Method for preparing aromatic bischloroformate compositions and polycarbonates

• Main Authors: SILVA; JAMES M, PYLES; ROBERT A
• Format: Patent
• Language: English
• Published: 03.12.1996
• Edition: 6
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; COMPOSITIONS BASED THEREON; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC CHEMISTRY; ORGANIC MACROMOLECULAR COMPOUNDS; PHYSICS; THEIR PREPARATION OR CHEMICAL WORKING-UP

Bischloroformate oligomer compositions are prepared by passing phosgene into a heterogeneous aqueous-organic mixture containing at least one dihydroxyaromatic compound, with simultaneous introduction of a base at a rate to maintain a specific pH range and to produce a specific volume ratio of aqueou...