Thermoplastic resin compositions containing mixtures of cyclic phosphazenes and phosphoric acid esters

1. A flame retardant thermoplastic resin composition comprising:

(A) about 45 to 95 parts by weight of a polycarbonate resin;

(B) about 1 to 50 parts by weight of a rubber modified vinyl-grafted copolymer prepared by graft-polymerizing (b 1 ) about 5 to 95 parts by weight of a monomer mixture of about 50 to 95% by weight of at least one of styrene, α-methylstyrene, halogen-substituted styrene, alkyl-substituted styrene, C 1-8 methacrylic acid alkyl ester, C 1-8 acrylic acid alkyl ester, or a mixture thereof and about 5 to 50% by weight of acrylonitrile, methacrylonitrile, C 1-8 methacrylic acid alkyl ester, C 1-8 acrylic acid alkyl ester, maleic acid anhydride, or C 1-4 alkyl- or phenyl N-substituted malcimide onto (b 2 ) about 5 to 95 parts by weight of a rubber polymer wherein the rubber polymer is butadiene rubber, acryl rubber, ethylene-propylene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, isoprene rubber, copolymer of ethylene-propylene-diene (FPDM), polyorganosiloxane-polyalkyl (meth)acrylate rubber or a mixture thereof;

(C) about 0 to 50 parts by weight of a vinyl copolymer polymerized with (c 1 ) about 50 to 95% by weight of at least one of styrene, α-methylstyrene, halogen- or alkyl-substituted styrene, C 1-8 methacrylic acid alkyl ester, or C 1-8 acrylic acid alkyl ester and (c 2 ) about 5 to 50% by weight of at least one of acrylonitrile, methacrylonitrile, C 1-8 methacrylic acid alkyl ester, C 1-8 acrylic acid alkyl ester, maleic acid anhydride, and C 1-4 alkyl-maleimide or phenyl N-substituted maleimide;

(D) about 1 to 30 parts by weight of a phosphorous mixture, as a flame retardant, per 100 parts by weight of (A)+(B)+(C), of (d 1 ) about 1 to 50% by weight of a cyclic phosphazene represented by the following formula;

where R 1 is alkyl, aryl, alkyl substituted aryl, aralkyl, alkoxy, aryloxy, amino or hydroxyl, k and m are an integer from 1 to 10, R 2 is dioxyarylene group of C 6-30 or a derivative thereof, and n is 0 or an integer representing the number of repeating unit and the average value of n in the mixture of the phosphazene compound is 0.3 to 3; and

(d 2 ) about 99 to 50% by weight of a phosphoric acid ester represented by the following formula;

where R 3 , R 4 , R 6 and R 7 are a C 6-20 aryl group or an alkyl-substituted C 6-20 aryl group, respectively; R 5 is a C 6-30 arylene group or an alkyl-substituted C 6-30 arylene group; and l means the number of repeating unit and the average value of l in the phosphate mixture is 0 to 3; and

(F) about 0.05 to 5.0 parts by weight of a fluorinated polyolefin resin with average particle size of about 0.05 to 1000 μm and density of about 1.2 to 2.3 g/cm 3 , per 100 parts by weight of (A)+(B)+(C).

2. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein said cyclic phosphazene has a linear structure or a structure with a branched chain at the main chain.

3. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein R 1 is phenoxy and R 2 is a derivative from catechol, resorcinol, hydroquinone, or the bisphenylenediol represented by the following formula:

where Y is alkylene of C 1-5 , alkylidene of C 1-5 , cycloalkylidene of C 5-6 , S or SO 2 , and z is 0 or 1.

4. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein said R 3 , R 4 , R 6 and R 7 are a phenyl group or an alkyl-substituted phenyl group where the alkyl is selected from the group consisting of methyl, ethyl, isopropyl and t-butyl, and R 5 is a derivative from resorcinol, hydroquinone, or bisphenol-A.

5. A molded article produced from the flame retardant thermoplastic resin composition as defined in claim 1 .

6. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein said R 3 , R 4 , R 6 and R 7 are a phenyl group or an alkyl-substituted phenyl group where the alkyl is methyl, ethyl, isopropyl or t-butyl.

7. The flame retardant thermoplastic resin composition as defined in claim 6 , wherein said R 3 , R 4 , R 6 and R 7 are an alkyl-substituted phenyl group where the alkyl is methyl, ethyl, isopropyl or t-butyl.

8. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein R 5 is a derivative from resorcinol, hydroquinone, or bisphenol-A.

9. A molded article produced from the flame retardant thermoplastic resin composition as defined in claim 2 .

10. A molded article produced from the flame retardant thermoplastic resin composition as defined in claim 3 .

11. A molded article produced from the flame retardant thermoplastic resin composition as defined in claim 4 .