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 from 15 to 70% by weight of a copolymer (A) of (I) from 1.5 to 15% by weight of copolymerizable compounds of 3 to 10 carbon atoms which contain a carboxyl or carboxylic anhydride group, (II) from 65 to 98.5% by weight of C1-C20-alkyl acrylates or methacrylates, (III) from 0 to 20% by weight of vinylaromatics, (IV) from 0 to 20% by weight of copolymerizable carbonyl compounds and (V) from 0 to 10% by weight of further copolymerizable organic compounds not stated under (I) to (IV), and from 30to 85% by weight of a copolymer (B) of from 60 to 100% by weight of the monomers (II) and from 0 to 40% by weight of the monomers (III) to (V), with the proviso that the copolymers (A) and (B) together contain, as components, more than 65% by weight of alkyl (meth)acrylates (II) whose homopolymers have glass transition temperatures of less than 0 DEG C., and that one or more 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 as pressure sensitive adhesives and as adhesives for laminated films.