This invention relates to the use of a water-soluble or water-dispersible copolymer comprising, in the form of polymerized units: (a) at least one monomer compound of general formula I: (b) at least one hydrophilic monomer bearing a function of acidic nature which is copolymerizable with (a) and capable of ionizing in the application medium, (c) optionally, at least one hydrophilic monomer compound containing ethylenic unsaturation and of neutral charge, bearing one or more hydrophilic groups, which is copolymerizable with (a) and (b), the a/b molar ratio being between 60/40 and 5/95, to give a hard surface hydrophilic properties.