PHOSPHOLIPID-BILAYERS AS VEHICLES OF AN ANTHRAQUINONE DISPERSE DYE INLEATHER DYEING

Studies are described on the use of multilamellar lipid vesicles (MLV) as carriers of disperse dyes in the dyeing of tanned leather. We inve stigated Liposomes made up of egg phosphatidylcholine containing the a nthraquinonic disperse dye Oracetblau 2R, (C.I. Disperse Violet 1) at different phospholipid/dye concentrations. The physical stability of t hese systems was assessed by measuring the mean vesicle size distribut ion of lipid vesicle suspensions after preparation and during the dyei ng process. Kinetic aspects involving dye adsorption on tanned leather by means of MLV liposomes at different dye/lipid ratios were also inv estigated. This process leads to controlled dye exhaustion on leather, directly dependent on the relationship between the dye and lipid comp onents, with a clear improvement in the dispersing efficiency of these systems as compared with the use of conventional dispersing agents fo r this dye. The optimum dye exhaustion was obtained for the dye/phosph olipid concentrations 0.53 mM and 1.0 mM respectively with an improved dye distribution on the leather surface. These relative compositions corresponded to the weight ratios of both components at which these sy stems reached the maximum encapsulation efficiency.