Methods and compositions for coloring keratin substrates using solubilized vat dyes

Abstract

The present disclosure relates to methods for coloring keratin substrates using solubilized vat dyes, as well as compositions and kits suitable for carrying out the methods. The present disclosure also relates to novel solubilized vat dyes.

Description

[Background technology]

[0001] Treatments for mammalian or synthetic keratin fibers are known. Mammalian keratin fibers (natural hair) are structured as a cuticle or outer surface layer, a cortex, which is an inner middle layer containing melanin or pigment bodies and keratin bundles, and a central core called the medulla. Typical dye treatments focus on altering the hair cortex. Of particular note are hair cortex treatments that change the appearance of the hair, for example, by changing its color or reflective properties. This can be achieved by treating the cortex with a formulation containing dye molecules that diffuse into or are absorbed through the cuticle of the hair fiber (so-called direct dyes).

[0002] Alternatively, so-called oxidation dyes can be used, in which dye precursors (intermediates called primers and couplers) diffuse into the cortex and then react to form colored species within the hair cortex. Oxidation dye products are often designed to lift hair and bleach some of the melanin in the cortex, allowing for a broader color range. Over time, the color imparted to hair is removed with washing. This can be accomplished quickly with so-called direct dyes, resulting in a short-term change in hair appearance that typically lasts for a few washes. So-called oxidation dyes can last much longer, and indeed, can be difficult to remove, even after numerous washes. When the oxidation dye is finally washed off and removed, it does not revert to its original color, but to a lighter color, because the melanin has also been bleached by the bleach. Unfortunately, the process of bleaching hair by intentionally applied bleaching techniques not only lifts the hair, but also leads to a change in the perceived hair tone, often described as an off-tone or "brassy" result where the hair appears more orange than untreated hair of a similar lightness.

[0003] Another method of hair coloration is to deposit pigments onto the hair surface to alter the perceived color, but this approach typically only lasts until the next time the hair is washed.

[0004] One drawback of known oxidation-based techniques in this field is that color durability is significantly reduced when a second lift (e.g., bleaching) is applied. Even under mildly oxidizing conditions at a moderate alkaline pH (e.g., pH=9.0), the durability of various shades is not consistent, meaning that fashionable red shades are always more prone to washing out at a higher rate than darker, natural shades.

[0005] Another drawback of traditional oxidative colorants is their inability to produce a wide range of vibrant shades across all areas that are completely consistent and long-lasting.

[0006] Another challenge that remains to be solved is the presence of several significant "white zones" in areas that cannot be filled by standard oxidative hair colorants. For example, fashionable orange hues cannot be achieved directly using oxidative coupling agents, and therefore these color spaces must be bridged with direct dyes, which are significantly less durable than oxidative coloring, leading to an inconsistent color experience until the customer intentionally refreshes their hair color.

[0007] Another significant drawback of oxidative colorants becomes apparent when higher lift standards are applied to completely bleach natural melanin to obtain blonde / bleached hair, while simultaneously applying a new color that is resistant to more severe oxidative conditions. Such a procedure is simply not achievable with oxidative colorants that use primaries and couplers of any origin. Today, selected direct dyes, primarily anionic dyes, have been found to be resistant to bleaching conditions, as described by Said et al. (U.S. Pat. No. 7,189,265 B2). While this was rightly considered a groundbreaking discovery, a major drawback regarding durability remains unresolved. This unresolved durability is particularly disadvantageous when, for example, the blue dyes (e.g., tetrabromophenol blue) described in U.S. Pat. No. 7,189,265 B2, which are resistant to bleaching conditions, are also used to enhance the brassy blonde shade after bleaching virgin hair to achieve an attractive cosmetic result as an attractive blonde shade. However, blue direct dyes quickly fade within one to three washes, and the brassy blonde effect reappears.

[0008] A drawback of alternative coloring concepts using pigments is the low adhesion fastness of the pigments or coloring materials to keratin fibers.

[0009] Therefore, there is a need for hair coloring compositions and methods that address the aforementioned shortcomings of known techniques. The present invention addresses this need by providing methods, compositions, and kits for coloring keratin substrates that avoid the shortcomings of oxidative hair coloring techniques, provide long-lasting coloration, and allow for a wide range of colors, including shades and hues unattainable by oxidative hair dyeing techniques. In addition, the methods of the present invention allow for simultaneous hair lift over a full range, covering mild oxidative lift to harsh bleaching conditions.

[0010] The concept of using solubilized vat dyes according to the present invention, particularly those from the broader family of indanthrene dyes (e.g., those featuring anthraquinone, acridine, perylene, naphthalene, and violanthrone backbones), represents a unique, novel, and versatile stand-alone oxidation hair dyeing technology that enables a full professional color palette of shades without the use of any of the common oxidizing components, such as primers and couplers. Hair coloring using these solubilized vat dyes exhibits ultra-durable durability with exceptional wash and lightfastness properties across any commonly known oxidation stage, from mild oxidation conditions with hydrogen peroxide levels of <2.0% to bleach conditions using hydrogen peroxide levels of 12.0%, even when combined with persulfates. This concept, for the first time, allows complete flexibility and artistic freedom to create any possible shade (natural and very light fashion shades) using an unlimited range of oxidation / lift levels using the same set of dye compounds.

[0011] U.S. Pat. No. 5,364,415 A (Lewis et al.) discloses a hair coloring method based on a mild oxidative hair coloring system containing primary intermediates and couplers, which contemplates additional application of one of seven selected solubilized vat dyes as a color-brightening specialty ingredient to the hair to obtain brighter red and yellow colors than can be obtained with typical oxidative colorants alone.

[0012] German Patent Application Publication No. 102004014764A1 (Javet et al.) discloses a hair colorant comprising a vat dye and a reducing agent that forms enediol under alkaline conditions, which converts the vat dye to the leuco form under alkaline conditions. The reference discloses stabilization of the leuco form by appropriate packaging, a protective gas blanket, the addition of stabilizing and / or protective substances (e.g., polymers, surfactants, cationic compounds such as metal ions), or esterification. German Patent Application Publication No. 102004014763A1 (Javet et al.) discloses a similar hair colorant in which the vat dye is an indigoid vat dye and the composition further comprises a cationic compound, again comprising a reducing agent that forms enediol under alkaline conditions.

[0013] U.S. Patent Application Publication No. 2003 / 0074745A1 (Vainshalboim et al.) discloses a method and system for dyeing hair without the use of chemical oxidizing agents, in which the dyes used are solubilized indigoid and anthraquinone vat dyes.

[0014] U.S. Patent Application Publication No. 2011 / 0189116A1 (Gauche et al.) discloses a method for coloring a material that includes applying a sulfur-containing nucleophile to the material; and applying a composition that includes a dye compound other than a reactive dye to the material. Summary of the Invention

[0015] This invention discloses a novel, highly versatile oxidative hair coloring system that addresses most of the current problems associated with oxidative hair coloring. Furthermore, we describe a set of specialized solubilized vat dyes that can be easily applied to hair by professional users, such as hair stylists, while exhibiting absolutely comparable properties in terms of light and wash fastness, a unique and novel experience among the current state of commercial oxidative dyes. These dyes are also commonly and commercially used for dyeing delicate fabrics, such as silk. The invention utilizes leuco vat dye sulfates, which are obtained from leuco vat dye pigments by reduction in an alkaline medium to obtain the leuco form, followed by treatment with chlorosulfonic acid or simply sulfur trioxide. Leuco vat dye sulfates and their preparation are disclosed, for example, in German Patent No. 1117242B. Leuco vat sulfates can be rapidly cleaved to form the classical leuco forms of the corresponding vat dyes. Subsequent oxidation precipitates the insoluble vat dyes as pigments. The terms "solubilized vat dye," "leuco vat dye sulfate," and "sulfate ester of vat dye" are used interchangeably in this disclosure.

[0016] According to a first aspect, the present invention provides a method for coloring a keratinous substrate. The method comprises applying a first composition (also referred to herein as Composition A) to the keratinous substrate, the composition comprising an aqueous medium and a solubilized vat dye dissolved in the medium. The solubilized vat dye is a leuco vat dye sulfate ester. The first composition is essentially free of an oxidation dye precursor selected from primary intermediates and couplers. According to one embodiment, the first composition is free of an oxidation dye precursor selected from primary intermediates and couplers. The method further comprises applying a second composition (also referred to herein as Composition B) to the keratinous substrate. The second composition has a pH in the range of 3.0 to 5.0. The method optionally further comprises applying a third composition (also referred to herein as Composition C) to the keratinous substrate, the composition comprising an oxidizing agent.

[0017] According to a second aspect, the present invention provides a method for correcting the brassy tint or hue of hair. The method is particularly suitable for correcting the brassy tint or hue of lifted mammalian hair, such as human hair (scalp with hair). The method comprises applying a first composition (also referred to herein as Composition AA) to hair, the composition comprising an aqueous medium and a solubilized vat dye dissolved in the medium. The solubilized vat dye is a leuco vat dye sulfate. The leuco vat dye sulfate present in the first composition is derived from a vat dye that imparts an overall blue or bluish color. The first composition is essentially free of oxidation dye precursors selected from primary intermediates and couplers. According to one embodiment, the first composition is free of oxidation dye precursors selected from primary intermediates and couplers. The method further comprises applying a second composition (also referred to herein as Composition BB) to hair. The second composition has a pH in the range of 3.0 to 5.0. The method optionally further comprises applying a third composition (also referred to herein as composition CC) to the hair, the composition comprising an oxidizing agent.

[0018] According to a third aspect, the present invention provides a method for altering the color of a keratinous substrate colored with a vat dye. The method is suitable for altering the color of a keratinous substrate previously colored by a method according to the present invention for coloring a keratinous substrate. The method is also suitable for altering the color of mammalian hair whose color or hue has previously been corrected by a method according to the present invention for correcting a brassy color or hue in lifted mammalian hair. The correction method comprises applying to the keratinous substrate a fourth composition (also referred to herein as Composition D) having a pH in the range of 11.0 to 12.0. Composition D further comprises a reducing agent.

[0019] According to a fourth aspect, the present invention provides a composition for coloring keratinous substrates. The composition corresponds to the first composition (composition A or AA) of the method of the present invention. The composition comprises an aqueous medium and a solubilized vat dye dissolved in the medium, the solubilized vat dye being a leuco vat dye sulfate ester. The composition is essentially free of oxidation dye precursors selected from primary intermediates and couplers. According to one embodiment, the composition is free of oxidation dye precursors selected from primary intermediates and couplers.

[0020] According to a fifth aspect, the present invention provides a kit for coloring keratinous substrates. The kit comprises a first compartment (also referred to herein as compartment A) containing a leuco vat dye sulfate ester or a salt thereof. The kit further comprises a second compartment (also referred to herein as compartment B) containing an acid or a salt thereof. According to embodiments, the kit may further comprise one or more additional compartments containing ingredients useful in the methods of the present invention.

[0021] According to a sixth aspect, the present invention provides a novel leuco vat dye sulfate ester or a salt thereof. In particular, the present invention provides the following leuco vat dye sulfate ester or a salt thereof: Solubilized Pigment Violet 19 according to formula (I), Solubilized Pigment Red 122 according to formula (II), Solubilized Pigment Red 194 according to formula (III), Solubilized Pigment Orange 43 according to formula (IV), Solubilized tetraazaviolanthrone-trans-black according to formula (V), Solubilized tetraazaviolanthrone-cis-black according to formula (VI), Solubilized perylene-amidine-trans-blue according to formula (VII), Solubilized perylene-amidine-cis-blue according to formula (VIII), solubilized naphthalene-amidine-trans-blue according to formula (IX), and Solubilized naphthalene-amidine-cis-blue according to formula (X):

[0022] Formulas (I) through (X) are set forth in the detailed description.

[0023] According to a seventh aspect, the present invention provides the use of a leuco vat dye sulfate as defined above in a vat dyeing process, in particular for colouring keratinous substrates.

[0024] According to an eighth aspect, the present invention provides a substrate, in particular a fibrous substrate, having adsorbed thereon the novel leuco vat dye sulfate according to the present invention.

[0025] The vat dyes used in accordance with the teachings of this invention are not susceptible to oxidative degradation and can therefore be applied across all oxidation levels without any limitations to the user. Therefore, these vat dyes can be applied under mildly oxidative conditions with just moderate to low lift on virgin hair, and equally applicable under more severe conditions such as bleaching without loss of durability, thus introducing for the first time a comprehensive and universal solution without any compromises in the field of oxidation dyeing. The coloring process takes an average of no more than one hour, comparable to most standard oxidation hair colorings. It involves: 1) a penetration step into swollen hair under mildly alkaline conditions (approximately pH = 9.0); 2) a short reaction step initiated by lowering the pH to slightly acidic conditions (approximately pH = 3.5) where the sulfate ester groups are hydrolyzed; followed by 3) a controlled deposition (oxidation) step of the corresponding vat dye as an insoluble vat pigment in the cortex under alkaline conditions (pH range 9.0-11.0) by a bleaching agent such as atmospheric oxygen, peroxide, or persulfate. [Brief explanation of the drawings]

[0026] 1-5 show hair tresses that have been colored in accordance with the present disclosure by application of the indicated solubilized vat dye, hydrolysis of the ester, and oxidation under the conditions indicated.

[0027] [Figure 1] Figure 1 shows a natural blonde human hair tress treated with oxidizing conditions containing solubilized Bat Violet 1C.I. 60011, CAS 1324-57-8 (100 mg in 10 mL solvent; 1 wt%); 9% hydrogen peroxide, pH = 9.0.

[0028] [Figure 2] FIG. 2 shows natural blonde human hair tresses treated with solubilized Vat Yellow 4 C.I. 59101, CAS 3564-70-3 (100 mg in 10 mL solvent; 1 wt %); oxidizing conditions including 12% hydrogen peroxide, and Blonder powder (a bleaching powder containing peroxodisulfate, a commercial brand from Wella).

[0029] [Figure 3] FIG. 3 shows a natural blonde human hair tress treated with oxidizing conditions including solubilized Bat Yellow 4 C.I. 59101, CAS 3564-70-3 (100 mg in 10 mL solvent; 1 wt %); 9% hydrogen peroxide, pH=9.0.

[0030] [Figure 4] FIG. 4 shows natural dark brown (5 / 0) human hair tresses treated with solubilized Bat Green 1 C.I. 59826, CAS 2538-84-3 (100 mg in 10 mL solvent; 1 wt %); oxidizing conditions including 12% hydrogen peroxide, and Blonder powder (a bleaching powder containing peroxodisulfate, a commercial brand from Wella).

[0031] [Figure 5] FIG. 5 shows natural dark brown (5 / 0) human hair tresses treated with solubilized Vat Violet 1 and solubilized Vat Green 4 (1:1) (50 mg each in 10 mL of solvent; 1% dye content by weight); oxidizing conditions including 12% hydrogen peroxide; and Blonder powder (a bleaching powder containing peroxodisulfate, a commercial brand from Wella).

[0032] [Figure 6] The top panel of Figure 6 shows a natural dark brown (5 / 0) human hair tress treated with solubilized Vat Blue 4 (10 mg in 10 mL of solvent, 0.1 wt% dye content); oxidizing conditions including 12% hydrogen peroxide; and Blonder powder (a bleaching powder containing peroxodisulfate, a commercial brand from Wella).

[0033] The bottom of Figure 6 shows a natural dark brown (5 / 0) human hair tress treated with oxidizing conditions including 12% hydrogen peroxide and Blonder powder (a bleaching powder containing peroxodisulfate, a commercial brand from Wella) (without dye addition as a reference to show the brassy blonde effect).

[0034] [Figure 7] Figure 7 shows a tress of natural blonde human hair treated with solubilized Vat Green 1 and solubilized Vat Yellow 4 (2:1); oxidizing conditions including 9% hydrogen peroxide; and Blonder powder (a bleaching powder containing peroxodisulfate, a commercial brand of Wella). The top panel of Figure 7 shows the tress immediately after coloring ("Fresh ON"), and the bottom panel of Figure 7 shows the color persistence of the same colored tress after 15 washes with shampoo.

[0035] [Figure 8] Figure 8 shows a natural blonde human hair tress treated with oxidizing conditions including solubilized Vat Green 1 and solubilized Vat Yellow 4 (1:1); 9% hydrogen peroxide. The top of Figure 8 shows the tress immediately after coloring ("Fresh ON"), and the bottom of Figure 8 shows the color persistence of the same colored tress after 15 washes with shampoo.

[0036] [Figure 9] Figure 9 shows two pairs of tresses of natural blonde human hair treated with solubilized Bat Yellow 4 (1:1); oxidation conditions containing 9% or 12% hydrogen peroxide, respectively; Blonder powder = bleaching powder containing peroxodisulfate, a commercial brand from Wella. The top pair shows the coloration after oxidation with 12% hydrogen peroxide, the upper tress obtained immediately after coloring ("Fresh ON"), the lower tress after 15 washes with shampoo. The bottom pair shows the coloration after oxidation with 9% hydrogen peroxide, the upper tress again obtained "Fresh ON", the lower tress after 15 washes with shampoo.

[0037] [Figure 10]Figure 10 shows two pairs of tresses of natural blonde human hair treated with oxidizing conditions containing solubilized Bat Yellow 4; 9% or 6% hydrogen peroxide, respectively. The top pair shows the color after oxidation with 9% hydrogen peroxide, the top tress obtained "Fresh ON", and the bottom tress after 15 washes with shampoo. The bottom pair shows the color after oxidation with 6% hydrogen peroxide, the top tress again obtained "Fresh ON", and the bottom tress after 15 washes with shampoo.

[0038] [Figure 11] Figure 11a shows a comparison of the coloration obtained using Vat Yellow 4 or the commercial shade Magma Limoncello, respectively, in a salon test immediately after coloring ("Fresh ON"), and Figure 11b shows a comparison of the coloration obtained using Vat Yellow 4 or the commercial shade Vidal Sassoon Yellow, respectively, in a salon test immediately after coloring ("Fresh ON").

[0039] [Figure 12] Figure 12a shows a comparison of the color obtained using Vat Yellow 4 or the commercial shade Magma Limoncello in a salon test after 5 washes with shampoo, and Figure 12b shows a comparison of the color obtained using Vat Yellow 4 or the commercial shade Vidal Sassoon Yellow in a salon test after 5 washes with shampoo.

[0040] [Figure 13] Figure 13a shows a comparison of the color obtained using Vat Yellow 4 or the commercial shade Magma Limoncello in a salon test after 10 washes with shampoo, and Figure 13b shows a comparison of the color obtained using Vat Yellow 4 or the commercial shade Vidal Sassoon Yellow in a salon test after 10 washes with shampoo.

[0041] [Definition] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0042] The term "may" in the context of this application means "allowable" or "possible," and is synonymous with the term "can." As used herein, the term "may" does not imply possibility or likelihood.

[0043] The term "and / or" in the context of this application means one or the other or both. For example, an aqueous solution of A and / or B means an aqueous solution of A alone, an aqueous solution of B alone, and an aqueous solution of A and B in combination.

[0044] The term "about" is understood to mean ±10 percent of the stated number, number, or range of numbers. In some embodiments, the term "about" is understood to mean ±2 percent of the recited number, numbers, or range of numbers.

[0045] The term "about 0% by weight" is understood to mean that the substance, compound, or material referred to by zero (0) is not present, but is present in negligible but detectable amounts, assuming detectability on a ppm (parts per million) basis.

[0046] When features or aspects of the invention are described in terms of a Markush group, one of ordinary skill in the art will recognize that the invention is also described thereby with respect to any individual member or subgroup of members of the Markush group. For example, if X is recited as being selected from the group consisting of methyl, ethyl, or propyl, a claim in which X is methyl and a claim in which X is methyl and ethyl are both fully described. Furthermore, when features or aspects of the invention are described in terms of a Markush group, one of ordinary skill in the art will recognize that the invention is also described thereby with respect to any combination of individual members or subgroups of members of the Markush group. Thus, for example, if X is recited as being selected from the group consisting of bromine, chlorine, and iodine, and Y is recited as being selected from the group consisting of methyl, ethyl, and propyl, a claim in which X is bromine and Y is methyl is also fully described.

[0047] When the value of a variable that is necessarily an integer, such as the number of carbon atoms in an alkyl group or the number of substituents on a ring, is recited as a range, e.g., 0 to 4, what is meant is that the value can be any integer between 0 and 4 (inclusive), i.e., 0, 1, 2, 3, or 4. Similarly, values ​​expressed in range format should be interpreted in a flexible manner to include not only the numerical values ​​explicitly recited as the limits of the range, but also all individual numerical values ​​or subranges subsumed within that range, as if each numerical value and subrange were explicitly recited. For example, the range "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted to include not only about 0.1% to about 5%, but also individual values ​​(e.g., 1%, 2%, 3%, and 4%) and subranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the recited range.

[0048] The term "keratin substrate" as used herein refers to any natural or synthetic substrate made from or containing keratin. In particular, the term "keratin substrate" encompasses natural and synthetic keratin fibers. Preferred keratin substrates are natural keratin fibers. Natural keratin fibers include fibers of and / or on mammals, including, but not limited to, cattle, sheep, deer, goats, buffalo, llama, alpaca, camel, guanaco, vicuna, horse, antelope, moose, elk, rat, mouse, beaver, rabbit, mink, monkey, ape, and similar species, including humans, primates, ruminants, camelids, equines, rodents, and neobison. Natural keratin fibers may include hair, fur, or nails. Particularly preferred keratin substrates in the present disclosure are mammalian keratin fibers, particularly human scalp hair (haired scalp). The term "keratinous fibers" is used interchangeably in this specification with the terms "hair" or "hair strands", unless the context otherwise defines.

[0049] As used herein, "optionally" means that the corresponding substituent or entity may or may not be present. Both possibilities are included.

[0050] The term "water-soluble" as used herein refers to a solubility in an aqueous medium at 25°C of a composition for treating keratinous substrates of at least 1.0% by weight, in particular at least 5.0% by weight, for example at least 10.0% by weight, such as at least 25.0% by weight.

[0051] As used herein, the term "composition" refers to a mixture or blend containing at least two components. A typical composition includes at least one functional component (e.g., a leuco vat dye sulfate, a pH adjuster, an oxidizing or reducing agent, etc.) and at least one solvent component (e.g., water or alcohol). The composition may exist in any suitable physical form, including, for example, liquids of various viscosities, gels, foams, creams, etc. The term "composition" typically refers to a ready-to-use composition, unless the context otherwise defines it. "Ready-to-use" refers to a form in which the composition is actually applied to a keratinous substrate, such as mammalian hair, particularly human scalp hair.

[0052] The term "alkalinizing agent" as used herein refers to any compound suitable for adjusting the pH of a composition to the alkaline range. Typical alkalinizing agents include bases such as NaOH, ammonia, urea, pyridine, aminomethylpropanol (AMP), monoethanolamine, and DBU (diazabicyclo-undecane). Pyridine and DBU may pose safety issues and are therefore less preferred.

[0053] The term "essentially free" of a particular component means that the respective component is present in an entity, such as a composition, in an amount of less than 1.0% by weight, based on the total weight of the entity. In particular, the term "essentially free" means that the respective component is present in an entity in an amount of less than 0.5% by weight, e.g., less than 0.1% by weight, e.g., 0.01% by weight. The term "free" of a particular component means an amount below the detection limit, assuming detectability on a ppm (parts per million) basis. DETAILED DESCRIPTION OF THE INVENTION

[0054] 1 Solubilized vat dye Vat dyes are known and have been used for decades as powerful dyes and pigments for dyeing fabrics. In particular, those of the indanthrene family exhibit excellent properties in terms of lightfastness, washfastness, are stable against all oxidative events, and are extremely weather-resistant. In addition, they exhibit a pronounced melting point above 100°C, indicating high chemical stability. The only option for chemically modifying them is to apply a reduction process to convert them into a soluble and therefore processable form. The soluble form of vat dyes is also known as the "leuco" form. A typical scheme of the conversion option is shown in Scheme 1.

[0055] Scheme 1: JPEG0007759936000001.jpg42168

[0056] Harsh alkaline conditions are typically required to reduce vat dyes (the right formula in Scheme 1) to their corresponding leuco forms (the center formula in Scheme 1), which are soluble in their leuco form and can be applied as solutions and penetrate into keratin fibers as soluble dyes. However, such harsh conditions (pH > 13.0) cannot be applied to delicate (sensitive) keratin fibers or living organisms. Vat dye leuco sulfate esters (the left formula in Scheme 1) represent reactive, readily soluble forms of vat dye pigments. They can be used under very mild conditions, making them suitable for coloring sensitive substrates (e.g., natural fibers) or living substrates, thereby avoiding the harsh conditions required for leuco vat dyes.

[0057] Leuco vat dye sulfates are perfect candidates because this structural element opens the door to many chromophores that can be so modified. An ideal chromophore candidate should possess at least two carbonyl groups, combined with an extended aromatic π-system, to which reduction and oxidation steps can be applied according to the scheme above. These solubilized sulfate vat dyes exhibit the entirely unexpected ability to penetrate deep into the hair cortex under mildly alkaline conditions (pH = 9.0), optionally in the presence of a swelling promoter such as urea or ammonia. This finding is not obvious given the size and bulky structure of the chromophore.

[0058] Other bulky dyes known in the literature, such as direct dyes (e.g., azo dyes, anthraquinone dyes, etc.) with anionic or cationic charge, are also observed to have very moderate to low penetration into the hair cortex. Therefore, these traditional direct dyes only adsorb to the outer surface of the hair, as can be seen by microscopic observation of a cross-section of the hair. Therefore, the penetration properties of solubilized vat dyes are remarkable, resulting in the outstanding durability of the color achieved compared to other chromophores such as the direct dyes mentioned above.

[0059] After the alkaline penetration step is complete, reducing the pH to a moderately acidic condition (pH = 3.5) forces hydrolysis of the unstable sulfate ester groups to yield the pure, reduced leuco form, which is then rapidly oxidized in the presence of atmospheric oxygen, hydrogen peroxide, and / or bleaching ingredients such as persulfates. After reoxidation is complete, the vat dye pigments are deposited in the hair cortex, achieving exceptionally long-lasting hair coloration. This is due to the extremely low solubility of the formed pigment in an aqueous environment. This type of coloration therefore provides extremely long-lasting coloration with exceptional washfastness. After more than 15 shampoo washes, the treated hair remains completely unchanged, with the entire color load still remaining, with no trace of color loss.

[0060] However, hair coloring has attracted the attention of toxicologists, and before compounds can be used in commercial hair coloring formulations, they must receive safety approval from authorities. Therefore, it is necessary to select appropriate chromophore structures to provide vat dyes that can be used commercially. Unlike the prior art in U.S. Pat. No. 5,364,415 (Lewis et al.), which does not provide a selection of commercially available solubilized vat dyes, the intent of this disclosure is to propose a variety of specialized vat dyes that have a high probability of meeting all the criteria for toxicological prerequisites. The most important issue is whether these dyes have the ability to penetrate the skin. Most of the dyes previously published for hair coloring, regardless of whether they are applied under non-oxidizing or oxidizing conditions, have shown a significant tendency to penetrate the skin, simply due to their water solubility as hydrophilic, anionic, or cationic dyes, which is a prerequisite for their processing onto hair fibers. Therefore, obtaining safety approval from authorities requires sophisticated and costly toxicological evaluation. The key improvement over the prior art is primarily the elimination of skin penetration. It is common knowledge that pigments such as the final precipitated vat dyes are completely insoluble and not bioavailable, and therefore not of interest for further toxicological evaluation. Therefore, the focus here is clearly on solubilized vat dyes as intermediate forms that are applied to hair fibers to enable penetration into the hair cortex. Therefore, according to the present invention, a chromophore with a large, extended electron π system is preferably contemplated to obtain an acceptable safety assessment. This excludes all indigoid vat dyes, as their molecular weights are considered too low and they are likely to easily penetrate the skin. On the other hand, the aforementioned vat dyes and solubilized vat dyes each exhibit high molecular weights, and the chromophore design is characterized by a uniform, extended, bulky aromatic polycyclic hydrocarbon surface. This bulky structure exhibits significant hydrophobicity and steric hindrance, significantly reducing the likelihood of skin penetration. This is emphasized by the relatively moderate LogP values ​​of the solubilized vat dyes (see Scheme 2: Selection of solubilized vat dye LogP values), which exhibit a significantly low hydrophilicity, providing exceptionally good water solubility (see LogWS values) caused by a minimum of two sulfate ester groups.

[0061] Scheme 2: JPEG0007759936000002.jpg95168

[0062] Another issue regarding the toxicological evaluation of solubilized vat dyes compared to other widely used oxidative hair coloring intermediates is the fact that a selection of solubilized vat dyes, without exception, lack aromatic amine functionality. Since most traditional oxidative hair colorants are aromatic amines, this poses significant consumer health concerns. Indeed, the absence of aromatic amine functionality, combined with the expected low skin penetration capacity due to the chromophore design, is a clear advantage over oxidative colorants known from the prior art.

[0063] The resulting hair color is extremely durable—a wonderful and unique finding—but professional hair products must also demonstrate the ability to be adjusted in case something goes wrong during the coloring service or the customer is dissatisfied with the intended color result. Traditional oxidative hair colorants, which use primers and couplers to create color molecules, can be adjusted or corrected as needed within predetermined boundaries. This is done through bleaching, which decomposes the chromophore, since standard oxidative hair pigments are not stable to bleaching conditions. Obviously, this concept doesn't work with vat dyes, which, as already mentioned, exhibit remarkable stability against the oxidative processes commonly performed on human hair. The only option here is to convert the vat dye pigment back to its leuco form through reducing conditions. In the first step, the hair must be swelled under mildly alkaline conditions using urea or ammonia, so the hair fiber can then detach the leuco form. In the second step, a reducing agent, such as sodium dithionite or hydroxyacetone, is applied in excess for approximately one hour at 25–50°C, e.g., 35–40°C. After rinsing and shampooing the hair, a moderate loss of color and shine is observed, sufficient to adjust the shade or correct a given color appearance.

[0064] The dyes are typically selected from the overall dye family "indanthrene" dyes, a synonym for highly stable dyes with excellent fastness properties rather than referring to a specific chemical class. However, most suitable chromophores according to the present disclosure are selected from dyes based on naphthalene, perylene, anthraquinone, and violanthrone backbones. As noted above, they have in common that they lack aromatic amine functionality but possess at least two carbonyl groups that are modified into solubilized sulfate ester intermediates, which are considered reactive color components of this oxidative hair dye system.

[0065] These commercially available dyes are prepared from commercially available vat dye pigments according to standard procedures (see DE 1117242). Reduction is carried out in alkaline medium using n-methylacetamide, potassium boranate, and sodium dithionite, followed by sulfation in the presence of sulfur trioxide and dichloroethane as the solvent. Alternatively, the reaction can be carried out using chlorosulfonic acid with pyridine as the alkalizing agent to give the sulfate ester. This is exemplified for solubilized Vat Green 1 in Scheme 3.

[0066] Scheme 3: JPEG0007759936000003.jpg75167

[0067] Examples of preferred solubilized vat dyes include solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Violet 1 (CAS#1324-57-8), solubilized Vat Yellow 4 (CAS#3564-70-3), solubilized Vat Green 1 (CAS#2538-84-3), solubilized Vat Yellow 1 (CAS#6487-09-8), solubilized Vat Red 34 (CAS#12226-70-9), solubilized Vat Red 1 (CAS#12226-70-9), solubilized Vat Red 2 ... Solubilized Vat Orange 10 (CAS# 10126-90-6), solubilized Vat Orange 9 (CAS# 70356-06-8), solubilized Vat Orange 3 (CAS# 10290-03-6), solubilized Vat Blue 6 (CAS# 2519-28-0), solubilized Vat Yellow 7 (CAS# 3956-62-5), solubilized Vat Brown 1 (CAS# 23725-15-7), and solubilized Vat Blue 20 according to the following structure in Scheme 4:

[0068] Scheme 4: JPEG0007759936000004.jpg74152

[0069] JPEG0007759936000005.jpg70153

[0070] JPEG0007759936000006.jpg90165

[0071] JPEG0007759936000007.jpg81155

[0072] JPEG0007759936000008.jpg86157

[0073] JPEG0007759936000009.jpg65154

[0074] JPEG0007759936000010.jpg60159

[0075] JPEG0007759936000011.jpg80164

[0076] JPEG0007759936000012.jpg84169

[0077] JPEG0007759936000013.jpg86165

[0078] JPEG0007759936000014.jpg61164

[0079] JPEG0007759936000015.jpg66163

[0080] JPEG0007759936000016.jpg87163

[0081] 1.1 New solubilized vat dyes

[0082] In one aspect, the present invention provides novel solubilized vat dyes. Based on the above synthetic concept, additional non-commercially available solubilized vat dyes previously unknown in the literature can be obtained. Surprisingly, it has been found that not only are classic vat dyes exhibiting at least two carbonyl groups and an aromatic polycyclic hydrocarbon moiety useful starting materials, but also known orange, red, blue, and black pigments derived from naphthalene and perylene bis-amidines can be converted to the relevant sulfate ester derivatives. Scheme 5 below shows the conversion of two isomers of indanthrene scarlet (trans-Pigment Orange 43 and cis-Pigment Red 194) to the corresponding sulfate esters (see DE 1117242). The conversion is carried out under standard alkaline and reducing conditions, followed by sulfation using sulfur trioxide.

[0083] Scheme 5: JPEG0007759936000017.jpg89167

[0084] JPEG0007759936000018.jpg88168

[0085]

[0086] The novel solubilized vat dyes can also be obtained starting from commercially available vat dyes as shown in Scheme 6 below:

[0087] Scheme 6: JPEG0007759936000019.jpg47161

[0088] Benzo[lmn]diperimidino[2,1-b:2',1'-i][3,8]phenanthroline-10,21-dione, CAS#4578-87-4 JPEG0007759936000020.jpg42167

[0089] Benzo[lmn]diperimidino[2,1-b:1',2'-j][3,8]phenanthroline-8,11-dione, CAS#20749-67-1 JPEG0007759936000021.jpg40168

[0090] Phenanthro[2”,1”,10”:4,5,6;7”,8”,9”:4',5',6']diisoquino[2,1-a:2',1'-a']diperimidin-8,13-dione, CAS#41635-87-4 JPEG0007759936000022.jpg45170

[0091] Anthra[2”,1”,9”:4,5,6;6”,5”,10”:4',5',6']diisoquino[2,1-a:2',1'-a']diperimidin-12,25-dione, CAS#6859-32-1 JPEG0007759936000023.jpg37165

[0092] Bisbenzimidazo[2,1-a:1',2'-b']anthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline-6,11-dione, CAS#55034-81-6 JPEG0007759936000024.jpg36167

[0093] Bisbenzimidazo[2,1-a:2',1'-a']anthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline-10,21-dione, CAS#55034-79-2 JPEG0007759936000025.jpg50162

[0094] The resulting novel solubilized vat dyes have chemical structures according to formulas (I) to (X) as illustrated in Scheme 7:

[0095] Scheme 7:

[0096] Solubilized Pigment Violet 19 according to (I): JPEG0007759936000026.jpg75164

[0097] Solubilized Pigment Red 122 according to formula (II): JPEG0007759936000027.jpg69169

[0098] Solubilized Pigment Red 194 according to formula (III): JPEG0007759936000028.jpg62169

[0099] Solubilized Pigment Orange 43 according to formula (IV): JPEG0007759936000029.jpg65169

[0100] Solubilized tetraazaviolanthrone-trans-black according to formula (V): JPEG0007759936000030.jpg64163

[0101] Solubilized tetraazaviolanthrone-cis-black according to formula (VI): JPEG0007759936000031.jpg67163

[0102] Solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000032.jpg65163

[0103] Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000033.jpg64167

[0104] Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000034.jpg69168

[0105] Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000035.jpg64168

[0106] 2. Composition for coloring keratin substrates In another aspect, the present invention provides a composition for coloring keratin substrates. The composition comprises an aqueous medium and a solubilized vat dye dissolved in the medium, the solubilized vat dye being a leuco vat dye sulfate ester. The vat dye from which the sulfate ester is derived is preferably selected from anthracene dyes, anthraquinone dyes, naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, pyrene dyes, dibenzo[a,h]pyrene, perylene dyes, terylene dyes, and quaterrylene dyes. The composition is essentially free of oxidation dye precursors selected from primary intermediates and couplers, preferably free of oxidation dye precursors selected from primary intermediates and couplers. Furthermore, the composition is preferably essentially free of reducing agents capable of forming enediols, more preferably free of reducing agents capable of forming enediols. Additionally, the composition is preferably essentially free of sulfur-containing nucleophiles, more preferably free of sulfur-containing nucleophiles.

[0107] According to an embodiment, the composition does not contain a reducing agent. According to another embodiment, the composition contains a reducing agent. When present, the reducing agent is preferably selected from sulfites, pyrosulfites, dithionites, thiosulfates, or combinations thereof. Furthermore, when present, the reducing agent or combination of reducing agents is typically present in an amount of 0.01 to 2.0 wt. %, preferably 0.05 to 1.0 wt. %, based on the weight of the ready-to-use composition.

[0108] According to an embodiment, the composition is essentially free (or preferably free) of at least difunctional Bronsted bases of the general formula XRY, where X and Y are proton-accepting groups and R is an organic moiety comprising 1 to 20 carbon atoms, 0 to 5 oxygen atoms, and 0 to 5 nitrogen atoms, and the at least difunctional Bronsted bases of the general formula XRY have a molecular weight of less than 500 g / mol.

[0109] According to an embodiment, the composition is essentially free (or preferably free) of diamines, aromatic amines, aromatic phenols, or combinations thereof. In particular, the composition is preferably essentially free (or preferably free) of aromatic phenols selected from naphthols, resorcinols, and aminophenols. According to an embodiment, the composition is essentially free (or preferably free) of pigments, parabens, silicones, or combinations thereof.

[0110] According to an embodiment, the composition comprises more than one solubilized vat dye. For example, the composition may comprise two or more, such as three or more, leuco vat dye sulfates.

[0111] According to embodiments, the solubilized vat dye in the composition is selected from anthracene dyes, naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, pyrene dyes, dibenzo[a,h]pyrene, perylene dyes, terylene dyes, quaterrylene dyes, or combinations thereof. According to preferred embodiments, the solubilized vat dye is selected from naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, perylene dyes, terylene dyes, quaterrylene dyes, or combinations thereof. According to particular embodiments, the solubilized vat dye is selected from naphthalene dyes, tetraaza-violanthrone dyes, acridine dyes, perylene dyes, or combinations thereof.

[0112] Specific examples of solubilized vat dyes that may be present in the composition are solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Violet 1 (CAS#1324-57-8), solubilized Vat Yellow 4 (CAS#3564-70-3), solubilized Vat Green 1 (CAS#2538-84-3), solubilized Vat Yellow 1 (CAS#6487-09-8), solubilized Vat Red 34 (CAS#12226-70-9), solubilized solubilized Vat Red 10 (CAS#10126-90-6), solubilized Vat Orange 9 (CAS#70356-06-8), solubilized Vat Orange 3 (CAS#10290-03-6), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Yellow 7 (CAS#3956-62-5), solubilized Vat Brown 1 (CAS#23725-15-7), solubilized Vat Blue 20, or a combination thereof. In particular, solubilized vat dyes that may be present in the composition are solubilized Vat Violet 1 (CAS#1324-57-8), solubilized Vat Green 1 (CAS#2538-84-3), solubilized Vat Yellow 1 (CAS#6487-09-8), solubilized Vat Red 34 (CAS#12226-70-9), solubilized Vat Orange 9 (CAS#70356-06-8), solubilized Vat Orange 3 (CAS#10290-03-6), solubilized Vat Blue 20, or combinations thereof.

[0113] According to an embodiment, the composition may comprise one or more of the novel solubilized vat dyes according to the present disclosure according to formulas (I)-(X):

[0114] Solubilized Pigment Violet 19 according to formula (I): JPEG0007759936000036.jpg75164

[0115] Solubilized Pigment Red 122 according to formula (II): JPEG0007759936000037.jpg69169

[0116] Solubilized Pigment Red 194 according to formula (III): JPEG0007759936000038.jpg62169

[0117] Solubilized Pigment Orange 43 according to formula (IV): JPEG0007759936000039.jpg65169

[0118] Solubilized tetraazaviolanthrone-trans-black according to formula (V): JPEG0007759936000040.jpg64163

[0119] Solubilized tetraazaviolanthrone-cis-black according to formula (VI): JPEG0007759936000041.jpg67163

[0120] Solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000042.jpg65163

[0121] Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000043.jpg64167

[0122] Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000044.jpg69168

[0123] Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000045.jpg64168

[0124] According to certain embodiments, the solubilized vat dye is solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Blue 20, solubilized Perylene-Amidine-Trans-Blue according to formula (VII): JPEG0007759936000046.jpg65163 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000047.jpg64167Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000048.jpg69168Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000049.jpg64168

[0125] or combinations thereof. Compositions comprising one or more of the above solubilized vat dyes are particularly preferred when the composition is intended to be used to correct a brassy color or hue in hair. This is particularly useful for correcting a brassy color or hue in lifted human hair.

[0126] The composition for coloring keratinous substrates according to the present invention comprises an aqueous medium. The medium of the composition may be water alone or water mixed with a volatile polar protic or aprotic organic solvent. Generally, the medium is an aqueous solvent suitable for dissolving the solubilized vat dye. In addition to water, a volatile solvent, including a volatile polar protic or aprotic organic solvent, may be present in the medium. Non-limiting examples of volatile organic solvents include: volatile pyrrolidones such as 1-methylpyrrolidin-2-one; volatile C1-C4 alkanols such as methanol, ethanol, or isopropanol; esters of liquid C2-C6 acids with volatile C1-C8 alcohols such as methyl acetate, n-butyl acetate, ethyl acetate, propyl acetate, isopentyl acetate, or ethyl 3-ethoxypropionate; ketones that are liquid and volatile at room temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone, or acetone; and volatile polyols such as ethylene glycol and propylene glycol.

[0127] It is a particular advantage of the present invention that the composition, and therefore the medium of the composition, may be essentially free of organic solvents, where organic solvents are included, which are preferably selected from ethanol, isopropanol, acetone, and isododecane, or combinations thereof.

[0128] The vehicle may be present in the composition according to the present disclosure in an amount ranging from about 80.0% to about 98.0% by weight, for example, from about 88.0% to about 96.0% by weight, for example, from 90.0% to 94.0% by weight, based on the total weight of the ready-to-use composition.

[0129] Conversely, when the composition includes one solubilized vat dye, the solubilized vat dye may be present in the composition according to the present disclosure in an amount ranging from about 0.1 wt. % to about 5.0 wt. %, such as from about 0.2 wt. % to about 2.0 wt. %, for example, from 0.5 wt. % to 1.0 wt. %, based on the total weight of the ready-to-use composition.

[0130] When the composition includes more than one solubilized vat dye, each solubilized vat dye may be present in the composition according to the present disclosure in an amount ranging from about 0.1% to about 5.0% by weight, for example, from about 0.2% to about 2.0% by weight, for example, from 0.5% to 1.0% by weight, based on the total weight of the ready-to-use composition. The total amount of solubilized vat dyes present in the composition according to the present disclosure preferably does not exceed 7.5% by weight, and more preferably does not exceed 6.0% by weight, based on the total weight of the ready-to-use composition.

[0131] The composition has a pH within a range in which the solubilized vat dye is stable to degradation. In particular, the composition has an alkaline pH, preferably a pH within the range of 8.0 to 10.0. According to an embodiment, the composition has a pH within the range of 8.5 to 9.5, for example, 8.7 to 9.2.

[0132] The composition may contain additional ingredients in addition to the solubilized vat dye and the vehicle. According to an embodiment, the composition further contains one or more penetration enhancers. Suitable penetration enhancers include, for example, ammonia, urea, and monoethanolamine. The penetration enhancer is typically present in an amount ranging from about 5% to about 50% by weight, for example, from about 10% to about 40% by weight, for example, from 15% to 30% by weight, based on the total weight of the ready-to-use composition.

[0133] The composition may further comprise one or more ingredients selected from chelating agents, pH adjusters, fragrances, direct dyes, care ingredients, texture ingredients, vehicle agents, solvents, and surfactants. The chelating agents, pH adjusters, and fragrances are typically present in an amount of less than 1.0 wt. %, typically less than 0.5 wt. %, based on the total weight of the ready-to-use composition. The direct dyes, care ingredients, texture ingredients, vehicle agents, solvents, and surfactants are typically present in an amount of less than 2.0 wt. %, typically less than 1.0 wt. %, based on the total weight of the ready-to-use composition. Overall, such ingredients may typically be present in a cumulative amount of 8.0 wt. % or less, more typically 5.0 wt. % or less, based on the total weight of the ready-to-use composition.

[0134] The compositions for coloring keratinous substrates according to the present disclosure are particularly intended for coloring mammalian hair, preferably human scalp hair.

[0135] 3. Methods for coloring keratin substrates According to one aspect, the present invention provides a method for coloring a keratin substrate. The method for coloring a keratin substrate includes at least steps a1 and b1. Step a1 includes applying composition A to the keratin substrate, composition A including an aqueous medium and a solubilized vat dye dissolved in the medium. The solubilized vat dye is a leuco vat dye sulfate ester, and composition A is essentially free of an oxidation dye precursor selected from a primary intermediate and a coupler. Step b1 includes applying composition B to the keratin substrate, composition B having a pH in the range of 3.0 to 5.0.

[0136] Step a1 is carried out before step b1. Furthermore, step a1 is carried out under conditions in which the leuco vat dye sulfate ester is stable to hydrolysis. Finally, step a1 is carried out long enough so that the solubilized vat dye has sufficient time to diffuse and localize on or within the keratin substrate where the final oxidized vat dye is deposited. For hair dyeing, the solubilized vat dye is allowed to penetrate the hair cortex at 35-40°C for 10-40 minutes, preferably about 37°C for 20-30 minutes, at pH 9.0. Penetration may be enhanced by the presence in composition A of a penetration enhancer such as ammonia, urea, monoethanolamine, or a combination thereof.

[0137] Step b1 is carried out under conditions in which the leuco vat dye sulfate ester is hydrolyzed to the leuco form of the vat dye. Furthermore, step b1 is carried out for a long enough period of time so that the leuco vat dye sulfate ester is hydrolyzed to a sufficient extent. Preferably, step b1 is carried out until at least 90.0%, preferably at least 95.0%, more preferably at least 99.0% of the leuco vat dye sulfate ester is hydrolyzed. Suitable conditions for step b1 at pH 3.0-3.5 include 35-40°C for 5-15 minutes, preferably about 37°C for 8-12 minutes.

[0138] The leuco form of the vat dye obtained from step b1 is susceptible to air oxidation, and therefore no separate oxidation step is required to deposit the pigment form of the vat dye. The final color obtained in the method according to the present disclosure is obtained only after oxidation of the leuco form of the vat dye obtained from step b1 to the pigment form of the vat dye. In the case of hair dyes, air oxidation usually takes about 40-60 minutes to complete, meaning that after 40-60 minutes no further color change is usually easily discernible to the naked eye.

[0139] For example, the method of the present invention for coloring keratinous substrates may optionally include an additional step c1, where accelerated results may be desired. Step c1 involves applying composition C to the keratinous substrate. If included, step c1 is performed after step b1. Composition C contains an oxidizing agent at alkaline pH. In the case of hair dyeing, step c1 primarily results in oxidation of the leuco form of the vat dye, which may or may not also result in hair lift due to oxidation of natural melanin in the hair. Such optional hair lift depends on the oxidizing agent used in composition C, with several levels of hair color lift possible. Suitable conditions for step c1 at pH 9.0 include 15-30 minutes at 35-40°C, preferably 20-25 minutes at about 37°C.

[0140] 3.1 Composition A Composition A, in many embodiments, essentially corresponds to the composition for coloring keratinous substrates described in Chapter 2 above. Composition A comprises an aqueous medium and a solubilized vat dye dissolved in the medium, the solubilized vat dye being a leuco vat dye sulfate ester. Composition A is essentially free of oxidation dye precursors selected from primary intermediates and couplers, and preferably free of oxidation dye precursors selected from primary intermediates and couplers.

[0141] Composition A is further preferably essentially free of reducing agents capable of forming enediols, more preferably free of reducing agents capable of forming enediols.

[0142] According to an embodiment, Composition A does not contain a reducing agent. According to another embodiment, Composition A contains a reducing agent. When present, the reducing agent is preferably selected from sulfites, pyrosulfites, dithionites, thiosulfates, or combinations thereof. Furthermore, when present, the reducing agent or combination of reducing agents is typically present in an amount of 0.01 to 2.0 wt. %, preferably 0.05 to 1.0 wt. %, based on the weight of ready-to-use Composition A.

[0143] Composition A is further preferably essentially free of sulfur-containing nucleophiles, and more preferably free of sulfur-containing nucleophiles.

[0144] According to an embodiment, composition A is essentially free (or preferably free) of at least difunctional Bronsted bases of general formula XRY, where X and Y are proton-accepting groups and R is an organic moiety comprising 1 to 20 carbon atoms, 0 to 5 oxygen atoms and 0 to 5 nitrogen atoms, and the at least difunctional Bronsted bases of general formula XRY have a molecular weight of less than 500 g / mol.

[0145] According to an embodiment, Composition A is essentially free (or preferably free) of diamines, aromatic amines, aromatic phenols, or combinations thereof. In particular, Composition A is preferably essentially free (or preferably free) of aromatic phenols selected from naphthols, resorcinols, and aminophenols. According to an embodiment, Composition A is essentially free (or preferably free) of pigments, parabens, silicones, or combinations thereof.

[0146] According to an embodiment, Composition A comprises more than one solubilized vat dye. For example, Composition A may comprise two or more, such as three or more, leuco vat dye sulfates.

[0147] The vat dye in composition A from which the sulfate ester is derived is preferably selected from anthracene dyes, anthraquinone dyes, naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, pyrene dyes, dibenzo[a,h]pyrene, perylene dyes, terylene dyes, and quaterrylene dyes.

[0148] Further embodiments of Composition A with regard to the selection of chemical classes of solubilized vat dyes or the presence of specific known and / or solubilized vat dyes are as described above in Chapter 2 in the context of compositions for coloring keratinous substrates according to the present disclosure.

[0149] Additionally, the vehicle, amount of solubilized vat dye, pH range, presence of penetration enhancer and / or other ingredients of Composition A are as described above in Section 2 in the context of compositions for coloring keratinous substrates according to the present disclosure.

[0150] 3.2 Composition B Composition B has a pH within the range in which the leuco vat dye sulfate ester is susceptible to decomposition. In particular, the composition has an acidic pH, preferably within the range of 3.0 to 4.5. According to an embodiment, the composition has a pH in the range of 3.2 to 4.0, for example, a pH of about 3.5.

[0151] To provide an acidic environment, Composition B includes an organic or inorganic acid. Suitable organic acids include, for example, carboxylic acids, sulfonic acids, and phosphonic acids. Suitable inorganic acids include, for example, hydrochloric acid, sulfuric acid, boric acid, and carbonic acid. According to an embodiment, Composition B includes a monofunctional organic or inorganic acid. According to a particular embodiment, Composition B includes an acid selected from acetic acid, boric acid, citric acid, tartaric acid, malic acid, maleic acid, fumaric acid, or a combination thereof. For example, Composition B can include citric acid, malic acid, or a combination thereof.

[0152] Otherwise, Composition B comprises an aqueous medium. The medium of Composition B may be water alone or a mixture of water and a volatile polar protic or aprotic organic solvent. In addition to the water present in the medium, a volatile solvent, including a volatile polar protic or aprotic organic solvent, may be present. Non-limiting examples of volatile organic solvents that may be mentioned include: volatile pyrrolidones such as 1-methylpyrrolidin-2-one, volatile C1-C4 alkanols such as methanol, ethanol, or isopropanol; esters of liquid C2-C6 acids with volatile C1-C8 alcohols such as methyl acetate, n-butyl acetate, ethyl acetate, propyl acetate, isopentyl acetate, or ethyl 3-ethoxypropionate; ketones that are liquid and volatile at room temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone, or acetone; and volatile polyols such as ethylene glycol and propylene glycol.

[0153] It is a particular advantage of the present invention that Composition B, and therefore also the medium of the composition, may be essentially free of organic solvents, which, if present, are preferably selected from ethanol, isopropanol, acetone, and isododecane, or combinations thereof.

[0154] The amount of vehicle present in Composition B is such that the vehicle together with the acid and the optional ingredients disclosed below make up 100% by weight of the total ready-to-use composition.

[0155] Composition B may further comprise one or more ingredients selected from chelating agents, fragrances, care ingredients, texture ingredients, vehicle agents, solvents, and surfactants. Chelating agents and fragrances are typically present in an amount of less than 1.0 wt. %, typically less than 0.5 wt. %, based on the total weight of the ready-to-use composition. Care ingredients, texture ingredients, vehicle agents, solvents, and surfactants are typically present in an amount of less than 2.0 wt. %, typically less than 1.0 wt. %, based on the total weight of the ready-to-use composition. Overall, such ingredients may typically be present in a cumulative amount of 8.0 wt. % or less, more typically 5.0 wt. % or less, based on the total weight of the ready-to-use composition.

[0156] 3.3 Composition C Optional composition C has an alkaline pH and contains an oxidizing agent. According to an embodiment, the pH of composition C is in the range of 8.0 to 11.0, in particular in the range of 8.5 to 9.5. According to a particular embodiment, the pH of composition C is about 9.0.

[0157] The oxidizing agent present in Composition C may be any oxidizing agent suitable for promoting the oxidation of the vat dye in its leuco form to a pigment, primarily compared to air oxidation alone. Preferably, the oxidizing agent in Composition C comprises a peroxide, particularly hydrogen peroxide. In the case of hair dyeing, if simultaneous hair lift is desired, the oxidizing agent in Composition C may comprise a persulfate and / or percarbonate, or salts thereof. In accordance with the hair lift embodiment of the present disclosure, Composition C may further comprise a bleach booster. Examples of bleach boosters are C16-C24 fatty alcohols, cyclamate, and saccharin.

[0158] Otherwise, Composition C comprises an aqueous medium. The medium of Composition C may be water alone or water mixed with a volatile polar protic or aprotic organic solvent. In addition to the water present in the medium, a volatile solvent, including a volatile polar protic or aprotic organic solvent, may be present. Non-limiting examples of volatile organic solvents that may be mentioned include: volatile pyrrolidones such as 1-methylpyrrolidin-2-one, volatile C1-C4 alkanols such as methanol, ethanol, or isopropanol; esters of liquid C2-C6 acids with volatile C1-C8 alcohols such as methyl acetate, n-butyl acetate, ethyl acetate, propyl acetate, isopentyl acetate, or ethyl 3-ethoxypropionate; ketones that are liquid and volatile at room temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone, or acetone; and volatile polyols such as ethylene glycol and propylene glycol.

[0159] It is a particular advantage of the present invention that composition C, and therefore the medium of the composition, may be essentially free of organic solvents, which, if present, are preferably selected from ethanol, isopropanol, acetone, and isododecane, or combinations thereof.

[0160] The amount of vehicle present in Composition C is such that the vehicle, together with the alkalizing agent, the oxidizing agent, the optional bleach booster, and the optional ingredients disclosed below, totals 100% by weight of the ready-to-use composition.

[0161] Composition C may further comprise one or more ingredients selected from chelating agents, fragrances, care ingredients, texture ingredients, vehicle agents, solvents, and surfactants. Chelating agents and fragrances are typically present in an amount of less than 1.0 wt. %, typically less than 0.5 wt. %, based on the total weight of the ready-to-use composition. Care ingredients, texture ingredients, vehicle agents, solvents, and surfactants are typically present in an amount of less than 2.0 wt. %, typically less than 1.0 wt. %, based on the total weight of the ready-to-use composition. Overall, such ingredients may typically be present in a cumulative amount of 8.0 wt. % or less, more typically 5.0 wt. % or less, based on the total weight of the ready-to-use composition.

[0162] 3.4 Methods for coloring hair According to a preferred embodiment of the present disclosure, the method for coloring a keratinous substrate is a method for coloring keratinous fibers, in particular natural keratinous fibers. A preferred keratinous substrate is mammalian hair, in particular human scalp hair.

[0163] The method for coloring hair may optionally include any additional treatment of the hair performed by a stylist, particularly any treatment performed together with or in conjunction with coloring the hair. Such treatment may include shampooing, conditioning, post-treating, and / or drying the hair before and / or after implementing the hair coloring method according to the present disclosure. Further optional treatments include hair styling, for example, perming or straightening the hair.

[0164] 4. Methods for correcting brassy color or hue in hair According to one aspect, the present invention provides a method for correcting the brassy color or shade of hair. The method is particularly suitable for correcting the brassy color or shade of lifted mammalian hair, such as human hair. The method for correcting the brassy color or shade of hair comprises at least steps a2 and b2. Step a2 comprises applying composition AA to a keratin substrate, composition AA comprising an aqueous medium and a solubilized vat dye dissolved in the medium. The solubilized vat dye is a leuco vat dye sulfate ester, and composition AA is essentially free of an oxidation dye precursor selected from primary intermediates and couplers. Step b2 comprises applying composition BB to hair, composition B having a pH in the range of 3.0 to 5.0.

[0165] The method for correcting the brassy color or hue of hair differs from the method for coloring keratin substrates described in Chapter 3 above in the following essential respects: the substrate is mammalian hair, in particular human scalp hair, The leuco vat dye sulfate present in composition AA is derived from the vat dye, which imparts an overall blue or bluish color.

[0166] Therefore:

[0167] Step a2 is carried out before step b2. Furthermore, step a2 is carried out under conditions under which the leuco vat dye sulfate ester is stable to hydrolysis. Finally, step a2 is carried out long enough so that the solubilized vat dye has sufficient time to penetrate the hair cortex at pH 9.0 for 10 to 40 minutes at 35-40°C, preferably 20 to 30 minutes at about 37°C. Penetration may be enhanced by the presence in composition AA of a penetration enhancer such as ammonia, urea, monoethanolamine, or a combination thereof.

[0168] Step b2 is carried out under conditions in which the leuco vat dye sulfate ester is hydrolyzed to the leuco form of the vat dye. Furthermore, step b2 is carried out long enough so that the leuco vat dye sulfate ester is hydrolyzed to a sufficient extent. Preferably, step b2 is carried out until at least 90.0%, preferably at least 95.0%, more preferably at least 99.0% of the leuco vat dye sulfate ester is hydrolyzed. Suitable conditions for step b2 at pH 3.0-3.5 include 35-40°C for 5-15 minutes, preferably about 37°C for 8-12 minutes.

[0169] The leuco form of the vat dye obtained from step b2 is susceptible to air oxidation, and therefore, a separate oxidation step is not required to deposit the pigment form of the vat dye. The final color obtained in the method for correcting brassy shade or hue of hair is obtained only after oxidation of the leuco form of the vat dye obtained from step b2 to the pigment form of the vat dye. Air oxidation usually takes about 40-60 minutes to complete, meaning that after 40-60 minutes, no further color change is usually easily discernible to the naked eye.

[0170] Where accelerated results may be desired, for example, for correcting a brassy shade or hue of hair, the method optionally includes an additional step c2. Step c2 comprises applying Composition CC to the hair. If included, step c2 is performed after step b2. Composition CC comprises an oxidizing agent at an alkaline pH. Since additional hair lift is typically not desired in step c2, the oxidizing agent is typically hydrogen peroxide. Where simultaneous lifting of the hair by oxidation of natural melanin in the hair is desired, the oxidizing agent present in Composition CC may comprise persulfates and / or percarbonates, or salts thereof. Suitable conditions for step c2 at pH 9.0 include 5 to 15 minutes at 35 to 40°C, preferably 8 to 12 minutes at about 37°C.

[0171] The method may further comprise the treatments described above in section 3.4, in particular shampooing, conditioning, post-treating and / or drying the hair. Further optional treatments include styling the hair, for example perming or straightening the hair.

[0172] 4.1 Composition AA Composition AA corresponds to Composition A described above in Section 3.1, except for the specific selection of solubilized vat dye and its amount. All other embodiments described above in Section 3.1 for Composition A (or Section 2 for compositions for coloring keratinous substrates) apply equally to Composition AA.

[0173] To make it suitable for correcting a brassy tint or hue in hair, Composition AA includes one or more solubilized vat dyes that impart an overall blue or bluish color (i.e., a color that complements the brassy hue).

[0174] According to a particular embodiment, the solubilized vat dye present in composition AA is solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Blue 20, solubilized Perylene-Amidine-Trans-Blue according to formula (VII): JPEG0007759936000050.jpg65163 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000051.jpg64167 Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000052.jpg69168Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000053.jpg64168

[0175] Or a combination thereof.

[0176] With respect to the amount of solubilized vat dye, when Composition AA contains one solubilized vat dye, the solubilized vat dye may be present in Composition AA in an amount ranging from about 0.01% to about 0.5% by weight, for example, from about 0.02% to about 0.2% by weight, for example, from 0.05% to 0.1% by weight, based on the total weight of the composition. When Composition AA contains more than one solubilized vat dye, each solubilized vat dye may be present in Composition AA in an amount ranging from about 0.01% to about 0.5% by weight, for example, from about 0.02% to about 0.2% by weight, for example, from 0.05% to 0.1% by weight, based on the total weight of the composition. The total amount of solubilized vat dyes present in Composition AA preferably does not exceed 0.75% by weight, more preferably does not exceed 0.6% by weight.

[0177] 4.2 Composition BB Composition BB corresponds to composition B described above in section 3.2. All embodiments described above in section 3.2 for composition B apply equally to composition BB.

[0178] 4.3 Composition CC Optional Composition CC essentially corresponds to Composition C described in Section 3.3 above. In particular, Composition C has an alkaline pH and contains an oxidizing agent. According to an embodiment, the pH of Composition C is in the range of 8.0 to 11.0, in particular in the range of 8.5 to 9.5. According to a particular embodiment, the pH of Composition C is about 9.0.

[0179] The oxidizing agent present in Composition C may be any oxidizing agent suitable for primarily accelerating the oxidation of the vat dye to the pigment in its leuco form, compared to air oxidation alone. Preferably, the oxidizing agent in Composition C comprises a peroxide, particularly hydrogen peroxide. Furthermore, considering that methods for correcting a brassy color or hue of hair are often performed on previously lifted hair, further lifting of the hair may not be desirable. According to an embodiment, methods for correcting a brassy color or hue of hair are often performed on bleached hair. Nevertheless, if further lifting of the hair is intended, the oxidizing agent in Composition CC may comprise a persulfate and / or percarbonate, or salts thereof, and optionally a bleach accelerator.

[0180] The vehicle of Composition CC and the optional additional components of Composition CC are as described in Section 3.3 above in the context of Composition C.

[0181] 5. Methods for changing the color of vat dye-colored keratin substrates According to one aspect, the present invention provides a method for altering the color of a keratinous substrate previously colored with a vat dye or a combination of more than one vat dye. According to an embodiment, the method is for altering the color of a keratinous substrate that has been colored by a method according to the present invention for coloring a keratinous substrate. According to an embodiment, the method is for altering the color of hair that has been colored or modified by a method according to the present invention.

[0182] The method comprises applying to a keratinous substrate composition D. Composition D has a pH in the range of 11.0 to 12.0, in particular a pH of about 11.5.

[0183] Composition D further comprises a reducing agent or a combination of reducing agents. According to an embodiment, the reducing agent or the combination of reducing agents is capable of forming an enediol. For example, the reducing agent may be selected from monohydroxyacetone, dihydroxyacetone, 3-hydroxy-2-butanone, 2-hydroxycyclohexane-1-one, glycolaldehyde, 2-hydroxy-1,2-diphenylethan-1-one, 1,5-dihydroxypentan-2-one, 2,3-dihydroxyacrylaldehyde, 2,3-dihydroxycyclopentan-1-one, or a combination thereof. The reducing agent or the combination of reducing agents is present in ready-to-use Composition D in an amount of 5.0 to 20.0% by volume, preferably 8 to 15.0% by volume, for example 10.0 to 12.0% by volume.

[0184] The reducing agent in Composition D is capable of converting, under fairly harsh alkaline conditions, any vat dyes present on or in the keratin substrate to the corresponding soluble leuco form, which can then be washed off. After application to the hair, Composition D is left on the keratin substrate for 40 to 80 minutes at 30-50°C, followed by rinsing. For bleaching mammalian hair, Composition D is left on the hair, particularly human scalp hair, for 40 to 80 minutes, such as about 60 minutes, at 30-40°C, particularly 37°C, followed by rinsing with water, typically followed by shampooing, optionally followed by conditioning, and blow-drying.

[0185] Composition D may further comprise one or more ingredients selected from chelating agents, fragrances, care ingredients, texture ingredients, vehicle agents, solvents, and surfactants. Chelating agents and fragrances are typically present in an amount of less than 1.0 wt. %, typically less than 0.5 wt. %, based on the total weight of the ready-to-use composition. Care ingredients, texture ingredients, vehicle agents, solvents, and surfactants are typically present in an amount of less than 2.0 wt. %, typically less than 1.0 wt. %, based on the total weight of the ready-to-use composition. Overall, such ingredients may typically be present in a cumulative amount of 8.0 wt. % or less, more typically 5.0 wt. % or less, based on the total weight of the ready-to-use composition.

[0186] In addition to the alkalizing agent, reducing agent, and optional ingredients, Composition D is composed of an aqueous medium. The medium of Composition D may be water alone or a mixture of water and a volatile polar protic or aprotic organic solvent. In addition to the water present in the medium, a volatile solvent, including a volatile polar protic or aprotic organic solvent, may be present. Non-limiting examples of volatile organic solvents include: volatile pyrrolidones such as 1-methylpyrrolidin-2-one; volatile C1-C4 alkanols such as methanol, ethanol, or isopropanol; esters of liquid C2-C6 acids with volatile C1-C8 alcohols such as methyl acetate, n-butyl acetate, ethyl acetate, propyl acetate, isopentyl acetate, or ethyl 3-ethoxypropionate; ketones that are liquid and volatile at room temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone, or acetone; and volatile polyols such as ethylene glycol and propylene glycol.

[0187] It is a particular advantage of the present invention that composition D, and therefore the medium of the composition, may be essentially free of organic solvents, which, if present, are preferably selected from ethanol, isopropanol, acetone, and isododecane, or combinations thereof.

[0188] 6 kits According to one aspect, the present invention provides a kit for coloring keratinous substrates. In particular, the kit may be for coloring keratinous fibers such as mammalian hair, especially human scalp hair.

[0189] The kit includes a first compartment (also referred to herein as compartment A) containing a leuco vat dye sulfate ester or a salt thereof. According to an embodiment, the first compartment contains a mixture of two or more leuco vat dye sulfate esters or salts thereof, for example, three of four leuco vat dye sulfate esters or salts thereof. The kit further includes a second compartment (also referred to herein as compartment B) containing an acid or a salt thereof. According to an embodiment, the second compartment contains a monofunctional organic or inorganic acid, or a salt thereof. According to certain embodiments, the second compartment contains an acid selected from acetic acid, boric acid, citric acid, tartaric acid, malic acid, maleic acid, fumaric acid, a salt thereof, or a combination thereof. For example, the second compartment may contain citric acid, malic acid, a salt thereof, or a combination thereof.

[0190] According to an embodiment, the kit further comprises a third compartment (also referred to herein as compartment C) containing an oxidizing agent. According to an embodiment, the third compartment comprises a peroxide, such as, for example, hydrogen peroxide. Alternatively or in addition to peroxide, the third compartment comprises a persulfate and / or percarbonate, or salts thereof.

[0191] According to an embodiment, the kit further comprises a bleach booster, which may be present in a third compartment or may be provided in a separate compartment.

[0192] According to embodiments, the kit further comprises a fourth compartment (also referred to herein as compartment D) containing a reducing agent or a combination of reducing agents. According to embodiments, the reducing agent or a combination of reducing agents is capable of forming an enediol. For example, the reducing agent may be selected from monohydroxyacetone, dihydroxyacetone, 3-hydroxy-2-butanone, 2-hydroxycyclohexane-1-one, glycolaldehyde, 2-hydroxy-1,2-diphenylethan-1-one, 1,5-dihydroxypentan-2-one, 2,3-dihydroxyacrylaldehyde, 2,3-dihydroxycyclopentan-1-one, or a combination thereof.

[0193] Generally, the contents of each compartment of the kit may be in solid, semi-solid, or liquid form. As used in this context, the term "solid form" refers to powders and similar essentially dry physical forms that are mixed with water or a vehicle before use. As used in this context, the term "semi-solid form" refers to pastes and similar non-flowing concentrated physical forms that are mixed with water or a vehicle before use. As used in this context, the term "liquid form" refers to a ready-to-use form that does not require mixing with water or a vehicle before use.

[0194] In embodiments in which the contents of one or more compartments of the kit are present in solid or semi-solid form, the kit may further comprise one or more compartments containing a medium for mixing with the contents of the one or more compartments. Thus, the kit may further comprise: a compartment containing a medium capable of being mixed with the contents of compartment A to form a composition for coloring keratinous substrates according to the present disclosure (or composition A or composition AA, respectively); and / or a compartment containing a medium capable of forming Composition B or Composition BB, respectively, according to the present disclosure when mixed with the contents of Compartment B, and / or a compartment containing a medium capable of forming a composition C or a composition CC, respectively, according to the present disclosure when mixed with the contents of compartment C; and / or A compartment containing a medium that, when mixed with the contents of compartment D, can form a composition for changing the color of a keratin substrate previously colored with a vat dye or a combination of more than one vat dye according to the present disclosure (composition D).

[0195] In embodiments in which the contents of one or more compartments of the kit are in liquid form, each compartment contains a ready-to-use composition that obviously already contains all the necessary components (optionally) to form compositions A / AA, B / BB, C / CC and / or D according to the present disclosure as described in Sections 3-5 above.

[0196] Furthermore, as described above in Chapters 3 to 5, the compositions for coloring keratinous substrates (or Composition A or Composition AA, respectively) are essentially free of, and preferably free of, certain compounds. According to embodiments, the compositions contain, or preferably do not contain, certain compounds. Similar considerations apply to the contents of Compartment A and any medium for mixing with the contents of Compartment A.

[0197] According to a further embodiment, the kit may further comprise at least one compartment containing one or more leuco vat dye sulfates or salts thereof, resulting in an overall color different from the color provided by the leuco vat dye sulfates in compartment A. Again, the contents of such additional compartments may be in solid, semi-solid, or liquid form. The presence of such additional vat dye-containing compartments may allow the stylist to further individualize the color to suit the customer's desires.

[0198] 7. New solubilized vat dyes, their use, and substrates adsorbed with new solubilized vat dyes According to another aspect, the present invention provides novel leuco vat dye sulfates, heretofore not disclosed in the art. The novel leuco vat dye sulfates corresponding to formulas (I) through (X) are shown herein as follows:

[0199] Solubilized Pigment Violet 19 according to formula (I): JPEG0007759936000054.jpg75164

[0200] Solubilized Pigment Red 122 according to formula (II): JPEG0007759936000055.jpg69169

[0201] Solubilized Pigment Red 194 according to formula (III): JPEG0007759936000056.jpg62169

[0202] Solubilized Pigment Orange 43 according to formula (IV): JPEG0007759936000057.jpg65169

[0203] Solubilized tetraazaviolanthrone-trans-black according to formula (V): JPEG0007759936000058.jpg64163

[0204] Solubilized tetraazaviolanthrone-cis-black according to formula (VI): JPEG0007759936000059.jpg67163

[0205] Solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000060.jpg65163

[0206] Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000061.jpg64167

[0207] Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000062.jpg69168

[0208] Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000063.jpg64168

[0209] According to another aspect, the present disclosure provides the use of leuco vat dye sulfate esters according to formulas (I) to (X) in a vat dyeing process. In particular, the present disclosure contemplates the use of leuco vat dye sulfate esters according to formulas (I) to (X) for coloring keratin substrates. According to a preferred embodiment, the present disclosure contemplates the use of leuco vat dye sulfate esters according to formulas (I) to (X) for coloring mammalian hair, particularly human scalp hair.

[0210] In another aspect, the present invention provides a substrate having adsorbed thereon a leuco vat dye sulfate ester according to formulas (I) to (X) above, or a combination thereof. In some embodiments, the substrate is a fiber. In some embodiments, the substrate is a keratin substrate. For example, the substrate may be a keratin fiber. In certain embodiments, such keratin fiber may be mammalian hair, such as human hair. In other embodiments, such keratin fiber may be a natural fiber, such as wool or silk.

[0211] In yet another embodiment, the substrate can be a cellulosic substrate. For example, the substrate can be selected from natural and / or manufactured cellulosic fibers. Natural cellulosic fibers include, for example, cotton and flax fibers. Manufactured cellulosic fibers include, for example, rayon and viscose fibers.

[0212] 8 Working Example The coloring methods described in the following examples using solubilized vat dyes include the steps of applying a leuco vat dye sulfate ester, hydrolyzing the leuco vat dye sulfate ester to the leuco form, and actively oxidizing the leuco form to the respective insoluble pigment form of the vat dye.

[0213] A. Penetration of solubilized vat dyes into the hair cortex Penetration occurs under mildly alkaline conditions at pH=9 in the presence of other penetration enhancers, such as ammonia or urea. At this point, it is important to maintain the sulfate ester structure intact to avoid premature oxidation of the solubilized vat dye, as this would disrupt the penetration process, leading to incomplete use of the applied dye amount and unsatisfactory color results. To prevent the solubilized vat dye from beginning to oxidize at this point, sodium sulfite may be added to the coloring mixture as a reducing agent. Adding sodium metabisulfite to lower the alkaline pH achieved by the addition of ammonia or urea to pH=6, as described in U.S. Pat. No. 5,364,415 (Lewis et al.), is not beneficial because it would prevent penetration of the solubilized vat dye and reduce the swelling of keratin fibers, which require mildly alkaline conditions. Therefore, the adjustment to a slightly acidic pH must begin before penetration is complete to allow the bulky aromatic chromophore system to flow adequately deep into the swollen hair cortex.

[0214] B. Adjusting pH to a slightly acidic condition The alkaline dye solution is then treated with, for example, acetic acid, ascorbic acid, boric acid, or citric acid to adjust the pH to a slightly acidic level, e.g., pH 3.0 to 3.5. This pH change causes the sulfate esters to hydrolyze, producing the free vat acid (leuco form). This process is typically complete within 10 minutes, after which the solubilized vat dye esters are completely hydrolyzed. At that point, the leuco form is at its most sensitive to oxidizing agents.

[0215] C. Oxidation to deposit insoluble pigments into the hair cortex The hair is briefly rinsed with water to remove any residual dye material from the surface. An optional oxidation step can then be applied. This includes very mild conditions using a 1-12% by volume hydrogen peroxide solution. The following typical concentrations are common in the hair coloring industry: 1.9, 6, 9, or 12% by volume. Hydrogen peroxide can also be applied in conjunction with bleaching agents such as sodium, potassium, or ammonium persulfates or percarbonates. Oxidation, which converts the leuco form to vat dye pigments, is typically completed within 20 minutes. Simultaneous hair lift (where the oxidizing agent continues to oxidize the natural melanin in the hair) is completed within the same time frame. Thus, the overall treatment lasts no longer than an hour, which corresponds well to the application of current oxidative hair colorants without increasing the complexity of the treatment. A key advantage is that the use of organic solvents and alcohols, such as ethanol or isopropyl alcohol, can be completely eliminated in any formulation. In addition, considering that all solubilized vat dyes behave completely equivalently in terms of uniform dye uptake and general fastness properties, they can all be easily blended with each other, allowing formulators to create an unlimited range of natural and fashionable shades.

[0216] D. General Procedures 2 g of urea (penetration enhancer), 200 mg of sodium sulfite (reducing agent), and 120 mg of each solubilized vat dye (color component) are dissolved in 15 ml of water. This simple mixture is already sufficient to obtain the desired color on the hair. In principle, in addition to the above components, all additional components that are typical components of oxidative hair coloring systems can be applied as well, without exception, without adversely affecting the coloring result. This includes the following groups of ingredients: colorants (solubilized vat dyes), penetration enhancers / alkalinizing agents (e.g., ammonia, urea), reducing agents / radical scavengers (e.g., sodium sulfite, etc.), chelating agents (e.g., EDTA, EDDS, ethitronic acid, etc.), fragrances, care ingredients (e.g., hydrolyzed keratin, dimethicone, polyquaterniums, etc.), texture ingredients (e.g., carbomer, cocoamide, hydroxyethylcellulose, etc.), vehicle agents (e.g., cetearyl alcohol, lanolin alcohol, glyceryl stearate, etc.), and surfactants (e.g., lauryl ether sulfate, lauryl sulfoacetate, etc.).

[0217] The solution is gently heated to 40°C, and one or two strands of hair are placed in the color bath for 25-30 minutes. The strands are then removed and set aside, and the solution is treated with acetic acid to a pH of 3.0-3.5. (Setting the strands aside makes them difficult to separate at the end of treatment, but is only useful in lab experiments to avoid damaging the strands during the pH change, which is not an issue in actual head application.) The strands are then returned to the container and left for another 10 minutes.

[0218] The hair strands are then removed and briefly rinsed with water, followed by an oxidizing bath at 40°C containing a standard commercial product containing hydrogen peroxide, known as a color developer. Typical contents are 1.9, 6, 9, and 12% by volume. The color developer can be chosen freely depending on the desired level of lift. The oxidizing bath may also contain a hydrogen peroxide-containing color developer and a bleaching powder containing a typical oxidizing agent, such as sodium, potassium, or ammonium persulfate or percarbonate. This treatment results in maximum lift / bleaching of the hair, including simultaneous coloring. After 20 minutes, the hair strands are removed and rinsed with warm water to completely remove any traces of oxidizing agent, powdered particles, etc., washed with shampoo, then post-treated with a commercial conditioner, and finally dried with a blow dryer. This post-treatment reseals the hair cortex, restoring the hair to its original state with a closed, healthy surface.

[0219] The following table (Scheme 8) summarizes the coloration obtained using the solubilized form of each vat dye on hair tresses using different hair types and oxidation levels.

[0220] Scheme 8: JPEG0007759936000064.jpg251168JPEG0007759936000065.jpg255159JPEG0007759936000066.jpg107170

[0221] E Comparison of color and color retention with commercially available products A hair tress (natural blonde) is colored using the solubilized form of Vat Yellow 4 as described above or, respectively, using the commercial shade in a salon test.

[0222] The commercial shades tested were Magma limoncello and Vidal Sassoon yellow, both commercial brands from Wella Company ("Wella Professionals"). Color retention is determined immediately after application ("Fresh ON"), after 5 shampoo washes, and after 10 shampoo washes.

[0223] The following table (Scheme 9) summarizes the colors obtained using Vat Yellow 4 or the commercial shade Magma limoncello or the commercial shade Vidal Sassoon yellow, respectively.

[0224] Scheme 9: JPEG0007759936000067.jpg44168

[0225] The coloring results obtained and color retention after 5 and 10 shampoo washes are shown in Figures 11 to 13.

[0226] Figures 11a and 11b show the colouring obtained in the salon test immediately after colouring ("Fresh ON"), comparing Vat Yellow 4 with Magma limoncello and Vidal Sassoon Yellow.

[0227] Figures 12a and 12b show the color retention after 5 washes comparing Vat Yellow 4 with Magma limoncello and Vidal Sassoon Yellow.

[0228] Figures 13a and 13b show the color retention after 5 washes comparing Vat Yellow 4 with Magma limoncello and Vidal Sassoon Yellow.

[0229] F. Procedures for adjusting completed coloring for corrective purposes Dissolve 2 g of urea in 15 ml of water. The pH is carefully adjusted to pH 11.5 with 32% caustic soda (NaOH), followed by the slow addition of 10% by volume of hydroxyacetone, and heat the mixture to 40°C. A hair strand colored with the solubilized and subsequently oxidized vat dyes according to the procedure described above is placed in this alkaline solution and held completely covered with the solution at 40°C for 1 hour. The hair strand is then removed, rinsed with water, shampooed, treated with a commercial conditioner, and finally blow-dried. The remaining alkaline solution is significantly colored as the respective vat dyes are removed. The color that disappears from the hair strand depends on the dyes previously used to color the hair strand.

[0230] The following table (Scheme 10) summarizes the colours obtained using Vat Violet 1 or Vat Yellow 4, respectively, and the modifications / adjustments obtained by treatment with reducing agents.

[0231] Scheme 10: JPEG0007759936000068.jpg109170

[0232] G. Procedure for Correcting Brassiness The following table (Scheme 11) summarizes the observed color modifications / tuning obtained using solubilized Vat Blue 4.

[0233] Scheme 11: JPEG0007759936000069.jpg112170

[0234] The following description further illustrates the present invention. 1. A method for coloring a keratin substrate, comprising: a1 applying composition A to the keratin substrate, wherein composition A comprises an aqueous medium and a solubilized vat dye dissolved in the medium, the solubilized vat dye being a leuco vat dye sulfate, and composition A is essentially free of oxidation dye precursors selected from primary intermediates and couplers; b1 applying composition B to the keratin substrate, wherein composition B has a pH in the range of 3.0 to 5.0; A method comprising: 2. The method of statement 1, wherein composition A is essentially free of reducing agents capable of forming enediols. 3. The method of statement 1, wherein composition A is essentially free of reducing agents. 4. The method of statement 1, wherein composition A further comprises a reducing agent selected from sulfites, pyrosulfites, dithionites, thiosulfates, or combinations thereof. 5. A method according to any of the preceding statements, wherein Composition A is essentially free of sulfur-containing nucleophiles. 6. The method of any of the preceding statements, wherein composition A is essentially free of at least difunctional Bronsted bases of general formula XRY, where X and Y are proton-accepting groups and R is an organic moiety containing 1 to 20 carbon atoms, 0 to 5 oxygen atoms and 0 to 5 nitrogen atoms, and the at least difunctional Bronsted bases of general formula XRY have a molecular weight of less than 500 g / mol. 7. The method of any of the preceding statements, wherein Composition A is essentially free of diamines, aromatic amines, aromatic phenols, or combinations thereof. 8. The method of any of the preceding statements, wherein Composition A is essentially free of pigments, parabens, silicones, or combinations thereof. 9. A method according to any of the preceding statements, wherein composition A comprises two or more solubilized vat dyes. 10. The method of any of the preceding statements, wherein the solubilized vat dye in Composition A is selected from an anthracene dye, an anthraquinone dye, a naphthalene dye, a violanthrone dye, a tetraaza-violanthrone dye, an acridine dye, a pyrene dye, a dibenzo[a,h]pyrene, a perylene dye, a terrylene dye, a quaterrylene dye, or a combination thereof. 11. The method of any of the preceding statements, wherein the solubilized vat dye in composition A is selected from an anthracene dye, a naphthalene dye, a violanthrone dye, a tetraaza-violanthrone dye, an acridine dye, a pyrene dye, a dibenzo[a,h]pyrene, a perylene dye, a terrylene dye, a quaterrylene dye, or a combination thereof. 12. The method of any of the preceding statements, wherein the solubilized vat dye in Composition A is selected from a naphthalene dye, a violanthrone dye, a tetraaza-violanthrone dye, an acridine dye, a perylene dye, a terrylene dye, a quaterrylene dye, or a combination thereof. 13. The method of any of the preceding statements, wherein the solubilized vat dye in composition A is selected from a naphthalene dye, a tetraaza-violanthrone dye, an acridine dye, a perylene dye, or a combination thereof. 14 The solubilized vat dyes in composition A are solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Violet 1 (CAS#1324-57-8), solubilized Vat Yellow 4 (CAS#3564-70-3), solubilized Vat Green 1 (CAS#2538-84-3), solubilized Vat Yellow 1 (CAS#6487-09-8), solubilized Vat Red 34 (CAS#12226-70-9), solubilized Vat Red 10 (CAS# 10126-90-6), solubilized Vat Orange 9 (CAS#70356-06-8), solubilized Vat Orange 3 (CAS#10290-03-6), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Yellow 7 (CAS#3956-62-5), solubilized Vat Brown 1 (CAS#23725-15-7), solubilized Vat Blue 20, or a combination thereof. 15. The method of any of statements 1-13, wherein the solubilized vat dye in composition A is selected from solubilized Vat Violet 1 (CAS#1324-57-8), solubilized Vat Green 1 (CAS#2538-84-3), solubilized Vat Yellow 1 (CAS#6487-09-8), solubilized Vat Red 34 (CAS#12226-70-9), solubilized Vat Orange 9 (CAS#70356-06-8), solubilized Vat Orange 3 (CAS#10290-03-6), solubilized Vat Blue 20, or a combination thereof. 16 Composition A is a compound represented by the formulas (I) to (X): Solubilized Pigment Violet 19 according to formula (I): JPEG0007759936000070.jpg75164 Solubilized Pigment Red 122 according to formula (II): JPEG0007759936000071.jpg69169Solubilized Pigment Red 194 according to formula (III): JPEG0007759936000072.jpg62169Solubilized Pigment Orange 43 according to formula (IV): JPEG0007759936000073.jpg65169 Solubilized tetraazaviolanthrone-trans-black according to formula (V): JPEG0007759936000074.jpg64163 Solubilized tetraazaviolanthrone-cis-black according to formula (VI): JPEG0007759936000075.jpg67163 Solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000076.jpg65163 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000077.jpg64167Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000078.jpg69168Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000079.jpg64168 or a combination thereof. 17. A method according to any of the preceding claims, wherein composition A has a pH in the range of 8.0 to 10.0, in particular a pH in the range of 8.5 to 9.5. 18. A method according to any preceding statement, wherein composition A further comprises a penetration enhancer. 19. The method of statement 18, wherein the penetration enhancer is selected from ammonia, urea, monoethanolamine, or a combination thereof. 20. A method according to any of the preceding statements, wherein composition A further comprises one or more ingredients selected from pH adjusters, chelating agents, direct dyes, fragrances, care ingredients, texture ingredients, vehicle agents, solvents, and surfactants. 21. A method according to any of the preceding statements, wherein composition B has a pH in the range of 3.2 to 4.0, such as a pH of about 3.5. 22. A method according to any of the preceding statements, wherein composition B comprises a monofunctional organic or inorganic acid. 23. The method of any of statements 1-21, wherein composition B comprises an acid selected from acetic acid, boric acid, citric acid, tartaric acid, malic acid, maleic acid, fumaric acid, or a combination thereof, in particular composition B comprises citric acid, malic acid, or a combination thereof. 24. A method according to any of the preceding claims, comprising: c applying composition C to said keratinous substrate, said composition C comprising an oxidizing agent. 25. The method of claim 24, wherein composition C has a pH in the range of 8.0 to 11.0, particularly in the range of 8.5 to 9.5, such as a pH of about 9.0. 26. The method of claim 24 or 25, wherein the oxidizing agent in composition C comprises a peroxide, particularly hydrogen peroxide. 27. The method of any of statements 24-26, wherein the oxidizing agent in composition C comprises a persulfate and / or a percarbonate. 28. The method of any of statements 24-27, wherein composition C further comprises a bleach booster. 29. A method according to any of the preceding statements, wherein the keratin substrate is mammalian hair, in particular human scalp hair. 30. The method of statement 29, further comprising styling the hair. 31. The method of statement 30, wherein styling the hair comprises perming or straightening the hair. 32. The method of any of statements 29-31, further comprising shampooing, conditioning, post-treating, and / or drying the hair. 33 A method for correcting brassy color or hue in mammalian hair, comprising: a2 applying composition AA to hair, said composition AA comprising an aqueous medium and a solubilized vat dye dissolved in said medium, said solubilized vat dye being a leuco vat dye sulfate ester, and composition AA being essentially free of oxidation dye precursors selected from primary intermediates and couplers; b2. A step of applying composition BB to hair, wherein said composition BB has a pH in the range of 3.0 to 5.0. A method comprising: 34. The method of statement 33, wherein composition AA is essentially free of reducing agents capable of forming enediols. 35. The method of statement 33, wherein composition AA is essentially free of reducing agents. 36. The method of statement 33, wherein composition AA further comprises a reducing agent selected from a sulfite, a pyrosulfite, a dithionite, a thiosulfate, or a combination thereof. 37. The method of any of statements 33-36, wherein composition AA is essentially free of sulfur-containing nucleophiles. 38. The method of any of statements 33-37, wherein composition AA is essentially free of at least difunctional Bronsted bases of the general formula XRY, where X and Y are proton-accepting groups and R is an organic moiety containing 1 to 20 carbon atoms, 0 to 5 oxygen atoms, and 0 to 5 nitrogen atoms, and the at least difunctional Bronsted bases of the general formula XRY have a molecular weight of less than 500 g / mol. 39. The method of any of statements 33-38, wherein composition AA is essentially free of diamines, aromatic amines, aromatic phenols, or combinations thereof. 40. The method of any of statements 33-39, wherein composition AA is essentially free of pigments, parabens, silicones, or combinations thereof. 41. The method of any of statements 33-40, wherein composition AA comprises two or more solubilized vat dyes. 42. The method of any of statements 33-41, wherein the solubilized vat dye in composition AA is derived from a vat dye or combination of vat dyes that imparts an overall blue or bluish color. 43 The solubilized vat dye in composition AA is solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Blue 20, solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000080.jpg65163 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000081.jpg64167Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000082.jpg69168Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000083.jpg64168, or a combination thereof. 44. The method of any of statements 33 to 43, wherein composition AA has a pH in the range of 8.0 to 10.0, particularly a pH in the range of 8.5 to 9.5. 45. The method of any of statements 33-44, wherein composition AA further comprises a penetration enhancer. 46. ​​The method of statement 45, wherein the penetration enhancer is selected from ammonia, urea, monoethanolamine, or a combination thereof. 47. The method of any of statements 33-46, wherein composition AA further comprises one or more ingredients selected from a pH adjuster, a chelating agent, a direct dye, a fragrance, a care ingredient, a texture ingredient, a vehicle agent, a solvent, and a surfactant. 48. The method of any of statements 33-47, wherein Composition BB has a pH in the range of 3.2 to 4.0, such as a pH of about 3.5. 49. The method of any of statements 33-48, wherein composition BB comprises a monofunctional organic or inorganic acid. 50. The method of any of statements 33-49, wherein composition BB comprises an acid selected from acetic acid, boric acid, citric acid, tartaric acid, malic acid, maleic acid, fumaric acid, or a combination thereof, and in particular composition B comprises citric acid, malic acid, or a combination thereof. 51 Furthermore, 51. The method of any of statements 33 to 50, further comprising the step of applying composition CC to the keratinous substrate, wherein composition CC comprises an oxidizing agent. 52. The method of statement 51, wherein composition CC has a pH in the range of 8.0 to 11.0, particularly in the range of 8.5 to 9.5, such as a pH of about 9.0. 53. The method of statements 51 or 52, wherein the oxidizing agent in composition CC comprises a peroxide, particularly hydrogen peroxide. 54. The method of any of statements 33 to 53, wherein the mammalian hair is lifted mammalian hair. 55. The method of statement 54, wherein the lifted mammalian hair is bleached mammalian hair. 56. The method of any of statements 33 to 55, wherein the mammalian hair is human hair. 57. The method of any of statements 33-56, further comprising styling the hair. 58. The method of statement 57, wherein styling the hair comprises perming or straightening the hair. 59. The method of any of statements 33-58, further comprising shampooing, conditioning, post-treating and / or drying the hair. 60 A method for changing the color of a vat dye-colored keratin substrate, comprising applying to the keratin substrate a composition D having a pH in the range of 11.0 to 12.0, wherein composition D further comprises a reducing agent. 61. The method of statement 61, wherein the reducing agent is selected from monohydroxyacetone, dihydroxyacetone, 3-hydroxy-2-butanone, 2-hydroxycyclohexan-1-one, glycolaldehyde, 2-hydroxy-1,2-diphenylethan-1-one, 1,5-dihydroxy-pentan-2-one, 2,3-dihydroxy-acrylaldehyde, 2,3-dihydroxy-cyclopentan-1-one, or a combination thereof. 62. A composition for coloring keratinous substrates, comprising an aqueous medium and a solubilized vat dye dissolved in the medium, wherein the solubilized vat dye is a leuco vat dye sulfate ester, and the vat dye is selected from anthracene dyes, anthraquinone dyes, naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, pyrene dyes, dibenzo[a,h]pyrene, perylene dyes, terylene dyes, and quaterrylene dyes; the composition is essentially free of oxidation dye precursors selected from primary intermediates and couplers; the composition is essentially free of reducing agents capable of forming enediols; and the composition is essentially free of sulfur-containing nucleophiles. 63. The composition of statement 62, wherein the composition is essentially free of a reducing agent. 64. The composition of statement 62, wherein the composition further comprises a reducing agent selected from a sulfite, a pyrosulfite, a dithionite, a thiosulfate, or a combination thereof. 65. The composition of any of statements 62-64, wherein the composition is essentially free of at least difunctional Bronsted bases of the general formula XRY, where X and Y are proton-accepting groups and R is an organic moiety containing 1 to 20 carbon atoms, 0 to 5 oxygen atoms, and 0 to 5 nitrogen atoms, and the at least difunctional Bronsted bases of the general formula XRY have a molecular weight of less than 500 g / mol. 66. The composition of any of statements 62-65, essentially free of diamines, aromatic amines, aromatic phenols, or combinations thereof. 67. The composition of any of statements 62-66, essentially free of pigments, parabens, silicones, or combinations thereof. 68. A composition according to any of statements 62-67, comprising two or more leuco vat dye sulfates. 69. The composition of any of statements 62-68, wherein the vat dye is selected from an anthracene dye, a naphthalene dye, a violanthrone dye, a tetraaza-violanthrone dye, an acridine dye, a pyrene dye, a dibenzo[a,h]pyrene, a perylene dye, a terrylene dye, a quaterrylene dye, or a combination thereof. 70. The composition of any of statements 62-69, wherein the vat dye is selected from a naphthalene dye, a violanthrone dye, a tetraaza-violanthrone dye, an acridine dye, a perylene dye, a terrylene dye, a quaterrylene dye, or a combination thereof. 71. The composition of any of statements 62-70, wherein the vat dye is selected from a naphthalene dye, a tetraaza-violanthrone dye, an acridine dye, a perylene dye, or a combination thereof. 72 The solubilized vat dye is selected from the group consisting of solubilized vat blue 4 (CAS#747-19-5), solubilized vat violet 1 (CAS#1324-57-8), solubilized vat yellow 4 (CAS#3564-70-3), solubilized vat green 1 (CAS#2538-84-3), solubilized vat yellow 1 (CAS#6487-09-8), solubilized vat red 34 (CAS#12226-70-9), solubilized vat red 10 (CAS#1012 6-90-6), solubilized Vat Orange 9 (CAS#70356-06-8), solubilized Vat Orange 3 (CAS#10290-03-6), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Yellow 7 (CAS#3956-62-5), solubilized Vat Brown 1 (CAS#23725-15-7), solubilized Vat Blue 20, or a combination thereof. 73. The composition of any of statements 62-71, wherein the solubilized vat dye is selected from solubilized Vat Violet 1 (CAS#1324-57-8), solubilized Vat Green 1 (CAS#2538-84-3), solubilized Vat Yellow 1 (CAS#6487-09-8), solubilized Vat Red 34 (CAS#12226-70-9), solubilized Vat Orange 9 (CAS#70356-06-8), solubilized Vat Orange 3 (CAS#10290-03-6), solubilized Vat Blue 20, or a combination thereof. 74 Formula (I)~(X): Solubilized Pigment Violet 19 according to formula (I): JPEG0007759936000084.jpg75164Solubilized Pigment Red 122 according to formula (II): JPEG0007759936000085.jpg69169Solubilized Pigment Red 194 according to formula (III): JPEG0007759936000086.jpg62169Solubilized Pigment Orange 43 according to formula (IV): JPEG0007759936000087.jpg65169 Solubilized tetraazaviolanthrone-trans-black according to formula (V): JPEG0007759936000088.jpg64163 Solubilized tetraazaviolanthrone-cis-black according to formula (VI): JPEG0007759936000089.jpg67163 Solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000090.jpg65163 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000091.jpg64167 Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000092.jpg69168Solubilized naphthalene-amidine-cis-blue according to formula (X): 74. The composition of any of statements 62 to 73, comprising a solubilized vat dye according to any one of: JPEG0007759936000093.jpg64168; 75 The solubilized vat dye is derived from a vat dye or a combination of vat dyes that imparts an overall blue or bluish color, particularly, the solubilized vat dye is selected from the group consisting of solubilized Vat Blue 4 (CAS#747-19-5), solubilized Vat Blue 6 (CAS#2519-28-0), solubilized Vat Blue 20, solubilized Perylene-Amidine-Trans Blue according to formula (VII): JPEG0007759936000094.jpg65163 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000095.jpg64167 Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000096.jpg69168Solubilized naphthalene-amidine-cis-blue according to formula (X): 72. The composition of any of statements 62 to 71, wherein the solubilized blue vat dye is selected from the group consisting of: JPEG0007759936000097.jpg64168; 76. A composition according to any of statements 62 to 75, wherein the composition has a pH of 8.0 to 10.0, particularly a pH of 8.5 to 9.5. 77. The composition of any of statements 62-76, wherein the composition further comprises a penetration enhancer, particularly a penetration enhancer selected from ammonia, urea, monoethanolamine, or a combination thereof. 78. The composition of any of statements 62-77, wherein the composition further comprises one or more ingredients selected from a pH adjuster, a chelating agent, a direct dye, a fragrance, a care ingredient, a texture ingredient, a vehicle agent, a solvent, and a surfactant. 79. A composition according to any of statements 62 to 78, wherein the keratin substrate is mammalian hair, in particular human scalp hair. 80 A kit for coloring keratin substrates, comprising: Compartment A containing leuco vat dye sulfate ester or its salt, Compartment B containing the acid or its salt Includes a kit. 81. The kit of statement 80, wherein compartment A contains a mixture of two or more leuco vat dye sulfate esters or salts thereof. 82. The kit of statement 80 or 81, wherein compartment B contains a monofunctional organic or inorganic acid. 83. The kit of statements 80 or 81, wherein compartment B comprises an acid selected from acetic acid, boric acid, citric acid, tartaric acid, malic acid, maleic acid, fumaric acid, or a combination thereof, in particular composition B comprises citric acid, malic acid, or a combination thereof. 84. A kit according to any of statements 81-83, further comprising a compartment C containing an oxidizing agent. 85. The kit of statement 84, wherein compartment C contains a peroxide, particularly hydrogen peroxide. 86. The kit of statement 84 or 85, wherein compartment C contains persulfate and / or percarbonate. 87. The kit of any of statements 83-86, wherein the kit further comprises a bleach booster. 88. The kit of any of statements 80-87, further comprising a compartment D containing a reducing agent. 89. The kit of statement 88, wherein the reducing agent is selected from monohydroxyacetone, dihydroxyacetone, 3-hydroxy-2-butanone, 2-hydroxycyclohexane-1-one, glycolaldehyde, 2-hydroxy-1,2-diphenylethan-1-one, 1,5-dihydroxy-pentan-2-one, 2,3-dihydroxy-acrylaldehyde, 2,3-dihydroxy-cyclopentan-1-one, or a combination thereof. 90. A kit according to any of statements 80 to 89, wherein the contents of compartment A and / or compartment B and / or compartment C and / or compartment D are present in solid form or semi-solid form or liquid form. 91 A kit according to any one of claims 80 to 90, a compartment containing a medium capable of forming composition A used in step (a) of statement 1 when mixed with the contents of compartment A; a compartment containing a medium capable of forming composition B used in step (b) of statement 1 when mixed with the contents of compartment B; a compartment containing a medium capable of forming composition C used in step (c) of statement 1 when mixed with the contents of compartment C; and / or a compartment containing a medium capable of forming composition D used in statement 61 when mixed with the contents of compartment D; The kit further comprises: 92. A kit according to any of statements 80-91, further comprising at least one compartment containing one or more leuco vat dye sulfates or salts thereof that produce an overall color different from the color produced by the leuco vat dye sulfate in compartment A. 93 Solubilized Pigment Violet 19 according to formula (I): JPEG0007759936000098.jpg7516494 Solubilized Pigment Red 122 according to formula (II): JPEG0007759936000099.jpg6916995 Solubilized Pigment Red 194 according to formula (III): JPEG0007759936000100.jpg6216996 Solubilized Pigment Orange 43 according to formula (IV): JPEG0007759936000101.jpg6516997 Solubilized tetraazaviolanthrone-trans-black according to formula (V): JPEG0007759936000102.jpg6416398 Solubilized tetraazaviolanthrone-cis-black according to formula (VI): JPEG0007759936000103.jpg6716399 Solubilized perylene-amidine-trans-blue according to formula (VII): JPEG0007759936000104.jpg65163100 Solubilized perylene-amidine-cis-blue according to formula (VIII): JPEG0007759936000105.jpg64167101 Solubilized naphthalene-amidine-trans-blue according to formula (IX): JPEG0007759936000106.jpg69168102 Solubilized naphthalene-amidine-cis-blue according to formula (X): JPEG0007759936000107.jpg64168103 Use of a leuco vat dye sulfate ester according to any one of descriptions 93 to 102 in a vat dyeing method. 104. Use of a leuco vat dye sulfate according to any of statements 93 to 102 for colouring keratin substrates. 105. Use of a leuco vat dye sulfate ester according to any of statements 93 to 102 for colouring mammalian hair, in particular human scalp hair. 106. A substrate having adsorbed thereon a leuco vat dye sulfate ester according to any one of statements 93 to 102. 107. The substrate of statement 106, wherein the substrate is a fiber. 108. The substrate of statement 106 or 107, wherein the substrate is a keratin substrate. 109. The substrate of any of statements 106-108, wherein the substrate is mammalian hair. 110. The substrate of statement 109, wherein the substrate is human hair. 111. The substrate of statement 109, wherein the substrate is selected from wool and silk. 112. The substrate of statements 106 or 107, wherein the substrate is a cellulosic substrate. 113. The substrate of statement 112, wherein the substrate is selected from natural and manufactured cellulosic fibers.

Claims

1. 1. A method for coloring a keratin substrate, comprising: a1 applying composition A to the keratin substrate, wherein composition A comprises an aqueous medium and a solubilized vat dye dissolved in the medium, wherein the solubilized vat dye is a leuco vat dye sulfate ester, and composition A is essentially free of oxidation dye precursors selected from primary intermediates and couplers; b1. applying composition B to the keratinous substrate, said composition B comprising an organic or inorganic acid and an aqueous medium, said composition B having a pH in the range of 3.0 to 5.0; wherein step a1 is performed before step b1.

2. 10. The method of claim 1, wherein Composition A is essentially free of reducing agents capable of forming enediols.

3. 3. The method of claim 1 or 2, wherein Composition A is essentially free of diamines, aromatic amines, aromatic phenols, pigments, parabens, silicones, or combinations thereof.

4. 4. The method of claim 1, wherein composition A comprises two or more solubilized vat dyes.

5. 5. The method of any one of claims 1 to 4, wherein the solubilized vat dye in Composition A is selected from anthracene dyes, anthraquinone dyes, naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, pyrene dyes, dibenzo[a,h]pyrene, perylene dyes, terrylene dyes, quaterrylene dyes, or combinations thereof.

6. 6. The method of any one of claims 1 to 5, wherein composition A has a pH in the range of 8.0 to 10.

0.

7. 7. The method of claim 6, wherein composition A has a pH in the range of 8.5 to 9.

5.

8. 8. The method of claim 1, wherein composition A further comprises a penetration enhancer.

9. 9. The method of claim 8, wherein the penetration enhancer is selected from ammonia, urea, monoethanolamine, or a combination thereof.

10. 10. The method of any one of claims 1 to 9, wherein composition B has a pH in the range of 3.2 to 4.

0.

11. c1. Applying composition C to the keratinous substrate, wherein composition C comprises an oxidizing agent.

11. The method of claim 1 , further comprising: step c1 being performed after step b1.

12. 12. The method of claim 11, wherein composition C has a pH in the range of 8.0 to 11.

0.

13. 13. The method of claim 12, wherein composition C has a pH in the range of 8.5 to 9.

5.

14. 14. The method of any one of claims 11 to 13, wherein the oxidizing agent in Composition C comprises a peroxide, a persulfate, a percarbonate, or a combination thereof.

15. 15. The method of any one of claims 1 to 14, wherein the keratin substrate is mammalian hair.

16. 16. The method of claim 15, wherein the mammalian hair is human scalp hair.

17. 1. A method for correcting brassy color or hue in mammalian hair, comprising: a2 applying composition AA to hair, said composition AA comprising an aqueous medium and a solubilized vat dye dissolved in said medium, said solubilized vat dye being a leuco vat dye sulfate ester, and composition AA being essentially free of oxidation dye precursors selected from primary intermediates and couplers; b2. applying composition BB to hair, wherein composition BB comprises an organic or inorganic acid and an aqueous medium, and composition BB has a pH in the range of 3.0 to 5.

0. wherein step a2 is performed before step b2.

18. 18. The method of claim 17, wherein composition AA comprises two or more solubilized vat dyes.

19. 19. The method of claim 17 or 18, wherein the solubilized vat dye in composition AA is derived from a vat dye or combination of vat dyes that imparts an overall blue or bluish color.

20. 20. The method of any one of claims 17 to 19, wherein Composition AA has a pH in the range of 8.0 to 10.

0.

21. 21. The method of any one of claims 17 to 20, wherein composition AA has a pH in the range of 8.5 to 9.

5.

22. 22. The method of any one of claims 17 to 21, wherein composition BB has a pH in the range of 3.2 to 4.

0.

23. c2. applying a composition CC to the hair, the composition CC comprising an oxidizing agent; 23. The method of claim 17, further comprising: step c2 being performed after step b2.

24. 24. The method of claim 23, wherein composition CC has a pH in the range of 8.0 to 11.

0.

25. 25. The method of claim 23 or 24, wherein composition CC has a pH in the range of 8.5 to 9.

5.

26. 1. A method for changing the color of a vat dye-colored keratin substrate comprising applying to the keratin substrate composition D having a pH in the range of 11.0 to 12.0, the composition D including a reducing agent.

27. 27. The method of claim 26, wherein the reducing agent is selected from monohydroxyacetone, dihydroxyacetone, 3-hydroxy-2-butanone, 2-hydroxycyclohexan-1-one, glycolaldehyde, 2-hydroxy-1,2-diphenylethan-1-one, 1,5-dihydroxy-pentan-2-one, 2,3-dihydroxy-acrylaldehyde, 2,3-dihydroxy-cyclopentan-1-one, or combinations thereof.

28. 1. A composition for coloring keratinous substrates, comprising an aqueous medium and a solubilized vat dye dissolved in the medium, wherein the solubilized vat dye is a leuco vat dye sulfate ester, and the vat dye is selected from anthracene dyes, anthraquinone dyes, naphthalene dyes, violanthrone dyes, tetraaza-violanthrone dyes, acridine dyes, pyrene dyes, dibenzo[a,h]pyrene, perylene dyes, terylene dyes, and quaterrylene dyes; the composition is essentially free of oxidation dye precursors selected from primary intermediates and couplers; and the composition is essentially free of reducing agents capable of forming enediols.

29. 30. The composition of claim 28, essentially free of diamines, aromatic amines, aromatic phenols, pigments, parabens, silicones, or combinations thereof.

30. 30. The composition of claim 28 or 29, comprising two or more leuco vat dye sulfates.

31. 31. The composition of any one of claims 28 to 30, wherein the solubilized vat dye is derived from a vat dye or combination of vat dyes that imparts an overall blue or bluish color.

32. 32. The composition of any one of claims 28 to 31, wherein the composition has a pH of 8.0 to 10.

0.

33. 33. The composition of any one of claims 28 to 32, wherein the composition has a pH of 8.5 to 9.

5.

34. Compartment A containing a leuco vat dye sulfate or its salt, Compartment B containing an organic or inorganic acid or its salt, Compartment D containing the reducing agent 1. A kit for coloring a keratin substrate, comprising:

35. 35. The kit of claim 34, wherein compartment A contains a mixture of two or more leuco vat dye sulfate esters or salts thereof.

36. 36. The kit of claim 34 or 35, further comprising a compartment C containing an oxidizing agent.

37. 37. The kit of claim 36, wherein compartment C comprises a peroxide, a persulfate, a percarbonate, or a combination thereof.

38. 38. The kit of any one of claims 34 to 37, wherein the reducing agent is selected from monohydroxyacetone, dihydroxyacetone, 3-hydroxy-2-butanone, 2-hydroxycyclohexan-1-one, glycolaldehyde, 2-hydroxy-1,2-diphenylethan-1-one, 1,5-dihydroxy-pentan-2-one, 2,3-dihydroxy-acrylaldehyde, 2,3-dihydroxy-cyclopentan-1-one, or a combination thereof.

39. Solubilized Pigment Violet 19 according to formula (I): Solubilized Pigment Red 122 according to formula (II): Solubilized Pigment Red 194 according to formula (III): Solubilized Pigment Orange 43 according to formula (IV): Solubilized tetraazaviolanthrone-trans-black according to formula (V): Solubilized tetraazaviolanthrone-cis-black according to formula (VI): Solubilized perylene-amidine-trans-blue according to formula (VII): Solubilized perylene-amidine-cis-blue according to formula (VIII): Solubilized naphthalene-amidine-trans-blue according to formula (IX): Solubilized naphthalene-amidine-cis-blue according to formula (X): Leuco vat dye sulfate ester selected from:

40. 40. Use of the leuco vat dye sulfate ester according to claim 39 in a vat dyeing process.

41. 40. Use of the leuco vat dye sulfate ester of claim 39 for coloring keratin substrates.

42. 40. Use of the leuco vat dye sulfate ester of claim 39 for coloring mammalian hair.

43. 43. The use according to claim 42, wherein the mammalian hair is human scalp hair.

44. A substrate having the leuco vat dye sulfate ester according to claim 39 adsorbed thereon.

45. 45. The substrate of claim 44, wherein the substrate is a fiber.

46. 46. ​​The substrate of claim 44 or 45, wherein the substrate is a keratin substrate.

47. 46. ​​The substrate of claim 44 or 45, wherein the substrate is a cellulosic substrate.

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