Flame retardant polymer compositions

1. A flame retardant composition which comprises

a) a thermoplastic polymer substrate and

b) an effective flame retarding amount of a combination of

one or more bismuth compounds selected from the group consisting of bismuth oxychloride, bismuth oxyfluoride, bismuth oxybromide, bismuth oxyiodide and bismuth oxynitrate and

one or more organobromine flame retardants.

2. A composition according to claim 1 where the thermoplastic polymer substrate is selected from the group consisting of polyolefin homopolymers, polyolefin copolymers, thermoplastic olefin, polystyrene, polystyrene copolymers, polycarbonates, polyamides and polyesters.

3. A composition according to claim 1 where the thermoplastic polymer substrate is polypropylene, polyethylene, ethylene/propylene copolymer or thermoplastic olefin.

4. A composition according to claim 1 where said bismuth compounds are present from about 0.5% to about 10% by weight, based on the weight of the thermoplastic polymer substrate.

5. A composition according to claim 1 where said bismuth compounds are present from about 1% to about 7% by weight, based on the weight of the thermoplastic polymer substrate.

6. A composition according to claim 1 where the organobromine flame retardants are present from about 1% to about 40% by weight, based on the weight of the thermoplastic polymer substrate.

7. A composition according to claim 6 where the organobromine flame retardants are present from about 3% to about 25% by weight, based on the weight of the thermoplastic polymer substrate.

8. A composition according to claim 1 where the organobromine flame retardants are selected from the group consisting of

tetrabromobisphenol A (TBBPA), tetrabromophthalate esters, bis(2,3-dibromopropyloxy)tetrabromobisphenol A, brominated carbonate oligomers based on TBBPA, brominated epoxy oligomers based on condensation of TBBPA and epichlorohydrin, copolymers of TBBPA and 1,2-dibromoethane; dibromobenzoic acid, dibromostyrene (DBS) and its derivatives; ethylenebromobistetrabromophthalimide, dibromoneopentyl glycol, dibromocyclooctane, trisbromoneopentanol, tris(tribromophenyl)triazine, 2,3-dibromopropanol, tribromoaniline, tribromophenol, tetrabromocyclopentane, tetrabromobiphenyl ether, tetrabromodipentaerythritol, decabromodiphenyl ether, tetrabromophthalic anhydride, pentabromotoluene, pentabromodiphenyl ether, pentabromodiphenyl oxide, pentabromophenol, pentabromophenyl benzoate, pentabromoethylbenzene, hexabromocyclohexane, hexabromocyclooctane, hexabromocyclodecane, hexabromocyclododecane, hexabromobenzene, hexabromobiphenyl, octabromobiphenyl, octabromodiphenyl oxide, poly(pentabromobenzyl acrylate), octabromodiphenyl ether, decabromodiphenyl ethane, decabromodiphenyl, brominated trimethylphenylindan, tetrabromochlorotoluene, bis(tetrabromophthalimido)ethane, bis(tribromophenoxy)ethane, brominated polystyrene, brominated epoxy oligomer, polypentabromobenzyl acrylate, dibromopropylacrylate, dibromohexachlorocyclopentadienocyclooctane, N′-ethyl(bis)dibromononboranedicarboximide, tetrabrombisphenol S, N′N′-ethylbis(dibromononbornene)dicarboximide, hexachlorocyclopentadieno-bis-(2,3-dibromo-1-propyl)phthalate, brominated phosphates like bis(2,3-dibromopropyl)phosphate and tris(tribromoneopentyl)phosphate and tris(dichlorobromopropyl)phosphite, N,N′-ethylene-bis-(tetrabromophthalimide), tetrabromophthalic acid diol[2-hydroxypropyl-oxy-2-2-hydroxyethyl-ethyltetrabromophthalate], vinylbromide, polypentabromobenzyl acrylate, polybrominated dibenzo-p-dioxins, tris-(2,3-dibromopropyl)-isocyanurate, ethylene-bis-tetrabromophthalimide and tris(2,3-dibromopropyl)phosphate.

9. A composition according to claim 1 where the organobromine flame retardants are selected from the group consisting of

decabromodiphenyl ether,

tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate,

bis(2,3-dibromopropyl ether) of bisphenol A,

tetrabromobisphenol A bis(dibromopropyl ether),

brominated epoxy resin,

ethylene-bis(tetrabromophthalimide),

1,2-bis(tribromophenoxy)ethane,

tetrabromo-bisphenol A,

hexabromocyclododecane,

brominated polystyrene,

decabromodiphenyl ethane,

ethylene bis-(dibromo-norbornanedicarboximide) and

tris-(2,3-dibromopropyl)-isocyanurate.

10. A composition according to claim 1 , further comprising one or more sterically hindered hydrocarbyloxyamine stabilizers.

11. A composition according to claim 10 , further comprising one or more sterically hindered hydrocarbyloxyamine stabilizers 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-hydroxyethyl-amino-s-triazine;

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

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

1-(2-hydroxy-2-methylpropoxy)-4-hydroxy-2,2,6,6-tetramethylpiperidine;

1-(2-hydroxy-2-methylpropoxy)-4-oxo-2,2,6,6-tetramethylpiperidine;

1-(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine;

bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) sebacate;

bis(1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl) adipate;

2,4-bis{N-[1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-yl]-N-butyl-amino}-6-(2-hydroxyethylamino)-s-triazine;

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

where n is from 1 to 15.

12. A composition according to claim 1 , further comprising one or more additional flame retardants selected from the group consisting of phosphorus containing flame retardants and melamine based flame retardants.

13. A composition according to claim 1 , further comprising one or more additional flame retardants selected from the group consisting of

chloroalkyl phosphate esters,

bis(hexachlorocyclopentadieno)cyclooctane,

chlorinated paraffins,

tetraphenyl resorcinol diphosphite,

triphenyl phosphate,

ammonium polyphosphate,

resorcinol diphosphate oligomer,

melamine cyanurate,

melamine borate,

melamine polyphosphate,

melamine phosphate,

melamine pyrophosphate and

ethylenediamine diphosphate.

14. A composition according to claim 1 further comprising one or more additives 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 amine light stabilizers, metal passivators, metal oxides, organophosphorus compounds, lubricants and hydroxylamines.

15. A composition according to claim 1 further comprising one or more additives selected from the group consisting of phenolic antioxidants, calcium stearate, zinc stearate, phosphite or phosphonite stabilizers, benzofuranone stabilizers, 2-(2′-hydroxyphenyl)benzotriazole, 2-(2-hydroxyphenyl)-1,3,5-triazine or benzoate UV absorbers and sterically hindered amine light stabilizers.

16. A composition according to claim 1 , further comprising one or more compounds selected from the group consisting of zinc oxide, zinc borate, antimony oxide, aluminum hydroxide, magnesium hydroxide, aluminum trihydroxide, alumina hydrate, alumina trihydrate, magnesium oxide, magnesium chloride, talcum, alumina magnesium, calcium silicate, sodium silicate, zeolite, sodium carbonate, calcium carbonate, ammonium molybdate, iron oxide, copper oxide, zinc phosphate, zinc chloride, clay, sodium dihydrogen phosphate, tin, vanadium compounds, molybdenum and zinc.

17. A composition according to claim 1 , further comprising zinc oxide.