METHOD OF PRODUCING SIMPLE POLYESTER POLYOLS Russian patent published in 2017 - IPC C08G65/30 

FIELD: chemistry.

SUBSTANCE: method for obtaining simple polyester polyols, which includes stages for obtaining the initial mixture of simple polyester polyols, including simple polyester polyols and base catalyst, is disclosed; mixing the initial mixture of simple polyester polyols with acid and water, thus neutralising said base catalyst and obtaining the first neutralised polyester polyol mixture; in the first dehydration step, at least a portion of water from said first neutralised polyester polyol, thus obtaning first dehydrated, neutralised simple polyester polyol mixture having water content of 0.00-5.00 wt % and including said simple polyester polyol and salt of said base catalyst and said acid, said salt is present as salt crystals; re-dissolution of at least a portion of salt by adding water to said first dehydrated, neutralised simple polyester polyol mixture, thus obtaining the second neutralised polyester polyol mixture; in the second dehydration step, at least a portion of water from said second neutralised simple polyester polyol mixture, thus obtaining the second dehydrated, neutralised simple polyester polyol mixture, comprising said simple polyester polyol and salt of said base catalyst and said acid, said salt is present as salt crystals; removing said salt crystals from said second dehydrated, neutralised simple polyester polyol, thus obtaining a mixture of polyether polyol.

EFFECT: improving the removal efficiency of base catalyst from simple polyester polyol.

9 cl, 3 tbl, 4 ex