FIELD OF INVENTION

The present invention relates to an auto-oxidisable hair dye composition/ kit favouring optimal colour delivery due to the specific selection of primary intermediates and couplers together with alkalizers free of any developer/ oxidant for effective colouration of keratinous fibers. More particularly, the present invention relates to the selective alkalizer based auto-oxidisable hair dye composition/kit free of any developer/ oxidant in combination with specific primary ingredients and couplers to thereby favour optimal colour delivery when said selective alkalizer is present at defined pH level for effective colouration of keratinous fibers. Advantageously, the auto-oxidisable hair dye composition/ kit of the present invention further economizes on time and cost by favouring effective hair coloration by way of superior colour delivery and improved retention of colour even while not incorporating any developer/ oxidant other than the active ingredients in the formulation but instead incorporating selective alkalizers at a defined pH level, thereby rendering its safe usage in being free of oxidizing agents. Moreover, the said hair colouring composition/kit additionally includes other hair benefiting agents and is adapted for use in all cosmetically acceptable forms.

BACKGROUND ART

The color of the hair, the skin and hair of human origin originates mainly from the melanin pigments secreted by the melanocytes. These pigments of natural origin, comprise, in particular, pigments known as eumelanins and pheomelanins. Their natural bio-synthesis takes place in several stages by polymerization of the oxidation products of an aminoacid, namely tyrosine, and one of these oxidation products is 5,6-dihydroxyindole which, in turn, polymerizes to Eumelanin.

It has long been known that p-Phenylenediamine and p-toluenediamine are capable of coloring hair but the coloring process is very slow unless applied in combination with an oxidizing agent such as hydrogen peroxide which must be kept apart from these diamines until immediately prior to use and which often damages the hair. The process of hair coloring with primary intermediates like p- Phenylenediamine or p-toluenediamine is by their auto oxidation capabilities.

p-Phenyienediamine p-Benzoquinonediimine

The first step in the oxidation process is the oxidation of p-phenylene diamine (I) to the corresponding p-benzoquinonediimine (II). The electrophilic attack by the conjugate acid (V) of p-benzoquinonediimine on the carbon ring of a molecule of p-phenylenediamine results in the production of triaminodiphenylamine. Triaminodiphenylamine undergoes oxidation, followed by reaction with another molecule of the diamine to produce the trinuclear compound which is known as Bandrowski's base (VI).

The coloring process by auto oxidation of primary intermediates like p-Phenylenediamine or p-toluenediamine is very slow and may take several hours for dyeing grey hair. This process is speeded up by using oxidizing agents like Hydrogen peroxide which releases perhydroxyl anion and the entire coloring process is completed within 30-45 minutes wherein the primary intermediates like p-Phenylenediamine or p-toluenediamine react with couplers like resorcinol, m-aminophenol forming Indodyes.

The use of peroxides on hair is known to have damaging effects especially on the pore size and cuticle. This makes the hair look dull, weak and damaged (Reference: Harris cosmetology, 8th Edition-Edited by Martin M. Rieger: Chapter 1: The substrates-page Nos: 66-68).

Color specialists have always been on the lookout for safer coloring without damaging the hair shaft. Prior art shows work done by using auto oxidisable dyes which colors the hair without the use of peroxides. But all these efforts have been at the risk of longer exposure of dyes to hair as will be explained in the prior art description.

US patent No. 4,529,404 discloses an auto oxidisable hair dye preparation capable of coloring or darkening hair when applied thereto and exposed to the atmosphere. The preparation comprises a mixture of (i) at least one p-phenylene diamine compound, or an acid addition salt thereof (ii) at least one 1,2,4-benzenetriol compound, each compound optionally containing nuclearly substituted Ci-4 alkyl, alkoxy, hydroxyalkyl or halogen.

The above preparation is preferably applied at multiple spaced intervals of time and exposed to the atmosphere until the desired degree of darkening or color build up is attained. The auto oxidisable hair color obtained is natural looking, drab and long wearing.

The drawbacks of the above preparation are the long drawn exposure of dyes on hair, as well as the multiple steps of coloring hair which is a very tedious task. The delivery of color on hair happens only after a long period of time.

US Patent No. 4,054,413 discloses a process for the preparation of the composition defined in the US patent No. 4,529,404.

US patent No. 3,920,384 describes an autoxidisable hair prepartion capable of coloring hair which comprises N,N- bis-(2 hydroxyethyl) p- Phenylene diamine or an acid addition salt thereof and a triol selected from the group consisting of 1,2,4 benzene triol and 1,4,5 trihydroxytoluene.

The above preparation is applied at multiple spaced intervals of time until the desired color build up is obtained.

Similar to the previous reference (US 4529404) this preparation also requires multiple exposure over a long period of time, which is not consumer friendly.

US patent no 5,021,067 discloses a dyeing composition for keratinous fibres and especially for human keratinous fibres which comprises a cosmetically acceptable aqueous medium of:

I. an Indole dye, and

II. a p-Phenylene diamine disubstituted on one of the amino-groups corresponding to the formula:

where R1 and R2 may be identical or different, denote a C1-G, lower alkyl group; C2-C4 lower hydroxyalkyl group; or a C1-C4 alkyl group substituted with an SO3H, or with a mesylamino group or with a carbamyl group substituted or otherwise with one or two C1-C4 alkyl groups, or with a heterocyclic amine, R1 and R2 together with the nitrogen atom to which they are attached, form a 4-6- membered heterocycle ring, especially a piperidino group;

R3, in position 2- or 3, denotes hydrogen or a C1-C4 alkyl, C1-C4 alkoxy or halogen group; as well as their commercially acceptable salts.

The above composition is applied several times successively, and it is found that the tint obtained becomes increasingly dark, this also being known as "progressive dyeing". The application is followed after an exposure of 5-50 minutes, by a rinse, optional shampooing, a further rinse and air drying. After 4 successive applications of this composition on the permanent waved grey hair, the hair has a natural black coloration.

The drawback in this patent is also that of successive application to get desired level of hair darkening. This is again tedious, and a long process where the person has to spend a lot of time in getting hair colored.

In one of our co-pending patent application 2513/CHE/2008 filed on November, 2008, the same deals with a hair dye composition free of oxidizing agents and comprising active ingredients selected from at least one p-phenylene diamine compound or an acid addition salt thereof; 2, 4-diaminophenoxy ethanol of the formula or its salts and substituted benzenes selected from Resorcinol and m-aminophenol.

As regards, our another co-pending patent application 2765/CHE/2010 dt. 22.09.2010, the same deals with a hair colour formulation and a composition/ kit obtained thereof involving active ingredients in combination with a developer/ oxidant comprising (a) at least one ingredient belonging to the class of 1, 4-diamino benzene or its analogs or its salts; (b) at least one ingredient belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its analogs or its salts; (c) at least one ingredient belonging to the class of substituted pyridine derivatives or its analogs or its salts (d) Alkalizer.

Therefore the requirement of the day considering time a premium commodity, is the colour delivery by hair colouring composition/ kit employing ingredients that are safe to use for colouring/ darkening keratinic fibers thereby providing for optimal colour delivery at a faster rate.

Though there are several hair coloring products in the market, they are mostly peroxide developers which are believed to be harsh and damaging to the hair. It has always been desirable to have safe hair coloring products favouring optimal colour delivery on the keratinous fibers at a faster rate thereby generating better consumer acceptance.

Additionally, it is also desirable for the said hair colouring composition involving alkalizer to have better colour delivery and retention in addition to the reduced application time for better consumer acceptance.

Consequently there is a need to provide for alternatives/superior hair colouring composition/ kit that would involve alkalizers and yet be of milder odour and/ or odourless and would also facilitate attainment of optimal colour delivery, ease of application, superior conditioning, premium product appearance, good spreading, uniform application and superior retention of colour.

OBJECTS OF THE INVENTION

It is thus a primary object of the present invention to provide for an auto-oxidisable hair dye composition/kit favouring achievement of optimal colour delivery due to the specific selection of primary intermediates and couplers together with alkalizers free of any developer/ oxidant for effective and also faster colouration of keratinous fibers.

Another object of the present invention is directed to the said auto-oxidisable hair dye composition/kit involving selective alkalizers, primary ingredients and couplers that would superiorly perform by displaying optimum colour delivery due to the use of said selective alkalizer providing for a pH of above 7.5.

Yet another object of the present invention is to provide for the said auto-oxidisable hair dye composition/ kit involving said selective alkalizers for improved retention of hair colour in addition to faster and effective colouration of hair.

Still another object of the present invention is to provide for said improved auto-oxidisable hair dye composition/ kit for hair coloring/ darkening involving selective alkalizers wherein the constituents of which said composition are less harsh on the hair and cost effective in being free of oxidizing agents.

Yet another objective of the present invention is to provide an improved auto-oxidisable hair dye composition/ kit which is easy to apply where no special applicators are required.

Another object of the present invention is directed to auto-oxidisable hair dye composition/kit to be made available in physical forms involving selective alkalizers in selective proportions of actives to define the pH level of the said composition and may be in separate/distinctly identifiable parts and/or as a possible combination for desired user friendly application and use.

Yet a further object of the present invention is directed to the said auto-oxidisable hair dye composition/kit involving selective alkalizers that can be provided in combination with additional hair benefiting agents and/or diffusion agents.

Still another object of the present invention is to provide for the said auto-oxidisable hair dye composition/kit involving selective alkalizers providing for optimal colour delivery in a short span of time and improved colour retention which would thus be beneficial for the skin in having a shorter skin contact time.

SUMMARY OF THE INVENTION

Thus according to the basic aspect of the present invention there is provided an auto-oxidisable hair dye composition/kit suitable for coloring or darkening keratinous fibers comprising:

An auto-oxidisable hair dye composition/kit suitable for coloring or darkening keratinous fibers comprising:

a. at least one ingredient belonging to the class of 1, 4-diamino benzene or its
analogs or its salts;

b. at least one ingredient belonging to the class of substituted pyridine derivatives
or its analogs or its salts;

c. alkalizers adapted to favour optimum colour delivery free of any
developer/oxidant; and

d. optionally, at least one ingredient belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its
analogs or its salts.

It thus the selective finding of the present invention that optimal colour delivery can be attained when the auto-oxidisable hair dye composition/ kit comprising selective primary intermediates and couplers is present together in combination with alkalizers free of any developer/ oxidant.

Importantly thus, by proper selection of the ingredients of the auto oxidisable hair dye composition/ kit of the present invention also involving selective alkalizers , providing a pH of above 7.5, optimal colour delivery was achieved free of developer/ oxidant thereby demonstrating superior efficacy/ performance of the said hair colouring composition/ kit.

In another aspect of the present invention there is provided said auto-oxidisable hair dye composition/ kit wherein said alkalizers (c) comprises atleast one of potash lye, soda lye, monoethanolamine, ammonia & 2-amino-2-methyl-l-propanol providing for a pH of above 7.5, favouring optimum colour delivery.

In another preferred aspect of the present invention there is provided said auto-oxidisable hair dye composition/kit wherein said alkalizers (c) are preferably selected from potash lye, soda lye, monoethanolamine, ammonia and 2-amino-2-methyl-l-propanol adapted to favour optimum colour delivery preferably at the pH levels of 9-12 controlled by the said alkalis free of any developer/oxidant.

In another preferred aspect of the present invention there is provided the said auto-oxidisable hair dye composition/kit wherein said ingredient (a) belonging to the class of 1, 4-diamino benzene or its analogs or its salts are preferably chosen from p-phenylenediamine, N-ethyl-N- (2-hydroxyethyl)-para-phenylenediamine, the
sulphate and hydrochloride,N,N-bis(2-hydroxyethyl)-paraphenylenediamine and
its salts, N-ethyl-N-(2-piperidinoethyl)-para-phenylenediamine and its trihydrochloride, N-ethyl-N- (carbamylmethyl)para-phenylenediamine,
N-ethyl-N-[2-(mesylamino)ethyl]-paraphenylenediamine and its sulphates, and 2-methyl-N,N-dimethyl-para-phenylenediamine and its salts such as the dihydrochloride and is more preferably p-PDA and its salts;

said ingredient (b) belonging to the class of substituted pyridine derivatives or its analogs or its salts is preferably 2-amnio-3-hydroxy pyridine said ingredient;

said alkalizer (c) is provided in cosmetically acceptable form suitable for application on keratinous fibers/hair; and said ingredient (d) belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its analogs or its salts is preferably resorcinol/ p-aminophenol.

In yet another preferred aspect of the present invention there is provided the said auto-oxidisable hair dye composition/kit wherein said ingredient (a) belonging to the class of 1, 4 - diamino benzene or its analogs or its salts, preferably p-PDA and its salts are preferably used in the composition ready for use on hair in proportions of between 0.0 and 10% by weight, more preferably between 0.05 to 0.08% by weight and most preferably between 0.1% to 5% by weight;

said ingredient (b) belonging to the class of substituted pyridine derivatives or its analogs or its salts are preferably used in the composition ready for use on hair in proportions of between 0.01 %-10% by weight, more preferably between 0.05% and 8% and most preferably between 0.1-5% by weight.

said optional ingredient (d) belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its analogs or its salts are preferably used in the composition ready for use on hair in proportions of between 0.01 and 10 % by weight, more preferably between 0.05% and 8% and most preferably between 0.1- 5.% by weight.

In another aspect of the present invention there is provided the said auto-oxidisable hair dye composition/kit comprising diffusion aids including phosphate esters more preferably oleth-5-phosphate and dioleyl phosphate preferably used in the composition ready for use on hair in proportions of between 0.005%-8% by weight, more preferably between 0.05% and 5% and most preferably between 0.1-2% by weight.

In another preferred aspect of the present invention there is provided the said auto-oxidisable hair dye composition/kit comprising effective amounts of the said hair colouring ingredients in association with other hair grooming agents and adjunct ingredients adapted for effective colouring and conditioning of the hair whether it is live as on the head, or dead as in a swatch, wig or hairpiece and instructions providing for directions for use for achieving optimum colour delivery involving said (i) auto oxidisable ingredients in combination with (ii) selective alkalizer providing for selective pH level for optimum colour delivery free of any developer/oxidant.

In yet another preferred aspect of the present invention there is provided for the said auto-oxidisable hair dye composition/kit wherein said composition is in the form of thickened lotion, an unthickened lotion, a gel, an serosol foam, oil pomades, brilliantines, hair tonics, serum and other hair grooming products including said selective alkalizers.

In another aspect of the present invention there is provided a method of colouring the hair involving said hair colouring composition/kit comprising the step of: applying the said hair colouring composition involving alkalizers in a ready to use form for ready application on the hair for colouring/ darkening.

In another preferred aspect of the present invention there is provided the said method of colouring the hair involving the said hair colouring composition/kit comprising the steps of:

a. providing said ingredients of the hair colour composition/ kit;

b. intimately mixing the said auto oxidisable hair dyeing ingredients with the
alkaliser when the alkaliser is provided separately in the kit to provide for a ready to use auto-oxidisable hair colouring composition mix; and

c. applying the said mix on hair for colouring/ darkening it.

The present invention is described hereunder in greater detail in relation to the non-limiting exemplary illustrations.

DETAILED DESCRIPTION OF THE INVENTION

As discussed hereinbefore the present invention provides for an auto-oxidisable hair dye composition/ kit based on alkalizer, free of any developer/ oxidant in combination with specific primary ingredients and couplers to thereby favour optimal colour delivery. Preferably, the involvement of a selective alkalizer provides for a pH of above 7.5 that favours effective colouration of the keratinous fibers with optimum colour delivery on the said fibers. Advantageously, the auto-oxidisable hair dye composition/ kit of the present invention further economizes on time and cost by favouring effective hair coloration by way of superior colour delivery and improved retention of colour even while not incorporating any developer/ oxidant other than the active ingredients in the formulation but instead incorporating selective alkalizers providing for a pH of above 7.5.thereby rendering its safe usage in being free of oxidizing agents. Moreover, the said auto-oxidisable hair dye composition/kit additionally includes other hair benefiting agents and is adapted for use in all cosmetically acceptable forms.

According to an aspect of the present invention there is provided an auto-oxidisable hair dye composition/kit suitable for coloring or darkening keratinous fibers comprising:

a. at least one ingredient belonging to the class of 1, 4-diamino benzene or its analogs or its salts;

b. at least one ingredient belonging to the class of substituted pyridine derivatives
or its analogs or its salts;

c. alkalizers adapted to favour optimum colour delivery free of any
developer/oxidant; and

d. optionally, at least one ingredient belonging to the class of non halogenated
phenols suitably substituted with additional phenolic or amino functionality or its
analogs or its salts.

Suitable alkalizers (c) are preferably selected from potash lye, soda lye, monoethanolamine, ammonia and 2-amino-2-methyl-l-propanol adapted to favour optimum colour delivery at the selective pH level controlled by the said selective alkalis free of any developer/oxidant.

In accordance with yet another aspect of the invention there is provided an auto-oxidisable hair dye composition/kit involving selective alkalizers comprising effective amounts of the said hair colouring ingredients in association with optional hair benefiting ingredients preferably hair conditioning agent.

In yet another aspect of the invention there is provided an auto-oxidisable hair dye composition/kit involving said selective alkalizers in combination with hair grooming or hair benefiting agents whereby the hair, whether it is live as on the head, or dead as in a swatch, wig or hairpiece, is effectively colored and groomed or conditioned.

In accordance with yet another aspect of the invention there is provided an auto-oxidisable hair dye composition/kit involving selective alkalizers comprising of primary intermediates, couplers provided in selective proportions of actives that may be in separate/distinctly identifiable parts and/or as a possible combination.

The said hair dye composition/kit involving selective alkalizers for optimal colour delivery and improved colour retention of the present invention comprises selective combination of primary intermediates and couplers free of developer/ oxidant adapted for colouring hair/ keratinous fibres in a short time.

In a preferred embodiment of the present invention, the auto-oxidisable hair dye composition/ kit is made available in all cosmetically acceptable forms in combination with other hair grooming products and adjunct ingredients, suitable for darkening or colouring of the hair.

The said adjunct ingredients involved in the said hair colouring composition/kit involve well known agents such as plasticizing agents, antioxidant agents, thickening agents, complexing agents, conditioning agents such as cationic polymers and cationic surfactant agents; that may also contain anionic, nonionic or amphoteric surfactant agents as well as silicones, in particular volatile silicones and others.

The above said thickening agent may include higher fatty alcohols, sodium alginate, gum arabic, guar of carob gum, xanthum gum, cellulose derivatives such as methyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose and carboxymethylcellulose and various polymers having thickening functions such as acrylic acid derivatives. It is also possible to use in organic thickeners such as bentonite. The said thickening agents are preferably present in proportions between 0.1 and 30% by weight, more preferably between 0.5% and 20%.

The composition/kit also comprises diffusion aids including phosphate esters more preferably oleth-5-phosphate and dioleyl phosphate are preferably used in the composition ready for use on hair in proportions of between 0.005 %-8% by weight, more preferably between 0.05% and 5% and most preferably between 0.1-2% by weight.

In view of the sensitivity of the hair colouring composition/kit of the present invention to oxidation, the composition is preferably prepared, packaged and stored under anaerobic condition. When packaged as an aerosol under pressure, the hydrocarbon or halohydrocarbon propellants such as butane, propane, LPG, CFC free freons, Liquid Nitrogen, Liquid Carbon di-oxide therein effectively provide for such anaerobic conditions. For non aerosol packagings, premature oxidation of the said composition may be further reduced or eliminated by including antioxidant agents or nitrogen gas or inert gas. Antioxidant agents in sufficient proportions preferably between 0.01% and 5% by weight may be used for protection against oxidation. They are chosen in particular, from sulphites, hydrosulphites, ascorbic acid and Butylated hydroxy toluene.

The said auto-oxidisable hair dye composition/kit involving said selective alkalizers may contain other hair benefiting agents such as UV protection, hair conditioning agents, colour protection, color diffusion agents and the like. Examples of some hair/ colour protection agents such as OMC, Escalol 610HP, Bisquat, dosyquat, Crodafos HCE, Crodafos UV283, Parsol SLX etc are used in sufficient proportions preferably between 0.01 % and 10 % by weight.

The optional ingredient involving colour diffusion agent includes phosphate esters.

The auto-oxidisable hair dye composition/kit of the present invention in the form of cream, lotion and the like involving alkalizers may also be provided in combination with hair grooming or hair conditioning agents whereby the hair, whether it is live as on the head, or dead as in a swatch, wig or hairpiece, is simultaneously colored and groomed or conditioned.

The details of the invention are given in the following exemplary illustrations and therefore should not be construed to limit the scope of the invention.

The composition of the present invention is generally prepared by the process described below.

The composition of the present invention is generally prepared the process described below.

Cetostearyl and lauryl alcohol are heated to a temperature of 75 deg C. Sodium lauryl ether and water are added to the mixture and agitated for 5 minutes. Cooled to 55 deg C, added the cationic polymer Polyquaternium 10 and agitated for a further period of 5 minutes. Cooled to 45 deg C,added Sodium sulphite to it and agitated again for 5 minutes. The dye intermediates p-PDA, p-aminophenol, Resorcinol, 2-amino-3-hydroxy pyridine dissolved in propylene glycol are then added and agitated for 10 minutes and cooled to 30 deg C.

The following examples are intended to explain the invention in further detail in terms of some definite ratios of dye intermediates in combination with modulating pH levels of said selective alkalizers, to thereby illustrate the superior efficacy of a particular selective alkalizer at that defined pH level present in combination with said dye intermediates without limiting it to these examples.

It is thus possible by way of the present invention to provide for the desired auto-oxidisable hair dye composition/kit involving selective alkalizers based combination with specific primary ingredients and couplers free of any developer/ oxidant resulting in optimal colour delivery, when said selective alkalizers are present providing a pH of above 7.5.

More specifically, the present invention is directed to serve the much desired need for safe and faster hair colouration thus attained due to the right choice of the alkalizers when present at their said defined pH levels in combination with specific primary intermediates and couplers results in optimal colour delivery even in the absence of developer/ oxidants, which is thus safe to apply, economical with regard to the time and cost involved in the hair colouring process with better consumer acceptance. Importantly, the present invention thus favours in obtaining the said hair colouring composition/kit in all cosmetically forms in combination with a cosmetically/ acceptable vehicle containing other hair benefiting agents. Advantageously also, the hair colouring composition of the present invention delivers excellent dye deposition, delivers color uniformly which is maintained over consumers wash cycle and importantly is safe to use in being free of oxidizing agents.

We Claim:

1. An auto-oxidisable hair dye composition/kit suitable for coloring or darkening
keratinous fibers comprising:

a. at least one ingredient belonging to the class of 1, 4-diamino benzene or its analogs or its salts;

b. at least one ingredient belonging to the class of substituted pyridine derivatives
or its analogs or its salts;

c. alkalizers adapted to favour optimum colour delivery free of any
developer/oxidant; and

d. optionally, at least one ingredient belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its
analogs or its salts.

2. An auto-oxidisable hair dye composition/ kit as claimed in claim 1 wherein
said alkalizers (c) comprises atleast one of potash lye, soda lye, monoethanolamine,ammonia & 2-amino-2-methyl-l-propanol providing for a pH of above 7.5, favouring optimum colour delivery.

3. An auto-oxidisable hair dye composition/kit as claimed in claims 1 or 2 wherein said alkalizers (c) are preferably selected from potash lye, soda lye, monoethanolamine, ammonia and 2-amino-2-methyl-l-propanol adapted to favour optimum colour delivery preferably at the pH levels of 9-12 controlled by the said alkalis free of any developer/oxidant.

4. An auto-oxidisable hair dye composition/kit as claimed in any of the preceding claims wherein said ingredient (a) belonging to the class of 1, 4-diamino benzene or its analogs or its salts are preferably chosen from p-phenylenediamine, N-ethyl-N- (2-hydroxyethyl)-para-phenylenediamine, the sulphate and hydrochloride,N-bis(2-hydroxyethyl)-paraphenylenediamine and its salts, N-ethyl-N-(2-piperidinoethyl)-para-phenylenediamine and its trihydrochloride, N-ethyl-N-(carbamylmethyl)para-phenylenediamine, N-ethyl-N-[2-(mesylamino)ethyl]-paraphenylenediamine and its sulphates, and 2-methyl-N,N-dimethyl-para-phenylenediamine and its salts such as the dihydrochloride and is more preferably p-PDA and its salts ;

said ingredient (b) belonging to the class of substituted pyridine derivatives or its
analogs or its salts is preferably 2-amnio-3-hydroxy pyridine;

said alkalizer (c) is provided in cosmetically acceptable form suitable for application
on keratinous fibers/hair; and

said ingredient (d) belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its analogs or its salts is preferably resorcinol/ p-aminophenol.

5. An auto-oxidisable hair dye composition/kit as claimed in any of the preceding claims wherein said ingredient (a) belonging to the class of 1, 4 - diamino benzene or its analogs or its salts, preferably p-PDA and its salts are preferably used in the composition ready for use on hair in proportions of between 0.01 and 10% by weight, more preferably between 0.05 to 8% by weight and most preferably between 0.1% to 5% by weight;

said ingredient (b) belonging to the class of substituted pyridine derivatives or its analogs or its salts are preferably used in the composition ready for use on hair in proportions of between 0.01 %-10% by weight, more preferably between 0.05% and 8.% and most preferably between 0.1-5% by weight.

said optional ingredient (d) belonging to the class of non halogenated phenols suitably substituted with additional phenolic or amino functionality or its analogs or its salts are preferably used in the composition ready for use on hair in proportions of between 0.01 and 10 % by weight, more preferably between 0.05% and 8% and most preferably between 0.1-5% by weight.

6. An auto-oxidisable hair dye composition/kit as claimed in any of the preceding claims comprises diffusion aids including phosphate esters more preferably oleth-5-phosphate and dioleyl phosphate preferably used in the composition ready for use on hair in proportions of between 0.005 %-8% by weight, more preferably between 0.05% and 5% and most preferably between 0.1 - 2% by weight.

7. An auto-oxidisable hair dye composition/kit as claimed in any of the preceding claims comprising effective amounts of the said hair colouring ingredients in association with other hair grooming agents and adjunct ingredients adapted for effective colouring and conditioning of the hair whether it is live as on the head, or dead as in a swatch, wig or hairpiece and instructions providing for directions for use for achieving optimum colour delivery involving said (i) auto oxidisable ingredients in combination with (ii) selective alkalizer providing for a pH of above 7.5 for optimum colour delivery free of any developer/oxidant.

8. An auto-oxidisable hair dye composition/kit as claimed in any of the preceding claims wherein said composition is in the form of thickened lotion, an unthickened lotion, a gel, an serosol foam, oil pomades, brilliantines, hair tonics, serum, spray, mousse, powder and other hair grooming products including said selective alkalizers.

9. A method of colouring the hair involving hair colouring composition/kit as claimed in anyone of the preceding claims comprising the step of:

applying the said hair colouring composition involving alkalizers in a ready to use form for ready application on the hair for colouring/ darkening.

10. A method of colouring the hair involving hair colouring composition/kit as
claimed in anyone of the preceding claims comprising the steps of:

a. providing said ingredients of the hair colour composition/ kit;

b. intimately mixing the said auto oxidisable hair dyeing ingredients with the alkaliser ,when the alkaliser is provided separately in the kit, to provide for a ready to use auto-oxidisable hair colouring composition mix; and

c. applying the said mix on hair for colouring/ darkening it.

11.An auto-oxidisable hair dye composition/kit involving alkalizers favouring optimal colour delivery free of any developer/ oxidant and its process of manufacture and method of colouring the hair involving the said hair colouring composition/ kit substantially as herein described and illustrated with reference to the accompanying examples.