abstract |
A polyurethane comprises (a) organic diisocyanate units and (b) polycaprolactone polyol units having a narrow molecular weight distribution in which a ratio of the weight average molecular weight to the number average molecular weight is in the range of from 1.1 to 2.0 and the average molecular weight is 500 to 5,000, the units (a) and (b) being connected linearly through urethane linkages. |