12alkenylene, xylylene, a divalent acyl radical of an aliphatic, cycloaliphatic, araliphatic or aromatic dicarboxylic acid or of a dicarbamic acid, for example an acyl radical of an aliphatic dicarboxylic acid having 2-18 C atoms, of a cycloaliphatic or aromatic dicarboxylic acid having 8-14 C atoms, or of an aliphatic, cycloaliphatic or aromatic dicarbamic acid having 8-14 C atoms;

O
O
D1 or D3 -C H

C -C

II
N
(CHZ) d H

wherein D, and D2 are independently hydrogen, an alkyl radical containing up to 8 carbon atoms, an aryl or aralkyl radical including 3,5-di-t-butyl-4-hydroxybenzyl radical, D3 is hydrogen, or an alkyl or alkenyl radical containing up to 18 carbon atoms, and d is 0-20;

when m is 3, R2 is a trivalent acyl radical of an aliphatic, unsaturated aliphatic, cycloaliphatic, or aromatic tricarboxylic acid;

when m is 4, R2 is a tetravalent acyl radical of a saturated or unsaturated aliphatic or aromatic tetracarboxylic acid including 1,2,3,4-butanetetracarboxylic acid, 1,2,3,4-but-2-ene-tetracarboxylic, and 1,2,3,5- and 1,2,4,5-pentanetetracarboxylic acid;
pis1,2or3, R3 is hydrogen, C1-C12alkyl, C5-C7cycloalkyl, C7-C9aralkyl, C2-C18alkanoyl, C3-C5alkenoyl or benzoyl;
when pis 1, R4 is hydrogen, C1-C,8alkyl, C5-C7cycloalkyl, C2-C$alkenyl, unsubstituted or substituted by a cyano, carbonyl or carbamide group, aryl, aralkyl, or it is glycidyl, a group of the formula -CH2-CH(OH)-Z or of the formula -CO-Z or -CONH-Z wherein Z is hydrogen, methyl or phenyl; or a group of the formulae N-E

or (CH3)3C - (CH3)3C
O O
HO O

(CH3)3C (CH3)3C

h where h is 0 or 1, R3 and R4 together, when p is 1, can be alkylene of 4 to 6 carbon atoms or 2-oxo-polyalkylene the cyclic acyl radical of an aliphatic or aromatic 1,2- or 1,3-dicarboxylic acid, when p is 2, R4 is a direct bond or is C1-C12alkylene, C6-C12arylene, xylylene, a -CH2CH(OH)-CH2 group or a group -CH2-CH(OH)-CH2-O-X-O-CH2-CH(OH)-CH2- wherein X is C2-C10alkylene, C6-C15arylene or C6-C12cycloalkylene; or, provided that R3 is not alkanoyl, alkenoyl or benzoyl, R4 can also be a divalent acyl radical of an aliphatic, cycloaliphatic or aromatic dicarboxylic acid or dicarbamic acid, or can be the group -CO-; or R4 is N
",-,T-N YN
N
T$ T9 where T8 and T9 are independently hydrogen, alkyl of 1 to 18 carbon atoms, or T8 and T9 together are alkylene of 4 to 6 carbon atoms or 3-oxapentamethylene, for instance T8 and T9 together are 3-oxapentamethylene;

when p is 3, R4 is 2,4,6-triazinyl, n is 1 or 2, when n is 1, R5 and R'5 are independently C,-C12 alkyl, C2-C12 alkenyl, C7-C,2 aralkyl, or R5 is also hydrogen, or R5 and R'5 together are C2-C8alkylene or hydroxyalkylene or C4-C22acyloxyalkylene;

when n is 2, R5 and R'5 together are (-CH2)2C(CH2-)2;

R6 is hydrogen, C1-C12alkyl, allyl, benzyl, glycidyl or C2-C6alkoxyalkyl;
when n is 1, R7 is hydrogen, C1-C12alkyl, C3-C5alkenyl, C7-C9aralkyl, C5-C7cycloalkyl, C2-C4hydroxyalkyl, C2-C6alkoxyalkyl, C6-C10aryl, glycidyl, a group of the formula -(CH2)t-COO-Q
or of the formula -(CH2)t-O-CO-Q wherein t is 1 or 2, and Q is C1-C4alkyl or phenyl; or when n is 2, R7 is C2-C12alkylene, C6-C12arylene, a group -CH2CH(OH)-CH2-O-X-O-CH2-CH(OH)-CH2- wherein X is C2-C10alkylene, C6-C15arylene or C6-C12cycloalkylene, or a group -CH2CH(OZ')CH2-(OCH2-CH(OZ')CH2)2- wherein Z' is hydrogen, C1-C18alkyl, allyl, benzyl, C2-C12alkanoyl or benzoyl;

01 is -N(R8)- or -0-; E7 is C1-C3 alkylene, the group -CH2-CH(R9)-O- wherein R9 is hydrogen, methyl or phenyl, the group -(CH2)3-NH- or a direct bond;

R10 is hydrogen or C1-C18 alkyl, R8 is hydrogen, C1-C18alkyl, C5-C7cycloalkyl, C12aralkyl, cyanoethyl, C6-C10aryl, the group -CH2-CH(R9)-OH wherein R9 has the meaning defined above; a group of the formula E -N

or a group of the formula R

N

wherein G4 is C2-C6alkylene or C6-C12arylene; or R8 is a group -E7-CO-NH-CH2-OR10;

Formula F denotes a recurring structural unit of a polymer where T3 is ethylene or 1,2-propylene, is the repeating structural unit derived from an alpha-olefin copolymer with an alkyl acrylate or methacrylate; for example a copolymer of ethylene and ethyl acrylate, and where k is 2 to 100;

T4 has the same meaning as R4 when p is 1 or 2, T5 is methyl, T5 is methyl or ethyl, or T5 and T6 together are tetramethylene or pentamethylene, for instance T5 and T6 are each methyl, M and Y are independently methylene or carbonyl, and T4 is ethylene where n is 2;
T7 is the same as R7, and T7 is for example octamethylene where n is 2, T,0 and Tõ are independently alkylene of 2 to 12 carbon atoms, or Tõ is N

-T~ II
NYN
N
Tg T9 T12 is piperazinyl, -NR,,-(CH2)d-NRt1- or - NR(CH2) - N(-2J N[(-Hz) = N] H
a b c f where R11 is the same as R3 or is also N-E

a, b and c are independently 2 or 3, and f is 0 or 1, for instance a and c are each 3, b is 2 and f is 1; and e is 2, 3 or 4, for example 4;

T13 is the same as R2 with the proviso that T13 cannot be hydrogen when n is 1;
E1 and E2, being different, each are -CO- or -N(E5)- where E5 is hydrogen, C1-alkyl or C4-C22 alkoxycarbonylalkyl, for instance E1 is -CO- and E2 is -N(E5)-, E3 is hydrogen, alkyl of 1 to 30 carbon atoms, phenyl, naphthyl, said phenyl or said naphthyl substituted by chlorine or by alkyl of 1 to 4 carbon atoms, or phenylalkyl of 7 to 12 carbon atoms, or said phenylalkyl substituted by alkyl of 1 to 4 carbon atoms, E4 is hydrogen, alkyl of 1 to 30 carbon atoms, phenyl, naphthyl or phenylalkyl of 7 to 12 carbon atoms, or E3 and E4 together are polymethylene of 4 to 17 carbon atoms, or said polymethylene substituted by up to four alkyl groups of 1 to 4 carbon atoms, for example methyl, E6 is an aliphatic or aromatic tetravalent radical, R2 of formula (N) is a previously defined when m is 1;

G1 a direct bond, C1-C12 alkylene, phenylene or -NH-G'-NH wherein Gis C1-C12 alkylene; or wherein the hindered amine compound is a compound of the formula I, II, III, IV, V, VI, VII, VIII, IX, X or XI

.5 E4 X N
y N N N~
O (I) E. I

NYN NCO (O

Y
/
R

Y~ NY,N~A E3 N N N (~) Y O

y\R/N NRNN NR
11-1 yN ~ II

N N N N

E2 A A E3 (N) 0\ R1 O
Ea R

y~ N N~O~ 0,,N__ y R3 )055~' 11 R6 i l R3 N N N~ N

E3 (V) N
O 1V~0R1 Ea E1 RS RS
~NN y -"r )i "", X N N\Ra N N NT N

E1 Ea E2 A A E3 (VI) N
O tN R
3 Ea E1 E 0 X N~O ,OY~N~X

N\\ N N,N

EZ A A

~N (VII) O ;tNO~R1 R1 E3 a y I Ea T N N

N N t El E O (VIII) VN

R y TY~N~N E3 I II
N
N N
E y O
E1 ax) E
z N ~R E2 Rl /N
O y I Ea I O

E4;- E1 E4 El RS RS (X) Y N N ~N j 1411, Y

N , N N N
Y Y
T T
O~, R1 I

(XI) Y N N O O N N Y

N N N N
T T
wherein E,, E2, E3 and E4 are independently alkyl of 1 to 4 carbon atoms, or E, and E2 are independently alkyl of 1 to 4 carbon atoms and E3 and E4 taken together are pentamethylene, or E, and E2; and E3 and E4 each taken together are pentamethylene, R, is alkyl of 1 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, a bicyclic or tricyclic hydrocarbon radical of 7 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms or said aryl substituted by one to three alkyl of 1 to 8 carbon atoms, R2 is hydrogen or a linear or branched chain alkyl of 1 to 12 carbon atoms, R3 is alkylene of 1 to 8 carbon atoms, or R3 is -CO-, -CO-R4-, -CONR2-, or -CO-R4 is alkylene of 1 to 8 carbon atoms, R5 is hydrogen, a linear or branched chain alkyl of 1 to 12 carbon atoms, or El E2 N - O

or when R4 is ethylene, two R5 methyl substituents can be linked by a direct bond so that the triazine bridging group -N(R5)-R4-N(R5)- is a piperazin-1,4-diyl moiety, R6 is alkylene of 2 to 8 carbon atoms or R6 is \

with the proviso that Y is not -OH when R6 is the structure depicted above, A is -0- or -NR,-where R7 is hydrogen, a straight or branched chain alkyl of 1 to 12 carbon atoms, or R7 is El E2 N-O

T is phenoxy, phenoxy substituted by one or two alkyl groups of 1 to 4 carbon atoms, alkoxy of 1 to 8 carbon atoms or -N(R2)2 with the stipulation that R2 is not hydrogen, or T is E1 . E2 X is -NH2i -NCO, -OH, -0-glycidyl, or -NHNH2, and Y is -OH, -NH2, -NHR2 where R2 is not hydrogen; or Y is -NCO, -COOH, oxiranyl, glycidyl, or -Si(OR2)3; or the combination R3-Y- is -CH2CH(OH)R2 where R2 is alkyl or said alkyl interrupted by one to four oxygen atoms, or R3-Y- is -CH2OR2i or wherein the hindered amine compound is a mixture of N,N',N"'-tris{2,4-bis[(1-hydrocarbyloxy-2,2,6,6-tetramethyl piperidin-4-yl)alkylamino]-s-triazin-6-yl}-3,3'-ethylenediiminodipropylamine;
N,N',N"-tris{2,4-bis[(1-hydrocarbyloxy-2,2,6,6-tetramethylpiperidin-4-yl)alkylamino]-s-triazin-6-yl}-3,3'-ethylenediiminodipropylamine, and bridged derivatives as described by formulas I, II, IIA and III

R1NH-CH2CH2CH2NR2CH2CH2NR3CH2CH2CH2NHR4 (I) T-E,-T, (II) T-E, (IIA) G-E,-G,-E,-G2 (III) where in the tetraamine of formula I

R, and R2 are the s-triazine moiety E; and one of R3 and R4 is the s-triazine moiety E
with the other of R3 or R4 being hydrogen, E is J,' N N
R5-~ N N N" R5 N N
i OR OR
R is methyl, propyl, cyclohexyl or octyl, for instance cyclohexyl, R5 is alkyl of 1 to 12 carbon atoms, for example n-butyl, where in the compound of formula 11 or IIA when R is propyl, cyclohexyl or octyl, T and T, are each a tetraamine substituted by R,-R4 as is defined for formula I, where (1) one of the s-triazine moieties E in each tetraamine is replaced by the group E, which forms a bridge between two tetraamines T and T1, E, is N N N N
"

R'j~ 5 ---, N Rs\ N 1\N N.~ Rs ~N N/Rs N N AN
OR O L O OR

or (2) the group E, can have both termini in the same tetraamine T as in formula IIA
where two of the E moieties of the tetraamine are replaced by one E, group, or (3) all three s-triazine substituents of tetraamine T can be E, such that one E, links T
and T, and a second E, has both termini in tetraamine T, L is propanediyl, cyclohexanediyl or octanediyl;
where in the compound of formula III

G, G, and G2 are each tetraamines substituted by R,-R4 as defined for formula I, except that G and G2 each have one of the s-triazine moieties E replaced by E,, and G, has two of the triazine moieties E replaced by E,, so that there is a bridge between G
and G, and a second bridge between G, and G2;

which mixture is prepared by reacting two to four equivalents of 2,4-bis[(1-hydrocarbyl-oxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine with one equivalent of N, N'-bis(3-aminopropyl)ethylenediam ine;

or the hindered amine is a compound of the formula IIIb A iN'~-N R12 N N~--A
N IIN I NYN

H3C i ^H3 I (IIIb) ?H2 ?H2 n in which the index n ranges from 1 to 15;
R12 is C2-C12alkylene, C4-C12alkenylene, C5-C7cycloalkylene, C5-C7cycloalkylene-di(C1-C4alkylene), C1-C4alkylenedi(C5-C7cycloalkylene), phenylenedi(C1-C4alkylene) or C4-C12alkylene interrupted by 1,4-piperazinediyl, -0- or >N-X1 with X1 being C1-C12acyl or -(C1-C12alkoxy)carbonyl or having one of the definitions of R14 given below except hydrogen;
or R12 is a group of the formula (lb') or (Ic');

-CH2 i H-CH2 (lb') O

C=0 x2 O O
-< >-xi- (Icy) with m being 2 or 3, X2 being C1-C18alkyl, C5-C12cycloalkyl which is unsubstituted or substituted by 1, 2 or C1-C4alkyl; phenyl which is unsubstituted or substituted by 1, 2 or 3 C1-C4alkyl or C1-C4alkoxy; C7-C9phenylalkyl which is unsubstituted or substituted on the phenyl by 1, 2 or 3 C1-C4alkyl; and the radicals X3 being independently of one another C2-C12alkylene;

R13, R14 and R15, which are identical or different, are hydrogen, C1-C18alkyl, C12cycloalkyl which is unsubstituted or substituted by 1, 2 or 3 C1-C4alkyl;
C3-C18alkenyl, phenyl which is unsubstituted or substituted by 1, 2 or 3 C1-C4alkyl or C1-C4alkoxy; C7-C9phenylalkyl which is unsubstituted or substituted on the phenyl by 1, 2 or 3 C1-C4alkyl;
tetrahydrofurfuryl or C2-C4alkyl which is substituted in the 2, 3 or 4 position by -OH, C1-C8alkoxy, di(C1-C4alkyl)amino or a group of the formula (le');

/-\
Y/N (le') with Y being -0-, -CH2-, -CH2CH2- or >N-CH3, or -N(R14)(R15) is additionally a group of the formula (le');
the radicals A are independently of one another -OR13, -N(R14)(R15) or a group of the formula (llld);

X N -O-CH2 CH2 CH3 (Illd) X is -0- or >N-R16;

R16 is hydrogen, C1-C18alkyl, C3-C1Salkenyl, C5-C12cycloalkyl which is unsubstituted or substituted by 1, 2 or 3 C1-C4alkyl; C7-C9phenylalkyl which is unsubstituted or substituted on the phenyl by 1, 2 or 3 C1-C4alkyl; tetrahydrofurfuryl, a group of the formula (Illf), N -O-CH2 CH2 CH3 (11 if) or C2-C4alkyl which is substituted in the 2, 3 or 4 position by -OH, C1-C8alkoxy, di(C1-C4alkyl)amino or a group of the formula (le');

R11 has one of the definitions given for R16; and the radicals B have independently of one another one of the definitions given for A.
Alkyl is straight or branched and is for example methyl, ethyl, n-propyl, n-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl or n-octadecyl.

Cycloalkyl groups include cyclopentyl and cyclohexyl; typical cycloalkenyl groups include cyclohexenyl; while typical aralkyl groups include benzyl, alpha-methyl-benzyl, alpha,alpha-dimethylbenzyl or phenethyl.
If R2 is a monovalent acyl radical of a carboxylic acid, it is for example an acyl radical of acetic acid, stearic acid, salicyclic acid, benzoic acid or 0-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid.

If R2 is a divalent acyl radical of a dicarboxylic acid, it is for example an acyl radical of oxalic acid, adipic acid, succinic acid, suberic acid, sebacic acid, phthalic acid dibutylmalonic acid, dibenzylmalonic acid or butyl-(3,5-di-tert-butyl-4-hydropxybenzyl)-malonic acid, or bicycloheptenedicarboxylic acid, with succinates, sebacates, phthalates and isophthalates being specific examples.

If R2 is a divalent acyl radical of a dicarbamic acid, it is for example an acyl radical of hexamethylenedicarbamic acid or of 2,4-toluylenedicarbamic acid.

Hindered alkoxyamine stabilizers of component (i) are well known in the art, also known as N-alkoxy hindered amines and NOR hindered amines or NOR hindered amine light stabilizers or NOR HALS.
They are disclosed for example in U.S. Pat. Nos. 5,004,770, 5,204,473, 5,096,950, 5,300,544, 5,112,890, 5,124,378, 5,145,893, 5,216,156, 5,844,026, 6,117,995, 6,271,377, 6,392,041, 6,376,584, 6,599,963, and 6,472,456.

U.S. Pat. Nos. 6,271,377, 6,392,041, and 6,376,584, cited above disclose hindered -hydroxyalkoxyamine stabilizers. For the purposes of this invention, the hindered hydoxyalkoxyamine stabilizers are considered a subset of the hindered alkoxyamine stabilizers and are part of present component (i) . Hindered hydroxyalkoxyamirie stabilizers are also known as N-hydroxyalkoxy hindered amines, or NORol HALS.
Suitable hindered amines of component (i) include for example:

NOR 1 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine;
NOR2 bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;

NOR3 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxyethylamino-s-triazine;
NOR4 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine;
NOR5 1-(2-hydroxy-2-methylpropoxy)-4-hydroxy-2,2,6,6-tetramethylpiperidine;
NO R6 1-(2-hyd roxy-2-methylpropoxy)-4-oxo-2,2,6,6-tetramethylpiperidine;
NO R7 1-(2-hyd roxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethyl-piperidine;
NOR8 bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;
NOR9 bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) adipate;
NOR10 2,4-bis{N-[1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl]-N-butylamino}-6-(2-hydroxyethylamino)-s-triazine;
NOR11 the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine with N,N'-bis(3-aminopropyl)ethylenediamine) [CAS Reg.
No. 191680-81-6]; and NOR12 the compound of formula N N
N

N~NrN-(cH2)6 i '-IT-N-(CH2)6 N i YN
NN NVN
N-C,Hy IN
N

N
O
n in which n is from 1 to 15;
Compound NOR12 is disclosed in example 2 of U.S. Patent No. 6,117,995.
NOR1 3 is bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) adipate.

The stabilizers of component (i) are advantageously contained in the composition of the invention in an amount from about 0.05% to about 20% by weight based on the polymer substrate (a); for example from about 0.1% to about 10% by weight; for example from about 0.2% to about 8% by weight; for instance from about 0.5% to about 3% by weight. For example, the stabilizers of component (i) are present from about 0.05% to about 15%, from about 0.05% to about 10%, from about 0.05% to about 8%, from about 0.05% to about 5% or from about 0.05% to about 3% by weight based on the weight of substrate (a).
For example, the stabilizers of component (i) are present from about 0.1 % to about 20%, from about 0.2 to about 20%, from about 0.5 to about 20% or from about 1 % to about 20% by weight based on the weight of substrate (a).

Conventional Flame Retardants of Component (ii) Oganohalogen flame retardants are for example:

Chloroalkyl phosphate esters (ANTIBLAZE AB-1 00, Albright & Wilson; FYROL FR-2, Akzo Nobel), tris(2-chloroethyl)phosphate polybrominated diphenyl oxide (DE-60F, Great Lakes Corp.), decabromodiphenyl oxide (DBDPO; SAYTEX 102E), tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate (PB 370 , FMC Corp.), tris(2,3-dibromopropyl)phosphate tris(2,3-dichloropropyl)phosphate, - chlorendic acid, tetrachlorophthalic acid, tetrabromophthalic acid, bis-(N,N'-hydroxyethyl)tetrachlorphenylene diamine, poly-R-chloroethyl triphosponate mixture tetrabromobisphenol A bis(2,3-dibromopropyl) ether (PE68), brominated epoxy resin, ethylene-bis(tetrabromophthalimide) (SAYTEX BT-93), bis(hexachlorocyclopentadieno)cyclooctane (DECLORANE PLUS ), chlorinated paraffins, octabromodiphenyl ether, hexachlorocyclopentadiene derivatives, 1,2-bis(tribromophenoxy)ethane (FF680), tetrabromo-bisphenol A (SAYTEX RB100), ethylene bis-(dibromo-norbornanedicarboximide) (SAYTEX BN-451), bis-(hexachlorocyclopentadieno) cyclooctane, PTFE
tris-(2,3-dibromopropyl)-isocyanurate, and ethylene-bis-tetrabromophthalimide.
The phosphorus containing flame retardants are for example:
Tetraphenyl resorcinol diphosphite (FYROLFLE)e RDP, Akzo Nobel), triphenyl phosphate, trioctyl phosphate, tricresyl phosphate, tetrakis(hydroxymethyl)phosphonium sulfide, diethyl-N,N-bis(2-hydroxyethyl)-aminomethyl phosphonate, hydroxyalkyl esters of phosphorus acids, ammonium polyphosphate (APP) or (HOSTAFLAM AP750), resorcinol diphosphate oligomer (RDP), phosphazene flame retardants and ethylenediamine diphosphate (EDAP).
-Isocyanurate flame retardants include polyisocyanurate, esters of isocyanuric acid and isocyanurates. For example, an hydroxyalkyl isocyanurate such as tris-(2-hyd roxyethyl) isocyan u rate, tris(hydroxymethyl)isocyanurate, tris(3-hydroxy-n-proyl) isocyanu rate or triglycidyl isocyanurate.

The melamine based flame retardants are for example:
melamine cyanurate, melamine borate, melamine phosphates, melamine polyphosphates and melamine pyrophosphates.

Boric acid may be included as a flame retardant.

The halogenated flame retardants useful in the present invention may be selected from organic aromatic halogenated compounds such as halogenated benzenes, biphenyls, phenols, ethers or esters thereof, bisphenols, diphenyloxides, aromatic carboxylic acids or polyacids, anhydrides, amides or imides thereof; organic cycloaliphatic or polycycloaliphatic halogenated compounds; and organic aliphatic halogenated compounds such as halogenated paraffins, oligo- or polymers, alkylphosphates or alkylisocyanurates. These components are largely known in the art, see e.g. US patents Nos. 4,579,906 (e.g. col. 3, lines 30-41), 5,393,812; see also Plastics Additives Handbook, Ed. by H.
Zweifel, 5th Ed., Hanser Publ., Munich 2001, pp. 681-698.

The phosphazene flame retardants are well known in the art. They are disclosed for example in EP1104766, JP07292233, DE19828541, DE1988536, JP11263885, U.S. Pat.
Nos. 4,107,108, 4,108,805 and 4,079,035 and 6,265,599.

PTFE, polytetrafluoroethylene (for example Teflon 6C; E. I. Du Pont), may be -advantageously added to the present compositions as an additional flame retardant.
Component (ii) is advantageously contained in the composition of the invention in an amount from about 0.5% to about 45% by weight of the polymeric substrate (a);
for instance about 3% to about 40%; for example about 5% to about 35% by weight of component (a).
For example, component (ii) is employed from about 0.5% to about 10% by weight, from about 1 % to about 10%, from about 3% to about 10% or from about 5% to about 10% by weight, based on the weight of the polymeric substrate. For example, component (ii) is employed from about 0.5% to about 8%, from about 0.5% to about 6%, from about 0.5% to about 5%, or from about 0.5% to about 3% by weight, based on the weight of the polymeric substrate.

The ratio (parts by weight) of component (i) to component (ii) is for example between about 1:5 to about 1:200, for instance from about 1:50 to about 1:100, or about 1:10 to about 1:25. For example the ratio of component (i) to component (ii) is from about 1:10 to about 1:200, from about 1:25 to about 1:200, from about 1:50 to about 1:200 or from about 1:100 to about 1:200. For example, the weight ratio of component (i) to component (ii) is from about 1:5 to about 1:100, from about 1:5 to about 1:50, from about 1:5 to about 1:25, or from about 1:5 to about 1:10.

The amount of component (ii) used also depends on the effectiveness of the specific compound(s), the polymer and the specific application type.

Acid Scavengers of Component (iii) Acid scavengers are for example hydrotalcites and amorphous basic aluminum magnesium carbonates, such as those described in U.S. Pat. Nos. 4,427,816, 5,106,898 and 5,234,981, the relevant disclosures of which are hereby incorporated by reference.
Hydrotalcite is also known as hycite or DHT4A.

Hydrotalcites are natural or synthetic. The natural hydrotalcite is held to possess a structure Mg6Al2(OH)16C03. 4 H20-A typical empirical formula of a synthetic hydrotalcite is AI2Mg4.3bOH1t,36CO3(1.67) = x Examples of the synthetic product include: Mg0.7Al0.3(OH)2(CO3)o.15 ' 0.54 H2O, Mg4.5AI2(OH)13CO3 = 3.5 H2O and Mg4.2AI(OH)12.4CO3.

The acid scavengers are present in the polymeric compositions at a level of about 0.1 % to about 1.0% by weight, based on the weight of component (a). For instance, the present acid scavengers are present from about 0.2% to about to about 0.8% or from about 0.4% to about 0.6% by weight, based on the weight of component (a). For example, the present acid scavengers are present from about 0.1 % to about 0.8%, from about 0.1 % to about 0.6%, from about 0.1 % to about 0.4% or from about 0.1 % to about 0.2%
by weight based on the weight of component (a). For instance, the present acid scavengers are present from about 0.2% to about 1.0%, from about 0.4% to about 1.0%, from about 0.6% to about 1.0% or from about 0.8% to about 1.0% by weight based on the weight of component (a).
The acid scavengers aid the present compositions in color, odor and stability.
The compositions of the present invention are useful for many applications, for example outdoor applications, including the following:

Thermoplastic (poly)olefins Paintable thermoplastic (poly)olefins Polypropylene molded articles Polyethylene film Thermoplastic elastomers with other costabilizers Grease-filled wire and cable insulation Coatings Coatings over plastic substrates Polyolefin tanks or containers containing chemicals Polyolefin films with an antifog agent Polyolefin films with IR thermal fillers such as hydrotalcites, e.g. DHT4A
- Polyolef in films with an antistatic agent Flame-resistant molded polypropylene articles Flame-resistant molded thermoplastic polyolefins Flame-resistant polyethylene film Pre-formed films for lamination to plastic substrates Electronic appliances Containers, boxes, bins for storage and transportation Automotive applications e.g. dashboard, back board Furniture e.g. stadium seats, public seats Roofing sheets Roofing membranes Flooring materials Liners Profiles, for example window and door profiles .5 Geomembranes Awning fabrics Banner films Upholstery Drapery Carpeting Tents, tarpaulins Surgical gowns, caps and other hospital applications Fabrics Ropes Nets Tire cords Parachutes The compositions of the present invention are useful in textile laminates and as coatings of substrates as described in U.S. Pat. Nos. 6,235,658 and 6,251,995, the relevant disclosures of which are hereby incorporated by reference.

The materials containing the stabilizers described herein can be used for the -production of moldings, rotomolded articles, injection molded articles, blow molded articles, mono- and multilayer films, extruded profiles, surface coatings and the like.

The resulting stabilized compositions of the invention may optionally also contain various conventional additives, for example in amounts from about 0.01 to about 10%, for instance from about 0.025 to about 4%, for example from about 0.1 to about 2%
by weight of component (a), such as the materials listed below, or mixtures thereof.

1. Antioxidants 1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-di-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-bu-tyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-((x-methylcyclohexyl)-4,6-dimethyl-phenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-meth-oxymethylphenol, nonyiphenols which are linear or branched in the side chains, for example, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1'-methylundec-1'-yl)phenol, 2,4-dimethyl-6-(1'-methylheptadec- 1'-yl)phenol, 2,4-dimethyl-6-(1'-methyltridec-1'-yl)phenol and mixtures there-of.

1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctyl-thiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4-nonylphenol.
1.3. Hydroguinones and alkylated hydroguinones, for example 2,6-di-tert-butyl-4-methoxy-phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octade-cyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-bu-tyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis-(3,5-di-tert-butyl-4-hy-droxyphenyl) adipate.

1.4. Tocopherols, for example a-tocopherol, R-tocopherol, y-tocopherol, 5-tocopherol and mixtures thereof (Vitamin E).

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

1.6. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(a-methylcyclohexyl)-phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4-me-thylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butylphe-nol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(a-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis[6-(a,a-dimethylbenzyl)-4-nonylphenol], 4,4'-methylenebis-(2,6-di-tert-butyl phenol), 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-methyl-phenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydr-oxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, 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-di methyl-2-hydroxyph enyl) butane, 2,2-bis-(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis-(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7. 0-. N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxydi-benzyl 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-hydroxy-benzyl)sulfide, isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

1.8. Hydroxybenzvlated malonates, for example dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hy-droxybenzyl)-malonate, di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)-malonate, di-dodecylmercaptoethyl-2,2-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1,1,3,3-te-tramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9. Aromatic hvdroxvbenzyl compounds, for example 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxy-benzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetrame--thylbenzene, 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-hydroxy-anilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-tri-azine, 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-(3,5-di-tert-butyl-4-hydroxyben-zyl)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)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)-hexahydro-1,3,5-triazine, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)iso-cyanurate.

1.11. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphospho-nate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl-4-hy-droxybenzylphosphonate, dioctadecyl -5-te rt-b utyl-4- hydroxy-3-methyl ben zylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.
1.12. Acvlaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.13. Esters of R-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono-or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethy-lene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hy-droxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylol-propane, 4-hydroxymethyl-1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14. Esters of 13-(5-tert-butyl-4-hydroxy-3-methylphenvl)propionic acid with mono- or poly-hydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanedi-ol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis-(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethyl-olpropane, 4-hydroxymethyl-l -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.15. Esters of 0-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono-or polyhydric -alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, tri-ethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N, N'-bis(hydroxyethyl)ox-amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy-droxymethyl-1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane.
1.16. Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alco-hols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanu rate, N,N'-bis(hydroxyethyl)ox-amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy-droxymethyl-1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17. Amides of 5-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g. N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamide, N, N'-bis(3,5-di-tert-butyl-4-hydroxy-phenylpropionyl)trimethylenediamide, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazide, N,N'-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide (Nau-gard XL-1 supplied by Uniroyal).

1.18. Ascorbic acid (vitamin C) 1.19. Aminic antioxidants, for example N,N'-di-isopropyl-p-phenylenediamine, N,N'-di-sec-bu-tyl-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicy-clohexyl-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'-phe-nyl-p-phenylenediamine, N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenlenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyidiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-l -naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, for example p,p'-di-tert-octyldiphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4'-diaminodiphenylmethane, 4,4'--diaminodiphenylmethane, N,N,N',N'-tetramethyl-4,4'-diaminodiphenylmethane, 1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis[4-(1',3'-dimethylbutyl)phenyl]amine, tert-octylated N-phenyl-1 -naphthylamine, a mixture of mono-and dialkylated tert-butyl/tert-octyldiphenylamines, a mixture of mono- and dialkylated nonyldiphenylamines, a mixture of mono- and dialkylated dodecyldiphenylamines, a mixture of mono- and dialkylated isopropyl/isohexyldiphenylamines, a mixture of mono-and dialkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, a mixture of mono- and dialkylated tert-butyl/tert-octylphenothiazines, a mixture of mono- and dialkylated tert-octyl-phenothiazines, N-allylphenothiazin, 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 light stabilizers 2.1. 2-(2-Hydroxyphenyl)-2H-benzotriazoles, for example known commercial hydroxyphenyl-2H-benzotriazoles and benzotriazoles as disclosed in, United States Patent Nos. 3,004,896;
3,055,896; 3,072,585; 3,074,910; 3,189,615; 3,218,332; 3,230,194; 4,127,586;
4,226,763; 4,275,004; 4,278,589; 4,315,848; 4,347,180; 4,383,863; 4,675,352;
4,681,905, 4,853,471; 5,268,450; 5,278,314; 5,280,124; 5,319,091; 5,410,071;
5,436,349; 5,516,914; 5,554,760; 5,563,242; 5,574,166; 5,607,987, 5,977,219 and 6,166,218 such as 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-t-octylphenyl)-2H-benzotriazole, 5-chloro-2-(3,5-di-t-butyl-2-hydroxyphenyl)-2H-benzotriazole, 5-chloro-2-(3-t-butyl-2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(3-sec-butyl-5-t-butyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(3,5-bis-a-cumyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(3-t-butyl-2-hydroxy-5-(2-(w-hydroxy-octa-(ethyleneoxy)carbonyl-ethyl)-, phenyl)-2H-benzotriazole, 2-(3-dodecyl-2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(3-t-butyl-2-hydroxy-5-(2-octyloxycarbonyl)ethylphenyl)-2H-benzotriazole, dodecylated 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(3-t-butyl-2-hydroxy-5-(2-octyloxycarbonylethyl)phenyl)-5-chloro-2H-benzotriazole, 2-(3-tert-butyl-5-(2-(2-ethylhexyloxy)-carbonylethyl)-2-hydroxyphenyl)-5-chloro-2H-benzotriazole, 2-(3-t-butyl-2-hydroxy-5-(2-methoxycarbonylethyl)phenyl)-5-chloro-2H-benzotriazole, 2-(3-t-butyl-2--hydroxy-5-(2-methoxycarbonylethyl) phenyl)-2H-benzotriazole, 2-(3-t-butyl-5-(2-(2-ethylhexyloxy)carbonylethyl)-2-hydroxyphenyl)-2H-benzotriazole, 2-(3-t-butyl-2-hydroxy-5-(2-isooctyloxycarbonylethyl)phenyl-2H-benzotriazole, 2,2'-methylene-bis(4-t-octyl-(6-2H-benzotriazol-2-yl)phenol), 2-(2-hydroxy-3-a-cumyl-5-t-octylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3-t-octyl-5-a-cumylphenyl)-2H-benzotriazole, 5-fluoro-2-(2-hydroxy-3,5-di-(x-cumyl-phenyl)-2H-benzotriazole, 5-chloro-2-(2-hydroxy-3,5-di-a-cumylphenyl)-2H-benzotriazole, 5-chloro-2-(2-hydroxy-3-a-cumyl-5-t-octylphenyl)-2H-benzotriazole, 2-(3-t-butyl-2-hydroxy-5-(2-isooctyloxycarbonylethyl)phenyl)-5-chloro-2H-benzotriazole, 5-trifluoromethyl-2-.(2-hydroxy-3-a-cumyl-5-t-octylphenyl)-2H-benzotriazole, 5-trifluoromethyl -2-(2-hydroxy-5-t-octylphenyl)-2H-benzotriazole, 5-trifluoromethyl-2-(2-hydroxy-3,5-di-t-octylphenyl)-2H-benzotriazole, methyl 3-(5-trifluoromethyl-2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyhydrocinnamate, 5-butylsulfonyl-2-(2-hydroxy-3-a-cumyl-5-t-octylphenyl)-2H-benzotriazole, 5-trifluoromethyl-2-(2-hydroxy-3-a-cumyl-5-t-butylphenyl)-2H-benzotriazole, 5-trifluoromethyl-2-(2-hydroxy-3,5-di-t-butylphenyl)-2H-benzotriazole, 5-trifluoromethyl-2-(2-hydroxy-3,5-di-a-cumylphenyl)-2H-benzotriazole, 5-butylsulfonyl-2-(2-hydroxy-3,5-di-t-butylphenyl)-2H-benzotriazole and 5-phenylsulfonyl-2-(2-hydroxy-3,5-di-t-butylphenyl)-2H-benzotriazole.
2.2.2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyl-oxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivatives.
2.3. Esters of substituted and unsubstituted benzoic acids, as for example 4-tertbutyl-phenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis(4-tert-butylben-zoyl) resorcinol, benzoyl resorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzo-ate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxyben-zoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

2.4. Acrylates, for example ethyl a-cyano-3,(3-diphenylacrylate, isooctyl a-cyano-(3,(3-diphe-nylacrylate, methyl a-carbomethoxycinnamate, methyl a-cyano-3-methyl-p-methoxy-cinna-mate, butyl a-cyano-R-methyl-p-methoxy-cinnamate, methyl a-carbomethoxy-p-methoxycin-namate and N-([3-carbomethoxy-[3-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis-[4-(1,1,3,3-tetramethyl-butyl)phenol], such as the 1:1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, nickel salts of the monoalkyl esters, e.g. the methyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid, nickel complexes of ketoximes, e.g. of 2-hydroxy-4-methylphe-nyl undecylketoxime, nickel complexes of 1 -phenyl-4-lauroyl-5-hydroxypyrazole, with or with-out additional ligands.

2.6. Further 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)sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, linear or cyclic condensates of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-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-butane-tetracarboxylate, 1,1'-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-.5 2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decan-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, linear or cyclic condensates of N,N'-bis-(2,2,6,6-tetramethyl-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-triazine and 1,2-bis(3-aminopropylamino)ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetram ethyl- 1 , 3,8-triazaspi ro[4.5]decane-2,4-dion e, 3-dodecyl-1 -(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione, 3-dodecyl-l -(1,2,2,6,6-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(2,2,6,6-tetramethyl-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensation product of 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-6]); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimid, N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimid, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1 -oxa-3,8-diaza-4-oxospiro [4,5]decane and epichlorohydrin, 1, 1 -bis(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl)-2-(4-methoxyphenyl)ethene, N,N'-bis-formyl-N,N'-bis(2,2,6,6-tetramethyl-4--piperidyl)hexamethylenediamine, diester of 4-methoxy-methylene-malonic acid with 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3-oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane, reaction product of maleic acid anhydride-a-olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine or 1,2,2,6,6-pentamethyl-4-aminopiperidine.

2.7. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy-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'-ethoxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide, mixtures of o- and p-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.

2.8. Tris-aryl-o-hydroxyphenyl-s-triazines, for example known commercial tris-aryl-o-hydroxyphenyl-s-triazines and triazines as disclosed in, WO 96/28431 and United States Patent Nos. 3,843,371; 4,619,956; 4,740,542; 5,096,489; 5,106,891; 5,298,067;
5,300,414; 5,354,794; 5,461,151; 5,476,937; 5,489,503; 5,543,518; 5,556,973;
5,597,854; 5,681,955; 5,726,309; 5,736,597; 5,942,626; 5,959,008; 5,998,116;
6,013,704; 6,060,543; 6,187,919; 6,242,598 and 6,255,483, for example 4,6-bis-(2,4-dimethylphenyl)-2-(2-hydroxy-4-octyloxyphenyl)-s-triazine, Cyasorb 1164, Cytec Corp, 4,6-bis-(2,4-dimethylphenyl)-2-(2,4-dihydroxyphenyl)-s-triazine, 2,4-bis(2,4-dihydroxyphenyl)-6-(4-chlorophenyl)-s-triazine, 2,4-bis[2-hydroxy-4-(2-hydroxyethoxy)phenyl]-6-(4-chlorophenyl)-s-triazine, 2,4-bis[2-hydroxy-4-(2-hydroxy-4-(2-hydroxyethoxy)phenyl]-6-(2,4-dimethylphenyl)-s-triazine, 2,4-bis[2-hydroxy-4-(2-hydroxyethoxy)phenyl]-6-(4-bromophenyl)-s-triazine, 2,4-bis[2-hydroxy-4-(2-acetoxyethoxy)phenyl]-6-(4-chlorophenyl)-s-triazine, 2,4-bis(2,4-dihydroxyphenyl)-6-(2,4-dimethylphenyl)-s-triazine, 2,4-bis(4-biphenylyl)-6-(2-hydroxy-4-octyloxycarbonylethylideneoxyphenyl)-s-triazine, 2-phenyl-4-[2-hydroxy-4-(3-sec-b utyloxy-2-hyd roxyp ropyloxy)phenyl]-6-[2-hydroxy-4-(3-sec-amyloxy-2-hyd roxypropyloxy)-phenyl]-s-triazine, 2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-benzyloxy-2-hydroxy-propyloxy)phenyl]-s-triazine, 2,4-bis(2-hydroxy-4-n-butyloxyphenyl)-6-(2,4-di-n-butyloxy-phenyl)-s-triazine, 2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-nonyloxy"-2-hydroxy-propyloxy)-5-a-cumylphenyl]-s-triazine (* denotes a mixture of octyloxy, nonyloxy and decyloxy groups), methylenebis-{2,4-bis(2,4-dimethylphenyl)-6-[2-hydroxy-4-(3-butyloxy-2-hydroxypropoxy)phenyl]-s-triazine}, methylene bridged dimer mixture bridged in the 3:5', 5:5' and 3:3' positions in a 5:4:1 ratio, 2,4,6-tris(2-hydroxy-4-isooctyloxycarbonylisopropylidene-oxyphenyl)-s-triazine, 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-hexyloxy-5-a-cumyl--phenyl)-s-triazine, 2-(2,4,6-trimethylphenyl)-4,6-bis[2-hydroxy-4-(3-butyloxy-2-hydroxy-propyloxy)phenyl]-s-triazine, 2,4,6-tris[2-hydroxy-4-(3-sec-butyloxy-2-hydroxypropyloxy)-phenyl]-s-triazine, mixture of 4,6-bis-(2,4-dimethylphenyl)-2-(2-hydroxy-4-(3-dodecyloxy-2-hydroxypropoxy)-phenyl)-s-triazine and 4,6-bis-(2,4-dimethylphenyl)-2-(2-hydroxy-4-(3-tridecyloxy-2-hydroxypropoxy)-phenyl)-s-triazine, Tinuvin 400, Ciba Specialty Chemicals Corp., 4,6-bis-(2,4-dimethylphenyl)-2-(2-hydroxy-4-(3-(2-ethylhexyloxy)-2-hydroxypropoxy)-phenyl)-s-triazine and 4,6-diphenyl-2-(4-hexyloxy-2-hydroxyphenyl)-s-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-hydroxyphenylpropionyl) hydrazine, 3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyl dihydrazide, N, N'-bis(salicyl-oyl)oxalyl dihydrazide, N,N'-bis(salicyloyl)thiopropionyl dihydrazide.

.5 4. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phos-phite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, diisodecyloxypentaerythritol diphos-phite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tris(tert-butyl-phenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butyl-phenyl) 4,4'-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz-[d,g]-1,3,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-di-benz[d,g]-1,3,2-dioxaphosphocin, 2,2',2"-nitrilo[triethyltris(3,3',5,5'-tetra-tert-butyl-1,1'-biphe-nyl-2,2'-diyl)phosphite], 2-ethylhexyl(3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl)phosphite, 5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)-1,3,2-dioxaphosphirane.
Specific examples are the following phosphites:
Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos 168, Ciba-Geigy), tris(nonylphenyl) phosphite, (CH3)3C C(CH3)3 (CH3)3C C(CH3)3 (A) H3C-CH P-F P-O-CH2CH2 N (g) O O

(CH3)3C C (CH3)3 C(CH3)3 (CH3)3C 3 (CH3)3C C(CH3)3 0 (C) P-O-CH2CH(C4H9)CH2CH3 O
(CH3)3C
C(CH3)3 (CH3)3C 0-P P-0 C(CH3)3 p p - (D) C(CH3)3 (CH3)3C
C(CH3)3 (CH3)3C-H3C - O-P\ P-O CH3 (E) O O
C(CH3)3 (CH3)3C

(F) H C-O-P P-O-C H O P-OCH2CH3 G
37 18 18 37 I ( ) :KO O H3C

5. Hydroxylamines, for example, N,N-dibenzylhydroxylamine, N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine, N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine, N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine, N-hexadecyl-N-octadecylhydrox-ylamine, N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

6. Nitrones, for example, N-benzyl-alpha-phenyl-nitrone, N-ethyl-alpha-methyl-nitrone, N-oc-tyl-alpha-heptyl-nitrone, N-Iauryl-alpha-undecyl-nitrone, N-tetradecyl-alpha-tridcyl-nitrone, N-hexadecyl-alpha-pentadecyl-nitrone, N-octadecyl-alpha-heptadecyl-nitrone, N-hexadecyl-al-pha-heptadecyl-nitrone, N-ocatadecyl-alpha-pentadecyl-nitrone, N-heptadecyl-alpha-hepta-decyl-nitrone, N-octadecyl-alpha-hexadecyl-nitrone, nitrone derived from N,N-dialkylhydroxyl-amine derived from hydrogenated tallow amine.
7. Thiosynergists, for example, dilauryl thiodipropionate or distearyl thiodipropionate.

8. Peroxide scavengers, for example esters of R-thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or the zinc salt of 2-mercapto-benzimidazole, zinc dibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritol tetrakis(0-dodecyl mercapto)propionate.

9. Polvamide stabilizers, for example, copper salts in combination with iodides and/or phos-phorus compounds and salts of divalent manganese.
10. Basic co-stabilizers, for example, melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids for example calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate or zink pyrocatecholate.

11. Nucleating agents, for example, inorganic substances such as talcum, metal oxides such as titanium dioxide or magnesium oxide, phosphates, carbonates or sulfates of, for example, 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).
Specific examples are 1,3:2,4-bis(3',4'-dimethylbenzylidene)sorbitol, 1,3:2,4-di(paramethyldibenzyli-dene)sorbitol, and 1,3:2,4-di(benzylidene)sorbitol.

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

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

.5 14. Benzofuranones and indolinones, for example those disclosed in U.S.
4,325,863;
U.S. 4,338,244; U.S. 5,175,312; U.S. 5,216,052; U.S. 5,252,643; 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-stearoyloxyethoxy)phe-nyl]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-dimethylphe-nyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(2,3-di-methylphenyl)-5,7-di-tert-butyl-benzofuran-2-one.

15. Amine oxides, for example amine oxide derivatives as disclosed in U.S.
Patent Nos.
5,844,029 and 5,880,191, didecyl methyl amine oxide, tridecyl amine oxide, tridodecyl amine oxide and trihexadecyl amine oxide. U.S. Patent Nos. 5,844,029 and 5,880,191 disclose the use of saturated hydrocarbon amine oxides towards the stabilization of thermoplastic resins.
It is disclosed that the thermoplastic compositions may further contain a stabilizer or mixture of stabilizers selected from phenolic antioxidants, hindered amine light stabilizers, ultraviolet light absorbers, organic phosphorus compounds, alkaline metal salts of fatty acids and thiosynergists. The co-use of amine oxides with other stabilizers towards stabilizing polyolefins is not exemplified.

- Specific examples of additives are phenolic antioxidants (item 1 of the list), further sterically hindered amines (item 2.6 of the list), light stabilizers of the benzotriazole and/or o-hydroxyphenyltriazine class (items 2.1 and 2.8 of the list), phosphites and phosphonites (item 4 of the list) and peroxide-destroying compounds (item 5.) of the list.

Additional specific examples of additives (stabilizers) which are benzofuran-2-ones, such as described, for example, in US-A-4,325,863, US-A-4,338,244 or US-A-5,175,312.
The instant composition can additionally contain another UV absorber selected from the group consisting of the s-triazines, the oxanilides, the hydroxybenzophenones, benzoates and the a-cyanoacrylates. Particularly, the instant composition may additionally contain an effective stabilizing amount of at least one other 2-hydroxyphenyl-2H-benzo-triazole; another tris-aryl-s-triazine; or hindered amine or mixtures thereof.
For example, additional components are selected from pigments, dyes, plasticizers, antioxidants, .5 thixotropic agents, levelling assistants, basic costabilizers, further light stabilizers like UV
absorbers and/or sterically hindered amines, metal passivators, metal oxides, organophosphorus compounds, hydroxylamines, and mixtures thereof, especially pigments, phenolic antioxidants, calcium stearate, zinc stearate, UV absorbers of the 2-(2'-hydroxyphenyl)benzotriazole and 2-(2-hydroxyphenyl)-1,3,5-triazine classes, and sterically hindered amines.

The additives of the invention and optional further components may be added to the polymer material individually or mixed with one another. If desired, the individual components can be mixed with one another before incorporation into the polymer for example by dry blending, compaction or in the melt. Subject of the invention therefore is also a flame retardant additive combination comprising (i) at least one sterically hindered amine stabilizer and (ii) at least one conventional flame retardant selected from the group consisting of the organohalogen, phosphorus containing, isocyanurate and melamine based flame retardants and (iii) at least one acid scavenger.

Conveniently, the additives of above components (i) , (ii) and (iii) and possibly further additives as described above may be dry blended and then extruded, for instance in a twin screw extruder at 180-220 C, with or without nitrogen atmosphere. The material thus obtained may be further processed according to known methods. The surface of the articles formed do not show any loss of gloss or any kind of roughness.

Further, the instant invention pertains to a process for imparting light stability and flame retardancy to an organic polymeric substrate, which process comprises adding to said polymeric substrate an effective flame retarding amount of a synergistic mixture of (i) at least one sterically hindered amine stabilizer, (ii) at least one conventional flame retardant selected from the group consisting of the organohalogen, phosphorus containing, isocyanurate and melamine based flame retardants and (iii) at least one acid scavenger.

The incorporation of the additives of the invention and optional further components into the polymer is carried out by known methods such as dry blending in the form of a powder, or wet mixing in the form of solutions, dispersions or suspensions for example in an inert solvent, water or oil. The additives of the invention and optional further additives may be incorporated, for example, before or after molding or also by applying the dissolved or dispersed additve or additive mixture to the polymer material, with or without subsequent evaporation of the solvent or the suspension/dispersion agent. They may be added directly into the processing apparatus (e.g. extruders, internal mixers, etc), e.g. as a dry mixture or powder or as solution or dispersion or suspension or melt.

The incorporation can be carried out in any heatable container equipped with a stirrer, e.g. in a closed apparatus such as a kneader, mixer or stirred vessel. The incorporation is for -example carried out in an extruder or in a kneader. It is immaterial whether processing takes place in an inert atmosphere or in the presence of oxygen.

The addition of the additive or additive blend to the polymer can be carried out in all customary mixing machines in which the polymer is melted and mixed with the additives.
Suitable machines are known to those skilled in the art. They are predominantly mixers, kneaders and extruders.

The process is for instance carried out in an extruder by introducing the additive during processing.

Specific examples of suitable processing machines are single-screw extruders, contrarotating and corotating twin-screw extruders, planetary-gear extruders, ring extruders or cokneaders. It is also possible to use processing machines provided with at least one gas removal compartment to which a vacuum can be applied.

Suitable extruders and kneaders are described, for example, in Handbuch der Kunststoffextrusion, Vol. 1 Grundlagen, Editors F. Hensen, W. Knappe, H.
Potente, 1989, pp.
3-7, ISBN:3-446-14339-4 (Vol. 2 Extrusionsanlagen 1986, ISBN 3-446-14329-7).

For example, the screw length is 1-60 screw diameters, for example 35-48 screw diameters. The rotational speed of the screw is for instance 10-600 rotations per minute (rpm), for example 25-300 rpm.

The maximum throughput is dependent on the screw diameter, the rotational speed and the driving force. The process of the present invention can also be carried out at a level lower than maximum throughput by varying the parameters mentioned or employing weighing machines delivering dosage amounts.

If a plurality of components are added, these can be premixed or added individually.
The additives of the invention and optional further additives can also be sprayed onto -the polymer material. They are able to dilute other additives (for example the conventional additives indicated above) or their melts so that they can be sprayed also together with these additives onto the material. Addition by spraying during the deactivation of the polymerization catalysts is particularly advantageous; in this case, the steam evolved may be used for deactivation of the catalyst. In the case of spherically polymerized polyolef ins it may, for example, be advantageous to apply the additives of the invention, optionally together with other additives, by spraying.
The additives of the invention and optional further additives can also be added to the polymer in the form of a masterbatch ("concentrate") which contains the components in a concentration of, for example, about 1 % to about 40%, for example about 2% to about 20 %
by weight incorporated in a polymer. The polymer must not be necessarily of identical structure than the polymer where the additives are added finally. In such operations, the polymer can be used in the form of powder, granules, solutions, suspensions or in the form .5 of latices.

Incorporation can take place prior to or during the shaping operation. The materials containing the additives of the invention described herein are for example used for the production of molded articles, for example rotomolded articles, injection molded articles, profiles and the like. Thus, a molded polymer article made flame retardant by the incorporation of (i) at least one sterically hindered amine stabilizer and (ii) at least one conventional flame retardant selected from the group consisting of the organohalogen, phosphorus containing, isocyanurate and melamine based flame retardants and (iii) at least one acid scavenger is another object of the invention.

It is also contemplated that PTFE, polytetrafluoroethylene (for example Teflon 6C; E.
1. Du Pont), may be advantageously added to the present compositions as an additional -flame retardant It has further unexpectedly been observed that polymer molded articles, which normally comprise large amounts of flame-retardant filler in order to maintain flame retardant properties, may be stabilized against light, heat and oxygen and made flame retardant, by the incorporation therein of present components (i), (ii) and (iii), and the amount of flame-retardant filler necessary is greatly reduced or even totally eliminated. The polymer molded articles are for example polyolefin molded articles, for example thin-section articles. The flame-retardant filler is typically magnesium hydroxide.

The thin-section polyolef in molded articles advantageously comprise present components (i), (ii) and (iii). The polyolefin molded articles of this invention, with reduced levels of flame-retardant filler or no flame-retardant filler, maintain flame retardancy and have improved physical properties.
.5 The polyolefin molded articles of this invention may be used for example as roofing membranes, siding, window profiles and moldings. Such molded articles are for example about 5 mil to about 100 mil thick, for example about 20 mil to about 100 mil thick, for instance about 10 mil to about 80 mil, for example about 40 mil to about 100 mil thick. The polyolefin is in particular thermoplastic polyolefin (TPO). The molded articles of this invention exhibit better physical properties than the state of the art formulations, as exhibited by mechanical properties such as tensile strength, elongation resistance and crack resistance.

The effective flame retarding amount of component (B) is that needed to show flame retarding efficacy as measured by one of the standard methods used to assess flame retardancy. These include the NFPA 701 Standard Methods of Fire Tests for Flame-Resistant Textiles and Films, 1989 and 1996 editions; the UL 94 Test for Flammability of Plastic Materials for Parts in Devices and Appliances, 5th Edition, October 29, 1996; Limiting Oxygen Index (LOI), ASTM D-2863; and Cone Calorimetry, ASTM E-1354. Ratings according to the UL 94 V test are as compiled in the following table:
Rating Afterflame Burning Burn to time drips Clamp V-0 <10s no no V-1 < 30 s no no V-2 < 30 s yes no Fail < 30 s yes Fail > 30 s no Coadditives found particularly useful for use with the instant combination of components (i), (ii) and (iii) in flame retardant compositions are as follows:
UV absorbers:

2-(2-hydroxy-3,5-di-a-cumylphenyl)-2H-benzotriazole, (TINUVIN 234, Ciba Specialty Chemicals Corp.);
2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, (TINUVIN P, Ciba Specialty Chemicals Corp.);
5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole, (TINUVIN
327, Ciba Specialty Chemicals Corp.);
2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole, (TINUVIN 328, Ciba Specialty Chemicals Corp.);
2-(2-hydroxy-3-a-cumyl-5-tert-octylphenyl)-2H-benzotriazole, (TINUVIN 928, Ciba Specialty Chemicals Corp.);
2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, (TINUVIN 120, Ciba Specialty Chemicals Corp.);
2-hydroxy-4-n-octyloxybenzophenone, (CHIMASSORB 81, Ciba Specialty Chemicals Corp.);
2,4-bis(2,4-dimethyphenyl)-6-(2-hydroxy-4-octyloxyphenyl)-s-triazine, (CYASORB

1164, Cytec).

The following examples are meant for illustrative purposes only and are not to be construed to limit the scope of this invention in any manner whatsoever. Where given, room temperature depicts a temperature in the range 20-25 C. Percentages are by weight of the polymer substrate unless otherwise indicated.

Abbreviations:
-v parts by volume w parts by weight 'Hnmr nuclear magnetic resonance (NMR) of 'H
m/z mass spectrometry (atomic units) amu molecular weight in g/mol (= atomic units) PP polypropylene PE polyethylene PE-LD low density polyethylene (LDPE) Test Methods NFPA 701 Standard Methods of Fire Tests for Flame-Resistant Textiles and Films, 1989 and 1996 editions;
UL 94 Test for Flammability of Plastic Materials for Parts in Devices and Appliances, 5th Edition, October 29, 1996;

Limiting Oxygen Index (LOI), ASTM D-2863;
Cone Calorimetry, ASTM E-1 or ASTM E 1354;
ASTM D 2633-82, burn test.

Test compounds Hindered amines of present component (i):

NOR1 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine;
NOR2 bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;
NOR3 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxyethylamino-s-triazine;
NOR4 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine;
NOR5 1-(2-hydroxy-2-methylpropoxy)-4-hydroxy-2,2,6,6-tetramethylpiperidine;
NOR6 1-(2-hydroxy-2-methylpropoxy)-4-oxo-2,2,6,6-tetramethylpiperidine;
NO R7 1-(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2, 6,6-tetramethyl-piperidine;
NOR8 bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;
NOR9 bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) adipate;
NOR10 2,4-bis{N-[1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl]-N-butylamino}-6-(2-hydroxyethylamino)-s-triazine;

NOR11 the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine with N,N'-bis(3-aminopropyl)ethylenediamine) [CAS Reg.
No. 191680-81-6];

.5 NOR1 1 is represented as a mixture of compounds with main component of the formula R,NH-CH2CH2CH2NR2CH2CH2NR3CH2CH2CH2NHR4 wherein 3 of R,, R2, R3 and R4 are residues of formula CaH% / N-O P

N-- and 1 of R,, R2, R3 and R4 is hydrogen N--( N N-O

(NOR11 is a high molecolar weight compound disclosed in example 3 of U.S.
Pat. No. 5,844,026); and NOR1 2 the compound of formula N N
N
N~N
N-ILz:z-N jl--N-(CH2)6 N i ,-17N-(CH2)s N i II N
N rN NVN

CN N

I
O
in which n is from 1 to 15;

NOR13 bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) adipate.

.5 Conventional flame retardants of component (ii):
DBDPO is decabromodiphenyl oxide, FR1 tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate, (PB 370 , FMC Corp.), FR2 ammonium polyphosphate (APP), FR3 bis(2,3-dibromopropyl) ether of tetrabromobisphenol A (PE68), FR4 ammonium polyphosphate/synergist blend, HOSTAFLAM AP750, FR5 decabromodiphenyl oxide (DBDPO; obtained from Dead Sea Bromine), FR6 ethylene bis-(tetrabromophthalimide), (SAYTEX BT-93), FR7 melamine phosphate, MELAPUR P 46, FR8 ammonium polyphosphate, EXOLIT AP752, FR9 tris-(2,3-dibromopropyl)-isocyanurate, FR10 hexabromocyclododecane, FR11 melamine cyanurate, MELAPUR MC, FR12 melamine borate, FR13 melamine polyphosphate MELAPUR 200 and FR14 melamine pyrophosphate.

Compounds NOR2, NOR7, NOR1 1, NOR1 2 are commercial stabilizers -available from Ciba Specialty Chemicals. MELAPUR products are available from DSM.
Example 1 Flame retardant polypropylene Additives are dry mixed and extruded with polypropylene homopolymer resin with a twin screw (27 mm) extruder at 200 C under nitrogen. Weight percents are based on the polymer. From the pellets, 1.6 mm plaques are prepared by injection molding.
The plaques are tested according to UL 94 protocol after 48 hours conditioning at 25 C and 50% humidity.
Plaques containing 1% by weight NOR11, the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine with N,N'-bis(3-aminopropyl)ethylenediamine), and 14% by weight tris[3-bromo-2,2-bis(bromomethyl)propyl]
phosphate and 0.6% by weight of a present acid scavenger achieve a V-0 rating.
The plaques also exhibit excellent color, odor and stability.
,5 Example 2 Sample preparation: Polymer powder and stabilizers are pre-mixed (Henschel mixer, 800 rpm, room temperature), pigment powder and flame retardant are added as concentrate in PP and homogenized in a drum mixer. Further homogenization and granulation is achieved by extrusion (Collin(D twin screw extruder, max 200 C, 100 rpm).
Subsequently, the mixture is processed into a flat film by means of a single screw extruder (max 200 C, 70 rpm) equipped with a corresponding nozzle (sample dimension 2mm thickness, 10 cm width).
Weathering: Punched samples are exposed to accelerated weathering (Atlas WOM
Ci 65, 0.35W/m2 (at 340nm), 102 min dry, 18 min water spray, 63 C black panel temperature.
The effect of weathering on the surface is assessed in the following manner:
Visual inspection of chalking (chalking indicates decomposition on the surface).
Gloss: Minolta; degradation of surface reduces the reflection of polarized light (60 gloss as defined in DIN 67530).
A E: Color change (according to DIN 6174).
Formulation:
84 parts by weight of polypropylene-ethylene copolymer (Novolen PPG 1022), 15 parts by weight of a PE-based flame retardant masterbatch containing 51% by weight of FR1, 1 part by weight of TiO2 and 0.2 parts by weight of blue pigment (Cromophtal blue 4GNP) 0.4 parts of an NOR selected from NOR1-NOR12 0.1 part present acid scavenger.

Samples containing the combination of flame retardant and sterically hindered amines of the present invention and a present acid scavenger show no chalking, better gloss and distinctly less color change.

.5 Example 3 Fiber grade poly(ethylene terephthalate) (PET) is dry blended with test additives, then melt compounded at 550 F and then pelletized. The polyester pellets are dried at 175 F for 24 hours under vacuum. The dried pellets are extruded into fibers using a Hills laboratory scale fiber extruder at 550 F. Socks are knitted from these fibers and tested for flame retardancy according to NFPA 701 test method.

The fibers containing a compound selected from NOR1-NOR12, a classic flame retardant and a present acid scavenger exhibit excellent flame retardancy.

Example 4 Thermoplastic resins including polypropylene, polyethylene homopolymer, polyolefin copolymer or thermoplastic polyolefins (TPO), high impact polystyrene (HIPS) and ABS are dry blended with test additives and then melt compounded into pellets. The pelletized fully formulated resin is then processed into a useful article such as extrusion into fiber; blown or cast extrusion into film; blow molded into bottles; injection molded into molded articles, -thermoformed into molded articles, extruded into wire and cable housing or rotation molded into hollow articles.

The articles containing a compound selected from NOR1-NOR12, a known conventional flame retardant and a present acid scavenger exhibit excellent flame retardancy when tested by a known standard test method.

Polyethylene wire and cable applications are tested for flame retardancy according to ASTM D-2633-82 burn test method. The materials containing a compound selected from NOR1-NOR12, a conventional flame retardant and a present acid scavenger show excellent flame retardancy.

Example 5 Articles prepared according to Example 4 which additionally contain an organophosphorus stabilizer selected from the group consisting of tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, 2,2',2"-nitrilo[triethyl-tris-(3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl-2,2'-diyl) phosphite], tetrakis(2,4-di-butylphenyl) 4,4'-biphenylenediphosphonite, tris(nonylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythrityl diphosphite, 2,2'-ethylidenebis(2,4-di-tert-butylphenyl) fluorophosphite and 2-butyl-2-ethylpropan-1,3-diyl 2,4,6-tri-tert-butylphenyl phosphite exhibit good flame retardancy properties.

Example 6 Articles prepared according to Example 4 which additionally contain a o-hydroxy-phenyl-2H-benzotriazole, a hydroxyphenyl benzophenone or a o-hydroxyphenyl-s-triazine UV absorber selected from the group consisting of 2-(2-hydroxy-3,5-di-a-cumylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3-a-cumyl-5-tert-octylphenyl)-2H-benzotriazole, 2,4-di-tert-butylphenyl 3,5-di--tert-butyl4-hydroxybenzoate, 2-hydroxy-4-n-octyloxybenzophenone and 2,4-bis(2,4-dimethy-phenyl)-6-(2-hydroxy-4-octyloxyphenyl)-s-triazine exhibit good flame retardancy.

Claims (19)

CLAIMS:

1. A flame retardant polymer composition which comprises (a) an organic polymer substrate and (b) an effective flame retarding amount of a synergistic mixture of (i) at least one sterically hindered amine stabilizer, (ii) tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate and (iii) at least one acid scavenger selected from the group consisting of hydrotalcites, where the stabilizers of component (i) are of the formula where G1 and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z1 and Z2 are each methyl, or Z1 and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is cyclohexyloxy; and where the acid scavengers of component (iii) are present from about 0.1 % to about 1.0% by weight based on component (a).

2. A composition according to claim 1 containing no flame retardant or conventional filler or a flame retardant or conventional filler in an amount less than 3% by weight based on the weight of the polymer component (a).

3. A composition according to claim 1 containing no antimony compounds or antimony compounds in an amount less than 1% by weight based on the weight of component (a).

4. A composition according to any one of claims 1 to 3, in which the polymer component (a) is a thermoplastic polymer.

5. A composition according to any one of claims 1 to 3, in which the polymer component (a) is selected from the group of resins consisting of the polyolefins, the thermoplastic olefins, styrenic polymers and copolymers, ABS
and polymers which contain hetero atoms, double bonds or aromatic rings.

6. A composition according to any one of claims 1 to 3, in which the polymer component (a) is selected from polyethylene, polypropylene or copolymers thereof.

7. A composition according to any one of claims 1 to 6, in which component (i) is a mixture of N,N',N"'-tris{2,4-bis[(1-hydrocarbyloxy-2,2,6,6-tetramethylpiperidin-4-yl)alkylamino]-s-triazin-6-yl}-3,3'-ethylenediiminodipropylamine; N,N',N"'-tris{2,4-bis[(1-hydrocarbyloxy-2,2,6,6-tetramethylpiperidin-4-yl)alkylamino]-s-triazin-6-yl}-3,3'-ethylenediimino-dipropylamine, and bridged derivatives as described by formulas I, II, IIA and III

R1NH-CH2CH2CH2NR2CH2CH2NR3CH2CH2CH2NHR4 (I) T-E1-T1 (II) T-E1 (IIA) G-E1-G1-E1-G2 (III) where in the tetraamine of formula I

R1 and R2 are the s-triazine moiety E; and one of R3 and R4 is the s-triazine moiety E with the other of R3 or R4 being hydrogen, E is R is cyclohexyl, R5 is alkyl of 1 to 12 carbon atoms, where in the compound of formula II or IIA, T and T1 are each a tetraamine substituted by R1-R4 as is defined for formula I, where (1) one of the s-triazine moieties E in each tetraamine is replaced by the group E1 which forms a bridge between two tetraamines T and T1, E1 is (2) the group E1 can have both termini in the same tetraamine T as in formula IIA where two of the E moieties of the tetraamine are replaced by one E1 group, or (3) all three s-triazine substituents of tetraamine T can be E1 such that one E1 links T and T1 and a second E1 has both termini in tetraamine T, L is cyclohexanediyl where in the compound of formula III

G, G1 and G2 are each tetraamines substituted by R1-R4 as defined for formula I, except that G and G2 each have one of the s-triazine moieties E

replaced by E1, and G1 has two of the triazine moieties E replaced by E1, so that there is a bridge between G and G1 and a second bridge between G1 and G2;

which mixture is prepared by reacting two to four equivalents of 2,4-bis[(1-hydrocarbyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine with one equivalent of N,N'-bis(3-aminopropyl)ethylenediamine.

8. A composition according to any one of claims 1 to 6, wherein the stabilizers of component (i) are selected from the group consisting of 1-cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine;
2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxyethylamino-s-triazine;

bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)adipate;
2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine;

and the reaction product of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-chloro-s-triazine with N,N'-bis(3-aminopropyl)ethylenediamine.

9. A composition according to any one of claims 1 to 8, in which the stabilizers of component (i) are present from about 0.05% to about 20% by weight based on the polymer substrate (a).

10. A composition according to any one of claims 1 to 8, in which the stabilizers of component (i) are present from about 0.1 % to about 10% by weight based on the polymer substrate (a).

11. A composition according to any one of claims 1 to 10, in which component (ii) is present in an amount from about 0.5% to about 45% by weight based on the polymeric substrate (a).

12. A composition according to any one of claims 1 to 11, in which the acid scavengers of component (iii) are present from about 0.2% to about 0.8%
by weight based on component (a).

13. A composition according to any one of claims 1 to 12, comprising a further component selected from the group consisting of pigments, dyes, plasticizers, phenolic antioxidants, thixotropic agents, levelling assistants, basic costabilizers, nitrone stabilizers, amine oxide stabilizers, benzofuranone stabilizers, UV absorbers, sterically hindered amines, metal passivators, metal oxides, organophosphorus compounds, hydroxylamines, and mixtures thereof.

14. A composition according to claim 13 in which the further component is selected from the group consisting of phenolic antioxidants, calcium stearate, zinc stearate, phosphite or phosphonite stabilizers, benzofuranone stabilizers, UV
absorbers of the 2-(2'-hydroxyphenyl)benzotriazole or 2-(2-hydroxyphenyl)-1,3,5-triazine classes, and sterically hindered amines.

15. A process for imparting light stability and flame retardancy to an organic polymer substrate, which process comprises adding to said polymer substrate (i) at least one sterically hindered amine stabilizer, (ii) tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate and (iii) at least one acid scavenger selected from the group consisting of hydrotalcites, where the stabilizers of component (i) are of the formula where G1 and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z1 and Z2 are each methyl, or Z1 and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is cyclohexyloxy; and where the acid scavengers of component (iii) are present from about 0.1 % to about 1.0% by weight based on the polymer substrate.

16. A construction article selected from the group consisting of roofing membranes, window profiles, siding and moldings, which comprises a flame retardant polymer composition as defined in any one of claims 1 to 14.

17. A thermoplastic polyolefin article, which comprises a flame retardant polymer composition as defined in any one of claims 1 to 14.

18. A flame retardant additive combination comprising (i) at least one sterically hindered amine stabilizer, (ii) tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate and (iii) at least one acid scavenger selected from the group consisting of hydrotalcites, where the stabilizers of component (i) are of the formula where G1 and G2 are independently alkyl of 1 to 8 carbon atoms or are together pentamethylene, Z1 and Z2 are each methyl, or Z1 and Z2 together form a linking moiety which may additionally be substituted by an ester, ether, amide, amino, carboxy or urethane group, and E is cyclohexyloxy; and where the acid scavengers of component (iii) are present from about 0.1 % to about 1.0% by weight based on component (a).

19. Use of the flame retardant additive combination as defined in claim 18 for imparting light stability and flame retardancy to an organic polymer substrate or molded polymer article.