Polycarbonate resin composition

A polycarbonate resin composition, comprising:

• (A) a polycarbonate resin (A) comprising a polycarbonate-polyorganosiloxane copolymer (A-1) having a polycarbonate block comprising a repeating unit represented by the general formula (I) and a polyorganosiloxane block comprising a repeating unit represented by the general formula (II):
• (B) a copolymer (B) having constituent units derived from acrylonitrile and styrene, and being free of a constituent unit derived from methyl methacrylate;
• (C) a copolymer (C) having constituent units derived from butadiene and methyl methacrylate;
• and
• (D) a flame retardant (D),
• wherein:
• a content of the polyorganosiloxane block comprising the repeating unit represented by the general formula (II) ranges from 0.70 mass % to 10 mass %, based on a total mass of the polycarbonate resin composition;
• the polycarbonate resin composition satisfies the expression (a):
• (Sf−37)×Ch/(Bd+Si)≥37 (a)
• Sf represents a flow length (cm) when the resin composition is molded with a spiral flow mold having a cylinder temperature of 240° C., a mold temperature of 40° C., and a thickness of 2.0 mm at a pressure setting of 125 MPa;
• Ch represents a Charpy impact strength (kJ/m2) at a temperature of 23° C. when the resin composition is molded into a molded body having a thickness of 4 mm;
• Bd represents a content (mass %) of the constituent unit derived from butadiene in the resin composition;
• Si represents a content (mass %) of the polyorganosiloxane block moiety in the resin composition;
• 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;
• a and b each independently represent an integer of from 0 to 4;
• and
• n represents an average number of repetitions.