The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 13, 2001
Filed:
Aug. 13, 1999
Paul Wagner, Düssledorf, DE;
Frank Döbert, Köln, DE;
Thomas Menzel, Hilden, DE;
Torsten Groth, Odenthal, DE;
Winfried Joentgen, Köln, DE;
Ulrich Liesenfelder, Bergisch Gladbach, DE;
Jörgen Weinschenck, Krefeld, DE;
Klaus-Peter Heise, Odenthal, DE;
Bayer AG, Leverkusen, DE;
Abstract
The invention relates to a method for carrying out polycondensation reactions, according to which the polycondensation of a monomeric starting material is carried out with external supply of heat in a reactor combination which has at least two stages and is composed of a pre-reactor and a high-viscosity reactor, where the low-molecular-weight elimination products produced are removed by evaporation. In the pre-reactor, the reaction product is concentrated to give a high-viscosity preliminary product. The high-viscosity preliminary product is then fed to the high-viscosity reactor, in which it reacts to completion with simultaneous introduction of thermal and mechanical energy and with a residence time of from 20 s to 60 min to give a polycondensation product.