| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an aqueous polyurethane dispersion with improved dispersion efficiency, and a system for the method. SOLUTION: The polyurethane production method comprises the first step to mix and stir a urethane prepolymer with water to obtain the first aqueous polyurethane dispersion and the second step to mix and stir the first aqueous polyurethane dispersion and at least a urethane prepolymer to obtain the second aqueous polyurethane dispersion having a polyurethane concentration higher than that of the first aqueous polyurethane dispersion. As an alternative, the production method uses a continuous dispersing apparatus, circulates a part of the aqueous polyurethane dispersion continuously extracted from the continuous dispersing apparatus and continuously supplies the dispersion together with the urethane prepolymer and water to the continuous dispersing apparatus. The system 10 for the production of the aqueous polyurethane dispersion is provided with the continuous dispersing apparatus 12 and a tank 14 and has a dispersed liquid circulation line 24. COPYRIGHT: (C)2010,JPO&INPIT |
