Patent ID: 7588802

Claim:
A method for flame-retardant treatment of a polyester-based fiber product, comprising applying the polyester-based fiber product with a flame-retardant treating agent obtained by mixing a phosphoric acid amide represented by formula (I): wherein Ar 1 , Ar 2 , Ar 3 and Ar 4 independently denote an aryl group, with water together with at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants, and then milling the phosphoric acid amide into fine particles having a particle diameter in the range of 0.3 to 3 μm, so that the polyester-based fiber product has the phosphoric acid amide attached thereto in an amount of 0.5 to 20% by weight based on the polyester-based fiber product.