BASF Aktiengesellschaft Stabilized aqueous alkyldiketene emulsions of the disclosure: Stabilized aqueous Cl4-C22-alkyldiketene emulsions containing, as essential components: (a) from 10 to 60 % w/w of at least one C14-C22-alkyldiketene, (b) from 1 to 10 % w/w of at least one protective colloid and (c) from 0.1 to 20 % w/w of at least one ester of formula I (I) in which R1 and R2 each denote Cl4-C22-alkyl, R1 differing in this case from R2 by at least 4 carbon atoms in the alkyl chain, and/or the same or different C14-C22-alkenyl groups, or at least one ester of the formula R3-O-CO-O-R4 (II),in which R3 and R4 are alkyl or alkenyl radicals of from 2 to 22 carbon atoms or at least one urethane of formula III (III), in which R5, R5 and R7 are the same or different alkyl or alkenyl radicals of from 2 to 22 carbon atoms and one of the substituents R5, R6 and R7 contains at least 12 carbon atoms, and showing a ratio of emulsified components (a):(c) from 200:1 to 1:1 and the use of compounds of formulae I to III as stabilizers for the preparation of alkyldiketene emulsions containing at least 10% w/w and preferably from 16 to 40% w/w of emulsified alkyldiketene.