The invention relates to the use of a two-phase polymer combination which is dissoluble in aqueous alkali and comprises a. an alkali-soluble copolymer or terpolymer of an α,β-unsaturated monocarboxylic acid which possesses carboxyl groups distributed essentially uniformly over the chain of the molecule, as a continuous phase, and b. a copolymer or terpolymer which is insoluble in aqueous alkali and contains epoxy groups along its polymer chain, as a discontinuous finely disperse phase, c. free epoxy groups on the surface of the polymer particles of the discontinuous phase being linked to one another by esterification with some of the carboxyl groups of the polymer of the continuous phase, and the remaining carboxyl groups being present in unchanged form, as an adhesive. The polymer combination, which is not tacky in the dry state, can be made tacky by supplying aqueous moisture to it.