Aqueous polymer dispersions having a long shelf life

摘要

Aqueous polymer dispersions which have a long shelf life are obtainable by dispersing a mixture of 15-50% by weight of a copolymer (A) of (I) 1.5-15% by weight of copolymerizable compounds of 3 to 10 carbon atoms which contain a carboxyl or carboxylic anhydride group, (II) 30-98.5% by weight of C1-C20-alkyl acrylates or methacrylates, (III) 0-60% by weight of vinylaromatics, (IV) 0-20% by weight of copolymerizable carbonyl compounds and (V) 0-20% by weight of further copolymerizable organic compounds not stated under (I) to (IV) and 50-85% by weight of a copolymer (B) of 40-100% by weight of the monomers (II) and 0-60% by weight of the monomers (III) to (V), with the proviso that the copolymers (A) and (B) together contain, as components, up to 65% by weight of alkyl (meth)acrylates (II) whose homopolymers have glass transition temperatures of less than 0 DEG C., and that one or both of the copolymers (A) and (B) contain the monomers (IV) as components, in water with the addition of ammonia and a polyhydrazide (C), and the said dispersions are used for the preparation of finishes and coatings.