Hair treatment method and kit thereof

1. A method for treating hair comprising:

A) applying a composition A comprising at least one pigment to a first portion of the hair having a first initial colour to impart the first portion of the hair with a second colour different to the first initial colour,

wherein the at least one pigment has a D 50 particle diameter of 20 nm to 1 μm, and wherein the difference between the L* value of the second colour and the L* value of the first initial colour L* second colour −L* initial first colour is ≥1, according to the International Commission on Illumination color space (“CIE L* a* b*”) system; and

B) prior to step A), providing in at least a second portion of the hair one or more polymeric sublayers, wherein the first and second portions of the hair have at least one first common area, wherein step B) comprises:

B1) applying a composition B1 comprising one or more cationic polymers to the second portion of the hair.

2. The method according to claim 1 , wherein the second colour has a L* value L*second colour of ≥22, according to the CIE L* a* h* system.

3. The method according to claim 1 , wherein the overall colour change, represented by ΔE where ΔE=[(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 ] 1/2 , from the first initial colour to the second colour is ≥5.

4. The method according to claim 1 wherein the at least one pigment has a L* value L*Pigment of ≥60 according to the CIE L* a* b* system, and optionally, wherein the at least one pigment has a surface zeta potential of ≥±15 mV.

5. The method according to claim 1 wherein the at least one pigment has a core-shell structure, wherein the core comprises an inorganic and/or organic material, and wherein the shell comprises at least one cationic polymeric shell layer different to the material of the core.

6. The method according to claim 5 , wherein the core comprises an inorganic material selected from the group consisting of titanium dioxide (CI 77891), black iron oxide (CI 77499), yellow iron oxide (CI 77492), red and brown iron oxide (CI 77491), manganese violet (CI 77742), ultramarine (sodium aluminium sulfosilicates, CI 77007, Pigment Blue 29), chromium oxide hydrate (CI 77289), Prussian blue (ferric ferrocyanide, CI 77510), carmine (cochineal), zinc sulfide, barium sulfate, zinc oxide, siliconised titanium dioxide, siliconised zinc sulfide, siliconised zinc oxide, and mixtures thereof.

7. The method according to claim 1 , wherein step B) further comprises

B2) applying a composition B2 comprising one or more anionic polymer(s) to the second portion of the hair after step B 1).

8. The method according to claim 7 , wherein the cationic polymer(s) are selected from the group consisting of polyethyleneimine, polyallylamine hydrochloride, polyvinylarnine, copolymers thereof and mixtures thereof.

9. The method according to claim 7 , wherein the anionic polymer(s) are selected from the group consisting of polystyrene sulfonate salts, λ-carrageenan salts, dextran sulfate salts, polyacrylic acid salts, poly(methacrylic acid) salts, alginic acid salts, carboxymethylcellulose salts, polystyrene sulfonate/polystyrene copolymer salts, polystyrene sulfonate/maleic acid copolymers salt, copolymers thereof and mixtures thereof.

10. The method according to claim 1 , further comprising, after step A):

C) colouring the hair by applying hair colouring composition(s) to at least a third portion of the hair, wherein the first and third portions of the hair have at least one second common area, wherein optionally , the hair colouring composition(s) comprise coloured polymer(s).

11. The method according to claim 10 , wherein step C) comprises C1) applying a composition C1 comprising one or more cationic polymer(s), to the third portion of the hair, wherein optionally the cationic polymer(s) are cationic coloured polymer(s), and/or

C2) applying a composition C2 comprising one or more anionic polymer(s) to the third portion of the hair after step C1), wherein optionally , the anionic polymer(s) are anionic coloured polymer(s).

12. The method according to claim 11 , wherein the cationic coloured polymer(s) and/or the anionic coloured polymer(s) comprise at least one chromophore and/or at least one fluorophore, wherein the chromophore(s) are selected from the group consisting of nitrobenzene, azo, imine, hydrazine, phenothiazine, xanthene, phenanthridine, phthalocyanin and triarylmethane-based dyes, derivatives thereof, derivatives obtained from direct dyes containing a carbonyl group, acridone, benzoquinone, anthraquinone, naphthoquinone, benzanthrone, anthranthrone, pyranthrone, pyrazolanthrone, pyrimidinoanthrone, flavanthrone, indanthrone, flavone, (iso)violanthrone, isoindolinone, benzimidazolone, isoquinolinone, anthrapyri done, pyrazoloquinazolone, perinone, quinacridone, quinophthalone, indigoid, thioindigo, naphthalimide, anthrapyrimidine, diketopyrrolopyrrole and coumarin dyes, derivatives thereof and mixtures thereof, and the fluorophore(s) are selected from the group consisting of derivatives from di-, tetra- or hexa-sulfonated triazine-stilbenes, coumarins, imidazolines, diazoles, triazoles, benzoxazolines, biphenyl-stilbenes optical brighteners, and mixtures thereof.

13. The method of claim 1 wherein the at least one pigment has a core-shell structure comprising:

a core comprising an inorganic and/or organic material, and

a shell comprising at least one cationic polymeric shell layer different to the material of the core, the shell at least partially encompassing the core.

14. A kit for treating hair comprising:

a first component comprising a composition A comprising a pigment as defined in claim 1 , wherein application of the pigment to a portion of hair having a first initial colour imparts a second colour different from the first color, and wherein the difference between the L* value of the second colour and the L* value of the first initial colour L* second colour −L* initial first colour is ≥1, according to the CIE L* a* b* system:

a second component comprising a composition B1 including one or more cationic polymers; and

a third component comprising a coloring composition C.

15. The kit of claim 14 , wherein the second component further comprises a composition B2 including one or more anionic polymers.

16. A method for treating hair comprising:

A) applying a composition A comprising at least one pigment to a first portion of the hair having a first initial colour to impart the first portion of the hair with a second colour different to the first initial colour, wherein the difference between the L* value of the second colour and the L* value of the first initial colour L* second colour −L* initial first colour is ≥1, according to the CIELAB color space (“CIE L* a* b*”) system; and

B) prior to step A), providing in at least a second portion of the hair one or more polymeric sublayers, wherein the first and second portions of the hair have at least one first common area, and applying at least one composition B1 comprising one or more cationic polymers to the second portion of the hair; and

C) colouring the hair by applying at least one hair colouring composition to at least a third portion of the hair, wherein the first and third portions of the hair have at least one second common area, and wherein at least one the hair colouring composition comprises one or more coloured polymers.

17. The method according to claim 16 , wherein step B) further comprises:

B2) applying a composition B2 comprising one or more anionic polymers to the second portion of the hair after step B1).

18. The method according to claim 16 , wherein step C) comprises:

C1) applying a composition C1 comprising one or more cationic polymers to the third portion of the hair; and

C2) applying a composition C2 comprising one or more anionic polymer(s) to the third portion of the hair after step C1),

wherein at least one of the one or more cationic polymers and the one or more anionic polymers comprises a coloured polymer.

19. The method according to claim 18 , wherein the at least one pigment has a D 50 particle diameter of 20 nm to 1 μm.