| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous dispersion of a polyurethane having a higher molecular weight and exhibiting higher tensile strength compared to the one prepared by a conventional method. SOLUTION: The method for producing the aqueous dispersion of the polyurethane comprises preparing a polyurethane prepolymer solution by reacting a diisocyanate, a polycarbonate diol, a carboxylic acid diol, and a tertiary amine in a volatile polar solvent in the presence of a catalyst, mixing the polyurethane prepolymer solution with 0.1-3 mass% water as the total amount based on the total amount of the water used in the aqueous dispersion of the polyurethane and added by dividing the total to three to ten times, dispersing the resultant mixture in a sufficient amount of water, extending the chains by using a diamine, and removing the volatile polar solvent. COPYRIGHT: (C)2005,JPO&NCIPI
|
