Process for the production of polycarbonate of constant viscosity

US5412060A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Claus Wulff · Krefeld, DE
• Uwe Hucks · Alpen, DE
• Rolf Bachmann · Busswil, CH
• Gunther Weymans · Leverkusen, DE
• Jurgen Kadelka · Krefeld, DE
• Wolfgang Herrig · Bensberg, DE

Key dates

• Filing date: Jan 31, 1994
• Grant date: May 2, 1995
• Expiry date: Jan 31, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G64/24
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the production of polycarbonates by the two-phase interfacial method in which deviations between measured and estimated variables are continuously minimized by means of a suitably selected observer or filter system on the basis of a process model with an empirical Mark-Houwink relation adapted to the process. The variables estimated by the observer/filter are converted into control variables which are used to set input streams of the production process. Product quality is kept constant, changes in load or set values are quickly intercepted and even disturbances not readily accessible to measurement are taken into account by the process control.