| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a polycarbonate diol with good transparency of which color tone does not deteriorate even when heated and of which both molecular weight and composition exhibit small changes.SOLUTION: A polycarbonate diol having a number average molecular weight of 250 or more and 5500 or less, and at least comprising structural unit derived from dihydroxy compound having moiety represented by the following general formula (1) in part of the structure, characterized to further contain orthophosphoric acid and/or phosphorous acid, and the total content of orthophosphoric acid and phosphorous acid in terms of phosphorous atom, relative to the total content of the metal element derived from transesterification catalyst is at 0.1 mole-fold or more and 50 mole-fold or less.</p> |
