Published September 1975
The consumption of polycarbonate resins have continued to grow rapidly since our earlier report on the subject, Process Economics Programs (PEP) Report 50 (published in 1969). The promise for future growth of the industry is shown by the addition of two new companies to the previous list of six producers, and other companies are probably considering entering the field. Technological improvements, including a proliferation of specialty grades, have allowed polycarbonates to compete in an increased number of applications. All these factors suggest that this supplementary report is timely.
Polycarbonates (PC resins) are outstanding among resins in dimensional stability, impact resistance, and transparency. The flame resistance is good and is improved by modifications to make special grades. Although other resins and metals are superior in individual properties, often a combination of requirements makes a polycarbonate the only practical choice. On the negative side, the lack of resistance to many solvents is a serious shortcoming in some applications. Generally polycarbonates compete in all the fields of engineering plastics; the most rapidly growing categories have been glazing, lighting, and signs.
This report covers the technology, costs, and markets of polycarbonates, which are made by three processes: solution phosgenation, interfacial phosgenation, and transesterification. Two versions of each of the first two methods and one version of the third are considered. Also covered are the production of a flame-resistant grade and the reextrusion of resin to make special grades.
This study is limited to thermoplastic aromatic polycarbonates based on bisphenol A (BPA), which are the commercially important ones. In PEP Report 50, copolymers were considered only with respect to bisphenol A and halogenated bisphenol A or minor amounts of trifunctional branching agents. Because of commercial offerings of specialty grades, it is now important to consider both copolymers and blends; however, coverage of these is minimized. Copolymers that do not appear to be comercially significant and blends in which the polycarbonate is a minor component are excluded.
This report avoids any extensive analysis of foamed resins, fiber- reinforced resins, and flame-retardant additives, which are subjects of other PEP reports. The principal raw materials, bisphenol A, Phosgene, and tetrabromobisphenol A (TBBPA) are the subject of PEP Report No. 81.
Other PEP Related Reports: