| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyurethane excellent in flexibility and durability such as light resistance and hydrolysis resistance, which contains at least one member selected from the group consisting of a carbonate structure, an ether structure, and an ester structure in the molecular chain. SOLUTION: A polycarbonate of a molecular weight of 500-3,000 is prepared from 2,4-diethyl-1,5-pentanediol and is used as a starting material for a polyurethane containing a carbonate structure represented by formula I in the molecular chain. Further, the structure derived from a polymer diol may contain at least one member selected from the group consisting of an ether structure represented by formula II, an ester structure represented by any one of formulae III, IV, and V, and a carbonate structure represented by formula VI or VII. The polyurethane is desirably one containing a diisocyanate component being 4,4- diphenylmethane diisocyanate and a chain extender being a 2-8C aliphatic diol. |
