Polyester Resin Composition with Excellent Impact Resistance and Light Reliability and Molded Article Using the Same

A polyester resin composition, comprising:

• (A) two polyester resins including an aliphatic ring structure and having different trans/cis isomer ratios in the aliphatic ring, wherein the two polyester resins (A) include:
• (A-1) a first polyester resin having a trans/cis isomer ratio of 2.5 to about 3.0;
• and (A-2) a second polyester resin having a trans/cis isomer ratio of about 1.8 to less than 2.5, wherein the trans/cis isomer ratio of the first polyester resin (A-1) is not the same as the trans/cis isomer ratio of the second polyester resin (A-2);
• (B) a white pigment;
• and
• (C) an inorganic filler,
• wherein a weight ratio of the first polyester resin (A-1) to the second polyester resin (A-2) ranges from about 1:4 to about 4:1,
• wherein the inorganic filler (C) comprises (C-1) a first inorganic filler and (C-2) a second inorganic filler, and wherein the first inorganic filler (C-1) comprises glass fibers and the second inorganic filler (C-2) comprises wollastonite,
• wherein a weight ratio of the first inorganic filler (C-1) to the second inorganic filler (C-2) ranges from about 1:3 to about 3:1, and
• wherein the polyester resin composition has a crystallization temperature (Tc) of about 230° C. to about 250° C., as measured by differential scanning calorimetry (DSC) while cooling the resin composition at a cooling rate of −100° C./min.