WO2011067807A1 - Cosmetic composition containing fusiform particles for cosmetic use - Google Patents

Abstract

Cosmetic composition for making up and/or caring for keratinous substances comprising, in a physiologically acceptable medium, at least: a) one ethylenic block copolymer comprising at least one first block having a glass transition temperature (Tg) of greater than or equal to 40 degrees centigrade and resulting, in all or in part, from one or more first monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of greater than or equal to 40 degrees centigrade and at least one second block having a glass transition temperature of less than or equal to 20 degrees centigrade and resulting, in all or in part, from one or more second monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of less than or equal to 20 degrees centigrade, the said first block and the said second block being connected to one another via a random intermediate segment comprising at least one of the said first constituent monomers of the first block and at least one of the said second constituent monomers of the second block and the said block copolymer having a polydispersity index I of greater than 2, b) at least one nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol; and c) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometer, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometer, and L₁/L₂ between approximately 1.1 and approximately 3.3; the said composition comprising less than 10% by weight of volatile oil having a flash point of less than or equal to 80 degrees centigrade, with respect to the total weight of the composition.

Description

COSMETIC COMPOSITION CONTAINING FUSIFORM PARTICLES FOR COSMETIC USE

A subject-matter of the present invention is a cosmetic composition for making up and/or caring for keratinous substances, in particular the lips. The present invention relates in particular for cosmetic composition which contains particles having a non (hemi) spherical shape such as a fusiform shape, also named a 'rugby ball' shape according to the invention.

Background

Such compositions for making up and/or for caring for the skin and/or lips conventionally comprise a film-forming polymer known for improving the hold during the time of these compositions on keratinous substances and in particular, where a lipstick is concerned, the hold of the said lipstick on the lips.

However, such film-forming polymers are generally conveyed in volatile oils (it being possible for the latter to be used, for example, as polymerization solvent for the film-forming polymer) which can present feelings of discomfort on application and can be harmful to the gloss of the deposited layer of lipstick. Furthermore, the presence of this volatile oil, when present in a large amount (that is to say greater than 10% by weight with respect to the total weight of the composition), involves constraints in terms of the preparation process, in particular for the preparation of lipsticks comprising solid fatty substances, such as waxes, having a high melting point, for which it is necessary to heat to a temperature generally greater than that of the flash point of the volatile oil.

Furthermore, these compositions comprising a volatile oil have to be packaged in a packaging in order to protect from any evaporation of the solvent (that is to say of the volatile oil) from the composition during storage. This constraint on the packaging represents an additional cost.

The documents EP 1 411 069 and EP 1 882 709 disclose cosmetic compositions comprising block polymers conveyed in a volatile oil having a flash point of less than 80 degrees centigrade (such as, for example, isododecane).

These block polymers are in particular synthesized in the presence of isododecane. In point of fact, the block polymer, conveyed in a volatile oil having a flash point of less than 80 degrees centigrade, such as Isododecane or Cyclopolydimethylsiloxane, can only be formulated with cosmetic additives not requiring a stage of heating at a temperature greater than that of the flash point of the said volatile oil.

Thus, for example, the introduction of a solid fatty substance, such as a wax or a pasty fatty substance, exhibiting a flash point greater than the said flash point of the said volatile oil cannot be carried out; this is because it would be necessary to heat the mixture of polymer, volatile oil and solid fatty substance to a temperature greater than the flash point of the said volatile solvent.

In addition, the presence of a large amount of volatile oil having a flash point of less than 80 degrees centigrade is harmful to good cosmetic properties being obtained for a cosmetic composition to be applied to the lips or skin. This is because a high content (that is to say of greater than 10%) of volatile oil brings about a feeling of dryness and tightness on the lips or skin (feeling of discomfort) and a reduction in the gloss of the deposited layer formed immediately after application of the composition to the lips or skin, or after 1 hour after application.

The need thus exists to have available a cosmetic composition comprising a film-forming block polymer which makes it possible to obtain a deposited layer on the lips or skin exhibiting good properties of gloss and comfort (immediately after application and during the time (particularly one hour after application).

There is another need also to further improve the properties such as feel, smoothness and easiness to applied, particularly on the lips or the skin, at application and wearing and tolerability of gloss and comfort.

The inventors have discovered that such a composition can be obtained by combining the film-forming block polymer, specific nonvolatile ester oils and fusiform particles.

Such a composition, provides a lubricious and smooth feel at application to keratinous substances, in particular the skin or lips, and makes it possible to obtain a good quality deposited layer (homogenous, and easy to apply), in particular of makeup, exhibiting good properties of comfort (absence of feeling of tightness or of dryness) and of gloss, after application and after at least 1 hour.

This composition also makes it possible to obtain a makeup for keratinous substances (skin and lips in particular) exhibiting a good hold of the colour and make-up results, that is to say that the deposit of the compositions remains homogeneous, and is not fragilized during that time.

Thus, according to a first aspect, a subject-matter of the present invention is a cosmetic composition for making up and/or caring for keratinous substances, in particular the lips or skin, comprising, in a physiologically acceptable medium, at least:
a) one ethylenic block copolymer comprising at least one first block having a glass transition temperature (Tg) of greater than or equal to 40 degrees centigrade and resulting, in all or in part, from one or more first monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of greater than or equal to 40 degrees centigrade and at least one second block having a glass transition temperature of less than or equal to 20 degrees centigrade and resulting, in all or in part, from one or more second monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of less than or equal to 20 degrees centigrade, the said first block and the said second block being connected to one another via a random intermediate segment comprising at least one of the said first constituent monomers of the first block and at least one of the said second constituent monomers of the second block and the said block copolymer having a polydispersity index I of greater than 2;
b) one nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol; and
c) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometer, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometer, and L₁/L₂ between approximately 1.1 and approximately 3.3;
the said composition comprising less than 10% by weight of volatile oils having a flash point of less than or equal to 80 degrees centigrade (such as isododecane), or better still less than 5% by weight, with respect to the total weight of the composition, or even being devoid of volatile oils having a flash point of less than or equal to 80 degrees centigrade and less than 50% by weight of the fusiform particles.

Another subject-matter of the invention, according to another aspect, is a cosmetic method for making up keratinous substances comprising the application, to the said keratinous substances and in particular the lips, of a composition as defined above.

Finally, a subject-matter of the invention is the use of a block copolymer as described above, in combination with at least one nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol, in a composition comprising less than 10% or better still less than 5% or even being devoid of volatile oils having a flash point of less than or equal to 80 degrees centigrade (such as isododecane) and the fusion particles as described above, the composition being intended to provide a lubricious smooth feel at application and a deposited layer on keratinous substances, in particular the lips, exhibiting properties of comfort, of gloss and, advantageously, of hold of the gloss, having a lengthy hold.

The use of this combination has the advantage of providing a film of an increased cosmetic quality.
In the context of the present invention, the term "keratinous substances" comprises the skin, lips, nails, hair, eyelashes and eyebrows.
According to a first embodiment, the composition according to the invention is solid.
According to a second embodiment, the composition according to the invention is liquid.
The terms "solid" and "liquid" characterize the state of the composition at ambient temperature (25 degrees centigrade) and at atmospheric pressure (760 mmHg).

The fusiform particles as well as the methods for obtaining the fusiform particles are described, for example, in the Japanese Patent Application, Publication No. 2003-171465 filed by Takemoto Fat & Oil.

A fusiform or 'rugby ball' shape in this specification refers to such a shape that a sphere is extended in one direction so that there is a major axis along which the fusiform particle has the largest diameter L₁ which is between approximately 0.05 micrometer and approximately 20 micrometer and two minor axes L₂ perpendicular to the major axis and to each other along which the fusiform particle has the smallest diameter which is between approximately 0.03 micrometer and approximately 15 micrometer, and L₁/L₂ between approximately 1.1 and approximately 3.3.

In a particular embodiment, the fusiform particles have slits along their major axes. According to the present invention, the fusiform particles may preferably be between approximately 0.5 wt% and approximately 50 wt%, preferably approximately 0.5 wt% and approximately 10 wt%, more preferably between approximately 0.5 wt% and approximately 3 wt% of the composition.

Protocol for measuring the hardness
The measurement is carried out according to the following protocol:
The lipstick stick is stored at 20 degrees centigrade for 24 hours before measuring the hardness.
The hardness can be measured at 20 degrees centigrade by the "cheesewire" method, which consists in transversely cutting a stick of product, preferably a cylindrical stick generated by rotation, using a stiff tungsten wire with a diameter of 250 micrometer, the wire being moved relative to the stick at a rate of 100 mm/min.

The hardness of the samples of compositions of the invention, expressed in Nm^-1, is measured using a DFGS2 force gauge sold by Indelco Chatillon.
The measurement is repeated three times and then averaged. The mean of the three values read using the force gauge mentioned above, denoted Y, is given in grams. This mean is converted to newtons and then divided by L, which represents the greatest dimension traversed by the wire. In the case of a cylindrical stick, L is equal to the diameter (in metres).

The hardness is converted into Nm^-1 by the following equation:
(Y x 10^-3 x 9.8)/L
For a measurement at a different temperature, the stick is stored at this new temperature for 24 hours before the measurement.
According to this method, the hardness at 20 degrees centigrade of examples with a composition according to one aspect of the invention is greater than 30 Nm^-1, in particular greater than 40 Nm^-1, preferably greater than 50 Nm^-1.

According to this method, the hardness at 20 degrees centigrade of examples with a composition according to one aspect of the invention is less than 500 Nm^-1, in particular less than 400 Nm^-1, preferably less than 300 Nm^-1.
In particular, the term "solid composition" is understood to mean a composition having a hardness of greater than 30 Nm^-1.

ETHYLENIC BLOCK COPOLYMER
The composition according to the present invention comprises at least one ethylenic block copolymer (also known as block ethylenic polymer) comprising at least one first block having a glass transition temperature (Tg) of greater than or equal to 40 degrees centigrade and resulting, in all or in part, from one or more first monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of greater than or equal to 40 degrees centigrade and at least one second block having a glass transition temperature of less than or equal to 20 degrees centigrade and resulting, in all or in part, from one or more second monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of less than or equal to 20 degrees centigrade, the said first block and the said second block being connected to one another via a random intermediate segment comprising at least one of the said first constituent monomers of the first block and at least one of the said second constituent monomers of the second block and the said block copolymer having a polydispersity index I of greater than 2.

The block polymer used according to the invention thus comprises at least one first block and at least one second block.
The term "at least" one block is understood to mean one or more blocks.
The term "block" polymer is understood to mean a polymer comprising at least two distinct blocks, preferably at least three distinct blocks.
The term "ethylenic" polymer is understood to mean a polymer obtained by polymerization of monomers comprising an ethylenic unsaturation.
The block ethylenic polymer used according to the invention is prepared exclusively from monofunctional monomers.

This means that the block ethylenic polymer used according to the present invention does not comprise polyfunctional monomers which make it possible to break the linearity of a polymer in order to obtain a branched or indeed even crosslinked polymer, depending on the level of polyfunctional monomer. Neither does the polymer used according to the invention comprise macromonomers (the term "macromonomer" is understood to mean a monofunctional monomer having a pendant group of polymeric nature and preferably having a molecular weight of greater than 500 g/mol or else a polymer comprising, on only one of its ends, a polymerizable end group (or an end group comprising ethylenic unsaturation)), which are used for the preparation of a grafted polymer.

It is specified that, in that which precedes and that which follows, the terms "first" and "second" blocks do not in any way condition the order of the said blocks (or sequences) in the structure of the polymer.
The first block and the second block of the polymer used in the invention can advantageously be incompatible with one another.

The term "blocks incompatible with one another" is understood to mean that the blend formed by a polymer corresponding to the first block and by a polymer corresponding to the second block is immiscible in the polymerization solvent, predominant by weight, for the block polymer, at ambient temperature (25 degrees centigrade) and atmospheric pressure (10⁵ Pa), for a content of the blend of the said polymers of greater than or equal to 15% by weight, with respect to the total weight of the blend of the said polymers and of the said polymerization solvent, it being understood that:
i) the said polymers are present in the blend in a content such that the respective ratio by weight ranges from 10/90 to 90/10, and that
ii) each of the polymers corresponding to the first and second blocks has a (weight- or number)average molecular weight equal to that of the block polymer + or - 15%.

In the case of a mixture of polymerization solvents, in the event of two or more solvents present in identical proportions by weight, the said blend of polymers is immiscible in at least one of them.
Of course, in the case of a polymerization carried out in a single solvent, the latter is the predominant solvent.

The block polymer according to the invention comprises at least one first block and at least one second block connected to one another via an intermediate segment comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block. The intermediate segment (also called intermediate block) has a glass transition temperature Tg between the glass transition temperatures of the first and second blocks.

The intermediate segment is a block comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block of the polymer which makes it possible to "compatibilize" these blocks.

Advantageously, the intermediate segment, comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block of the polymer, is a random polymer.

Preferably, the intermediate block results essentially from constituent monomers of the first block and of the second block.
The term "essentially" is understood to mean at least to 85%, preferably at least to 90%, better still to 95% and even better still to 100%.

The block polymer according to the invention is advantageously a film-forming ethylenic block polymer.
The term "ethylenic" polymer is understood to mean a polymer obtained by polymerization of monomers comprising an ethylenic unsaturation.

The term "film-forming" polymer is understood to mean a polymer capable of forming, by itself alone or in the presence of an additional agent which is able to form a film, a continuous deposited layer on a support, in particular on keratinous substances.

Preferably, the polymer according to the invention does not comprise silicon atoms in its backbone. The term "backbone" is understood to mean the main chain of the polymer, in contrast to pendant side chains.

Preferably, the polymer according to the invention is water-insoluble, that is to say that the polymer is insoluble in water or in a mixture of water and of linear or branched lower monoalcohols having from 2 to 5 carbon atoms, such as ethanol, isopropanol or n-propanol, without modification of pH, at an active material content of at least 1% by weight, at ambient temperature (25 degrees centigrade).

Preferably, the polymer according to the invention is not an elastomer.
The term "nonelastomeric polymer" is understood to mean a polymer which, when it is subjected to a stress targeted at drawing it (for example by 30%, relative to its initial length), does not return to a length substantially identical to its initial length when the stress is discontinued.

More specifically, the term "nonelastomeric polymer" denotes a polymer having an instantaneous recovery R_i < 50% and a delayed recovery R_2h < 70% after having undergone an elongation of 30%. Preferably, R_i is < 30% and R_2h < 50%.

More specifically, the nonelastomeric nature of the polymer is determined according to the following protocol:
A polymer film is prepared by casting a solution of the polymer in a Teflon-treated matrix and then drying for 7 days in surroundings controlled at 23 + or - 5 degrees centigrade and 50 + or - 10% relative humidity.
A film with a thickness of approximately 100 micrometer is then obtained, from which rectangular test specimens with a width of 15 mm and a length of 80 mm are cut out (for example with a hole punch).
A tensile stress is applied to this sample using a device sold under the Zwick reference, under the same temperature and humidity conditions as for the drying.
The test specimens are drawn at a rate of 50 mm/min and the distance between the clamping jaws is 50 mm, which corresponds to the initial length (I₀) of the test specimen.

The instantaneous recovery R_i is determined in the following way:
- the test specimen is drawn by 30% (E_max), that is to say approximately 0.3 times its initial length (I₀)
- the stress is released by applying a return rate equal to the tensioning rate, i.e. 50 mm/min, and the residual elongation of the test specimen is measured as a percentage, after returning to zero loading stress (E_i).

The instantaneous recovery in % (R_i) is given by the formula below:
R_i = ((E_max-E_i)/E_max)x 100

To determine the delayed recovery, the residual elongation of the test specimen is measured as a percentage (E_2h), 2 hours after returning to the zero loading stress.

The delayed recovery in % (R_2h)is given by the formula below:
R_2h = ((E_max-E_2h)/E_max)x 100

Purely by way of indication, a polymer according to one embodiment of the invention preferably has an instantaneous recovery R_i of 10% and a delayed recovery R_2h of 30%.

The polydispersity index of the polymer of the invention is greater than 2.
Advantageously, the block polymer used in the compositions according to the invention has a polydispersity index I of greater than 2, for example ranging from 2 to 9, preferably of greater than or equal to 2.5, for example ranging from 2.5 to 8, and better still of greater than or equal to 2.8, in particular ranging from 2.8 to 6.

The polydispersity index I of the polymer is equal to the ratio of the weight-average molar mass Mw to the number-average molar mass Mn.

The weight-average molar masses (Mw) and the number-average molar masses (Mn) are determined by gel permeation liquid chromatography (solvent THF, calibration curve drawn up with linear polystyrene standards, refractometric detector).

The weight-average molar mass (Mw) of the polymer according to the invention is preferably less than or equal to 300 000 g/mol; it ranges, for example, from 35 000 to 200 000 g/mol and better still from 45 000 to 150 000 g/mol.

The number-average molar mass (Mn) of the polymer according to the invention is preferably less than or equal to 70 000 g/mol; it ranges, for example, from 10 000 to 60 000 g/mol and better still from 12 000 to 50 000 g/mol.

Preferably, the polydispersity index of the polymer according to the invention is greater than 2, for example ranging from 2 to 9, preferably greater than or equal to 2.5, for example ranging from 2.5 to 8, and better still greater than or equal to 2.8, in particular ranging from 2.8 to 6.

First block having a Tg of greater than or equal to 40 degrees centigrade
The block having a Tg of greater than or equal to 40 degrees centigrade has, for example, a Tg ranging from 40 to 150 degrees centigrade, preferably of greater than or equal to 50 degrees centigrade, for example ranging from 50 degrees centigrade to 120 degrees centigrade, and better still of greater than or equal to 60 degrees centigrade, for example ranging from 60 degrees centigrade to 120 degrees centigrade.

The glass transition temperatures indicated for the first and second blocks can be theoretical Tg values determined from the theoretical Tg values of the constituent monomers of each of the blocks, which can be found in a reference handbook, such as the Polymer Handbook, 3rd ed., 1989, John Wiley, according to the following relationship, referred to as the Fox law:

omega_i being the fraction by weight of the monomer i in the block under consideration and Tg_i being the glass transition temperature of the homopolymer of the monomer i.

Unless otherwise indicated, the Tg values indicated for the first and second blocks in the present patent application are theoretical Tg values.
The difference between the glass transition temperatures of the first and second blocks is generally greater than 10 degrees centigrade, preferably greater than 20 degrees centigrade and better still greater than 30 degrees centigrade.

In the present invention, the expression "of between ... and ..." is intended to denote a range of values, the limits of which mentioned are excluded, and the expressions "from ... to ..." and "ranging from ... to ..." are intended to denote a range of values, the limits of which are included.

The block having a Tg of greater than or equal to 40 degrees centigrade can be a homopolymer or copolymer.
The block having a Tg of greater than or equal to 40 degrees centigrade can result, in all or in part, from one or more monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of greater than or equal to 40 degrees centigrade. This block can also be referred to as "rigid block".

In the case where this block is a homopolymer, it results from monomers which are such that the homopolymers prepared from these monomers have glass transition temperatures of greater than or equal to 40 degrees centigrade. This first block can be a homopolymer composed of just one type of monomer (the Tg of the corresponding homopolymer of which is greater than or equal to 40 degrees centigrade).

In the case where the first block is a copolymer, it can result, in all or in part, from one or more monomers, the natures and the concentrations of which are chosen so that the Tg of the resulting copolymer is greater than or equal to 40 degrees centigrade. The copolymer can, for example, comprise:
- monomers which are such that the homopolymers prepared from these monomers have Tg values of greater than or equal to 40 degrees centigrade, for example a Tg ranging from 40 degrees centigrade to 150 degrees centigrade, preferably of greater than or equal to 50 degrees centigrade, for example ranging from 50 degrees centigrade to 120 degrees centigrade, and better still of greater than or equal to 60 degrees centigrade, for example ranging from 60 degrees centigrade to 120 degrees centigrade, and
- monomers which are such that the homopolymers prepared from these monomers have Tg values of less than 40 degrees centigrade, chosen from monomers having a Tg of between 20 degrees centigrade and 40 degrees centigrade and/or monomers having a Tg of less than or equal to 20 degrees centigrade, for example a Tg ranging from -100 degrees centigrade to 20 degrees centigrade, preferably of less than 15 degrees centigrade, in particular ranging from -80 degrees centigrade to 15 degrees centigrade, and better still of less than 10 degrees centigrade, for example ranging from -50 degrees centigrade to 0 degrees centigrade, as described below.

The first monomers, the homopolymers of which have a glass transition temperature of greater than or equal to 40 degrees centigrade, are preferably chosen from the following monomers, also known as main monomers:
- methacrylates of formula CH₂=C(CH₃)-COOR₁
in which R₁ represents a linear or branched unsubstituted alkyl group comprising from 1 to 4 carbon atoms, such as the methyl, ethyl, propyl or isobutyl group, or R₁ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl group, such as isobornyl,
- acrylates of formula CH₂=CH-COOR₂
in which R₂ represents a C₄ to C₁₂ cycloalkyl group, such as an isobornyl group, or a tert-butyl group,
- (meth)acrylamides of formula:

where R₇ and R₈, which are identical or different, each represent a hydrogen atom or a linear or branched C₁ to C₁₂ alkyl group, such as an n-butyl, t-butyl, isopropyl, isohexyl, isooctyl, or isononyl group; or R₇ represents H and R₈ represents a 1,1-dimethyl-3-oxobutyl group,
and R' denotes H or methyl. Mention may be made, as examples of monomers, of N-butylacrylamide, N-(t-butyl)acrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide and N,N-dibutylacrylamide,
- and their mixtures.

The first block is advantageously obtained from at least one acrylate monomer of formula CH₂=CH-COOR₂ and from at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR₂ in which R₂ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl group, such as isobornyl. The monomers and their proportions are preferably chosen so that the glass transition temperature of the first block is greater than or equal to 40 degrees centigrade.

According to one embodiment, the first block is obtained from:
i) at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl group, such as isobornyl,
ii) and at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₄ to C₁₂ cycloalkyl group, preferably a C₈ to C₁₂ cycloalkyl group, such as isobornyl.

According to one embodiment, the first block is obtained from at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₈ to C₁₂ cycloalkyl group, such as isobornyl, and from at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₈ to C₁₂ cycloalkyl group, such as isobornyl.

Preferably, R₂ and R'₂ represent, independently or simultaneously, an isobornyl group.
Preferably, the block copolymer comprises from 50 to 80% by weight of isobornyl methacrylate/acrylate, from 10 to 30% by weight of isobutyl acrylate and from 2 to 10% by weight of acrylic acid.

The first block can be obtained exclusively from the said acrylate monomer and from the said methacrylate monomer.
The acrylate monomer and the methacrylate monomer are preferably in proportions by weight of between 30:70 and 70:30, preferably between 40:60 and 60:40, in particular of the order of 50:50.

The proportion of the first block advantageously ranges from 20 to 90% by weight of the polymer, better still from 30 to 80% by weight and even better still from 60 to 80% by weight.

According to one embodiment, the first block is obtained by polymerization of isobornyl methacrylate and isobornyl acrylate.

Second block with a glass transition temperature of less than 20 degrees centigrade
The second block advantageously has a glass transition temperature Tg of less than or equal to 20 degrees centigrade, for example a Tg ranging from -100 degrees centigrade to 20 degrees centigrade, preferably of less than or equal to 15 degrees centigrade, in particular ranging from -80 degrees centigrade to 15 degrees centigrade, and better still of less than or equal to 10 degrees centigrade, for example ranging from -100 degrees centigrade to 10 degrees centigrade, in particular ranging from -30 degrees centigrade to 10 degrees centigrade.

The second block results, in all or in part, from one or more second monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of less than or equal to 20 degrees centigrade.

This block can also be referred to as "flexible block".
The monomer having a Tg of less than or equal to 20 degrees centigrade (referred to as second monomer) is preferably chosen from the following monomers:
- acrylates of formula CH₂=CHCOOR₃,
R₃ representing an unsubstituted linear or branched C₁ to C₁₂ alkyl group, with the exception of the tert-butyl group, in which is(are) optionally inserted one or more heteroatoms chosen from O, N and S,
- methacrylates of formula CH₂=C(CH₃)-COOR₄,
R₄ representing an unsubstituted linear or branched C₆ to C₁₂ alkyl group in which is(are) optionally inserted one or more heteroatoms chosen from O, N and S;
- vinyl esters of formula R₅-CO-O-CH=CH₂,
where R₅ represents a linear or branched C₄ to C₁₂ alkyl group;
- C₄ to C₁₂ alkyl vinyl ethers,
- N-(C₄ to C₁₂ alkyl)acrylamides, such as N-octylacrylamide,
- and their mixtures.

The preferred monomers having a Tg of less than or equal to 20 degrees centigrade are isobutyl acrylate, 2-ethylhexyl acrylates or their mixtures in all proportions.
Each of the first and second blocks can comprise a minor proportion of at least one constituent monomer of the other block.
Thus, the first block can comprise at least one constituent monomer of the second block and vice versa.

Each of the first and/or second blocks can comprise, in addition to the monomers indicated above, one or more other monomers, known as additional monomers, other than the main monomers mentioned above.

The nature and the amount of this or these additional monomers are chosen so that the block in which they occur has the desired glass transition temperature.

This additional monomer is, for example, chosen from:
- monomers having ethylenic unsaturation(s) comprising at least one tertiary amine functional group, such as 2-vinylpyridine, 4-vinylpyridine, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminopropylmethacrylamide and the salts of these,
- methacrylates of formula CH₂=C(CH₃)-COOR₆
in which R₆ represents a linear or branched alkyl group comprising from 1 to 4 carbon atoms, such as a methyl, ethyl, propyl or isobutyl group, the said alkyl group being substituted by one or more substituents chosen from hydroxyl groups (such as 2-hydroxypropyl methacrylate or 2-hydroxyethyl methacrylate) and halogen atoms (Cl, Br, I, F), such as trifluoroethyl methacrylate,
- methacrylates of formula CH₂=C(CH₃)-COOR₉,
R₉ representing a linear or branched C₆ to C₁₂ alkyl group in which is(are) optionally inserted one or more heteroatoms chosen from O, N and S, the said alkyl group being substituted by one or more substituents chosen from hydroxyl groups and halogen atoms (Cl, Br, I, F);
- acrylates of formula CH₂=CHCOOR₁₀,
R₁₀ representing a linear or branched C₁ to C₁₂ alkyl group substituted by one or more substituents chosen from hydroxyl groups and halogen atoms (Cl, Br, I and F), such as 2-hydroxypropyl acrylate and 2-hydroxyethyl acrylate, or R₁₀ representing a (C₁ to C₁₂ alkyl)-O-POE (polyoxyethylene) with repetition of the oxyethylene unit from 5 to 10 times, for example methoxy-POE, or R₁₀ representing a polyoxyethylene group comprising from 5 to 10 ethylene oxide units.

In particular, the first block can comprise, as additional monomer:
- (meth)acrylic acid, preferably acrylic acid,
- tert-butyl acrylate,
- methacrylates of formula CH₂=C(CH₃)-COOR₁
in which R₁ represents a linear or branched unsubstituted alkyl group comprising from 1 to 4 carbon atoms, such as a methyl, ethyl, propyl or isobutyl group,
- (meth)acrylamides of formula:

where R₇ and R₈, which are identical or different, each represent a hydrogen atom or a linear or branched C₁ to C₁₂ alkyl group, such as an n-butyl, t-butyl, isopropyl, isohexyl, isooctyl, or isononyl group; or R₇ represents H and R₈ represents a 1,1-dimethyl-3-oxobutyl group,
and R' denotes H or methyl. Mention may be made, as examples of monomers, of N-butylacrylamide, N-(t-butyl)acrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide and N,N-dibutylacrylamide,
- and their mixtures.

The additional monomer can represent from 0.5 to 30% by weight of the weight of the polymer. According to one embodiment, the polymer of the invention does not comprise an additional monomer.

Preferably, the polymer of the invention comprises at least isobornyl acrylate and isobornyl methacrylate monomers in the first block and isobutyl acrylate and acrylic acid monomers in the second block.

Preferably, the polymer comprises at least isobornyl acrylate and isobornyl methacrylate monomers in an equivalent proportion by weight in the first block and isobutyl acrylate and acrylic acid monomers in the second block.

Preferably, the polymer comprises at least isobornyl acrylate and isobornyl methacrylate monomers in an equivalent proportion by weight in the first block and isobutyl acrylate and acrylic acid monomers in the second block, the first block representing 70% by weight of the polymer.

Preferably, the polymer comprises at least isobornyl acrylate and isobornyl methacrylate monomers in an equivalent proportion by weight in the first block and isobutyl acrylate and acrylic acid monomers in the second block. Preferably, the block with a Tg of greater than 40 degrees centigrade represents 70% by weight of the polymer and the acrylic acid represents 5% by weight of the polymer.

According to one embodiment, the first block does not comprise an additional monomer.
According to a preferred embodiment, the second block comprises acrylic acid as additional monomer. In particular, the second block is advantageously obtained from an acrylic acid monomer and from at least one other monomer having a Tg of less than or equal to 20 degrees centigrade.

According to a preferred embodiment, the invention relates to a cosmetic composition for making up and/or caring for keratinous substances comprising, in a physiologically acceptable medium, at least one copolymer comprising at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₈ to C₁₂ cycloalkyl group and/or at least one methacrylate monomer of the formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₈ to C₁₂ cycloalkyl group, at least one second acrylate monomer of formula CH₂=CHCOOR₃ in which R₃ represents an unsubstituted linear or branched C₁ to C₁₂ alkyl group, with the exception of the tert-butyl group, and at least one acrylic acid monomer, the said composition additionally comprising at least one nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol and the said composition comprising less than 10% by weight of volatile oil having a flash point of less than or equal to 80 degrees centigrade, with respect to the total weight of the composition.

Preferably, the copolymer used in the compositions according to the invention is obtained from at least one isobornyl methacrylate monomer, at least one isobornyl acrylate monomer, at least one isobutyl acrylate monomer and at least one acrylic acid monomer.

Advantageously, the copolymer used in the invention comprises from 50 to 80% by weight of isobornyl methacrylate/acrylate mixture, from 10 to 30% by weight of isobutyl acrylate and from 2 to 10% by weight of acrylic acid.

The block copolymer can advantageously comprise more the 2% by weight of acrylic acid monomers and in in particular from 2 to 15% by weight, for example from 3 to 15% by weight, especially from 4 to 15% by weight, indeed even from 4 to 10% by weight, of acrylic acid monomers, with respect to the total weight of the said copolymer.

The constituent monomers of the second block and their proportions are chosen so that the glass transition temperature of the second block is less than or equal to 20 degrees centigrade.

Intermediate segment
The intermediate segment (also referred to as intermediate block) connects the first block and the second block of the polymer used according to the present invention.

The intermediate segment results from the polymerization;
i) of the first monomer or monomers, and optionally of the additional monomer or monomers, remaining available after their polymerization to a degree of conversion of at most 90%, in order to form the first block,
ii) and of the second monomer or monomers, and optionally of the additional monomer or monomers, added to the reaction mixture.

The formation of the second block is initiated when the first monomers no longer react or are no longer incorporated in the polymer chain, either because they are all consumed or because their reactivity no longer allows them to be consumed.
Thus, the intermediate segment comprises the available first monomers, resulting from a degree of conversion of these first monomers of less than or equal to 90%, during the introduction of the second monomer or monomers during the synthesis of the polymer.

The intermediate segment of the block polymer is a random polymer (may also be referred to as a random block), that is to say that it comprises a random distribution of the first monomer or monomers and of the second monomer or monomers and also of the additional monomer or monomers optionally present.

Thus, the intermediate segment is a random block, just like the first block and the second block, if they are not homopolymers (that is to say, if they are both formed from at least two different monomers).

Process for the preparation of the copolymer
The ethylenic block copolymer according to the invention is prepared by free radical polymerization according to the well-known techniques of this type of polymerization.

The free radical polymerization is carried out in the presence of an initiator, the nature of which is adjusted, in a known way, according to the polymerization temperature desired and the polymerization solvent. In particular, the initiator can be chosen from initiators comprising a peroxide functional group, oxidation/reduction couples or other radical polymerization initiators known to a person skilled in the art.

In particular, mention may be made, as initiator comprising a peroxide functional group, for example, of:
a. peroxyesters, such as tert-butyl peroxyacetate, tert-butyl perbenzoate, tert-butyl peroxy(2-ethylhexanoate) (Trigonox 21S from Akzo Nobel) or 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane (Trigonox 141 from Akzo Nobel);
b. peroxydicarbonates, such as diisopropyl peroxydicarbonate;
c. peroxyketones, such as methyl ethyl ketone peroxide;
d. hydroperoxides, such as aqueous hydrogen peroxide solution (H₂O₂) or tert-butyl hydroperoxide;
e. diacyl peroxides, such as acetyl peroxide or benzoyl peroxide;
f. dialkyl peroxides, such as di(tert-butyl) peroxide;
g. inorganic peroxides, such as potassium peroxodisulphate (K₂S₂O₈).

Mention may be made, as initiator in the form of an oxidation/reduction couple, of the potassium thiosulphate + potassium peroxodisulphate couple, for example.

According to a preferred embodiment, the initiator is chosen from organic peroxides comprising from 8 to 30 carbon atoms. Preferably, the initiator used is 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, sold under the reference Trigonox(R) 141 by Akzo Nobel.

The block copolymer used according to the invention is prepared by free radical polymerization and not by controlled or living polymerization. In particular, the polymerization of the ethylenic block copolymer is carried out in the absence of control agents and in particular in the absence of control agents conventionally used in living or controlled polymerization processes, such as nitroxides, alkoxyamines, dithioesters, dithiocarbamates, dithiocarbonates or xanthates, trithiocarbonates or copper-based catalysts, for example.

As indicated above, the intermediate segment is a random block, just like the first block and the second block, if they are not homopolymers (that is to say, if they are both formed from at least two different monomers).

The block copolymer can be prepared by free radical polymerization and in particular by a process which consists in mixing, in one and the same reactor, a polymerization solvent, an initiator, at least one monomer with a glass transition of greater than or equal to 40 degrees centigrade and at least one monomer with a glass transition of less than or equal to 20 degrees centigrade, according to the following sequence:
- a portion of the polymerization solvent and optionally a portion of the initiator and monomers of the first fluid addition are run into the reactor, which mixture is heated to a reaction temperature of between 60 and 120 degrees centigrade,
- the said at least one first monomer with a Tg of greater than or equal to 40 degrees centigrade and optionally a portion of the initiator are subsequently run in, in a first fluid addition, and are left to react for a time T corresponding to a degree of conversion of the said monomers of at most 90%,
- again polymerization initiator and the said at least one second monomer with a glass transition of less than or equal to 20 degrees centigrade are subsequently run into the reactor, in a second fluid addition, and are left to react for a time T', at the end of which the degree of conversion of the said monomers reaches a plateau,
- the reaction mixture is brought back to ambient temperature.

Preferably, the copolymer can be prepared by free radical polymerization, in particular by a process which consists in mixing, in one and the same reactor, a polymerization solvent, an initiator, an acrylic acid monomer, at least one monomer with a glass transition of less than or equal to 20 degrees centigrade, at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₄ to C₁₂ cycloalkyl group and at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₄ to C₁₂ cycloalkyl group, according to the following sequence of stages:
- a portion of the polymerization solvent and optionally a portion of the initiator and monomers of the first fluid addition are run into the reactor, which mixture is heated to a reaction temperature of between 60 and 120 degrees centigrade,
- the said at least acrylate monomer of formula CH₂=CH-COOR₂ and the said at least methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂, as monomers with a Tg of greater than or equal to 40 degrees centigrade, and optionally a portion of the initiator are subsequently run in, in a first fluid addition, and are left to react for a time T corresponding to a degree of conversion of the said monomers of at most 90%,
- again polymerization initiator, the acrylic acid monomer and the said at least monomer with a glass transition of less than or equal to 20 degrees centigrade are subsequently run into the reactor, in a second fluid addition, and are left to react for a time T', at the end of which the degree of conversion of the said monomers reaches a plateau,
- the reaction mixture is brought back to ambient temperature.

The term polymerization solvent is understood to mean a solvent or a mixture of solvents. Mention may in particular be made, as polymerization solvent which can be used, of:
- ketones which are liquid at ambient temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone or acetone;
- propylene glycol ethers which are liquid at ambient temperature, such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate or dipropylene glycol mono(n-butyl) ether;
- short-chain esters (having a total of 3 to 8 carbon atoms), such as ethyl acetate, methyl acetate, propyl acetate, n-butyl acetate or isopentyl acetate;
- ethers which are liquid at ambient temperature, such as diethyl ether, dimethyl ether or dichlorodiethyl ether;
- alkanes which are liquid at ambient temperature, such as decane, heptane, dodecane, isododecane, cyclohexane or isohexadecane;
- cyclic aromatic compounds which are liquid at ambient temperature, such as toluene and xylene; aldehydes which are liquid at ambient temperature, such as benzaldehyde or acetaldehyde, and their mixtures.

Conventionally, the polymerization solvent is a volatile oil with a flash point of less than 80 degrees centigrade. The flash point is measured in particular according to Standard ISO 3679.
The polymerization solvent can be chosen in particular from ethyl acetate, butyl acetate, alcohols, such as isopropanol or ethanol, aliphatic alkanes, such as isododecane, and their mixtures. Preferably, the polymerization solvent is a mixture of butyl acetate and isopropanol or isododecane.

According to another embodiment, the copolymer can be prepared by free radical polymerization according to a preparation process which consists in mixing, in one and the same reactor, a polymerization solvent, an initiator, at least one monomer with a glass transition of less than or equal to 20 degrees centigrade and at least one monomer with a Tg of greater than or equal to 40 degrees centigrade, according to the following sequence of stages:
- a portion of the polymerization solvent and optionally a portion of the initiator and monomers of the first fluid addition are run into the reactor, which mixture is heated to a reaction temperature of between 60 and 120 degrees centigrade,
- the said at least one monomer with a glass transition of less than or equal to 20 degrees centigrade and optionally a portion of the initiator are subsequently run in, in a first fluid addition, and are left to react for a time T corresponding to a degree of conversion of the said monomers of at most 90%,
- again polymerization initiator and the said at least one monomer with a Tg of greater than or equal to 40 degrees centigrade are subsequently run into the reactor, in a second fluid addition, and are left to react for a time T', at the end of which the degree of conversion of the said monomers reaches a plateau,
- the reaction mixture is brought back to ambient temperature.

According to a preferred embodiment, the copolymer can be prepared by free-radical polymerization according to a preparation process which consists in mixing, in one and the same reactor, a polymerization solvent, an initiator, an acrylic acid monomer, at least one monomer with a glass transition of less than or equal to 20 degrees centigrade and at least one monomer with a Tg of greater than or equal to 40 degrees centigrade, in particular, as monomers with a Tg of greater than or equal to 40 degrees centigrade, at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₄ to C₁₂ cycloalkyl group and at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₄ to C₁₂ cycloalkyl group, according to the following sequence of stages:
- a portion of the polymerization solvent and optionally a portion of the initiator and monomers of the first fluid addition are run into the reactor, which mixture is heated to a reaction temperature of between 60 and 120 degrees centigrade,
- the acrylic acid monomer and the said at least monomer with a glass transition of less than or equal to 20 degrees centigrade and optionally a portion of the initiator are subsequently run in, in a first fluid addition, and are left to react for a time T corresponding to a degree of conversion of the said monomers of at most 90%,
- again polymerization initiator, the said at least one acrylate monomer of formula CH₂=CH-COOR₂ and the said at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂, as monomers with a Tg of greater than or equal to 40 degrees centigrade, are subsequently run into the reactor, in a second fluid addition, and are left to react for a time T', at the end of which the degree of conversion of the said monomers reaches a plateau,
- the reaction mixture is brought back to ambient temperature.

The polymerization temperature is preferably of the order of 90 degrees centigrade.
The reaction time after the second fluid addition is preferably between 3 and 6 hours.

Distillation of the synthesis solvent
For the use of the block polymer in a composition according to the invention and when the polymer is prepared in a volatile solvent or a volatile oil having a flash point of less than 80 degrees centigrade, it is necessary to proceed to a stage of complete or partial removal of the said volatile solvent or oil. The operation is carried out in particular by distillation, optionally under vacuum, and addition of nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol.
This technique is known to a person skilled in the art and is illustrated in Example 2, described below.

The distillation of the synthesis solvent (conventionally isododecane) is carried out with simultaneous addition or in the presence in the mixture before the distillation of a nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol. This stage is carried out under hot conditions and optionally under vacuum in order to distil the maximum amount of isododecane (and more generally of synthesis solvent), if the latter was used as polymerization solvent, or more generally in order to distil the maximum amount of volatile oil having a flash point of less than 80 degrees centigrade. The nonvolatile ester oil can also be added, in part or completely, to the polymer in the volatile solvent before the distillation.

The removal of the volatile oil with a flash point of less than 80 degrees centigrade (conventionally isododecane) makes it possible to limit the content of the latter in the block copolymer solution and thus to produce a cosmetic composition comprising less than 10% by weight of isododecane (and more generally of volatile solvent) and preferably less than 5% by weight of isododecane (and more generally of volatile solvent), with respect to the total weight of the composition.

The composition according to the invention preferably comprises less than 0.5 to 40% by weight of ethylenic block copolymer and advantageously from 1 to 40% by weight, in particular from 2 to 30% by weight, indeed even from 2 to 20% by weight, of active material, with respect to the total weight of the composition.

Nonvolatile hydrocarbon ester oil
The composition according to the invention comprises a nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol.
The term "oil" is understood to mean a nonaqueous compound which is liquid at ambient temperature (25 degrees centigrade) and atmospheric pressure (760 mmHg).

The term "nonvolatile oil" is understood to mean an oil which remains on keratinous substances at ambient temperature and atmospheric pressure for at least several hours and which has in particular a vapour pressure of less than 10^-3 mmHg (0.13 Pa). A nonvolatile oil can also be defined as having a rate of evaporation such that, under the conditions defined above, the amount evaporated at the end of 30 minutes is less than 0.07 mg/cm.

The term "hydrocarbon oil" is understood to mean an oil formed essentially, indeed even composed, of carbon and hydrogen atoms and optionally of oxygen and nitrogen atoms and which does not comprise a silicon or fluorine atom. The term "hydrocarbon ester oil" is understood to mean a hydrocarbon oil comprising at least one ester group.

The presence or the addition of the nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol makes it possible in particular to replace via the distillation and thus to limit the content in the composition of (indeed even to dispense completely with) the volatile oil or oils having a flash point of less than or equal to 80 degrees centigrade, in particular those which have been used as polymerization solvent, especially such as isododecane. Specifically, these volatile oils are commonly used as polymerization solvent for the copolymers present in the composition and, as is indicated above, produce a feeling of discomfort, of dryness and/or of tightness on the lips and in addition impose constraints in terms of process for the preparation of the composition, in particular when the formulator wishes to add, to the latter, starting materials requiring that the composition be heated, in particular if it is necessary to heat to a temperature greater than the flash point of the polymerization solvent, and the volatile oils are also the cause of constraints in terms of packaging, the latter then having to be leaktight.

Mention may in particular be made, as nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol, of:
- esters of a fatty acid, in particular of 4 to 22 carbon atoms and especially of octanoic acid, heptanoic acid, lanolic acid, oleic acid, lauric acid or stearic acid, such as propylene glycol dioctanoate, propylene glycol monoisostearate or neopentyl glycol diheptanoate,
- synthetic esters, such as oils of formula R₁COOR₂ in which R₁ represents the residue of a linear or branched fatty acid comprising from 4 to 40 carbon atoms and R₂ represents a hydrocarbon chain, in particular a branched hydrocarbon chain, comprising from 4 to 40 carbon atoms, provided that R₁ + R₂ is greater or equal 16, such as, for example, Purcellin oil (cetearyl octanoate), isononyl isononanoate, C₁₂ to C₁₅ alkyl benzoate, 2-ethylhexyl palmitate, octyldodecyl neopentanoate, 2-octyldodecyl stearate, 2-octyldodecyl erucate, isostearyl isostearate, 2-octyldodecyl benzoate, octanoates, decanoates or ricinoleates of alcohols or polyalcohols, isopropyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, 2-ethylhexyl palmitate, 2-hexyldecyl laurate, 2-octyldecyl palmitate, 2-octyldodecyl myristate or di(2-ethylhexyl) succinate; preferably, the preferred synthetic esters R₁COOR₂ in which R₁ represents the residue of a linear or branched fatty acid comprising from 4 to 40 carbon atoms and R₂ represents a hydrocarbon chain, in particular a branched hydrocarbon chain, comprising from 4 to 40 carbon atoms are such that R₁ and R₂ is greater or equal 20;
- hydroxylated esters, such as isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, glyceryl stearate or diethylene glycol diisononanoate; and
- pentaerythritol esters or esters of aromatic acids and of alcohols comprising from 4 to 22 carbon atoms, in particular tridecyl trimellitate.

According to one embodiment, the nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol does not carry a free hydroxyl (OH) group.
According to a preferred embodiment, the nonvolatile hydrocarbon ester oil comprises at least 20 carbon atoms and has a molar mass of less than 650 g/mol.
According to a preferred embodiment, the nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms has a molar mass of less than 600 g/mol.

The nonvolatile hydrocarbon ester oil can in particular comprise a linear or branched hydrocarbon oil having a molar mass of between 100 and 650 g/mol and more particularly between 200 and 600 g/mol.
This is because the choice of these nonvolatile oils makes it possible to optimize the amount of volatile oil having a flash point of less than or equal to 80 degrees centigrade evaporated, that is to say to distil most of the polymerization solvent (such as isododecane), indeed even essentially all the polymerization solvent (that is to say, volatile oil having a flash point of less than or equal to 80 degrees centigrade), the latter remaining in the composition only in the form of traces.

The use of other solvents does not make it possible to sufficiently remove volatile oil having a flash point of less than or equal to 80 degrees centigrade. During the distillation, the mixture becomes very viscous and impossible to handle, and it is no longer possible to continue the distillation.

According to a preferred embodiment, the nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms (preferably at least 20 carbon atoms) and having a molar mass of less than 650 g/mol is octyldodecyl neopentanoate (in particular 2-octyldodecyl neopentanoate). This is because this ester oil makes it possible to distil all of the volatile oil having a flash point of less than or equal to 80 degrees centigrade.

The composition according to the invention can comprise from 2 to 80% by weight of nonvolatile oil, in particular from 5 to 70% by weight of nonvolatile oil, with respect to the total weight of the composition. According to a preferred embodiment, the ratio by weight of ethylenic block copolymer with respect to the weight of nonvolatile hydrocarbon ester oil is less than 1, preferably less than 0.75 or better still less than 0.5.

Additional nonvolatile oil
The composition according to the invention can advantageously comprise at least one other additional nonvolatile oil other than the said hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol.

This additional oil can be chosen from all cosmetically acceptable oils, in particular mineral, vegetable or synthetic oils; in particular volatile or nonvolatile hydrocarbon and/or silicone and/or fluorinated oils and their mixtures.
Within the meaning of the present invention, the term "silicone oil" is understood to mean an oil comprising at least one silicon atom and in particular at least one Si-O group.

The term "fluorinated oil" is understood to mean an oil comprising at least one fluorine atom.
More specifically, the term "hydrocarbon oil" is understood to mean an oil formed mainly, indeed even composed, of carbon and hydrogen atoms, which does not comprise a silicon or fluorine atom and which optionally comprises one or more functional groups chosen from hydroxyl, ester, ether or carboxyl functional groups.

Mention may be made, as an example of additional nonvolatile hydrocarbon oil, of:
1) linear or branched hydrocarbons of mineral or synthetic origin, such as:
- liquid paraffin or its derivatives,
- liquid petrolatum,
- polybutylenes, such as Indopol H-100 (with a molar mass or MW=965 g/mol), Indopol H-300 (MW=1340 g/mol) or Indopol H-1500 (MW=2160 g/mol), sold or manufactured by Amoco,
- hydrogenated polyisobutylenes, such as Parleam(R), sold by Nippon Oil Fats, Panalane H 300 E, sold or manufactured by Amoco (MW=1340 g/mol), Viseal 20000, sold or manufactured by Synteal (MW=6000 g/mol), or Rewopal PIB 1000, sold or manufactured by Witco (MW=1000 g/mol),
- polydecenes and hydrogenated polydecenes, such as: Puresyn 10 (MW=723 g/mol) or Puresyn 150 (MW=9200 g/mol), sold or manufactured by Mobil Chemicals,

2) vinylpyrrolidone copolymers, such as: the vinylpyrrolidone/1-hexadecene copolymer Antaron V 216, sold or manufactured by ISP (MW=7300 g/mol),

3) hydrocarbon ester oils having a molar mass of greater than 650 g/mol, such as:
- esters of linear fatty acids having a total carbon number ranging from 35 to 70, such as pentaerythrityl tetrapelargonate (MW=697 g/mol),
- hydroxylated esters, such as polyglycerol-2 triisostearate (MW=965 g/mol),
- aromatic esters, such as tridecyl trimellitate (MW=757 g/mol),
- C₂₄-C₂₈ branched fatty acid or fatty alcohol esters, such as those described in Application EP-A-0 955 039 and in particular triisoarachidyl citrate (MW=1033.76 g/mol), pentaerythrityl tetraisononanoate (MW=697 g/mol), glyceryl triisostearate (MW=891 g/mol), glyceryl tri(2-decyltetradecanoate) (MW=1143 g/mol), pentaerythrityl tetraisostearate (MW=1202 g/mol), polyglyceryl-2 tetraisostearate (MW=1232 g/mol) or pentaerythrityl tetra(2-decyltetra-decanoate) (MW=1538 g/mol),
- a polyester resulting from the esterification of at least one triglyceride of hydroxylated carboxylic acid(s) by an aliphatic monocarboxylic acid and by an aliphatic dicarboxylic acid which is optionally unsaturated, such as the succinic acid and isostearic acid castor oil sold under the reference Zenigloss by Zenitech,
- esters resulting from the esterification of a polyol and of a dimer diacid, such as polyglyceryl-2 isostearate/dimer dilinoleate copolymer (Hailucent IDSA),
- esters of dimer diol and of dimer diacid of general formula HO-R¹-(-OCO-R²-COO-R¹-)_h-OH, in which:
R¹ represents a dimer diol residue, which dimer diol is obtained by hydrogenation of dilinoleic diacid,
R² represents a hydrogenated dilinoleic diacid residue, and
h represents an integer varying from 1 to 9,
in particular the esters of dilinoleic diacids and of dilinoleyl dimer diols sold by Nippon Fine Chemical under the trade names Lusplan DD-DA5(R) and DD-DA7(R), phytosteryl isostearyl dimer dilinoleate (Lusplan PI-DA or Lusplan PHY/IS-DA).
- hydrogenated rosinate esters, such as dimer dilinoleyl hydrogenated rosinate (Lusplan DD-DHR or DD-DHR from Nippon Fine Chemical).

4) silicone oils, such as phenylated silicones (also known as phenylated silicone oil), such as Belsil PDM 1000 from Wacker (MW=9000 g/mol), phenyl trimethicones (such as the phenyl trimethicone sold under the trade name DC556 by Dow Corning), phenyl dimethicones, phenyl(trimethylsiloxy)diphenylsiloxanes, diphenyl dimethicones, diphenyl(methyldiphenyl)trisiloxanes, nonvolatile polydimethylsiloxanes (PDMSs), or polydimethylsiloxanes comprising pendent alkyl or alkoxy groups and/or alkyl or alkoxy groups at the end of the silicone chain, which groups each have from 2 to 24 carbon atoms;

5) oils of vegetable origin, such as sesame oil (MW=820 g/mol),
- and their mixtures.

Preferably, the composition according to the invention advantageously comprises from 1 to 80% by weight, in particular from 5 to 70% by weight and preferably from 10 to 65% by weight of nonvolatile additional oil, with respect to the total weight of the composition.

Oils having a flash point of less than or equal to 80 degrees centigrade
The composition comprises less than 10% by weight of volatile oil having a flash point of less than or equal to 80 degrees centigrade or better still less than 5% by weight, with respect to the total weight of the composition, or is even devoid of volatile oil having a flash point of less than or equal to 80 degrees centigrade, such as isododecane.
The flash point is in particular measured according to Standard ISO 3679.

The term "volatile oil" is understood to mean, within the meaning of the invention, an oil capable of evaporating on contact with keratinous substances in less than one hour at ambient temperature and atmospheric pressure (760 mmHg). The volatile organic solvent or solvents and the volatile oils of the invention are volatile cosmetic organic solvents and oils which are liquid at ambient temperature and which have a nonzero vapour pressure, at ambient temperature and atmospheric pressure, ranging in particular from 0.13 Pa to 40 000 Pa (10^-3 to 300 mmHg), in particular ranging from 1.3 Pa to 13 000 Pa (0.01 to 100 mmHg) and more particularly ranging from 1.3 Pa to 1300 Pa (0.01 to 10 mmHg).

These oils can be hydrocarbon oils, silicone oils, fluorinated oils or their mixtures.
Mention may in particular be made, as volatile oil having a flash point of less than or equal to 80 degrees centigrade, of:
volatile hydrocarbon oils, such as hydrocarbon oils having from 8 to 14 carbon atoms, in particular branched C₈-C₁₄ alkanes, such as C₈-C₁₄ isoalkanes of petroleum origin (also known as isoparaffins), such as isododecane (also known as 2,2,4,4,6-pentamethylheptane), isodecane and, for example, the oils sold under the Isopar or Permetyl trade names, and their mixtures. Preferably, the volatile solvent is chosen from volatile hydrocarbon oils having from 8 to 14 carbon atoms and their mixtures.

Mention may also be made, as other volatile hydrocarbon oils having a flash point of less than or equal to 80 degrees centigrade, of ketones which are liquid at ambient temperature, such as methyl ethyl ketone or acetone; short-chain esters (having a total of 3 to 8 carbon atoms) such as ethyl acetate, methyl acetate, propyl acetate or n-butyl acetate; ethers which are liquid at ambient temperature, such as diethyl ether, dimethyl ether or dichlorodiethyl ether; or linear or branched lower alcohols and in particular monoalcohols having from 2 to 5 carbon atoms, such as ethanol, isopropanol or n-propanol.

According to one embodiment, the composition according to the invention comprises at least one volatile oil having a flash point of greater than 80 degrees centigrade, such as isohexadecane.

2. Solid fatty substances
Advantageously, the composition according to the invention comprises at least one pasty fatty substance or one wax.

Pasty fatty substances
The term "pasty fatty substances" (also known as pasty fatty substances) within the meaning of the present invention is understood to mean a lipophilic fatty compound with a reversible solid/liquid change in state which exhibits, in the solid state, an anisotropic crystalline arrangement and which comprises, at a temperature of 23 degrees centigrade, a liquid fraction and a solid fraction.

In other words, the starting melting point of the pasty compound can be less than 23 degrees centigrade. The liquid fraction of the pasty compound, measured at 23 degrees centigrade, can represent from 9 to 97% by weight of the compound. At 23 degrees centigrade, this liquid fraction preferably represents between 15 and 85% by weight, more preferably between 40 and 85% by weight.

Within the meaning of the invention, the melting point corresponds to the temperature of the most endothermic peak observed by thermal analysis (DSC) as described in Standard ISO 11357-3; 1999. The melting point of a pasty substance or of a wax can be measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name "MDSC 2920" by TA Instruments.

The measurement protocol is as follows:
A 5 mg sample of pasty substance or of wax (according to the circumstances) placed in a crucible is subjected to a first rise in temperature ranging from -20 degrees centigrade to 100 degrees centigrade at a heating rate of 10 degrees centigrade/minute, is then cooled from 100 degrees centigrade to -20 degrees centigrade at a cooling rate of 10 degrees centigrade/minute and, finally, is subjected to a second rise in temperature ranging from -20 degrees centigrade to 100 degrees centigrade at a heating rate of 5 degrees centigrade/minute. During the second rise in temperature, the variation in the difference in power absorbed by the empty crucible and by the crucible comprising the sample of pasty substance or of wax is measured as a function of the temperature. The melting point of the compound is the value of the temperature corresponding to the tip of the peak of the curve representing the variation in the difference in power absorbed as a function of the temperature.

The liquid fraction by weight of the pasty compound at 23 degrees centigrade is equal to the ratio of the enthalpy of fusion consumed at 23 degrees centigrade to the enthalpy of fusion of the pasty compound.
The enthalpy of fusion of the pasty compound is the enthalpy consumed by the compound to change from the solid state to the liquid state. The pasty compound is "in the solid state" when the whole of its mass is in the solid crystalline form. The pasty compound is "in the liquid state" when the whole of its mass is in the liquid form.

The enthalpy of fusion of the pasty compound is equal to the area under the curve of the thermogram obtained using a differential scanning calorimeter (DSC), such as the calorimeter sold under the name MDSC 2920 by TA Instruments, with a rise in temperature of 5 or 10 degrees centigrade per minute, according to Standard ISO 11357-3:1999. The enthalpy of fusion of the pasty compound is the amount of energy necessary to change the compound from the solid state to the liquid state. It is expressed in J/g.

The enthalpy of fusion consumed at 23 degrees centigrade is the amount of energy absorbed by the sample to change from the solid state to the state which it exhibits at 23 degrees centigrade, composed of a liquid fraction and of a solid fraction.

The liquid fraction of the pasty compound measured at 32 degrees centigrade preferably represents from 30 to 100% by weight of the compound, preferably from 50 to 100% by weight of the compound, more preferably from 60 to 100% by weight of the compound. When the liquid fraction of the pasty compound measured at 32 degrees centigrade is equal to 100%, the temperature of the end of the melting range of the pasty compound is less than or equal to 32 degrees centigrade.

The liquid fraction of the pasty compound measured at 32 degrees centigrade is equal to the ratio of the enthalpy of fusion consumed at 32 degrees centigrade to the enthalpy of fusion of the pasty compound. The enthalpy of fusion consumed at 32 degrees centigrade is calculated in the same way as the enthalpy of fusion consumed at 23 degrees centigrade.

The pasty compound is preferably chosen from synthetic compounds and compounds of vegetable origin. A pasty compound can be obtained by synthesis from starting compounds of vegetable origin.

The pasty compound is advantageously chosen from:
- lanolin and its derivatives
- polyol ethers chosen from ethers of pentaerythritol and of polyalkylene glycol, ethers of fatty alcohol and of sugar, and their mixtures. the ether of pentaerythritol and of polyethylene glycol comprising 5 oxyethylene (5 OE) units (CTFA name: PEG-5 Pentaerythrityl Ether), the ether of pentaerythritol and of polypropylene glycol comprising 5 oxypropylene (5 OP) units (CTFA name: PPG-5 Pentaerythrityl Ether), and their mixtures and more particularly the PEG-5 pentaerythrityl ether, PPG-5 pentaerythrityl ether and soybean oil mixture sold under the name "Lanolide" by Vevy, in which mixture the constituents occur in a ratio by weight of 46/46/8: 46% PEG-5 pentaerythrityl ether, 46% PPG-5 pentaerythrityl ether and 8% soybean oil.
- polymeric or nonpolymeric silicone compounds,
- polymeric or nonpolymeric fluorinated compounds,
- vinyl polymers, in particular:
= olefin homopolymers and copolymers,
= hydrogenated diene homopolymers and copolymers,
= linear or branched and homo- or copolymeric oligomers of alkyl (meth)acrylates preferably having a C₈-C₃₀ alkyl group,
= homo- and copolymeric oligomers of vinyl esters having C₈-C₃₀ alkyl groups,
= homo- and copolymeric oligomers of vinyl ethers having C₈-C₃₀ alkyl groups,
- fat-soluble polyethers resulting from polyetherification between one or more C₂-C₁₀₀ diols, preferably C₂-C₅₀ diols,
- esters,
- and/or their mixtures.

The pasty compound is preferably a polymer, in particular a hydrocarbon polymer.
Preference is given, among fat-soluble polyethers, in particular to copolymers of ethylene oxide and/or of propylene oxide with long-chain C₆-C₃₀ alkylene oxides, more preferably such that the ratio by weight of the ethylene oxide and/or of the propylene oxide to the alkylene oxides in the copolymer is from 5:95 to 70:30. Mention will in particular be made, in this family, of the copolymers such that the long-chain alkylene oxides are positioned in blocks having an average molecular weight of 1000 to 10 000, for example a polyoxyethylene/polydodecyl glycol block copolymer, such as the ethers of dodecanediol (22 mol) and of polyethylene glycol (45 OE) sold under the Elfacos ST9 brand by Akzo Nobel.

Preference is given, among esters, in particular to:
- the esters of an oligomeric glycerol, in particular the esters of diglycerol, especially the condensates of adipic acid and of glycerol, for which a portion of the hydroxyl groups of the glycerols have reacted with a mixture of fatty acids, such as stearic acid, capric acid, stearic acid and isostearic acid and 12-hydroxystearic acid, such as, in particular, those sold under the Softisan 649 brand by Sasol,
- the arachidyl propionate sold under the Waxenol 801 brand by Alzo,
- phytosterol esters,
- triglycerides of fatty acids and their derivatives,
- pentaerythritol esters,
- noncrosslinked polyesters resulting from the polycondensation between a linear or branched C₄-C₅₀ dicarboxylic acid or polycarboxylic acid and a C₂-C₅₀ diol or polyol,
- ester aliphatic esters resulting from the esterification of an aliphatic hydroxycarboxylic acid ester by an aliphatic carboxylic acid. Preferably, the aliphatic carboxylic acid comprises from 4 to 30 and preferably from 8 to 30 carbon atoms. It is preferably chosen from hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, hexyldecanoic acid, heptadecanoic acid, octadecanoic acid, isostearic acid, nonadecanoic acid, eicosanoic acid, isoarachidic acid, octyldodecanoic acid, heneicosanoic acid, docosanoic acid and their mixtures.

The aliphatic carboxylic acid is preferably branched. The aliphatic hydroxycarboxylic acid ester advantageously results from a hydroxylated aliphatic carboxylic acid comprising from 2 to 40 carbon atoms, preferably from 10 to 34 carbon atoms and better still from 12 to 28 carbon atoms and from 1 to 20 hydroxyl groups, preferably from 1 to 10 hydroxyl groups and better still from 1 to 6 hydroxyl groups.

The aliphatic hydroxycarboxylic acid ester is chosen from:
a) partial or complete esters of saturated linear monohydroxylated aliphatic monocarboxylic acids;
b) partial or complete esters of unsaturated monohydroxylated aliphatic monocarboxylic acids;
c) partial or complete esters of saturated monohydroxylated aliphatic polycarboxylic acids;
d) partial or complete esters of saturated polyhydroxylated aliphatic polycarboxylic acids;
e) partial or complete esters of aliphatic C₂ to C₁₆ polyols which have reacted with a mono- or polyhydroxylated aliphatic mono- or polycarboxylic acid,
and their mixtures.
- esters of dimer diol and dimer diacid, if appropriate esterified on their free alcohol or acid functional group(s) by acid or alcohol radicals, in particular dimer dilinoleate esters; such esters can be chosen in particular from esters with the following INCI nomenclature: bis-behenyl/isostearyl/phytosteryl dimer dilinoleyl, dimer dilinoleate (Plandool G), phytosteryl/isostearyl/cetyl/
stearyl/behenyl dimer dilinoleate (Plandool H or Planool S), and their mixtures.
-
- hydrogenated Castor oil esters such as RISOCAST DA-L from Kokyu alcohol kogyo
- and their mixtures.

Advantageously, the pasty compound(s) preferably represents from 0.1 to 80% by weight, better still from 0.5 to 60% by weight, better still from 1 to 30% by weight and even better still from 1 to 20% by weight, with respect to the total weight of the composition.

Wax(es)
According to a preferred embodiment, the composition according to the invention comprises at least one wax.
The wax under consideration in the context of the present invention is generally a lipophilic compound which is solid at ambient temperature (25 degrees centigrade), which exhibits a reversible solid/liquid change in state and which has a melting point of greater than or equal to 30 degrees centigrade which can range up to 200 degrees centigrade and in particular up to 120 degrees centigrade.

In particular, the waxes suitable for the invention can exhibit a melting point of greater than or equal to 45 degrees centigrade and in particular of greater than or equal to 55 degrees centigrade.
The waxes capable of being used in the compositions according to the invention are chosen from waxes which are solid at ambient temperature and which are of animal, vegetable, mineral or synthetic origin, and their mixtures.

Mention may in particular be made, by way of illustration of waxes which are suitable for the invention, of hydrocarbon waxes, such as beeswax, lanolin wax, Chinese insect waxes, rice bran wax, carnauba wax, candelilla wax, ouricury wax, esparto wax, berry wax, shellac wax, Japan wax, sumac wax, montan wax, orange and lemon waxes, microcrystalline waxes, paraffin waxes, ozokerite, polyethylene waxes, the waxes obtained by the Fischer-Tropsch synthesis and waxy copolymers, and also their esters.

Mention may also be made of waxes obtained by catalytic hydrogenation of animal or vegetable oils having linear or branched C₈-C₃₂ fatty chains. Mention may in particular be made, among these, of isomerized jojoba oil, such as the trans isomerized partially hydrogenated jojoba oil manufactured or sold by Desert Whale under the commercial reference Iso Jojoba 50(R), hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil, hydrogenated lanolin oil and di(1,1,1-trimethylolpropane) tetrastearate, sold under the name of Hest 2T-4S(R) by Heterene.

Mention may also be made of silicone waxes (C_30-45 alkyl dimethicone) or fluorinated waxes.
Use may also be made of the waxes obtained by hydrogenation of castor oil esterified with cetyl alcohol which are sold under the names of Phytowax Castor 16L64(R) and 22L73(R) by Sophim. Such waxes are described in Application FR-A-2 792 190.

Use may be made, as wax, of a C₂₀-C₄₀ alkyl(hydroxystearyloxy)stearate (the alkyl group comprising from 20 to 40 carbon atoms), alone or as a mixture.
Such a wax is sold in particular under the names "Kester Wax K 82 P(R)", "Hydroxypolyester K 82 P(R)" and "Kester Wax K 80 P(R)" by Koster Keunen.

Mention may in particular be made, as microwaxes which can be used in the compositions according to the invention, of carnauba microwaxes, such as that sold under the name of MicroCare 350(R) by Micro Powders, synthetic wax microwaxes, such as that sold under the name of MicroEase 114S(R) by Micro Powders, microwaxes composed of a mixture of carnauba wax and of polyethylene wax, such as those sold under the names of MicroCare 300(R) and 310(R) by Micro Powders, microwaxes composed of a mixture of carnauba wax and of synthetic wax, such as that sold under the name MicroCare 325(R) by Micro Powders, polyethylene microwaxes, such as those sold under the names of Micropoly 200(R), 220(R), 220L(R) and 250S(R) by Micro Powders, and polytetrafluoroethylene microwaxes, such as those sold under the names of Microslip 519(R) and 519 L(R) by Micro Powders.

The composition according to the invention can comprise a content of waxes ranging from 0.1 to 30% by weight, with respect to the total weight of the composition; in particular, it can comprise from 0.5 to 20% by weight thereof, more particularly from 1 to 15% by weight thereof.

Physiologically acceptable medium
The term "physiologically acceptable medium" is understood to mean a medium compatible with keratinous substances, such as the oils or organic solvents commonly employed in cosmetic compositions.

The physiologically acceptable medium of the composition according to the invention can also comprise one or more physiologically acceptable organic solvents (acceptable tolerance, acceptable toxicology and acceptable feel).

Additional film-forming polymer
The composition can comprise, apart from the copolymer described above, an additional polymer, such as a film-forming polymer.
According to the present invention, the term "film-forming polymer" is understood to mean a polymer capable of forming, by itself alone or in the presence of an additional agent which is able to form a film, a continuous deposited layer on a support, in particular on keratinous substances.

Mention may be made, among film-forming polymers which can be used in the composition of the present invention, of synthetic polymers of radical type or of polycondensate type, polymers of natural origin and their mixtures. Mention may in particular be made, as film-forming polymer, of acrylic polymers, polyurethanes, polyesters, polyamides, polyureas or cellulose polymers, such as nitrocellulose.

The polymer can be combined with one or more additional agents which are able to form a film. Such an agent which is able to form a film can be chosen from any compound known to a person skilled in the art as being capable of performing the desired role and can in particular be chosen from plasticizing agents and coalescence agents.

Gelling agent
The composition according to the invention can additionally comprise a lipophilic gelling agent.
Organic or inorganic and polymeric or molecular lipophilic gelling agents may in particular be concerned.
Mention may be made, as lipophilic gelling agents, of optionally modified clays, such as modified hectorites, hydrophobic treated silica and their mixtures.

Colouring material
The composition according to the invention can additionally comprise a colouring material chosen from water-soluble dyes and pulverulent colouring materials, such as pigments, pearlescent agents and glitter, well known to a person skilled in the art. The colouring materials can be present in the composition in a content ranging from 0.01% to 50% by weight, with respect to the weight of the composition, preferably from 0.01% to 30% by weight.

The term pigments should be understood as meaning white or coloured and inorganic or organic particles of any shape which are insoluble in the physiological medium and which are intended to colour the composition.
The term pearlescent agents should be understood as meaning iridescent particles of any shape which are in particular produced by certain molluscs in their shells or else synthesized.

The pigments can be white or coloured and inorganic or organic. Mention may be made, among inorganic pigments, of titanium dioxide, optionally treated at the surface, zirconium or cerium oxides, and also zinc, (black, yellow or red) iron or chromium oxides, manganese violet, ultramarine blue, chromium hydrate, ferric blue and metal powders, such as aluminium powder or copper powder.

Mention may be made, among organic pigments, of carbon black, pigments of D & C type and lakes, based on cochineal carmine, of barium, strontium, calcium or aluminium.
Mention may also be made of effect pigments, such as particles comprising an organic or inorganic and natural or synthetic substrate, for example glass, acrylic resins, polyester, polyurethane, polyethylene terephthalate, ceramics or aluminas, the said substrate being or not being covered with metal substances, such as aluminium, gold, silver, platinum, copper or bronze, or with metal oxides, such as titanium dioxide, iron oxide or chromium oxide, and their mixtures.

The pigment can also comprise goniochromatic pigments. These pigments exhibit a relatively large change in color with the angle of observation. The goniochromatic pigment can be chosen, for example, from pigments comprising a multilayer interference structure and liquid crystal pigments.

In the case of a multilayer structure, the latter can comprise, for example, at least two layers, each layer, independently or not of the other layer(s), being produced, for example, from at least one material chosen from the group consisting of the following materials: MgF₂, CeF₃, ZnS, ZnSe, Si, SiO₂, Ge, Te, Fe₂O₃, Pt, Va, Al₂O₃, MgO, Y₂O₃, S₂O₃, SiO, HfO₂, ZrO₂, CeO₂, Nb₂O₅, Ta₂O₅, TiO₂, Ag, Al, Au, Cu, Rb, Ti, Ta, W, Zn, MoS₂, cryolite, alloys, polymers and their combinations.

The goniochromatic agents comprising multilayer structures are in particular those described in the following documents: US-A-3 438 796, EP-A-227 423, US-A-5 135 812, EP-A-170 439, EP-A-341 002, US-A-4 930 866, US-A-5 641 719, EP-A-472 371, EP-A-395 410, EP-A-753 545, EP-A-768 343, EP-A-571 836, EP-A-708 154, EP-A-579 091, US-A-5 411 586, US-A-5 364 467, WO-A-97/39066, DE-A-4 225 031, WO 9517479 (BASF) and DE-A-196 14 637. They are provided in the form of flakes with a metallic color.

The multilayer structures which can be used in the invention are, for example, the following structures: Al/SiO₂/Al/SiO₂/Al; Cr/MgF₂/Al/MgF₂/Al; MoS₂/SiO₂/Al/SiO₂/MoS₂; Fe₂O₃/SiO₂/Al/SiO₂/Fe₂O₃; Fe₂O₃/SiO₂/Fe₂O₃/SiO₂/Fe₂O₃; MoS₂/SiO₂/micaoxide/SiO₂/MoS₂; Fe₂O₃/SiO₂/micaoxide/SiO₂/Fe₂O₃. Different colors are obtained depending on the thicknesses of the different layers. Thus, with the structure Fe₂O₃/SiO₂/Al/SiO₂/Fe₂O₃, the color changes from golden-green to grey-red for SiO₂ layers with a thickness of 320 to 350 nm; from red to golden for SiO₂ layers with a thickness of 380 to 400 nm; from purple to green for SiO₂ layers with a thickness of 410 to 420 nm; and from copper to red for SiO₂ layers with a thickness of 430 to 440 nm.

Consequently, the multilayer structure can be essentially inorganic or organic. Different colors are obtained depending on the thickness of each of the different layers. The goniochromatic pigments comprising a multilayer interference structure according to the invention are in particular those described in the following documents: US-A-3 438 796, EP-A-227 423, US-A-5 135 812, EP-A-170 439, EP-A-341 002, US-A-4 930 866, US-A-5 641 719, EP-A-472 371, EP-A-395 410, EP-A-753 545, EP-A-768 343, EP-A-571 836, EP-A-708 154, EP-A-579 091, US-A-5 411 586, US-A-5 364 467, WO-A-97/39066, DE-A-4 225 031, WO 9517479 (BASF) and DE-A-196 14 637, and their combinations. They are provided in the form of flakes with a metallic color.

The goniochromatic pigment comprising a multilayer interference structure can be chosen from the group consisting of the following commercial goniochromatic pigments: Infinite Colors from Shiseido, Sicopearl Fantastico from BASF, Colorstream, Xirallic and Xirona from Merck, Colorglitter from Flex, and their mixtures.

Liquid crystal pigments are described in particular in Application EP-A-1 046 692. Use may in particular be made, as liquid crystal particles, of those known under the CTFA name Polyacrylate 4 and sold under the names "Helicone(R) HC Sapphire", "Helicone(R) HC Scarabeus", "Helicone(R) HC Jade", "Helicone(R) HC Maple", "Helicone(R) HC XL Sapphire", "Helicone(R) HC XL Scarabeus", "Helicone(R) HC XL Jade" and "Helicone(R) HC XL Maple" by Wacker.

The pearlescent pigments can be chosen from white pearlescent pigments, such as mica covered with titanium oxide or with bismuth oxychloride, coloured pearlescent pigments, such as titanium oxide-coated mica covered with iron oxides, titanium oxide-coated mica covered with in particular ferric blue or chromium oxide or titanium oxide-coated mica covered with an organic pigment of the abovementioned type, and pearlescent pigments based on bismuth oxychloride. Use may also be made of interference pigments, in particular liquid crystal or multilayer pigments.
The water-soluble dyes are, for example, beetroot juice or methylene blue.

Fillers
The composition according to the invention can additionally comprise one or more fillers, in particular in a content ranging from 0.01% to 50% by weight, with respect to the total weight of the composition, preferably ranging from 0.01% to 30% by weight. The term fillers should be understood as meaning colourless or white and inorganic or synthetic particles of any shape which are insoluble in the medium of the composition, whatever the temperature at which the composition is manufactured. These fillers are used in particular to modify the rheology or the texture of the composition.

The fillers can be inorganic or organic and of any shape, platelet, spherical or oblong, whatever the crystallographic form (for example sheet, cubic, hexagonal, orthorhombic and the like). Mention may be made of talc, mica, silica, kaolin, powders formed of polyamide (Nylon(R)) (Orgasol(R) from Atochem), of poly-B-alanine and of polyethylene, powders formed of tetrafluoroethylene polymers (Teflon(R)), lauroyllysine, starch, boron nitride, hollow polymer microspheres, such as those of poly(vinylidene chloride)/acrylonitrile, for example Expancel(R) (Nobel Industrie), or of acrylic acid copolymers (Polytrap(R) from Dow Corning), precipitated calcium carbonate, magnesium carbonate, basic magnesium carbonate, hydroxyapatite, hollow silica microspheres (Silica Beads(R) from Maprecos), glass or ceramic microcapsules, or metal soaps derived from organic carboxylic acids having from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate, lithium stearate, zinc laurate or magnesium myristate.

Other fillers are shown by Table 1 below.

Table 1

NT: no treatment
LL-5%= treated with 5% Lauroyl lysine

The composition according to the invention can be provided in particular in the form of a suspension, dispersion, solution, gel, emulsion, in particular oil-in-water (O/W) or water-in-oil (W/O) or multiple (W/O/W or polyol/O/W or O/W/O) emulsion, cream, foam, dispersion of vesicles, in particular of ionic or nonionic lipids, two-phase or multiphase lotion, spray, powder or paste, in particular soft paste.

Preferably, the composition according to the invention comprises less than 3% by weight or better still less than 1% by weight of water, with respect to the total weight of the composition. More preferably, the composition is completely anhydrous. The term anhydrous is understood to mean in particular that the water is preferably not deliberately added to the composition but may be present in the form of traces in the various compounds used in the composition.

A person skilled in the art will be able to choose the appropriate formulation form and its method of preparation on the basis of his general knowledge, taking into account, on the one hand, the nature of the constituents used, in particular their solubility in the support, and, on the other hand, the application envisaged for the composition.

The composition according to the invention may be intended for caring for and/or making up keratinous substances, in particular the lips and skin, especially the lips.
The composition according to the invention can be in the form of a liquid gloss.
The composition according to the invention can be in the solid form, as a stick or cast in a dish, for example.

The examples which follow illustrate the invention without implied limitation.
The amounts are expressed as percentage by weight.

Fig. 1 is a diagram schematically showing the shape of a fusiform particle

Embodiments of the present invention will be described herebelow. It should be noted that the embodiments and descriptions thereof are provided solely to assist in understanding the present invention and should not be construed as limiting the present invention in any way to the embodiments described below.

Fig.1 schematically shows the shape of a fusiform particle. The particle has a rugby ball shape, that is, a major axis along which the diameter is larger than any other diameters, and two minor axes which are perpendicular to the major axis and which are perpendicular to each other. In fact the two minor axes may be defined in any direction as long as the axes are in the plane perpendicular to the major axes. The diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometer, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometer, and L₁/L₂ between approximately 1.1 and approximately 3.3. As may be understood from Fig. 1, there is a groove on the surface along the major axis, in the particles used in the experiments described below. However, the groove is not necessary.

Table 2 below shows morphology of the particles according to the present invention (Example) which have a fusiform shape, and the comparative particles which have a bowl shape (Reference particle 1 or NLK506), spherical shapes (Reference particle 2 or Tospearl 145A, and Reference particle 3 or Tospearl AQ) or Reference 4 Silica Beads SB700. Their morphology and absorption oil and water are also shown in Table 2.

Table 2

NT: no treatment

Examples
Example 1: Preparation of a poly(isobornyl acrylate/isobornyl methacrylate/isobutyl acrylate/acrylic acid) copolymer
300 g of isododecane are introduced into a 1 litre reactor and then the temperature is increased so as to change from ambient temperature (25 degrees centigrade) to 90 degrees centigrade in 1 hour.
105 g of isobornyl methacrylate, 105 g of isobornyl acrylate and 1.8 g of 2,5-bis(2-ethyl-hexanoylperoxy)-2,5-dimethylhexane (Trigonox(R) 141 from Akzo Nobel) are subsequently added at 90 degrees centigrade in 1 hour.

The mixture is maintained at 90 degrees centigrade for 1h 30.
75 g of isobutyl acrylate, 15 g of acrylic acid and 1.2 g of 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane are subsequently introduced into the preceding mixture, still at 90 degrees centigrade and in 30 minutes.

The mixture is maintained at 90 degrees centigrade for 3 hours and then the combined product is cooled.
A solution is thus obtained comprising 50% of copolymer dry matter in 50% of isododecane, the copolymer comprising a first poly(isobornyl acrylate/isobornyl methacrylate) block or sequence having a Tg of 128 degrees centigrade, a second poly(isobutyl acrylate/acrylic acid) block having a Tg of -9 degrees centigrade and an intermediate block which is an isobornyl acrylate/isobornyl methacrylate/isobutyl acrylate/
acrylic acid random copolymer.
The Tg of the copolymer is 74 degrees centigrade.
These are theoretical Tg values calculated by the Fox law.

Example 2 according to the invention: Distillation of the synthesis solvent (the isododecane) with addition of octyldodecyl neopentanoate
The solution obtained in Example 1 is heated at 130 degrees centigrade under a vacuum of 100 mbar in order to evaporate the isododecane, while simultaneously adding octyldodecyl neopentanoate. The whole of the isododecane is replaced by as much octyldodecyl neopentanoate by weight.

The use of octyldodecyl neopentanoate makes it possible to evaporate all of the isododecane, the latter possibly remaining only in the form of residual traces. A solution comprising 50% of copolymer dry matter in 50% of octyldodecyl neopentanoate is thus obtained.

[Rectified under Rule 91 22.01.2010]
Table 3 below shows the compositions containing rugby ball powder according to the present invention and a comparative example without rugby ball powder.
As shown in Table 3, Embodiments 1 and 2 contain 1 wt% of Rugby ball powder and different only in that Embodiment 1 contains 21.57 wt% of isohexadecane as a solvent while Embodiment 2 contains 21.57 wt% of isododecane. Comparison 1 differs from Embodiment 1 in that the former does not contain Rugby ball powder. Other differences are insubstantial.

Table 3

The procedure for the above formulation is as follows:
= The pigments are milled 3 times on a triple roll mill in octyldodecanol brought beforehand to 60 degrees centigrade. The millbase is left to cool to ambient temperature (25 degrees centigrade) in a jacketed heating vessel or a beaker.
= The copolymer, the squalane, the polybutylene, the pearlescent agents and the fragrance are added to the millbase. Everything is stirred using a turbine (type: Rayneri) in order to homogenize.
= When the mixture is homogeneous, the polyphenyltrimethylsiloxydimethylsiloxane is added with stirring at 800 revolutions/minute using the Rayneri for approximately 30 minutes.
= Finally, the pyrogenic silica is gradually added and stirring using the turbine is maintained at 1000 revolutions/minute for 20 minutes.
This gloss composition, applied to the lips in a single movement, exhibits satisfactory properties of comfort and of gloss.
In addition, the composition exhibits good hold of the colour and of the gloss.
It does not have to be packaged in leaktight packaging.

[Rectified under Rule 91 22.01.2010]
The lipsticks having the composition described in Table 3 were tested with regard to their properties such as hardness, shine in-vitro, application amount and their overall properties were evaluated based thereon. The results are shown in Table 4 below. As may be understood from Table 4, addition of rugby ball powder further improves shine and soft texture of the lipstick.

Table 4

Table 5 shows the results of test performed on the lipstick compositions with and without rugby ball powder as well as other lipstick compositions containing spherical or powders having the shape instead of rugby ball powders. As shown by Table 5, a lipstick containing rugby ball powder is characterized by melty, cushony and soft feel especially when applying on lips while other comparative examples with and without powder cannot depict all of the desired characters described above.

Table 5

Claims (24)

1. Cosmetic composition for making up and/or caring for keratinous substances comprising, in a physiologically acceptable medium, at least:
a) one ethylenic block copolymer (also referred to as ethylenic block polymer) comprising at least one first block having a glass transition temperature (Tg) of greater than or equal to 40 degrees centigrade and resulting, in all or in part, from one or more first monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of greater than or equal to 40 degrees centigrade and at least one second block having a glass transition temperature of less than or equal to 20 degrees centigrade and resulting, in all or in part, from one or more second monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature of less than or equal to 20 degrees centigrade, the said first block and the said second block being connected to one another via a random intermediate segment comprising at least one of the said first constituent monomers of the first block and at least one of the said second constituent monomers of the second block and the said block copolymer having a polydispersity index I of greater than 2,
b) at least one nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol; and
c) fusiform particles being made of an organosilicone having a crosslinked polysiloxane structure, and having diameters along major axis L₁ between approximately 0.05 micrometer and approximately 20 micrometer, diameters along minor axes L₂ between approximately 0.03 micrometer and approximately 15 micrometer, and L₁/L₂ between approximately 1.1 and approximately 3.3;
the said composition comprising less than 10% by weight of volatile oil having a flash point of less than or equal to 80 degrees centigrade, with respect to the total weight of the composition.

The cosmetic composition according to claim 1, wherein the fusiform particles are between approximately 0.5 wt% and 50 wt%, preferably between approximately 0.5 wt% and approximately 10 wt%, more preferably between approximately 0.5 wt% and approximately 3 wt% of the composition.

The cosmetic composition according to claim 1 or 2, wherein the crosslinked polysiloxane comprises first, second and third siloxane units which are SiO₂, R¹SiO_1.5 and R²R³SiO, respectively, wherein R¹, R² and R³ are any one of organic groups, same or different, having a carbon atom directly linked to a silicon atom.

The cosmetic composition according to one of claims 1 to 3, wherein molar ratio of the molar sum of the first siloxane unit and the second unit over the third siloxane unit is between 99:1 to 50:50, preferably between 90:10 to 60:40, approximately.

The cosmetic composition according to one of claims 1 to 4, wherein molar ratio of the first siloxane unit with respect to the second siloxane unit is between 23:77 and 40:60, approximately.

The cosmetic composition according to any one of claims 3 to 5, wherein R¹ and at least one of R² and R³ are selected from the group consisting of epoxy group, (meta) acryloxy group, mercaptoalkyl group, aminoalkyl group and organic groups having any one of preceding groups.

The cosmetic composition according to one of claim 1 to 6, wherein the fusiform particles have slits along their major axes.

The cosmetic composition according to the preceding claim, characterized in that it comprises less than 5% by weight of volatile oil having a flash point of less than or equal to 80 degrees centigrade.

The cosmetic composition according to either one of the preceding claims, characterized in that it does not comprise volatile oil having a flash point of less than or equal to 80 degrees centigrade.

The cosmetic composition according to any one of the preceding claims, characterized in that
the said first monomer or monomers, which are such that the homopolymer prepared from these monomers has a glass transition temperature of greater than or equal to 40 degrees centigrade, are chosen from:
- methacrylates of formula CH₂=C(CH₃)-COOR₁
in which R₁ represents a linear or branched unsubstituted alkyl group comprising from 1 to 4 carbon atoms or a C₄ to C₁₂ cycloalkyl group,
- acrylates of formula CH₂=CH-COOR₂
in which R₂ represents a C₄ to C₁₂ cycloalkyl group,
- (meth)acrylamides of formula:

where R₇ and R₈, which are identical or different, each represent a hydrogen atom or a linear or branched C₁ to C₁₂ alkyl group, or R₇ represents H and R₈ represents a 1,1-dimenthyl-3-oxobutyl group,
and R' denotes H or methyl, and in that
the said second monomer or monomers, which are such that the homopolymer prepared from these monomers has a glass transition temperature of less than or equal to 20 degrees centigrade, are chosen from;
- acrylates of formula CH₂=CHCOOR₃,
R₃ representing an unsubstituted linear or branched C₁ to C₁₂ alkyl group, with the exception of the tert-butyl group, in which is(are) optionally inserted one or more heteroatoms chosen from O, N and S,
- methacrylates of formula CH₂=C(CH₃)-COOR₄,
R₄ representing an unsubstituted linear or branched C₆ to C₁₂ alkyl group in which is(are) optionally inserted one or more heteroatoms chosen from O, N and S;
- vinyl esters of formula R₅-CO-O-CH=CH₂,
where R₅ represents a linear or branched C₄ to C₁₂ alkyl group;
- C₄ to C₁₂ alkyl vinyl ethers,
- N-(C₄ to C₁₂ alkyl)acrylamides, such as N-octylacrylamide,
- and their mixtures.

The cosmetic composition according to any one of the preceding claims, characterized in that the said block copolymer is such that the said first block is obtained from at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₄ to C₁₂ cycloalkyl group and from at least one methacrylate monomer of formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₄ to C₁₂ cycloalkyl group and the said second block is obtained from at least one second monomer having a glass transition temperature of less than or equal to 20 degrees centigrade and from an additional monomer.

The cosmetic composition according to the preceding claim, characterized in that the said additional monomer is acrylic acid.

The cosmetic composition composition for making up and/or caring for keratinous substances comprising, in a physiologically acceptable medium, at least one copolymer comprising at least one acrylate monomer of formula CH₂=CH-COOR₂ in which R₂ represents a C₈ to C₁₂ cycloalkyl group and/or at least one methacrylate monomer of the formula CH₂=C(CH₃)-COOR'₂ in which R'₂ represents a C₈ to C₁₂ cycloalkyl group, at least one second acrylate monomer of formula CH₂=CHCOOR₃ in which R₃ represents an unsubstituted linear or branched C₁ to C₁₂ alkyl group, with the exception of the tert-butyl group, and at least one acrylic acid monomer, the said composition additionally comprising at least one nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol and the said composition comprising less than 10% by weight of volatile oil having a flash point of less than or equal to 80 degrees centigrade, with respect to the total weight of the composition.

The cosmetic composition according to any one of Claims 11 to 13, characterized in that R₂ and R'₂ represent, independently or simultaneously, an isobornyl group.

The cosmetic composition according to any one of the preceding claims, characterized in that the said copolymer is obtained from at least one isobornyl methacrylate monomer, at least one isobornyl acrylate monomer, at least one isobutyl acrylate monomer and at least one acrylic acid monomer.

The cosmetic composition according to any one of the preceding claims, characterized in that the said copolymer comprises from 50 to 80% by weight of isobornyl methacrylate/acrylate, from 10 to 30% by weight of isobutyl acrylate and from 2 to 10% by weight of acrylic acid.

The cosmetic composition according to any one of the preceding claims, characterized in that it comprises from 0.5 to 40% by weight of block copolymer active material and advantageously from 1 to 40% by weight, in particular from 2 to 30% by weight, indeed even from 2 to 20% by weight, of copolymer active material, with respect to the total weight of the composition.

The cosmetic composition according to any one of the preceding claims, characterized in that the said nonvolatile hydrocarbon oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol is octyldodecyl neopentanoate.

The cosmetic composition composition according to any one of the preceding claims, characterized in that the ratio by weight of the said block copolymer to the nonvolatile hydrocarbon ester oil comprising at least 16 carbon atoms and having a molar mass of less than 650 g/mol is less than 1.

The cosmetic composition composition according to any one of the preceding claims, characterized in that it comprises less than 3% of water or better still less than 1% or even is entirely anhydrous.

The cosmetic composition composition according to any one of the preceding claims, characterized in that it additionally comprises at least one volatile oil having a flash point of greater than 80 degrees centigrade.

The cosmetic composition composition according to any one of the preceding claims, characterized in that it comprises at least one wax and/or one pasty fatty substance and/or one additional nonvolatile oil and/or one filler and/or one colouring material.

The cosmetic composition composition according to any one of the preceding claims, characterized in that it is in the solid form.

Cosmetic method for making up keratinous substances comprising the application, to the said keratinous substances and in particular the lips or the skin, of a composition as defined in any one of the preceding claims.

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