Transparent thermoplastic resin composition and molded article using the same

1. A transparent thermoplastic resin composition comprising:

(A) about 5 to about 40 wt % of an impact-reinforcing agent having a core-shell structure wherein the core is a rubber core including a copolymer of an acrylic-based monomer and a diene-based monomer and the shell consists of an acrylic-based compound grafted on the core,

wherein the acrylic-based compound is methyl(meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, n-butyl(meth)acrylate, hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate, or a combination thereof, and

wherein in the rubber core, the acrylic-based monomer and the diene-based monomer are present in a weight ratio of about 99:1 to about 65:35, and

(B) about 60 to about 95 wt % of an acrylic-based resin.

2. The transparent thermoplastic resin composition of claim 1 , wherein the impact-reinforcing agent (A) includes about 30 to about 80 wt % of the rubber core, and about 20 to about 70 wt % of the shell, wherein the amounts are based on 100 wt % of the impact-reinforcing agent (A).

3. The transparent thermoplastic resin composition of claim 1 , wherein the impact-reinforcing agent (A) has a particle diameter of about 50 to about 500 nm.

4. The transparent thermoplastic resin composition of claim 1 , wherein the impact-reinforcing agent (A) has a glass transition temperature of about −70 to about −55° C.

5. The transparent thermoplastic resin composition of claim 1 , wherein the impact-reinforcing agent (A) has an average refractive index of about 1.474 to about 1.496.

6. The transparent thermoplastic resin composition of claim 1 , wherein the acrylic-based resin (B) has a refractive index of about 1.480 to about 1.495.

7. The transparent thermoplastic resin composition of claim 1 , wherein a refractive index difference between the impact-reinforcing agent (A) and the acrylic-based resin (B) ranges from about 0.001 to about 0.02.

8. The transparent thermoplastic resin composition of claim 1 , wherein the acrylic-based resin (B) has a weight average molecular weight of about 50,000 g/mol to about 200,000 g/mol.

9. The transparent thermoplastic resin composition of claim 1 , wherein the transparent thermoplastic resin composition further comprises:

(C) an impact-reinforcing agent having a core-shell structure wherein an acrylic-based compound is grafted on a rubber core including a copolymer of a C4 to C30 acrylic-based monomer and an aromatic vinyl-based monomer, to form a shell.

10. The transparent thermoplastic resin composition of claim 1 , wherein the (A) impact-reinforcing agent includes a rubber core consisting essentially of the acrylic-based monomer and the diene-based monomer.

11. The transparent thermoplastic resin composition of claim 1 , wherein a molded article formed of the composition has a haze of about 0.5% to about 10% and a transmittance of about 85% to about 95% which are measured at a thickness of about 1.5 to about 2.5 mm.

12. A molded article using the transparent thermoplastic resin composition according to claim 1 .

13. The molded article of claim 12 , wherein the molded article has a haze of about 0.5% to about 10%, and a transmittance of about 85% to about 95% which are measured at a thickness of about 1.5 to about 2.5 mm.

14. The molded article of claim 12 , wherein the molded article comprises a black colorant, and the molded article has an L value of a CIE color coordinate of less than about 28 with reference to black.

15. The molded article of claim 12 , wherein the molded article has a pencil hardness (JIS K 5401) of greater than or equal to HB.

16. The molded article of claim 12 , wherein the molded article has a ΔE value indicating weather resistance of less than or equal to 3 which is measured after about 3000 hours under a SAE J 1960 condition.

17. The molded article of claim 12 , wherein the molded article has a ⅛″ Izod impact strength (ASTM D256) of about 3 to about 12 kgf·cm/cm.