Basf Aktiengesellschaft

Peter Wittmer

Andreas Hohmann

Peter Ksoll

Wolfgang Reuther

Erwin Hahn

Rainer Dyllick-Brenzinger

Roland Ettl

Thomas Kessler

Norbert Guentherberg

Ulrich Riebeling

Enrique Freudenberg

Hans-Heinrich Bechtolsheimer

Arnold De Clercq

Solid mixtures of a reactive size and starch, which are obtainable by mixing at least one reactive size with at least one starch in a melt in the presence of at least one destructuring agent for starch under the action of shear forces at from 65 to 250&#xb0; C. and cooling the melt to room temperature, are used in the form of aqueous dispersions as process assistants in papermaking.

Mixtures of solids, consisting of a reactive sizing agent and starch, method for producing said mixtures and use thereof

A continuous process for purifying an off-gas which contains CO.sub.2 and HCl and COCl.sub.2. The process comprises passing the off-gas through a separator filled with N,N-dialkylformamide and HCl. This causes a reaction between the COCl.sub.2 and the N,N-dialkylformamide to give the Vilsmeier complex (adduct of COCl.sub.2 and dialkylformamide) and CO.sub.2. The CO.sub.2 leaving the separator contains small amounts of HCl.

Continuous purification of an off-gas composed of CO.sub.2

A process for preparing carbonyl chlorides of the formula I ##STR1## where R is C.sub.1 -C.sub.30 -alkyl, C.sub.2 -C.sub.30 -alkenyl or C.sub.2 -C.sub.30 -alkynyl, from essentially equimolar amounts of a carboxylic acid of the formula II ##STR2## where R has the abovementioned meanings, and phosgene COCl.sub.2 (III), in the presence of a catalytic adduct of phosgene and N,N-disubstituted formamide or the hydrochlorides thereof, of the formula IV where R.sup.1 and R.sup.2 are each, independently of one another, C.sub.1 -C.sub.3 -alkyl or together are a C.sub.4 -C.sub.5 -alkylene chain which may be interrupted by oxygen or by nitrogen which carries C.sub.1 -C.sub.3 -alkyl or CHO, and n is 0, 1 or 2, wherein the reaction is carried out with a stationary phase of the catalytic adduct, is described.

Preparation of carbonyl chlorides

Stabilized aqueous C.sub.14 -C.sub.22 -alkyldiketene emulsions containing, as essential components:

Stabilized aqueous alkyldiketene emulsions

Carbonyl halides of the general formula I ##STR1## where R is an organic radical of more than 7 carbon atoms and X is chlorine or bromine, are prepared by reacting carboxylic acids of the general formula II ##STR2## where R has the abovementioned meaning, with phosphorus chlorides or bromides by treating these reaction mixtures with carboxamide/hydrochloride or hydrobromide mixtures which are not homogeneously miscible with the carbonyl halides I and then separating off the carboxamide hydrochloride or hydrobromide phase.

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Neustadt, Germany

Peter Wittmer