Water-soluble polymers and use as building material auxiliaries

A water-soluble copolymer having a VT.sub.24 Haake viscosity at 25.degree. C. of 100 to 4000 mPa.s rendering it suitable for use as a flow controlling auxiliary for building material, consisting

• (1) 5 to 50 mol % of radicals of the general formula ##STR8## (2) 0 to 20 mol % of radicals of the general formula ##STR9## (3) 5 to 50 mol % of radicals of the general formula ##STR10## (4) 5 to 50 mol % of radicals of the general formula ##STR11## (5) 2 to 50 mol % of radicals of the general formula ##STR12## (6) 5 to 50 mol % of radicals of the general formula ##STR13## wherein, in the radicals of the formulae (I) to (IV), R.sub.1 denotes hydrogen or a methyl group,
• R.sub.2 denotes an alkoxycarbonyl group with 1 to 4 carbon atoms in the alkoxy group, an alkanoyloxy group with 1 to 4 carbon atoms or a .beta.-hydroxyalkoxycarbonyl group with 2 or 3 carbon atoms,
• R.sub.3 denotes methyl or an ethyl group,
• R.sub.4 denotes a hydrogen or a methyl group,
• R.sub.5 and R.sub.6 are identical or different and denote hydrogen, a methyl or ethyl group or together form a trimethylene or pentamethylene ring,
• R.sub.7 denotes hydrogen or a methyl group, and
• Y denotes a covalent bond or a group of the formula --CO--NH--C(CH.sub.3).sub.2 --CH.sub.2 -- or ##STR14## and wherein the sum of (1) to (6) must always by 100 mol %.