Process for treating keratin fibres with a composition comprising an amino acid

Abstract

The present invention relates to a process for treating keratin fibers, in particular the hair, comprising: a) the application, to said fibers, of a composition having a pH greater than or equal to 8, at 25 C., and comprising at least one amino acid chosen from those of formulae (I) and (II) below, and also the betaine forms thereof, the optical isomers thereof, the solvates thereof such as the hydrates, and the organic or inorganic base or acid salts thereof: in which formulae (I) and (II): R represents a hydrogen atom, or a linear or branched, preferably linear, C.sub.1-C.sub.5 alkyl group, said alkyl group being optionally substituted with at least one group chosen from hydroxyl, C(O)OH, S(O).sub.2OH, C(O)O.sup., M.sup.+, and S(O).sub.2O.sup., M.sup.+, with M.sup.+ representing a cationic counterion such as an alkali metal, alkaline-earth metal, or ammonium, n is 0 or 1;
b) followed by a step of straightening/relaxing the keratin fibers by means of a straightening iron at a temperature of at least 100 C. ##STR00001##

Claims

1. A method for treating keratin fibers, comprising: a) applying to the keratin fibers a composition, the composition comprising: at least one amino acid chosen from those according to formulae (I) and (II) below, the betaine forms thereof, the optical isomers thereof, the solvates thereof, or the organic or inorganic base or acid salts thereof: ##STR00009## wherein: R is chosen from hydrogen or a linear or branched, C.sub.1-C.sub.5 alkyl group, optionally substituted with at least one group chosen from hydroxyl, C(O)OH, S(O).sub.2OH, C(O)O.sup., M.sup.+, or S(O).sub.2O, wherein M.sup.+ is a cationic counterion, and n is equal to 0 or 1, wherein the pH of the composition is greater than or equal to 8, at a temperature of 25 C.; and b) straightening/relaxing the keratin fibers by means of a straightening iron at a temperature of at least 100 C.

2. The method according to claim 1, wherein the composition further comprises at least one basifying agent or at least one acidifying agent.

3. The method according to claim 2, wherein the at least one basifying agent is chosen from sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, or magnesium hydroxide.

4. The method according to claim 2, wherein the at least one basifying agent is chosen from the conjugated bases of the amino acids of formulae (I) or (II) according to formulae (Ib) and (IIb), below: ##STR00010## wherein: R is chosen from hydrogen or a linear or branched, C.sub.1-C.sub.5 alkyl group, optionally substituted with at least one group chosen from hydroxyl, C(O)OH, S(O).sub.2OH, C(O)O.sup., M.sup.+, or S(O).sub.2O.sup., M.sup.+ is a cationic counterion, and n is equal to 0 or 1.

5. The method according to claim 2, wherein the at least one acidifying agent is chosen from an inorganic acid or an organic acid.

6. The method according to claim 2, wherein the at least one acidifying agent is chosen from hydrochloric acid, orthophosphoric acid, sulfuric acid, citric acid, lactic acid, glycolic acid, gluconic acid, tartaric acid, or malic acid.

7. The method according to claim 1, wherein the at least one amino acid is chosen from the amino acids according to formula (I), the betaine forms thereof, the optical isomers thereof, the solvates thereof, or the organic or inorganic base or acid salts thereof.

8. The method according to claim 1, wherein the composition comprises: the at least one amino acid chosen from those according to formulae (I) and (II), and at least one basifying agent chosen from the conjugated base of the at least one amino acid according to formulae (Ib) or (IIb) below: ##STR00011## wherein: R is chosen from hydrogen or a linear or branched, C.sub.1-C.sub.5 alkyl group, optionally substituted with at least one group chosen from hydroxyl, C(O)OH, S(O).sub.2OH, C(O)O.sup., M.sup.+, or S(O).sub.2O.sup., M.sup.+ is a cationic counterion, and n is equal to 0 or 1.

9. The method according to claim 8, wherein the molar ratio of the at least one amino acid according to formulae (I) or (II) to its conjugated base according to formulae (Ib) or (IIb) ranges from about 1 to about 100.

10. The method according to claim 1, wherein the at least one amino acid is neutral or acidic.

11. The method according to claim 1, wherein the at least one amino acid is chosen from glycine, alanine, serine, beta-alanine and taurine, or the salts thereof.

12. The method according to claim 1, wherein the at least one amino acid is present in the composition in an amount ranging from about 1.5% to about 15% by weight, relative to the total weight of the composition.

13. The method according to claim 1, wherein the pH of the composition is less than two units from the pKa of the equilibrium of the at least one amino acid of formula (I) or (II) with its conjugated base (Ib) or (IIb).

14. The method according to claim 1, wherein the pH of the composition ranges from 8 to 12.

15. The method according to claim 1, wherein the composition further comprises at least one amino denaturing agent.

16. The method according to claim 1, wherein the composition further comprises at least one thickener.

17. The method according to claim 1, wherein the composition further comprises at least one additional ingredient chosen from non-ionic surfactants or silicones.

18. The method according to claim 1, wherein the straightening/relaxing step is carried out by means of a straightening iron at a temperature ranging from about 100 C. to about 300 C.

19. The method according to claim 1, wherein the straightening/relaxing step is carried out by means of a straightening iron at a temperature ranging from about 150 C. to about 250 C.

Description

EXAMPLES

(1) The following compositions were prepared from the ingredients indicated in the tables below, all the amounts being indicated as percent by weight of material in the given form, relative to the total weight of the composition.

(2) TABLE-US-00001 A 1 2 3 (control) Glycine 10.0 (1.33M) 5.0 (0.66M) 2.0 (0.27M) Sodium glycinate 10.0 (1.03M) 5.0 (0.51M) 2.0 (0.2M) Monoethanolamine 1.67 (0.27M) Hydrochloric acid qs pH Water qs 100 qs 100 qs 100 qs 100 pH 9.9 9.9 9.9 9.9 Relaxation after 10 ++++ ++++ +++ shampooing operations ++++: very strong relaxation +++: strong relaxation ++: medium relaxation +: a little relaxation : very little relaxation : no relaxation

(3) Compositions 1 to 3 according to the invention and control composition A were applied to locks of dry, curly, natural caucasian hair, of 2.7 g and 20 cm long with 5 to 7 curls. After 30 minutes, the hair was dried with a hairdryer (blow-drying) and then straightened by treatment with flat tongs heated to 210 C. (10 passes per lock). The hair was then subjected to 10 shampooing operations.

(4) For each lock, the curl relaxation was measured, namely the difference in lock length before and after treatment (including the 10 shampooing operations). It is noted that, with the process of the invention in which composition 1, 2 or 3 was applied, a strong or very strong curl relaxation is obtained after 10 shampooing operations, whereas, when control composition A is used, no relaxation is obtained.

(5) In addition, the treated locks retain good integrity, since no breaking was observed with compositions 2 and 3 and very slight breaking, after combing, was observed with composition 1.

(6) The process according to the invention thus makes it possible to obtain good long-lasting curl relaxation, while limiting the degradation of the hair.

(7) The following compositions 4 to 7 according to the invention and control composition B were also applied according to the previously described protocol and the same measurements as previously were carried out.

(8) TABLE-US-00002 B 4 5 6 7 (control) Glycine 3.5 (0.47M) 2.5 (0.33M) 5.0 (0.67M) 2.0 (0.27M) Sodium hydroxide at 3.5 (0.26M) 1.5 (0.11M) 5.0 (0.51M) 2.0 (0.15M) 2.0 (0.15M) 30% AM Ethanol 10.0 Methylhydroxyethyl- 1.0 1.0 cellulose (STRUCTURE CEL 8000 M from Akzo Nobel) Amodimethicone 2.0 (and) Trideceth-5 (and) Trideceth-10 (BELSIL ADM LOG 1 from Wacker) Water qs 100 qs 100 qs 100 qs 100 qs 100 pH 9.9 9.6 9.9 9.9 13.1 Relaxation after 10 + ++ +++ +++ + shampooing operations

(9) It is noted that, with the process of the invention in which composition 4 was applied, a little relaxation is obtained and with compositions 5 to 7, a medium-to-strong curl relaxation is obtained. It is also noted that, at equivalent sodium hydroxide molar content, a strong curl relaxation is obtained with composition 7 which comprises glycine, whereas only a little relaxation is obtained with control composition B which does not comprise glycine.

(10) The following composition 8 according to the invention and comparative composition C were also applied according to the previously described protocol and the same measurements as previously were carried out.

(11) TABLE-US-00003 C 8 (comparative) Glycine 8.8 (1.18M) Lysine 10.0 (0.68M) Sodium hydroxide at 8.8 (0.68M) 30% AM Guanidine hydrochloride 5.0 (0.52M) 5.0 (0.52M) Water qs 100 qs 100 pH 10.1 10.2 Relaxation after 10 ++++ + shampooing operations

(12) It is noted that, with the process of the invention in which composition 8 was applied, a significantly greater relaxation than with composition C at identical base content is obtained.

(13) The following compositions 9 and 10 according to the invention and comparative composition D were also applied according to the previously described protocol and the same measurements as previously were carried out.

(14) TABLE-US-00004 D 9 10 (comparative) Alanine 4.5 (0.5M) Serine 4.3 (0.5M) Lysine 7.3 (0.5M) Sodium hydroxide at 4.0 (0.3M) 4.5 (0.33M) 3.0 (0.22M) 30% AM Water qs 100 qs 100 qs 100 pH 10.1 10.0 11.1 Relaxation after 10 + ++ shampooing operations

(15) It is noted that, with the process of the invention in which compositions 9 and 10 were applied, a significantly greater relaxation than with composition D at equivalent molar content of amino acid is obtained.

(16) Finally, the following compositions 11 to 15 according to the invention and comparative composition E were also applied according to the previously described protocol and the same measurements as previously were carried out.

(17) TABLE-US-00005 E 11 12 13 14 15 (comparative) Glycine 3.5 3.5 3.5 3.5% 2.1 (0.47M) (0.47M) (0.47M) (0.47M) (0.28M) Sodium hydroxide at 3.5 3.5 3.5 3.5% 2.1 30% AM (0.26M) (0.26M) (0.26M) (0.26M) (0.16M) Monoethanolamine 1.0 (0.16M) Ethanol 10 10.0 10 10% Urea 5.0 10.0 15.0 15.0 (2.58M) (0.83M) (1.66M) (2.58M) Hydroxyethylurea 21.8 6.3 (0.83M) (0.24M) Amodimethicone (and) 2.0 2.0 2.0 2.0 Trideceth-5 (and) Trideceth-10 (BELSIL ADM LOG 1 from Wacker) Methylhydroxy- 1.0 1.0 1.0 1.0 ethylcellulose (STRUCTURE CEL 8000M from Akzo Nobel) Water qs 100 qs 100 qs 100 qs 100 qs 100 qs 100 pH 9.9 9.9 9.9 9.9 10.0 11.9 Relaxation after 10 +++ +++ ++++ ++++ ++++ ++ shampooing operations

(18) It is noted that, with the process of the invention in which compositions 11 to 15 were applied, a strong to very strong curl relaxation is obtained. It is also noted that, with composition 15, a significantly greater relaxation than with composition E is obtained, at identical base content, and this with a pH of composition 15 according to the invention which is lower than that of comparative composition E.