Flame retardant polymer composition

1. A molding composition comprising:

about 40 to 95 parts by weight of a rubber modified vinyl aromatic resin;

about 5 to 60 parts by weight of a polyphenylene ether resin; and

about 0.1 to about 30 parts by weight of a cyclic phosphonate ester compound, represented by Formula (I):

wherein R 1 , R 2 and R 4 are independently C 2 -C 10 alkyl group; R 3 is ethyl; m and n are independently 0, 1 or 2; and (m+n) is 1 or 2.

2. The molding composition of claim 1 , wherein m is 1 or 2.

3. The molding composition of claim 1 , wherein the rubber modified polystyrene resin comprises:

a styrene-containing graft copolymer resin;

and a vinyl resin, wherein the vinyl resin optionally comprises rubber.

4. The molding composition of claim 3 , wherein the styrene-containing graft copolymer resin comprises a rubber from about 10 to about 60 parts by weight and a styrene-acrylonitrile copolymer from about 40 to about 90 parts by weight grafted on the rubber.

5. The molding composition of claim 3 , wherein the vinyl resin comprises about 0.1 to about 20 parts by weight of rubber selected from the group consisting of a butadiene rubber, an isoprene rubber, a copolymer of butadiene and styrene, an alkyl acrylate rubber, and combinations thereof.

6. The molding composition of claim 1 , wherein the polyphenylene ether resin is poly(2,6-dimethyl-1,4-phenylene)ether.

7. The molding composition of claim 1 , further comprising an aromatic phosphate ester.

8. The molding composition of claim 7 , wherein the aromatic phosphate ester is about 0 to about 20 parts by weight based on the rubber modified polystyrene resin, polyphenylene ether resin, and the cyclic phosphonate ester totaling 100 parts by weight of the molding composition.

9. The molding composition of claim 7 , wherein the aromatic phosphate ester is

wherein each R is independently hydrogen or C 1-4 alkyl;

X is derived from a compound comprising two hydroxyaryl groups; and n is 0 to 4.

10. The molding composition of claim 9 , wherein the aryl compound comprising two hydroxyaryl groups is selected from the group consisting of resorcinol, hydroquinone, bisphenol-A, and combinations thereof.

11. The molding composition of claim 1 , further comprising a flame retardant, an anti-dripping agent, an impact modifier, a plasticizer, an inorganic filler, a heat stabilizer, an anti-oxidant,a compatibilizer, a light stabilizer, a pigment, a dye, and combinations thereof.

12. A molding composition of claim 1 , formed in a shaped article.

13. A molded article comprising the molding composition of claim 12 , wherein the article has ΔE less than about 0.5 at 270° C.

14. A composition of claim 1 wherein R 3 is ethyl; m and n are independently 0, 1 or 2, and (m+n) is 1 or 2 and R 1 , R 2 and R 4 are independently C 2 -C 10 alkyl group when m=1 and R 1 , R 2 and R 4 are independently butyl, pentyl, hexyl, septyl, octyl, nonyl or decyl group when m=0 and n=1.

15. A composition of claim 1 wherein R 1 , R 2 and R 4 are independently butyl, pentyl, hexyl, septyl, octyl, nonyl or decyl group.

16. A composition comprising:

a rubber-modified aromatic vinyl resin;

a polyphenylene ether resin; and

a phosphate flame retardant component comprising a cyclic alkyl phosphonate ester compound represented by the following Formula (I):

wherein R 3 is ethyl; m and n are independently 0, 1 or 2, and (m+n) is 1 or 2 and R 1 , R 2 and R 4 are independently C 2 -C 10 alkyl group.

17. A composition of claim 16 wherein R 1 , R 2 and R 4 are independently C 2 -C 10 alkyl group when m=1 and R 1 , R 2 and R 4 are independently butyl, pentyl, hexyl, septyl, octyl, nonyl or decyl group when m=0 and n=1.

18. A composition of claim 16 wherein the phosphate flame retardant consists of the cyclic alkyl phosphonate ester of Formula (I).