Patent ID: 8540885

Claim:
A method of splitting oil-water emulsions, comprising adding polyalkanolamines to an oil-water emulsion, wherein polyalkanolamines are alkoxylated polyalkanolamines (III) which are obtained by the following process: (A) condensing at least one trialkanolamine of the general formula N(R 1 —OH) 3 (Ia) and/or at least one dialkanolamine of the general formula R 2 —N(R 1 —OH) 2 (Ib) to give a polyalkanolamine (II), where the R 1 radicals are each independently a divalent, linear or branched aliphatic hydrocarbon radical having from 2 to 6 carbon atoms, the R 2 radicals are each hydrogen and/or linear or branched aliphatic, cycloaliphatic and/or aromatic hydrocarbon radicals having from 1 to 30 carbon atoms, and the resulting polyalkanolamines (II) have a mean molar mass of from 1000 g/mol to 20 000 g/mol, (B) alkoxylating the resulting polyalkanolamine (II) with ethylene oxide and propylene oxide to form alkoxylated polyalkanolamines (III) which contains polyoxyalkylene groups, where the polyoxyalkylene groups formed have block structure of the general formula —(CH 2 CH 2 O) x (CH 2 CH(CH 3 )O) y H, and where x and y are each from 3 to 100, and the y/x ratio is >1.