POLYURETHANE PREPOLYMER FOR PRODUCING ELASTOMER WITH IMPROVED KINETIC PROPERTIES

摘要

PROBLEM TO BE SOLVED: To obtain a polyurethane prepolymer for producing a low-cost polyurethane elastomer which can be used for tires, wheels, rollers, belts, etc., required to have good kinetic properties. SOLUTION: This prepolymer is isocyanate-terminated and is prepd. by reacting a polyisocyanate with a polyol compsn. which essentially comprises a polyether polyol prepd. from ethylene oxide, propylene oxide, or their blend and having a hydroxyl-functionality of at least 1.9 and an equivalent wt. of 350-2,000 and a low-molecular polyol having a mol.wt. of 62 or higher but lower than 300 in an equivalent ratio of the low-molecular polyol to the polyether polyol of 0.25-2.7. The prepolymer is reacted with an arom. amine chain extender to give a polyurethane elastomer.