| 摘要 |
PROBLEM TO BE SOLVED: To provide polyurethane for a synthetic leather that has well-balanced physical properties of flexibility, chemical resistance, low temperature characteristics, heat resistance and touch feeling.SOLUTION: The polyurethane for a synthetic leather is obtained by reacting (a) a compound containing two or more isocyanate groups in one molecule, (b) a chain extender and (c) a polycarbonate diol. For the (c) polycarbonate diol, the hydroxyl value is 20 mg-KOH/g or more and 45 mg-KOH/g or less, the glass-transition temperature measured by a differential scanning calorimeter is -30°C or less, and the average carbon number of a dihydroxy compound obtained by hydrolyzing the polycarbonate diol is 3 or more and 5.5 or less. |
