AGENTS FILMOGENES POLYESTERS BIOSOURCES

Abstract

BIO-BASED POLYESTER FILM-FORMING AGENTS The invention relates to novel biodegradable film-forming agents of bio-based origin, obtained by esterification reaction between polyols and polyacids, said acids and alcohols being chosen to form solid crystalline or semi-crystalline polyesters capable of forming a thin film, usable in the cosmetic field. In particular, the invention aims to provide polyesters from bio-based compounds. Said bio-based polyesters are not only capable of forming a thin film on the skin, but also ensure the adhesion of the formulation and give it water and oil resistance, long-lasting properties, as well as anti-transfer properties.

Description

Title of the invention: FILM-FORMING AGENTS POLYESTERS FROM BIOSOURCES

[0001] The invention relates to new film-forming agents of bio-based origin, obtained by esterification reaction between polyols and polyacids, said acids and alcohols being chosen so as to form solid polyesters - crystalline or semi-crystalline - capable of forming a film.

[0002] In particular, the invention aims to provide polyesters, derived from bio-based compounds, suitable for use in cosmetics, especially in skin protection and makeup. These bio-based polyesters are not only capable of forming a thin film on the skin, but also of ensuring the adhesion of the formulation to the skin, and thus provide it with water and oil resistance, long-lasting wear, and anti-transfer properties.

[0003] The invention also relates to the development of said film-forming polyester polymers by an eco-designed esterification process, from polyfunctional bio-based compounds, alcohols and acids, without the use of catalysts or solvents, and to their use in cosmetic formulations. STATE OF THE ART

[0004] The effectiveness of a cosmetic product is linked to the quality of its ingredients, but also to its ability to spread easily on the skin and, above all, to remain there, at least for the duration of the treatment. To prepare a cosmetic product with the desired properties, it is common to use a film-forming polymer.

[0005] The object of the present invention is to develop new polyesters enabling the formation of film on keratinous materials, in particular human, such as skin - body and face - lips, eyelashes, eyebrows and hair, when implemented in a cosmetic product.

[0006] By "film-forming agent" is meant an ingredient capable, when used in a mixture in cosmetic formulations, of forming a thin, micrometric film on the application surface and giving the deposited formulation resistance to external stresses. Thus, a film-forming agent is said to be "anti-transfer" when it allows the components of the formulation—pigments, sunscreens, colorants, or active ingredients—to be retained on the treated surface without leaving any trace or ingredient on the surface with which it comes into contact. Products formulated in this way, for example, foundations or lipsticks, eyeshadows or blushes, mascaras, or pencils, are distinguished by the fact that once applied to the On skin or lips, they do not leave a noticeable deposit on the surfaces they come into contact with (glass, cup, cigarette, clothing, for example). This will also allow the formulations to last over time and, even for sunscreen formulations, to be resistant to water, oils, or sand.

[0007] In particular, makeup products are cosmetic formulations that require excellent adhesion of the product to the skin and the formation of a film to optimize their effectiveness. The film-forming deposits must have good adhesion, in particular good resistance to friction from the skin or clothing to prevent transfer, good resistance to contact with water, and resistance to fatty substances such as oils contained in food.

[0008] A second field of application in cosmetics of film-forming polymers is that of sun protection products, in particular emulsions, milks, creams, gels, oils and "anti-UV" sticks which require excellent adhesion to the skin and the formation of a film to guarantee an optimal level of protection against UV rays over the duration of use of the product but also to ensure good hold or resistance to water, when swimming or when in contact with perspiration.

[0009] Film-forming polymers must also, in addition to the target properties of skin adhesion, water resistance and anti-transfer, possess acceptable mechanical properties for use in cosmetic products, in particular the formation of a non-sticky, comfortable, flexible, lightweight film, in particular to accompany the movements of the skin, without causing a feeling of tightness or discomfort.

[0010] Today, the desired properties are mostly achieved with petroleum-derived compounds. Thus, petroleum-based film-forming agents still occupy a predominant place in cosmetic formulations, and synthetic polymers such as silicone resins, PVP / olefin (polyvinylpyrolidone-olefin) copolymers, or acrylate copolymers are widely used to give cosmetic formulations unique sensory properties, long-lasting wear, or water resistance.

[0011] For example, water-resistant film-forming agents for sunscreens or sunscreens have been known for a long time, such as PVP / olefin copolymers or acrylate copolymers. These synthetic polymers have been developed to impart water resistance to sunscreen products with sun protection factors (SPF) and water resistance sun protection factors (SPFiwr) ranging from 15 to 50 and above. These polymeric materials can be characterized by high molar masses (approximately 50,000 g / mol to over 1,000,000 g / mol) and are present in the formula at a concentration of 2% by mass. Among them, Ganex™ polymers [by For example, Antaron™ V-220F Polymer (INCI: VP / Eicosene Copolymer), Antaron WP-660 (INCI = Triacontanyl PVP)] (WO 2021 0259930, Nouryon) are still very commonly used and are capable of giving formulations high sun protection (SPF 50 or more) and also significant water and wash-off resistance (SPF 50 or more).

[0012] But these synthetic polymer ingredients are derived from fossil resources, often limited and extracted by processes that can have irreversible adverse impacts on the environment.

[0013] Many polyesters available on the market are made from non-renewable resources, which maintains a certain impact on the environment despite their biodegradability. The use of plant-based monomers would contribute to reducing CO2 emissions into the atmosphere.

[0014] Application CN114075423 describes low surface energy polyesters obtained from dicarboxylic acids and dialcohols for hot melt adhesive applications. The dicarboxylic acid precursors include terephthalic acid, isophthalic acid, and sebacic acid, while the dialcohols include glyceryl monostearate, butanediol, diethylene glycol, and ethylene glycol. Despite the low polarity of these systems, which allows for adhesion and water resistance, ether-based polyesters are not bio-based; moreover, the ether component limits their biodegradability, thus removing their appeal for current and future cosmetic applications.

[0015] US patent 6,242,499 also describes polyesters containing polyether derivatives. These polyesters are obtained by esterification of a mixture of polyglycerols (ether) with saturated or unsaturated, linear or branched fatty acids having 12 to 22 carbon atoms and polyfunctional carboxylic acids having 4 to 54 carbon atoms and an average functionality of 2 to 2.4, the degree of esterification of the polyglycerol mixture being between 30 and 75%. The resulting polyesters are described as colored viscous products useful as oil-in-water emulsifiers in cosmetic or pharmaceutical preparations and as auxiliaries for dispersing inorganic micropigments in oil dispersions. But their liquid state does not guarantee a film-forming property and no instruction is given on their water resistance or anti-transfer properties.

[0016] Also based on polyglycerols, widely used until then, US patent 8,465,730 describes solar formulations characterized by a synergistic effect between a cross-linked waterproofing polyester—prepared by reacting a mixture of polyglycerol, a diacid, and a mixture of at least two different fatty acids—and solar actives. The material's UV protection performance depends on the adjustment of the ratio of fat groups, as well as the crosslinking agent.

[0017] Similarly, US patent applications US20210259946, US20210259930, and US20210259945 disclose biodegradable, waterproof, film-forming polyesters for various sun care formulations. These polyesters are the product of a reaction between a polyglycerol, a chain-extending dimer or trimer acid (hydrogenated C8-30 fatty acid dimers), and a mono-fatty acid, such as isostearic acid. The fatty acid content allows for adjusting the hydrophilic / hydrophobic character of the polyester. This preference for isostearic acid over stearic acid results in a low viscosity at room temperature for isostearic acid, which can lead to a liquid material.

[0018] Similarly, application WO2018 / 033259 describes partial polyglycerol esters that can be obtained by esterifying a polyglycerol with carboxylic acids such as polyhydroxystearic acid and polyricinoleic acid, sebacic acid, dimerized oleic acid and / or linoleic acid and oleic acid and isostearic acid, having improved emulsion stabilization capacity at high oil content, particularly for cosmetic or pharmaceutical preparations. This material is based on a cross-linked polyether. No information is provided regarding the naturalness of the product or its biodegradability.

[0019] The use of fully bio-based polyesters in cosmetic formulations is rarely described. Application EP3786302 discloses a process for the catalytic transesterification of (hydrogenated) jojoba wax esters with a lipase, while application EP3344777 discloses the transesterification of jojoba wax esters with an alcohol such as oleyl alcohol, for cosmetic and personal care products. However, such a transesterification process does not lead to polymer chains, and the transesterified product is a liquid that therefore lacks cohesion to perform satisfactorily in applications requiring film-forming and transfer-resistant properties.

[0020] US patent 7317068 describes a polyester polyol intended for use in personal care products comprising the reaction product of polyfunctional alcohols with polyfunctional carboxylic acids and monofunctional carboxylic acids. Such polyesters are in liquid form and are claimed as replacements for viscous oils in the cosmetics industry, such as castor oil, in terms of viscosity and polarity. Although such polymers may be useful as water-resistant ingredients, they are unsuitable for many other applications, particularly in the beauty industry, where anti-transfer properties are mandatory.

[0021] The processes for obtaining these polymers are themselves often very polluting, and harmful catalysts or solvents may be used, as well as by-products. toxic substances released into the air, water and soil. The environmental impacts of petroleum-based polymers are all the more significant because, at the end of their life cycle, they constitute a source of micro- or nanoplastics in nature, as they are rarely biodegradable. In recent years, measures aimed at reducing the environmental impact of plastics have prioritized limiting the entry of micro- and nanoplastics into ecosystems and their persistence in the environment (Actualité Chimique No. 456-457-458, 122 November-December-January 2020-2021). Currently, a thorough examination is underway of micro- and nanoplastics that are released daily during showers and baths, and which do not decompose in the environment.Consequently, manufacturers of high SPF and FPSiwr sunscreens and protective products remain under market and regulatory pressure to provide more natural products, free of microplastics and whose ingredients can be biodegraded at the end of their life cycle.

[0022] From an environmental point of view, the biodegradability of plastics is a key focus in the search for effective solutions for managing the plastic-environment relationship. It is therefore necessary and urgent to find alternatives to petroleum-based, persistent, and non-biodegradable polymers. And it is now essential to use renewable resources and synthesis processes that adhere to the principles of green chemistry for the development of polymer ingredients. Bio-based and biodegradable polymer ingredients exist today, but their performance level remains lower than that of synthetic polymers. Producing cosmetic ingredients that combine natural origins and biodegradability with high-level performance is currently a challenge.

[0023] 11 It is therefore sought to have film-forming polymers which possess the set of these characteristics: bio-based origin, adhesion to skin, mechanical and water resistance, "anti-transfer" property.

[0024] The object of the invention is thus to develop new polyesters enabling the formation of a film on keratinous materials, in particular human such as skin - body and face - lips, eyelashes, eyebrows and hair when used in a cosmetic product and to make available to cosmetic product manufacturers polymers with high-performance film-forming and anti-transfer properties, while having a lower environmental impact than existing references on the market. Description of the invention

[0025] The invention relates to crystalline and / or semi-crystalline polyester compounds, obtained from bio-based derivatives, suitable for use in cosmetic products and which have film-forming properties.

[0026] By "crystalline" polymers, we mean a polymer which has both crystalline regions and a melting temperature, Tf.

[0027] By "semi-crystalline" polymers, we mean a polymer which has both crystalline and amorphous zones (non-crystalline zones, characterized by a glass transition temperature, Tg).

[0028] The term "bio-based" refers to a product partially or entirely prepared from renewable organic matter (biomass) derived from the plant, fungal, microbial, or animal world. Such a product may also be described as "bio-based" or "naturally derived," terms commonly used in the field of polymers. A bio-based polymer is typically defined according to its naturalness index as given by ISO 16128. A fully bio-based polymer has a naturalness index of 1, while a partially bio-based product has a naturalness index strictly less than 1.

[0029] Advantageously, the film-forming polyester according to the invention has the following characteristics: - a bio-based origin, - temperature-adjusted crystallinity, - a targeted molar mass, - a specific surface energy, and - an adjusted lipophilic / hydrophilic balance.

[0030] The film-forming polyester compounds according to the invention correspond to the formula (I) below:

[0031] [Chem.l]

[0032] (I)

[0033] in which, - W, X are chosen from alkyl radicals derived from polyacids and polyols, comprising from 2 to 36 carbon atoms; - Y is chosen from alkyl radicals derived from branched aliphatic polyols, comprising 3 to 36 carbon atoms - Z is chosen from polyacids which can be fatty acid-derived dimers, comprising from 2 to 36 carbon atoms;

[0034] - V is selected from fatty-chain, branched polyols, such as dimers fatty acids or oligopolyesters, comprising 3 to 90 carbons. DESCRIPTION OF FIGURES

[0035] Fig. 1 represents the comparison of the quantity of UV filters of a sunscreen formulation released as a function of the nature of the film-forming polymer (Test 3 of Example 21). DETAILED DESCRIPTION OF THE INVENTION

[0036] The object of the invention is the development of crystalline and / or semi-crystalline polyester compounds, obtained from bio-based derivatives, suitable for use in cosmetic products and which have film-forming properties. In addition, the structure of these polymers is specially designed to ensure their bio-based origin, their adhesion to the skin and their film-forming properties. Advantageously, the polyester compounds according to the invention, when used in cosmetic formulations, make it possible to limit the transfer of colors from makeup products, particularly in formulations such as lipstick, foundation, mascara, eyeshadow and eyeliner, but also to increase the water resistance of cosmetic products, particularly sun protection formulas, through the use of new polyester polymer ingredients.

[0037] Although polymers of this type are currently commercially available, film-forming polyesters that exhibit all of these properties, namely that are derived from natural resources, and that impart anti-transfer properties and water and oil resistance to cosmetic formulations, are non-existent.

[0038] The structure of these polyesters is specially designed to ensure their bio-based origin, their adhesion to the skin and their film-forming properties as defined by the following characteristics: - monomer units derived from bioresources, whether plant, animal, microbial or fungal; - a chain of repetitive units only of ester type, with unit molar masses less than 600g / mol, this type of chain allows the polyester to be easily biodegradable; - a solid state at body temperature, characterized by a melting point (Tf) greater than or equal to 50°C and less than or equal to 80°C; this melting point facilitates the use in cosmetic formulation, allows good mechanical resistance of the film, long-lasting wear and promotes the "anti-transfer" property; - a surface free energy (Σ) of less than 35 mJ / m2 to ensure good adhesion; this value is lower than those commonly described for skin (38.5 to 46 mJ / m2) and lips (35 mJ / m2) (Surface Science and Adhesion in Cosmetic, Wiley 2021f - an average number molar mass greater than or equal to 3000 g / mol and less than 50000 g / mol, preferably an average number molar mass between 3000 and 40000 g / mol, in particular between 3000 and 30000 g / mol, especially between 3000 and 10000 g / mol, and more particularly between 4000 and 7000 g / mol; these average number molar mass values ​​promote inter-chain interactions and the cohesion of the polymer film, without altering its compatibility with the other ingredients of the formulation, nor the sensory experience of the cosmetic product. Furthermore, these average number molar mass values ​​ensure an acceptable sensory experience of the film for the consumer;

[0039] - a water contact angle (0water) between 80° and 150°, preferably between 80° and 120°, in particular between 80° and 100°, allowing sufficient water resistance and sufficient hydrophobic character of the polymer for use in cosmetics; - an oil contact angle (0huiie) between 15° and 90°, allowing sufficient wetting of keratin materials, sufficient resistance to fats and a sufficiently lipophobic character of the polymer for use in cosmetics.

[0040] The film's adherence to the body surface is linked to the cohesion of the polymer chains, which, according to the invention, is provided by the crystallinity of the polyester. The melting temperature of said polyesters is chosen to be higher than body temperature. Preferably, the melting temperature is above 50°C but below 80°C to facilitate its use in cosmetic formulations.

[0041] The term "sensory perception" refers to organoleptic properties such as sight, touch, taste, and smell. Here, "acceptable sensory perception" refers to a pleasant feel, without hardening of the application surface and without perceptibility of the deposited film.

[0042] It should be noted that, in this description, and unless otherwise stipulated, the ranges of values ​​indicated are understood to include the limits.

[0043] In the present description, the terms "film-forming" and "capable of forming a film" shall be used interchangeably.

[0044] The length of the monomer units is an important parameter. It allows for the optimization of the distance between the polar ester groups and thus the balancing of the polar / dispersive components of the film in order to minimize its surface energy and ensure its adhesion to the skin. Furthermore, the repeating units of the polyester must not exceed 600 g / mol to ensure maximum biodegradability. The length of the monomer units has an impact on the crystallinity and biodegradability of the material.

[0045] To ensure good wettability of the substrate (the skin), as well as good adhesion and diffusion, the film-forming polyester coating the skin preferably has a surface free energy (SLE) lower than the surface free energy of the skin, to guarantee a thermodynamically favorable condition. Depending on the location, type, and presence of residues, the SLE of the skin can vary from 38.5 to 46 mJ / m². For good wettability, adhesion, and diffusion, the film-forming polyester preferably has an SLE of less than 35 mJ / m².

[0046] Water and oil resistance are also desirable properties for cosmetic applications, particularly to ensure the wettability and long-lasting durability of the film-forming polyester. Given the hydrophobic nature of the skin, the film-forming polyester should preferably have a water contact angle (θwater) at 10s greater than or equal to 80° and an oil contact angle (θoil) at 10s between 15° and 90°.

[0047] Advantageously, the polyester compounds according to the invention can be developed from bio-based polyacid and polyol monomers and / or divalent acid / alcohol multifunctional monomers whose associated characteristics are adapted to ensure these properties.

[0048] The invention therefore relates, according to a first aspect, to a bio-based crystalline and / or semi-crystalline polyester compound capable of forming a film, of formula (I):

[0049] [Chem.l]

[0050] (I)

[0051] in which: - W and X, identical or different, independently represent a linear or cyclic aliphatic alkyl radical, comprising from 2 to 36 carbon atoms, preferably from 4 to 28 carbon atoms, said radical possibly comprising one or more unsaturations but not including any ether, amine or thiol function; - Z represents a linear or branched, or cyclic, aliphatic alkyl radical comprising from 2 to 36 carbon atoms, preferably from 4 to 28 carbon atoms, said radical possibly comprising one or more unsaturations but not including any ether, amine or thiol function; - Y represents a branched aliphatic alkyl radical, comprising from 3 to 36 carbon atoms, preferably from 4 to 31 carbon atoms, in particular from 12 to 31 carbon atoms, said radical possibly comprising one or more unsaturations but not including any ether, amine or thiol function; - V represents a branched or cyclic aliphatic alkyl radical, or aromatic, comprising from 3 to 90 carbon atoms, preferably from 6 to 75 atoms, but not including any ether, amine or thiol function; - Ri represents H or an acyl-(C=O)R group, where R is an aliphatic, linear, branched or cyclic alkyl radical comprising from 2 to 90 carbon atoms, said radical possibly having unsaturations and one or more alcohol or acid type functions; - R2 represents an -OH group or an -OR termination where R', identical to or different from R, is an aliphatic, linear, branched or cyclic alkyl radical comprising from 2 to 36 carbon atoms, said radical being able to include unsaturations and one or more alcohol or acid type functions; - n, m and p represent, independently, an integer whose sum (n+m+p) is such that the number molar mass of the polymer is greater than 3000g / mol but less than 50000g / mol; - n is an integer from 1 to 400; - m is an integer from 0 to 160 and chosen such that the ratio (m / n+m+p) is between 0 and 0.4; - p is an integer from 0 to 20 and chosen such that the ratio (p / n+m+p) is between 0 and 0.05, and exhibiting the following characteristics: - it is made up of bio-based monomer units, in particular derived from plant, animal, fungal or microbial bioresources; - its melting point is between 50°C and 80°C; - it has a surface free energy of less than 35 mJ / m2; - it has a number average molar mass greater than or equal to 3000 g / mol and less than 50000 g / mol, preferably a number average molar mass between 3000 and 40000 g / mol, in particular between 3000 and 30000 g / mol, especially between 3000 and 10000 g / mol, more particularly between 4000 and 7000 g / mol; - it has a water contact angle between 80° and 150°, preferably between 80° and 120°; and - it has an oil contact angle between 15° and 90°.

[0052] W and X allow the polymer to have a crystalline or semi-crystalline structure.

[0053] Advantageously, W, X, Y and Z do not include any ether, amine or thiol function in order to maximize biodegradability.

[0054] According to a preferred aspect, W and X, independently, identical or different, are derived from polyacid monomers and polyols containing from 2 to 36 carbon atoms, of preference for 4 to 28 carbon atoms. In particular, X is derived from polyacid monomers. In particular, W is derived from polyol monomers.

[0055] According to another preferred aspect, Z and X may be identical or different. In particular, Z is derived from polyacid monomers, notably fatty acid-derived dimers. Y is chosen so as to adjust the melting temperature of the polyester compound according to the invention above that of the body, to modulate the cosmeticity (rigidity, flexibility) of the film, to make the polyester ingredient compatible with oils of natural origin and to adjust the lipophilic / hydrophilic balance.

[0056] According to a preferred aspect, Y is derived from branched polyol monomers comprising from 3 to 36 carbon atoms, preferably from 4 to 31 carbon atoms, in particular 12 to 31 carbon atoms, especially 21 carbon atoms. Preferably, Y can be present in said polyester compound in an amount between 0 and 40 mol%. Advantageously, this makes it possible to adjust the melting temperature above body temperature, to modulate the cosmetic properties (rigidity, flexibility) of the film, to make the polyester ingredient compatible with natural oils, and to adjust the lipophilic / hydrophilic balance.

[0057] According to another preferred aspect, V can be selected from monomers derived from fatty chain polyols, branched, such as fatty acid dimers or oligopolyesters, comprising 3 to 90 carbons. According to another preferred aspect, V can be derived from aliphatic or aromatic polyol monomers such as catechols.

[0058] According to another preferred aspect of the invention, the skin adhesion and surface energy of the polyester compound of formula [(I) can be adjusted by the addition of fatty acid derivatives and / or fatty chain polyols from Z and V respectively: So, - Z can be chosen from polyacids that may be fatty acid-derived dimers, comprising from 2 to 36 carbon atoms; and / or - V can be selected from monomers derived from branched fatty-chain polyols, such as hydroxylated fatty acid dimers or oligopolyesters, comprising 3 to 90 carbons, preferably 6 to 75 carbon atoms, as indicated above.

[0059] According to a preferred aspect, V may be present in said polyester compound in an amount between 0 and 5 molar %.

[0060] In particular, V can be derived from polyol monomers, which may be dimers derived from hydroxylated fatty acids or divalent multifunctional alcohol oligopolyesters when composed of 36 to 90 carbon atoms, said oligopolyesters being themselves composed of repeating ester units with a molar mass of less than 600g / mol to be perfectly biodegradable. Such oligomers are, for example, represented by the following formulas:

[0061] [Chem.2]

[0062] [Chem.3]

[0063] with n such that the oligopolyester [Chem 2] comprises 37 to 90 carbons, such as for example a PRIC® compound ([Chem 2]) or PRIPOL® ([Chem3]).

[0064] According to another preferred aspect of the invention, aromatic units such as multifunctional compounds derived from catechols are present. Catechol units can be introduced into the polyester compound according to the invention when: - Ri is chosen from catechol derivatives, such as, for example, 3,4-dihydroxyhydrocinnamic acid or gallic acid,

[0065] [Chem. 4] 3,4^ihydraxyhydroœ^

[0066] [Chem. 5] OH

[0067]

[0068]

[0069] Gaic acid and / or - V is chosen from derivatives containing catechol-type units (OH divalent) and additional alcohol functionality such as, for example: [Chem. 6] Acid

[0070] [Chem. 7]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] Querceine [Chem. 8] OH O. XX A ..OH HO"'" Y" 'O""" o OH eHagic acid In particular, V can be derived from polyol monomers containing catechol-like units. According to the invention, the choice of parameters W, X, Y and V allows the ratio between the polar and dispersive components of the structure to be adjusted to ensure a good balance between water resistance and skin adhesion, and allows targeting a suitable melting temperature for cosmetic applications to maximize film cohesion. According to a preferred aspect, W and X are identical linear or cyclic alkyls, comprising 4 to 28 carbon atoms and will represent at least 80 molar percent of the polymer structure. In another preferred aspect, Y comprises a branched chain of 4 to 31 carbon atoms, preferably 18 carbon atoms, and represents up to 40 molar percent of the polymer structure. The desired properties must be retained despite the change in the nature of the ingredients in the formulation. The additional presence of dangling radicals along the polyester chain allows for fine-tuning chain cohesion, enhancing water and oil resistance, improving transfer and durability properties, and enhancing dispersion quality. "Dangling radicals" are groups bonded at a single point of connection to the rest of the polyester chain and not located at the chain ends.

[0077] The polyesters according to the invention are of natural origin, that is to say, produced from ingredients of 100% natural origin (plant, animal, fungal or microbial), whether chemically modified or not. They can therefore be described as "bio-based" or "of bio-based origin", as defined above.

[0078] Bio-based units are generally derived from plant matter such as trees or plants, for example sugar cane, beetroot, sunflower, palm, castor bean and others, or from animal matter such as fats. "Of natural origin" means a product partially or entirely prepared from natural materials (animal, plant, fungal or microbial).

[0079] The acid precursor that can be used in the preparation of the polyester compounds according to the invention may be chosen, for example, from C4-C12 aliphatic diacids, such as sebacic acid, adipic acid, succinic acid, glutaric acid, azelaic acid, or diacids comprising a heterocycle having 3 to 10 members and comprising 1 or 2 ether, amine, or thiol groups, such as furandicarboxylic acid (FDCA) or ricinoleic acid oligoesters. More generally, and without being exhaustive, acid precursors may be chosen from: - 2,5-furandicarboxylic acid (C6H5O4), obtained by bio-fermentation of fructose for example; - Itaconic acid (C5H6O4), obtained from fructose for example; - Succinic acid (C4H6O4), obtained from glucose fermented by E. coli for example; - Glutaric acid (C5H8O4), obtained from sugar for example; - Adipic acid (C6HiO4), obtained from saccharic acid for example; - Heptanedioic acid (C7Hi2O4), obtained from castor oil for example; - Azelaic acid (C9Hi6O4), obtained from oleic acid for example; - Sebacic acid (CiOHi8O4), obtained from castor oil for example; - Undecanedioic acid (CnH2O04), obtained from castor oil for example; - Dodecanedioic acid (Ci2H22O4), obtained from bio-fermentation of lauric acid (coconut) for example; - Brassylic acid (Ci3H24O4) obtained from erucic acid (rapeseed) for example; - Tetradecanedioic acid (Ci4H26O4), obtained by bio-fermentation of myristic acid (coconut) for example; - Hexadecanedioic acid (Ci6H30O4), obtained by bio-fermentation of palmitic acid (palm) for example; - Octadecanedioic acid (C[8H34O4], obtained by bio-fermentation of stearic acid for example; - Eicosanedioic acid (C20H38O4), obtained by bio-fermentation of arachidic acid (rapeseed) for example; - Docosanedioic acid (C20H38O4), obtained by metathesis of undecylenic acid (ricin) for example; - Fatty acid dimers (containing 36 carbon atoms in particular), obtained from unsaturated acids, such as oleic acid; - Diacid oligoesters (polyester containing acidic functions at the ends of chains), obtained from bio-based oil derivatives.

[0080] Alcohol precursors, which can be used in the preparation of polyester compounds according to the invention, can be chosen, for example, from C4-C12 aliphatic dialols such as ethylene glycol, 1-4 butanediol, 1-10 decanediol, or branched alcohols such as 2-3 butanediol or polyester diols such as Pripol® or PRIC®.

[0081] More broadly, and without being exhaustive, naturally sourced and / or bio-based dialcohols can be used, for example, among: - Ethylene glycol (C2H6O2), obtained by hydrogenolysis of xylitol, for example: - 1,2-propanediol (C3H8O2) obtained by hydrogenolysis of xylitol for example; - 1,3-propanediol (C3H8O2) obtained for example from glycerol fermented by Lactobacillus; - 2,3-Butanediol (C4H10O2) obtained from glucose for example; - 1,4-Butanediol (C4H10O2) obtained from glucose fermented by E. coli for example; - 1,4-pentanediol (C5H12O2) obtained by a fermentation process of resources such as corn or sugar cane; - 1,5-pentanediol (C5H12O2) obtained by hydrogenation of levulinic acid; - 1,6-Hexanediol (C6H14O2) obtained by hydrogenation of vegetable oil; - 1,10-decanediol (C10H22O2) obtained by hydrogenation of rapeseed or soybean oil; - 1,12-dodecanediol (C12H26O2) obtained by oxidative cleavage of vernolic acid; - Isosorbide (C6H10O4) obtained by hydrolysis of cellulose; - Glycerol (C3H8O3) obtained by hydrolysis of vegetable oil; - Dialcol oligoesters (polyester containing alcohol functions at the end of chains), obtained from bio-based oil derivatives; - Monoglycerides and diglycerides of fatty acids extracted from vegetable oils.

[0082] Also, bio-based multifunctional acid / alcohol derivatives may be selected from: - Lactic acid (C3H6O3) obtained by a fermentation process; - Glycolic acid (C2H4O3) obtained by hydrolysis of vegetable oil followed by catalytic oxidation; - Citric acid (C6H8O7) obtained by a microbiological fermentation process; - PRICA monoacid ricinoleic acid oligoesters; - all catechulen derivatives.

[0083] The invention also relates to the development of said film-forming polyester polymers by an esterification process, from polyfunctional bio-based compounds, alcohols, and acids. The synthesis process according to the invention is eco-designed, without the use of solvents or catalysts. It makes it possible to obtain a polyester capable of forming a film when used in cosmetic formulations of various kinds.

[0084] The process for preparing film-forming polyester compounds according to the invention comprises the following steps: - formation of an oligomer by condensation between at least one polyacid and at least one polyalcohol; and - complete polymerization between the previously formed oligomers.

[0085] The synthesis is carried out from a stoichiometric mixture between the alcohol and acid functions provided by at least one polyacid and at least one polyalcohol.

[0086] The equivalents are calculated from the acid and alcohol levels provided by the raw material manufacturers in the CoA (Certificate of Analysis) of the product or are determined by dosage.

[0087] The step of forming an oligomer by condensation between at least one polyacid and at least one polyalcohol preferably lasts between 1 and 35 hours, and more preferably between 4 and 30 hours. The reaction is preferably carried out at a temperature between 100°C and 180°C, in particular between 130°C and 160°C. This step is preferably carried out in a sealed system that has been previously dried and placed under vacuum.

[0088] The complete polymerization step between the previously formed oligomers preferably lasts between 1h and 15h, and more preferably between 4h and 10h. The reaction is preferably carried out at a temperature between 150°C and 215°C. particularly between 160°C and 190°C. This step is preferably carried out in a sealed system that has been previously dried and placed under vacuum.

[0089] Advantageously, this process requires no catalyst or additive, and therefore no purification step.

[0090] The invention also relates to the use of a polyester compound as described above in a cosmetic formulation, in particular a direct emulsion (oil / water), a reverse emulsion (water / oil) or an anhydrous formulation.

[0091] The invention also relates to cosmetic compositions containing said film-forming polyester compound.

[0092] In particular, said polyester compound enables the structuring of the oily medium. "Structuring of the medium" refers to the formation of intermolecular interactions even in an oily medium thanks to the crystalline behavior of the polyester.

[0093] In particular, said polyester compound according to the invention can be used in mixture with a chosen oil, for example, from vegetable oils and mixtures of non-polar and more polar oils, in particular of natural origin.

[0094] Said oils may be chosen, for example, from vegetable or natural origin oils, such as caprylic / capric triglyceride, helianthus annuus seed oil, ethylhexyl palmitate, castor oil, coconut oil, glycine soja oil, Polyglyceryl-4 Oleate (and) Glyceryl Olivate (and) Hydrogenated Rapeseed Alcohol, Isopropyl myristate, di-caprylyl carbonate, ethyl oleate, prunus domestica seed oil, prunus amygdalus dulcis oil, sesamum indicum seed oil, simmondsia chinensis seed oil, olea europaea fruit oil, vitis vinifera seed oil, punica granatum seed oil, ricinus communis seed oil, triticum vulgare germ oil, octyldodecanol, coco-caprylate, and corylus avellana seed oil (INCI name).

[0095] The general and specific aspects of the invention described above apply equally to the film-forming polyester compounds described above, to their preparation process and to their use in a composition implementing them, in particular a cosmetic formulation.

[0096] The invention is illustrated, but not limited to, by the examples below. EXAMPLES

[0097] Examples 1 to 5 and 7 to 14 relate to the preparation of film-forming polyester polymers according to the process of the invention. Examples 6 and 15 to 18 are comparative examples relating to polymers which are outside the scope of the invention. Examples 19 relate to cosmetic formulations including film-forming polyester polymers. Example 20 concerns tests of the anti-transfer properties of formulations. including film-forming polyester polymers. Example 21 relates to water resistance tests of formulations including film-forming polyester polymers.

[0098] Table 1 below shows the characteristics of the polymers in examples 1 to 6.

[0099] [Tables 1] C10-C10-C18 Variations (%mol) Example No. Reaction SC10-C18 Tf (°C) Mn (g / mol) Û ^water (°) ^oil C) Es (mJ / m2) 1 DES23007 100% - 0% 77 7000 115 16 30 2 DES23024 97.5% - 2.5% 74 5300 96 21 27 3 DES23030 90% - 10% 65 4200 115 34 26 4 DES23046 85% - 15% 59 3700 90 25 31 5 DES23032 80% - 20% 55 3400 91 25 31 6 DES22099 0% - 100% 27 3 300 97 54 31

[0100] Example 1 (DES23007): Preparation of a polyester from 50.18 g (0.288 mol) of sebacic acid and 50.19 g (0.288 mol) of 1-10 decanediol

[0101] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 hours. The mixture is then placed under vacuum for 24 hours at 140°C with magnetic stirring. A second 6-hour step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 7000 g / mol and a mass-average molar mass (Mw) of 16000 g / mol.

[0102] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 77°C and an enthalpy of fusion measured at approximately 299.6 J / g.

[0103] The surface energy of the polyester is calculated using the Owens-Wendt method. For said polyester, the calculated value is 30 mJ / m². The contact angle of the water on the surface of the polyester is 115°. The contact angle of the olive oil is measured at 16°.

[0104] Polyester allows for the structuring of different oils with different polarities, such as castor oil, sunflower oil, Cetiol® C5C, and CCT (capric caprylic triglyceride), at a low concentration of 4% by weight. According to this method, polyester is added to the aforementioned oils, thus forming a network crystalline structure that solidifies oils at this concentration.

[0105] Example 2 (DES23024): Preparation of a polyester from 50.35 g (0.249 mol) of sebacic acid, 41.22 g (0.236 mol) of 1,10 decanediol and 4.46 g (0.012 mol) of glycerol monostearate

[0106] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 hours. The mixture is then placed under vacuum for 24 hours at 140°C with magnetic stirring. A second 6-hour step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 5300 g / mol and a mass-average molar mass (Mw) of 12200 g / mol.

[0107] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 74°C and an enthalpy of fusion measured at approximately 132.5 J / g.

[0108] The surface energy of the polyester is calculated using the Owens-Wendt method. For said polyester, the calculated value is 27 mJ / m². The contact angle of the water on the surface of the polyester is 96°. The contact angle of the olive oil is measured at 21°.

[0109] Polyester enables the structuring of various oils with different polarities, such as castor oil, sunflower oil, Cetiol® C5C, and CCT, at a low concentration of 4% by weight. According to this method, polyester is added to the aforementioned oils, thus forming a crystalline network that solidifies the oils at this concentration.

[0110] Example 3 (DES23030): Preparation of a polyester from 50 g (0.247 mol) of sebacic acid, 34.44 g (0.197 mol) of 1,10-decanediol and 17.71 g (0.049 mol) of glycerol monostearate

[0111] These precursors are placed in a 250 mL round-bottom flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 8-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 4200 g / mol and a mass-average molar mass (Mw) of 10100 g / mol.

[0112] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 65°C and an enthalpy of fusion measured at approximately 81 J / g.

[0113] The surface energy of the polyester is calculated using the Owens-Wendt method. For said polyester, the calculated value is 26 mJ / m². The angle of contact of the water on The surface of the polyester is 115°. The contact angle of the olive oil is measured at 34°.

[0114] Polyester enables the structuring of various oils with different polarities, such as castor oil, sunflower oil, Cetiol® C5C, and CCT, at a low concentration of 4% by weight. According to this method, polyester is added to the aforementioned oils, thus forming a crystalline network that solidifies the oils at this concentration.

[0115] Example 4 (DES23046): Preparation of a polyester from 47.18 g (0.233 mol) of sebacic acid, 28.46 g (0.163 mol) of 1,10-decanediol and 25.1 g (0.070 mol) of glycerol monostearate

[0116] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 8-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 3700 g / mol and a mass-average molar mass (Mw) of 10600 g / mol.

[0117] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 60°C and an enthalpy of fusion measured at approximately 109 J / g.

[0118] The surface energy of the polyester is calculated using the Owens-Wendt method. For said polyester, the calculated value is 31 mJ / m². The contact angle of the water on the surface of the polyester is 80°. The contact angle of the olive oil is measured at 25°.

[0119] Polyester enables the structuring of various oils with different polarities, such as castor oil, sunflower oil, Cetiol® C5C, and CCT, at a low concentration of 4% by weight. According to this method, polyester is added to the aforementioned oils, thus forming a crystalline network that solidifies the oils at this concentration.

[0120] Example 5 (DES23032): Preparation of a polyester from 38.52 g (0.190 mol) of sebacic acid, 27.32 g (0.076 mol) of glycerol monostearate and 19.86 g (0.114 mol) of 1,10 decanediol

[0121] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 8-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 3400 g / mol and a mass average molar mass (Mw) of 8800 g / mol.

[0122] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 55°C and an enthalpy of fusion measured at approximately 101 J / g.

[0123] The surface energy of the polyester is calculated using the Owens-Wendt method. For said polyester, the calculated value is 31 mJ / m². The contact angle of the water on the surface of the polyester is 91°. The contact angle of the olive oil is measured at 25°.

[0124] Polyester enables the structuring of various oils with different polarities, such as castor oil, sunflower oil, Cetiol® C5C, and CCT, at a low concentration of 4% by weight. According to this method, polyester is added to the aforementioned oils, thus forming a crystalline network that solidifies the oils at this concentration.

[0125] Comparative example 6 (DES22099): Preparation of a polyester from 12.99 g (0.064 mol) of sebacic acid, 29.96 g (0.083 mol) of glycerol monostearate

[0126] These precursors are placed in a 250 mL round-bottom flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 8-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 3300 g / mol and a mass-average molar mass (Mw) of 12000 g / mol.

[0127] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting point of approximately 38°C. The surface energy of polyester is calculated using the Owens-Wendt method. For this polyester, the calculated value is 31 mJ / m². The contact angle of water on the polyester surface is 97°. The contact angle of olive oil is measured at 54°.

[0128] Table 2 below indicates the characteristics of the polymers according to the invention, the preparation of which is given in examples 7 and 8.

[0129] [Tables2] Variations C10-C10-DHHCA (hydrogenated caffeic acid) (mol%) Example No. Reaction SC10-DHHCA Tf (°C) Mn (g / mol) ^water (°) ^oil (°) Es (mJ / m2) 7 DES23012 97.5% - 2.5% 74 5000 99 16 26 8 DES23037 95% - 5% 69 6900 82 13 34

[0130] Example 7 (DES23012): Preparation of a polyester from 49.13 g (0.243 mol) of sebacic acid, 2.18 g (0.012 mol) of hydrogenated caffeic acid, 1.1 g (0.012 mol) of glycerol and 40.3 g (0.231 mol) of 1,10 decanediol

[0131] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 hours. The mixture is then placed under vacuum for 19 hours at 140°C with magnetic stirring. The CES indicates a number-average molar mass (Mn) of 5000 g / mol and a mass-average molar mass (Mw) of 12000 g / mol.

[0132] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 74°C. The surface energy of polyester is calculated using the Owens-Wendt method. For this polyester, the calculated value is 26 mJ / m². The contact angle of water on the polyester surface is 99°. The contact angle of olive oil is measured at 16°.

[0133] Polyester allows for the structuring of various oils with different polarities, such as castor oil, sunflower oil, Cetiol® C5C, and CCT, at a low concentration of 4% by weight. According to this method, polyester is added to the aforementioned oils, thus forming a crystalline network that solidifies the oils at this concentration.

[0134] Example 8 (DES23037) Preparation of a polyester from 33.16 g (0.164 mol) of sebacic acid, 3 g (0.0164 mol) of hydrogenated caffeic acid, 25.78 g (0.147 mol) of 1,10-decanediol and 1.51 g (0.0164 mol) of glycerol

[0135] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 hours. The mixture is then placed under vacuum for 20 hours at 140°C with magnetic stirring. A second 6-hour step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 6900 g / mol and a mass-average molar mass (Mw) of 17900 g / mol.

[0136] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 65°C. The surface energy of polyester is calculated using the Owens-Wendt method. For this polyester, the calculated value is 34 mJ / m². The contact angle of the water on the polyester surface is 82°.

[0137] Table 3 below shows the characteristics of the polymers in Examples 9 to 11.

[0138] [Tables3] Variations C10-C10-2.5% M (%mole) Example No. Reaction M Tf (°C) Mn (g / mol) Û ^water (°) ^oil (°) Es (mJ / m2) 9 DES23068 Pripol® 1009 73 4 500 87 16 30 10 DES23083 Prica®100H 71 6 000 92 15 29 11 DES23087 Glycerol monolaurate 73 6 000 80 21 32

[0139] Example 9 (DES23068): Preparation of a polyester from 73.27 g (0.362 mol) of sebacic acid, 60 g (0.344 mol) of 1,10-decanediol and 9.8 g (0.018 mol) of Pripol 2033

[0140] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 6-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 4500 g / mol and a mass-average molar mass (Mw) of 12700 g / mol.

[0141] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 73°C and a measured enthalpy of fusion of approximately 122.7 J / g.

[0142] Example 10 (DES23083): Preparation of a polyester from 50 g (0.282 mol) of sebacic acid, 49.12 g (0.296 mol) of 1,10-decanediol and 30.81 g (0.014 mol) of Prica 100H

[0143] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 7-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 6000 g / mol and a mass-average molar mass (Mw) of 10200 g / mol.

[0144] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 71°C and an enthalpy of fusion measured at approximately 100.4 J / g.

[0145] Example 11 (DES23087): Preparation of a polyester from 62.96 g (0.311 mol) of sebacic acid, 51.66 g (0.296 mol) of 1-10 decanediol and 4.3 g (0.016 mole) of glycerol monolaurate

[0146] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. A second 7-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 6000 g / mol and a mass-average molar mass (Mw) of 12100 g / mol.

[0147] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 73°C and an enthalpy of fusion measured at approximately 131 J / g.

[0148] Table 4 below shows the characteristics of the polymers in Examples 12 to 14.

[0149] [Tables4] Variations C10-C10-C18-DHHCA (%mol) Example No. Reaction SC10-C18-DHHCA Tf (°C) Mn (g / mol) ^water (°) ^oil (°) Es (mJ / m2) 12 DES23040 87.5 : 10 : 2.5 61 4000 97 56 21 13 DES23042 89.5 : 10 : 0.5 64 4100 93 52 23 14 DES23046 84.5 : 15 : 0.5 59 4300 92 42 25

[0150] Example 12 (DES23040): Preparation of a polyester from 44.36 g (0.219 mol) of sebacic acid, 2 g (0.01 mol) of hydrogenated caffeic acid, 28.68 g (0.164 mol) of 1,10-decanediol, 15.74 g (0.044 mol) of glycerol monostearate and 1 g (0.01 mol) of glycerol

[0151] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 hours. The mixture is then placed under vacuum for 27 hours at 140°C with magnetic stirring. A second 6-hour step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography with polystyrene calibration (SEC) by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 4000 g / mol and a mass-average molar mass (Mw) of 12680 g / mol.

[0152] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 61°C and an enthalpy of fusion measured at approximately 62 J / g.

[0153] Example 13 (DES23042): Preparation of a polyester from 28.3 g (0.140 mol) of sebacic acid, 0.25 g (0.001 mol) of caffeic acid, 10 g (0.028 mol) of mono glycerol stearate, 19.25 g (0.111 mole) of 1,10-decanediol and 0.13 g (0.001 mole) of glycerol

[0154] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 h. The mixture is then placed under vacuum for 16 h at 140°C with magnetic stirring. A second 12-h step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 4100 g / mol and a mass-average molar mass (Mw) of 11400 g / mol.

[0155] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 64°C and an enthalpy of fusion measured at approximately 90 J / g.

[0156] Example 14 (DES23046): Preparation of a polyester from 27.3 g (0.135 mol) of sebacic acid, 0.25 g (0.001 mol) of hydrogenated caffeic acid, 12.76 g (0.035 mol) of glycerol monostearate, 16.5 g (0.094 mol) of 1,10-decanediol and 0.12 g (0.001 mol) of glycerol

[0157] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 2 hours. The mixture is then placed under vacuum for 20 h at 140°C with magnetic stirring. A second 8-hour step is then carried out at 180°C under vacuum. The reaction is monitored by size-exclusion chromatography with polystyrene calibration by progressively increasing molar mass. The CES indicates a number-average molar mass (Mn) of 4300 g / mol and a mass-average molar mass (Mw) of 15230 g / mol.

[0158] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 59°C and an enthalpy of fusion measured at approximately 109 J / g.

[0159] Table 5 below shows the characteristics of the polymers in comparative examples 15 to 18.

[0160] [Tables5] Comparative Examples Example No. Reaction Composition (mol%) Tf(°C) 15 DES23014 CIO: Glycerol: DHHCA (48.8: 48.8: 2.4) 6 16 DES23015 CIO: Glycerol: Glyceryl monostearate: DHHCA (49: 2.4: 46.2: 2.4) 24 17 DES22036 CIO: Pripol 1009 (50: 50) - 8 18 DES22087 CIO: Pripol 1009: Glyceryl monostearate (39: 4: 57) 25

[0161] Comparative example 15 (DES23014): Preparation of a polyester from 66.58 g (0.329 mol) of sebacic acid, 3 g (0.016 mol) of hydrogenated caffeic acid and 30.33 g (0.329 mol) of glycerol

[0162] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 2500 g / mol and a mass-average molar mass (Mw) of 14000 g / mol.

[0163] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting point of approximately 22°C.

[0164] Comparative Example 16 (DES23015): Preparation of a polyester from 33.29 g (0.164 mol) of sebacic acid, 3 g (0.008 mol) of hydrogenated caffeic acid, 55.76 g (0.155 mol) of glycerol monostearate and 0.79 g (0.008 mol) of glycerol

[0165] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 3250 g / mol and a mass-average molar mass (Mw) of 10900 g / mol.

[0166] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 24°C.

[0167] Comparative Example 17 (DES22036): Preparation of a polyester of 41.30 g (0.072 mol) of Pripol 1009, 12.52 g (0.072 mol) of 1-10 decanediol

[0168] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 14 h at 140°C with magnetic stirring. The reaction is monitored by size-exclusion chromatography (SEC) with polystyrene calibration by progressively increasing molar mass. The SEC indicates a number-average molar mass (Mn) of 5600 g / mol and a mass-average molar mass (Mw) of 9890 g / mol.

[0169] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately -8°C.

[0170] Comparative example 18 (DES22087): Preparation of a polyester from 25 g (0.0697 mol) of glycerol monostearate, 3.08 g (0.005 mol) of Pripol 1009 and 9.76 g (0.048 mol) of sebacic acid

[0171] These precursors are placed in a 250 mL flask. The reaction mixture is stirred magnetically at 140°C under nitrogen for 1 h. The mixture is then placed under vacuum for 24 h at 140°C with magnetic stirring. The reaction is monitored by size-exclusion chromatography with polystyrene calibration by progressively increasing molar mass. The CES indicates a number-average molar mass (Mn) of 4300 g / mol and a mass-average molar mass (Mw) of 9000 g / mol.

[0172] The morphology of the polyester is studied by differential scanning calorimetry. The results obtained indicate that said polyester has a melting temperature of approximately 44°C. The surface energy of polyester is calculated using the Owens-Wendt method. For this polyester, the calculated value is 23 mJ / m². The contact angle of the water on the polyester surface is 83°. Example 19: Cosmetic formulations

[0173] For each type of formulation, the polyesters will be compared to a positive reference (a commercial brand ANTARON VP-220F: VP / Eicosene Copolymer) and to a negative reference (without added film-forming agent). Unless otherwise stated, percentages are expressed as mass percentages (% g / g of formulation).

[0174] Formulation 1: foundation formulated as an inverse emulsion The inverse emulsion foundation is formulated as follows: the aqueous phase (A) is prepared under moderate magnetic stirring. The film-forming agent is mixed with the pigment dispersion at 80°C. This phase (B) is cooled to temperature ambient temperature and phase (C) is then added. The addition of phase (A) to phase (B+C) is carried out gradually at room temperature under vigorous mechanical stirring by a deflocculating blade. Stirring is continued for 15 min and phases D and E are added under gentler stirring. The composition of formulation 1 is given in Table 6 below:

[0175] [Tableauxô] Phase Nom commercial Dénomination INCI Formule A Formule B Formule C A DEMINERALIZ ED WATER Water 46,50 46,50 46,50 A NaCl Sodium Chloride 1,00 1,00 1,00 A GLYCERIN Glycerin 5,00 5,00 5,00 B AGENT FILMOGENE DES23007 (exemple 1) ou DES22036 (exemple 17) ou DES22087 (exemple 18) ou DES23015 (exemple 16) ou DES23030 (exemple 3) ou DES23012 (exemple 7) X 3,00 X B ANTARON VP-220F VP / Eicosene Copolymer X X 3,00 B DISPERSION FEA22073 Caprylic / Capric Triglycéride (and) Titanium Dioxide (and) Iron Oxides (and) Po-lyhydroxy Stearic Acid 25,00 25,00 25,00 B CETIOL®CC Dicaprylyl Carbonate 10,00 10,00 10,00 C PLUROL DIL SOSTEARIQUE CG Polyglyceryl-3 Dii-so stéarate 2,00 2,00 2,00 C DEHYMULS PGPH Polyglyceryl-2 Dipoly-hydroxystearate 2,00 2,00 2,00 D SATINIER M5 Silica 5,00 5,00 5,00 E PARFUM Fragrance 0,50 0,50 0,50 TOTAL 100,00 100,00 100,00

[0176] The semi-crystalline polyester according to the invention, obtained from bio-based derivatives, allows good stabilization of inverse emulsions.

[0177] Formulation 2: Foundation formulated in an anhydrous formulation The anhydrous foundation is formulated as follows: Phase (A) is prepared beforehand by mixing the three oils with a pigment cocktail under vigorous stirring with Ultra-Turrax for 15 minutes. Phase (B) is added, and the mixture is heated to 80°C and homogenized for 30 minutes under mechanical stirring. The temperature is lowered to 80°C, and Phase (C) is added, followed by stirring for 5 minutes. Finally, Phase (D) is added, and the complete mixture is stirred for an additional 5 minutes.

[0178] The composition of formulation 2 is given in Table 7 below:

[0179] [Tables?] Nom commercial Dénomination INCI Formulatio n D Formulatio n E Formulatio n F Formulatio n G Labrafac CC Caprylic / Capric Triglycéride 34,00 31,00 31,00 31,00 Huile de Ricin Ricinus Communis (Castor) Seed Oil 32,50 32,50 32,50 32,50 Cetiol C5 C Coco-Caprylate Caprate 5,00 5,00 5,00 5,00 Unipure CI 77891 10,00 10,00 10,00 10,00 EstoGel Max Castor Oil / IPDI Copolymer (and) Caprylic / Capric Triglycéride (and) Hydrogenated Castor Oil / Sebacic Acid Copolymer 6,00 6,00 6,00 6,00 Cire de Riz Oryza Sativa (Rice) Bran Wax 7,00 7,00 7,00 7,00 Salacos HS-6C Polyhydroxy Stearic Acid 1,00 1,00 1,00 1,00 Satinier M5 Silica 4,00 4,00 4,00 4,00 Vanille Gourmande Fragrance 0,50 0,50 0,50 0,50 Agent Filmogène DES23024 (exemple 2) X 3,00 X X Antaron V220 VP / Eicosene Copolymer X X 3,00 X Solamaz Diisostearoyl Polyglyceryl-3 Dimer Dilinoleate (and) Caprylic / Capric X X X 3,00 Triglycéride

[0180] Semi-crystalline polyester, obtained from bio-based derivatives, provides consistency and good sensory appeal.

[0181] Formulation 3: lipstick formulated on an anhydrous base Anhydrous lipstick is formulated as follows: all constituents are mixed for 30 min at 80°C under mechanical agitation by a deflocculating blade. The composition of formulation 3 is given in Table 8 below:

[0182] [Tables8] Trade Name INCI Name Formulation H Formulation I Formulation J RICE WAX Oryza Sativa (Rice) Bran Wax 10.00 10.00 10.40 BEESWAX Cera Alba 10.00 10.00 10.40 SWD RED 6 BA LAKE Synthetic Wax (and) CI 15850 15.00 15.00 15.60 LABRAFAC CC Caprylic / Capric Triglyceride 61.00 61.00 63.5 Film-Forming Agent DES23024 (example 2) 4.00 XX ANTARON V220 VP / Hexadecene Copolymer X 4.00 X Total 100 100 100

[0183] Formulation 4: SPF30 sunscreen The sunscreen is formulated as follows: Phase (A) is prepared at room temperature with moderate mechanical stirring. Glycerin and xanthan gum are mixed beforehand before being added to phase (A). Phase (A) is then heated to 80°C. The oil phase (B) is prepared at 80°C with mechanical stirring using a deflocculating blade. Emulsification is achieved by adding phase (B) to phase (A) at 80°C with vigorous stirring. Stirring is maintained for 15 minutes at 80°C. The temperature is then lowered to 40°C and the fragrance (C) is added. Stirring continues until the formulation returns to room temperature. The composition of formulation 4 is given in Table 9 below:

[0184] [Tables9] Phase Nom commercial Dénomination INCI Formule K (%) Formule L(%) Formule M (%) A Eau déminéralisée Water 53,60 53,60 53,60 A Phenoxyethanol Phenoxyethanol 0,60 0,60 0,60 A Glycérine Glycerin 3,00 3,00 3,00 A Rhodicare S Xanthan gum 0,30 0,30 0,30 B Sans polymère X X X B Antaron V-220F VP / Eicosene Copolymer X 3,00 X B AGENT FILMOGENE DES23024 (exemple 2) X X 3,00 B 2- Ethylhexyl salicylate Ethylhexyl salicylate 5,00 5,00 5,00 B Uvinul T150 Ethylhexyl triazone 4,00 4,00 4,00 B Uvinul A plus granular Diethylamino hydroxybenzoyl hexyl benzoate 4,00 4,00 4,00 B Tinosorb B Bis-ethylhexyloxyphenol Methoxyphenyl triazine 3,00 3,00 3,00 B Dub DIS Diisopropyl sebacate 11,00 11,00 11,00 B Cetiol B Dibutyl adipate 9,00 9,00 9,00 B Tego Care PB S 6 Polyglyceryl-6 stéarate (and) polyglyceryl-6 behenate 4,00 4,00 4,00 B Tegin Pellets Glyceryl stéarate 1,00 1,00 1,00 B Lanette 0 OR Cetearyl alcohohl 1,00 1,00 1,00 C Parfum Manoi Fragrance 0,50 0,50 0,50 Total 100,00 100,00 100,00

[0185] Example 20: Test of the anti-transfer property The anti-transfer property is evaluated through several tests on cosmetic color formulations. The performance of the polyesters according to the invention is assessed in formulations of different types (foundations, lipsticks). Foundation transfer resistance test

[0186] Test No. 1: The formulation is applied to BioSkin® at a concentration of 5 mg / cm². The formulation is spread with a finger according to the established protocol. The formulation film is dried for 15 min at 25°C. At the end of the drying period, a piece of paper is placed on the film and a force of 5 N / cm² is applied to the paper for 3 seconds. The transfer is evaluated visually and quantitatively by measuring the mass gain on the paper after applying a force of 5 N / cm² for 3 s.

[0187] The percentage of formulation transferred is then calculated using the formula: (mass of paper before - mass of paper after) / mass of formulation deposited

[0188] The results of the anti-transfer tests according to Test No. 1 with inverse emulsion foundations [Table 6] are reported in Table 10 below:

[0189] [TableauxlO] Formulation Number Formula C Formulation B Formula A Film-forming agent Vp / Eicosene Copolymer (Antaron VP-220F) DES23007 (example 1) DES22036 (comparative example 17) DES22087 (comparative example 18) Polymer-free Percentage of formulation transferred 3%-10% 4%-10% 24-27% 24-25% 25-31%

[0190] The results show that a polyester according to the invention formulated in an inverse emulsion foundation exhibits pigment transfer similar to the synthetic commercial reference VP / Eicosene Copolymer. In contrast, the polyesters in the comparative examples exhibit poor anti-transfer properties, close to those of the polymer-free formulation. DES22036 polyester (comparative example 17) is a liquid polyester, which therefore does not have a melting temperature above ambient; it has a transfer percentage of about 25% under the test conditions. The DES22087 polyester (comparative example 18) contains a significant amount of hydrophobic grafts and has a low melting point (Tf) of 25°C, resulting in limited cohesion of the deposited film. Under the test conditions, the film exhibits a transfer rate of approximately 25%.

[0191] The results of the anti-transfer tests according to Test No. 1 modified in that they are conducted at 25°C after a 25-minute drying period with inverse emulsion foundations [Table 6] are reported in Table 11 below:

[0192] [Tableauxll] Formulation Number Formula C Formula B Formula A Film-forming agent VP / Eicosene Copolymer (Antaron V-220F) DES22007 (Example 1) DES23030 (Example 3) DES23015 (Comparative Example 16) Polymer-free Percentage of formulation transferred 3% - 10% 5% - 10% <10% <35% <25%

[0193] The results show that the polyesters according to the invention formulated in an inverse emulsion foundation exhibit pigment transfer similar to the synthetic commercial reference VP / Eicoseine Copolymer.

[0194] The DES22015 polyester (comparative example 18) is a polyester containing a significant amount of hydrophobic grafts and a low Tf (25°C), which gives limited cohesion to the deposited film. It exhibits a transfer percentage close to that of the polymer-free formula.

[0195] Test No. 2: This anti-transfer property test was designed to study the property in a temperature range close to that of the skin (30°C). It reproduces the conditions of Test No. 1 on BioSkin®, but drying is carried out for 30 minutes at 30°C / 35°C, followed by the test performed at 30°C / 35°C.

[0196] The results of the anti-transfer tests according to Test No. 2 with inverse emulsion foundations [Table 6] are reported in Table 12 below:

[0197] [Tables 12] Formulation Number Formula C Formula B Formula A Film-forming agent VP Eicosene Copolymer (Antaron V-220F) DES23030 (Example 3) DES23024 (Example 2) Polymer-free Percentage of formulation transferred 12-15% 0-1% <1% 7-10%

[0198] The results show that, for the formulation containing the film-forming polyester according to the invention, the percentage of product transferred is considerably reduced compared to the same test carried out at a lower temperature (25°C) For the formulation containing the synthetic commercial product, an increase in the amount of product transferred is observed. This petroleum-based film-forming agent has a temperature close to that of the test, around 35°C-40°C. Consequently, the inter-chain interactions and the organization of the crystalline zones, which usually give rise to film-forming properties, are reduced; the film-forming agent is less effective. The results therefore show that, at a temperature of 30-35°C, the polyesters according to the invention exhibit, due to their higher melting temperature (50-80°C), a better anti-transfer property.

[0199] Test No. 3: This test consists of depositing a 30 mg mass of formulation onto a 4 cm² area of ​​a volunteer's skin and allowing the film to dry for 30 minutes. A constant force of 5 N / cm² is then applied to the same area. The amount of formulation transferred is quantified by measuring the mass loss.

[0200] The results of the anti-transfer tests according to Test No. 3 with inverse emulsion foundations [Table 6] are reported in Table 13 below:

[0201] [Tables 13] Formulation Number Formula B Formula C Formula A Film-forming agent DES23007 (example 1) DES23012 (example 7) VP / Eicosene Copolymer (Antaron V-220F) Polymer-free Formulation amount transferred to paper 2.2 mg 2.3 mg 3.9 mg 4.5 mg

[0202] The results show that the film-forming polyesters according to the invention exhibit a significant anti-transfer effect when incorporated into foundation formulations.

[0203] The results of the anti-transfer tests according to Test No. 3 with anhydrous foundations [Formula 2 - Table 7] are reported in Table 14 below:

[0204] [Tables 14] Formulation Number Formula D Formula E Formula F Formula G Film-forming agent Polymer-free DES23024 (example 2) VP / Eicosene Copolymer (Antaron V-220F) Diisostearoyl Polyglyceryl-3 Dimer Dilinoleate (and) Caprylic / Capric Triglyceride (Solamaz) Test Temperature 25°C 25°C 25°C 25°C Percentage of formulation transferred 20% - 30% 10% - 20% 10% - 16% 30% - 40%

[0205] The results show that the commercial bio-based liquid film-forming agent has no anti-transfer properties, whereas the bio-based film-forming agent of the invention is as effective as the synthetic commercial reference. Lipstick transfer resistance test

[0206] The lipstick formulation [Example 19, Formulation 3 - Table 8] is applied to BioSkin® at a concentration of 5 mg / cm², according to the conditions of Test No. L

[0207] The results are reported in Table 15 below:

[0208] [Tables 15] Formulation Number Formula H Formula I Formula J Film-forming agent DES23030 (Example 3) VP / Eicosene Copolymer (Antaron V-220F) Polymer-free Percentage of formulation transferred 2% - 4% 3% - 5% 8-10%

[0209] The results show that a polyester according to the invention formulated in a lipstick exhibits pigment transfer similar to the commercial reference of petrochemical origin (Antaron V-220F). The difference in transfer observed with and without a film-forming agent is significantly visible.

[0210] Example 21: Water resistance test In vivo water resistance tests are performed. The protocol consists of applying a known quantity of the formulation to the hands of a volunteer. The cream is applied to the back of one hand, and both hands are then rubbed back-to-palm for 10 seconds. The applied formulation is dried for 15 minutes at room temperature. Both hands are then each immersed in a beaker containing 500 mL of water. The mixture is stirred at 100 rpm using a magnetic stir bar and a magnetic stirrer, and the baths are heated to 30°C. A 10-minute or 20-minute exposure in this medium is then performed. The amount of filter released is measured by UV absorption spectroscopy. It is calculated by comparing the absorbance of the filters at 305 nm and 355 nm from the fully solubilized formulation (Ai00%) to that of the filters released after application to hands and soaking. The lower the concentration of filters in the aqueous solution, the more water-resistant the formulation can be considered. A UV photograph of the hands is taken before and after exposure in water baths to qualitatively assess the loss or not of organic sunscreens. A UV photograph produces a black coloration in areas that absorb UV radiation. Since organic filters absorb these wavelengths, if such filters are present, the skin appears black.

[0211] Test 1: To test water resistance, the sunscreen formulation [Formulation 4 - Table 9] is used. The water resistance of three oil-in-water emulsions containing polymer-free organic UV filters, formulated with Antaron® V-220F (synthetic commercial reference), and with a film-forming polyester according to the invention is evaluated. For this test, only 10 minutes of exposure in water are carried out, but without magnetic stirring. The results are reported in Table 16 below:

[0212] [Tables 16] Formulation Number Formula K Formula L Formula M Film-forming agent Polymer-free VP / Eicosene Copolymer (Antaron V-220F) DES23024 (example 2) Amount of formulation applied 400 mg 399 mg 397 mg Absorbance (305 nm) 0.043 0 0 Absorbance (355 nm) 0.15 0 0 Released formulation (305 nm) 2.2% 0 0 (355 nm) 11% 0 0

[0213] Aioo% (305nm) = 2; AiOo% (355nm)=l.35

[0214] The results show that the quantity of filters released by the formulation containing the bio-based polymer of the invention is zero, and identical to that of the commercial reference.

[0215] Test 2: The water resistance of two sunscreen formulations [Formulation 4 - Table 9], formulated with a film-forming polyester according to the invention and with Antaron® V220F (trademark), is evaluated after only 10 minutes of exposure in water but under agitation with a magnetic stir bar. The results are reported in Table 17 below:

[0216] [Tables 17] Formulation Number Formula M Formula L Film-forming agent DES23024 (example 2) VP / Eicosene Copolymer (Antaron V-220F) Amount of formulation applied 394 mg 395 mg Absorbance (305 nm) 0.05 0.01 Absorbance (355 nm) 0.005 0.035 Released formulation (305 nm) 2.5% 0.5% (355 nm) 0.3% 2.5%

[0217] Aioo% (305nm) = 2; AiOo% (355nm)=l.35

[0218] Test 3: Water resistance of two sunscreen formulations [Formulation 4 - Table 9], formulated with a film-forming polyester according to the invention and with Antaron® V220F (trademark) is evaluated after 20 min of exposure in water, but under the agitation of a magnetic stir bar. The results are reported in Table 18 below:

[0219] [Tables 18] Formulation Number Formula K Formula L Formula M Film-forming agent Polymer-free base VP / Eicosene Copolymer (Antaron V-220F) DES23024 (example 2) Amount of formulation applied 403 mg 402 mg 398 mg Absorbance (305 nm) 0.280 0.015 0.015 Absorbance (355 nm) 0.203 0 0% Formulation released (305 nm) (355 nm) 14% 15% 0.8% 0% 0.8% 0%

[0220] Aioo% (305nm) = 2; AiOo% (355nm)=l.35

[0221] The results, also shown in [Fig. 1], demonstrate that the quantity of filters released by the formulation containing the bio-based polymer of the invention under agitation is significantly lower than that of the base without the polymer, and comparable to the result obtained with the synthetic polymer. The bio-based polymer of the invention exhibits proven water-resistant properties.

Claims

1. Claims Bio-sourced crystalline and / or semi-crystalline polyester compound capable of forming a film, characterized in that it corresponds to formula (I) [Chem.l] (I) in which: - W and X, identical or different, independently represent a linear or cyclic aliphatic alkyl radical, comprising from 2 to 36 carbon atoms, preferably from 4 to 28 carbon atoms, said radical optionally comprising one or more unsaturations but not including any ether, amine or thiol function; - Z represents a linear or branched, or cyclic, aliphatic alkyl radical comprising from 2 to 36 carbon atoms, preferably from 4 to 28 carbon atoms, said radical optionally comprising one or more unsaturations but not including any ether, amine or thiol function; - Y represents a branched aliphatic alkyl radical, comprising from 3 to 36 carbon atoms, preferably from 4 to 31 carbon atoms, said radical optionally comprising one or more unsaturations but not including any ether, amine or thiol function, - V represents a branched or cyclic aliphatic or aromatic alkyl radical comprising from 3 to 90 carbon atoms, preferably from 6 to 75 atoms, but not including any ether, amine or thiol function, - Ri represents a proton H or an acyl-(C=O)R group, where R is a linear, branched or cyclic aliphatic alkyl radical comprising from 2 to 90 carbon atoms, said radical possibly comprising unsaturations and one or more alcohol or acid type functions; - R2 represents an -OH group or an -OR termination where R', identical to or different from R, is an aliphatic, linear, branched or cyclic alkyl radical comprising from 2 to 36 carbon atoms, said radical possibly comprising unsaturations and one or more alcohol or acid type functions. - n, m and p represent, independently, an integer whose sum (n+m+p) is such that the number-average molar mass of the polymer is between 3000g / mol and 50000g / mol; - n is an integer from 1 to 400; - m is an integer from 0 to 160 and chosen so that the ratio (m / n+m+p) is between 0 and 0.4; - p is an integer from 0 to 20 and chosen so that the ratio (p / n+m+p) is between 0 and 0.05, and having the following characteristics: - it is made up of monomer units of biosourced origin; - its melting temperature is between 50°C and 80°C; - it has a surface free energy of less than 35 mJ / m2; - it has a number-average molar mass greater than or equal to 3000 g / mol and less than 50000 g / mol, preferably a number-average molar mass of between 3000 and 40000 g / mol; - it has a water contact angle of between 80° and 150°, and - it has an oil contact angle of between 15° and 90°.

2. Polyester compound according to claim 1, characterized in that it has a number-average molar mass of between 3000 and 30000 g / mol, in particular between 3000 and 10000 g / mol, more particularly between 4000 and 7000 g / mol.

3. Polyester compound according to one of claims 1 or 2, characterized in that it has a water contact angle of between 80° and 120°, preferably between 80° and 100°.

4. Polyester compound according to one of claims 1 to 3, of formula (I), in which W and X are identical linear or cyclic alkyl radicals, comprising 4 to 28 carbon atoms and will represent at least 80 mol% of the polymer structure.

5. Polyester compound according to one of claims 1 to 4, of formula (I), in which Y is derived from branched polyol monomers containing 3 to 36 carbon atoms, preferably 4 to 31 atoms and is present in said polyester compound in an amount of between 0 and 40 mol%.

6. A polyester compound according to claim 5, of formula (I), in which Y comprises a branched chain of 21 carbon atoms.

7. Polyester compound according to one of claims 1 to 6, of formula (I), in which V is derived from branched fatty chain polyol monomers, such as hydroxylated fatty acid dimers or oligopolyesters, comprising 3 to 90 carbon atoms, preferably 6 to 75 carbon atoms. carbon.

8. Polyester compound according to one of claims 1 to 7, of formula (I), in which V is present in said polyester compound in an amount of between 0 and 5 mol%.

9. Polyester compound according to one of claims 1 to 8, of formula (I), containing catechol units introduced when Ri is chosen from catechol derivatives, or when V is derived from polyol monomers containing catechol-type units and is present in said polyester compound in an amount of between 0 and 5 mol%.

10. Process for preparing a polyester compound according to any one of claims 1 to 9, characterized in that it comprises the following steps: - formation of an oligomer by condensation between at least one polyacid and at least one polyalcohol for a period of between 1 h and 35 h, at a temperature of between 100°C and 180°C, in particular between 130°C and 160°C, under vacuum, and - complete polymerization between the previously formed oligomers, for a period of between 1 h and 15 h, at a temperature of between 150°C and 215°C, under vacuum.

11. Use of a polyester compound according to any one of claims 1 to 9 or obtained by the process according to claim 10, in a cosmetic formulation, in particular a direct emulsion (oil / water), an inverse emulsion (water / oil) or an anhydrous formulation.

12. Use according to claim 11, wherein said polyester compound is used in admixture with an oil chosen from vegetable oils and mixtures of apolar oils and more polar oils, in particular of natural origin.

13. Cosmetic composition containing a polyester compound according to any one of claims 1 to 9 or obtained by the process according to claim 10.

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