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AssigneeBayer Aktiengesellschaft
InventorsPaul Wagner, Frank Döbert, Thomas Menzel, Torsten Groth, Winfried Joentgen, Ulrich Liesenfelder, Jörgen Weinschenck, Klaus-Peter Heise
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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.
Method for performing polycondensation reactions to form a polycondensation product, wherein, in a first reaction step, a monomeric starting material is produced by an exothermic reaction and the temperature of the monomeric starting material is controlled via cooling before said monomeric starting material is used in a second reaction step in which the polycondensation of the monomeric starting material is performed 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 low-molecular-weight elimination products produced are removed by evaporation, further wherein reaction product becomes concentrated in the pre-reactor to give a high-viscosity preliminary product and the preliminary product reacts to completion in the high-viscosity reactor with supply of thermal and mechanical energy and with a residence time of from 20 s to 60 min in the high-viscosity reactor to give the polycondensation product.
Method for performing polycondensation reactions to form a polycondensation product, wherein, in a first reaction step, a monomeric starting material is produced by an exothermic reaction and the temperature of the monomeric starting material is controlled via cooling before said monomeric starting material is used in a second reaction step in which the polycondensation of the monomeric starting material is performed 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, further wherein reaction product becomes concentrated in the pre-reactor to give a high-viscosity preliminary product and the preliminary product reacts to completion in the high-viscosity reactor with supply of thermal and mechanical energy and with a residence time of from 20 s to 60 min in the high-viscosity reactor to give the polycondensation product which is discharged from the high-viscosity reactor along with low-molecular-weight elimination products produced in the pre-reactor and the high-viscosity reactor.
Dependencies are inferred from the claim text.