Polymer modified water-based polyisocyanate with rigid structure and preparation method of polymer modified water-based polyisocyanate

The invention relates to a rigid structure polymer modified water-based polyisocyanate and a preparation method thereof, and belongs to the technical field of paints.The preparation method comprises the steps that aromatic polyisocyanate and a hydroxyl or amino compound containing a rigid structure react for 1-4 h at the temperature of 50-90 DEG C till the NCO content of a system reaches a theoretical value, and then the rigid structure polymer modified water-based polyisocyanate is obtained; adding a polymerization inhibitor accounting for 0.2-0.5% of the total mass of the rigid structure polymer, cooling to room temperature, and discharging to prepare the rigid structure polymer; and mixing the prepared rigid structure polymer into water-based polyisocyanate according to the mass percent of 10-50% to prepare the rigid structure polymer modified water-based polyisocyanate. By utilizing the characteristics of high reaction activity and high drying speed of the rigid structure polymer, the drying speed of the