| abstract |
PROBLEM TO BE SOLVED: To sufficiently suppress the by-production of tetrahydrofuran in a reaction of synthesizing a polycarbonate polyol by reacting 1,4-butanediol and diisocyanate, thereby increasing the production efficiency of this reaction. Uniform properties of polyurethane resin such as flexibility and coating strength for each polymerization lot. In a reaction to obtain a copolycarbonate diol by reacting 1,4-butanediol with an aliphatic glycol having 5 to 20 carbon atoms and a carbonate selected from dialkyl carbonate, diaryl carbonate, and alkylene carbonate. A copolycarbonate diol is produced by carrying out the reaction in the presence of a compound having a 3,5-di-tert-butyl-4-hydroxyphenyl skeleton. |