Process for the preparation of mixtures of low-foam non-ionic surfactants having acetal structure

摘要

Preparation of mixtures of low-foam non-ionic surfactants having acetal structure, containing A) 70 to 99% by weight of one or more asymmetrical acetals I <IMAGE> where R<1> is a C1- to C30-alkyl radical, a C3- to C30-alkenyl radical or a C7- to C30-aralkyl radical or -alkaryl radical, R<2> is a C1- to C10-alkyl radical, A is a 1,2-alkylene group having 2 to 4 C atoms and x can assume values from 1 to 50, and B) 1 to 30% by weight of one or more symmetrical acetals II <IMAGE> where the variables R<1>, A and x have the abovementioned meanings, by reaction of alkoxylates III R<1>-(OA)x-OH (III> with vinyl ethers IV H2C=CH-O-R<2> (IV> in the presence of protic acids or Lewis acids as catalysts, by carrying out the reaction in the presence of one or more acetaldehyde dialkyl acetals V <IMAGE> where R<3> is a C1- to C10-alkyl radical and R<2> and R<3> can have the same or different meanings, in an amount from 0.1 to 20 mol of the compounds V per mole of III.