| abstract |
Diphenylcarbonate is produced by contacting phenol with phosgene or phenylchloroformate or mixture thereof in the presence of one or more heterogeneous catalysts. The catalysts include Group VB metal oxides: silicates of Groups IIA, IIIB, IVB, VB, and the lanthanide and actinide metals: tungsten oxides: and clays. The more preferred catalysts are silicates of yttrium, titanium, or zirconium. |