Patent ID: 7005495

Claim:
A polycarbonate diol comprising recurring units each independently represented by the following formula (1): wherein R represents a divalent aliphatic or alicyclic hydrocarbon group having 2 to 10 carbon atoms, and terminal hydroxyl groups, wherein 50 to 100% by mole of said recurring units of formula (1) are each independently represented by the following formula (2): wherein n is 5 or 6, and wherein: when the amount of recurring units of formula (2) wherein n=5 is from 50 to 100% by mole, based on the total molar amount of said recurring units of formula (1), said polycarbonate diol has a primary terminal OH ratio of 97% or more, and when the amount of recurring units of formula (2) wherein n=5 is from 0 to less than 50% by mole, based on the total molar amount of said recurring units of formula (1), said polycarbonate diol has a primary terminal OH ratio of 99% or more, said primary terminal OH ratio being defined as the weight percentage of diol monomers having primary hydroxyl groups at both terminals thereof, based on the total weight of the alcohols inclusive of diol monomers, wherein said alcohols, inclusive of diol monomers, are derived from the terminal diol segments of said polycarbonate diol and are contained in a fraction obtained by heating said polycarbonate diol at a temperature of from 160 to 200° C. under a pressure of 0.4 kPa or less while stirring.