▎ 摘　　要

NOVELTY - Preparing polyborosiloxane modified polyurethane aqueous coating comprises dissolving borate in water, adding chlorosilane dropwise, stirring, reacting, drying, adding polydimethylsiloxane, adjusting the amount of raw materials added, controlling molar ratio of boron and silicon in borosiloxane prepolymer to obtain variety of borosiloxane prepolymers with different molar ratios, where the borosiloxane prepolymers with different molar ratio comprises (a) borosiloxane prepolymer with molar ratio of boron and silicon is 1:50, (b) borosiloxane prepolymer with molar ratio of boron and silicon is 1:30, and (c) borosiloxane prepolymer with molar ratio of boron and silicon is 1:10, taking isocyanate, borosiloxane prepolymer (a), (b) and (c), and dibutyltin dilaurate, performing reaction at 40-50℃, adding polyol, heating at 80-85℃, adding diethylene glycol and dimethylol propionic acid, continuing reaction, adding triethylamine for neutralization, discharging and emulsifying. USE - The method is useful for preparing polyborosiloxane modified polyurethane aqueous coating. ADVANTAGE - The method enables to prepare polyborosiloxane modified polyurethane aqueous coating, which has excellent water resistance and water resistance.