Process for enhancing the inherent viscosity of bisphenol polyesters
Abstract
Abstract A BISPHENOL POLYESTER WITH AN INHERENT VISCOSITY OF AT LEAST ABOUT 0.5 IS PRODUCED BY THE STEPS OF (1) PREPARING A BISPHENOL POLYESTER WITH AN INHERENT VISCOSITY OF AT LEAST ABOUT 0.1, (2) COMMINUTING THE PREPARED POLYESTER, (3) CONTACTING THE COMMINUTED POLYESTER WITH A CRYSTALLING AGENT, AND (4) HEATING THE CRYSTALLIZED POLYESTER IN THE PRESENCE OF AN INERT GAS OR UNDER REDUCED PRESSURE TO INCREASE THE INHERENT VISCOSITY TO AT LEAST 0.5. PREFERABLY A COPOLYESTER OF BISPHENOL A, TEREPHTHALIC AND ISOPHTHALIC ACID IS USED AND THE HEATING STEP IS ACCOMPLISHED BY FLUIDIZING OR POLYMERIZING UNDER REDUCED PRESSURE THE CRYSTALLIZED POLYMER IN THE SAME VESSEL AS USED FOR CRYSTALLZATION.
Inventors
- 👤 W Jackson
- 👤 H Kuhfuss
- 👤 J Caldwell
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
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