SAIS DE ESTERES DE ACIDOS FOSFORICOS SULFONADOS COMO ANGENTES DE ENGRAXAMENTO DE COURO

A dubbing agent for leather contains alkali, amine and/or NH4 salts of sulphonated phosphoric acid esters, obtd. by reacting phosphoric acid esters of formula I with sulphonating agents, followed by hydrolysis with alkali hydroxides, NH4OH and/or amines. R1 = 8-22C alkyl or alkenyl; R2, R3 = H or 8-22C alkyl or alkenyl; m, n, p = 2-4; x, y, z = 0-30. Pref. R1 = 12-18C alkyl or alkenyl; R2, R3 = H or 12-18C alkyl or alkenyl; m, n, p = 2; x, y, z = 0-10. Leather, tanned, post-tanned or dyed, is dubbed with the esters, the dubbing bath is brought to pH 3.5-4.1 with acid, and the ester salts are fixed on and in the leather by addn. of Cr and/or Al tanning agents. The salts, pref. alkali salts, of the esters are used, opt. with other dubbing agents, in amt. of 1-20 (2-14) wt.%, w.r.t. pared leather, and the bath is brought to pH 3.8-4.0 with formic, acetic and/or sulphuric acid.