Polycarbonate diol composition and coating material composition comprising same

A polycarbonate diol composition consisting of a polycarbonate diol represented by the following formula (AA) and a diol component represented by the following formula (BB), wherein

• 90% by mol or more of a total quantity of a terminal group calculated from a proportion of a total hydroxyl group to a total quantity of a terminal hydroxy group is a hydroxy group,
• a hydroxy value is 10 to 400 mg-KOH/g,
• a proportion of the polycarbonate diol is 80% by mass or more and 99.90% by mass or less and a proportion of the diol component is 0.10% by mass or more and 20% by mass or less based on 100% by mass in total of the carbonate diol and the diol component, and
• an area percentage (%) of the polycarbonate diol having a number-average molecular weight of 500 or lower in molecular weight calculation results obtained by calculation by the gel permeation chromatography (GPC) measurement of the polycarbonate diol composition is 1% or more and 20% or less, and
• a proportion of the diol component represented by the formula (BB) in a dihydroxy compound obtained by the hydrolysis of the polycarbonate diol composition is 5% by mol or more, and 65% by mol or less:
• wherein R11 is a C2-C7 divalent linear, a C3-C7 branched or a C4-C7 cyclic aliphatic hydrocarbon group optionally containing a heteroatom, or a C6 divalent aromatic hydrocarbon group optionally containing a heteroatom, and a plurality of R11 moieties are the same as or different from each other;
• and aa is a number of 1 or larger and 50 or smaller,
• HO—R22-OH (BB)
• wherein R22 is a divalent linear or branched aliphatic hydrocarbon group having 2 or more and 5 or less carbon atoms and optionally containing a heteroatom.