O.Z. 0050/42790 Petroleum emulsion breakers based on alkoxylated polyethyleneimines are obtained by reacting polyethyleneimine with a molecular weight of 2,500-35,000 with 5-40 moles each of propylene oxide and ethylene oxide per ethyleneimine unit in the polyethyleneimine and are used for the demulsification of petroleum emulsions at from 10.degree.C to 130.degree.C.
