Water-soluble polymers carrying quaternary ammonium groups, their preparation and use

A water-soluble polymer having quaternary ammonium groups, prepared by reacting

• (a) a low molecular weight alkylating agent with
• (b) a corresponding polymer carrying tertiary, quaternizable amino groups,
• wherein
• (a) is a low molecular weight oxirane of the formula ##STR4## wherein R.sup.6 and R.sup.7 each independently is hydrogen or alkyl of 1 or 2 carbon atoms optionally substituted by hydroxy or chloride or R.sup.6 or R.sup.7 together represent a 1,3-propylene or 1,4-butylene chain forming a five- or six-membered ring with the carbon atoms of the oxirane;
• (b) is a polymer which is prepared by epoxidizing up to a content of titratable epoxy oxygen of 2-10 weight %, a polymer of 1,3 butadiene monomer having a molecular weight (M.sub.n) of 500-6,000, and prepared from at least 70 mole % of 1,3-butadiene and up to 30 mole % of another copolymerizable 1,3-diolefin or an .alpha.-unsaturated monoolefin,
• aminating the resultant epoxidation product with a primary-tertiary or secondary-tertiary diamine of the formula ##STR5## wherein, R.sup.1 is hydrogen and
• n is an integer of 2 to 6,
• R.sup.2 and R.sup.3 each independently is hydrogen of alkyl of 1-4 carbon atoms, ##STR6## represents the same or different chain members, and R.sup.4 and R.sup.5 each independently is straight chain alkyl of 1-4 carbon atoms optionally substituted by hydroxy or alkoxy of 1-4 carbon atoms, excluding the .alpha.-position of the alkyl residue as a point of substitution, or R.sup.4 and R.sup.5 together can form a five- or six-membered ring together with the tertiary nitrogen atom;
• or
• R.sup.1 is alkyl of 1 or 2 carbon atoms, optionally substituted by hydroxy or alkoxy of 1 or 2 carbon atoms, excluding the .alpha.-position of the alkyl residue,
• n and R.sup.2 through R.sup.5 are as defined above, and
• when n is 2 and R.sup.2 and R.sup.3 each is hydrogen, then R.sup.1 and R.sup.4 together with the two nitrogen atoms can also form a six-membered ring,
• up to a content of tertiary, quaternizable amino groups of 0.05-0.5 mole/100 g of the amination product, said groups being located in the side chain and linked to a carbon atom stemming either from the primary chain or from a vinyl group of the polymer via 3-7 chain atoms, and
• in the quaternization reaction, 0.05-0.5 mole of the tertiary amino groups/100 g of the amination product are quaternized.