Polycarbonate-based resin composition

A polycarbonate-based resin composition, comprising a polycarbonate-based resin (S) comprising a polycarbonate-polyorganosiloxane copolymer (S-1), which comprises a polycarbonate block (A-1) comprising a repeating unit represented by the following general formula (I) and a polyorganosiloxane block (A-2) comprising a repeating unit represented by the following general formula (II), and an aromatic polycarbonate-based resin (S-2) except the polycarbonate-polyorganosiloxane copolymer (S-1),

• wherein the polycarbonate-based resin (S) has a viscosity-average molecular weight MvPC of from 20,000 or more to 30,000 or less,
• wherein a content of the polyorganosiloxane block (A-2) in the polycarbonate-polyorganosiloxane copolymer (S-1) is from 0.5 mass % or more to 9 mass % or less,
• wherein the polyorganosiloxane block (A-2) has an average chain length “n” of from 20 or more to less than 60, and
• wherein a difference MvSi-MvPC between the viscosity-average molecular weight MvPC of the polycarbonate-based resin (S) and a viscosity-average molecular weight MvSi of the polycarbonate-polyorganosiloxane copolymer (S-1) is from −3,100 or more to 6,000 or less:
• wherein R1 and R2 each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, X represents a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, a fluorenediyl group, an arylalkylene group having 7 to 15 carbon atoms, an arylalkylidene group having 7 to 15 carbon atoms, —S—, —SO—, —SO2—, —O—, or —CO—, R3 and R4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and “a” and “b” each independently represent an integer of from 0 to 4.