The invention discloses a preparation method of noctilucent fibers capable of emitting
red light in
darkness. The preparation method comprises the following steps: mixing 2-hydroxybenzaldehyde with 3-hydroxyl-N,N-
dimethylaniline which can be dissolved in water to obtain a mixture, heating the mixture, mixing the mixture with
anhydrous zinc chloride and
sulfuric acid to obtain a mixture I, and carrying out the reaction on the mixture I to obtain a light conversion agent; mixing the light conversion agent with SrAl2O4:Eu<2+>, Dy<3+> and a
fiber forming
polymer base material to obtain a mixture II,
smelting the mixture II, and granulating to obtain noctilucent particles for
spinning; and
drying the noctilucent particles, then
smelting the noctilucent particles and
spinning to obtain the noctilucent fibers. The
red light emitted by the noctilucent fibers prepared by adopting the preparation method can be maintained for more than ten hours, the highest luminance can reach 3.0cd / m<2>, the emitted
red light is one of three basic colors, and the noctilucent fibers can be compounded with one or two of
blue light noctilucent fibers and
green light noctilucent fibers to prepare luminous colorful noctilucent fibers, so that the important significance can be realized.