| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of flame retardant polyester having excellent flame retardancy, suppressing production of a byproduct and small in melting point depression of a polymer.SOLUTION: There is provided a manufacturing method of flame retardant polyester from dicarboxylic acid or an ester forming derivative thereof and diol or an ester forming derivative thereof as main raw materials including initiating a polycondensation reaction within 80 minutes after adding a phosphorus compound represented by the formula (1) to ethylene glycol with weight ratio of 10:90 to 50:50 with slurry shape to obtain polyester to which phosphorus of 0.30 to 1.10 wt.% in terms of element is polymerized. In the formula (1), R1 is an alkyl group having 1 to 18 carbon atoms, an aryl group or a hydroxyl group.SELECTED DRAWING: None |
