Copolycarbonate and composition containing the same

A polycarbonate composition comprising:

• a polycarbonate;
• and
• a copolycarbonate,
• wherein the copolycarbonate comprises:
• an aromatic polycarbonate-based first repeating unit;
• and aromatic polycarbonate-based second repeating units having siloxane bonds,
• wherein the copolycarbonate has a melt index (MI) of 3 to 9 g/10 min as measured accordance with ASTM D1238 (300° C., 1.2 kg conditions), and a transparency of 87 to 91% as measured in accordance with ASTM D1003 (layer thickness of 3 mm), and
• wherein the second repeating units comprise a repeating unit represented by Chemical Formula 2 and a repeating unit represented by Chemical Formula 3:
• in Chemical Formula 2,
• each of X1 is independently C1-10 alkylene,
• each of R5 is independently hydrogen;
• C1-15 alkyl unsubstituted or substituted with oxiranyl, oxiranyl-substituted C1-10 alkoxy, or C6-20 aryl;
• halogen;
• C1-10 alkoxy;
• allyl;
• C1-10haloalkyl;
• or C6-20 aryl, and
• n is an integer of 10 to 50,
• in Chemical Formula 3,
• each of X2 is independently C1-10 alkylene,
• each of Y1 is independently hydrogen, C1-6 alkyl, halogen, hydroxy, C1-6 alkoxy, or C6-20 aryl,
• each of R6 is independently hydrogen;
• or C1-15 alkyl unsubstituted or substituted with oxiranyl, oxiranyl-substituted C1-10 alkoxy, or C6-20 aryl;
• halogen;
• C1-10 alkoxy;
• allyl;
• C1-10haloalkyl;
• or C6-20 aryl, and
• m is an integer of 55 to 80.