COSMETIC COMPOSITION OF NON-AQUEOUS THIXOTROPIC NAIL VARNISH CONTAINING A NAIL-HARDENING AGENT, USE AND IMPLEMENTATION METHOD

Abstract

The invention concerns a cosmetic composition of non-aqueous thixotropic nail varnish containing a film-forming agent comprising nitrocellulose, at least one organic solvent, and a thixotropic agent, characterised in that it contains sorbic acid or one of the salts of same at a concentration of less than or equal to 1% by weight of sorbic acid and in that the thixotropic agent, present at a concentration of between 0.1 and 4% by weight of the composition, is a clay modified with a quaternary amine, neutralised by a strong acid at a concentration of less than 0.1% by weight. The sorbic acid, or one of the salts of same, is used as a hardening agent in such a cosmetic composition applied to nails free of fungal infection. The invention also concerns a method for strengthening and hardening nails free of fungal infection, in particular cracked, thin, brittle, soft or split nails, consisting of applying a composition containing sorbic acid or one of the salts of same topically to said nails and/or the periphery of same.

Claims

1. A non-aqueous thixotropic cosmetic nail varnish composition comprising: a film-forming agent having nitrocellulose, at least one organic solvent, and a thixotropic agent, wherein said composition contains sorbic acid or one of its salts at a concentration of less than or equal to 1% by weight and in that the thixotropic agent, present at a concentration of between 0.1% and 4% by weight of the composition, is a clay modified with a quaternary amine, neutralized by a strong acid at a concentration of less than 0.1% by weight of the composition.

2. The cosmetic nail varnish composition as claimed in claim 1, wherein said cosmetic nail varnish contains a concentration of sorbic acid or one of its salts of less than or equal to 0.5% by weight.

3. The cosmetic nail varnish composition as claimed in claim 1, wherein the thixotropic agent is a clay modified with a quaternary amine, the clay being chosen from bentonite or hectorite.

4. The cosmetic nail varnish composition as claimed in claim 1, wherein the concentration of thixotropic agent is between 0.5% and 3% by weight, of the composition.

5. The cosmetic nail varnish composition as claimed in claim 1, wherein the strong acid which neutralizes the clay modified with a quaternary amine is phosphoric acid, preferably at a concentration of less than or equal to 0.05% by weight.

6. The cosmetic nail varnish composition as claimed in claim 1, wherein the concentration of nitrocellulose is between 8% and 30% by weight, preferably between 10% and 25% by weight.

7. The cosmetic nail varnish composition as claimed in claim 1, wherein the sorbic acid or one of its salts is used as a hardening agent for the nails.

8. The cosmetic nail varnish composition as claimed in claim 1, wherein the composition is a cosmetic composition in the form of a colored or colorless nail varnish, of a varnish base coat, or of a peelable varnish.

9. A sorbic acid, or one of its salts, as a nail-hardening agent at a concentration of less than 1% by weight, Wherein said sorbic acid is included in a cosmetic composition as claimed in claim 1 that is applied to nails free from fungal infection.

10. The sorbic acid or one of its salts as claimed in claim 9, wherein the cosmetic composition contains a concentration of sorbic acid or of one of its salts of less than or equal to 0.5% by weight.

11. The sorbic acid or one of its salts as claimed in either of claim 9, wherein the cosmetic composition contains a concentration of sorbic acid or of one of its salts of between 0.01% and 0.5% by weight, more preferably of between 0.05% and 0.1% by weight.

12. A method for strengthening and hardening nails free from fungal infection, in particular cracked, thin, brittle, soft or split nails, consisting of: topically applying to said nails a cosmetic varnish composition as claimed in claim 1.

13. The cosmetic nail varnish composition as claimed in claim 2, wherein said cosmetic nail varnish contains a concentration of sorbic acid or one of its salts between 0.01% at 0.5% by weight.

14. The cosmetic nail varnish composition as claimed in claim 2, wherein said cosmetic nail varnish contains a concentration of sorbic acid or one of its salts between 0.05% and 0.1% by weight.

15. The cosmetic nail varnish composition as claimed in claim 4, wherein the concentration of thixotropic agent is between 1% and 2% by weight, of the composition.

16. The cosmetic nail varnish composition as claimed in claim 5, wherein the strong acid which neutralizes the clay modified with a quaternary amine is phosphoric acid, preferably at a concentration of less than or equal to 0.03% by weight, of the composition.

17. The cosmetic nail varnish composition as claimed in claim 7, wherein the concentration of nitrocellulose is between 10% and 25% by weight, of the composition.

18. The cosmetic nail varnish composition as claimed in claim 7, wherein the concentration of nitrocellulose is between 12% and 20% by weight, of the composition.

19. The sorbic acid or one of its salts as claimed in either of claim 9, wherein the cosmetic composition contains a concentration of sorbic acid or of one of its salts of between 0.05% and 0.1% by weight.

Description

EXAMPLES

[0034] Various cosmetic compositions in the form of nail varnish of the organic-solvent-based varnish type were prepared and applied to nails. The tests hereinafter were performed on these varnishes: [0035] Gloss: 100 μm of varnish was applied to a Leneta-type panel. After drying, the gloss was measured at an angle of incidence of 60° using a Minolta 268 glossmeter. [0036] Flexibility: An aluminum plate covered with a varnish of 300 μm wet is subjected to a slow stamping and the depth of the penetration is measured (ISO1520). [0037] Varnish hardness: It was measured using a Persoz pendulum on a glass plate covered with a varnish with a thickness of 100 μm wet, after drying at room temperature, according to the ISO1522 standard. [0038] Adhesion: A “cross hatch test” is carried out on a glass plate. A score of 0 corresponds to an absence of loss of adhesion. A score of 5 corresponds to a total loss of adhesion. [0039] Solids content: Between 0.5 and 1 g of varnish is poured into a dish. This dish is then placed into an oven for 3 hours at 100° C., then weighed to calculate the solids content of the varnish. [0040] Yellowing stability: The varnishes are packaged in glass bottles and stored in an oven at 50° C. for 1 month. The color of the varnish is then compared to a reference varnish not containing any hardening agent. [0041] Sedimentation stability: A tinted varnish composition containing pearlescent agent and a coloring solution is prepared and is placed in an oven for 1 month at 45° C. A visual observation is made to check whether the pearlescent agent has or has not sedimented out. [0042] Shade stability: A tinted varnish containing a mixture of the following pigments: titanium dioxide, Red 34 and ferric ferrocyanide blue, is placed in an oven at 45° C. for 30 days. The stability of this shade, and more specifically the appearance or not of any syneresis, is observed. [0043] Odor: The odor of the varnish is compared to that of a varnish not containing any hardening agent. [0044] Viscosity: The viscosity of the product is measured at 25° C. using a Brookfield viscometer. The measurements are taken after rotating for one minute at 6 rpm, then after one minute at 60 rpm, and lastly after one minute at 6 rpm. The values are given in mPa.s.

Examples 1 to 3, Comparative Example 4

[0045] Cosmetic compositions in the form of nail varnish of the organic-solvent-based varnish type were prepared from the constituents presented in the following table 1. These compositions contained variable concentrations of sorbic acid, between 0.05% and 1% by weight.

TABLE-US-00001 TABLE 1 Comp. Ex. 1 Ex. 2 Ex. 3 ex. 4 Composition Butyl acetate 42.52 42.47 42.07 41.57 Ethyl acetate 20.6 20.6 20.6 20.6 Nitrocellulose 14 14 14 14 Polyester resin 9.5 9.5 9.5 9.5 Tributyl acetylcitrate 6 6 6 6 Isopropyl alcohol 6 6 6 6 Stearalkonium bentonite 1.3 1.3 1.3 1.3 Phosphoric acid 0.03 0.03 0.03 0.03 Sorbic acid 0.05 0.1 0.5 1 Results Stability OK OK OK Yellowing Varnish hardness (s) 240 248 243 235 Viscosity (mPa .Math. s)  6 rpm 3300 3250 3290 3320 60 rpm 1030 1020 1040 1030  6 rpm 2100 2090 2120 2140 Shade stability No No No No syneresis syneresis syneresis syneresis Adhesion 0 0 0 0

[0046] The polyester resin of table 1 above is an adipic acid/neopentyl glycol/trimellitic anhydride copolymer diluted to 70% solids content in butyl acetate. The nitrocellulose is wetted to 70% in isopropanol.

[0047] These cosmetic compositions are in the form of a varnish, which is colorless and transparent after application to the nail, having a solids content equal to 24% by weight to (measured at 100° C.). One or more coloring substances chosen from pigments, soluble dyes and decorative particles, such as pearlescent agents and glitter, may be added.

[0048] It is noted that the maximum amount of sorbic acid that can be incorporated into the varnish without causing yellowing is less than 1% by weight.

[0049] In addition, sorbic acid at these concentrations of less than 1% by weight does not exhibit an odor unpleasant to the user. It also does not have any influence on the viscosity of the varnish composition or on the stability thereof.

Comparative Examples 5-6 and 9, and Example 7

In Vivo Tests

[0050] Four varnish compositions according to example 1, each containing 0.05% by weight of hardening agent, and a reference varnish composition without hardening agent were each subjected to in vivo tests on panels of 30 persons aged at least 20 years for three weeks in order to evaluate the efficacy and the tolerance thereof. None of the persons tested exhibited any lesion at the site of the target zones (here the periphery of the nails of the hand), or any dermatological condition, or any fungal infection of the nails. The varnish was applied under normal conditions of use (namely one application every three days, after having removed the previous varnish).

[0051] Comparative composition 5 contained 0.05% of hexane, comparative composition 6 contained 0.05% by weight of citral, comparative composition 9 contained 0.05% by weight of caproic acid and composition 7 according to the present invention contained 0.05% by weight of sorbic acid. Varnish composition 8 did not contain any hardening agent (reference composition).

[0052] The respective compositions and also the results of the physical tests and observed by the panelists are collated in table 2 hereinafter.

TABLE-US-00002 TABLE 2 Comp. Comp. Ex. 8 Comp. ex. 5 ex. 6 Ex. 7 (ref.) ex. 9 Compositions Butyl acetate 42.53 42.52 42.52 42.57 42.52 Ethyl acetate 20.6 20.6 20.6 20.6 20.6 Nitrocellulose 14 14 14 14 14 Polyester resin 9.5 9.5 9.5 9.5 9.5 Tributyl 6 6 6 6 6 acetylcitrate Isopropyl 6 6 6 6 6 alcohol Stearalkonium 1.3 1.3 1.3 1.3 1.3 bentonite Phosphoric 0.03 0.03 0.03 0.03 0.03 acid Hexanal 0.05 — — — — Citral — 0.05 — — — Sorbic acid — — 0.05 — — Caproic acid 0.05 Test results Gloss 86.7 87.1 87 86.9 Flexibility 4.5 4.4 4.6 4.4 4.4 Varnish 236 233 240 238 235 hardness (s) Adhesion 0 0 0 0 0 Solids content 28.1 28.3 27.9 28 28.1 Stability OK OK OK Reference OK Odor Strong Light and Absence Reference Absence pleasant Nail hardness Number of 23 18 25 12 14 people answering Yes Percentage 76.7 60.0 83.3 40.0 46.7

[0053] No clinical signs of intolerance were noted or felt by the persons tested. No symptoms of allergies were recorded.

[0054] In addition, more than 83% of the subjects found an overall improvement in the quality and the hardness of their nails. These results demonstrate the in vivo nail-hardening properties of sorbic acid, this occurring at a low concentration (0.05% by weight) in the varnish composition.

Examples 11 and 12-Comparative Examples 10 and 13

Sedimentation Stability and Color Fastness

[0055] To check the sedimentation stability, two coloring substances were added to the base varnish composition as claimed in claim 2:

[0056] firstly, a pearlescent agent: titanium oxide-coated mica sold under the name Flamenco Gold, 6-48 μm, by BASF,

[0057] and, secondly, Pigment Red 34: organic pigment sold by Sun Chemical.

[0058] This pigment was ground in order to be able to be incorporated. The grinding procedure included mixing the solvents with the pigment, stirring to deagglomerate the pigment, then incorporating the nitrocellulose. Once the latter had dissolved, the plasticizer was incorporated with stirring, which was continued for 20 minutes. The mixture obtained was then ground in a ball mill.

[0059] The Pigment Red 34 was thus ground with the following constituents (% by weight):

TABLE-US-00003 TABLE 3 Butyl acetate 30 Ethyl acetate 30 Plasticizer (TAC) 10 Red 34 10 Nitrocellulose 20

[0060] The following shade was produced in each of the tests described hereinafter:

TABLE-US-00004 Base varnish composition 95% by weight Solution containing the Red 34  3% by weight

[0061] Titanium oxide-coated mica (Flamenco Gold, 6-48 μm, from BASF) 2% by weight The stability of the compositions thus prepared was evaluated by visual observation after storage for one month at 45° C.

TABLE-US-00005 TABLE 4 Ex. 10 Ex. 13 Ex. 2 (comp.) Ex. 11 Ex. 12 (comp.) Composition Butyl acetate 42.47 42.52 42.49 42.45 42.4 Ethyl acetate 20.6 20.6 20.6 20.6 20.6 Nitrocellulose 14 14 14 14 14 Polyester resin 9.5 9.5 9.5 9.5 9.5 Tributyl 6 6 6 6 6 acetylcitrate Isopropyl 6 6 6 6 6 alcohol Stearalkonium 1.3 1.3 1.3 1.3 1.3 bentonite Phosphoric 0.03 0.01 0.05 0.1 acid Citric acid 0.03 Sorbic acid 0.1 0.1 0.1 0.1 0.1 Results Yellowing OK OK OK OK OK stability Varnish 248 242 240 240 237 hardness (s) Viscosity (mPa .Math. s)  6 rpm 3250 1400 1890 4090 5630 60 rpm 1020 980 1010 1080 1120  6 rpm 2090 1230 1460 2530 3250 Adhesion 0 0 0 0 0 Stability of Stable Sedimentation Stable Stable Discolora- the shade of the tion of described pearlescent the shade hereinabove agent

[0062] Conclusions:

[0063] Sedimentation is observed in the presence of citric acid in place of phosphoric acid. Phosphoric acid at 0.1% by weight in the varnish discolors the Pigment Red 34.