Flame retardant thermoplastic elastomers

1. A thermoplastic elastomer composition, comprising:

(a) from about 10 to about 60 weight percent, by weight of the composition, of a polyphenylene ether;

(b) from about 10 to about 60 weight percent, by weight of the composition, of a hydrogenated styrenic block copolymer;

(c) from about 5 to about 30 weight percent, by weight of the composition, of at least one solid non-halogen flame retardant selected from the group consisting of organo-phosphinate, melamine polyphosphate, and combinations thereof;

(d) from about 5 to about 40 weight percent, by weight of the composition, of a nucleated olefinic polymer;

(e) from about 1 to about 2 weight percent, by weight of the composition, of 2,2′-methylene-bis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl))-phenol;

(f) from about 1 to about 2 weight percent, by weight of the composition, of Poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]]); and

(g) from about 2 to about 10 weight percent, by weight of the composition, of titanium dioxide pigment.

2. The thermoplastic elastomer composition of claim 1 ,

wherein the hydrogenated styrenic block copolymer has a weight average molecular weight of between about 70,000 and about 160,000 and a ratio of styrenic end-block to olefinic mid-block ranging from about 20/80 to about 40/60,

wherein the composition further comprises plasticizing oil, and

wherein the composition further comprises tackifier.

3. The thermoplastic elastomer composition of claim 1 , wherein the hydrogenated styrenic block copolymer is selected from the group consisting of styrene-ethylene-butylene-styrene block copolymers, styrene-ethylene-propylene-styrene block copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene-butadiene block copolymers, and styrene-ethylene-ethylene-propylene-styrene block copolymers, and combinations of them.

4. The thermoplastic elastomer composition of claim 1 , wherein the polyphenylene ether is unblended or blended with an aromatic vinyl group thermoplastic resin.

5. The thermoplastic elastomer composition of claim 4 , wherein the polyphenylene ether is selected from the group consisting of poly(2,6-dimethyl-1,4-phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-propyl-1,4-phenylene ether), poly(2,6-dipropyl-1,4-phenylene ether), poly(2-ethyl-6-propyl-1,4phenylene ether), poly(2,6-dimethoxy -1,4-phenylene ether), poly(2,6-di(chloro methyl)-1,4-phenylene ether), poly(2,6-di(bromo methyl)-1,4-phenylene ether), poly(2,6-diphenyl-1,4-phenylene ether), poly(2,6-ditoluyl -1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), poly(2,6-dibenzyl-1,4-phenylene ether), poly(2,5-dimethyl-1,4-phenylene ether), and combinations thereof.

6. The thermoplastic elastomer composition of claim 5 , wherein the aromatic vinyl group thermoplastic resin is selected from the group consisting of homopolymers of styrene or its derivatives, copolymers of styrene and p-methyl styrene, copolymers of styrene and alpha-methyl styrene, copolymers of styrene and alpha-methyl-p-methyl styrene, copolymers of styrene and chlorostyrene, copolymers of styrene and bromostyrene, and combinations thereof.

7. The thermoplastic elastomer composition of claim 1 , wherein the solid non-halogen flame retardant is an organo-phosphinate and wherein the composition further comprises polyammonium polyphosphate.

8. The thermoplastic elastomer composition of claim 1 , wherein the nucleated olefinic polymer is nucleated polypropylene homopolymer.

9. The thermoplastic elastomer composition of claim 1 , wherein the composition further comprises one or more additives selected from the group consisting of adhesion promoters; antioxidants; biocides, antibacterials, fungicides, and mildewcides ; anti-fogging agents; anti-static agents; bonding, blowing or foaming agents; dispersants; fillers or extenders; smoke suppresants; expandable char formers; impact modifiers; initiators; lubricants; micas; processing aids; release agents; silanes, titanates or zirconates; slip or anti-blocking agents; stabilizers; stearates; tackifiers; viscosity regulators; waxes; and combinations of them.

10. The thermoplastic elastomer composition of claim 1 in the form of an insulation layer enveloping a protected electrical line or in the form of a jacketing layer enveloping a protected electrical line.

11. A plastic article made from the thermoplastic elastomer composition of claim 1 .

12. The plastic article of claim 11 , wherein the plastic article has a Delta E color variation of less than 1 after 10 days of QUV testing according to ASTM D4587 (UVA, 340 nm, 0.77 watt/m 2 , 60° C. for 8 hours light and 50° C. for 4 hours dark condensation).

13. The plastic article of claim 11 , in the form of an electrical part or an electronic part.

14. A protected electrical line, comprising:

(a) wire or cable having an axial length and

(b) at least one layer of the thermoplastic elastomer composition of claim 1 enveloping the axial length of the wire or cable.

15. The protected electrical line of claim 14 , wherein the protected electrical line has a Delta E color variation of less than 1 after 10 days of QUV testing according to ASTM D4587 (UVA, 340 nm, 0.77 watt/m 2 , 60° C. for 8 hours light and 50° C. for 4 hours dark condensation).

16. The protected electrical line of claim 14 in the form of a wire.

17. The protected electrical line of claim 14 in the form of a cable.