Patent ID: 7812061

Claim:
A method for manufacturing a recycled polycarbonate raw material for a flame retardant resin composition from discarded and/or recovered optical discs, wherein the optical discs comprise a polycarbonate resin in a substrate material, the method comprising: (a) identifying, by measuring a monomer composition and a fraction of the terminal OH groups, whether the polycarbonate resin used in the substrate material of the discarded and/or recovered optical discs is manufactured by polymerizing a raw material comprising a divalent phenol, wherein the divalent phenol is only 2,2-bis(4-hydroxyphenyl)propane; (b) separating the discarded and/or recovered optical discs in which the polycarbonate resin in the substrate material is manufactured by polymerizing a raw material comprising a divalent phenol, wherein the divalent phenol is only 2,2-bis(4-hydroxyphenyl)propane; and (c) removing impurities from the discarded and/or recovered optical discs separated in (b) by an alkaline treatment, thereby obtaining the recycled polycarbonate raw material for a flame retardant resin composition, wherein the impurities are originated in layers other than a substrate.