Published: October 2007
This report continues our review of polycarbonate production technology, supplementing our earlier report PEP Report 50D issued in 1999. Polycarbonate resins are commercially produced by interfacial and transesterification or melt processes. In the interfacial process, bisphenol A (BPA) is phosgenated in an aqueous solution of sodium bisphenolate with methylene chloride as an organic solvent. In the melt process, BPA reacts with diphenyl carbonate (DPC) in a molten state without the solvent. In this report, we update the process economics and technology to produce DPC by:
- DPC from phenol by direct phosgenation
- DPC from ester exchange reaction of DMC, which is produced by the oxidative carbonylation of methanol
- DPC from ester exchange reaction of DMC, which is produced by reacting ethylene oxide with CO2 to form ethylene carbonate. Ethylene carbonate is reacted with methanol to produce DMC.
- DPC from liquid-phase decarbonylation of DPO, which is produced by reacting phenol with DMO. DMO is prepared by the carbonylation of methyl nitrite.
In this report, we also update the process economics and technology to produce polycarbonate by several processes:
- Polycarbonate by the interfacial process with on-site phosgene generation
- Polycarbonate by a conventional melt process with DPC and BPA as the starting materials
- Polycarbonate by a melt process similar to Asahi Kasei process with DPC and BPA as the starting materials