Provided are a urethane resin solution to provide a urethane resin having
a low tensile elasticity, a low elastic modulus under low temperatures,
good elastic recovery, excellent heat resistance and excellent adhesion,
a production method of the solution and a production method of the
urethane resin.An isocyanate group-terminated prepolymer is synthesized
by reacting a polyisocyanate compound with a polyetherester diol having a
molecular weight of from 800 to 4,000, which is obtained by a
ring-opening polymerization of a mixture of an alkylene oxide and a
lactone monomer using a polyoxy tetramethylene diol having a molecular
weight of from 500 to 2,500 as an initiator and using a composite metal
cyanide complex catalyst if necessary, and the resulting prepolymer is
reacted with a chain extender, for example, comprised of a low molecular
weight diamine and/or a low molecular weight diol, in an organic solvent.
The urethane resin solution obtained is molded into a predetermined
shape, or a substrate is coated or impregnated with the urethane resin
solution and thereafter the organic solvent is removed to obtain a
urethane resin.