Abstract: A polybutadiene having a hydroxyl group at a terminal end thereof is reacted with a lactone compound such as an ?-caprolactone to obtain a polymer polyol represented by formula (I): HO—X1—Y—X2—OH (wherein X1 and X2 each independently represents a polyester component and Y represents a polybutadiene component), the polymer polyol is reacted with an unsymmetric diisocyanate to obtain a urethane prepolymer, and then the urethane prepolymer is reacted with a chain extender to obtain a polyurethane.

Abstract: A polybutadiene having a hydroxyl group at a terminal end thereof is reacted with a lactone compound such as an ?-caprolactone to obtain a polymer polyol represented by formula (I): HO—X1—Y—X2—OH (wherein X1 and X2 each independently represents a polyester component and Y represents a polybutadiene component), the polymer polyol is reacted with an unsymmetric diisocyanate to obtain a urethane prepolymer, and then the urethane prepolymer is reacted with a chain extender to obtain a polyurethane.

Abstract: A polybutadiene having a hydroxyl group at a terminal end thereof is reacted with a lactone compound such as an ?-caprolactone to obtain a polymer polyol represented by formula (I): HO—X1—Y—X2—OH (wherein X1 and X2 each independently represents a polyester component and Y represents a polybutadiene component), the polymer polyol is reacted with an unsymmetric diisocyanate to obtain a urethane prepolymer, and then the urethane prepolymer is reacted with a chain extender to obtain a polyurethane.

Abstract: A polybutadiene having a hydroxyl group at a terminal end thereof is reacted with a lactone compound such as an ?-caprolactone to obtain a polymer polyol represented by formula (I): HO—X1—Y—X2—OH (wherein X1 and X2 each independently represents a polyester component and Y represents a polybutadiene component), the polymer polyol is reacted with an unsymmetric diisocyanate to obtain a urethane prepolymer, and then the urethane prepolymer is reacted with a chain extender to obtain a polyurethane.

Abstract: An object of the present invention is to provide a method for producing a polybutadiene by anionic polymerization at a low temperature, in which the microstructures thereof is controlled to polybutadienes having diverse physical properties. The present invention provides a method for producing a polybutadiene by anionic polymerization of 1,3-butadiene in the presence of a polymerization initiator and under the conditions of a reaction temperature not higher than the boiling point of butadiene, wherein the polymerization is performed in the presence of a potassium salt in an aprotic polar solvent or in a mixed solvent of an aprotic polar solvent and a nonpolar solvent. The potassium salt is preferably potassium t-butoxide, and the solvent is preferably a mixed solvent of tetrahydrofuran and hexane. The resultant polybutadiene can be used in an adhesive composition and in a plate-making material composition used for flexographic printing plates.