Hair dye base compositions comprising improved basifying agents, multi-compartment kits comprising same and methods of dyeing hair using same

Abstract

Disclosed is a hair dye base composition comprising an improved basifying agent, which improvement is embodied in the overall reduction of ammonia compounds, thereby advantageously minimizing the problems associated with ammonia compounds. The composition provides a satisfactory hair dyeing covering power without malodors or damage to the scalp that are typically caused by ammonia compounds, while being free of ingredients known to cause skin damage problems, such as ethoxylated compounds, PEG and derivatives thereof, and silicones, since the composition contains a high percentage of natural compounds. Therefore, the composition of the present invention is significantly healthier for customers / consumers and hairstylists using the composition, while maintaining high performance of hair dyeing. Also disclosed are multi-compartment kits comprising the compositions, dyes and oxidizing components, as well as their use in permanent hair dyeing. Also disclosed is a process for producing the hair dye base composition, and a hair dyeing method comprising applying the composition to the hair.

Description

[0001] Invention Field This invention relates to a hair dye base composition comprising an improved alkalizing agent, the improvement being reflected in the overall reduction of ammonia compounds, thereby advantageously minimizing problems associated with ammonia compounds. In fact, the composition provides satisfactory color hair coverage, without the unpleasant odor or scalp damage typically caused by ammonia compounds, while being free of monoethanolamine and other ingredients known to cause skin damage problems, such as ethoxylated compounds, PEG and its derivatives, and silicones, because the composition contains a high percentage of natural compounds.

[0002] Therefore, the compositions of the present invention are significantly healthier for customers / consumers and hairstylists using the compositions, while maintaining the high performance of hair coloring.

[0003] The present invention also relates to a multi-compartment kit containing the composition, a process for producing the hair dye base composition, and a hair dyeing method including applying the composition to hair. Background of the Invention Hair dyes are designed to give hair a color different from its natural color. Based on the duration of the color on the hair, dyes can be categorized as follows: permanent dyes (which last for more than three months), semi-permanent dyes (which last for about one and a half months), gradation dyes (which involve multiple applications to achieve the desired result), and final temporary dyes (which last for several washes).

[0005] In particular, with regard to permanent dyes, it is known that dyes produce the desired color by applying chemicals, namely colorants or their precursors that react with each other and especially with hair, to produce colored polymers: this reaction is called oxidative coupling between a primary intermediate colorant (e.g., p-phenylenediamine and p-aminophenol) and a secondary intermediate colorant (e.g., 1-naphthol, m-diamine, m-aminophenol, resorcinol, and pyrazolone), which is typically carried out in an aqueous solution containing an oxidizing agent (e.g., hydrogen peroxide).

[0006] One advantage of permanent hair dyes is their good coverage for gray hair and wide color range, while a disadvantage is the potential and frequent allergic reactions they can cause. In fact, the percentage of coloring substances in permanent hair dyes is usually no more than 6% to avoid product toxicity.

[0007] Permanent dyes are therefore oxidative dyes, formed in situ by oxidative coupling of a substance defined as a primary intermediate or oxidizing agent with a substance called a coupling agent or secondary intermediate in the presence of an oxidizing agent. Oxidative coloring methods include directly applying the dye or its precursor, or mixing the primary intermediate and coupling agent with an aqueous solution of hydrogen peroxide as an oxidizing agent, then leaving the mixture on the fiber for a defined period of time, and subsequently removing the mixture by rinsing after the fiber has been colored.

[0008] The components of suitable oxidative dyes that are applied to hair and come into contact with the scalp must meet very strict requirements.

[0009] First, the dye must provide sufficient color strength in the desired hue. Furthermore, this color must resist external factors such as adverse weather conditions, frequent shampooing, styling, and sweating. From a toxicological and dermatological perspective, the dye must also meet requirements and must not cause allergies.

[0010] The main components of permanent oxidative dyes are coloring substances, the aforementioned coupling agents and oxidizing agents, and substances used to maintain an alkaline pH, such as ammonia or monoethanolamine, also known as alkalizing substances.

[0011] Regarding substances used to maintain an alkaline pH, A. D. Bailey et al., 2014 [“ Comparison of damage to human hair fibers caused by monoethanolamine and ammonia based hair colorants[Journal of Cosmetic Science 65(1):1-9] reported (see abstract) "The number of Grade 3 hair dye products using 2-aminoethanol (monoethanolamine (MEA)) instead of ammonia is increasing. There is some anecdotal evidence that higher levels of MEA are more damaging and irritating to hair than ammonia (in the form of ammonium hydroxide), a typical alkalizing agent at equivalent levels. Our interest is in understanding the relative hair damage of the two alkalizing agents from a more quantitative perspective, particularly the upper limit of MEA use on the scalp. Limiting studies of oxidative hair damage to increases in cysteine ​​content (from cystine oxidation) may underestimate the extent of overall damage. Therefore, we supplemented our studies with Fourier transform infrared (FTIR) measurements of cysteine ​​levels with scanning electron microscopy (SEM) micrographs to visualize cuticle damage and protein loss, thus understanding that damage is not only caused by oxidative damage but also by other damaging pathways, such as the reaction of more nucleophilic (than ammonia) MEA with hair proteins." In fact, all methods show increased damage from MEA-based formulations, up to 85% in the most extreme cases compared to ammonia. Therefore, if the odor of ammonia is a concern, a better approach would be to minimize the volatility of ammonia in a given base material rather than replacing it with a high concentration of a potentially more damaging alkalizing agent such as MEA. Therefore, the object of the present invention is to provide a further improved hair dye base that is as effective as, or even more effective than, the aforementioned products of the prior art, while overcoming the limitations of the aforementioned products, particularly in terms of alkalizing substances. Invention Overview As described in this invention, the above objectives are achieved by a hair dye base composition containing an improved alkalizing agent.

[0013] In particular, the improved alkalizing agent allows the composition to minimize problems associated with ammonia compounds, such as odor or scalp damage typically caused by ammonia compounds, while providing satisfactory hair color coverage and minimizing fiber damage compared to commercial or conventional hair dye compositions; at the same time, the composition does not contain ingredients known to cause skin damage problems, such as ethoxylated compounds, PEG and its derivatives, and silicones, because the composition contains a high percentage of natural compounds.

[0014] The hair dye base composition of the present invention is also quite durable and wash-resistant / fading-resistant.

[0015] In another aspect, the present invention also relates to a process for producing the hair dye base composition.

[0016] In another aspect, the present invention also relates to a hair dyeing method comprising applying the composition to hair.

[0017] In another aspect, the present invention relates to a multi-compartment kit for hair dyeing, the kit comprising a first compartment A containing a hair dye base composition and a dye, and a second compartment B containing an oxidizing component.

[0018] In another aspect, the present invention relates to the use of hair dye base compositions for permanent hair dyeing. Brief description of the attached diagram The features and advantages of the present invention will become apparent from the following detailed description, illustrative and non-limiting working embodiments, and the accompanying drawings, in which: Figure 1A and Figure 1B The results of a post-wash color retention test performed on locks of yak hair (*) as described in Example 6 are shown, and in particular: Figure 1A The results of a color retention test after 10 wash cycles with a standard hair dye shampoo are shown, in which hair strands colored with Nuance 7, Nuance 7.4, or Nuance 6.5 in the hair dye base composition of the present invention (hereinafter referred to as "Coloro") are compared with hair strands colored with Nuance 7, Nuance 7.4, or Nuance 6.5 in a comparative monoethanolamine-based hair dye composition (hereinafter referred to as "Benchmark MEA") and hair strands colored with Nuance 7, Nuance 7.4, or Nuance 6.5 in a comparative ammonia-based hair dye composition (hereinafter referred to as "Benchmark NH3"); and Figure 1B The results of a color retention test after 10 washing cycles with a standard fortified shampoo (pH 8) are shown, in which hair strands colored with "Coloro" are compared with hair strands colored with "reference MEA" and hair strands colored with "reference NH3". Figure 2 The results of bleaching dyed hair using a bleaching agent product, as shown in Example 7, on yak hair bundles, are compared with those of hair bundles initially bleached, wherein the bleaching of hair bundles previously colored with "Coloro" is compared with that of hair bundles previously colored with "reference MEA" and hair bundles previously colored with "reference NH3" under two different conditions, namely after non-heat straightening (A) and after heat straightening (B). Figure 3 It was tested in Example 7 and Figure 2 Images of samples depicted graphically; Figure 4The results of lightening dyed hair by applying an additional dye (i.e., Nuance 10) on yak hair bundles, as shown in Example 8, are illustrated. Under two different conditions, namely after non-heat straightening (A) and after heat straightening (B), the lightening of dyed hair bundles further colored with "Coloro" (i.e., the hair dye base composition of the present invention + Nuance 10) is compared with the lightening of dyed hair bundles further colored with "reference MEA" (i.e., the comparative MEA-based hair dye composition + Nuance 10) and the lightening of dyed hair bundles further colored with "reference NH3" (i.e., the comparative NH3-based hair dye composition + Nuance 10). Figure 5 It was tested in Example 8 and Figure 4 Images of samples depicted graphically; Figure 6A Figure 6B and Figure 6C To illustrate the color coverage results after applying dye to decolorized yak hair bundles as performed in Example 9, wherein a first decolorization step is performed on the initial hair bundle, and then a second decolorization step is performed only at the ends of the hair; specifically, the dye is Nuance 7 in Figure 6A. Figure 6B Nuance 6 and Figure 6C Nuance 5; for each nuance, three different hair dye base compositions, “Coloro”, “Benchmark MEA”, and “Benchmark NH3”, were tested.

[0020] (*) Yak belly hair is currently widely used as a cheap alternative to human hair in the development of hair dyes because its chemical composition is very similar to that of human hair in Raman spectroscopy. The lack of melanin in yak belly hair also leads to a strong reduction in fluorescence in Raman measurements, which is beneficial for studying the effectiveness of hair dyes. Invention Details Therefore, the present invention relates to a hair dye base composition comprising an alkalizing agent comprising 0.01 wt% to 10.00 wt% of dimethylglucosamine and 0.01 wt% to 2.00 wt% of ammonia based on the weight of the composition, and is free of monoethanolamine.

[0022] Surprisingly, it was found that when the hair dye base is alkalized in the presence of dimethylglucosamine, the use of monoethanolamine can be advantageously avoided, while simultaneously reducing the total ammonia content to no more than 2.00 wt%. This yields a hair dye base composition that is appropriately stable at an alkaline pH and advantageously minimizes the release of unpleasant odors derived from ammonia, while still benefiting from the presence of ammonia in the composition.

[0023] Dimethylglucosamine (CAS No.: 76326-99-3), also known as N,N-dimethylglucosamine, 1-deoxy-1-(dimethylamino)-D-glucitol, (2R,3R,4R,5S)-6-(dimethylamino)hexane-1,2,3,4,5-pentanol, (2R,3R,4R,5S)-6-(dimethylamino)hexane-1,2,3,4,5-pentanol, or methylglucosamine, is a compound commonly used as a reagent in the synthesis of N,N-dimethyl-N-alkyl-D-glucosamine bromide (which exhibits antimicrobial activity). Therefore, the direct use of dimethylglucosamine in hair dye products is unprecedented, especially regarding its role as an effective substitute for monoethanolamine and in supplementing ammonia.

[0024] Preferably, the weight ratio of dimethylglucosamine to ammonia is 1:1 to 1:5, more preferably 1:1.1 to 1:3.5, and even more preferably 1:1.2 to 1:2.5.

[0025] More preferably, the alkalizing agent of the composition of the present invention comprises 0.05 wt% to 5.00 wt% of dimethylglucosamine and 0.30 wt% to 1.90 wt% of ammonia based on the weight of the composition. Even more preferably, the alkalizing agent of the composition of the present invention comprises 0.50 wt% to 2.00 wt% of dimethylglucosamine and 0.50 wt% to 1.85 wt% of ammonia based on the weight of the composition.

[0026] In a preferred embodiment, the alkalizing agent further comprises ammonium bicarbonate.

[0027] More preferably, the alkalizing agent comprises 0.01 wt% to 2.50 wt% of ammonium bicarbonate based on the weight of the composition. Even more preferably, the alkalizing agent comprises 0.10 wt% to 2.00 wt% of ammonium bicarbonate based on the weight of the composition.

[0028] In a particularly preferred embodiment, the alkalizing agent comprises a mixture of 0.95 wt% to 1.90 wt% dimethylglucosamine, 1.00 wt% to 1.80 wt% ammonia and 0.50 wt% to 1.50 wt% ammonium bicarbonate, based on the weight of the composition.

[0029] In the most preferred embodiment, the alkalizing agent is essentially a mixture of dimethylglucosamine, ammonia, and ammonium bicarbonate. It has been observed that when subsequently colored with the composition of the present invention, the mixture of at least these three compounds in the composition allows for improved lightening of the dyed hair.

[0030] In other preferred embodiments, the alkalizing agent further comprises aminomethylpropanol, ammonium bicarbonate, or a mixture thereof.

[0031] More preferably, the alkalizing agent comprises a mixture of 0.01 wt% to 3.00 wt% aminomethylpropanol and 0.01 wt% to 2.50 wt% ammonium bicarbonate based on the weight of the composition. Even more preferably, the alkalizing agent comprises a mixture of 0.10 wt% to 2.90 wt% aminomethylpropanol and 0.10 wt% to 2.00 wt% ammonium bicarbonate based on the weight of the composition.

[0032] In a particularly preferred embodiment, the alkalizing agent comprises a mixture of 0.95 wt% to 1.90 wt% dimethylglucosamine, 1.00 wt% to 1.80 wt% ammonia, 0.50 wt% to 2.85 wt% aminomethylpropanol and 0.50 wt% to 1.50 wt% ammonium bicarbonate, based on the weight of the composition.

[0033] In the most preferred embodiment, the alkalizing agent comprises a mixture of dimethylglucosamine, aminomethylpropanol, ammonia, and ammonium bicarbonate. It has been observed that when subsequently colored with the composition of the present invention, the mixture of these four compounds in the composition allows for further improvement in the lightening effect of the dyed hair.

[0034] The hair dye base composition of the present invention further comprises water, at least one major intermediate, at least one minor intermediate, at least one antioxidant, a lipophilic matrix, and a hydrophilic matrix.

[0035] The hair dye base composition of the present invention is also advantageously free of ethoxylated compounds, polyethylene glycol, sulfates, and silicones. In this respect, satisfactory and high-performance compositions have been achieved by using alternative ingredients with natural sources, such as coconut oil, propylene glycol, sodium cocoyl glutamate, and olive oil polyglycerol-6 esters.

[0036] The hair dye base composition of the present invention further comprises at least one major intermediate, which is preferably selected from p-phenylenediamine, toluene-2,5-diamine sulfate, p-aminophenol, n-bis(2-hydroxyethyl)-p-phenylenediamine, 4-amino-m-cresol, p-methylaminophenol sulfate, 1-hydroxyethyl-4,5-diaminopyrazole sulfate, and mixtures thereof.

[0037] More preferably, the at least one major intermediate is selected from toluene-2,5-diamine sulfate, p-aminophenol, p-methylaminophenol sulfate, and mixtures thereof.

[0038] In a preferred embodiment, the hair dye base composition of the present invention comprises 0.01 wt% to 5.00 wt% of the at least one major intermediate based on the weight of the composition.

[0039] In a more preferred embodiment, the hair dye base composition of the present invention comprises 0.02 wt% to 3.00 wt% of the at least one major intermediate based on the weight of the composition.

[0040] The hair dye base composition of the present invention further comprises at least one minor intermediate, which is preferably selected from resorcinol, m-aminophenol, 1-naphthol, 4-chlororesorcinol, 4-amino-2-hydroxytoluene, 2-methylresorcinol, phenylmethylpyrazolone, 2-amino-4-hydroxyethylaminoanisole sulfate, 2-amino-3-hydroxypyridine, 2,4-diaminophenoxyethanol sulfate, 2-methyl-5-hydroxyethylaminophenol, 6-amino-m-cresol, 5-amino-6-chloro-o-cresol, 2-amino-6-chloro-4-nitrophenol, 2,6-dihydroxyethylaminotoluene, hydroxyethyl-3,4-methylenedioxyaniline hydrochloride, 2,4-diaminophenoxyethanol hydrochloride, and mixtures thereof.

[0041] More preferably, the at least one minor intermediate is selected from m-aminophenol, 4-chlororesorcinol, 2-methylresorcinol, phenylmethylpyrazolone, 2,4-diaminophenoxyethanol hydrochloride, and mixtures thereof.

[0042] In a preferred embodiment, the hair dye base composition of the present invention comprises 0.01 wt% to 5.00 wt% of the at least one minor intermediate based on the weight of the composition.

[0043] In a more preferred embodiment, the hair dye base composition of the present invention comprises 0.05 wt% to 4.00 wt% of the at least one minor intermediate based on the weight of the composition.

[0044] In other embodiments, the weight ratio between the at least one primary intermediate and the at least one secondary intermediate is 1:1 to 1:3.

[0045] The compositions according to the invention may optionally comprise one or more synthetic or natural direct dyes selected from anionic, cationic, and nonionic substances and mixtures thereof. Examples of suitable direct dyes may include Basic Red 51, Basic Orange 31, and Basic Yellow 87. Exemplary natural direct dyes may be lawsone, juglone, alizarin, purpuric, indigo, indigo red, curcumin, and mixtures thereof. Extracts or decoctions containing these natural hair dyes, such as henna-based extracts, may also be used.

[0046] Preferably, the hair dye base composition of the present invention further comprises at least one antioxidant, which is preferably selected from isoascorbic acid, sodium dithionite, sodium sulfite, ascorbic acid and mixtures thereof.

[0047] Preferably, the hair dye base composition of the present invention further comprises a lipophilic matrix, which preferably includes sorbitan stearate, oleic acid, petrolatum, hydrogenated castor oil, carnauba wax (Copernicia cerifera cera), castor seed oil (ricinus communis seed oil), oleth-4 phosphate, oleyl phosphate, lauryl ether-3, cetearyl oliveate, sorbitan oliveate, cetearyl alcohol, ceteareth-20, polysorbate 60, dicaprylyl ether, stearic acid, glyceryl stearate, oleyl alcohol, sorbitan oleate, palmitic acid, olive oil polyglycerol-6 esters, glyceryl isostearate, and beeswax. (alba), BHT, crambe abyssinica seed oil, coconut oil (cocos nucifera oil) and mixtures thereof.

[0048] More preferably, the lipophilic matrix includes sorbitan stearate, oleic acid, hydrogenated castor oil, carnauba wax, castor seed oil, dioctyl ether, sorbitan oleate, cetearyl alcohol, hydrogenated castor oil, stearic acid, palmitic acid, olive oil polyglycerol-6 esters, glyceryl isostearate, coconut oil, and mixtures thereof.

[0049] In a preferred embodiment, the hair dye base composition of the present invention comprises 15 wt% to 60 wt% of the lipophilic matrix, more preferably 25 wt% to 45 wt%, and even more preferably 30 wt% to 40 wt% of the lipophilic matrix based on the weight of the composition.

[0050] Preferably, the hair dye base composition of the present invention further comprises a hydrophilic matrix, which preferably includes betaine, etidronic acid, propylene glycol, disodium EDTA, trisodium dicarboxymethylalanine, sodium cocoyl glutamate, sodium stearoyl glutamate, cocamidopropyl betaine, and mixtures thereof.

[0051] In a preferred embodiment, the hair dye base composition of the present invention comprises 10 wt% to 30 wt% of the hydrophilic matrix based on the weight of the composition, more preferably 15 wt% to 20 wt% of the hydrophilic matrix.

[0052] In other embodiments, the weight ratio between the lipophilic matrix and the hydrophilic matrix is ​​3:1 to 1:1, more preferably about 2:1.

[0053] Optionally, the hair dye base composition of the present invention may further include a fragrance, preferably 0.50 wt% to 2.50 wt% of the fragrance based on the weight of the composition.

[0054] Other and optional ingredients may include vegetable oils, protein hydrolysates, plant extracts, organic and inorganic pigments, and mixtures thereof.

[0055] In other preferred embodiments, the present invention relates to a hair dye base composition comprising an alkalizing agent, said alkalizing agent being substantially composed of 0.05 wt% to 3.00 wt% dimethylglucosamine, 0.01 wt% to 2.00 wt% ammonia, and ammonium bicarbonate based on the weight of the composition, and free of monoethanolamine. The term "substantially composed of" means that the listed ingredients are the only active substances in the alkalizing agent with alkalizing properties, and the remaining optional ingredients are solvents, such as water, and are merely co-formulant components that do not affect pH.

[0056] In another preferred embodiment, the present invention relates to a hair dye base composition comprising an alkalizing agent, said alkalizing agent being composed of water, 0.05 wt% to 3.00 wt% dimethylglucosamine, 0.01 wt% to 2.00 wt% ammonia, and ammonium bicarbonate, based on the weight of the composition, and is free of monoethanolamine.

[0057] In another preferred embodiment, the present invention relates to a hair dye base composition comprising an alkalizing agent, said alkalizing agent being substantially composed of 0.05 wt% to 3.00 wt% dimethylglucosamine, 0.01 wt% to 2.00 wt% ammonia, aminomethylpropanol, and ammonium bicarbonate based on the weight of the composition, and free of monoethanolamine. The term "substantially composed of" means that the listed ingredients are the only active substances in the alkalizing agent with alkalizing properties, and the remaining optional ingredients are solvents, such as water, and are merely auxiliary components that do not affect pH.

[0058] In another preferred embodiment, the present invention relates to a hair dye base composition comprising an alkalizing agent, said alkalizing agent being composed of water, 0.05 wt% to 3.00 wt% dimethylglucosamine, 0.01 wt% to 2.00 wt% ammonia, aminomethylpropanol and ammonium bicarbonate, based on the weight of the composition, and is free of monoethanolamine.

[0059] It should be understood that all aspects deemed preferred and advantageous for the compositions of the present invention are also considered to be similarly preferred and advantageous for the compositions of the present invention as indicated by the terms "consistently composed of" and "composed of".

[0060] In another aspect, the present invention also relates to a multi-compartment kit for hair dyeing, the kit comprising a first compartment A) containing a hair dye base composition and dye as described above, and a second compartment B containing an oxidizing component.

[0061] For the purposes of this invention, the term "dye" refers to a coloring agent or precursor used for hair, and is generally associated with numbers. Tone height numbers are unique codes that explain the many different colors and shades of hair dye. These numbers are the same worldwide and have the structure "xy". The first number "x", the number to the left of the dot, is the tone height number. The larger the number, the lighter the color. The tone height range is from 1 (black) to 10 (light gold). The second number "y", the number to the right of the dot, represents the color naunce. For example, in 7.1, 1 represents ash. This means it is a matte, cool-toned dark brown. Some colors have a third number "z", which refers to the hue of the color. For example, in 4.13, 1 represents ash, and 3 represents gold.

[0062] The dye should be mixed with the oxidant in a certain percentage ratio, for example from 1:1 to 1:10, preferably from 1:1 to 1:4.

[0063] The oxidizing component of the kit should contain at least one oxidizing agent, preferably selected from peroxides, persulfates, percarbonates, alkali metal bromates, ferricyanides, peroxygenated salts, and mixtures thereof.

[0064] In a preferred embodiment, the oxidant is hydrogen peroxide, and its volume concentration is preferably from 1 volume to 40 volumes.

[0065] The oxidizing components of the kit may also contain solvents (such as water or organic solvents or mixtures thereof), rheology or viscosity additives, chelating agents, surfactants, pH adjusters, preservatives and / or fragrances.

[0066] Oxidized components can be in the form of powder, gel, liquid, foam, lotion, cream, mousse or emulsion.

[0067] In another aspect, the present invention also relates to a process for producing the hair dye base composition. Specifically, the process includes the following steps: a) A hydrophilic phase is prepared by mixing the hydrophilic component and the alkalizing agent of the present invention at 70°C to 75°C; b) A lipophilic phase was prepared by mixing lipophilic components at 70°C to 75°C; c) Add the lipophilic phase to the hydrophilic phase while stirring until a homogeneous emulsion is obtained; and d) The emulsion is kept stirred for several minutes and then cooled to below 50°C to obtain the hair dye base composition.

[0068] In a preferred embodiment, the alkalizing agent further comprises ammonium bicarbonate, which is set aside and added after step d), and then the temperature of the composition is raised to room temperature.

[0069] In a more preferred embodiment, the alkalizing agent further comprises aminomethylpropanol, ammonium bicarbonate, or a mixture thereof, which is set aside and added after step d), and then the temperature of the composition is raised to room temperature.

[0070] In another aspect, the present invention relates to the use of hair dye base compositions as described above or multi-compartment kits as described above for permanent hair dyeing.

[0071] Furthermore, the present invention also relates to a hair dyeing method, comprising applying the composition to hair. Specifically, the method includes the following steps: i) Mix the hair dye base composition of the present invention with the dye and oxidant until a uniform cream is obtained; ii) Apply the cream to the hair; and iii) Rinse with water and wash with post-dye shampoo.

[0072] Preferably, in step ii), the cream is left on the hair for 20 to 50 minutes before rinsing with water, the duration depending on the desired coloring / lightening effect.

[0073] It should be understood that all aspects deemed preferred and advantageous for the compositions of the present invention are also considered to be similarly preferred and advantageous for the kit and the use and method of application of the compositions.

[0074] It should also be understood that all combinations of preferred and advantageous features of the composition, kit, use and method are considered to be described herein.

[0075] Working embodiments of the invention provided for illustrative purposes are reported below.

[0076] Example Example 1 Prepare the following hair dye base composition: In this case, the actual concentration of dimethylglucosamine is 1 wt% based on the weight of the composition, while the actual concentration of ammonia is 1.35 wt%, which is very low.

[0077] The first step is to prepare the hydrophilic phase. Mix all the components, heat to 70°C to 75°C, and add the oxidation intermediate, alkalizing agent (except ammonium bicarbonate), and antioxidant.

[0078] In the second step, the lipophilic phase is heated to 70°C to 75°C and added to the hydrophilic phase with stirring to form an emulsion. The mixture is kept stirred for several minutes and then cooled to below 50°C. Ammonium bicarbonate, the active ingredient, and the fragrance are added, and the composition is allowed to reach room temperature.

[0079] Example 2 Prepare the following hair dye base composition: In this case, based on the weight of the composition, the actual concentration of dimethylglucosamine was 1.25 wt%, and the actual concentration of ammonia was 1.20 wt%, which is even lower than in Example 1.

[0080] The preparation steps are the same as in Example 1.

[0081] Examples 3 to 5 The composition of Example 1 was prepared by changing only the alkalizing agent (and the total content of water as a balance to 100 wt%), while keeping other components unchanged.

[0082] Use the following alkalizing agents: The value in parentheses represents the actual concentration of the component in the corresponding composition.

[0083] The composition of Example 3 according to the present invention comprises dimethylglucosamine and ammonia.

[0084] In the comparative composition of Example 4, ammonia was used as the sole alkalizing agent.

[0085] In the comparative composition of Example 5, monoethanolamine was used instead of ammonia as the sole alkalizing agent.

[0086] In the following text, the composition of Example 3 will be referred to as "Coloro", the comparative composition of Example 4 will be referred to as "reference NH3", and the comparative composition of Example 5 will be referred to as "reference MEA".

[0087] Example 6 - Color retention test after washing The total number of 90 yak hair bundles were divided into three groups and then dyed using the following method: Group I: Hair strands were colored in the hair dye base composition (“Coloro”) of Example 3 using Nuance 7, Nuance 7.4, or Nuance 6.5. Group II: Hair strands were colored with Nuance 7, Nuance 7.4, or Nuance 6.5 in the comparative monoethanolamine-based hair dye composition (“Standard NH3”) of Example 4. Group III: Hair strands were colored with Nuance 7, Nuance 7.4, or Nuance 6.5 in the comparative ammonia-based hair dye composition of Example 5 (referred to as "Baseline MEA"). Each group of hair strands dyed in this way was further subdivided into three subgroups to evaluate color retention after shampooing, as shown below: CTRL subgroup: Control subgroup, unwashed Subgroup A: Hair strands washed 10 times with standard post-dye shampoo. Subgroup B: Hair strands subjected to 10 washing cycles with a intensive treatment shampoo (pH 8). Figure 1A and Figure 1B The results of the color retention test after washing, as reported above, are shown.

[0088] Specifically, Figure 1A The results of the color retention test for subgroup A are shown, in which hair strands from group I (“Coloro”) have been shown, as measured and visually by a colorimeter (i.e., a Konica Minolta CM-3600A spectrophotometer), to have better color retention than hair strands from groups II (“Reference NH3”) and III (“Reference MEA”) relative to the corresponding CTRL subgroup.

[0089] Figure 1B The results of the color retention test for subgroup B are shown, in which hair strands from group I (“Coloro”) are again shown to retain color better than hair strands from groups II (“Base NH3”) and III (“Base MEA”) relative to the corresponding CTRL subgroups, as measured by a colorimeter and visually.

[0090] These results confirm that hair dye base compositions containing the alkalizing agent of the present invention allow for satisfactory and long-lasting dye retention on hair, with improved durability compared to comparative compositions.

[0091] Example 7 - Decolorizing dyed hair using a decolorizing agent product. The initial total of 90 decolorized yak hair bundles were divided into three groups, and then dyed with Nuance 10 in the following groups: Group I: "Coloro" Group II: "Standard NH3" Group III: Benchmark MEA exist Figure 3 The middle image shows the initially bleached yak hair bundles as "initial bleached hair bundles", while the lower image shows the dyed hair bundles of the above three groups as "dyed hair bundles".

[0092] Then, a standard bleaching agent was used to perform a double-cycle bleaching process on all three groups of dyed hair strands. Afterward, each group of hair strands was subdivided into two subgroups: Subgroup A: Hair strands subjected to non-heated hair straightening (i.e., room temperature). Subgroup B: Hair strands subjected to heat-induced hair straightening The straightened hair strands obtained are Figure 3 The middle image shows the right image.

[0093] Figure 2 The figure shows the results of bleaching dyed hair with a bleaching agent product relative to the initial bleaching of the hair strands. The double bleaching of the hair strands in the "Coloro" group is compared with the double bleaching of the hair strands in the "Baseline MEA" group and the "Baseline NH3" group under two different conditions, namely after non-heat straightening (A) and after heat straightening (B).

[0094] Similarly, hair strands treated with Coloro, as measured by a colorimeter and visually evaluated, showed better results in minimizing the increment between the initial and double-decolorized hair strands. In fact, in this case, the lower the difference (Δ) between the initial decolorized hair strand and the final double-decolorized hair strand, the better the performance results obtained.

[0095] Example 8 - Lightening dyed hair by applying additional dye The initial total of 90 yak hair bundles, dyed with Nuance 6, were divided into three groups, and then lightened by applying another dye (Nuance 10) to the following groups: Group I: "Coloro" Group II: "Standard NH3" Group III: Benchmark MEA exist Figure 5 The middle image shows the initial colored yak hair bundles as "colored hair," while the three groups of lighter-colored hair bundles mentioned above are shown, and each group is further subdivided into two subgroups: Subgroup A: Hair strands subjected to non-heated hair straightening (i.e., room temperature). Subgroup B: Hair strands subjected to heat-induced hair straightening The purpose of this test was to investigate the possibility of lightening the initial dark brown (Nuance 6) with further coloring steps involving Nuance 10.

[0096] like Figure 4 The results reported in the study involved lightening dyed hair strands by applying another dye (i.e., Nuance 10). The lightening was compared between two different conditions: after non-heat-straightening (A) and after heat-straightening (B), with the lightening achieved by further coloring the dyed hair strands with "Coloro" (i.e., the hair dye base composition of the present invention + Nuance 10), with the lightening achieved by further coloring the dyed hair strands with "reference MEA" (i.e., a comparative MEA-based hair dye composition + Nuance 10), and with the lightening achieved by further coloring the dyed hair strands with "reference NH3" (i.e., a comparative NH3-based hair dye composition + Nuance 10).

[0097] In this case, the higher the difference (Δ) between the initially colored hair strand and the final lightened hair strand, the better the lightening result. Similarly, hair strands treated with Coloro showed better performance under both straightening conditions A and B compared to hair strands treated with reference MEA and reference NH3.

[0098] Example 9 - Color hiding power of bleached hair after dye application The initial total of 90 yak hair bundles were subjected to the first bleaching step, and then the second bleaching step was performed only at the ends, as shown in Figures 6A to 6B. Figure 6C As shown, the hair strand on the left is labeled "initially partially bleached hair" to emphasize that the same hair strand underwent two different bleaching processes.

[0099] Then each initial hair strand is treated with either Nuance 7 (Figure 6A) or Nuance 6 in the following groups. Figure 6B ) or Nuance 5 ( Figure 6C ) Coloring: Group I: "Coloro" Group II: "Standard NH3" Group III: Benchmark MEA Figure 6A Figure 6B and Figure 6C This is an image showing the color-covering effect of the bleached yak hair bundles as described above after the application of dye.

[0100] The results obtained indicate that the baseline MEA provides good coloring for all Nuance hair strands that undergo single-brightening, but exhibits an unpleasant dark metallic coloring at the ends of double-brightening hair strands.

[0101] The benchmark NH3 exhibits unsatisfactory color coverage, resulting in a visually opaque appearance.

[0102] Conversely, Coloro exhibits remarkable color coverage and a pleasingly bright appearance throughout the entire length of the hair.

[0103] Examples 10-11 Example 8 was repeated, except that the composition of Example 3 was not used, but the compositions of Examples 1 and 2 were used, thus obtaining Group IV and Group V, respectively.

[0104] As stated, the purpose of this test was to investigate the possibility of lightening the initial dark brown (Nuance 6) with a further coloring step involving Nuance 10, such that the higher the difference (Δ) between the initially colored hair strand and the final lightened hair strand, the better the lightening result.

[0105] It was observed that hair strands treated with the composition of Example 1 (i.e., group IV) and hair strands treated with the composition of Example 2 (i.e., group V) showed better performance under both straightening conditions A and B, even better than hair strands treated with Coloro.

[0106] It is believed that the additional presence of aminomethylpropanol and ammonium bicarbonate in the alkalizing agent further improves the lightening effect of the composition of the present invention on dyed hair.

[0107] Example 12 Prepare the following hair dye base composition: In this case, based on the weight of the composition, the actual concentration of dimethylglucosamine is 1.25 wt%, while the actual concentration of ammonia is 1.5 wt%, which is very low.

[0108] The first step is to prepare the hydrophilic phase. Mix all the components, heat to 70°C to 75°C, and add the oxidation intermediate, alkalizing agent (except ammonium bicarbonate), and antioxidant.

[0109] In the second step, the lipophilic phase is heated to 70°C to 75°C and added to the hydrophilic phase with stirring to form an emulsion. The mixture is kept stirred for several minutes and then cooled to below 50°C. Ammonium bicarbonate, the active ingredient, and the fragrance are added, and the composition is allowed to reach room temperature.

[0110] Example 13 Prepare the following hair dye base composition: In this case, based on the weight of the composition, the actual concentration of dimethylglucosamine was 1.5 wt%, while the actual concentration of ammonia was 1.35 wt%, which is even lower than in Example 12.

[0111] The preparation steps are the same as in Example 12.

[0112] Examples 14-16 The composition of Example 12 was prepared by changing only the alkalizing agent (and the total content of water as a balance to 100 wt%), while keeping the other components unchanged.

[0113] Use the following alkalizing agents: The value in parentheses represents the actual concentration of the component in the corresponding composition.

[0114] The composition of Example 14 of the present invention comprises dimethylglucosamine and ammonia, as well as ammonium bicarbonate.

[0115] In the comparative composition of Example 15, ammonia was used as the sole alkalizing agent.

[0116] In the comparative composition of Example 16, monoethanolamine was used instead of ammonia as the sole alkalizing agent.

[0117] In the same case, the composition of Example 14 according to the preferred embodiment of the invention shows better performance under both straightening conditions A and B, due to the additional presence of ammonium bicarbonate in the alkalizing agent, which further improves the lightening effect on dyed hair.

[0118] For the compositions of Comparative Examples 15 and 16, the shallowing effect was found to be unsatisfactory.

Claims

1. A hair dye base composition comprising an alkalizing agent, said alkalizing agent comprising 0.01 wt% to 10.00 wt% of dimethylglucosamine and 0.01 wt% to 2.00 wt% of ammonia based on the weight of the composition, and free of monoethanolamine.

2. The composition according to claim 1, wherein the weight ratio of dimethylglucosamine to ammonia is 1:1 to 1:5, preferably 1:1.1 to 1:3.5, more preferably 1:1.2 to 1:2.

5.

3. The composition according to claim 1 or 2, wherein the alkalizing agent comprises 0.05 wt% to 5.00 wt% of dimethylglucosamine and 0.30 wt% to 1.90 wt% of ammonia based on the weight of the composition, preferably 0.50 wt% to 2.00 wt% of dimethylglucosamine and 0.50 wt% to 1.85 wt% of ammonia.

4. The composition according to any one of claims 1 to 3, wherein the alkalizing agent further comprises aminomethylpropanol, ammonium bicarbonate, or a mixture thereof.

5. The composition according to claim 4, wherein the alkalizing agent further comprises, based on the weight of the composition, a mixture of 0.01 wt% to 3.00 wt% aminomethylpropanol and 0.01 wt% to 2.50 wt% ammonium bicarbonate, preferably a mixture of 0.10 wt% to 2.90 wt% aminomethylpropanol and 0.10 wt% to 2.00 wt% ammonium bicarbonate.

6. The composition according to claim 4 or 5, wherein the alkalizing agent comprises, based on the weight of the composition, a mixture of 0.95 wt% to 1.90 wt% dimethylglucosamine, 1.00 wt% to 1.80 wt% ammonia, 0.50 wt% to 2.85 wt% aminomethylpropanol and 0.50 wt% to 1.50 wt% ammonium bicarbonate.

7. The composition according to any one of claims 4 to 6, wherein the alkalizing agent is composed of a mixture of dimethylglucosamine, ammonia, aminomethylpropanol and ammonium bicarbonate.

8. The composition according to any one of claims 1 to 7, wherein the composition is free of ethoxylated compounds, polyethylene glycol, alkylbenzene sulfonates / alkylbenzene sulfonates and silicones.

9. The composition according to any one of claims 1 to 8, wherein the composition further comprises water, at least one major intermediate, at least one minor intermediate, at least one antioxidant, a lipophilic matrix, and a hydrophilic matrix.

10. A multi-compartment kit for hair dyeing, the kit comprising a first compartment A) containing a hair dye base composition and dye as described in any one of claims 1 to 9, and a second compartment B containing an oxidizing component.

11. The multi-compartment kit of claim 10, wherein the oxidizing component comprises hydrogen peroxide.

12. Use of the hair dye base composition according to any one of claims 1 to 9 for permanent hair dyeing, or use of the multi-compartment kit according to claim 10 or 11 for permanent hair dyeing.

13. A hair dyeing method, comprising the following steps: i) Mix the hair dye base composition according to any one of claims 1 to 9 with the dye and oxidant until a uniform cream is obtained; ii) Apply the cream to the hair; and iii) Rinse with water and wash with post-dye shampoo.

14. The hair dyeing method according to claim 13, wherein in step ii), the cream remains on the hair for 20 to 50 minutes before rinsing with water.

15. A process for producing the hair dye base composition according to any one of claims 1 to 9, the process comprising the following steps: a) A hydrophilic phase is prepared by mixing the hydrophilic component and the alkalizing agent at 70°C to 75°C; b) A lipophilic phase was prepared by mixing lipophilic components at 70°C to 75°C; c) Add the lipophilic phase to the hydrophilic phase while stirring until a homogeneous emulsion is obtained; and d) The emulsion is kept stirred for several minutes and then cooled to below 50°C to obtain the hair dye base composition.

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