| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a polyester fiber which is low-cost and has improved durability due to improved hydrolysis resistance of the polyester fiber while keeping physical characteristics and quality required in industrial material applications.SOLUTION: A polyester fiber contains a phosphoric acid alkali metal salt and has a strong force retention rate, in an in-rubber heat resistance test, of 85% or higher. The hydrolysis of the polyester fiber is suppressed by neutralizing a proton of a carboxyl terminal group produced newly by the hydrolysis reaction of the phosphoric acid alkali metal salt, with the proton acting as a catalyst for the hydrolysis reaction.</p> |
