DE29722990U1 - Means for bleaching and lightening human hair - Google Patents

Description

Products for bleaching and lightening human hair

The present invention relates to an agent for bleaching human hair with improved lightening and decolorizing effects.

Conventional agents for bleaching human hair consist of at least one solid peroxide, in particular a persulfate, and a powdered carrier material. This powder is mixed with a 6 to 12 percent hydrogen peroxide solution and applied to the hair. Examples of such compositions can be found in the relevant specialist literature, for example in K. Schrader, "Grundlagen und Rezepturen der Kosmetika", 2nd edition (1989, Hüthig Buchverlag), pp. 815 to 823.

However, the lightening properties of these bleaching powders have not always been satisfactory, especially when it comes to decolorizing colored or tinted hair. There was therefore a need to develop bleaching agents with an improved lightening effect.

It has now been found that an agent for bleaching human hair with improved lightening and decolorizing effect is obtained if this agent contains at least one guanidine salt.

When mixed with a hydrogen peroxide solution, the bleaching agent thus composed produces an excellent lightening effect on the hair, which is significantly improved compared to conventional bleaching agents.

-2-

The water-soluble guanidine salts used are preferably the hydrochloride, carbonate and hydrogen carbonate, but of course other inorganic and organic guanidine salts such as nitrates, sulfates, phosphates, acetates, formates, tartrates, succinates or citrates are also suitable.

From DE 27 04 905 A1, agents for bleaching hair based on peroxide oxidizing agents and ammonia-free alkalizing agents are already known, which contain organic guanidine derivatives, in particular alkylenebisguanidinium or aminoalkylguanidinium salts, as bleaching accelerators. These compounds have a much more complicated structure than the guanidine salts used in the invention, which are also readily available commercially and are therefore much more cost-effective.

Although the guanidine salt can also be used alone in a mixture with hydrogen peroxide, according to a preferred embodiment of the invention it is used as a powder in a mixture with peroxides and optionally carriers.

The preferred amount used in such a powder is about 1 to about 90% by weight, in particular about 10 to about 50% by weight, especially about 15 to about 35% by weight, calculated on the total composition of the lightening or bleaching powder and guanidine as a free base.

In the ready-to-use mixture prepared with aqueous hydrogen peroxide, the proportion of guanidine salt is preferably about 1 to about 25% by weight, in particular about 2.5 to 15% by weight, based on the ready-to-use product.

The addition of the guanidine salts is carried out by simple mixing when it comes to simple powder compositions of the type described, for example, by Schrader, I.e.

According to a preferred embodiment of the invention, the bleaching and lightening powders are used as dust-free products that are present as granules or agglomerates.

-3-

These may, for example, be the products described in EP-A 560 088, which contain an oil or a liquid wax, whereby the application of this oil or wax is expediently carried out by spraying.

Dust-free bleaching powders which were produced in accordance with EP-A 630 643 by agglomerating the powdered starting components by spraying on melted waxes or C10-C18 fatty acid alkanolamides or fusing them with them at an elevated temperature are also suitable according to the invention.

The agent according to the invention for bleaching human hair contains the known and usual components in such agents; in order to avoid repetition, reference is made to Schrader, I.e., whereby in addition to powders, suspensions, emulsions, etc. can also be used as carrier systems.

Suitable brightening, bleaching-active substances are peroxides, preferably alkali persulfates such as potassium, sodium and ammonium persulfate, magnesium peroxide, urea peroxide, melamine peroxide, etc. and mixtures thereof. The ammonium persulfate-free bleaches based on sodium/potassium persulfate described in EP 815 830 A2 are also suitable. However, compositions can also be used which contain no or only small amounts of persulfate and instead other brightening components, for example ammonium carbonate, ammonium bi-

carbonate, ammonium carbamate, ammonium chloride, ammonium sulfate, ammonium phosphates, ammonium bromide, ammonium iodide, ammonium nitrate, ammonium thiosulfate, ammonium molybdate, ammonium vanadate, ammonium sulfamate, ammonium citrate, ammonium salicylate, ammonium valerate, ammonium tartrate, ammonium benzoate, ammonium acetate, ammonium formate and/or ammonium lactate.

The proportion of per compounds is preferably between about 5 and about 75, in particular about 25 and about 60% by weight, based on the lightening and bleaching powder.

The particle sizes of the bleaching agents according to the invention are generally below 1 mm, preferably below 500 microns, for example less than 400 microns, in particular about 25 to about 100 μm, which ensures excellent processability, i.e. miscibility with water or an aqueous hydrogen peroxide solution before application to the human hair.

The product is used in a known and usual way:

The powdered lightening agent is homogeneously mixed with a 6 to 12 percent hydrogen peroxide solution, preferably in a ratio of about 1 part by weight of the powder to about 0.5 to about 4, in particular about 1 to about 2.5 parts by weight of the peroxide solution or lotion, preferably 6% H2O2 solution or lotion, and then applied to the hair for about 20 to about 60 minutes, depending on the temperature.

-5-

The application can also be done by mixing the bleaching powder and the hydrogen peroxide solution in a cream base and then applying this homogeneous mixture to the hair.

The proportion of guanidine salt, calculated as free base in the ready-to-use total product, i.e. the mixture of brightening agent and aqueous H202 preparation, is preferably about 0.5 to about 15, in particular about 1 to about 10% by weight of the mixture; the pH value of the mixture is in the range between about 8 and about 11.5, preferably about 9 to about

The following examples serve to illustrate the invention.

example 1

a) Whitening powder

Silicon dioxide 15.8 (wt.%)

Ammonium chloride 4.7

Guanidine carbonate 25.0

Sodium metasilicate 2,3

Sodium persulfate 52.2

This composition is mixed in a weight ratio of 1:2.5:2.5 with an H202 lotion b) and a cream base c):

b) Hydrogen peroxide lotion

Al/98 -6-

Hydrogen peroxide 6.0 (wt.%) Cetylstearyl alcohol 1.7 phosphoric acid 0.5 Sodium lauryl sulfate 0.2 Disodium hydrogen phosphate 0.1 Salicylic acid 0.1 Water to 100.0 c) Cream base Cetylstearyl alcohol 11.0(Weight-S Oleth-5 5.0 Oleic acid 2.5 Stearamide MEA 2.3 Cocoamide MEA 2.3 Sodium cetylstearyl sulfate 1.2 1,2-propylene glycol 1.0 1,2-Propylene glycol stearate 0.6 Sodium lauryl sulfate 0.5 Wheat protein hydrolysate 0.9 Panthenol 0.6 Perfume 0.4 Complexing agents 0.2 Water to 100.0

The pH value of this mixture was 9.3.

This mixture (A) was applied to dyed human hair strands and, after exposure for 30 minutes at 30 ^° C, was washed out, dried and the lightening achieved was determined in comparison with a composition B which did not contain guanidine carbonate but instead contained inert silicon dioxide, and with the initial value.

The brightening values were determined using the color measuring device "Cromameter CR 200" from Minolta.

The value for the untreated colored strand was set at 100; the measured value for the lightened strands is related to this.

The CRP (Color Removal Power) is a measure of the reduction in color intensity in percent compared to the original colored strand, which is set at 100%. This means that the higher the CRP value, the greater the lightening and color reduction.

These results show that with the composition A according to the invention, a significantly better lightening was achieved in all colorations compared with the non-inventive composition B.

Table I CRP values

composition B Dyed hair A 48.3 With direct puller Basic Red 2 71.8 40.2 With oxidation dye mixture of 2.5-
Diaminotoluene, 4-aminophenol and 4-amino-2-
methylphenol 49.5

-8- Example 2

a) Whitening powder

Silicon dioxide 20.0 (wt.%) Sodium metasilicate 5.3

Hydroxyethylcellulose 5.2

Sodium persulfate 5.3

Potassium persulfate 54.0

Guanidine hydrochloride 10.2

This composition was mixed with a H202 lotion b) and a cream base c) in a weight ratio of 4.8:4:3, obtaining a mixture with a pH of 10.6.

b) Hydrogen lotion

Hydrogen peroxide 12.0(wt%) Cetylstearyl alcohol 1.7 phosphoric acid 0.3 Sodium lauryl sulfate 0.2 Disodium hydrogen phosphate 0.1 Salicylic acid 0.1 Water to 100.0

c) Cream base 11.0 Cetylstearyl alcohol 5.0 Oleth-5 2.5 Oleic acid 2.3 Stearamide MEA 2.3 Cocoamide MEA 1.2 Cetylstearyl sulfate 0.5 Sodium lauryl sulfate 1.0 1,2-propylene glycol 0.6 1,2-Propylene glycol mono/distearate 12.0 Monoethanolamine q.s. Complexing agent, perfume 0.5 Ultramarine blue to 100.0 Water

The application and evaluation of the mixture A composed according to the invention and an identical composition B, which however did not contain guanidine hydrochloride, was carried out as described in Example 1.

Table II CRP values Result :

Dyed hair composition B A 32.36 With direct puller base Red 2 47.98 64,64 With oxidation dye mixture of 2.5-
Diaminotoluene, 4-aminophenol and 4-amino-
2-methylphenol 72.16

This clearly results in the significantly stronger lightening and decolorizing effect of the composition according to the invention.

Whitening powder

-10-

Example 3

Silicon dioxide

Hydroxyethylcellulose

Carboxymethylcellulose

Sodium lauryl sulfate

Protein hydrolysate

Sodium stearate

Strength

sodium

Ultramarine blue

Magnesium peroxide

Sodium metasilicate

Potassium persulfate

Polyvinylpyrrolidone

Sodium alginate

Cocomonoethanolamide

Oleamide

Perfume oil

Polyorganosiloxane

(Dimethicone copolyol)

Guanidine hydrochloride

l,2(wt.%)

1.4

2.5

2.5

0.5

1.0

1.0

1.1 0.2 4.0 9.0 48.0 4.0 0.4 8.0 2.0 0.5 0.5

12.2

This powder was mixed homogeneously with a 6% hydrogen peroxide solution and applied to human hair.

After thirty minutes of exposure at room temperature, extensive lightening and decolorization of red-dyed hair was achieved.

Claims (4)

A-l/98 U Protection claims 1. Agent for bleaching and lightening human hair, containing at least one water-soluble guanidine salt. 2. Powdered agent according to claim 1, containing about 1 to about 90% by weight of at least one water-soluble gunidine salt and at least one powdered carrier material and/or a peroxide. 3. Agent according to claim 2, containing sodium and/or potassium persulfate as peroxide. 4. Powdered agent according to one of claims 2 or 3, containing 5 to 75% by weight of at least one peroxide, calculated on the total composition of the powder.