Abstract: Preparation of polyisobutylene having a content of terminal double bonds of more than 50% by polymerizing isobutene using a polymerization catalyst customary therefor from a technical 1-butene-, 2-butene- and isobutene-containing C4 hydrocarbon stream which may comprise up to 3000 ppm by weight, of 1,3-butadiene, by reducing the content of oxygenates in the C4 hydrocarbon stream before the polymerization of the isobutene by contacting it with an inorganic adsorbent at a pressure of from 1 to 20 bar and a temperature of from 20 to 220° C.

Abstract: The present invention relates to antifreeze/anticorrosion concentrates comprising from 10 to 50% by weight, based on the total amount of the concentrate, of glycerol, to processes for preparing such concentrates from superconcentrates, to aqueous coolant compositions from these concentrates, and to their use, for example in internal combustion engines.

Abstract: The present invention relates to a process for preparing trioxime derivatives of the formula I in which the substituents R1 and R2 are identical or different and each is cyano, alkyl, haloalkyl or cycloalkyl, and R3 and R4 are identical or different and each is alkyl, haloalkyl, cycloalkyl, alkylcarbonyl or arylalkyl, by the following reaction steps in water without isolation of the intermediates: A) nitrosation of 1,3-diketones of the formula II ?to give monooximes of the formula III, B) oximation of III with hydroxylamine derivatives of the formula IV H2N—OR3???IV ?in which R3? is hydrogen or a group R3 to give bisoximes of the formula V, C) alkylation of V with alkylating agents or acylation of V with acylating agents to give compounds of the formula VI and D) subsequent oximation of VI with hydroxylamine to give compounds of the formula I.

Abstract: The present invention relates to a process for preparing for preparing [sic] trioxime derivatives of the formula I 1

Abstract: A process is described for the continuous preparation of dimethylvinylcarbinol (DMVC) by continuously reacting prenol with the aqueous solution of a protic acid in the still or in the lower part of a rectification column while distilling off the DMVC formed in the form of an azeotropic mixture with water, which comprises a) during the reaction ensuring that as far as possible no liquid two-phase mixture forms in the reaction mixture, b) distilling off the DMVC which forms at a reflux ratio of at least 2, as a result of which there is virtually no more prenol present in the distillate from the column, and c) setting the reaction volume and/or the amount of prenol added per hour and/or the concentration of protons in the reaction mixture in such a manner that the quotient, defined as residence time concentration coefficient, of the reaction volume and the volume of prenol added per hour multiplied by the concentration of protons in the reaction mixture has a value between 0.

Abstract: Allyl alcohols are isomerized in aqueous solution in the presence of protonic acids, with the pH of the reaction mixture being adjusted to the range from 2 to 5 with an acid concentration below 0.16 mol per liter of the reaction mixture or with a buffer which comprises the protonic acid.