Method for preparing aromatic bischloroformate compositions and polycarbonates

• Main Authors: SILVA, JAMES MARIO, PYLES, ROBERT ALLEN
• Format: Patent
• Language: English; French; German
• Published: 06.10.1999
• Edition: 6
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL METHODS OF ORGANIC CHEMISTRY; 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; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PHYSICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; THEIR RELEVANT APPARATUS; TRANSPORTING

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...