| abstract |
(57) [Problem] To provide an ester-based elastomer which is flexible and has excellent long-term durability at high temperatures. SOLUTION: The structure has a crystalline aromatic polyester such as polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate or polybutylene terephthalate in a structure, and has a durometer hardness (HDD) at 23 ° C of more than 40 and not more than 50. And an ester elastomer having a compression set of 83% or less under conditions of 120 ° C. for 72 hours. |