FR3146065A1 - USE OF A BROMINE-BASED ACID DYE AS AN ANTI-NAIL DYSCHROMIA AGENT IN NAIL VARNISH COMPOSITIONS AND ANHYDROUS COMPOSITIONS FOR NAIL VARNISHES COMPRISING SAID BROMINE-BASED ACID DYE - Google Patents

Abstract

The present invention relates to the use of a bromine-based acid dye as an anti-dyschromia agent in a nail polish, as well as to an anhydrous composition for transparent nail polishes, comprising said bromine-based acid dye and suitable polish co-formulants. According to another aspect, the present invention relates to a method for counteracting nail dyschromia, the method comprising the step of applying the anhydrous composition to the nail. Furthermore, the present invention relates to the use of the anhydrous composition as a transparent nail polish base. Class: A61Q

Description

USE OF A BROMINE-BASED ACID DYE AS AN ANTI-NAIL DYSCHROMIA AGENT IN NAIL VARNISH COMPOSITIONS AND ANHYDROUS COMPOSITIONS FOR NAIL VARNISHES COMPRISING SAID BROMINE-BASED ACID DYE FIELD OF THE INVENTION

The present invention relates to the use of a bromine-based acid dye as an anti-dyschromia agent in a transparent nail polish, as well as to an anhydrous composition for nail polishes, comprising said bromine-based acid dye and suitable polish co-formulants. According to another aspect, the present invention relates to a method for counteracting nail dyschromia, the method comprising the step of applying the anhydrous composition to the nail. Furthermore, the present invention relates to the use of the anhydrous composition as a transparent nail polish base.

STATE OF THE ART

Clean, well-groomed nails are always appreciated. However, for a number of reasons nails can turn yellow, gray or stained, and/or become brittle, for example:

• prolonged use of nail polish. Frequent use of nail polish, especially those with a dark shade or gel polish, together with repeated use of strong acetone-based removers, can give the nail plate a pale yellow color. This can also happen if the nail polish is kept on for too long, which causes the pigments in the nail polish to have a negative effect on the keratin of the nail, often causing it to be brittle as well;

• Gel nail polish. Gel nails allow people to have long, natural-looking nails. They are made from a hard gel that hardens under a UV or LED lamp to make them more resistant. Repetitive or prolonged use of UV gel coats can prevent the nails from breathing or receiving natural light, therefore hindering healthy growth and causing yellowing of the nails;

• Wearing nail extensions. The term “nail extensions” refers to artificial nails that are attached to natural nails and decorated with nail art. Keeping these artificial nails on for a long time and/or not placing them correctly can damage the nail bed. Artificial nails also block natural air and light from reaching the nails, increasing the risk of fungal infections and therefore yellow/grey/stained nails.

• tobacco. Nails are exposed to harmful toxins in cigarette smoke, such as nicotine and tar, which can cause nails to turn an undesirable yellow color;

• fungal infections, more commonly seen on toenails than fingernails. Discoloration is worsened by wearing tight-fitting shoes or trauma to the nail plates, and may also be associated with athlete's foot. The most common fungal infection is caused by the Trichophyton family;

• Occasionally nails may turn yellow/turn grey/become stained and this can be a symptom of something more serious, such as chronic lung conditions, internal malignancies, lymphatic obstructions, and even rheumatoid arthritis.

The treatment for yellow/grey/stained nails will therefore depend on the cause. The most likely cause is that the nails have become discoloured due to an infection or a product used. There are home remedies in these cases, to counteract the alterations in the colour of the nails, for example lemon juice, apple cider vinegar, or a hydrogen peroxide solution. All these remedies work in the same way, that is, they reduce the pH by treating the nails with acidic conditions, so that the yellow spots on the nails turn white.

In fact, most people try to simply cover their discolored nails with a classic high coverage nail polish (sometimes even with added pearlescent), but obviously this does not solve the actual underlying problem as such. In fact, this temporary and aesthetic remedy will make the problem worse, frequent use of nail polish being – as mentioned above – one of the common reasons for yellow nails.

In view of the above, the present invention aims to provide a solution for overcoming the problem of nail color changes in an effective manner, while preserving the health of the nails.

This and other objectives are achieved by using a bromine-based acid dye selected from Red 21 (INCI name CI 45380, Unicert Red K7061-J), Red 27 (INCI name CI 45410, Unicert Red K7053-J), Orange 5 (INCI name CI 45370, Unicert Orange K7003-J) and mixtures thereof, as an anti-dyschromia agent in a transparent nail polish.

The term "dyschromia" includes any alteration of color of the nail, such as yellowing, graying, staining, or discoloration.

According to another aspect, the present invention relates to an anhydrous composition for transparent nail polishes, the composition comprising a bromine-based acid dye as defined above, and suitable polish co-formulants, for example solvents, film-forming agents and a plasticizer.

According to another aspect, the present invention relates to a method for counteracting nail dyschromia, the method comprising the step of applying the anhydrous composition to the nail.

According to a further aspect, the present invention relates to the use of the anhydrous composition as a transparent nail polish base.

The features and advantages of the present invention will become apparent from the following detailed description, from the illustrative examples of implementation provided, and from the accompanying figures, in which:

there shows an exemplary nail composition according to the invention in its initial appearance, on the left, and once applied to the nail, on the right;

there shows the influence of pH on different nail compositions according to the invention;

there shows the results of tests carried out on nails, in accordance with Example 1;

there shows a comparison between nails bearing the composition of Example 1A, and the same nails after its removal;

there shows a comparison between an initially yellowed nail and the same nail bearing the composition of Example 4; and

there shows a comparison between an initially untreated nail, a nail carrying the composition of Example 1, and a nail carrying the composition of Example 4.

DETAILED DESCRIPTION OF THE INVENTION

The present invention therefore relates to the use of a bromine-based acid dye selected from Red 21 (INCI name CI 45380, Unicert Red K7061-J), Red 27 (INCI name CI 45410, Unicert Red K7053-J), Orange 5 (INCI name CI 45370, Unicert Orange K7003-J) and mixtures thereof, as an anti-dyschromia agent in a transparent nail polish.

It was surprising to discover that the presence of this bromine-based acid dye in the anhydrous composition not only allows to obtain a pleasant shade on the nails, but also and unexpectedly to counteract the alterations of color of the nails and to achieve a healthy and natural appearance, which can be seen even after the composition is removed from the nails. In more detail, the anhydrous composition of the invention is effective not only against yellowing of the nails, but also against grayish nails and stained nails, especially after a manicure that looks unhealthy and unattractive.

In particular, Red 21 is a chemical compound with the CAS number: 17372-87-1, the IUPAC name: 2-(2,4,5,7-tetrabromo-6-oxido-3-oxoxanthen-9-yl)benzoate de disodium, and the following structure:

Red 27 is a chemical compound with the CAS number: 13473-26-2, the IUPAC name: 2',4',5',7'-tetrabromo-4,5,6,7-tetrachloro-3',6'-dihydroxyspiro[2-benzofuran-3,9'-xanthene]-1-one, and the following structure:

Orange 5 is a chemical compound with the CAS number: 4372-02-5, the IUPAC name: 4',5'-dibromo-3-oxospiro[2-benzofuran-1,9'-xanthene]-3',6'-diolate disodium, and the following structure:

It has been unexpectedly discovered that the above compounds turn pink or orange (depending on the color index used) when in contact with bare nails, even if the starting solution is clear, white or slightly colored. As illustrated by way of example in , Red 21 is diluted in solvents, together with other dyes (i.e. Blue 1 and Yellow 11), and packaged in a bottle, where it has a transparent and pale green appearance, while the same applied to the nail gives a healthy pink shade. When a composition is prepared without other dyes, the resulting color is pale yellow, while giving the same healthy pink shade to the nails. This means that the presence of other dyes does not interfere with the anti-dyschromia action of Red 21.

It has also been observed that the resulting color on the nails depends on the pH of the nail surface. In fact, it has been observed that the higher the pH of the nail surface, the more intense the resulting color, as shown in , where 0.5 g/L solutions of each bromine-based acid dye in ethyl acetate were tested at different pHs.

Furthermore, the higher the percentage of bromine-based acid dye, the more effective the action against colour alterations on the nail. In this regard, a number of samples have been tested, as also set out in the examples below, demonstrating that the initial yellowish appearance can be successfully and satisfactorily transformed into a more pleasant and appreciable pink or orange shade.

Accordingly, in another aspect, the present invention relates to an anhydrous composition for transparent nail polishes, the composition comprising a bromine-based acid dye as defined above, and suitable polish co-formulants, for example solvents, film-forming agents and a plasticizer.

Preferably, said anhydrous composition comprises 0.001 to 15.0 wt. % of a bromine-based acid dye selected from Red 21, Red 27, Orange 5, and mixtures thereof, as an anti-dyschromia agent, more preferably 0.01 to 1.0 wt. % of a bromine-based acid dye.

As used herein, “wt%” means weight percentage, based on the weight of the composition.

In preferred embodiments, said bromine-based acid dye is the only anti-dyschromia agent present in the anhydrous composition.

As mentioned, the anhydrous composition is intended for transparent nail polishes. This means that the final effect on the nails is not due to the formation of an opaque layer masking the yellowed nail, but rather to the reaction of the dye to the pH of the nail surface.

Preferably, the anhydrous composition according to the invention is a nitrocellulose-based nail polish, since the film-forming agent comprises nitrocellulose (cellulose nitrate – the cellulose may be derived from cotton linters and/or wood pulp). Nitrocellulose can be purchased in various viscosities to match the desired viscosity of the final product.

Preferably, the nitrocellulose is an RS type nitrocellulose with a nitrogen content of 11.5 to 12.4% (other types may be used, e.g. ½ second RS, ¼ second RS, 5/6 second RS), or a mixture thereof.

In preferred embodiments, the film-forming agent comprises nitrocellulose in an amount of up to 90% by weight based on the weight of the film-forming agent.

In addition to said nitrocellulose, there are other suitable film-forming agents:

- film-forming cellulose derivatives, preferably cellulose esters, such as cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose ethers or a mixture thereof,

- synthetic polymers, such as polyesters, epoxy resins, vinyl resins, poly(vinyl alcohol), crosslinked poly(vinyl alcohol), polybutene, VP/VA copolymer, polyurethane, hydrogenated polycyclopentadiene, or a mixture thereof,

- silicone resins, preferably trimethylsiloxysilicate, polymethylsilsesquioxane, C26-28 Alkyl Dimethicone,

- ether-based resins, preferably polyvinyl stearyl ether.

Preferably, the anhydrous composition according to the invention comprises 5 to 25% by weight of at least one film-forming agent, based on the weight of the anhydrous composition, more preferably 10 to 25% by weight.

Film-forming co-agents may also be present, for example acrylate copolymers, adipic acid/neopentyl glycol/trimellitic anhydride copolymers, or capryloyl glycerin/sebacic acid copolymer.

Preferably, the anhydrous composition according to the invention also contains at least one plasticizer, at least one solvent, at least one rheological agent, and at least one colorant, whereas, being anhydrous, it does not contain water.

Plasticizers are added to improve the flexibility and mechanical strength of the final nail polish film. Preferably, the anhydrous composition according to the invention comprises 1 to 10% by weight of at least one plasticizer, based on the weight of the anhydrous composition, more preferably 4 to 10% by weight.

Suitable plasticizers include castor oil, amyl and butyl stearate, citrates (such as acetyl triethyl citrate, acetyl tributyl citrate, acetyl trihexyl citrate, triethyl citrate), adipates, sebacates, sucrose acetate isobutyrate, sucrose benzoate, glycol esters, fatty acids, camphor, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dipropylene glycol dibenzoate, and trimethylpentanediyl dibenzoate.

Preferred plasticizers are citrates selected from acetyl triethyl citrate, acetyl tributyl citrate, acetyl trihexyl citrate, triethyl citrate, and mixtures thereof.

The anhydrous composition may also contain at least one rheological agent, which may serve to thicken the composition in order to suspend the colorants (for example especially pigments and pearls), while ensuring better spreading on the nail.

Preferably, the anhydrous composition according to the invention comprises up to 5% by weight of at least one rheological agent, based on the weight of the anhydrous composition, more preferably up to 2% by weight.

Typical rheological agents used in nail polish compositions are organically treated bentonite and hectorite. Preferably, said at least one rheological agent is selected from stearalkonium hectorite, stearalkonium bentonite, montmorillonite clays, treated clays, and mixtures thereof.

Other suitable rheological agents include silica and thixotropic alkyds.

Optionally, chemical or physical sunscreens can be added, for example diethylamino hydroxybenzoyl hexyl benzoate.

The colorants and other constituents of nail polish are typically contained in one or more solvents until the polish is applied. After application, the solvent must be allowed to evaporate.

Preferably, the anhydrous composition according to the invention comprises 50 to 70% by weight of at least one solvent, based on the weight of the anhydrous composition.

Butyl acetate, isobutyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, acetone, ethyl alcohol, and isopropyl alcohol are the most commonly used solvents, but silicone solvents such as silanes and siloxanes are also suitable. Amyl acetate, heptane, butan-1-ol, butan-2-ol, methyl ethyl ketone, and water are other suitable solvents. In preferred embodiments, the solvent is butyl acetate, isobutyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, or a mixture thereof.

Preferably, the anhydrous composition according to the invention may comprise additional colorants, for example pigments.

In addition to the usual colorants, other color tones can be added depending on the color, tone, and hue of the desired product. Natural and synthetic mica products, borosilicates, bismuth oxychloride called "pearl essence" are common white, iridescent or colored additives, such as glitter, which can also be mixed with gold, silver and bronze tones.

It should be noted that the presence of other dyes does not affect or interfere with the anti-dyschromia action of the bromine-based acid dye according to the invention.

Optionally, the anhydrous composition may further comprise at least one cosmetically acceptable additive selected from surfactants, emulsifiers, emollients, moisturizers, humectants, fragrances, biocides, preservatives, chelating agents, antioxidants, antimicrobial agents, antifungals, antiperspirants, exfoliants, vitamins, alpha-hydroxy acids, beta-hydroxy acids, retinols, niacinamide, lightening agents, ultraviolet radiation absorbers, botanical extracts, organic oils, waxes, high refractive index materials, and mixtures thereof.

In preferred embodiments, the anhydrous composition comprises:

0.001 to 5.0% by weight of a bromine-based acid dye selected from Red 21, Red 27, Orange 5, and mixtures thereof,

5 to 25% by weight of at least one film-forming agent,

1 to 10% by weight of at least one plasticizer,

50 to 70% by weight of at least one solvent, and

up to 5% by weight of at least one rheological agent,

on the weight of the anhydrous composition.

More preferably, the anhydrous composition comprises:

0.01 to 1.0% by weight of a bromine-based acid dye selected from Red 21, Red 27, Orange 5, and mixtures thereof,

10 to 25% by weight of at least one film-forming agent,

4 to 10% by weight of at least one plasticizer,

50 to 70% by weight of at least one solvent, and

up to 2% by weight of at least one rheological agent,

on the weight of the anhydrous composition.

The anhydrous nail polish composition as described above is in liquid form at room temperature and can be applied directly to the nails, for example using a brush.

In some embodiments, the anhydrous nail polish composition of the present invention consists essentially of a bromine-based acidic colorant, at least one plasticizer, at least one solvent, at least one rheological agent, and at least one film-forming agent, as described above. The term “consists essentially of” means that said bromine-based acidic colorant is the only anti-dyschromia agent in the composition, while other colorants, if any, do not interfere with or hinder this action.

In other embodiments, the anhydrous nail polish composition of the present invention comprises a bromine-based acid dye, at least one plasticizer, at least one solvent, at least one rheological agent, at least one colorant, and at least one film-forming agent, as described above.

According to another aspect, the present invention relates to a method for counteracting nail dyschromia, the method comprising the step of applying the anhydrous composition to the nail.

In fact, the composition according to the invention can be used directly on the nails or can be used in conjunction with other nail polishes.

When used directly on the nails, the anhydrous composition according to the invention allows to obtain a very natural and healthy appearance, whereas when used in combination with other dyes or nail polishes, yellowing, graying and/or staining are effectively covered and the pleasant pink color persists even after removing the polish with conventional nail polish removers.

Accordingly, according to another aspect, the present invention relates to the use of the anhydrous composition as a nail polish base.

It is to be understood that all aspects identified as preferred and advantageous for the bromine-based acid dye and the anhydrous composition are to be considered similarly preferred and advantageous also for the uses, and methods of application thereof.

It is also to be understood that all combinations of preferred aspects of the bromine-based acid dye and the anhydrous composition according to the invention, as well as uses, and methods of application, as set forth above, are to be considered as described herein.

Examples of implementing the present invention provided for illustrative purposes are given below.

EXAMPLES

Example 1.

The following dye solutions were prepared and incorporated into standard nail polish compositions: Ref. Dye Concentration Solvent:
ethyl acetate Ex. 1A RED 21 6.55% by weight 0.2% by weight Ex. 1B RED 27 10.00% by weight 0.2% by weight Ex. 1C ORANGE 5 11.68% by weight 0.2% by weight Ex. 1D RED 21 9.00% by weight 0.2% by weight

where “% by weight” means percentage by weight, based on the weight of the composition.

The term “standard nail polish compositions” means that each sample above was added to the same mixture of nitrocellulose, polyester resins, and citrate plasticizer, so the colorant is the only variable being tested.

In reference to the , it has been observed that, on bare nails, after application of the above compositions, the resulting overall appearance and effect are significantly improved and pleasant, and a healthy and natural pink shade is obtained, the latter being the result of the reaction of the dye to the pH of the nail surface (and not the formation of an opaque layer).

The said appearance is preserved even after 24 hours, and, much more unexpectedly, even after the compositions have been removed from the nails using a classic nail polish remover, the nails appear naturally pink and healthy.

Example 2.

The following composition was prepared: Ingredients % by weight Solvent:
ETHYL ACETATE, BUTYL ACETATE 68,800 Film-forming agent:
NITROCELLULOSE (70%) 16,000 Co-film-forming agent:
ACRYLATE COPOLYMER or
ADIPIC ACID/NEOPENTYL GLYCOL/TRIMELLITIC ANHYDRIDE COPOLYMER 8,499 Plasticizer:
TRIBUTYL ACETYLCITRATE 6,500 Bromine-based acid dye:
RED 21 or RED 27 or ORANGE 5 0.001 Stabilizer:
CITRIC ACID 0.100 ALOE VERA OIL 0.100 TOTAL 100,000

Example 3.

The following composition was prepared: Ingredients % by weight Solvent:
ETHYL ACETATE, BUTYL ACETATE, ISOPROPYL ACETATE 68,848 Film-forming agent:
Cellulose acetate butyrate 16,000 Co-film-forming agent:
ACRYLATE COPOLYMER or
ADIPIC ACID/NEOPENTYL GLYCOL/TRIMELLITIC ANHYDRIDE COPOLYMER 8,500 Plasticizer:
TRIBUTYL ACETYLCITRATE 6,500 Bromine-based acid dye:
RED 21 or RED 27 or ORANGE 5 0.050 Stabilizer:
CITRIC ACID 0.100 YELLOW 11 CI 47000 0.001 BLUE 1 CI 42090 0.001 TOTAL 100,000

In reference to the , it can be observed that, 5 minutes after application, the color of the nail changes immediately, going from a slightly yellow color at the beginning to pink. 5 minutes after removing the nail composition using a classic nail polish remover, the pink shade persists on the nails, and the nails take on a healthy and pleasant appearance over time.

Example 4. Ingredients % by weight Solvent:
ETHYL ACETATE, BUTYL ACETATE, ISOPROPYL ACETATE 64,440 Film-forming agent:
NITROCELLULOSE (70%) 16,000 Co-film-forming agent:
ACRYLATE COPOLYMER or
ADIPIC ACID/NEOPENTYL GLYCOL/TRIMELLITIC ANHYDRIDE COPOLYMER 8,500 Plasticizer:
TRIBUTYL ACETYLCITRATE or
DIPROPYLENE GLYCOL DIBENZOATE 6,500 Bromine-based acid dye:
RED 21 or RED 27 or ORANGE 5 0.050 Suspension agent:
BENTONITE or STEARALKONIUM HECTORITE or SILICA 2,000 Stabilizer:
PHOSPHORIC ACID or CITRIC ACID 0.010 PIGMENTS:
CI 12085 RED 36
CI 77891 TITANIUM DIOXIDE 2,500 TOTAL 100,000

As shown in the , an initially yellowed nail (on the left) was treated with the composition of Example 4, in which Red 21 was used (on the right). It can be immediately noted that the appearance of the treated nail is clearly improved and pink, which gives a healthy and pleasant appearance.

On the , an initially untreated nail is shown (left), compared to a nail treated with the composition of Example 1, in which Red 27 was used (middle), and to a nail treated with the composition of Example 4, in which Red 27 was used (right). In this case too, the treated nails had a better overall appearance than the untreated nail.

Claims (10)

Cosmetic use of a bromine-based acid dye selected from Red 21 (INCI name CI 45380, Unicert Red K7061-J), Red 27 (INCI name CI 45410, Unicert Red K7053-J), Orange 5 (INCI name CI 45370, Unicert Orange K7003-J) and mixtures thereof, as an anti-nail discoloration agent in a transparent nail polish. Anhydrous composition for transparent nail polishes, the composition comprising a bromine-based acid dye as defined in claim 1, as an anti-nail discoloration agent, and suitable nail polish co-formulants. An anhydrous composition according to claim 2, comprising 0.001 to 15.0% by weight of said bromine-based acid dye, based on the weight of the composition. Anhydrous composition according to claim 2 or 3, wherein said bromine-based acid dye is the only anti-nail dyschromia agent present in the anhydrous composition. Anhydrous composition according to any one of claims 2 to 4, comprising:
0.001 to 5.0% by weight of a bromine-based acid dye selected from Red 21, Red 27, Orange 5, and mixtures thereof,
5 to 25% by weight of at least one film-forming agent,
1 to 10% by weight of at least one plasticizer,
50 to 70% by weight of at least one solvent, and
up to 5% by weight of at least one rheological agent,
on the weight of the anhydrous composition. An anhydrous composition according to any one of claims 2 to 5, comprising 0.01 to 1.0% by weight of said bromine-based acid dye, based on the weight of the composition. Anhydrous composition according to claim 6, comprising:
0.01 to 1.0% by weight of a bromine-based acid dye selected from Red 21, Red 27, Orange 5, and mixtures thereof,
10 to 25% by weight of at least one film-forming agent,
4 to 10% by weight of at least one plasticizer,
50 to 70% by weight of at least one solvent, and
up to 2% by weight of at least one rheological agent,
on the weight of the anhydrous composition. An anhydrous composition according to any one of claims 2 to 7, comprising a solvent selected from butyl acetate, isobutyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, or mixtures thereof. A method for counteracting nail dyschromia, the method comprising the step of applying the anhydrous composition according to any one of claims 2 to 8 to the nails. Cosmetic use of the anhydrous composition according to any one of claims 2 to 8, as a transparent nail polish base.