Polycarbonate/polycarbonate-polysiloxane composition

A thermoplastic resin composition comprising:

• about 35 wt % to about 55 wt % of a polycarbonate resin;
• about 25 wt % to about 45 wt % of a first polycarbonate-polysiloxane copolymer resin;
• about 5 wt % to about 25 wt % of a second polycarbonate-polysiloxane copolymer resin;
• and
• about 0.1 wt % to about 2 wt % of a glycol-modified polyester resin,
• wherein the first polycarbonate-polysiloxane copolymer resin comprises a polysiloxane block having an average degree of polymerization of about 30 to about 45 and the second polycarbonate-polysiloxane copolymer resin comprises a polysiloxane block having an average degree of polymerization of about 70 to about 100,
• wherein a weight ratio of the first polycarbonate-polysiloxane copolymer resin to the second polycarbonate-polysiloxane copolymer resin ranges from about 1:0.2 to about 1:0.7,
• wherein the glycol-modified polyester resin has a 1,4-cyclohexane dimethanol (CHDM) content of about 20 mol % to 100 mol % in a diol component, and
• wherein the thermoplastic resin composition has an impact strength of about 50 cm to 90 cm, as measured on a 2 mm thick specimen using a drop impact tester in accordance with the Dupont drop test by dipping the specimen in a thinner solution for 2.5 minutes, drying the specimen at 80° C. for 20 minutes, allowing the specimen to be left at room temperature for 24 hours, and measuring a height from which dropping a 500 g dart results in breakage of the specimen.