| abstract |
(57) [Summary] [Purpose] To provide a polyester fiber which is excellent in process stability during spinning, twisting, weaving, and the like, and is also excellent in yellowing resistance and resin adhesion. [Structure] 50 to 90% by weight of a smoothing agent component made of polyalkylene glycol and 5 to 5 containing a nitrogen atom. A treating agent containing 50% by weight is applied to the polyester fiber. [Effect] By performing heat setting before the resin adhesion treatment, the smoothing agent component made of polyalkylene glycol can be easily decomposed and removed, so that good resin adhesion can be achieved without causing yellowing. |