THERMOPLASTIC POLYURETHANE DERIVED FROM POLYTETRAMETHYLENE CARBONATE DIOL

摘要

A thermoplastic polyurethane having a number-average molecular weight of 30,000 to 200,000 and a gel content of 5 wt.% or less and basically composed of a polytetramethylene carbonate diol component with a number-average molecular weight of 500 to 10,000 and an aliphatic diisocyanate component. It is prepared by the chain extension of a prepolymer (A) represented by general formula (A) with a chain extender having an active hydrogen atom selected from the group consisting of diols with a molecular weight of 300 or less, diamines with a molecular weight of 300 or less, hydrazine and water. In formula (A), X represents (a) (wherein the average of m-number is 3 to 43; Y represents the residue of an aliphatic diisocyanate; and the average of n-number is 1 to 50. The polyurethane is excellent in the resistances to light, hydrolysis, oleic acid and alcohol. Hence it can be advantageously used in such applications as coating composition, and laminated synthetic leather or impregnated composite artificial leather made by treating a base material with this composition.