Composition for the treatment of keratinous fibers, comprising a water-soluble silicate and a water-soluble acid

Abstract

Composition for the treatment of keratinous fibers, comprising a water-soluble silicate and a water-soluble acid. The present invention relates to a composition for the treatment of keratinous fibers, preferably hair, comprising: (a) at least one water-soluble silicate; (b) at least one water-soluble acid; and (c) water, wherein the composition is in the form of an aqueous solution and has a pH value of 2 to 10. Figure for abstract: None

Description

Title of the invention: Composition for the treatment of keratinous fibers, comprising a water-soluble silicate and a water-soluble acid technical field

[0001] The present invention relates to a cosmetic composition, in particular a cosmetic composition for keratinous fibers, such as hair, comprising a water-soluble silicate and an acidic compound. STATE OF THE ART

[0002] Water-soluble silicates, such as alkali silicates, are widely used in hair coloring and bleaching products to provide a high pH as well as to chelate metal ions.

[0003] For example, document WO 2021 / 009083 discloses a process for the treatment of keratinous fibers, comprising the following successive steps: i) application to the keratinous fibers of a composition (A) comprising at least one water-soluble silicate; and ii) application to the keratinous fibers of a composition (B) comprising at least one compound (b) selected from amino acids, oligopeptides, their salts, their solvates such as hydrates, and mixtures thereof.

[0004] In the cosmetic field, particularly in the field of hair care cosmetics, there is a strong demand for cosmetic compositions for the treatment and / or care of keratinous fibers, enabling the keratinous fibers to have cosmetic effects. disclosure of the invention

[0005] An objective of the present invention is to propose a composition for the treatment of keratinous fibers which can confer on the keratinous fibers very beneficial cosmetic effects, such as better integrity, better resistance of the fibers and longer durability of the color.

[0006] The above objective of the present invention can be achieved by a composition for the treatment of keratinous fibers, preferably hair, comprising:

[0007] (a) at least one water-soluble silicate;

[0008] (b) at least one water-soluble acid; and

[0009] (c) water,

[0010] wherein the composition is in the form of an aqueous solution and has a pH value of 2 to 10.

[0011] The (a) water-soluble silicate may be selected from alkali metal or alkaline earth metal silicates and mixtures thereof, preferably from silicates of alkali metals, such as sodium silicates, potassium silicates and their mixtures, more preferably among sodium silicates.

[0012] The amount of (a) water-soluble silicate that may be present in the composition is 0.1% by weight or more, preferably 0.3% by weight or more, more preferably 0.6% by weight or more, even more preferably 0.7% by weight or more, and in particular 0.8% by weight or more; and / or may be 10% by weight or less, preferably 5% by weight or less, and more preferably 3% by weight or less, and even more preferably 2% by weight or less, relative to the total weight of the composition.

[0013] The (b) water-soluble acid may be an organic acid preferably chosen from among organic acids having one or more carboxylic acid groups and / or phosphonic groups.

[0014] The (b) water-soluble acid can be chosen from aliphatic monocarboxylic acids and hydroxy acids.

[0015] The (b) water-soluble acid may be selected from glycoxylic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, gluconic acid, phytic acid and a mixture thereof.

[0016] The amount of (b) water-soluble acid in the composition may be 0.1% by weight or more, preferably 0.2% by weight or more, more preferably 0.5% by weight or more, even more preferably 0.7% by weight or more, and in particular 1% by weight or more; and / or may be 15% by weight or less, preferably 10% by weight or less, more preferably 7% by weight or less, even more preferably 5% by weight or less, and in particular 3% by weight or less, relative to the total weight of the composition.

[0017] The pH value of the composition can range from 3 to 9, more preferably from 3 to 8, even more preferably from 3 to 6, and in particular from 4 to 6.

[0018] The amount of (c) water in the composition may be 50% by weight or more, preferably 65% ​​by weight or more, more preferably 80% by weight or more, and even more preferably 90% by weight or more; and / or may be 99.5% by weight or less, preferably 99% by weight or less, relative to the total weight of the composition.

[0019] The total quantity of components (a), (b) and (c) in the composition may be 70% by weight or more, preferably 75% by weight or more, more preferably 80% by weight or more, even more preferably 85% by weight or more, preferably 90% by weight or more, even more preferably 95% by weight or more, even more preferably 97% by weight or more, and in particular 98% by weight or more, relative to the weight total composition.

[0020] The present invention also relates to a cosmetic process for the care or conditioning of keratinous fibers, preferably hair, comprising the step of applying the composition according to the present invention to the keratinous fibers.

[0021] The present invention also relates to the use of a combination of (a) at least one water-soluble silicate and (b) at least one water-soluble acid in an aqueous solution comprising (c) water and having a pH value of 2 to 10, for the care or conditioning of keratinous fibers, such as hair. Brief description of the drawings

[0022] [Fig-1] Fig. 1 shows a schematic view of how to determine the bending angles for examples 2 and 4 to 6 and comparative example 1. Best embodiment of the invention

[0023] After diligent research, the inventors have discovered, surprisingly, that the composition according to the present invention can improve the integrity of keratin fibers, the strength of keratin fibers and the color durability of keratin fibers, and have therefore realized the invention.

[0024] Thus, one aspect of the present invention is a composition for the treatment of keratinous fibers, preferably hair, comprising:

[0025] (a) at least one water-soluble silicate;

[0026] (b) at least one water-soluble acid, and

[0027] (c) water,

[0028] wherein the composition is in the form of an aqueous solution and has a pH value of 2 to 10.

[0029] Another aspect of the present invention is a cosmetic process or use for the care and / or conditioning of keratinous fibers, preferably hair, comprising the application to the keratinous fibers of the composition according to the present invention.

[0030] The composition and process according to the present invention will each be described in detail below.

[0031] [Composition]

[0032] The composition according to the present invention is a composition for the treatment and / or care of keratinous fibers, preferably hair, comprising:

[0033] (a) at least one water-soluble silicate;

[0034] (b) at least one water-soluble acid; and

[0035] (c) water,

[0036] wherein the composition is in the form of an aqueous solution and has a value pH from 2 to 10.

[0037] The composition according to the present invention is intended for the treatment of keratinous fibers, such as hair. The term "keratinous fibers" means fibers of human or animal origin, such as hair, fur, eyelashes, eyebrows, wool, angora, cashmere, or fur. According to the present invention, the keratinous fibers are preferably human keratinous fibers, more preferably hair.

[0038] The composition according to the present invention is in the form of an aqueous solution.

[0039] The composition according to the present invention has a pH of 2 to 10, preferably of 3 to 9, and more preferably from 3 to 8, more preferably from 3 to 6, and especially from 4 to 6. The pH of the composition can be corrected to the desired value using one or more alkaline agents and / or one or more acidic agents commonly used in the field of cosmetics.

[0040] The composition according to the present invention comprises (a) at least one water-soluble silicate, (b) at least one water-soluble acid, and (c) water. Each of these components will be described in detail.

[0041] (Water-soluble silicate)

[0042] The composition according to the present invention comprises (a) at least one water-soluble silicate.

[0043] The expression "water-soluble silicate" means in this document a silicate which has a solubility in water at ordinary room temperature (25 °C) and atmospheric pressure (760 mmHg) greater than 0.5% by weight, preferably greater than 1% by weight.

[0044] The water-soluble silicate is preferably chosen from alkali metal or alkaline earth metal silicates, and mixtures thereof. More preferably, the water-soluble silicate is chosen from alkali metal silicates, such as sodium silicates and potassium silicates, and mixtures thereof. Even more preferably, the water-soluble silicate is chosen from sodium silicates. Most preferably, the water-soluble silicate is sodium metasilicate.

[0045] The water-soluble silicate(s) may be present in the composition according to the present invention in an amount of 0.1% by weight or more, preferably 0.3% by weight or more, more preferably 0.6% by weight or more, even more preferably 0.7% by weight or more, and in particular 0.8% by weight or more; and / or may be 10% by weight or less, preferably 5% by weight or less, more preferably 3% by weight or less, and even more preferably 2% by weight or less, relative to the total weight of the composition.

[0046] The water-soluble silicate(s) may be present in the composition according to the present invention in an amount of 0.1% to 10% by weight, preferably 0.3% to 5% by weight, more preferably 0.6% to 3% by weight, even more preferably 0.7% to 2% by weight, and in particular 0.8% to 2% by weight, relative to the total weight of the composition.

[0047] (Water-soluble acid)

[0048] The composition according to the present invention comprises (b) at least one water-soluble acid.

[0049] The expression "water-soluble acid" in this document indicates an acid having a solubility in water at ordinary room temperature (25 °C) and atmospheric pressure (760 mmHg) greater than 0.5% by weight, preferably greater than 1% by weight.

[0050] The water-soluble acid used in the present invention is an organic acid or an inorganic acid. Preferably, the water-soluble acid is chosen from among organic acids.

[0051] The inorganic acid may be chosen, for example, from the group consisting of hydrogen chloride (HCl), sulfuric acid (H2SO4), nitric acid (HNO3), phosphoric acid (H3PO4), and combinations thereof. In one embodiment of the present invention, the water-soluble acid may be inorganic phosphoric acids, such as pyrophosphoric acid, trimetaphosphoric acid, and hexametaphosphoric acid, as well as combinations thereof.

[0052] The organic acid may be chosen from, for example, those having one or more acid groups selected from the group consisting of a carboxylic acid group, a sulfuric group, a sulfonic group, a phosphonic group, a phosphoric group, a phenolic hydroxyl group, and a mixture thereof. Preferably, the organic acid is chosen from those having one or more carboxylic acid groups and / or phosphoric groups.

[0053] In a preferred embodiment of the present invention, the organic acid is a carboxylic acid. Non-limiting examples of useful carboxylic acids may include glyoxylic acid, oxalic acid, malonic acid, malic acid, glutaric acid, citraconic acid, citric acid, maleic acid, glycolic acid, succinic acid, adipic acid, tartaric acid, acetic acid, lactic acid, glyoxylic acid monohydrate, gluconic acid, propionic acid, aconitic acid and EDTA, as well as combinations thereof.

[0054] In one embodiment of the present invention, the carboxylic acid may comprise from 2 to 10 carbon atoms, preferably from 2 to 8 carbon atoms, and more preferably from 2 to 7 carbon atoms.

[0055] In another embodiment of the present invention, the organic acid is chosen from among the phosphoric acids. Non-limiting examples of useful phosphoric acids may include phytic acid, inositol triphosphate, inositol pentakisphosphate, tripolyphosphate and adenosine triphosphate, as well as their combinations.

[0056] In one embodiment of the present invention, the organic acid is chosen from monocarboxylic acids. Examples of suitable monocarboxylic acids include, but are not limited to, aryl, (hetero)cyclic, alkyl and / or aliphatic monocarboxylic acids such as, for example, acetic acid, mono-, di- or trichloroacetic acid, glyoxylic acid, glycolic acid, acrylic acid, methacrylic acid, pyruvic acid, propionic acid, D-gluconic acid and D-galacturonic acid.

[0057] In one embodiment, the organic acid may have two or more acid groups. This type of organic acid may be those having two acid groups, those having three acid groups, and those having four or more acid groups.

[0058] In one embodiment of the present invention, the organic acid having two or more acid groups may be a polycarboxylic acid.

[0059] As examples of polycarboxylic acids having two carboxylic acid groups, dicarboxylic acids can be mentioned, such as oxalic acid, malonic acid, malic acid, glutaric acid, citraconic acid, maleic acid, tartaric acid, succinic acid, adipic acid and azelaic acid.

[0060] As examples of polycarboxylic acids having three carboxylic acid groups, tricarboxylic acids, such as citric acid and aconitic acid, can be mentioned.

[0061] In a preferred embodiment, the organic acid is a tricarboxylic acid, such as citric acid and aconitic acid.

[0062] As examples of polycarboxylic acids having four or more carboxylic acid groups, tetracarboxylic acids, such as EDTA, pentacarboxylic acids and hexacarboxylic acids, may be mentioned.

[0063] In a preferred embodiment of the present invention, the water-soluble acid can be chosen from among the hydroxy acids. Therefore, the composition according to the present invention can comprise at least one hydroxy acid as component (b).

[0064] The hydroxy acid may comprise at least one mono- or polycarboxylic acid comprising at least one hydroxyl functional group. The hydroxy acid (a) may be selected from among the α- and β3-hydroxy acids. For example, the hydroxy acid (a) may be an α-hydroxy acid. The α and β3 positions reflect the fact that at least one of the hydroxyl groups occupies an α or β position relative to at least one of the carboxyl groups of the acid; that is, it is attached, respectively, either to the carbon bearing the hydroxyl group or to the carbon adjacent to the one bearing the carboxyl group. The acid may be present in a form selected from among the free acids, their associated salts (such as salts with organic bases and alkali metals), for example depending on the final pH given to the composition, and optionally the corresponding lactides (i.e. the form obtained by auto-esterification of the molecules).

[0065] The term "α-hydroxy acid" in this document means an acid, such as carboxylic acid or phosphoric acid, which has at least one hydroxyl group on the adjacent (α) carbon atom.

[0066] The α-hydroxy acid can be represented by the following chemical formula:

[0067] (Ra)(Rb)C(OH)COOH

[0068] where

[0069] Ra and Rb are H, F, Cl, Br, I, an alkyl or aralkyl group in saturated or unsaturated form, isomeric or non-isomeric, straight-chain or branched or cyclic, having 1 to 7 carbon atoms, and furthermore Ra and Rb may bear OH, CHO, COOH and an alkoxy group having 1 to 6 carbon atoms.

[0070] Typical alkyl, aralkyl and alkoxyl groups for Ra and Rb include methyl, ethyl, propyl, isopropyl, butyl and pentyl groups.

[0071] The α-hydroxy acid can be chosen, for example, from the group consisting of glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, gluconic acid, phytic acid and a mixture of these.

[0072] It is preferable that the hydroxy acid have two or more carboxylic groups, and more preferably two or three carboxylic groups.

[0073] It is also preferable that the hydroxy acid have one or more hydroxyl groups, and more preferably one or two hydroxyl groups.

[0074] It is also preferable that the hydroxyl acid be chosen from the group consisting of glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, gluconic acid, mucinic acid, phytic acid and a mixture of these.

[0075] In another preferred embodiment, the (b) water-soluble acid is selected from aliphatic monocarboxylic acids, such as glyoxylic acid, and hydroxyl acids, in particular α-hydroxy acids, such as glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, gluconic acid, mucic acid, phytic acid, and mixtures thereof.

[0076] In another preferred embodiment, the (b) water-soluble acid is selected from glyoxylic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, gluconic acid, phytic acid and a mixture thereof.

[0077] In a non-limiting embodiment, the organic acid compounds have a pKa of about 6 or less, preferably 5 or less, and more preferably 4.5 or less. The pKa of the organic acid is generally 0.5 or more, more preferably 1 or more.

[0078] In one embodiment of the present invention, the organic acid compounds may have a number average molecular weight of less than 1000 g per mole (g / mol), and preferably less than 750 g per mole (g / mol).

[0079] The water-soluble acids of the present invention may be in the form of a salt. The term "salt" in this document means a salt formed by the addition of one or more bases suitable for the acidic compounds. Examples of salts include metal salts, for example, salts with an alkali metal such as Na and K, and salts with an alkaline earth metal such as Mg and Ca, and ammonium salts.

[0080] In a preferred embodiment, the water-soluble acid is not in the form of a salt.

[0081] The water-soluble acid(s) may be present in the composition according to the present invention in an amount of 0.1% by weight or more, preferably 0.2% by weight or more, more preferably 0.5% by weight or more, even more preferably 0.7% by weight or more, and in particular 1% by weight or more; and / or may be 15% by weight or less, preferably 10% by weight or less, more preferably 7% by weight or less, even more preferably 5% by weight or less, and in particular 3% by weight or less, relative to the total weight of the composition.

[0082] The water-soluble acid(s) may be present in the composition according to the present invention in an amount of 0.1% to 15% by weight, preferably 0.2% to 10% by weight, more preferably 0.5% to 7% by weight, more preferably 0.7% to 5% by weight, and in particular 1% to 3% by weight, relative to the total weight of the composition.

[0083] (Water)

[0084] The composition according to the present invention comprises (c) water.

[0085] Water may be present in the composition according to the present invention in an amount of 50% by weight or more, preferably 65% ​​by weight or more, more preferably 80% by weight or more, and even more preferably 90% by weight or more; and / or may be 99.5% by weight or less, preferably 99% by weight or less, relative to the total weight of the composition.

[0086] (Adjuvants)

[0087] The composition according to the present invention may further include one or more optional additional adjuvants that can be used conventionally in compositions for the treatment of keratinous fibers. The adjuvants can be chosen from a physiologically acceptable medium, in particular the Water-soluble organic solvents; cationic, anionic, non-ionic or amphoteric surfactants; cationic, anionic, non-ionic, amphoteric or zwitterionic polymers or mixtures thereof; thickeners; penetration enhancers; pH adjusters; hair loss control agents; anti-dandruff agents; antioxidants; suspending agents; sequestering agents; buffers; perfumes; emollients; dispersing agents; dyes and / or pigments; film-forming agents; stabilizers; preservatives, such as phenoxyethanol; co-preservatives; opacifying agents; and mixtures thereof.

[0088] The adjuvants may be present in the second composition of the present invention in an amount ranging preferably from 0.01% to 20% by weight, preferably from 0.1% to 10% by weight, more preferably from 0.5% to 5% by weight, and even more preferably from 0.5% to 2% by weight, relative to the total weight of the composition.

[0089] In a preferred embodiment of the present invention, the composition according to the present invention comprises amino acids and / or oligopeptides in an amount of less than 1% by weight, preferably less than 0.5% by weight, and more preferably less than 0.1% by weight, relative to the total amount of the second composition. In another embodiment of the present invention, the second composition is free of amino acids and / or oligopeptides.

[0090] In another specific embodiment of the present invention, the total quantity of components (a), (b) and (c) is 70% by weight or more, preferably 75% by weight or more, more preferably 80% by weight or more, even more preferably 85% by weight or more, preferably 90% by weight or more, even more preferably 95% by weight or more, even more preferably 97% by weight or more, and in particular 98% by weight or more, relative to the total weight of the composition.

[0091] The composition according to the present invention can be prepared by mixing the essential and optional ingredients above in accordance with any of the processes well known to persons skilled in the art.

[0092] The composition according to the present invention can be used for the treatment, for example, the care or conditioning, of keratinous fibers, preferably hair.

[0093] The composition according to the present invention may be a cosmetic composition, preferably a hair cosmetic composition, and more preferably a rinse-off type hair cosmetic composition.

[0094] For example, the composition according to the present invention can be used in cosmetic hair care products such as shampoos, conditioners shampoos and other things.

[0095] The composition according to the present invention can be applied to keratinous fibers by any conventional means in the art, such as using hands, a sprayer, a brush and a comb.

[0096] In one embodiment of the present invention, the composition of the present invention can be applied to colored keratin fibers, such as dyed hair, to improve the colorfastness of the keratin fibers. In particular, the composition according to the present invention can be used for keratin fibers colored with an oxidative dye or a direct dye. The types of oxidative and direct dyes are not particularly limited, and the present invention can be used for keratin fibers colored with common oxidative or direct dyes.

[0097] [Cosmetic process and use]

[0098] The present invention also relates to a cosmetic process for the care or conditioning of keratin fibers, preferably hair, comprising the step of:

[0099] apply the composition according to the present invention to the keratinous fibers.

[0100] The application step can be carried out by any conventional means such as an applicator, for example hands, a sprayer, a brush and a comb.

[0101] In one embodiment of the present invention, the keratinous fibers are keratinous fibers colored by dyes, preferably oxidative dyes or direct dyes.

[0102] The cosmetic process according to the present invention may further include the step of leaving the composition according to the present invention on the keratin fiber for a period of 1 second to 1 hour, preferably from 10 seconds to 45 minutes, more preferably from 1 minute to 40 minutes, more preferably from 5 minutes to 30 minutes under ambient conditions.

[0103] The present invention also relates to the use of a combination of (a) at least one water-soluble silicate and (b) at least one water-soluble acid in an aqueous solution comprising (c) water and having a pH value of 2 to 10, for the purpose of caring for or conditioning keratinous fibers, such as hair, in particular to improve fiber integrity, strength and / or color durability.

[0104] EXAMPLES

[0105] The present invention will be described in more detail with the aid of examples. However, these examples shall not be construed as limiting the scope of the present invention.

[0106] [Examples 1 to 3 and comparative example 1]

[0107] (Preparation)

[0108] The compositions according to Examples 1 to 3 and Comparative Example 1 were prepared by mixing sodium metasilicate, phenoxyethanol, acidic compounds, if applicable, and water under ambient conditions. The formulations of the compositions and their pH values ​​are summarized in Table 1 below. The numerical values ​​of the quantities of ingredients shown in Table 1 are all based on "% by weight" of active raw materials.

[0109] [Tables] Ingredients Ex. 1 Ex. 2 Ex. 3 Ex. comp. 1 Sodium metasilicate 1 1 1 1 Phytic acid 1.63 - - - Citric acid - 1.7 - - Glyoxylic acid - - 1.12 - Phenoxyethanol 0.5 0.5 0.5 0.5 Deionized water qs 100 qs 100 qs 100 qs 100 pH 5 5 5 12

[0110] (Measurement of the denaturation temperature)

[0111] Three strands of hair (1 g, 27 cm) were used for each experiment. The hair strand was washed with a cleansing shampoo composition, rinsed with deionized water, and then towel-dried. The formulation of the cleansing shampoo composition is shown in Table 2 below. The numerical values ​​of the ingredient quantities shown in Table 2 are all based on "% by weight" of active raw materials. 1 g of each of the compositions according to Examples 1 to 3 and Comparative Example 1 was applied to the hair strand with a brush. The resulting treated hair strands were subjected to a temperature of denaturation analysis as explained below. In addition, the resulting treated hair strands were washed three times with an ordinary shampoo composition, and the washed hair strands were also subjected to the analysis explained below.The formulation of the composition of ordinary shampoo is shown in Table 2 below.

[0112] [Tableaux2] Ingredients Composition of Cleansing Shampoo Composition of Regular Shampoo Sodium Laureth Sulfate 12 15 Coco-betaine 10 9 Cocamide MEA 0.5 - Sodium Chloride 0.5 - Glycerin 2 - Sodium Benzoate 0.5 0.5 Salicylic Acid 0.2 0.2 Laureth-12 0.25 - Polyquaterium-10 - 0.3 Citric Acid qs pH 5.3 qs pH 5.3 Sodium Hydroxide qs pH 5.3 qs pH 5.3 Deionized Water qs 100 qs 100

[0113] The treated hair strands (hair clumps) were then left at 24°C and 40% RH for one hour. Seven to ten mg of hair strand sample were prepared by cutting the strand, and the sample was placed in a stainless steel container. After adding 50 µL of deionized water to the stainless steel container, the container was sealed and stored overnight. The denaturation temperature of the treated hair strand sample was measured using a high-pressure differential scanning calorimeter (HP-DSC, Perkin Elmer DSC8000). Heating was carried out from 25°C to 190°C at a heating rate of 10°C / min. The calculated denaturation temperatures are summarized in Table 3. The reference in Table 3 indicates the result for the untreated hair strand.

[0114] The denaturation temperature of keratin fibers corresponds to the temperature at which the keratin protein changes from an alpha to a beta structure. Therefore, keratin fibers with a higher denaturation temperature have greater integrity because the higher denaturation temperature indicates that the keratin protein can maintain its structure at a higher temperature.

[0115] [Tableaux3] Denaturing temperature (°C) Denaturing temperature (°C) after three shampoos Ex. 1 158.6 159.2 Ex. 2 159.0 159.5 Ex. 3 157.4 157.6 Ex. comp. 1 146.7 147.8 Reference 151.9 152.0

[0116] As shown in the results of Table 1, the keratin fiber treated with the composition according to Comparative Example 1 exhibited a lower denaturation temperature than the reference sample. This indicates that the keratin fiber was damaged by the application of the first composition comprising a water-soluble silicate. On the other hand, the keratin fiber treated with the compositions according to each of Examples 1 to 3 exhibited a higher denaturation temperature than Comparative Example 1, and even higher than that of the reference sample. These results indicate that the application of the composition according to the present invention could improve the integrity of the keratin fibers. These effects appear to be obtained because the internal repair of the keratin fibers can be enhanced by the composition according to the present invention.

[0117] [Examples 2 and 4 to 6 and comparative example 1].

[0118] (Preparation)

[0119] In addition to the composition according to Example 2 and Comparative Example 1, the compositions according to Examples 4 to 6 were prepared by mixing sodium metasilicate, citric acid, phenoxyethanol, and water under ambient conditions. The formulations of the compositions and their pH values ​​are summarized in Table 4 below. The numerical values ​​of the quantities of ingredients shown in Table 4 are all based on "% by weight" of active raw materials.

[0120] [Tables4] Ingredients Ex. 2 Ex. 4 Ex. 5 Ex. 6 Ex. comp. 1 Sodium metasilicate 1 1 1 1 1 Citric acid 1.7 1.1 2.67 2.9 - Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 Deionized water qs 100 qs 100 qs 100 qs 100 qs 100 pH 5 9 4 3 12

[0121] (Resistance analysis)

[0122] Two strands of hair (1 g, 27 cm) were prepared for each experiment. Each strand was washed with a cleansing shampoo composition, rinsed with deionized water, and then towel-dried. The formulation of the cleansing shampoo composition was the same as that used in the example above (see Table 2). 1 g of each of the compositions according to Examples 2 and 4 to 6 and Comparative Example 1 was applied to each strand of hair. The strand was then maintained at 24°C and 40% RH overnight to obtain a treated and dried strand.

[0123] The root of the hair strand was fixed to a plate using a clamp. The end of the loop was held and oriented upwards, then released so that the end of the loop could be directed downwards. The angle between the plate and the root of the hair strand was measured (see [Fig. 1]). The average value was determined as the bending angle. The results are shown in Table 5 below. The larger the bending angle, the greater the resistance of the hair strand.

[0124] [Tables5] pH of the composition Flexural angle (°) Ex. 2 5 75 Ex. 4 9 68.5 Ex. 5 4 71 Ex. 6 3 66 Ex. comp. 1 12 63 Reference - 61

[0125] As shown in the results of Table 5, the compositions according to each of Examples 2 and 4 to 6 significantly improved the resistance of the hair strand fiber in the pH range of 3 to 9, compared to that of comparative example 1 and the reference.

[0126] (Color lifetime)

[0127] Three strands of hair (1 g, 20 cm) were prepared for each experiment. The hair strands were dyed with an oxidative dye or a direct dye according to the following protocols to obtain colored hair strands.

[0128] - Oxidative dye

[0129] Strands of 100% natural gray Chinese hair purchased from IHIP were placed on a heated plate at 27°C. A 1:1 mixture of a colorant (Alluria Ash Blue 8.11 tone 8, L'Oréal Professionnel) and an oxidizing agent (Alluria Cream Oxidant, L'Oréal Professionnel) was applied to the hair strands at a rate of 3 g of mixture per gram of hair. The strands were left for 30 minutes in an ambient environment (25°C / 40% RH) and then rinsed with tap water at 37°C. After being washed with the cleansing shampoo composition (see Table 2), the hair strands were towel-dried and then blow-dried.

[0130] - Direct dye

[0131] Strands of 100% natural gray Chinese hair purchased from IHIP were placed on a heated plate at 27°C. A coloring product (Colorful Hair Navy Blue, L'Oréal Professionnel) was applied to the strands at a rate of 3 g / g of hair, and the strands were left for 20 minutes in an ambient environment (25°C / 40% RH), then turned over after 10 minutes, and subsequently rinsed with tap water at 37°C. After being washed with the cleansing shampoo composition (see Table 2), the hair strands were towel-dried and then blow-dried.

[0132] Each of the colored hair strands (1 g, 20 cm) was shampooed once with the ordinary shampoo composition shown in Table 2 above, then towel-dried. The hair strands were placed on a vinyl wrap in an ambient environment (25 °C / 40% RH), and 1 g of the composition according to Example 2 was applied to them. The hair strands were left for 5 minutes, then rinsed with tap water at 37 °C. The hair strands were towel-dried and dried with a hairdryer, and were ready for the experiments.

[0133] The colored hair strands obtained were shampooed with the ordinary shampoo composition shown in Table 2, rinsed with tap water at 37°C, and then dried with a hairdryer. For hair strands colored with oxidative dye, this shampooing cycle was repeated seven times. For hair strands colored with direct dye, this shampooing cycle was repeated three times.

[0134] The difference in color of the colored strand before and after shampooing for the The cycles were measured by measuring the colorimetric values ​​(L* (lightness), a* (green-red), and b* (blue-yellow)) using a Konica Minolta CM-3600A spectrophotometer. The AE* (between the color of the dyed hair strand and the color of the shampooed hair strand according to the AL*a*b system) were calculated. The smaller the AE*, the better the color durability. The results are shown in Table 6.

[0135] [Tableauxô] Hair Color Shampoo Cycle (times) AE* Example 5 Reference Oxidative Dye 7 1.44 2.14 Direct Dye 1 5.84 7.38 2 9.27 12.97 3 12.41 14.66

[0136] As shown in Table 6, the application of the composition according to the present invention to hair resulted in a lower AE* than that of the reference for both hair strands colored with an oxidative dye and a direct dye. Therefore, this result indicates that the present invention can impart improved color durability and a color-preventing effect to colored keratin fibers.

[0137] Therefore, it can be concluded that the composition according to the present invention is entirely suitable as a cosmetic composition for the treatment of keratin fibers, since it can impart highly beneficial cosmetic effects to the keratin fibers, such as improved integrity, increased fiber strength, and longer color durability. Consequently, the process according to the present invention is very useful for cosmetic purposes and can satisfy a significant consumer demand.

Claims

Demands

1. Composition for the treatment of keratinous fibers, preferably hair, comprising: a. at least one water-soluble silicate, in a content of 0.8% to 2% by weight, relative to the total weight of the composition; b. at least one water-soluble acid, in a content of 1% to 3% by weight relative to the total weight of the composition; and c. water, wherein the composition is in the form of an aqueous solution and has a pH value of 2 to 10, wherein (a) the water-soluble silicate is selected from sodium silicates and (b) the water-soluble acid is citric acid.

2. Composition according to claim 1, wherein the (a) water-soluble silicate is sodium metasilicate.

3. Composition according to any one of the preceding claims, wherein the pH value of the composition ranges from 3 to 9, more preferably from 3 to 8, more preferably still from 3 to 6, and in particular from 4 to 6.

4. Cosmetic process for the care or conditioning of keratinous fibers, preferably hair, comprising the step of: applying to the keratinous fibers the composition according to any one of the preceding claims.

5. Use of a combination of (a) at least one water-soluble silicate and (b) at least one water-soluble acid in an aqueous solution comprising (c) water and having a pH value of 2 to 10, for the care or conditioning of keratinous fibers, such as hair.

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