Flame retardant thermoplastic resin composition

1. A flame retardant thermoplastic resin composition comprising:

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

(B) 1 to 50 parts by weight of a rubber modified vinyl-grafted copolymer prepared by graft-polymerizing (b 1 ) 5 to 95% by weight of a monomer mixture of 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, C 1-8 acrylic acid alkyl ester, or a mixture thereof and 5 to 50% by weight of acrylonitrile, methacylonitrile, 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 maleimide onto (b 2 ) 5 to 95% by weight of a rubber polymer selected from the group consisting of butadiene rubber, acryl rubber, ethylene-propylene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, isoprene rubber, copolymer of ethylene-propylene-diene (EPDM), polyorganosiloxane-polyalkyl (meta)acrylate rubber complex and a mixture thereof;

(C) 0 to 50 parts by weight of a vinyl copolymer prepared from (c 1 ) 40 to 95% by weight of at least one of styrene, α-methyl styrene, halogen or alkyl substituted styrene, C 1-8 methacrylic acid alkyl ester, or C 1-8 acrylic acid alkyl ester and (c 2 ) 5 to 60% 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, or C 1-4 alkyl or phenyl N-substituted maleimide;

(D) 1˜30 parts by weight of a mixture of organic phosphorous compounds (d 1 ) 1˜50% by weight of a cyclic oligomeric phosphazene compound represented by the following Formula (II) and (d 2 ) 99˜50% by weight of an oligomeric phosphoric acid ester compound represented by the following Formula (IV), per 100 parts by weight of the sum of (A), (B) and (C): and

wherein R 1 is alkyl, aryl, alkyl substituted aryl, aralkyl, alkoxy, aryloxy, amino, or hydroxyl or alkoxy substituted with alkyl, aryl, amino, or hydroxy group or aryloxy substituted with alkyl, aryl, amino, or hydroxy group; k and m are an integer from 0 to 10; R 2 is C 6-30 dioxyaryl or alkyl substituted C 6-30 dioxyaryl derivative; and l is a degree of polymerization and the average value of l is from 0.3 to 3;

wherein R 3 , R 4 , R 5 and R 6 are independently a C 6-20 aryl group or an alkyl-substituted C 6-20 aryl group, respectively, and n is an integer from 1 to 5 representing the number of repeating units and the average value of n in the oligomeric phosphoric acid ester is 1 to 3;

(E) 0.05 to 5.0 parts by weight of a fluorinated polyolefin resin per 100 parts by weight of(A)+(B)+(C).

2. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein said cyclic oligomeric phosphazene compound has a linear structure.

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 (III):

wherein 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 5 and R 6 are phenyl, or naphthyl groups.

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

6. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein said R 3 , R 4 , R 5 and R 6 are a respectively alkyl-substituted phenyl in which alkyl is methyl, ethyl, isopropyl, or t-butyl.

7. The flame retardant thermoplastic resin composition as defined in claim 1 , wherein said fluorinated polyolefin resin has an average particle size of 0.05 to 1,000 μm and a density of 1.2 to 2.3 g/cm 3 .