Bayer Aktiengesellschaft

Hans-Joachim Sandhagen

Pramod Gupta

Hartmut Hetzel

Martin Hoppe

Ulrich Leyrer

Werner Betz

Heinz-Jorg Rosenbaum

High functionality, low viscosity, light colored sucrose-based polyethers are prepared by reacting a starter mixture containing i) approximately 100 parts by weight of sucrose, ii) from about 30 to about 1000 parts by weight of a low molecular weight, relatively high valency alcohol and/or an alkoxylation product of such an alcohol and iii) an alkali metal hydroxide which has been prepared at a temperature of from about 20.degree. to about 110.degree. C. with an alkylene oxide at a temperature of from about 90.degree. to about 130.degree. C. and at a pressure of from about 0.3 to about 4 bar excess nitrogen pressure. These polyether polyols are particularly useful for the production of polyurethanes, particularly rigid polyurethane foams.

Process for the production of low viscosity high functionality, light

The present invention relates to a process for removing a basic catalyst from a polyether polyol having a hydroxyl number of from 4 to 250 comprising adding from 0.7 to 7 percent by weight of water, based on the polyether polyol, to an alkaline reaction medium containing the polyether polyol at a temperature of from 20.degree. to 120.degree. C.; introducing 1 to 2 times the stoichiometric amount of gaseous carbon dioxide at a temperature of from 75.degree. to 120.degree. C., thereby forming a carbonate salt; and removing the carbonate salt by filtration.

Process for the removal of catalysts for polyether polyols

This invention relates to a process for the removal of troublesome secondary products, particularly small quantities of water, solvents, low molecular weight glycols, and pungent-smelling substances, from polyethers by means of a tubular coil evaporator.

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Dormagen, Germany

Hans-Joachim Sandhagen