High-temperature cross-linking dispersion

A process for preparing an aqueous dispersion, comprising:

• (1) preparing at least one blocked polyisocyanate by a process comprising:
• (A) reacting at least one polyisocyanate with at least one thermally eliminatable blocking agent selected from the group consisting of primary, monofunctional alcohols and mixtures thereof, in order to obtain at least one partly blocked polyisocyanate,
• (B) reacting the at least one partly blocked polyisocyanate from step (A) with at least one nonionic hydrophilizing agent selected from the group consisting of polyoxyalkylene ethers containing a single hydroxyl group, in order to obtain an intermediate, and
• (C) reacting the intermediate obtained in step (B) with at least one thermally eliminatable blocking agent selected from the group consisting of primary, monofunctional alcohols and mixtures thereof, in order to obtain the at least one blocked polyisocyanate, wherein the theoretical isocyanate group content of the reaction mixture after step (C) is 0% by weight;
• and
• (2) preparing the aqueous dispersion by:
• (D) dispersing the at least one blocked polyisocyanate obtained in step (C) in water to form the aqueous dispersion, the at least one blocked polyisocyanate obtained in step (C) being the only at least one blocked polyisocyanate in the aqueous dispersion.