FOR MAKE-UP OF NAILS

The present invention relates to an adhesive composition based on a volatile hydrocarbon solvent for make-up and/or for care of nails, as well as to its use for make-up and/or care of nails.

The make-up articles for nails such as false nails are commonly used by users for aesthetical reasons. Laying false nails on the nails then requires the use of specific adhesives in order to obtain satisfactory adhesion of the false nail on the nail.

Presently, the adhesives which are found on the market for adhering false nails onto the nails are traditionally based on ethyl cyanoacrylate. Conventionally, ethyl cyanoacrylate is used in association with a polymer such as polymethyl methacrylate, leading to the formation of a very solid polymerized system, as described in US 5,658,415. Nevertheless, this type of adhesive has the drawback of having high adhesion, certainly giving the possibility of very good adhesion of the false nails onto the nails, but in return making them difficult to be removed when desired by the consumer. Further, ethycyanoacrylate has the drawback of being relatively unstable and therefore difficult to convey.

Thus there exists a need for having an adhesive for make-up and/or care of nails giving the possibility of having false nails adhere efficiently on the nails and the physico-chemical properties of which allow facilitated removal.

The object of the present invention is to provide an adhesive composition giving the possibility of adhesively bonding nail make-up articles on the nails and of simply removing them once this is desired by the consumer.

Thus, the present invention relates to an adhesive composition for a nail make-up article comprising:

- at least one polymer selected from the group consisting of block copolymers comprising at least one polystyrene block and at least one poly(ethylene/butylene) block or a polyisoprene block, and

- at least one tackifying resin with a number average molecular weight of less than or equal to 10,000 g/mol, selected from the group consisting of aliphatic hydrocarbon resins,

- at least one plasticizer,

- at least one apolar volatile solvent, and

- at least one polar volatile solvent, wherein the total content of tackifying resin(s) and the total content of polymer(s) as defined earlier are such that a mass ratio between said tackifying resin(s) and said polymer(s) is comprised between 0.5 and 3.

Preferably, the mass ratio between the tackifying resin and the polymer is comprised between 1 and 2. This ratio is favorable for obtaining an adhesive having both satisfactory adhesion and high cohesion.

The adhesive composition, once applied on a substrate, forms an adhesive layer having certain tackiness defined by its viscoelastic properties.

The viscoelastic properties of a material are conventionally defined by two characteristic values which are the following:

- the elastic modulus which represents the elastic behavior of the material for a given frequency and which is conventionally noted as G', and

- the viscous modulus which represents the viscous behavior of the material for a given frequency and which is conventionally noted as G".

These quantities are notably defined in the « Handbook of Pressure Sensitive Adhesive Technology », 3 ^rd Edition, D. Satas, Chapter 9. 155-157.

Preferably, the adhesive materials which may be used according to the present invention have viscoelastic properties which are measured at a reference temperature of 35°C and in a certain range of frequencies.

In the case of adhesive materials in the form of a polymer solution or dispersion in a volatile solvent (such as water, a short-chain ester, a short-chain alcohol, acetone, etc.), the viscoelastic properties of this material are measured under conditions in which it has a volatile solvent content of less than or equal to 30%, and in particular, a volatile solvent content of less than or equal to 20%.

The elastic modulus of the material is in particular measured at three different frequencies:

- at a low frequency, i.e. at 2.10 ^"2 Hz ;

- at an intermediate frequency, i.e. at 0.2 Hz ;

- at high frequency, i.e. at 2 Hz; and

- the viscous modulus at the frequency of 0.2 Hz.

These measurements allow evaluation of the time-dependent change in the tackiness of the adhesive material over time.

These viscoelastic properties are measured during dynamic tests with sinusoidal stresses of low amplitude (small deformations) conducted at 35 °C over a range of frequencies ranging from 2.10 ^"2 to 20 Hz on a rheometer of the « Haake RS50R » type under a torsion/shear stress, for example in a plane-cone geometry (for example with a cone angle of 1 °).

Advantageously, said adhesive material fits the following conditions:

- G'(2 Hz, 35°C)≥ 10 ³ Pa, and

- G'(35°C)< 10 ⁸ Pa, in particular, G'(35°C)< 10 ⁷ Pa,

- G' (2.10 ² Hz, 35°C)< 3.10 ⁵ Pa,

wherein:

- G'(2 Hz, 35 °C) is the elastic shear modulus of sad adhesive material, measured at a frequency of 2 Hz and at a temperature of 35°C,

- G'(35°C) is the elastic shear modulus of said adhesive material measured at a temperature of 35°C, for any frequency comprised between 2.10 ^"2 and 2 Hz,

- G'(2.10 ^~2 Hz, 35°C) is the elastic shear modulus of said adhesive material, measured at the frequency of 2.10 ^"2 Hz and at a temperature of 35 °C.

In a particular embodiment of the invention, the adhesive material also fits the following condition:

- G7G' (0.2 Hz, 35°C)≥0.35

wherein:

- G"(0.2 Hz, 35°C) is the viscous shear modulus of said adhesive material, measured at the frequency of 0.2 Hz and at a temperature of 35 °C,

- G'(0.2 Hz, 35°C) is the elastic shear modulus of said adhesive material measured at a frequency of 0.2 Hz and at a temperature of 35°C.

In a particular embodiment of the invention, one has:

- G'(2 Hz, 35 °C)≥ 5.10 ³ Pa, and in particular G'(2 Hz, 35 °C)≥ 10 ⁴ Pa.

In another particular embodiment of the invention, one has:

- G'(2.10 ^"2 Hz, 35 °C)< 5.10 ⁴ Pa.

In particular, the adhesive materials according to the invention fit the four following conditions:

- G'(2 Hz, 35 °C)≥ 10 ⁴ Pa, and

- G'(35 °C)< 10 ⁸ Pa, in particular G'(35 °C)< 10 ⁷ Pa,

- G'(2.10 ^-2 Hz, 35 °C)< 5.10 ⁴ Pa, and

- G7G'(0.2 Hz, 35 °C)≥0.35.

Block copolymer

According to the invention, the adhesive composition comprises at least one polymer selected from the group consisting of block copolymers comprising at least one polystyrene block and at least one poly(ethylene/butylene) block or a polyisoprene block. This may be a block copolymer alone or a mixture of block copolymers.

Within the present invention, the block copolymers are solid at ambient temperature.

In the sense of the present invention, by "copolymer" it is meant to designate a polymer stemming from at least two types of monomers.

Within the scope of the present invention, the term "block copolymer" (or "block copolymers") designates a copolymer consisting of blocks of different compositions, connected together as linear sequences. These copolymers may also be designated as "sequenced copolymers". Thus, these block copolymers or sequenced copolymers are polymers comprising at least 2 distinct sequences or blocks.

Within the scope of the present invention, block copolymers also encompass diblock, triblock, multiblock, radial or star copolymers.

In particular, the block copolymers consist of at least two blocks, preferably two or three blocks. These copolymers are therefore preferably selected from diblock copolymers or triblock copolymers.

They may for example be illustrated as follows: (block A) (block B) for diblock copolymers and (block A) (block B) (block A) or (block B) (block A) (block B) for triblock copolymers.

According to the invention, multiblock copolymers designate copolymers comprising more than three blocks.

Block copolymers according to the invention may also be selected from star block copolymers or radial block copolymers. These copolymers have a single branching point from which emerge several blocks. In particular, such a star copolymer having n blocks bound to the branching point is called a star copolymer with n blocks (or radial copolymer).

Copolymers may have a linear structure or a non-linear structure such as for example, a copolymer with a branched, radial, star structure. Block copolymers according to the invention may be random or alternating copolymers.

As indicated above, the polymer according to the invention is selected from the group consisting of block copolymers comprising at least one polystyrene block and at least one poly(ethylene/butylene) block or a polyisoprene block.

The polystyrene block, which has some rigidity, gives the possibility of providing cohesion to the adhesive composition.

Examples of such block copolymers are styrene-ethylene/butylene copolymers, styrene-isoprene copolymers, styrene-ethylene/butylene-styrene copolymers and styrene-isoprene-styrene copolymers such as those marketed by KRATON. Advantageously, the polymer is a mixture of block copolymers comprising at least one diblock copolymer and at least one triblock copolymer.

According to an alternative, the polymer is a mixture of linear styrene-ethylene/butylene-styrene triblock copolymers and of styrene-ethylene/butylene diblock copolymers notably available from KRATON under reference KRATON® G1657M (SEBS/SEB).

According to another alternative, the polymer is a mixture of linear styrene-isoprene-styrene triblock copolymers and of styrene-isoprene diblock copolymers notably available from KRATON under reference KRATON® D1 161 (SIS).

Preferably, the polymer contents is from 1 % to 50%, advantageously from 5% to 30%, preferably from 10% to 20%, by weight based on the total weight of the composition.

The block copolymers according to the invention are apolar and thus have good compatibility with the tackifying resins according to the invention, described hereafter, which contributes to the tackiness of the adhesive composition of the invention.

In the sense of the present invention, a compound is described as « apolar » when the positive and negative charges found within this compound are symmetrically distributed.

Tackifying resin

The adhesive composition according to the invention comprises at least one tackifying resin as defined above.

Within the scope of the present description, « tackifying resin » means a thermoplastic resin, with low molecular mass entering the composition of the adhesives.

The tackifying resins according to the invention have a number average molecular weight of less than or equal to 10,000 g/mol.

Advantageously, this number average molecular weight ranges from 250 g/mol to 10,000 g/mol, preferably from 250 g/mol to 5,000 g/mol, more preferentially from 250 g/mol to 2,000 g/mol, or even from 250 g/mol to 1 ,000 g/mol.

The number average molecular weights (Mn) are determined by liquid gel permeation chromatography (THF solvent, calibration curve established with linear polystyrene standards, refractometer detector).

The tackifying resins according to the invention are selected from aliphatic hydrocarbon resins.

As an aliphatic hydrocarbon resin, mention may notably be made of:

- hydrogenated indene/methylstyrene/styrene copolymers marketed under the name of « REGALITE » by Eastman Chemical, in particular REGALITE R1090, REGALITE R1 100, REGALITE S1 100, and REGALITE S5100, or under the name of ARKON P-90, ARKON P-100, and ARKON P-1 15, by Arakawa;

- aliphatic pentanediene resins such as those from the polymerization of a majority of 1 ,3-pentanediene monomers (trans or cis piperylene) and of a minority of monomer selected from isoprene, butane, 2-methyl-2-butene, pentene, 1 ,4-pentanediene, and mixtures thereof. These resins may have a molecular weight ranging from 1 .000 to 2.500 g/mol. Such 1 ,3-pentanediene resins are marketed for example under references PICCOTAC 95 by Eastman Chemical, ESCOREZ 1 102, ESCOREZ 1304, ESCOREZ 1310LC, ESCOREZ 1315 by Exxon Chemicals, WINGTACK 95 by Cray Valley;

- the diene resins of cyclopentanediene dimers such as those from the polymerization of dicyclopentanediene, methyldicyclopentanediene, of other pentanediene dimers, and mixtures thereof. These resins generally have a molecular weight ranging from 500 to 800 g/mol, such as for example those marketed under reference ESCOREZ 5380, ESCOREZ 5300, ESCOREZ 5400, ESCOREZ 5415, ESCOREZ 5490, by Exxon Mobil Chem., and the resins SUKOREZ SU-90, SUKOREZ SU-100, SUKOREZ SU-1 10, SUKOREZ SU-100S, SUKOREZ SU-200, SUKOREZ SU-210, SUKOREZ SU-490, SUKOREZ SU-400, by Kolon;

- hydrogenated resins from the polymerization of pentanediene such as those marketed under the name of EASTOTAC H-100E, EASTOTAC H-1 15E, EASTOTAC C-100L, EASTOTAC C-1 15L, EASTOTAC H-100L, EASTOTAC H-1 15L, EASTOTAC C-100R, EASTOTAC C-1 15R, EASTOTAC H-100R, EASTOTAC H-1 15R, EASTOTAC C-100W, EASTOTAC C-1 15W, EASTOTAC H-100W, EASTOTAC H-1 15W, by Eastman Chemical Co.;

and mixtures thereof.

The tackifying resin is for example the hydrogenated indene/methylstyrene/styrene copolymer marketed under the name of REGALITE R1090 by Eastman Chemical, or further the aliphatic 1 ,3-pentanediene resin marketed under the name of PICCOTAC 1095 by Eastman Chemical.

Preferably, the tackifying resin content is from 5% to 50%, preferably from 10% to 30%, by weight based on the total weight of the composition.

Plasticizer

According to the invention, the adhesive composition comprises at least one plasticizer. The adhesive composition of the invention comprises at least one plasticizer chosen from the group consisting of: liquid paraffins, polyisobutenes, either hydrogenated or not hydrogenated, and mixtures thereof. In the sense of the present invention, by « plasticizer » is meant a compound in a more or less viscous liquid state, which, added to a formulation of a given material, allows it to become tackier, more adherent, more flexible, more resistant and/or easier to handle.

The adhesive composition of the invention may also comprise at least one further plasticizer. Among these plasticizers, mention may notably be made of customary plasticizers such as glycols and their derivatives, such as diethylene glycol ethylether, diethylene glycol methylether, diethylene glycol butylether or further diethylene glycol hexylether, ethylene glycol ethylether, ethylene glycol methylether, ethylene glycol butylether, ethylene glycol hexylether, glycol esters, derivatives of propylene glycol and in particular propylene glycol phenylether, propylene glycol diacetate, dipropylene glycol butylether, tripropylene glycol butylether, propylene glycol methylether, dipropylene glycol ethylether, tripropylene glycol methylether and diethylene glycol methylether, propylene glycol butylether, esters of notably carboxylic acids, such as citrates, notably trimethyl citrate, tributyl citrate, trimethyl acetylcitrate, tributyl acetylcitrate, triethyl-2-hexyl acetylcitrate, phthalates, notably dimethoxyethyl phthalate; phosphates notably tricresyl phosphate, tributyl phosphate, triphenyl phosphate, tributoxyethyl phosphate, tartrates notably dibutyl tartrate; adipates, carbonates, sebacates; benzyl benzoate, butyl acetylricinoleate, glyceryl acetylricinoleate, butyl glycolate, camphor, glycerol triacetate, N- ethyl-o,p-toluenesulfonamide, oxyethylene derivatives such as oxyethylene oils, notably vegetable oils, such as castor oil, silicone oils, hydrocarbon oils, and mixtures thereof. Advantageously, the plasticizer is selected from non-volatile hydrocarbon oils.

By « non-volatile oil », is meant an oil or a solvent which remains on the nails at room temperature and at atmospheric pressure for at least several hours and notably having a vapor pressure of less than or equal to 10 ^"3 mm of Hg (0.13 Pa).

For example the plasticizer marketed under the name of PRIMOL 352 by EXXON

MOBIL is used.

According to the invention, the plasticizer content is from 1 % to 15%, and is preferably from 1 % to 7%, by weight based on the total weight of the composition. Volatile solvents

A composition according to the invention includes at least one apolar volatile solvent and at least one polar volatile solvent.

In the sense of the present invention, by « volatile solvent » is meant a solvent or an oil, which may evaporate in contact with keratinic materials in less than one hour, at room temperature of 25 °C and at atmospheric pressure. The volatile solvents of the invention are volatile organic solvents, liquid at room temperature, having non-zero vapor pressure, at room temperature and at atmospheric pressure, in particular from 0.13 Pa to 40,000 Pa (10 ^~3 to 300 mm of Hg), advantageously from 1 .3 Pa to 13,000 Pa (0.01 to 100 mm of Hg), preferably from 1 .3 Pa to 1 ,300 Pa (0.01 to 10 mm of Hg).

By « apolar solvent », in the sense of the present invention is meant a solvent or an oil for which the solubility parameter at 25 °C, 5 _a , is equal to 0 (J/cm ³ ) ^½ .

The definition and the calculation of the solubility parameters in the HANSEN three-dimensional solubility space are described in the article of C. M. HANSEN : "The three-dimensional solubility parameters" J. Paint Technol. 39, 105 (1967).

According to this Hansen space:

- 5 _D characterizes the LONDON dispersion forces stemming from the formation of dipoles induced during molecular impacts;

- δ _ρ characterizes the DEBYE interaction forces between permanent dipoles as well as the KEESOM interaction forces between induced dipoles and permanent dipoles;

- 5 _h characterizes the specific interaction forces (hydrogen, acid/base, donor/acceptor bonds, etc. type); and

- 5a is determined by the equation: 5 _a = (δ _ρ ² + 5 _h ² ) ^½ .

The parameters δ _ρ , 5 _h , 5 _D and 5 _a are expressed in (J/cm ³ ) ^½ .

By « polar solvent », in the sense of the present invention is meant a solvent, or an oil, for which the solubility parameter calculated beyond its melting point 5 _a is different from 0 (J/cm ³ ) ^½ .

In particular, by « polar » solvent, is meant a solvent for which the chemical structure is essentially formed, or even consists of, carbon and hydrogen atoms, and comprising at least one strongly electronegative heteroatom such as an oxygen, nitrogen, silicon or phosphorus atom.

The definition and the calculation of the solubility parameters are as defined earlier.

Apolar volatile solvents

A composition according to the invention includes at least one solvent, or an apolar volatile oil.

Preferably, this apolar volatile solvent is selected from apolar volatile C ₄ -C ₉ solvents, in particular apolar volatile C ₄ -C ₉ hydrocarbon solvents.

As an apolar volatile C ₄ -C ₉ hydrocarbon solvent, mention may be made notably of pentane, hexane, cyclohexane, heptane and isoparaffinic C ₈ -C ₉ hydrocarbons notably available from ExxonMobil Chemical under reference ISOPAR. Advantageously, the apolar volatile hydrocarbon solvent is a C ₆ -C ₇ hydrocarbon solvent, preferable selected from the group consisting of hexane, cyclohexane, heptane, and mixtures thereof.

The volatile hydrocarbon solvent is for example cyclohexane.

Polar volatile solvents.

Moreover, an adhesive composition according to the invention comprises at least one polar volatile solvent.

Preferably, this polar volatile solvent is selected from the group consisting of C ₃ -C ₆ ketones and esters, and mixtures thereof.

As a polar volatile solvent, mention may notably be made of acetone, methylethylketone, methylisobutylketone, cyclohexanone and alkyl acetates in which the alkyl group comprises from 2 to 5 carbon atoms, such as methyl acetate, ethyl acetate, propyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate and tert-butyl acetate.

Preferably, the polar volatile solvent is a C ₃ -C ₅ solvent, and more preferentially selected from the group consisting of ethyl acetate, n-propyl acetate, isopropyl acetate, and mixtures thereof.

The polar volatile solvent is for example ethyl acetate.

The polar volatile solvent alone cannot solubilize the whole of the constituents of the adhesive composition of the invention, but adding an apolar volatile solvent as defined above gives the possibility of getting rid of this difficulty.

Both types of solvent preferentially have a short carbon chain length, at the origin of their volatility.

According to an embodiment, the apolar volatile solvent is cyclohexane and the polar volatile solvent is ethyl acetate.

Generally, the total content of polar and apolar volatile solvent(s) is of at least 40%, advantageously from 50% to 90%, preferably from 60% to 75% by weight based on the total weight of the composition.

Additives

The adhesive composition may further comprise other ingredients commonly used in cosmetic compositions and known to one skilled in the art as being able to be incorporated into an adhesive composition for a nail make-up article.

Such ingredients may be selected from pigments and coloring agents, plasticizers, coalescence agents, preservatives, oils, waxes, agents against free radicals, spreading agents, wetting agents, dispersant agents, antifoam agents, preservatives, surfactants, perfumes, neutralizers, stabilizers, antioxidants, thickeners, wherein the actives may be selected from essential oils, UV/solar screens, moisturizing agents, vitamins, proteins, ceramides, vegetable extracts, etc., and mixtures thereof.

The composition according to the invention may further comprise as actives, nail care agents such as hardening agents for keratinic materials, actives acting on the growth of the nail such as for example methyl sulfonyl methane and/or actives for treating diverse affections localized at the nail, such as for example onichomycosis.

Of course, one skilled in the art will make sure that this (these) optional complementary compound(s) and/or their amount will be selected so that the advantageous properties of the composition for the use according to the invention are not or substantially not altered by the contemplated addition.

The present invention finally relates to, or comprises the application of the adhesive composition as described earlier.

More specifically, it relates to a method for make-up and/or care of nails comprising:

a) a step consisting of applying on the surface of the nail at least one layer of an adhesive composition according to the invention, in order to obtain a coated nail,

b) a step consisting of applying under the surface of an article for make-up of nails at least one layer of the composition according to the invention, in order to obtain a coated article for make-up of nails,

c) a step consisting of putting said coated article for make-up of nails, obtained at the end of step b), in contact with said coated nail obtained at the end of step a), in order to obtain a nail covered with a nail make-up article.

Typically, the nail make-up article is a false nail.

Preferably, the method comprises a step for drying the layers of adhesive composition before applying the nail make-up article on the nail.

More specifically, the consumer coats the surface of his/her nails with at least one adhesive composition layer as described earlier, and does the same under the surface of the false nails which he/she wishes to stick. Once applied, both adhesive composition layers typically dry for a few seconds to a few minutes and the consumer applies the false nails coated with dry adhesive composition onto his/her nails also coated with dry adhesive composition. His/her nails are thus covered with false nails which are held satisfactorily. Finally, the present invention also aims at a method for removing make-up from nails covered with nail make-up articles via such an adhesive composition.

More specifically this is a method for removing make-up from a nail covered with a nail make-up article which may be obtained by a method as described above, comprising the removal of said nail make-up article from said nail by peeling it off.

More particularly, the consumer may remove a false nail stuck on a nail by means of the adhesive composition of the invention, by pulling on the false nail and the adhesive layer consisting of adhesive composition located between the nail and the false nail. The removal of make-up from the nail is therefore facilitated as compared with the case when the false nail is stuck in a conventional way, by means of the physico-chemical properties of the adhesive composition of the invention.

The weight percentages given in this application may be assimilated to the percentage by weight of dry material of the applied compounds.

The terms « comprise(s) one » or « include(s) one » should be understood as the following « comprise(s) at least one » or « include(s) at least one », unless explicitly specified otherwise.

The invention will be better understood upon reading the description which follows only given as an example.

EXAMPLES

Example 1.1 : Preparation of an adhesive composition C1 according to the invention

An adhesive composition C1 according to the invention was prepared as follows: The constituents of the composition C1 , indicated in Table 1 , were mixed and heated to 45°C while stirring with the magnetized rod until a homogeneous mixture was obtained.

Table 1

Example 1.2: Method for make-up of nails comprising the use of the adhesive composition C1

The adhesive composition 01 (Example 1 .1 ) was coated on the nails, as well as under false nails bearing the reference « EDGE FASHION NAILS » of the FING'RS® brand. After drying the adhesive layers, the coated false nails were applied on the coated nails.

The thereby obtained make-up of the nails was able to be easily removed by peeling it off. Example 2.1 : Preparation of an adhesive composition C2 according to the invention.

An adhesive composition C2 according to the invention was prepared as follows.

The constituents of the composition C2, indicated in Table 2, were mixed and heated at 45°C while stirring with the magnetized rod until a homogeneous mixture was obtained.

Table 2

Example 2.2: Make-up method for nails comprising the use of the adhesive composition C2.

The adhesive composition C2 (Example 2.1 ) was coated on the nails, as well as under the false nails, bearing the reference « EDGE FASHION NAILS » of the FING'RS® brand. After drying the adhesive layers, the coated false nails were applied on the coated nails.

The thereby obtained make-up of the nails may be easily removed by peeling it off.

Comparative Example 1.1 : Preparation of an adhesive composition CP1 comprising an aliphatic/aromatic hydrocarbon tackifying resin.

The constituents of the composition CP1 , indicated in Table 3 were mixed and heated to 45°C while stirring with the magnetized rod until a homogeneous mixture was obtained. Table 3

This adhesive composition comprises an aliphatic/aromatic hydrocarbon tackifying resin, different from the tackifying resins of the invention.

Comparative example 1 :2: Make-up method for nails comprising the use of the adhesive composition CP1 .

The adhesive composition CP1 (Comparative example 1 .1 ) was coated on the nails, as well as under the false nails bearing the reference « EDGE FASHION NAILS » of the FING'RS® brand. After drying the adhesive layers, the coated false nails are applied on the coated nails.

The obtained make-up of the nails does not properly adhere to the nails. The thereby obtained adhesive layer has tackiness upon touching after drying which is smaller than in the case of Examples 1 .2 and 2.2.