Abstract: The disclosure relates to a new and improved method of enhancing the fastness of the flame resistance properties imparted to wool by depositing a halophthalic acid derivative on the wool from an aqueous medium and which involves aftertreating such derivative-treated wool product with a fastening agent adapted to fix said derivative on the wool and thereby increase the fastness of the flame resistance properties to wet treatments and dry cleaning.

Abstract: The disclosure is concerned with a composition of matter comprising an aqueous paste of a substantially monobasic tetrachloro or tetrabromphthalate salt in finely divided form as the dispersed phase and sufficient quantities of a dispersing agent and a thickener to prevent agglomeration and settling of the dispersed phase. Preferably the monobasic salt is one that is derived from a halophthalic acid or from a halophthalic anhydride by reaction with an alkaline base wherein the quantity of base used is from 0.7 to 1.2 equivalents of the base per mole of halophthalic acid or halophthalic anhydride. The quantity of the monobasic phthalic salt can comprise from 5 to 65% of the weight of the paste. The paste is useful for imparting enhanced flame resistance to wool.