The invention discloses a photochromic
polyester fiber with a sheath-core structure, which comprises a sheath layer and a core layer, wherein the
mass ratio of the sheath layer to the core layer is 2:8 to 4:6; the sheath layer is
polyester resin, and the core layer comprises core layer fibers and color master batch for coloring the core layer fibers, wherein the
mass percentage of the color
masterbatch to the core layer is 3% to 10%; the color master batch comprises, by weight, 0-90 parts of a carrier, 1-30 parts of photochromic
powder, 0-20 parts of a dye, 0.3-1.5 parts of a heat stabilizer,0.2-1 part of an
antioxidant, and 0.5-1.5 parts of a dispersion aid. According to the photochromic
polyester fiber with the sheath-core structure, the color master batch is added into the core layer,so that the original solution coloring of the polyester
fiber is achieved, the production cost is reduced, and the environmental
pollution is reduced; moreover, since the color master batch containsphotochromic
powder, the polyester fiber gains photochromic characteristics; and the photochromic effect is long, so that the use requirement is met.