Hair colouration, method and kit thereof
Method for colouring hair wherein a first composition comprising at least one cationic polymer and a second composition comprising at least one anionic polymer are alternately applied to the hair.
1. A method for treating hair comprising:
a) carrying out the following sequence of steps:
i) applying a first composition comprising cationic polymer to a first portion of the hair wherein the cationic polymer is branched polyethylene imine and present from 0.1 g/L to 100 g/L; and
ii) applying a second composition comprising anionic polymer to a second portion of the hair wherein the anionic polymer is polystyrene sulfonate sodium salt and present from 0.1 g/L to 100 g/L;
the first and the second portions of the hair having at least one common area wherein the method further comprises:
b) repeating step a) at least once, wherein the common area of each of the repeated steps a) has at least one common area with: the common area of step a); and
the common area of each of the other repeated steps a) in case step a) is repeated more than
once and wherein step i) or ii) further comprises the subsequent sub-steps of
removing the excess of respectively the first composition or the second composition from the hair or applying energy to the hair in the form of heat, ultrasounds, infrared or microwaves or washing or rinsing the hair.
2. The method according to claim 1 , second composition has a pH ranging from 2 to 14.
3. The method according to claim 1 , wherein the first or the second composition comprises a cosmetically acceptable salt at a concentration ranging from 0.05 to 1.5 mol/L.
4. The method according to claim 1 , wherein prior to step a), the hair is pretreated to modify the number of positive or negative charges in some portions of the hair or all over the hair.