Patent ID: 11655331

Abstract:
A method for preparing a high-temperature self-crosslinking aqueous polyurethane dispersion. By using isocyanate (NCO) blocking agent to block part of the NCO, and using the hydroxyalkyl ethylenediamine chain extender in the post-chain extension stage to introduce hydroxyl groups, the polymer macromolecular structure containing both blocked NCO groups and hydroxyl groups can be prepared. The aqueous polyurethane dispersion does not need to mix with other waterborne resins and crosslinkers when applied. A sufficient cross-linking reaction is performed between the NCO released and hydroxyl groups on the polymer macromolecular chain to form a high-density cross-linked structure when curing at 100-150° C. for 20-30 min, thus obtaining a high-performance waterborne coating that can be used in the form of one-pack.