The invention relates to an aqueous dispersion and dispersion powder composition for highly flexible, waterproof, hydraulically binding tile adhesives having an extended open time, and containing an emulsion polymer (A) having a glass transition temperature (Tg) of approximately 10° C. to 80° C., and an emulsion polymer (B) having a glass transition temperature (Tg) of approximately −60° C. to +20° C. The difference of the glass transition temperatures (Tg) of the emulsion polymers (A and B) is at least approximately 5° C. The proportion of vinyl acetate monomer units is 0 to 70 mol-% and the minimum film forming temperature according to DIN 53787 of the 50% aqueous dispersion composition is approximately 15° C. or less, and the monomers, stabilization systems and optionally the additional additives of the dispersion and/or dispersion powder composition are selected such that a good cement compatibility is guaranteed. Due to the inventive dispersion and dispersion powder composition, tile adhesive can be produced in an economical manner which meets the requirements of C2S2- and C2ES2-norm according to EN12004.