Method for dyeing keratin fibers with a dye compositions containing at least one direct dye and at least one basifying agent

A method for dyeing keratin fibers such as human hair by applying to the fibers a dye composition, in particular a lightening dye composition, containing, in a medium which is suitable for dyeing, at least one direct dye to be mixed at the time of use, at basic pH, with an oxidizing agent, wherein the dye composition a has a basic pH and contains, as direct dye, at least one dye containing an optionally delocalizable quaternized nitrogen atom and a --Z.dbd.N-- bond in which Z denotes a nitrogen atom or a --CH-- radical. The invention is also directed to a ready-to-use composition and a multi-compartment dyeing device for dyeing keratin fibers.

The present invention relates to a dye composition, in particular a 
lightening dye composition, for keratin fibers, and in particular human 
keratin fibers, comprising at least one direct dye chosen from the group 
formed by dyes containing an optionally delocalizable quaternized nitrogen 
atom and a --Z.dbd.N-- bond, in which Z denotes a nitrogen atom or a 
--CH-- radical. The invention also relates to the use of such a 
composition in the above-mentioned application. 
It is known to dye keratin fibers, and in particular human hair, with dye 
compositions containing direct dyes according to a so-called "direct 
dyeing" process. This process involves applying to the keratin fibers dye 
molecules that have an affinity for the fibers, leaving the fibres to 
stand, and then rinsing the fibers. This process allows shading of the 
color of the keratin fibers to be obtained. It is also known to dye 
keratin fibers, and in particular human hair, with dye compositions 
containing oxidation dye precursors (ortho- or para-phenylenediamines and 
ortho- or para-aminophenols, generally referred to as "oxidation bases") 
and couplers (meta-phenylenediamines, meta-aminophenols and 
meta-diphenols, also referred to as color modifiers, which allow the 
"base" colors obtained by the condensation products of the oxidation bases 
to be modified and enriched with glints), according to a so-called 
"oxidation dyeing" process. 
The oxidation dyeing process usually involves lightening, that is to say 
that it involves applying to the keratin fibers, at basic pH, a mixture of 
bases and couplers and aqueous hydrogen peroxide solution, leaving the 
applied mixture to stand on the hair and then rinsing the hair. It allows, 
particularly in the case of hair dyeing, the melanin to be lightened and 
the hair to be dyed. 
Lightening the melanin has the advantageous effect of creating a unified 
coloration in the case of grey hair, and, in the case of naturally 
pigmented hair, of bringing out the color, that is to say of making it 
more visible. 
An oxidizing agent and, in particular, an aqueous hydrogen peroxide 
solution, and a basifying agent are used to obtain this lightening. A 
lightening of the melanin ranging from 3/4 of a tone to more than 2 tones 
can be brought about as a function of the concentrations of aqueous 
hydrogen peroxide and of basifying agent, and also as a function of the 
nature of the basifying agent. In the case of gentle lightenings, the 
desired lightening is obtained in the course of superpositions. 
In the so-called oxidation dyeing of hair, the use of oxidation bases 
sometimes leads to problems of sensitization of the scalp. In this case, 
if it is nevertheless desired to dye the hair, it is then possible only to 
use direct dyeing, with its drawbacks, in particular that of no longer 
obtaining the tinting effects of oxidation dyeing since conventional 
direct dyeing is, by itself, not lightening. 
It has already been attempted in the past to obtain lightening dyes, by 
replacing the oxidation bases and the couplers with direct dyes. However, 
all the results obtained were less than optimal. 
Accordingly, it was proposed to dye the hair with dye compositions based on 
nitro direct dyes and/or dispersed azo dyes and ammoniacal aqueous 
hydrogen peroxide (see in this respect French patent no. FR-1,584,965 and 
Japanese patent no. JP-062,711,435) by applying to the hair a mixture of 
the dyes and the oxidizing agent, which is prepared just before use. 
However, the colorations obtained did not prove to be sufficiently fast 
and disappeared on shampooing, allowing the lightening of the hair fibre 
to emerge. Such a coloration becomes aesthetically unpleasant by changing 
over time. 
It has also been proposed to dye the hair with compositions based on 
cationic direct dyes of oxazine type and ammoniacal aqueous hydrogen 
peroxide (see in this respect Japanese patents JP-53 95693 and JP-55 
022638) by applying to the hair, in a first step, ammoniacal aqueous 
hydrogen peroxide, and then, in a second step, a composition based on the 
oxazine direct dye. The coloration obtained is not satisfactory, on 
account of the fact that it requires a process which is made too slow by 
the standing times of the two successive steps. If, moreover, a mixture, 
prepared at the time of use, of the oxazine direct dye with ammoniacal 
aqueous hydrogen peroxide is applied to the hair, the hair fibre is not 
dyed or, at best, a coloration which is virtually nonexistent is obtained. 
Moreover, the Inventor has performed tests to dye the hair with dye 
compositions based on anionic sulfonic dyes (which are themselves reputed 
for the excellent fastness) and on ammoniacal aqueous hydrogen peroxide, 
by applying to the hair a mixture of the dyes and the oxidizing agent, 
which is prepared just before use. However, in this case, no coloration of 
the hair fibre was observed. 
Now, after considerable research has been conducted in this direction, the 
Inventor has discovered that it is possible to obtain dyes, in particular 
lightening dyes, with specific and suitably selected direct dyes, which 
are fast, homogenous and do not change on washing, by using a mixture 
which is prepared at the time of use, at basic pH, of an oxidizing agent 
and at least one direct dye which is chosen from those containing both an 
optionally delocalizable quaternized nitrogen atom and a --Z.dbd.N-- bond, 
in which Z denotes a nitrogen atom or a --CH-- radical. This discovery 
forms the basis of the present invention. 
One subject of the present invention is thus a dye composition, in 
particular a lightening dye composition, for keratin fibers, and in 
particular for human keratin fibers such as the hair, of the type 
comprising, in a medium which is suitable for dyeing, at least one direct 
dye to be mixed at the time of use, at basic pH, with an oxidizing 
composition, and which is characterized in that it has a basic pH and in 
that it contains, as the direct dye, at least one dye containing an 
optionally delocalizable quaternized nitrogen atom and a --Z.dbd.N-- bond 
in which Z denotes a nitrogen atom or a --CH-- radical. 
The dyes used in accordance with the present invention make it possible to 
achieve homogenous and fast colorations which remain aesthetic over time, 
since they do not change either over time or on washing. They are 
furthermore produced very rapidly, and in particular in a standing time of 
the dye/oxidizing agent mixture of five minutes. In addition, they 
communicate an especially shiny appearance and a natural feel without 
overloading, in particular on hair fibers. 
Another subject of the present invention relates to a process for dyeing, 
and in particular lightening, keratin fibers, in particular human keratin 
fibers such as the hair, which involves applying to those fibers at least 
one composition (A) containing, in a medium which is suitable for dyeing, 
at least one direct dye containing an optionally delocalizable quaternized 
nitrogen atom and a --Z.dbd.N-- bond in which Z denotes a nitrogen atom or 
a --CH-- radical, the lightening being ensured, at basic pH, using an 
oxidizing agent which is mixed with the composition (A) just prior to use, 
or which is present in a separate composition (B) that is applied 
simultaneously. 
Another subject of the invention is multi-compartment dyeing devices or 
"kits", the first compartment of which contains at least one direct dye 
containing an optionally delocalizable quaternized nitrogen atom and a 
--Z.dbd.N-- bond in which Z denotes a nitrogen atom or a --CH-- radical, 
as well as a basifying agent, and the second compartment of which contains 
an oxidizing agent. Another alternative "kit" is composed of a first 
compartment containing at least one direct dye as mentioned above, a 
second compartment containing a basifying agent and a third compartment 
containing an oxidizing agent. 
The invention also relates to a "ready-to-use composition", characterized 
in that it contains, in a medium which is suitable for dyeing, at least 
one direct dye containing an optionally delocalizable quaternized nitrogen 
atom and a --Z.dbd.N-- bond, in which Z denotes a nitrogen atom or a 
--CH-- radical, an oxidizing agent and also, if necessary, a basifying 
agent in an amount which is sufficient to adjust the final pH to a value 
above 7, and preferably to a value ranging from 8.5 to 11. 
However, other characteristics, aspects, subjects and advantages of the 
invention will emerge even more clearly on reading the description and the 
examples which follow. 
The direct dyes containing an optionally delocalizable quaternized nitrogen 
atom and a --Z.dbd.N-- bond, in which Z denotes a nitrogen atom or a 
--CH-- radical, which may be used according to the invention are 
preferably chosen from the compounds of formula (I) below: 
##STR1## 
in which Z denotes a nitrogen atom or a --CH-- radical. A and B each 
independently denote an optionally substituted benzenic or heterocyclic 
aromatic group, wherein each of the aromatic groups is optionally 
substituted on any ring atom, including the ring atom bound to the Z or N 
moiety of formula (I). The aromatic groups are preferably substituted with 
one or more halogen atoms or with one or more radicals such as a methyl 
radical, a phenyl radical, an NR.sub.1 R.sub.2 radical or an OR.sub.1 
radical, in which R.sub.1 and R.sub.2, simultaneously or independently of 
each other, represent hydrogen, a C.sub.1 -C.sub.8 alkyl radical, a 
C.sub.1 -C.sub.8 hydroxyalkyl radical or a phenyl radical. X denotes an 
anion, preferably chloride or methyl sulphate, it being possible for the 
cationic charge to form an integral part of the aromatic ring or to be 
carried by one of its substituents. 
These dyes are well known in the prior art and are described in patent 
applications WO-95/01772 and WO-95/15144, the disclosures of which are 
incorporated herein by reference. 
Among the compounds of formula (I) which can be used in the context of the 
present invention, and whose cationic charge is carried by a substituent 
on one of the aromatic rings, it is preferred to use the compounds of the 
following formulae: 
##STR2## 
i.e., 4-aminophenylazo-2-hydroxy-8-trimethylammonio-naphthalone chloride; 
##STR3## 
i.e., 2-methoxyphenylaze-2-hydroxy-8-trimethylammonionaphthalene chloride; 
##STR4## 
i.e., 4-amino-3-nitrophenylazo-2-hydroxy-8-trimethylammonio-naphthalene 
chloride; and 
##STR5## 
i.e. 8-trimethylammoniophenylazo-N-phenyl-3-methyl-5-hydroxy-pyridazine 
chloride. 
According to the present invention, it is even more preferred to use 
compounds of formula (I) whose cationic charge forms an integral part of 
one of the aromatic rings. Among the compounds that may be mentioned, by 
way of non-limiting examples, are the compounds of the following formulae: 
##STR6## 
i.e., (1-methyl-1-phenyl)-2 (1-methine4N-methylpyrdinylium] hydrazine 
chloride; 
##STR7## 
i.e., (1-methyl-1-paramethoxyphenyl)-2-(1-methine-4N-methylpyridinylium) 
hydrazine chloride; 
##STR8## 
i.e., (1-methyl-1-paramethoxyphenyl)-2-(1-methine-4N-methylpyridinylium) 
hydrazine methylsulphate; 
##STR9## 
i.e., 4-dimethylaminophenylazo-2N-methyl-5N-methyl-imidazolylium chloride 
##STR10## 
i.e., 4-dimethylaminophenylazo-2N-methyl-3N-methyl-imidazolylium chloride; 
##STR11## 
i.e., 1 -methylaminophenylazo-2N-methyl-5N-methyl-imidazolylium chloride; 
##STR12## 
i.e., 4-aminophenylaze-2N-methyl-5N-methylimidazolylium chloride; 
##STR13## 
i.e., 4-dimethylaminophenylazo-4N-methyl-pyridinylium chloride; and 
##STR14## 
i.e., 4-dimethylaminophenylazo-4N-oxido-pyridinylium chloride. 
The concentration of direct dye(s) of formula (I) preferably ranges from 
0.001 to 5% by weight approximately relative to the total weight of the 
dye composition before it is mixed with the oxidizing agent, and more 
preferably ranges from approximately 0.05 to 2%. 
The oxidizing agent is preferably chosen from hydrogen peroxide, urea 
peroxide, alkali metal bromates and persalts such as perborates and 
persulphates. The use of hydrogen peroxide is particularly preferred. 
The pH of composition (A) which contains at least one direct dye of formula 
(I) as well as that of composition (B) containing the oxidizing agent as 
defined above are such that after mixing composition (A) with composition 
(B), the pH of the composition applied to the human keratin fibers is 
preferably above 7, and more preferably ranges from 8.5 to 11. The pH is 
preferably adjusted to the chosen value using basifying agents, or 
possibly acidifying agents, which are well known in the state of the art 
in the dyeing of keratin fibers. 
Basifying agents which may be mentioned are aqueous ammonia, alkaline 
carbonates, alkanolamines, for example mono-, di- and triethanolamines and 
derivatives thereof, sodium hydroxide, potassium hydroxide and compounds 
of formula (II): 
##STR15## 
in which R is a propylene residue optionally substituted with a hydroxyl 
group of a C.sub.1 -C.sub.4 alkyl radical, R.sub.3, R.sub.4, R.sub.5, and 
R.sub.6, simultaneously or independently of each other, represent a 
hydrogen atom, a C.sub.1 -C.sub.4 alkyl radical or a C.sub.1 -C.sub.4 
hydroxyalkyl radical. 
The acidifying agents are conventionally inorganic acids such as, for 
example, hydrochloric acid, tartaric acid, citric acid and phosphoric 
acid. 
The oxidizing composition (B) preferably comprises an aqueous hydrogen 
peroxide solution whose titre may range, more particularly, from 5 to 40 
volumes approximately. 
The basifying agent is preferably chosen from alkanolamines when moderate 
lightening is required, and it is more particularly represented by aqueous 
ammonia when more pronounced lightening is desired. 
The medium suitable for dyeing is preferably an aqueous medium comprising 
water and more preferably a water/solvent(s) mixture, the solvent(s) being 
chosen from organic solvents such as 2-butoxyethanol or ethanol. 
According to a preferred embodiment of the dyeing process of the invention, 
the dye composition (A) described above containing a basifying agent, and 
more particularly an aqueous solution of ammonia or of alkanolamine 
described above, is mixed, at the time of use, with an oxidizing solution 
in an amount which is sufficient to give rise to lightening of the 
melanin. The mixture obtained is then applied to human keratin fibers and 
is left standing on them preferably for 1 to 45 minutes, more preferably 
for 4 to 20 minutes, after which the fibers are rinsed, optionally washed 
with shampoo, rinsed again and dried. 
The dye compositions according to the invention also contain, in their 
preferred embodiments, surfactants which are well known in the art, in 
proportions ranging from approximately 0.5 to 55% by weight, and 
preferably from 2 to 50% by weight relative to the total weight of the 
composition, organic solvents, in proportions ranging from approximately 1 
to 40% by weight, and in particular from 5 to 30% by weight relative to 
the total weight of the composition, or any other cosmetically acceptable 
adjuvant known in the prior art in the oxidation dyeing of hair. 
The composition applied to the hair may be in various forms, such as in 
liquid, cream or gel form, or in any other form which is suitable for 
dyeing keratin fibers, and in particular human hair. In particular, it may 
be packaged under pressure in an aerosol can in the presence of a 
propellant and may form a foam.

Concrete examples illustrating the invention will now be given. These 
examples are not intended to limit the subject matter of the invention. 
EXAMPLES 
Example 1 
0.5% by weight of each of the following seven direct dyes was introduced 
into 10% by weight of a 20% aqueous ammonia solution, followed by addition 
of 100% by weight of 20-volumes aqueous hydrogen peroxide. 
Each of the seven compositions obtained above was then applied to locks of 
European, non-permanent-waved hair containing 90% white hairs, and the 
compositions were allowed to remain on the hair for 30 minutes. After 
rinsing the locks with running water, followed by drying, the coloration 
obtained was graded on a scale from 0 to 3, as follows: 
Grade 0--no coloration 
Grade 1--slightly perceptible but unacceptable coloration 
Grade 2--clearly perceptible coloration but at the limit of acceptability 
Grade 3--good coloration. 
The results obtained were as follows: 
Dyes not according to the invention: 
anionic sulfonic dye: 
Acid Black 1 (C.I. 20470).fwdarw.grade=0 
nitrobenzene dye: 
N1, N4, N4-tris(.beta.-hydroxyethyl)-1,4-diamino 
2-nitrobenzene.fwdarw.grade=1 
cationic dye of oxazine type: 
Basic Blue 3.fwdarw.grade=0 
cationic dye containing no --N.dbd.N or --CH.dbd.N-- function: 
1-(N-methylmorpholiniumpropylamino)-4-hydroxyanthraq uinone (methyl 
sulphate).fwdarw.grade=0 
Dyes according to the invention (the Nos. correspond to the products in the 
description): 
dye (8) with an --N.dbd.N-- function.fwdarw.grade=3 
dye (6) with a --CH.dbd.N-- function.fwdarw.grade=3 
Consequently, among the seven direct dyes studied, only the dyes according 
to the invention make it possible to obtain good lightening colorations. 
Example 2 
The following dye compositions were prepared: 
Direct dye of formula (I) according to the invention* . . . .times.g 
20% aqueous ammonia solution . . . 10 g 
Demineralized water . . . q.s. for 100 g *See Table (I) following page, the 
Nos. corresponding to the products in the description. 
In a first experiment (lightening dye according to the invention), locks of 
natural chestnut brown European hair were dyed with a mixture, prepared at 
the time of use, of the composition described above with its weight of 
20-volumes aqueous hydrogen peroxide. After allowing the composition to 
remain on the locks for 5 minutes, they were rinsed with running water and 
then dried. 
In a second experiment (comparative standard direct dyeing), other locks of 
hair (same quality as above) were separately dyed with a composition as 
described above, the only difference being that it contained no aqueous 
hydrogen peroxide. After allowing the composition to remain on the locks 
for the same length of time as for the above dyeing, they were rinsed and 
then dried. 
The lightening dyes according to the invention were thus compared with 
corresponding standard direct dyes, this being with the direct dyes (8), 
(10) and (10)+(7) of formula (I) according to the invention. 
The compared shades were measured in terms of L, a, b values (color 
notation system in which (L) denotes the intensity, (a) denotes the shade 
and (b) denotes the purity) on a Minolta CM2002 calorimeter. 
TABLE I 
__________________________________________________________________________ 
Dyeing with dye No. 
L,a,b L a b Comments 
__________________________________________________________________________ 
(8): 2 g invention 
22.44 
6.30 
1.52 
a increases .fwdarw. 
comparative 22.31 3.88 0.68 redder shade 
(10): 0.4 g + (7): 1.8 g invention 23.74 5.35 3.96 a and b increase 
.fwdarw. 
comparative 22.63 2.39 1.90 more orange shade 
(10): 2 g invention 22.60 6.67 2.53 a increases .fwdarw. 
comparative 22.21 3.83 1.33 redder shade 
control (no dye) 22.62 1.84 2.06 
__________________________________________________________________________ 
These results demonstrate that the lightening dyeing using the direct dyes 
according to the invention (with aqueous hydrogen peroxide) had better 
performance in terms of visual effect (generated more visible colorations) 
than standard direct dyeing with these same dyes (without aqueous hydrogen 
peroxide). 
These lightening dyeings gave colorations that were moreover homogeneous, 
fast and shiny and which remained aesthetically attractive over time. The 
hair also offered a natural appearance without overloading.