| abstract |
PROBLEM TO BE SOLVED: To provide a sharp, excellent color tone, an extremely small amount of deposits adhered to a spinneret even when continuously spun through a spinneret for a long time, and excellent moldability. Provided are a polyester fiber having improved properties and a method for producing the same. SOLUTION: An aromatic dicarboxylic acid is produced by using a reaction product of a titanium compound and / or a titanium compound component containing a titanium compound obtained by reacting a titanium compound with a polyvalent carboxylic acid or an anhydride thereof and a phosphorus compound component as a catalyst. A polycondensation reaction of a polymerization starting material comprising an alkylene glycol ester of an acid and / or a low polymer thereof, and at any stage before the synthesis of the polyester is completed, A polyester polymer obtained by adding a metal-containing phosphorus compound and an alkaline earth metal compound to the polyester synthesis system without previously reacting the metal-containing phosphorus compound and the alkaline earth metal, and then completing the synthesis. Is melt-spun into fibers, and 2 to 40% by weight of the fibers are eluted with an aqueous solution of an alkali compound to form micropores on the fiber surface. |