Symmetric cyclic phosphonate compound, method of preparing the same and flame retardant styrenic resin composition including the same

1. A flame retardant styrenic resin composition comprising:

about 100 parts by weight of a base resin comprising (A) a styrenic resin and (B) a polyphenylene ether resin; and

about 0.5 to about 50 parts by weight of (C) a symmetric cyclic phosphonate compound represented by the following Formula 1 or a combination thereof;

wherein R 1 and R 2 are each independently hydrogen or C 1 -C 6 alkyl.

2. The flame retardant styrenic resin composition of claim 1 , wherein said base resin comprises about 60 to about 99% by weight of said styrenic resin (A) and about 1 to about 40% by weight of said polyphenylene ether resin (B) , based on the total weight of the base resin comprising (A)+(B).

3. The flame retardant styrenic resin composition of claim 1 , further comprising about 0.1 to about 40 parts by weight of (D) an aromatic phosphate ester compound, (E) a phosphate compound or a combination thereof, based on about 100 parts by weight of said base resin (A)+(B).

4. The flame retardant styrenic resin composition of claim 3 , wherein said aromatic phosphate ester compound (D) has a structure represented by the following Formula 4:

wherein R 3 , R 4 and R 5 are each independently hydrogen or C 1 -C 4 alkyl; X is C 6 -C 20 aryl or alkyl-substituted C 6 -C 20 aryl derivative from resorcinol, hydroquinol or bisphenol-A; and n is an integer of 0 to 4.

5. The flame retardant styrenic resin composition of claim 3 , wherein said phosphate compound (E) has a structure represented by the following Formula 5:

wherein R 1 and R 2 are each independently hydrogen or C 1 -C 4 alkyl; M is a metal selected from the group consisting of Al, Mg, K, Zn and Ca; and n is an integer of 1 to 3.

6. The flame retardant styrenic resin composition of claim 1 , further comprising less than or equal to about 30 parts by weight of an additive selected from the group consisting of heat stabilizers, anti-drip agents, anti-oxidants, compatibilizers, light stabilizers, plasticizers, pigments, dyes, inorganic additives and combinations thereof, based on about 100 parts by weight of said base resin (A)+(B).

7. The flame retardant styrenic resin composition of claim 1 , wherein said symmetric cyclic phosphonate compound is represented by the following Formula I-1:

wherein Et is ethyl and t-Bu is tert-butyl.

8. The flame retardant styrenic resin composition of claim 2 , wherein the base resin comprises about 65 to about 90% by weight of the styrenic resin and about 10 to about 35% by weight of the polyphenylene ether resin, based on the total weight of the base resin comprising (A)+(B).

9. The flame retardant styrenic resin composition of claim 8 , wherein the base resin comprises about 70 to about 85% by weight of the styrenic resin and about 15 to about 30% by weight of the polyphenylene ether resin, based on the total weight of the base resin comprising (A)+(B).

10. The flame retardant styrenic resin composition of claim 1 , wherein the styrenic resin comprises a rubber modified aromatic vinyl resin.

11. The flame retardant styrenic resin composition of claim 1 , comprising the symmetric cyclic phosphonate compound in an amount of about 1 to about 40 parts by weight, based on about 100 parts by weight of the base resin (A)+(B).

12. The flame retardant styrenic resin composition of claim 11 , comprising the symmetric cyclic phosphonate compound in an amount of about 2.5 to about 35 parts by weight, based on about 100 parts by weight of the base resin (A)+(B).

13. An article formed of a composition according to claim 1 .

14. The flame retardant styrenic resin composition of claim 1 , wherein R 1 and R 2 are each independently C 1 -C 6 alkyl.