| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a method for reusing a polyester chip, capable of providing a modified polyester resin applicable as a binder for a coating material, etc., by reusing a recovered polyester. SOLUTION: This method for reusing a polyester chip comprises (1) a step of reacting 10-90 pts.wt. of a fatty acid with 90-10 pts.wt. of a polyol, (2) a second step of reacting 20-95 pts.wt. of the reaction product of the first step with 80-5 pts.wt. of a polyester chip consisting essentially of terephthalic acid and (3) a third step of reacting 40-95 pts.wt. of the reaction product of the second step with 60-5 pts.wt. of a polybasic acid. The obtained modified polyester resin produced by these steps has 1,000-3,000 number average molecular weight, 3-100 acid value and 30-200 hydroxyl number.</p> |
