Abstract: A flameproof rayon fiber having excellent flameproofness as well as excellent flame retardance, a method for manufacturing the same, and a flameproof fiber structure are provided. The flameproof rayon fiber according to the present invention includes components of silicon and sodium. Glass remains when the fiber is burned at 800° C., the glass component has a property of softening at 800° C., and when subjected to an X-ray fluorescence analysis, the rayon fiber has a silicon content in the range of 5 to 30% by mass and a sodium content in the range of 0.1 to 3% by mass.

Abstract: A rayon fiber that does not use a halide-based flame retardant, a phosphorous flame retardant or an organic solvent, has excellent flameproofness and launderability and is biodegradable when buried in the soil at the time of disposal, and a method for manufacturing the same are provided. The flameproof rayon fiber according to the present invention contains components of silicon and magnesium, and a compound containing the components of silicon and magnesium is amorphous.

Abstract: A rayon fiber that does not use a halide-based flame retardant, a phosphorous flame retardant or an organic solvent, has excellent flameproofness and launderability and is biodegradable when buried in the soil at the time of disposal, and a method for manufacturing the same are provided. The flameproof rayon fiber according to the present invention contains components of silicon and magnesium, and a compound containing the components of silicon and magnesium is amorphous.