The present Application relates to a polymer dispersion comprising an aqueous continuous phase and dispersed particles, which consist of a polymerized, water-soluble, urethane-modified allyl ether polyester and polymerized monomers, wherein at least two polymerized monomers A and B together with a water-soluble urethane-modified allyl ether polyester constitute the dispersion particle and are produced according to the core-shell model (multiphase).