Förfarande för att göra ett polyester/bomullstyg som innehåller åtminstone 40 vikt-% polyester eldfast, och genom förfarandet frammställt eldfast tyg

摘要

A process for imparting flame resistance to a polyester/cotton blend fabric containing at least 20% by weight polyester comprises the successive steps of: (1) applying to a polyester/cotton blend fabric a flame-retarding amount of a cyclic phosphonate ester represented by the formula: in which x is 0 or 1 or a flame-retarding amount of hexabromocyclododecane, that fixes onto the polyester fibres; (2) optionally applying to the fabric a flame-retarding amount of a prepolymer condensate of urea and a tetrakis(hydroxymethyl)phosphonium (THP) salt flame retardant that fixes to the cotton fibres, exposing the prepolymer condensate-containing fabric to a source of ammonia to form an ammoniated prepolymer to form a flame-retardant polymer network within the cotton fibre structure; and (3) applying a flame-retarding amount of THP salt and urea to the fabric, heating the fabric to form an insoluble phosphorus-containing polymer in and on the cotton fibres and oxidizing the fabric to further improve the flame resistance imparted by the phosphorus.