Polymer ammonium salts

A polymer ammonium salt which is formed from a copolymer (A) and from one or more amines (B), the copolymer (A) being obtained by copolymerizing a monomer mixture:

• (a.sub.1) ethylene,
• (a.sub.2) acrylic acid and/or methacrylic acid and
• (a.sub.3) one or more further monomers from the group consisting of vinyl esters, vinyl ethers, acrylates, methacrylates, acrylamides and methacrylamides, for whose weight ratios the following conditions apply:
• parts by weight of (a.sub.1)+(a.sub.2)+(a.sub.3)=100,
• 30 parts by weight.ltoreq.parts by weight of (a.sub.1).ltoreq.70 parts by weight,
• 5 parts by weight.ltoreq.parts by weight of (a.sub.2).ltoreq.50 parts by weight, and
• 5parts by weight.ltoreq.parts by weight of (a.sub.3).ltoreq.40 parts by weight,
• wherein the amines (B) are selected from the group consisting of:
• (b.sub.1) cyclic amines of the formula I ##STR10## where R.sup.1 is hydrogen, C.sub.1 -C.sub.6 -alkyl, -hydroxy-C.sub.1 -C.sub.6 -alkyl or (.omega.-hydroxypolyalkylene oxide)-.alpha.-yl, Z is oxygen, sulfur, NH or C.sub.1 -C.sub.5 -alkylidene and n and m are each an integer from 1 to 4,
• (b.sub.2) open-chain amines of the formula II ##STR11## where R.sup.2 is C.sub.1 -C.sub.5 -alkyl, phenyl, hydroxyl, .omega.-amino-or .omega.-thiolo-C.sub.2 -C.sub.10 -alkyl or a (.omega.-hydroxypolyalkylene oxide), (.omega.-aminopolyalkyleneimine) or (.omega.-thiolopolyalkylene sulfide)-.alpha.-yl, R.sup.3 is hydrogen or C.sub.1 -c.sub.5 -alkyl and p is from 1 to 10, and
• (b.sub.3) 1,4-thiazine, N, N',N"-trisvinylmelamine and N,N',N"-trisallylmelamine, or mixtures thereof.