| abstract |
The invention relates to a preparation method of cationic waterborne polyurethane, a genuine leather bottom sealing resin and a genuine leather coating, belonging to the field of preparation of high polymer materials. According to the invention, quaternization neutralization reaction and acid neutralization reaction are combined, and meanwhile, Michael addition reaction is further assisted for chain extension, so that the reaction degree of a cationic hydrophilic chain extender in the synthesis process is improved, and the cationic waterborne polyurethane of a soft aliphatic system is prepared, wherein the yellowing resistance grade of the cationic waterborne polyurethane is not less than 3, the modulus is lower and is 0.5-1 MPa, the breaking strength is 5-10 MPa, and the elongation is 1000-1500%; the cationic waterborne polyurethane is added with other synergists to prepare bottom sealing resin, the bottom sealing resin is sprayed on the leather and subjected to gradient heating and drying to endow the leather bottom sealing layer with better flexing resistance and flexibility, and the surface lines of the leather after beating are clear and fine and can be used as middle-high grade leather bottom sealing layer resin. |