| abstract |
PCT No. PCT/EP88/01177 Sec. 371 Date Sep. 21, 1989 Sec. 102(e) Date Sep. 21, 1989 PCT Filed Dec. 19, 1988 PCT Pub. No. WO89/06531 PCT Pub. Date Jul. 27, 1989.A mixture for the oxidative dyeing of human or animal hair, which is prepared immediately before application by mixing an oxidant and a dye base in cream, gel or powder form containing at least one oxidative dye and adjusting to a pH in the range of 8.0 to 10.5. The means contains in the freshly-prepared state a microencapsulated, acid-reacting compound in an amount which shifts the pH of the dye into the weakly alkaline (pH</=8), neutral or acid range. The encapsulating material for the acid-reacting compound is soluble in the alkaline dye or changeable at least in its strength properties in the sense of a weakening, the wall thickness of the microcapsules being so adjusted that the walls are dissolved or weakened within a period between 10 and 60 minutes to such an extent that the acid-reacting compound is able by itself or upon the exertion of an additional mechanical stress to emerge into the dye. Furthermore, the invention relates to the use of the means for the redyeing of dyed hair. |