Bleaching composition

Abstract

The present invention relates to a bleaching composition for keratin fibres, especially human hair, comprising at least one compound with bleaching effect and two different silicate based alkalizing agents.

Claims

1. A substantially water free composition for bleaching keratin fibers, the composition comprising: one or more persalts; one or more metasilicate salts; and one or more disilicate salts, wherein a total concentration by weight of the one or more metasilicate salts is higher than a total concentration by weight of the one or more disilicate salts.

2. The composition according to claim 1 wherein the one or more persalts are selected from ammonium persulfate, sodium persulfate, and potassium persulfate.

3. The composition according to claim 1, wherein the one or more persalts are comprised at a total concentration of at least 5% by weight, calculated to a total weight of the composition.

4. The composition according to claim 1, wherein the total concentration of the one or more metasilicate salts and the one or more disilicate salts is in the range of 2 to 30% by weight, calculated to a total weight of the composition.

5. The composition according claim 1, wherein the one or more metasilicate salts and the one or more disilicate salts are present at a weight ratio of 10:1 to 1.1:1.

6. The composition according to claim 1, further comprising one or more ammonium salts that are different from the one or more persalts, the one or more metasilicate salts, and the one or more disilicate salts.

7. The composition according to claim 1, further comprising one or more cationic polymers.

8. The composition according to claim 1, further comprising one or more dicarboxylic acids, its salts, or at least one mixture thereof.

9. The composition according to claim 1, further comprising one or more chelating agents.

10. The composition according to claim 1, further comprising one or more thickening polymers.

11. The composition according claim 1, wherein the composition is in the form of a powder, a paste, or a suspension, and further comprises one or more oily lipophilic compounds.

12. The composition according to claim 1, further comprising one or more inert pulverulent carrier materials.

13. The composition according to claim 1, further comprising one or more direct dyes.

14. A method of bleaching hair comprising: mixing the substantially water free composition according to claim 1 with an aqueous composition to form a mixture, wherein the aqueous composition comprises one or more oxidizing agent and has a pH in the range of 1 to 5, and a weight ratio of the aqueous composition to the substantially water free composition is from 3:1 to 1:3; applying the mixture onto hair and leaving the mixture on the hair for 5 to 45 minutes; and subsequently rinsing the mixture off from the hair.

15. A kit comprising: the substantially water free composition according to claim 1; and an aqueous composition comprising one or more oxidizing agents and having a pH in the range of 1 to 5.

Description

EXAMPLE 1

(1) TABLE-US-00001 Concentration % by weight A B C Potassium persulfate 40 40 40 Sodium persulfate 5 5 5 Ammonium carbonate 1 1 1 Sodium metasilicate 10 7.5 15 Sodium disilicate 5 7.5 — Diatomaceous Earth 39 39 39

(2) The composition A is according to the present invention and the compositions B and C are comparative compositions in order to show the effect of the invention.

(3) The above compositions were prepared by combining all powder components together and mixing until homogeneity in a suitable mixer.

(4) The above bleaching powder compositions were mixed with the following oxidizing composition at a weight ratio of powder to oxidizing lotion 1:2.

(5) Oxidizing Lotion

(6) TABLE-US-00002 Hydrogen peroxide 9.00 (% by wt.) Phosphoric acid 0.50 Disodium hydrogen phosphate 0.10 Salicylic acid 0.10 Water ad 100.00

(7) After obtaining a homogeneous mixture, it was applied onto hair having colour at level 6, left on the hair for 30 min at ambient temperature and rinsed off with water. The hair was shampooed once and dried with a hair drier. The colour of the streaks were measured before and after bleaching with a laboratory colorimeter of the brand Minolta. The obtained values were used to calculate the colour differences with the well-known equation in the art.

(8) Hair damage was assessed by measuring the elasticity of individual hair fibres with stress strain technique. Therefore, 25 individual hair fibres with the length of 30 mm were wet with water and strained at a 100%/minute using MTT680 instrument (Dia-Stron Limited, Andover, UK). The force to strain hair fibre at 2% were obtained in MPa. The higher number indicates the less damage of the hair. The damage values were calculated as the reciprocal of the strain force at 2%. Afterwards, the damage per bleaching level was calculated by dividing the damage value with the DL, the intensity difference between unbleached hair and bleached hair.

(9) Following results were obtained.

(10) TABLE-US-00003 Force at 2% Composition L value ΔL (MPa) Damage Damage/ΔL A 40.1 21.02 47.01 0.021 0.0010 B 38.8 19.01 45.44 0.022 0.0012 C 35.7 15.9 45.92 0.022 0.0014

(11) Form the above results; it is beyond any doubt that the composition A causes the lowest damage to the hair. Furthermore, the bleaching effect of the composition A is the highest as well. In other words, the composition A delivered the most intensive bleaching effect with the least damage to the hair.

EXAMPLE 2

(12) TABLE-US-00004 Hydroxyethylcellulose 1.00% by weight Cellulose gum 3.00 Tetrasodium EDTA 2.00 Ammonium carbonate 1.00 Ammonium persulfate 21.00 Potassium persulfate 35.00 Sodium metasilicate 10.00 Sodium disilicate 5.00 Diatomaceous Earth 20.00 Polyquaternium - 10 1.00 Malic acid 1.00

(13) The hair was intensively bleached with the above composition with less hair damage.

EXAMPLE 3

(14) TABLE-US-00005 Hydroxyethylcellulose 1.00% by weight Cellulose gum 3.00 Tetrasodium EDTA 2.00 Ammonium carbonate 1.00 Ammonium persulfate 21.00 Potassium persulfate 35.00 Sodium metasilicate 10.00 Sodium disilicate 5.00 Kaolin 10.00 Paraffin oil 10.00 Polyquaternium - 10 1.00 Malic acid 1.00

(15) The above composition is a dust free powder bleach composition showing similar bleaching effect with the previous examples.