| abstract |
(57) [Summary] [Problem] To make cellulose-based fibers flame-retardant without using a halogen-based flame retardant and without reducing fiber strength. SOLUTION: A polysaccharide-based fiber such as cellulose in which a compound having a phosphoryl group such as condensed phosphoric acid is uniformly contained in the fiber is treated with an aqueous solution of an aluminum compound, and if necessary, an aqueous solution of silicic acid, boric acid or the like is further added. To process. As a result, a flame-retarded polysaccharide-based fiber containing a phosphoryl group-containing compound uniformly in the fiber and having a hydrated compound layer containing aluminum as an essential component on the fiber surface is obtained. |