EP1732964A2 - Sequenced copolymer - Google Patents

Abstract

The invention relates to a sequenced copolymer, to a composition comprising said copolymer, and to a cosmetic treatment method. The invention especially relates to a linear, ethylenic, sequenced copolymer containing at least one ionic hydrophilic pattern in each sequence. Said pattern can be different from one sequence to the next, and each sequence contains between 2 and 100 wt. % thereof in relation to the weight of said sequence. The invention also relates to a cosmetic or pharmaceutical composition comprising one such copolymer, and to a cosmetic make-up method or a care method for keratin materials using said composition.

Description

 COPOLYMER SEQUENCE, COMPOSITION COMPRISING SAME AND COSMETIC TREATMENT METHOD

The present invention relates to new block copolymers, to their use in the cosmetic field in particular, as well as to the compositions comprising them.

In the cosmetic field, polymers with antinomic properties are often sought: obtaining good fixation without tacky; good resistance of products to humidity with good elimination in shampoo; or a makeup composition combining comfort and hold. Furthermore, these polymers should preferably be transported in water, in soluble or dispersible form. This is the reason why the formulators have turned more particularly to copolymers, and in particular to block polymers or block polymers, which have advantageous mechanical properties. They can in particular allow these antithetical properties to be obtained, because they result from the association, within the same chain, of sequences of different properties: one which can provide rigidity and the other flexibility, for example . Thus, the styling properties of styling products or lacquers can be modulated. This also makes it possible, in the case of nail varnishes, to optimize the wear resistance and the adhesion of the films to the nail, without generating sticky surface films. For this, within the same chain, we can associate a sequence providing adhesion and a sequence avoiding tights. In the cosmetic field, copolymers based on POE-PPO (polyethylene oxide / polypropylene oxide) are known more particularly as block copolymers which can be transported in water. However, these polymers do not have satisfactory mechanical properties. In particular, they do not bring any outfit to the hairstyle.

Among the other block copolymers which can be transported in water, mention may be made of those described in application O02 / 28358. In particular, block copolymers are described, a block of which is a copolymer mainly comprising nonionic hydrophilic units in admixture with hydrophobic units. These copolymers have a nonionic character. In order to make them soluble in water, the amount of hydrophilic unit is very high; this limitation does not allow access to a large range of structures. This document also describes block polymers, one block of which is a copolymer comprising acrylic acid units, and another block of which is non-ionic hydrophilic. These block polymers however exhibit a strong fluctuation in their properties as a function of humidity.

The same applies to the block copolymers described in O02 / 28357 which are water-soluble, and in which all the blocks are formed from monomers non-ionic, but which also exhibit large fluctuations in their properties as a function of humidity.

Mention may also be made of application O00 / 71591, which describes block copolymers comprising a cationic homopolymer block associated with a nonionic hydrophilic block, and the use of these copolymers to improve the quality of the foams in personal care products. However, these polymers have the drawback of being not very compatible with anionic compounds, in particular anionic surfactants, generally used in shampoos. Furthermore, when they are used in styling products, for example of the lacquer type, these polymers have the defect of being difficult to remove with shampoo.

Also known from Application O01 / 16187 are diblock or triblock copolymers which can give aqueous gelled compositions; these copolymers can in particular be of the poly (styrene / methacrylic acid) -b-poly (ethyl acrylate / methacrylic acid) type. However, these copolymers are thickeners which, in certain cases, can be considered as a drawback, in particular by making the formulation difficult. Indeed, obtaining gels is not always sought: this is the case for example for aerosols or nail varnishes, for which fluid solutions are necessary. It has therefore been found that the majority of block copolymers intended to be transported in water mainly comprise hydrophobic units and tend to form gels, which is a drawback.

The object of the present invention is to provide block copolymers, or block polymers, which have advantageous mechanical properties, and which can be used in large quantities without appreciably influencing the thickening or gelling, therefore the viscosity, of the composition that contains them. In particular, the copolymers according to the invention do not form, in water, a viscoelastic gel, that is to say a gel having an elastic modulus (G ′) greater than the viscous modulus (G ″). copolymers forming a film or a deposit are also sought, the removal of which with perfect shampooing.

An object of the invention is therefore a linear, ethylenic, block copolymer comprising at least a first block and at least a second block, each block comprising at least one ionic hydrophilic unit, which may be different from a block to l 'other, said ionic hydrophilic unit being present in each sequence at a rate of 2 to 100% by weight relative to the weight of said sequence. Another object is a cosmetic or pharmaceutical composition comprising in a physiologically acceptable medium, in particular cosmetically or dermatologically acceptable, at least one copolymer as defined below.

The copolymers according to the invention have comfortable mechanical properties: they can be rigid while having a certain flexibility or elasticity, ensuring maintenance of the hair lasting over time. They can also have good adhesion without being sticky to the touch. They find a very particular application in the cosmetic field, in particular in hair or make-up. When used in nail polish, these polymers form a deposit that adheres well to the nail without easily wearing out.

The block polymer (or block polymer) according to the invention is a linear block ethylenic polymer, advantageously film-forming.

By "ethylenic" polymer is meant a polymer obtained by polymerization of monomers comprising ethylenic unsaturation.

By "block" polymer is meant a polymer comprising at least 2 successive blocks distinct, that is to say of different chemical natures.

The polymer according to the invention is a polymer with a linear structure. In contrast, a polymer with a non-linear structure is, for example, a polymer with a branched, star, grafted, or other structure. In particular, all the monomers used to prepare a linear polymer are mono-functional, that is to say have only one polymerizable function. As for the polymerization orcers, they can be monofunctional or difunctional.

By “film-forming” polymer is meant a polymer capable of forming on its own or in the presence of an auxiliary film-forming agent, a continuous and adherent film on a support, in particular on keratin materials.

Each block, or block, of the polymer according to the invention is derived from one type of monomer or from several different types of monomer. This means that each block can consist of a homopoly era or a copolymer; this copolymer constituting the sequence which may in turn be statistical or alternating or with a gradient; the distribution of the monomers within each sequence can therefore be random or controlled depending on the nature and / or the reactivity of the monomers and / or the preparation process used. The block polymer according to the invention therefore comprises at least two blocks, advantageously two blocks (diblock) or three blocks (triblock), each of the blocks comprising at least one ionic hydrophilic monomer, present in each block in an amount of at least 2%. by weight relative to the weight of the sequence.

In each sequence, said hydrophilic ionic monomer may in fact be a mixture of different hydrophilic ionic monomers. Furthermore, the ionic hydrophilic monomer (s) may be identical, totally or partially, or different, from one sequence to another.

The ionic hydrophilic monomers are present in each block in an amount of 2 to 100% by weight, relative to the weight of the block, in particular from 3 to 70% by weight, even better from 5 to 50% by weight, or even from 8 to 30% by weight.

A monomer is said to be hydrophilic if the corresponding homopolymer is hydrophilic, that is to say if it is water-soluble or water-dispersible. The omopolymer is water-soluble if it is soluble in water, at a rate of at least 5% by weight, at 25 ° C. The omopolymer is water dispersible if it forms in water, at a concentration of 5% by weight, at 25 ° C, a stable suspension or dispersion of fines. particles, generally spherical. The average size of the particles constituting said dispersion is less than 1 μm and, more generally, varies between 5 and 400 nm, preferably from 10 to 250 nm. These particle sizes are measured by light scattering (with a Coulter Counter type device).

The hydrophilicity of a monomer can also be defined by the value of the logarithm of the apparent partition coefficient octanol-1 / water, also called log P; a monomer can be considered to be hydrophilic when this value is less than or equal to 2, for example between -8 and 2, preferably less than or equal to 1.5, in particular less than or equal to 1, and in particular between -7 and 1, or even between -6 and 0. The log P values are known and are determined according to a standard test which determines the concentration of the monomer in octanol and water. The values can in particular be calculated using the ACD software (Advanced Chemistry Development) Software solaris V4.67; they can also be obtained from Exploring QSAR: hydrophobic, electronic and steric constants (ACS professional reference book, 1995). There is still a website which provides estimated values (address: http: //esc.syrres .com / interkow / kowdemo.htm).

As specified above, the final polymer comprises in each of its sequences at least one hydrophilic monomer present at least 2% by weight relative to the weight of the block.

To do this, it is possible to use as starting monomer ionic hydrophilic monomers as described below, which will be copolymerized according to the state of the art so as to obtain the desired polymer.

However, it is also possible to modify the polymer previously synthesized, so as to obtain said hydrophilic monomers. For example, it is possible to hydrolyze the polymer when it comprises units of the (meth) acrylic ester type, capable of being hydrolyzed to give units having a carboxylic acid function; this may be the case when the polymer comprises units of the (meth) acrylate type of methyl, ethyl, hydroxyethyl, tert-butyl, benzyl, trimethoxysilyl or ethyltrimethσxysilyl. Hydrolysis can thus be carried out once the polymer has been synthesized, under acidic conditions (for example in the presence of sulfuric acid, hydrochloric acid or trifluoroacetic acid) or basic conditions (for example in the presence of hydroxides of alkaline earth metals such as soda or potash, alkali metal alcoholates such as potassium t-butoxide, or amines such as ammonia). The hydrolysis generally takes place between 5 and 100 ° C, preferably between 15 and 80 ° C. The hydrolyzed polymer can then be purified by repeated precipitation. It can also be envisaged to react a compound of the HO-RX, NHR'-RX, HO-RY or NHR'-RY type (X and Y having the meanings given below), with an already formed polymer comprising units of the glycidyl or azlactone type.

The ionic hydrophilic monomers present in the final polymer can be chosen from anionic, cationic and / or amphoteric hydrophilic monomers. Preferably, each of the blocks comprises at least one anionic hydrophilic monomer and / or at least one cationic hydrophilic monomer. In a particular embodiment, at least one block can comprise both at least one cationic hydrophilic monomer and at least one anionic hydrophilic monomer.

Among the anionic hydrophilic monomers, mention may in particular be made of ethylenically unsaturated monomers comprising, for example, at least one carboxylic acid (COOH), phosphonic (P0 ₃ H ₂ ) or sulfonic (S0 ₃ H) function, such as by example those of formula (I) below:

in which : - Ri is a hydrogen atom or a hydrocarbon radical, linear or branched, of type C _p H ₂ p ₊ ι, with p being an integer between 1 and 12, inclusive; In particular, RI can represent a methyl, ethyl, propyl, butyl radical. Preferably, Ri represents hydrogen or a methyl radical.

- Z is a divalent group chosen from -COO-, -CONH-, -CONCH ₃ -, -OCO- or -0-; preferably, Z is chosen from -COO- and -CONH-. - x is 0 or 1, preferably 1. -m is 0 or 1; - R2 is a divalent carbon radical, saturated or unsaturated, optionally aromatic, linear, branched or cyclic, from 1 to 30 carbon atoms, which can comprise 1 to 30 heteroatoms chosen from 0, N, S, and P; In the radical R2, the heteroatom (s), when they are present, may be intercalated in the chain of said radical R2, or else said radical R2 may be substituted by one or more groups comprising them such as hydroxy or amino (NH2, NHR ' or NR'R "with R 'and R" identical or different representing a linear or branched C1-C22 alkyl, in particular methyl or ethyl). In particular R2 may be: - an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, tertiobutylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene, n-tetradecylene, n-docosanylene; - a phenylene radical -C ₆ H ₄ - (ortho, meta or para) optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from 0, N, S, and P; or a benzylene radical -C6H4-CH2- optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from 0, N, S, and P; - a radical of formula -CH ₂ -CHOH-, -CH ₂ - CH2-CHOH-, -CH ₂ -CH ₂ -CH (NH ₂ ) -, -CH ₂ -CH (NH ₂ ) ~, -CH ₂ - CH ₂ - CH (NHR ') -, -CH ₂ -CH (NHR') -, -CH ₂ -CH ₂ -CH (NR'R ") -, -CH ₂ - CH (NR'R") -, -CH ₂ -CH = CH- with R 'and R "representing a linear or branched C1-C18 alkyl, in particular methyl or ethyl.

- Y is a group chosen from -C00H, - SO3H, -OSO3H, -PO (OH) ₂ and -0P0 (0H) ₂ .

Among the more particularly preferred anionic hydrophilic monomers, mention may in particular be made of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, diacrylic acid, dimethyl fumaric acid, citraconic acid, acrylamidopropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonic acid, vinylbenzoic acid, vinylphosphoric acid, vinylsulfonic acid, vinylbenzene sulfonic acid, acrylamidoglycolic acid of formula CH2 = CH-C0NHCH (0H) C00H, vinylphosphonic acid; 2-carboxyethyl (meth) acrylate, sulfopropyl methacrylate or acrylate (CH ₂ = C (CH ₃ ) C0 ₂ (CH ₂ ) ₃ S0 ₃ H), methacrylate or sulfoethyl acrylate and vinyl methyl sulfone, 2-

(methacryloyloxy) ethylphosphate of formula CH ₂ = C (CH ₃ ) C00C ₂ H ₄ 0P (0) (OH) ₂ ; the diallyl randomate of formula C3H ₅ -Cθ2-CH = CH-Cθ2-C ₃ H5; carboxylic anhydrides carrying a vinyl bond such as maleic anhydride, as well as their salts; and their mixtures.

The neutralization of the anionic groups can be carried out by a mineral base, such as LiOH, NaOH, KOH, Ca (OH) ₂ , NH ₄ OH or Zn (OH) 2; or with an organic base such as a primary, secondary or tertiary alkylamine, in particular triethylamine or butylamine. This primary, secondary or tertiary alkylamine can comprise one or more nitrogen and / or oxygen atoms and can therefore comprise, for example, one or more alcohol functions; mention may in particular be made of amino-2-methyl-2-propanol, triethanolamine and dimethylamino2-propanol. Mention may also be made of lysine or 3- (dimethylamino) propylamine.

Among the cationic hydrophilic monomers, mention may be made of ethylenically unsaturated monomers comprising at least one primary, secondary or tertiary amine function, in particular those of formula (II) below:

in which: - RI, Z, x, R2 and m have the same meanings as in formula (I) above;

- X is (a) a group of formula -N-RgR with R6 and R7 representing, independently of one another, (i) a hydrogen atom, (ii) a linear, branched or cyclic alkyl group, saturated or unsaturated, optionally aromatic, comprising from 1 to 30 carbon atoms, possibly comprising 1 to 10 heteroatoms chosen from 0, N, S, and P; in particular a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, lauryl, stearyl group; (iii) an alkylene oxide group of formula - (R80) _y R9 with R8 representing a linear or branched C2-C4 alkyl, R9 is hydrogen or a linear or branched C1-C30 alkyl radical and y is between 1 and 250 inclusive; (iv) R6 and R7 can form with the nitrogen atom a saturated or unsaturated, optionally aromatic ring, comprising in total 5, 6, 7 or 8 atoms, and in particular 4, 5 or 6 carbon atoms and / or 2 to 4 heteroatoms chosen from 0, S and N; said ring can also be fused with one or more other cycles, saturated or unsaturated, optionally aromatic, each comprising 5, 6 or 7 atoms, and in particular 4, 5, 6 or 7 carbon atoms and / or 2 to 4 hetero atoms chosen from 0, S and N; or X represents (b) a group -R'6-N-R'7- in which R'6 and R'7 form with the nitrogen atom a cycle, saturated or unsaturated, optionally aromatic, comprising in total 5, 6, 7 or 8 atoms, and in particular 4, 5 or 6 carbon atoms and / or 2 to 4 heteroatoms chosen from 0, S and N; said cycle being able to be fused with one or more other cycles, saturated or unsaturated, optionally aromatic, each comprising 5, 6 or 7 atoms, and in particular 4, 5, 6, 7 or 8 carbon atoms and / or 2 to 4 heteroatoms chosen among 0, S and N.

For example, X can constitute an aromatic ring or not comprising a cationizable tertiary amine group. or can represent an aromatic heterocycle or not, containing a tertiary nitrogen, cationizable. Among the preferred X radicals, mention may be made of pyridine, indolyl, isoindolinyl, imidazolyl, imidazolinyl, piperidinyl, pyrazolynyl, pyrazolynyl, pyrazolyl, quinoline, pyrazolinyl, pyridinyl, piperazinyl, pyrrolidinyl, quinidinyl, thiazolinyl, morpholineid guanid radicals. their mixtures.

Among the preferred cationic hydrophilic monomers, mention may be made, alone or as a mixture: - 2-vinylpyridine, 4-vinylpyridine, 1 allylamine and 1 allylpyridine; - aminoalkyl (meth) acrylates, such as [N, N-di (C1-C4) (meth) acrylates alkylamino] (C1-C6) alkyl or the (meth) acrylates of [N- (C1-C4) alkylamino] (C1-C6) alkyl and in particular the (meth) acrylate of N, N-dimethylaminoethyl, the (meth) acrylate N, N ~ diethylaminoethyl, 2-aminoethyl (meth) acrylate, 2- (N-tertbutylamino) ethyl (meth) acrylate; - aminoalkyl (meth) acrylamides, such as the (meth) acrylamides of [N, N-di (Cl- C4) alkylamino] (C1-C6) alkyl or the (meth) acrylamides of [N- (C1- C4) alkyl a ino] (C1-C6) alkyl, and in particular the (meth) acryla ide of N, N-dimethylaminoρropyle, the (meth) acrylamide of N, N-dimethylaminoethyl; 3-aminopropyl (meth) acrylamide; - vinylamine, vinylimidazole, 2- (diethylamino) ethylstyrene; - N-vinylimidazole, N-vinyl-2-methylimidazole, N-vinylcarbazole; as well as their salts and / or their quaternized forms.

Among the salified forms, mention may be made of the salts of mineral acids, such as sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, boric acid. Mention may also be made of the salts of organic acids, which may contain one or more carboxylic, sulphonic or phosphonic acid groups. They can be linear, branched or cyclic aliphatic acids or even aromatic acids. These acids may also contain one or more heteroatoms chosen from 0 and N, for example in the form of hydroxyl groups. Mention may in particular be made of propionic acid, acetic acid, terephthalic acid, citric acid and tartaric acid.

The neutralization of the anionic or cationic units, as well as the quaternization, can be total or partial.

The tertiary amino groups can be quaternized by mobile halogen compounds, in particular alkyl halides such as chlorides or C1-C12 alkyl bromides, and for example methyl bromide or ethyl chloride. These groups can also be quaternized by mobile halogen compounds comprising carboxylic or sulphonic acid functions, in particular sodium chloroacetate; or by cyclic sulfones, for example propanesulfone. Amphoteric hydrophilic monomers (or betaines, having at least one charge (+) and at least one charge (-) carried by the same monomer) are thus obtained.

The quaternization can be carried out on the polymer already synthesized or on the starting monomers, before polymerization.

The resulting polymers may therefore comprise amphoteric monomers which may correspond to formula (III) in which :

- Ri, Z, x, R2 and m have the same meanings as in formula (I) above;

- X ' ⁺ is a divalent group of formula - N ⁺ R' ₆ R '7 with R'6 and R'7 representing, independently of one another, (i) a hydrogen atom, (ii) a linear, branched or cyclic, optionally aromatic, alkyl group comprising from 1 to 30 carbon atoms, which may comprise 1 to 8 heteroatoms chosen from 0, N, S and P; for example methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl or isobutyl; (iii) an alkylene oxide group of formula - (R80) _y R9 with R8 representing a linear or branched C2-C4 alkyl, R9 is hydrogen or a linear or branched C1-C30 alkyl radical and y is between 1 and 250 inclusive; (iv) R'6 and R'7 can form a saturated or unsaturated, optionally aromatic, optionally aromatic, ring (NR '6R' 7 or R'6NR'7) with the nitrogen atom, comprising in total 5, 6, 7 or 8 atoms, and in particular 4, 5, 6 or 7 carbon atoms and / or 2 to 4 hetero atoms chosen from 0, S and N; said cycle being able to be merged with one or more other cycles, saturated or unsaturated, optionally aromatic, each comprising 5, 6, 7 or 8 atoms, and in particular 4, 5, 6 or 7 carbon atoms and / or 2 to 4 heteroatoms chosen from 0, S and N.

- Y ^'~ is a group selected from ^-COO, -S0 ₃ ^~, -OS0 ₃ ^", -PO3 ^2" and -PO4 ^2-.

- R3 is a divalent carbon radical, saturated or unsaturated, optionally aromatic, linear, branched or cyclic, from 1 to 30 carbon atoms, possibly comprising 1 to 18 heteroatoms chosen from 0, N, S and. In the radical R3, the heteroatom or atoms, when they are present, may be intercalated in the chain of said radical R3, or else said radical R3 may be substituted by one or more groups comprising them such as hydroxy or amino; in particular R3 can be: - an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, tertiobutylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene, n-tetradecylene, n-docosanylene; - a phenylene radical -C ₆ H ₄ - (ortho, meta or para) optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 5 heteroatoms chosen from 0, N, S, F, Si and P; or a benzylene radical -C ₅ H ₄ -CH ₂ - optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 5 heteroatoms chosen from 0, N, S and P; - n is 0 or 1.

Mention may in particular be made of N, N- dimethyl-N- (2-methacryloyloxyethyl) -N- (3-sulfopropyl) ammonium betaine, N, -dimethyl-N- (3-methacrylamidopropyl) -N- (3-sulfopropyl ) ammonium betaine and 1- (3-sulfopropyl) -2-vinylpyridinium betaine, and mixtures thereof.

In a preferred embodiment, the copolymer according to the invention comprises from 4 to 100% by weight, in particular from 8 to 80% by weight, or even from 10 to 30% by weight, relative to the total weight of the copolymer, of units hydrophilic ionic. Advantageously, the copolymer according to the invention is soluble or dispersible in water, at 25 ° C, in an amount of 5% by weight.

In addition to the hydrophilic ionic monomers, the blocks of the block copolymer according to the invention may comprise one or more additional monomers chosen from non-ionic hydrophilic monomers, hydrophobic monomers and their mixtures.

These additional monomers can be identical or different from one block to another. This or these additional monomers are ethylenic monomers copolymerizable with the hydrophilic ionic monomer (s), whatever their coefficient of reactivity. Preferably, the nonionic hydrophilic monomers may be present in a proportion of 0 to 98% by weight, relative to the weight of the block, in particular from 2 to 95% by weight, and even better still from 3 to 92% by weight, in at least one sequence, even in each sequence.

Preferably, the hydrophobic monomers may be present in a proportion of 0 to 98% by weight, relative to the weight of the block, in particular from 2 to 95% by weight, and even better still from 3 to 92% by weight, in at least a sequence, even in each sequence.

Among the nonionic or hydrophobic hydrophilic monomers capable of being copolymerized with the ionic hydrophilic monomers to form the polymers according to the invention, there may be mentioned, alone or as a mixture,:

- (i) ethylene hydrocarbons having 2 to 10 carbons, such as ethylene, isoprene, or butadiene;

- (ii) the (meth) acrylates of formula:

in which R ₂ is hydrogen or methyl (CH ₃ ) and R ₃ represents: - a linear or branched alkyl group, from 1 to 30 carbon atoms, in which there are (are) optionally intercalated one or more heteroatoms chosen from 0, N, S and P; said alkyl group possibly also being optionally substituted by one or more substituents chosen from OH, halogen atoms (Cl, Br, I and F), and the groups - Si (R ₄ R ₅ R _S ) and - If (R ₄ R ₅ ) 0, in which R ₄ , Rs and R ₆ , which are identical or different, represent a hydrogen atom, a C1-C6 alkyl group or a phenyl group; in particular R ₃ may be a methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, hexyl, ethylhexyl group, in particular ethyl-2-hexyl, octyl, lauryl, isooctyl, isodecyl, dodecyl, cyclohexyl, t-butylcyclohexyl or stearyl; ethyl-2-perfluorohexyl, ethyl-2-perfluorooctyl; or a C1-C4 hydroxyalkyl group such as 2-hydroxyethyl, 2-hydroxybutyl and 2-hydroxypropyl; or an alkoxy group (C _1-4) alkyl (Cι-) as methoxyethyl, ethoxyethyl and methoxypropyl, - cycloalkyl, C ₃ Cχ _2, such as an isobornyl group, - an aryl group of C ₃ to C ₂ o such as the phenyl group, - a C4-C30 aralkyl group (C1-C6 alkyl group) such as 2-phenyl-ethyl, t-butylbenzyl or benzyl, - a 4 to 12-membered heterocyclic group containing one or several heteroatoms chosen from 0, N, and S, the cycle being aromatic or not, a heterocycloalkyl group (alkyl of 1 to 4 C), such as furfurylmethyl or tetrahydrofurfurylmethyl, said cycloalkyl, aryl, aralkyl, heterocyclic or heterocycloalkyl groups which may be optionally substituted by one or more substituents chosen from hydroxyl groups, halogen atoms , and linear or branched C1-4 alkyl groups in which there are optionally intercalated one or more heteroatoms chosen from 0, N, S and P, said alkyl groups being able, in addition, to be optionally substituted with one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and the groups -Si (R4R5R6) and -Si (RRs) 0, in which R ₄ , R ₅ and R _6, identical or different, represent a hydrogen atom, an alkyl group -C ₆ or a phenyl group, - a group - (0C ₂ H _{4) m} -0R '', with m = 5 to 300 and R "= H or C to C30 alkyl, for example - (0C ₂ H ₄ ) _m - OH, - (OC ₂ H ₄ ) _m -0-methyl or - (OC ₂ H ₄ ) _m -0-behenyl; a group - (0C ₃ H ₆ ) _m -0R ", with m = 5 to 300 and R" = H or C _α to C ₃₀ alkyl, for example - (0C ₃ H _s ) _m -0H; or a statistical mixture or block of groups (0C ₂ H ₄ ) _m and (OC ₃ H ₅ ) _m .

- (iii) (meth) acrylamides of formula:

wherein Rs denotes H or methyl; and R ₇ and R _6, identical or different, represent: - a hydrogen atom; or - a linear or branched alkyl group of 1 to 30 carbon atoms, in which there are optionally intercalated one or more heteroatoms chosen from 0, N, S and P; the said alkyl group possibly also being optionally substituted by one or more substituents chosen from -OH, the halogen atoms (Cl, Br, I and F), and the groups -Si (R4R5R6) and -Si (R ₄ R ₅ ) 0, in which R ₄ , R 5 and R ₆ represent a hydrogen atom, a C 1 -C 6 alkyl group or a phenyl group; in particular R6 or R7 may be a methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, hexyl, ethylhexyl, octyl, lauryl, isooctyl, isodecyl, dodecyl, cyclohexyl, t-butylcyclohexyl or stearyl group; ethyl-2-perfluorohexyl, ethyl-2-perfluorooctyl; or a Cι-- ₄ hydroxyalkyl group such as 2-hydroxyethyl, 2-hydroxybutyl and 2-hydroxypropyl; or a (C ₁ -C 4) alkoxy (C _{1 -} 4) alkyl group such as methoxyethyl, ethoxyethyl and methoxypropyl, - a C ₃ to C ₁₂ cycloalkyl group, such as the isobornyl group, - a C to C ₂₀ aryl group such as the phenyl group, a C ₄ to C ₃₀ aralkyl group (C ₁ to C ₅ alkyl group) such as 2-phenyl-ethyl, t-butylbenzyl or benzyl, - a 4 to 12-membered heterocyclic group containing one or more heteroatoms chosen from 0, N, and S, the ring being aromatic or not, - a heterocycloalkyl group (C1-C4 alkyl), such as furfurylmethyl or tetrahydrofurfurylmethyl, said groups cycloalkyl, aryl, aralkyl, heterocyclic or heterocycloalkyl which may be optionally substituted by one or more substituents chosen from hydroxyl groups, halogen atoms, and C 1-4 alkyl groups, linear or branched in which is optionally present intercalated one or more heteroatoms chosen from 0, N, S and P, said alkyl groups being able, in addition, to be optionally substituted by one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and the groups -Si (R4R ₅ R ₆ ) and -Si (R ₄ R ₅ ) 0, in which R ₄ , R ₅ and R ₆ , identical or different, represent a hydrogen atom, a group C1 alkyl C ₆ or phenyl; - a group - (OC ₂ H _{4) m} -OR '', with m = 5 to 300 and R "= H or alkyl of Ci to C _30, for example - (0C ₂ H _{4) m} - OH, - ( OC ₂ H ₄ ) _m -0-methyl or - (OC ₂ H ₄ ) _m -0-behenyl; a group - (OC ₃ H ₅ ) _m -0R '', with m = 5 to 300 and R "= H or alkyl from _x to C ₃₀ , for example - (OC3H ₆ ) _m ^_ OH; or a statistical mixture or block of groups (OC ₂ H4) - and (OC3H6) m-

Examples of such additional monomers are (meth) acrylamide, N-ethyl (meth) acrylamide, N-butylacrylamide, Nt-butylacrylamide, N-isopropylacrylamide, N, N-dimethyl (meth) acrylamide, N, N-dibutylacrylamide, N-octylacrylamide, N-dodecylacrylamide, N-undecylacrylamide, and N- (2-hydroxypropylmethacrylamide).

- (iv) vinyl compounds of formula: CH ₂ ⁼ CH — Rg, in which R9 is a hydroxyl group; halogen (Cl or F); an NH ₂ group; a group -OR10 where Rio represents a phenyl group or an alkyl group at C ₁₂ (the monomer is a vinyl or allylic ether); an acetamide group (NHCOCH3); an OCORn group where Ru represents a linear or branched alkyl group of 2 to 12 carbons (the monomer is a vinyl or allyl ester), C3-C12 cycloalkyl, C3-C20 aryl or C4-C30 arallyl; or alternatively R ₉ is chosen from: - a linear or branched alkyl group, comprising 1 to 30 carbon atoms, in which there are (are) optionally intercalated one or more heteroatoms chosen from O, N, S and P; said alkyl group possibly also being optionally substituted by one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and groups -Si (R ₄ R ₅ R ₆ ) and -Si (R ₄ R ₅ ) 0, in which R ₄ , R ₅ and R ₆ , identical or different, represent a hydrogen atom, a C1-C6 alkyl group or a phenyl group; a C ₃ to C ₁₂ cycloalkyl group such as isobornyl, cyclohexane, - a C ₃ to C ₂ o aryl group such as phenyl, - a C ₄ to C 30 arylealkyl or alkylaryl group (C ₁ to C ₅ alkyl group) such as 2-phenylethyl or benzyl, - a heterocyclic group from 4 to 12 links containing one or more heteroatoms chosen from 0, N, and S, the ring being aromatic or not, such as N-vinylpyrrolidone and N-vinylcaprolactam; a heterocycloalkyl group (alkyl of 1 to 4 C), such as furfurylmethyl or tetrahydrofurfurylmethyl, said cycloalkyl, aryl, aralkyl, heterocyclic or heterocycloalkyl groups which may be optionally substituted by one or more substituents chosen from hydroxyl groups, halogen atoms , and alkyl groups of 1 to 4 C linear or branched in which there are (are) optionally intercalated (s) one or more heteroatoms chosen from 0, N, S and P, said alkyl groups being able, in addition, to be optionally substituted with one or more substituents chosen from -OH, the halogen atoms (Cl, Br, I and F) and the groups -Si (R ₄ R ₅ Rs) and -Si (R ₄ R ₅ ) 0, in which R _4, R ₅ and Rβ, identical or different, represent a hydrogen atom, an alkyl group -C ₆ or phenyl.

Examples of such additional monomers are vinylcyclohexane, and styrene (hydrophobic); N-vinylpyrrolidone and N-vinylcaprolactam (non-ionic hydrophiles); vinyl acetate, vinyl propionate, vinyl butyrate, vinyl ethylhexanoate, vinyl neononanoate and vinyl neododecanoate (hydrophobic); vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether.

- (v) the allylic compounds of formula: CH ₂ = CH-CH ₂ -R ₉ or CH ₂ = C (CH ₃ ) -CH ₂ -R ₉ in which R9 has the same meaning as above. Mention may in particular be made of allylmethylether, 3-allyloxy-1,2-propanediol (CH ₂ = CHCH ₂ 0CH ₂ CH- (0H) CH ₂ 0H) and 2-allyloxyethanol (CH ₂ = CHCH ₂ OC ₂ H ₄ OH) .

- (vi) (meth) acrylic, (meth) acrylamides or silicone vinyl monomers, such as methacryloxypropyltris (trimethylsiloxy) silane or acryloxypropylpoly-dimethylsiloxane, or silicone (meth) acrylamides.

Among the more particularly preferred additional monomers (in particular nonionic hydrophilic), there may be mentioned, alone or as a mixture, the following monomers for which the Tg is given in parenthesis for information: - (meth) acrylates and (meth) acrylamides of hydroxyalkyl in which the alkyl group contains 2 to 4 carbon atoms, in particular 2-hydroxyethyl acrylate (Tg ≈ 15 ° C), 2-hydroxyethyl methacrylate (55 ° C), methacrylate of 2-hydroxyρropyle, 4-hydroxybutyl methacrylate, N- (2-hydroxypropyl) (meth) acrylamide; - (meth) acrylates and (meth) acrylamides of alkoxy (Cι_ ₄ ) alkyl (Cι- ₄ ) such as (meth) acrylates and (meth) acrylamides of methoxyethyl, 2-ethoxyethyl, methoxypropyl and di- (2-ethoxyethyl); more particularly 2-ethoxyethyl methacrylate; - (meth) acrylamide and N, N-dimethylacrylamide; - (meth) acrylates and (meth) acrylamides group - (OC ₂ H 4) _m -OR '', where m - 5 to 300 and R "= H or alkyl of Ci to C _4, for example ( meth) acrylates and polyethylene glycol (meth) acrylamides (methoxy or hydroxy terminated); and more particularly hydroxy terminated polyethylene glycol methacrylate (n = 8, 10, 12, 45, 90 or 200) and polyethylene glycol methacrylate methoxy termination (n = 8, 10, 12, 45, 90 or 200) (Tg = -55 ° C) - vinyllactams such as vinylpyrrolidone and vinylcaprolacta e; - vinyl ethers such as vinyl methyl ether (Tg = -34 ° C) and vinylethyl ether; - vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam; - (meth) acrylates of polysaccharide such as sucrose acrylate and ethyl (meth) acrylate glucoside. Mention may also be made, among the additional monomers (in particular hydrophobic) which are more particularly preferred, alone or as a mixture, the following monomers for which the Tg is given in parenthesis as an indication: - t-butylbenzyl acrylate, t-butylcyclohexyl, isobornyl acrylate (94 ° C), furfuryl acrylate, n-hexyl acrylate (45 ° C), t-butyl acrylate (50 ° C), cyclohexyl acrylate (19 ° C), hydroxyethyl acrylate (15 ° C), methyl acrylate (10 ° C), ethyl acrylate (- 24 ° C), acrylate isobutyl (-24 ° C), methoxyethyl acrylate (-33 ° C), n-butyl acrylate (-54 ° C), ethylhexyl acrylate (-50 ° C), acrylate hexyl, octyl acrylate, lauryl acrylate, isooctyl acrylate, isodecyl acrylate; - t-butylbenzyl methacrylate, t-butylcyclohexyl methacrylate, isobornyl methacrylate (111 ° C), methyl methacrylate (100 ° C), cyclohexyl methacrylate (83 ° C), methacrylate ethyl (65 ° C), benzyl methacrylate (54 ° C), isobutyl methacrylate (53 ° C), butyl methacrylate (20 ° C), n-hexyl methacrylate (-5 ° C) , ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, isooctyl methacrylate, isodecyl methacrylate; - styrene (100 ° C), vinylcyclohexane, vinyl acetate (23 ° C), vinyl methyl ether (- 34 ° C), vinyl neononanoate, vinyl neododecanoate; - N-butylacrylamide,

N-isopropylacrylamide, N, N-dimethylacrylamide,

N, N-dibutylacrylamide, N-t-butylacrylamide, N-octylacrylamide.

Preferably, the copolymers according to the invention can comprise at least one block comprising monomers chosen from isobornyl acrylate, cyclohexyl acrylate (19 ° C), ethyl acrylate (10 ° C), methyl methacrylate (100 ° C), cyclohexyl methacrylate (83 ° C), ethyl methacrylate (65 ° C), butyl methacrylate (20 ° C) and styrene (100 ° C).

Preferably, the copolymers according to the invention can comprise at least one block comprising monomers chosen from n-hexyl methacrylate (-5 ° C), ethyl acrylate (-24 ° C), acrylate d isobutyl (-2 ° C), n-butyl acrylate (-54 ° C), ethylhexyl acrylate (-50 ° C); methoxy poly (ethylene glycol) mono methacrylate with a number m of ethlene glycol units of 8.12, 90, 180, 200; methoxy poly (ethylene glycol) mono methacrylamide with m = 8.12, 90, 180 or 200; poly (ethylene glycol) OH (meth) acrylate with m = 8.12, 90, 180 or 200; poly (ethylene glycol) OH (meth) acrylamide with m = 8.12, 90, 180 or 200; vinylpyrrolidone, vinylcaprolactam; vinyl methyl ether and vinyl ethyl ether. Preferably, the copolymers according to the invention can be copolymers comprising two blocks (diblocks), such as: - poly (acrylic acid-butyl co-acrylate) -b-poly (methyl methacrylate-co-acrylic acid) , and - poly (methacrylic acid-butyl co-acrylate) -b-poly (methyl methacrylate-co-methacrylic acid).

Preferably, the copolymers according to the invention can be copolymers comprising three blocks (triblocks), such as: - poly (methyl methacrylate co acrylic acid) -b-poly (acrylic acid butyl acrylate) -b-poly (methyl methacrylate co acrylic acid), - poly (methyl methacrylate co (meth) acrylic acid) -b-poly (methacrylic acid co butyl acrylate) -b-poly (methyl methacrylate co methacrylic acid), - poly (methyl acrylate co acrylic acid) -b-poly (acrylic acid co butyl acrylate) -b-poly (methyl acrylate co acrylic acid), - poly (acrylic acid co butyl acrylate) -b-poly ( methyl methacrylate co acrylic acid) -b-poly (acrylic acid co butyl acrylate); - (acrylic polyacid) -b-poly (acrylic acid butyl acrylate) -b- (poly acrylic acid); - (methacrylic polyacid) -b-poly (methacrylic acid butyl acrylate) -b- (poly methacrylic acid); - poly (acrylic acid co cyclohexyl acrylate) -b-poly (acrylic acid co butyl acrylate) -b- pol (acrylic acid co cyclohexyl acrylate; - poly (acrylic acid co butyl acrylate) -b-poly (acrylic acid co cyclohexyl acrylate-b-poly (acrylic acid co butyl acrylate); - poly (acrylic acid co cyclohexyl methacrylate) -b-poly (acrylic acid co butyl acrylate) -b-poly (acrylic acid co cyclohexyl methacrylate; - poly (acrylic acid co isobornyl acrylate) -b-poly (acrylic acid co butyl acrylate) -b-pol (acrylic acid co isobornyl acrylate); - poly (methyl methacrylate co acrylic acid) -b-poly (acrylic acid co methoxypol (ethylene glycol) mono methacrylate with m = 12) -b-poly (methyl methacrylate co acrylic acid); - poly (acrylic acid co methoxy poly (ethylene glycol) mono methacrylate with m = 12) -b- poly (methyl methacrylate co acrylic acid) -b- poly (acrylic acid co methoxy poly (ethylene glycol) mono methacrylate with m = 12). In general, the monomers constituting each block are preferably chosen so as to promote the separation of the phases between said blocks, since this is what will determine the properties of the final polymer.

Preferably, at least one of the blocks of the copolymer according to the invention has a glass transition temperature (Tg) less than or equal to 20 ° C. Also preferably, at least one of the blocks of the copolymer according to the invention has a glass transition temperature (Tg) greater than or equal to 20 ° C. The method of measuring Tg is explained before the examples.

In a particular embodiment, the copolymer according to the invention can comprise both a block having a Tg greater than or equal to 20 ° C and a block having a Tg less than 20 ° C. The copolymer obtained has a so-called "elastomeric" character. It may be a diblock copolymer, comprising only these two blocks or a triblock copolymer or comprising three distinct blocks, for example a central block of Tg below 20 ° C and two blocks at the ends of Tg higher or equal to 20 ° C; or a central sequence of Tg greater than or equal to 20 ° C and two sequences at the ends of Tg less than or equal to 20 ° C. In another embodiment of the invention, the copolymer can comprise at least two distinct blocks, both having a Tg greater than or equal to 20 ° C. Said block copolymer then has a so-called "rigid" character.

Tg sequences greater than 20 ° C can be obtained by homopoly erization of monomers whose homopolymers have a Tg> 20 ° C or by copolymerization of monomers of Tg> 20 ° C, but also by copolymerization of monomers of Tg> 20 ° C to which monomers of Tg <20 ° C can be added.

Likewise, Tg sequences below 20 ° C can be obtained by homopolymerization of monomers of Tg <20 ° C or copolymerization of monomers of Tg <20 ° C, but also by copolymerization of monomers of Tg <20 ° C to which one can add monomers of Tg> 20 ° C.

In another embodiment, the total content of the copolymer in monomers, the homopolymer of which has a Tg greater than 20 ° C., is preferably greater than or equal to 50% by weight, in particular of the order of 70% to 100% by weight, relative to the total weight of the block copolymer. Said block copolymer then also has a so-called "rigid" character. In another embodiment of the invention, the copolymer can comprise at least two distinct blocks, both having a Tg less than or equal to 20 ° C. Said block copolymer then has a so-called "adhesive" character.

In another embodiment, the total content of the copolymer in monomers, the homopolymer of which has a Tg of less than 20 ° C., is preferably greater than or equal to 60% by weight, in particular of the order of 70% to 100% by weight, relative to the total weight of the block copolymer. Said block copolymer then has a so-called "adhesive" character.

Furthermore, in a particular embodiment, the copolymer according to the invention comprises at least one hydrophilic block which has a Tg greater than or equal to 0 ° C, for example between 0 and 250 ° C, in particular between 50 ° C and 200 ° C.

The weight average molecular weight Mw of the block copolymer according to the invention is preferably between 4,000 and 1,000,000, preferably between 10,000 and 800,000, more preferably between 20,000 and 500,000, especially between 60,000 and 350,000.

Advantageously, the weight-average molecular mass Mw of each block or sequence is between 2000 and 500,000, preferably between 5,000 and 400,000, and better between 10,000 and 300,000.

The polymers according to the invention can be diblock polymers of type AB; or alternatively triblock polymers of the ABA, BAB, ABC type with C different from A and B; or also multiblock polymers having more than three blocks, for example of the type (AB) n, (ABA) n, (BAB) n, (ABC) n, ABCD, with A, B, C and D of different chemical nature. Preferably, the polymer according to the invention comprises at least 3 successive blocks, two successive blocks being different: for example of the ABA or ABC type.

Said polymers can be prepared according to methods known to those skilled in the art. Among these methods, mention may be made of anionic polymerization; controlled radical polymerization, for example with xanthans, dithiocarbamates or dithioesters; polymerization using nitroxide type precursors; radical atom transfer polymerization (ATRP); group transfer polymerization. For example, the block copolymers according to the invention can be obtained by living or pseudo-living radical polymerization known as still controlled, described in particular in "New Method of Polymer Synthesis", Blackie Académie & Professional, Londres, 1995, volume 2, page 1. Controlled radical polymerization designates polymerizations for which the secondary reactions which usually lead to the disappearance of the propagating species (termination reaction or transfer) are made very unlikely compared to the propagation reaction thanks to a free radical control agent. The imperfection of this mode of polymerization lies in the fact that when the concentrations of free radicals become high relative to the concentration of monomer, the secondary reactions become decisive again and tend to widen the distribution of the masses For the record, we recall that the polymerization living or pseudo-living is a polymerization for which the growth of polymer chains ceases only with the disappearance of the monomer. The number average mass (Mn) increases with the conversion. Such polymerizations lead to copolymers whose mass dispersity is low, that is to say to polymers with a polydispersity index by mass (Ip) generally less than 2. Anionic polymerization is a typical example of living polymerization. Pseudo-living polymerization is, in turn, associated with controlled radical polymerization. Among the main types of controlled radical polymerization, mention may be made of: - radical polymerization controlled by nitroxides. We can in particular refer to patent applications O96 / 24620 and WO00 / 71501 which describe the tools of this polymerization and their implementation, as well as the articles published by Fischer (Chemical Reviews, 2001, 101, 3581), by Tordo and Gnanou (J. Am. Che. Soc. 2000, 122, 5929) and Hawker (J. Am. Chem. Soc. 1999, 121, 3904); - polymerization by radical atom transfer, in particular described in application O96 / 30421 and which proceeds by reversible insertion on an organometallic complex in a carbon-halogen type bond; - radical polymerization controlled by sulfur derivatives of xanthate type, dithioesters, trithiocarbonates or carbamates, as described in applications FR2821620, O98 / 01478, 099/35177, 098/58974, W099 / 31144, WO97 / 01478 and in the publication from Rizzardo & al. (Macromolecules, 1998, 31, 5559). Thanks to these modes of polymerization, the polymer chains of the copolymers grow simultaneously and therefore incorporate at all times the same ratio of co-monomers. All the chains therefore have the same or similar structures, hence a low dispersity in composition. These chains also have a low mass polydispersity index. Thus, the polymerization can be carried out according to the atom transfer technique (Atom Transfer Radical Polymerization or "ATRP", in English), or by reaction with a nitroxide, or even according to the technique of "reversible addition- fragmentation chain transfer "(" RAFT ") or finally by the reverse “ATRP” technique, called “reverse ATRP”. The radical polymerization technique by atom transfer consists in blocking the growing radical species in the form of a C-halide bond (in the presence of a metal / ligand complex). This type of polymerization results in a control of the mass of the polymers formed and in a low mass dispersity index. In general, radical polymerization by transfer of atoms is carried out by polymerization of one or more polymerizable monomers by the radical route, in the presence of: - an initiator having at least one transferable halogen atom; - a halogen compound comprising a transition metal capable of participating in a reduction step with the initiator and a “dormant” polymer chain, this will be called “chain transfer agent”; and - a ligand which can be chosen from compounds comprising a nitrogen (N), oxygen (0), phosphorus (P) or sulfur (S) atom, capable of being coordinated by a σ bond to said compound comprising a transition metal, the formation of direct bonds between said compound comprising a transition metal and the polymer being formed being avoided. The halogen atom is preferably a chlorine or bromine atom. This process is in particular described in application WO 97/18247 and in the article by Matyjasezwski et al. published in JACS, 117, page 5614 (1995).

The radical polymerization technique by reaction with a nitroxide consists in blocking the growing radical species in the form of a bond of the C-0-NR _a R type where R _a and Rb can be, independently of one another, a alkyl radical having from 2 to 30 carbon atoms or forming one and the other, with the nitrogen atom, a ring having from 4 to 20 carbon atoms, such as for example a ring 2, 2, 6, 6-tetramethylpiperidinyl. This polymerization technique is described in particular in the articles "Living free radical polymerization: a unique technique for preparation of controlled macromolecular architectures" CJ Hawker; Chem. Res. 1997,30,373-82, and "Macromolecular engineering via living free radical polymerizations" published in Macromol. Chem. Phys. 1998, vol. 199, pages 923 - 935, or even in application OA-99/03894.

The RAFT (reversible addition-fragmentation chain transfer) polymerization technique consists in blocking the growing radical species in the form of a CS-type bond. Dithio compounds such as dithioesters (-C (S) S-), such as dithiobenzoates, dithiocarbamates (-NC (S) S-) or dithiocarbonates (-OC (S) S-) (xanthates) are used for this. ). These compounds make it possible to control the chain growth of a wide range of monomers. However, the dithioesters inhibit the polymerization of vinyl esters, while the dithiocarba ates are very weakly active vis-à-vis methacrylates, which limits to some extent the application of these compounds. This technique is notably described in application OA-98/58974 by RHODIA and in the article "A more versatile route to block copolymers and other polymers of complex architecture by living radical polymerization: the RAFT process", published in Macromolecules, 1999, volume 32, pages 2,071-2,074. The application OA-98/58974 already cited and the application WO-A-99/31144 by CSIRO relate to the use of dithiocarbamates as “RAFT” reagents. vary the ratio of the concentration of monomer to the concentration of chain transfer agent, the molecular weight of the polymer can be modified.

The polymerization generally takes place in several stages according to the following general scheme: - a) in a first stage, the first monomer or mixture of monomers is polymerized to form a macroinitiator or precursor; - b) the polymers can be purified by precipitation and then dried under vacuum, - c) in a second step, the polymerization of the second block consisting of a monomer or a mixture of monomers is carried out at the end of the macroinitiator. Steps b and c are repeated as many times as necessary according to the number of sequences, which is the case for the production of diblock polymers of type AB, triblocks of type ABC or multiblocks (AB) π or (ABC) n with A , B and C of different chemical natures. Usually, to produce symmetrical triblock polymers of ABA or BAB type, a difunctional initiator is generally used. The chain transfer agents and solvents may be the same or different in step a) and step b).

The block or block polymers according to the invention can also be obtained using the conventional radical polymerization technique by carrying out the casting of the monomers in a sequenced manner. In this case, only control of the nature of the sequences is possible (no control of the masses). This involves first polymerizing an Ml monomer in a polymerization reactor; to follow, by kinetics for example, its consumption over time and then when Ml is consumed at around 95%, then to introduce a new monomer M2 into the polymerization reactor. A block structure polymer of the M1-M2 type is thus easily obtained.

The copolymers according to the invention can be present in the compositions according to the invention in an amount of 0.1% to 60% by weight, preferably 0.5% to 50% by weight, in particular 1% to 30% by weight, or even 2% to 20% by weight, relative to the total weight of the composition.

They can be present in the composition in dissolved form, for example in water or an organic solvent, or else in the form of an aqueous or organic dispersion. Preferably, they are in the form of a dispersion of polymer particles in water, said particles possibly having a size of 5 to 400 nm, in particular 10 to 250 nm, measured by light scattering (with a Coulter type device Counter).

One of the characteristics of the copolymers according to the invention is that they do not form a viscoelastic gel, in water at 25 ° C., at a concentration of 5% by weight, in particular at a concentration of 10% by weight, or even of 20% by weight.

In particular, the copolymers according to the invention are such that a solution of these copolymers, at 20% by weight in water, has a viscosity at 25 ° C of between 1 and 10,000 centipoises (or mPa.s), in particular from 2 to 5,000 mPa.s and in particular from 5 to 3,000 mPa.s. The viscosity is measured using a Brookfield viscometer, with a needle-like module (spindle). A person skilled in the art knows how to choose the “speed / time” pair and the needle type mobile from among the needles varying from number 00 to 07, based on their general knowledge, so as to be able to measure low-viscous liquid compounds. Preferably, 35% torque and a 02 needle are used.

The rheological behavior of the copolymers according to the invention can also be illustrated by the value of their elastic (G ¹ ) and viscous (G ") moduli. Thus, a solution at 5% by weight of copolymer in water present, preferably , an elastic modulus lower than the viscous modulus (G '<G "); in particular the elastic module is between 0.1 and 20 Pa, and the viscous module is between 0.1 and 20 Pa. These modules are determined at 25 ° C, at 1 Hz, with a constrained rheometer (HAAKE RS 150) equipped with a sandblasted titanium body fitted with an anti-evaporation device, a planetary measuring body with a diameter of 6 cm and a 2 ° angle. The shear rate or stress frequency is 1 Hz (s ^-1 ).

The cosmetic or pharmaceutical compositions according to the invention comprise, in addition to said polymers, a physiologically acceptable medium, in particular cosmetically or dermatologically acceptable, that is to say a medium compatible with keratin materials such as the skin of the face or body, hair, eyelashes, eyebrows and nails. The composition can thus comprise, a hydrophilic medium comprising water or a mixture of water and organic solvent (s) hydrophilic (s) such as alcohols and in particular linear or branched lower monoalcohols having from 2 to 5 carbon atoms such as ethanol, isopropanol or n-propanol, and polyols such as glycerin, diglycerin, propylene glycol, sorbitol, pentylene glycol, and polyethylene glycols, or even C ethers ₂ and hydrophilic C ₂ -C ₄ aldehydes. The water or the mixture of water and hydrophilic organic solvents may be present in the composition according to the invention in a content ranging from 0.1% to 99% by weight, relative to the total weight of the composition, and preferably 10% to 80% by weight.

The composition may also comprise a fatty phase, in particular consisting of fatty substances liquid at room temperature (25 ° C. in general) and / or fatty substances solid at ambient temperature such as waxes, pasty fatty substances, gums and their mixtures. . These fatty substances can be of animal, vegetable, mineral or synthetic origin. This fatty phase can, in addition, contain lipophilic organic solvents. As fatty substances liquid at room temperature, often called oils, which can be used in the invention, mention may be made of: hydrocarbon oils of animal origin such as perhydrosqualene; vegetable hydrocarbon oils such as liquid triglycerides of fatty acids with 4 to 10 carbon atoms such as the triglycerides of heptanoic or octanoic acids, or even sunflower, corn, soybean, grape seed, sesame, apricot, macadamia oils, castor, avocado, triglycerides of caprylic / capric acids, jojoba oil, shea butter; linear or branched hydrocarbons, of mineral or synthetic origin such as paraffin oils and their derivatives, petrolatum, polydecenes, hydrogenated polyisobutene such as parlameam; synthetic esters and ethers, in particular of fatty acids such as, for example, Purcellin oil, isopropyl myristate, ethyl-2-hexyl palmitate, octyl-2-dodecyl stearate, erucate octyl-2-dodecyl, isostearyl isostearate; hydroxylated esters such as isostearyl lactate, octylhydroxystearate, octyldodecyl hydroxystearate, diisostearylmalate, triisoketyl citrate, heptanoates, octanoates, decanoates of fatty alcohols; polyol esters such as propylene glycol dioctanoate, neopentylglycol diheptanoate, diethylene glycol diisononanoate; and pentaerythritol esters; fatty alcohols having from 12 to 26 carbon atoms such as octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylρentadecanol, oleic alcohol; partially hydrocarbon and / or silicone fluorinated oils; silicone oils such as polymethylsiloxanes (PDMS) volatile or not, linear or cyclic, liquid or pasty to ambient temperature such as cyclomethicones, dimethicones, optionally comprising a phenyl group, such as phenyl trimethicones, phenyltrimethylsiloxydiphenyl siloxanes, diphenylmethyldimethyl-trisiloxanes, diphenyl dimethicones, phenyl dimethicones, polymethylphenyl siloxanes; their mixtures. These oils can be present in a content ranging from 0.01 to 90%, and better still from 0.1 to 85% by weight, relative to the total weight of the composition.

The composition according to the invention can also comprise one or more organic solvents, physiologically acceptable. These solvents can generally be present in a content ranging from 0.1 to 90%, preferably from 0.5 to 85%, more preferably from 10 to 80% by weight, relative to the total weight of the composition, and better still from 30 to 50%. Mention may in particular be made, in addition to the hydrophilic organic solvents mentioned above, ketones which are liquid at room temperature such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone, acetone; propylene glycol ethers which are liquid at room temperature such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol mono n-butyl ether; short chain esters (having from 3 to 8 carbon atoms in total) such as ethyl acetate, methyl acetate, propyl acetate, n-butyl acetate, isopentyl acetate; ethers liquid at 25 ° C such as diethyl ether, dimethyl ether or dichlorodiethyl ether; alkanes liquid at 25 ° C such as decane, heptane, dodecane, isododecane, cyclohexane; aromatic cyclic compounds liquid at 25 ° C such as toluene and xylene; aldehydes liquid at 25 ° C such as benzaldehyde, acetaldehyde and their mixtures.

By wax within the meaning of the present invention is meant a lipophilic compound, solid at room temperature (25 ° C.), with reversible solid / liquid state change, having a melting point greater than or equal to 25 ° C. up to 'at 120 ° C. By bringing the wax to the liquid state (melting), it is possible to make it miscible with the oils which may be present and to form a homogeneous mixture microscopically, but by bringing the temperature of the mixture to room temperature, one recrystallizes the wax in the oils of the mixture. The melting point of the wax can be measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name DSC 30 by the company METLER. The waxes can be hydrocarbon, fluorinated and / or silicone and be of vegetable, mineral, animal and / or synthetic origin. In particular, the waxes have a melting point greater than 30 ° C and better still greater than 45 ° C. As wax which can be used in the composition of the invention, mention may be made of beeswax, Carnauba or Candellila wax, paraffin, microcrystalline waxes, ceresin or ozokerite; synthetic waxes such as polyethylene or Fischer Tropsch waxes, silicone waxes such as alkyl or alkoxy-dimethicone having from 16 to 45 carbon atoms. The gums are generally high molecular weight polydimethylsiloxanes (PDMS) or cellulose gums or polysaccharides and the pasty bodies are generally hydrocarbon compounds such as lanolines and their derivatives or PDMS. The nature and quantity of the solid bodies are a function of the mechanical properties and of the desired textures. As an indication, the composition may contain from 0.1 to 50% by weight of waxes, relative to the total weight of the composition and better still from 1 to 30% by weight.

The composition according to the invention can also comprise, in a particulate phase, pigments and / or nacres and / or fillers usually used in cosmetic compositions. The composition can also comprise other coloring materials chosen from water-soluble dyes or liposoluble dyes well known to those skilled in the art. By pigments, it is necessary to understand particles of any shape, white or colored, mineral or organic, insoluble in the physiological medium, intended to color the composition. By fillers, it is necessary to understand colorless or white, mineral or synthetic particles, lamellar or non-lamellar, intended to give body or rigidity to the composition, and / or softness, mattness and uniformity. makeup. By nacres, it is necessary to understand particles of any iridescent shape, in particular produced by certain molluscs in their shell or else synthesized. The pigments can be present in the composition in an amount of 0.01 to 25% by weight of the final composition, and preferably in an amount of 3 to 10% by weight. They can be white or colored, mineral or organic. Mention may be made of titanium, zirconium or cerium oxides, as well as zinc, iron or chromium oxides, ferric blue, chromium hydrate, carbon black, ultramarines (aluminosilicate polysulphides) , manganese pyrophosphate and certain metallic powders such as those of silver or aluminum. Mention may also be made of the D&C pigments and the lacquers commonly used to give the lips and the skin a makeup effect, which are calcium, barium, aluminum, strontium or zirconium salts. The nacres can be present in the composition in an amount of 0.01 to 20% by weight, preferably at a rate of the order of 3 to 10% by weight. Among the possible mother-of-pearl, we can cite mother-of-pearl natural, mica coated with titanium oxide, iron oxide, natural pigment or bismuth oxychloride as well as colored titanium mica. Among the dyes, liposoluble or water-soluble, which may be present in the composition, alone or as a mixture, at a rate of 0.001 to 15% by weight, preferably 0.01 to 5% by weight and in particular from 0.1 to 2% by weight, relative to the total weight of the composition, there may be mentioned the disodium salt of culvert, the disodium salt of alizarin green, quinoline yellow, the trisodium salt of amaranth, the disodium salt of tartrazine, the salt monosodium rhodamine, disodium fuchsin salt, xanthophyll, methylene blue, cochineal carmine, halo-acid, azo, anthraquinone dyes, copper or iron sulfate, Sudan brown, Sudan red and annatto, as well as beet juice and carotene. The composition according to the invention may also further comprise one or more fillers, in particular in a content ranging from 0.01% to 50% by weight, relative to the total weight of the composition, preferably ranging from 0.02% at 30% by weight. The fillers can be mineral or organic of any shape, platelet, spherical or oblong. Mention may be made of talc, mica, silica, kaolin, polyamide (Nylon®), poly-β-alanine and polyethylene powders, powders of tetrafluoroethylene polymers (Teflon®), lauroyl-lysine, starch, boron nitride, hollow polymeric microspheres such as those of polyvinylidene / acrylonitrile such as Expancel® (Nobel Industrie), acrylic acid copolymers (Polytrap® from Dow Corning) and silicone resin microbeads (Tospearls® from Toshiba, for example), elastomeric polyorganosiloxane particles , precipitated calcium carbonate, magnesium carbonate and hydrocarbon, hydroxyapatite, hollow silica microspheres (Silica Beads® from Maprecos), glass or ceramic microcapsules, metal soaps derived from organic carboxylic acids having from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc, magnesium or lithium stearate, zinc laurate, magnesium myristate.

The composition may further comprise an additional polymer such as a film-forming polymer. According to the present invention, the term "film-forming polymer" means a polymer capable of forming on its own or in the presence of an auxiliary film-forming agent, a continuous and adherent film on a support, in particular on keratin materials. Among the film-forming polymers capable of being used in the composition of the present invention, mention may be made of synthetic polymers, of radical type or of polycondensate type, polymers of natural origin and their mixtures, in particular acrylic polymers, polyurethanes , polyesters, polyamides, polyureas, cellulosic polymers such as nitrocellulose. The composition according to the invention can also comprise ingredients commonly used in cosmetics, such as vitamins, thickeners, gelling agents, trace elements, softeners, sequestering agents, perfumes, alkalizing or acidifying agents, preservatives, sunscreens, surfactants, antioxidants, anti-hair loss agents, dandruff agents, propellants, ceramides, or mixtures thereof. Of course, those skilled in the art will take care to choose this or these optional additional compounds, and / or their quantity, in such a way that the advantageous properties of the composition according to the invention are not, or not substantially, affected by the planned addition.

The composition according to the invention may be in the form of a suspension, a dispersion in particular of oil in water by means of vesicles; an oily solution possibly thickened or even gelled; an oil-in-water, water-in-oil, or multiple emulsion; a gel or foam; an oily or emulsified gel; a dispersion of vesicles, in particular lipid vesicles; a biphasic or multiphase lotion; a spray; loose, compact or poured powder; an anhydrous paste. This composition may have the appearance of a lotion, a cream, an ointment, a flexible paste, an ointment, a cast or molded solid and in particular in stick or in a cup, or alternatively of compacted solid. Those skilled in the art can choose the appropriate dosage form, as well as 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 of the application envisaged for the composition.

The cosmetic composition according to the invention may be in the form of a care and / or make-up product for the skin of the body or the face, the lips and the hair, a sun or self-tanning product, or even a hair product. It finds in particular a particularly interesting application in the field of make-up of the skin, semi-mucous membranes, mucous membranes and / or integuments (nails, eyelashes, eyebrows, hair and hair). It can thus be in the form of a care and / or makeup composition, in particular a product for the complexion such as a foundation, a blusher or an eyeshadow; a lip product such as lipstick or lip care; a concealer; a blush, a mascara, an eyeliner; an eyebrow makeup product, a lip or eye pencil; a nail product such as nail polish or nail care; a body makeup product; a hair makeup product (mascara or hair spray). The composition according to the invention may be a composition for protecting or caring for the skin of the face, neck, hands or body, in particular an anti-wrinkle, anti-fatigue composition making it possible to give the skin a radiant boost, a moisturizing or treating composition; an anti-sun or artificial tanning composition. The composition according to the invention can also be a hair product, in particular for maintaining the hairstyle or shaping the hair. The hair compositions are preferably shampoos, gels, styling lotions, brushing lotions, fixing and styling compositions such as lacquers or spray. Lotions can be packaged in various forms, in particular in vaporizers, pump-dispensers or in aerosol containers in order to ensure application of the composition in vaporized form or in foam form.

The subject of the invention is also a cosmetic process for making up or caring for keratin materials, in particular the skin of the body or of the face, nails, hair and / or eyelashes, comprising the application to said materials of a cosmetic composition as defined above.

The invention also relates to an adhesive composition comprising a copolymer in accordance with the invention. In this case, the copolymer is advantageously present in a content of at least 5% by weight relative to the total weight of the composition. The adhesive composition can comprise additives such as tackifying resins, plasticizers, such as oils, in which case it will constitute a hot-melt pressure-sensitive adhesive composition (known by the abbreviation HMPSA). The copolymers of the invention contribute to improving the mechanical properties of the adhesive compositions, in particular when they are exposed to high temperature (for example, tape of the post-it type deposited on a window pane in direct sunlight).

Generally, the oils to be used as plasticizers in HMPSA compositions are oils of the trimellitate type, such as trioctyl trimellitate, or even predominantly naphtenic oils such as Catenex N956 from Shell. It is not recommended to use oils of paraffinic type (typically Primol 352 oil, from Exxon-Mobil), of liquid polybutene type (typically Napvis 10) because, under certain conditions, they are incompatible with the copolymer and exude from the mixture. According to the invention, the tackifying resins are generally resins based on rosins such as Forai AX, of rosin ester such as Forai F85, the resins known under the name pure monomer such as Krystallex F85, polyterpenes such as DERCOLYTE A 115 from DRT, hydroxylated polyesters (typically Reagem 5110 from DRT), terpene styrene (typically DERCOLYTE TS 105 from DRT), terpene pentaerythritol (typically DERTOLINE P2L), resins based on terpene phenol (typically Dertophene T105 from DRT). The composition of the invention can be used as an adhesive, for constituting, for example, tapes, labels and adhesive tapes, in various fields, such as hygiene, wood, bookbinding, packaging. The invention also relates to the use of a copolymer as defined above as an ingredient of an adhesive composition. Finally, the invention relates to thermoplastic compositions. In this case, the copolymer is advantageously present in a content of at least 1% by weight relative to the total weight of the composition. As additives, such compositions may further comprise one or more thermoplastic polymers, such as polymethyl methacrylate, polystyrene and polyvinyl chloride. By using the copolymers of the present invention, it will be possible to increase the hardness of the thermoplastic polymers present in the composition. Finally, the invention relates to the use of a copolymer as defined above as an ingredient in a thermoplastic composition.

The invention is illustrated in more detail in the following examples. Tg measurement method

The glass transition temperatures of the sequences can be theoretical Tg determined from the theoretical Tg of the constituent monomers of each of the sequences, which can be found in a reference manual such as the Polymer Handbook, 3 ^rd ed, 1989, John Wiley, according to the following relationship, known as Fox's Law: wi being the mass fraction of the monomer i in the sequence considered and Tgi being the glass transition temperature of the homopolymer of the monomer i. Unless otherwise indicated, the Tg indicated for the sequences are theoretical Tg.

Molecular masses

The average molar masses eh weight (Mw) and number (Mn) are determined by liquid chromatography by gel permeation or GPC (solvent THF, calibration curve established with linear polystyrene standards, refractometric detector). The dispersion index is calculated as follows: Ip = Mw / Mn The GPC is carried out with STYRAGEL HR4 / 7.8 x 300 mm Columns, sold by Waters WAT044225. Detection is carried out with a WATERS 410 refractometer. The eluent is THF, at a flow rate of 1 ml / min. The volume injected is 50 microliter, at 25 ° C.

¹ block formed is characterized by GPC to determine the mass of the ^ERE sequence. The overall block copolymer is characterized by GPC so as to determine the mass of the total copolymer. The theoretical average mass by weight of a block is given by the ratio: (weight (g) of monomers constituting the block) / (weight (g) initiator).

The relative proportion in moles of the various monomers within the 1st block is determined by NMR:% monomer M1 = (% number of moles of M1) / (total number of moles of monomers in the block). The relative proportion of the different monomers between the 1st block and the second block is determined by NMR.

General synthesis process

The polymers of the examples are synthesized by the ATRP method: - in the presence of copper (Cul) in the form of copper halide such as, for example, CuBr (of 99% purity) supplied by Aldrich or CuCl (99% purity) supplied by ACROS, - with an initiator of the RBr type, - and a ligand of the amino type. As ligand, PMDETA or N, N, N ', N'',N''-pentamethyldiethylenetriamine from Fluka are used. The monomers are previously passed through an alumina column so as to eliminate the possible stabilizer.

The diblock synthesis takes place using a monofunctional initiator of the ethyl 2-bromoisobutyrate type supplied by Aldrich at a degree of purity 98%. The synthesis of tribloc proceeds by polymerization from the difunctional initiator of the type: 3- [(2-bromo-2-methylpropanoyl) oxy] propyl 2-bromo-2-methylpropanoate: (CH ₃ ) ₂ BrC-C (= 0) -0- (CH ₂ ) ₄ -0-C (= 0) - C (CH ₃ ) ₂ Br.

The polymerization proceeds in several stages: ^1st stage: formation of the first block by polymerization of the monomer (or mixture of monomers) constituting the first block according to the following general diagram: In a balloon, one introduces the quantities and natures of adequate monomers. A flow of argon is bubbled with stirring for 5 minutes, then the ligand is still introduced with stirring and under a flow of argon, copper and finally 1 initiator. Three vacuum / argon degassing cycles are carried out. The mixture is stirred, then, when it is homogeneous, it is placed in an oil bath at a temperature of 90 ° C (bath temperature). The polymerization takes place for a given time at 90 ° C. The polymer is purified by passage through an alumina column so as to separate the copper-based catalyst. The polymer is then precipitated in a water / methanol mixture (20/80) when cold (dry ice). The first block is thus obtained which plays the role of precursor (or macroinitiator) for the polymerization of the second sequence: it is a “functional” polymer comprising at its end a function capable of re-initiating the polymerization of a second monomer (or mixture of monomers) constituting the second block. We can schematize this precursor by: Polymer-Br

2 ^nd step: formation of the second block by polymerizing the monomer (or monomer mixture) at the end of the macroinitiator (polymer-Br) or (Br- polymer-Br)

To the macroinitiator, the ligand, the solvent and the copper are then added under a stream of argon, then the monomer or mixture of monomers. The mixture is cooled with liquid nitrogen. Once the mixture is frozen, three vacuum-argon degassing cycles are carried out. The mixture is allowed to return to the liquid state and then the reactor in an oil bath at a temperature of 90 ° C. The polymer is purified by passage through an alumina column so as to separate the copper-based catalyst. The final polymer is then precipitated in a water / methanol mixture (20/80) when cold (dry ice).

Example 1 Preparation of a diblock polymer poly (butyl acrylate-co-acrylic acid) -b— poly (methyl methacrylate-acrylic co-acid).

This polymer is prepared by hydrolysis of a poly (butyl acrylate-tert-butyl co-acrylate) -b-poly (methyl methacrylate-tert-butyl co-acrylate) diblock copolymer.

1 / Synthesis of pol (butyl acrylate-tert-butyl co-acrylate) -b-poly (methyl methacrylate-tert-butyl co-acrylate):

^1st step: synthesis of the poly (butyl acrylate-tert-butyl co-acrylate) macro-initiator -Br

According to the general process described above, the following mixture of monomers is polymerized in the following proportions:

Theoretical conversion fixed in%: 33 Reaction time: 3h35min

Characterization: - Theoretical Mw (g / mol): 31,939 - Mn measured by GPC (g / mol): 54,900 - Mw measured by GPC (g / mol): 59,500 - Mp (average mass at peak measured by GPC) (g / mol): 58,600 - Ip = 1.1

2nd step: polymerization of the methyl methacrylate / tert-butyl acrylate mixture at the end of the macro-initiator: poly (butyl acrylate-tert-butyl co-acrylate) -Br

The macroinitiator from the first step is introduced into a container equipped with an ovoid magnetic bar and allowed to evaporate for 12 hours under reduced pressure to remove as much as possible any residual monomers. The CPG is carried out just before the synthesis of the second block; the macro initiator and the final block are measured under the same conditions.

Theoretical conversion rate: 50% Reaction time: 10 hours

Characterization of the diblock copolymer formed: - theoretical Mw (g / mol): 118,117 - Mn measured by GPC (g / mol): 97,985 - Mw measured by GPC (g / mol): 114,579 - Mp (average mass at peak measured by GPC) (g / mol): 115 080 - Ip = 1.17

% relative to all of the monomers

2 / Synthesis of the diblock poly (butyl acrylate-acrylic co-acid) -b-poly (methyl methacrylate-acrylic acrylic acid)

The hydrolysis is carried out with trifluoroacetic acid on the tert-butyl acrylate unit. A 6-fold excess of acid over the tert-butyl unit is used.

Characterization of the hydrolyzed diblock copolymer

A diblock copolymer is finally obtained having the following distribution: - in mole%: poly (methyl methacrylate 97.1% -co-acrylic acid 2.9%) -b-poly (butyl acrylate 81.0% -co-acrylic acid 19.0% ) - in% by weight: poly (methyl methacrylate 97.9% -co-acrylic acid 2.1%) -b-poly (butyl acrylate 88.4% -co-acrylic acid 11.6%)

3 / Dissolution / aqueous dispersion of the polymer Neutralization of the acid units is carried out by adding amino-2-methyl-2-propanol (AMP). The polymer is dissolved in THF, then added with vigorous stirring using an Ultra Turax type agitator, AMP and water. We obtain a white milk with bluish reflections, not very viscous. Coulter particle size: 390 nm Dry extract of the solution: 18.1% by weight Example 2 Preparation of a poly (methyl methacrylate-co-methacrylic acid) -b- poly (butyl acrylate-co-methacrylic acid) -b-poly (methyl methacrylate-co-methacrylic acid) triblock.

This polymer is prepared by hydrolysis of a triblock copolymer poly (methyl methacrylate-tert-butyl co-methacrylate) -b-poly (butyl acrylate-tert-butyl methacrylate) -b- poly (methyl methacrylate-co-methacrylate tert-butyl)

1 / Synthesis of poly (methyl methacrylate-tert-butyl co-methacrylate) -b- pol (butyl acrylate-tert-butyl co-methacrylate) -b- poly (methyl methacrylate-tert-butyl co-methacrylate)

l ^st step: Synthesis of difunctional macroinitiator

Br-poly (butyl acrylate-tert-butyl co-methacrylate) -Br This macro initiator is synthesized by polymerization of the monomer mixture using a difunctional initiator: (CH ₃ ) ₂ BrC-C (= 0) -O- (CH ₂ ) ₄ -0- C (= 0) -C (CH ₃ ) ₂ Br Preparation of the difunctional polymerization initiator A difunctional initiator is prepared according to the following reaction scheme:

HO- (CH ₂ ) ₄ -OH + 2 (CH ₃ ) ₂ (Br) CC (= 0) Br • * (CH ₃ ) ₂ BrC-C (= 0) - 0- (CH ₂ ) 4-0- C (= 0) -C (CH ₃ ) ₂ Br

18 g (0.2 mole) of 1,4-butanediol are mixed with 100 g of tetrahydrofuran and the mixture is allowed to equilibrate for 10 minutes at room temperature. 40.4 g (0.4 moles) of triethylamine are then added slowly over a period of 30 minutes so that the temperature of the solution does not increase suddenly. Then added very slowly, over a period of 3 hours and while cooling to 5 ° C, 92 g (0.4 mole) of 2-bromoisobutyryl bromide. During this addition, a progressive yellowing of the reaction solution is observed. Stirring is continued overnight at 25 ° C, then the temperature is allowed to gradually rise to room temperature. The reaction solution is concentrated by evaporation of the THF and the residue is precipitated in water. The aqueous phase is then extracted 3 times with ethyl ether, then the ethereal phase is dried over magnesium sulfate. After evaporation of the ether, 63 g of bis (1,4-bromoisobutyrate of n-butyl) are thus obtained, which corresponds to a yield of 80%. According to the general process described above, the following mixture of monomers is polymerized in the following proportions:

Conversion of polymerization: 40% by weight Reaction time: 9hl5

Characterization: - Theoretical Mw (g / mol): 73,259 - Mn measured by GPC (g / mol): 68,400 - Mw measured by GPC (g / mol): 77,294 - Mp (average mass at peak measured by GPC) (g / mol): 75,292 - Ip = 1.13

2 ^ee step: polymerizing the mixture of methyl methacrylate-butyl methacrylate at the end of the precursor Br-difunctional poly (butyl acrylate-co-butyl methacrylate) -Br

The precursor is introduced into a container equipped with a magnetic ovoid bar and it is allowed to evaporate for 12 hours under reduced pressure to remove as much as possible any residual monomers.

Conversion of polymerization 30% by weight Reaction time: 70 min

Characterization of the triblock copolymer: - theoretical Mw (g / mol): 114 222 - Mn measured by GPC (g / mol): 103 727 - Mw measured by GPC (g / mol): 133 295 - Mp (average mass at peak measured per GPC) (g / mol): 114 983 - Ip = 1.29

2 / Obtaining poly (methyl methacrylate-co-methacrylic acid) -b- poly (butyl acrylate-co-methacrylic acid) -b-poly (methyl methacrylate-co-methacrylic acid).

To do this, the poly (methyl methacrylate-tert-butyl co-methacrylate) -b-poly (butyl acrylate-co-methacrylate) is hydrolyzed. tert-butyl) -b-poly (methyl methacrylate-tert-butyl co-methacrylate) previously prepared. The hydrolysis is carried out with trifluoroacetic acid on the tert-butyl acrylate unit. A 5-fold excess of acid over the tert-butyl unit is used. The polymer is dissolved at 30% in dichloromethane. The reaction takes place at room temperature for 16 hours.

In the end, a triblock polymer is obtained having the following distribution (% by weight in the triblock): poly (methyl methacrylate 3 .9-co-methacrylic acid 5.1) 15% -b- poly (butyl acrylate 86-co- methacrylic acid 14) 70% -b-poly (methyl methacrylate 34.9-co-methacrylic acid 15.1) 15%

3 / Dissolution / aqueous dispersion of the polymer Neutralization of the acid units is carried out by adding AMP to water. The polymer thus obtained is soluble in water.

Dry extract of the solution: 5.1% by weight pH = 8.5 Viscosity in water: 47.6 mPa.s (measured with a No. 02 needle with a torque of 38.1%), at 25 ° C and at a concentration of 20% by weight.

Example 3

The polymer of Example 1 is dissolved in water, in an amount of 15 g of polymer in 100 ml of water (solution at 15% by weight). A hair composition is obtained which can be packaged in a pump bottle for application to the hair; this composition brings coi fant to the hair. Example 4

The polymer of Example 2 is dissolved in water, in an amount of 15 g of polymer in 100 ml of water (solution at 15% by weight). A hair composition is obtained which can be packaged in a pump bottle for application to the hair; this composition brings styling to the hair.

Example 5

The polymer of Example 1 is dissolved in ethyl acetate, at a rate of 25 g of polymer in 100 ml of ethyl acetate (25% by weight solution). After adding the appropriate coloring materials, a nail varnish is obtained which can be applied to the nail.

Claims

CLAIMS 1. Linear, ethylenic, block copolymer comprising at least a first sequence and at least a second sequence, each sequence comprising at least one ionic hydrophilic unit, which may be different from one block to another, said hydrophilic unit ionic being present in each sequence at a rate of 2 to 100% by weight relative to the weight of said sequence.

2. Copolymer according to claim 1, in which the ionic hydrophilic monomer (s) are present in each block in an amount of 3 to 70% by weight, in particular from 5 to 50% by weight, or even from 8 to 30% by weight, relative to the weight of the sequence.

3. Copolymer according to one of the preceding claims, comprising two blocks (diblock) or three blocks (triblock), each of the blocks comprising at least one ionic hydrophilic monomer, present in an amount of at least 2% by weight relative to the weight of the sequence.

4. Copolymer according to one of the preceding claims, in which the ionic hydrophilic monomer (s) are chosen from anionic, cationic and amphoteric hydrophilic monomers, and their mixtures.

5. Copolymer according to one of the preceding claims, in which each of the blocks comprises at least one anionic hydrophilic monomer and / or at least one cationic hydrophilic monomer.

6. Copolymer according to one of the preceding claims, in which at least one block comprises both at least one cationic hydrophilic monomer and at least one anionic hydrophilic monomer.

7. Copolymer according to one of the preceding claims, comprising at least one anionic hydrophilic monomer of formula (I):

in which: - RI is a hydrogen atom or a linear or branched hydrocarbon radical, of type C _p H _{2p +} ι, with p being an integer between 1 and 12, inclusive; especially methyl, ethyl, propyl, butyl. - Z is a divalent group chosen from -COO-, -CONH-, -CONCH3-, -OCO- or -0-; preferably - COO- and -C0NH-. - x is 0 or 1, preferably 1. - R2 is a divalent carbon radical, saturated or unsaturated, optionally aromatic, linear, branched or cyclic, from 1 to 30 atoms of carbon, which may include 1 to 30 heteroatoms chosen from O, N, S, and P; - Y is a group chosen from -COOH, - S0 ₃ H, -OSO3H, -PO (OH) ₂ and -0PO (0H) ₂ ; -m is 0 or 1.

8. Copolymer according to claim 7, in which R2 is: - an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, tert-butylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene, n -tetradecylene, n-docosanylene; - a phenylene radical -C ₆ H ₄ - (ortho, meta or para) optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from 0, N, S, and P; or a benzylene radical -C ₆ H ₄ -CH ₂ - optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 8 heteroatoms chosen from O, N, S, and P; - a radical of formula -CH ₂ -CHOH ~, -CH ₂ - CH ₂ -CHOH-, -CH ₂ -CH ₂ -CH (NH ₂ ) -, -CH ₂ ~ CH (NH ₂ ) -, -CH ₂ -CH ₂ - CH (NHR ') -, -CH ₂ -CH (NHR') -, -CH ₂ -CH ₂ -CH (NR'R ") -, -CH ₂ - CH (NR'R") ~ , -CH ₂ -CH = CH- with R 'and R "representing a linear or branched C1-C18 alkyl, in particular methyl or ethyl.

9. Copolymer according to one of claims 7 to 8, in which the hydrophilic anionic monomer is chosen from acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, acid maleic, diacrylic acid, dimethylfumaric acid, citraconic acid, acrylamidopropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrene sulfonic acid, vinylbenzoic acid, vinylphosphoric acid, vinylsulfonic acid, vinylbenzene sulfonic acid, acrylamidoglycolic acid of formula CH2 = CH-C0NHCH (0H) C00H, vinylphosphonic acid; 2-carboxyethyl (meth) acrylate, methacrylate or sulfopropyl acrylate (CH ₂ = C (CH ₃ ) C0 ₂ (CH ₂ ) ₃ S0 ₃ H), methacrylate or sulfoethyl acrylate and vinyl ethylsulfone, 2- (methacryloyloxy) ethylphosphate of formula CH ₂ = C (CH ₃ ) C00C ₂ H ₄ 0P (0) (0H) ₂ ; diallyl maleate of formula C ₃ H ₅ -C0 ₂ -CH = CH-C0 ₂ -C ₃ H5; carboxylic anhydrides carrying a vinyl bond such as maleic anhydride, as well as their salts; and their mixtures.

10. Copolymer according to one of the preceding claims, comprising at least one cationic hydrophilic monomer of formula (II):

in which - RI, Z, x, R2 and m have the same meanings as in one of claims 7 to 8; - X is (a) a group of formula -NR ₆ R ₇ with R6 and R7 representing, independently of one another, (i) a hydrogen atom, (ii) a linear, branched or cyclic alkyl group , saturated or unsaturated, optionally aromatic, comprising from 1 to 30 carbon atoms, which may comprise 1 to 10 heteroatoms chosen from 0, N, S, and P; in particular a methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, lauryl, stearyl group; (iii) an alkylene oxide group of formula - (R80) _Y R9 with R8 representing a linear or branched C2-C4 alkyl, R9 is hydrogen or a linear or branched C1-C30 alkyl radical and y is between 1 and 250 inclusive; (iv) R6 and R7 can form with the nitrogen atom a saturated or unsaturated, optionally aromatic ring, comprising in total 5, 6, 7 or 8 atoms, and in particular 4, 5 or 6 carbon atoms and / or 2 with 4 heteroatoms chosen from O, S and N; said ring can also be fused with one or more other cycles, saturated or unsaturated, optionally aromatic, each comprising 5, 6 or 7 atoms, and in particular 4, 5, 6 or 7 carbon atoms and / or 2 to 4 hetero atoms chosen from 0, S and N; or X represents (b) a group -R'6-N-R'7- in which R'6 and R'7 form with the nitrogen atom a cycle, saturated or unsaturated, optionally aromatic, comprising in total 5, 6, 7 or 8 atoms, and in particular 4, 5 or 6 carbon atoms and / or 2 to 4 heteroatoms chosen from O, S and N; said cycle being able to be fused with one or more other cycles, saturated or unsaturated, optionally aromatic, each comprising 5, 6 or 7 atoms, and in particular 4, 5, 6, 7 or 8 carbon atoms and / or 2 to 4 heteroatoms chosen among O, S and N.

11. Copolymer according to claim 10, in which the cationic hydrophilic monomer is chosen from, alone or as a mixture: - 2-vinylpyridine, 4-vinylpyridine, allylamine and 1 allylpyridine; - the (meth) acrylates of ¹ aminoalkyls, such as the (meth) acrylates of [N, N-di (C1-C4) alkylamino] (C1-C6) alkyl or the (meth) acrylates of [N- (C1- C4) alkylamino] (C1-C6) alkyl and in particular N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, 2-aminoethyl (meth) acrylate, (meth) 2- (N-tertbutylamino) ethyl crylate; - aminoalkyl (meth) acrylamides, such as the (meth) acrylamides of [N, N-di (Cl- C4) alkylamino] (C1-C6) alkyl or the (meth) acrylamides of [N- (C1- C4) amino alkyl] (C1-C6) alkyl, and in particular N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide; 3-aminopropyl (meth) acrylamide; - vinylamine, vinylimidazole, 2- (diethylamino) ethylstyrene; - N-vinylimidazole, N-vinyl-2-methylimidazole, N-vinylcarbazole; as well as their salts and / or their quaternized forms.

12. Copolymer according to one of the preceding claims, comprising at least one amphoteric monomer of formula (III):

in which :

- Ri, Z, x, R2 and m have the same meanings as in formula (I) above;

- X ' ⁺ is a divalent group of formula - N ⁺ R' ₆ R 'i with R'6 and R'7 representing, independently of one another, (i) a hydrogen atom, (ii) a linear, branched or cyclic, optionally aromatic, alkyl group comprising from 1 to 30 carbon atoms, which may comprise 1 to 8 heteroatoms chosen from O, N, S and P; for example methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl or isobutyl; (iii) an alkylene oxide group. of formula - (R80) _y R9 with R8 representing a linear or branched C2-C4 alkyl, R9 is hydrogen or an alkyl radical, linear or branched, C1-C30 and there is between 1 and 250 inclusive; (iv) R'6 and R'7 can form a saturated or unsaturated, optionally aromatic, optionally aromatic, ring (NR '6R' 7 or R'6NR'7) with the nitrogen atom, comprising in total 5, 6, 7 or 8 atoms, and in particular 4, 5, 6 or 7 carbon atoms and / or 2 to 4 heteroatoms chosen from O, S and N; said cycle being able to be fused with one or more other cycles, saturated or unsaturated, optionally aromatic, each comprising 5, 6, 7 or 8 atoms, and in particular 4, 5, 6 or 7 carbon atoms and / or 2 to 4 heteroatoms chosen from 0, S and N. - Y ^{1 "is} a group selected from ^-COO" -S0 ₃ ^", -OS0 ₃ ^~, -P0 ₃ ^2_ and -P0 ^{2 ~} -. R 3 is a divalent carbon-based radical saturated or unsaturated, optionally aromatic, linear, branched or cyclic, from 1 to 30 carbon atoms, possibly comprising 1 to 18 heteroatoms chosen from O, N, S and P. - n is 0 or 1.

13. The copolymer according to claim 12, in which the radical R3 is: - an alkylene radical such as methylene, ethylene, propylene, n-butylene, isobutylene, isobutylene, n-hexylene, n-octylene, n-dodecylene, n-octadecylene , n-tetradecylene, n-docosanylene; - a p enylene radical -CeH ₄ - (ortho, eta or para) optionally substituted, by a C1-C12 alkyl radical optionally comprising 1 to 5 heteroatoms chosen from 0, N, S, F, Si and P; or a benzylene radical -CgH-CH ₂ - optionally substituted with a C1-C12 alkyl radical optionally comprising 1 to 5 heteroatoms chosen from 0, N, S and P.

14. Copolymer according to one of claims 12 to 13, in which the amphoteric hydrophilic monomer is chosen from, alone or as a mixture, N, N-dimethyl-N- (2-methacryloyloxyethyl) -N- (3-sulfopropyl) ammonium betaine, N, N-dimethyl-N- (3-methacrylamidopropyl) -N- (3-sulfopropyl) ammonium betaine and 1- (3-sulfopropyl) -2-vinylpyridinium betaine.

15. Copolymer according to one of the preceding claims, in which the copolymer comprises from 4 to 100% by weight, in particular from 8 to 80% by weight, or even from 10 to 30% by weight, relative to the total weight of the copolymer, of ionic hydrophilic units.

16. Copolymer according to one of the preceding claims, further comprising one or more additional monomers chosen from nonionic hydrophilic monomers, hydrophobic monomers and mixtures thereof,

17. The copolymer according to claim 16, in which the non-ionic hydrophilic monomer (s) are present in an amount of 0 to 98% by weight, relative to the weight of the block, in particular from 2 to 95% by weight, and even better of 3 to 92% by weight, in at least one block, or even in each block.

18. Copolymer according to one of claims 16 to 17, in which the hydrophobic monomer or monomers are present in an amount from 0 to 98% by weight, relative to the weight of the block, in particular from 2 to 95% by weight, and even better from 3 to 92% by weight, in at least one sequence, or even in each sequence.

19. Copolymer according to one of claims 16 to 18, in which the additional monomer is chosen from, alone or as a mixture,:

- (i) ethylene hydrocarbons having 2 to 10 carbons, such as ethylene, isoprene, or butadiene;

- (ii) the (meth) acrylates of formula:

in which R ₂ is hydrogen or methyl (CH ₃ ) and R ₃ represents: - a linear or branched alkyl group, from 1 to 30 carbon atoms, in which there are (are) optionally intercalated one or more heteroatoms selected from O, N, S and P; said alkyl group possibly also being optionally substituted by one or more substituents chosen from OH, halogen atoms (Cl, Br, I and F), and the groups -Si (R ₄ R ₅ R ₆ ) and - If (R ₄ R ₅ ) 0, in which R ₄ , R ₅ and R _s , identical or different, represent an atom hydrogen, a C1-C6 alkyl group or a phenyl group; - a C ₃ to C ₁₂ cycloalkyl group, such as the isobornyl group, - a C ₃ to C ₂ aryl group such as the phenyl group, - a C ₄ to C ₃₀ aralkyl group (C ₁ to C ₆ alkyl group) such as 2-phenyl-ethyl, t-butylbenzyl or benzyl, - a 4 to 12-membered heterocyclic group containing one or more heteroatoms chosen from 0, N, and S, the ring being aromatic or not, - a heterocycloalkyl group (alkyl of 1 to 4 C), such as furfurylmethyl or tetrahydrofurfurylmethyl, said cycloalkyl, aryl, aralkyl, heterocyclic or heterocycloalkyl groups possibly being substituted by one or more substituents chosen from hydroxyl groups, halogen atoms, and C1-6 alkyl groups 4, linear or branched in which there is (are) optionally intercalated (s) one or more heteroatoms chosen from 0, N, S and P, said alkyl groups being able, in addition, to be optionally substituted by one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and the groups -Si (R ₄ R ₅ Rs) and -Si (R ₄ R ₅ ) 0, in which R, R ₅ and R ₅ , identical or different, represent a hydrogen atom, a C1-C6 alkyl group, or a phenyl group, - a group - (0C ₂ H _{4) m} -0R '', with m = 5 to 300 and R "= H or alkyl of Ci to C _30, for example - (OC2H _{4) m} - OH, - (OC ₂ H ₄ ) _m -0-methyl or - (OC ₂ H) _m -0-behenyl; a group - (OC ₃ H ₆ ) _m -OR '', with m = 5 to 300 and R "= H or alkyl of Ci to C ₃₀ , for example - (OC3H6) _m -OH; or a statistical mixture or block of groups (0C ₂ H ₄ ) _m and (OC ₃ H ₆ ) _m .

- (iii) (meth) acrylamides of formula:

wherein Rs denotes H or methyl; and R7 and Rζ, identical or different, represent: - a hydrogen atom; or - a linear or branched alkyl group, from 1 to 30 carbon atoms, in which there are optionally intercalated one or more heteroatoms chosen from O, N, S and P; said alkyl group possibly also being optionally substituted by one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and groups -Si (R ₄ R ₅ R ₆ ) and -Si (R ₄ R) 0, wherein R, R ₅ and R ₆ represent a hydrogen atom, an alkyl group -C ₆ or phenyl; - a C ₃ to C _i cycloalkyl group, such as the isobornyl group, - a C ₃ to C ₂₀ aryl group such as the phenyl group, a C 1 to C 30 aralkyl group (C 1 to C 5 alkyl group) such as 2-ρhenyl-ethyl, t-butylbenzyl or benzyl, a heterocyclic group of 4 to 12 members containing one or more heteroatoms chosen from O, N, and S, the ring being aromatic or not, - a heterocycloalkyl group (C1-C4 alkyl), such as furfurylmethyl or tetrahydrofurfurylmethyl, said cycloalkyl, aryl, aralkyl, heterocyclic or heterocycloalkyl groups which may be optionally substituted by one or more substituents chosen from among hydroxyl groups, halogen atoms, and linear or branched C1-4 alkyl groups in which one or more heteroatoms are optionally intercalated, chosen from O, N, S and P, said groups alkyl which may, in addition, be optionally substituted by one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and the groups -Si (R ₄ R ₅ Rg) and -Si ( R ₄ R ₅ ) 0, in wherein R _4, R ₅ and R _6, identical or different, represent a hydrogen atom, an alkyl group -C ₆ or phenyl; - a group - (OC ₂ H _{4) m} -OR ^r, m = 5 to 300 and R "= H or alkyl of Ci to C _30, for example - (OC ₂ H _{4) m} - OH, - ( OC ₂ H ₄ ) _m -methyl or - (0C ₂ H ₄ ) _m -béhén le; a group - (OC ₃ H ₆ ) _m -OR ", with m = 5 to 300 and R" = H or C1 alkyl at C ₃₀ , for example - (OC ₃ Hs) _m -OH; or a statistical mixture or block of groups (OC ₂ H ₄ ) _m and (OC ₃ H6) _m . - (iv) vinyl compounds of formula: CH ₂ = CH-Rg, in which Rg is a hydroxyl group; halogen (Cl or F); an NH ₂ group; a group -ORχo where Rio represents a phenyl group or a C1-C12 alkyl group (the monomer is a vinyl or allyl ether); an acetamide group (NHC0CH ₃ ); an OCORn group where Ru represents a linear or branched alkyl group of 2 to 12 carbons (the monomer is a vinyl or allyl ester), C3-C12 cycloalkyl, C3-C20 aryl or C4-C30 arallyl; or Rg is chosen from: - a linear or branched alkyl group, comprising 1 to 30 carbon atoms, in which there are (are) optionally intercalated one or more heteroatoms chosen from O, N, S and P; said alkyl group possibly also being optionally substituted by one or more substituents chosen from -OH, halogen atoms (Cl, Br, I and F), and -Si groups (R ₄ R _S R ₅ ) and -Si (R ₄ R ₅ ) 0, in which R ₄ , R ₅ and R ₅ , identical or different, represent a hydrogen atom, a C ₆ to C ₆ alkyl group or a phenyl group; - a C ₃ to C ₁₂ cycloalkyl group such as isobornyl, cyclohexane, - a C ₃ to C ₂ o aryl group such as phenyl, - a C to C 30 arylalkyl or alkylaryl group (C 1 to C ₈ alkyl group) such as 2- phenylethyl or benzyl, - a 4 to 12-membered heterocyclic group containing one or more selected heteroatoms among O, N, and S, the ring being aromatic or not, such as N-vinylpyrrolidone and N-vinylcaprolactam; a heterocycloalkyl group (alkyl of 1 to 4 C), such as furfurylmethyl or tetrahydrofurfurylmethyl, said cycloalkyl, aryl, aralkyl, heterocyclic or heterocycloalkyl groups which may be optionally substituted by one or more substituents chosen from hydroxyl groups, halogen atoms , and alkyl groups of 1 to 4 C linear or branched in which there are (are) optionally intercalated (s) one or more heteroatoms chosen from 0, N, S and P, said alkyl groups being able, in addition, to be optionally substituted with one or more substituents chosen from -OH, the halogen atoms (Cl, Br, I and F) and the groups -Si (R ₄ R ₅ R ₆ ) and -Si (R ₄ R ₅ ) 0, in which R _4, R ₅ and Rζ, identical or different, represent a hydrogen atom, an alkyl group C _x -C ₆ or phenyl ,.

- (v) the allylic compounds of formula: CH ₂ = CH-CH ₂ -R ₉ or CH ₂ = C (CH ₃ ) -CH ₂ -R ₉ in which R9 has the same meaning as above.

- (vi) silicone (meth) acrylic, (meth) acrylamide or vinyl monomers.

20. Copolymer according to one of claims 16 to 19, in which the additional monomer is chosen from, alone or as a mixture,: - hydroxyalkyl (meth) acrylates and (meth) acrylamides in which the alkyl group comprises 2 to 4 carbon atoms, in particular 2-hydroxyethyl acrylate (Tg = 15 ° C), 2-hydroxyethyl methacrylate (55 ° C), 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, ( meth) N- (2-hydroxypropyl) acrylamide; - (meth) acrylates and

(meth) acrylamides of (Cι_ ₄ ) alkyl (Cι-) such as (meth) acrylates and (meth) acrylamides of methoxyethyle, 2-ethoxyethyl, methoxypropyl and di- (2-ethoxyethyl); - (meth) acrylamide and N, N-dimethylacrylamide; - (meth) acrylates and (meth) acrylamides group - (OC ₂ H _{4) m} -OR '', with m = 5 to 300 and R "= H or alkyl of Ci to C _4, e.g. (meth) acrylates and polyethylene glycol (meth) acrylamides (methoxy or hydroxy terminated); - vinyllactams such as vinylpyrrolidone and vinylcaprolactam; - vinyl ethers such as vinyl methyl ether (Tg = -34 ° C) and vinyl ethyl ether; - vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam; - polysaccharide (meth) acrylates such as sucrose acrylate and ethyl (glucoside) (meth) acrylate.

21. Copolymer according to one of claims 16 to 19, in which the additional monomer is chosen from, alone or as a mixture,: - t-butylbenzyl acrylate, t-butylcyclohexyl acrylate, acrylate isobornyl (94 ° C), furfuryl acrylate, n-hexyl acrylate (45 ° C), t-butyl acrylate (50 ° C), cyclohexyl acrylate (19 ° C), hydroxyethyl acrylate (15 ° C), methyl acrylate (10 ° C), ethyl acrylate (- 24 ° C), isobutyl acrylate (-24 ° C), l methoxyethyl acrylate (-33 ° C), n-butyl acrylate (-54 ° C), ethylhexyl acrylate (-50 ° C), hexyl acrylate, acrylate octyl, lauryl acrylate, isooctyl acrylate, isodecyl acrylate; - t-butylbenzyl methacrylate, t-butylcyclohexyl methacrylate, isobornyl methacrylate (111 ° C), methyl methacrylate

(100 ° C), cyclohexyl methacrylate (83 ° C), ethyl methacrylate (65 ° C), benzyl methacrylate (54 ° C), isobutyl methacrylate (53 ° C), methacrylate butyl (20 ° C), n-hexyl methacrylate (-5 ° C), ethylhexyl methacrylate, octyl methacrylate, lauryl methacrylate, isooctyl methacrylate, isodecyl methacrylate; - styrene (100 ° C), vinylcyclohexane, vinyl acetate (23 ° C), vinyl methyl ether (- 34 ° C), vinyl neononanoate, vinyl neododecanoate; N-butylacrylamide,

N-isopropylacryla-ïiide, la N, N ~ di-néthylacrylami e, la

N, N-dibutylacrylamide, N-t-butylacrylamide, N-octylacrylamide.

22. Copolymer according to one of claims 16 to 21, comprising at least one block comprising monomers chosen from n-hexyl methacrylate, ethyl acrylate, isobutyl acrylate, n- acrylate butyl, ethylhexyl acrylate; methoxy poly (ethylene glycol) mono methacrylate with a number m of ethlene glycol units of 8.12, 90, 180, 200; methoxy poly (ethylene glycol) mono methacrylamide with m = 8.12, 90, 180 or 200; poly (ethylene glycol) OH (meth) acrylate with m = 8.12, 90, 180 or 200; poly (ethylene glycol) OH (meth) acrylamide with m =

8.12, 90, 180 or 200; vinylpyrrolidone and vinylcaprolactam; vinyl methyl ether and vinyl ethyl ether;

23. Copolymer according to one of the preceding claims, comprising two blocks (diblocks), such as: poly (acrylic acid-butyl co-acrylate) -b-poly (methyl methacrylate-acrylic co-acid), and - poly (methacrylic acid-butyl co-acrylate) -b-poly (methyl methacrylate-methacrylic co-acid).

24. Copolymer according to one of the preceding claims, comprising three blocks (triblocks), such as: - poly (methyl methacrylate co acrylic acid) -b-poly (acrylic acid co butyl acrylate) -b-poly (methacrylate methyl co acrylic acid), - poly (methyl methacrylate co (meth) acrylic acid) -b-poly (methacrylic acid co butyl acrylate) -b-pol (methyl methacrylate co methacrylic acid), - poly ( methyl acrylate co acrylic acid) -b-poly (acrylic acid co butyl acrylate) -b-poly (methyl acrylate co acrylic acid), - pol (acrylic acid co butyl acrylate) -b-poly (methacrylate methyl co acrylic acid) -b-poly (acrylic acid butyl acrylate); - (acrylic polyacid) -b-poly (acrylic acid butyl acrylate) -b- (poly acrylic acid); - (methacrylic polyacid) -b-poly (methacrylic acid butyl acrylate) -b- (poly methacrylic acid); - poly (acrylic acid co acrylate of cyclohexyle) -b-poly (acrylic acid co acrylate of butyl) -b- poly (acrylic acid co cyclohexyl acrylate; - poly (acrylic acid co butyl acrylate) -b-poly (acrylic acid co cyclohexyl acrylate-b-poly (acrylic acid co butyl acrylate); - poly (acrylic acid co cyclohexyl methacrylate) -b-poly (acrylic acid co butyl acrylate) -b-poly (acrylic acid co cyclohexyl methacrylate; - poly (acrylic acid co isobornyl acrylate) -b-poly (acrylic acid co butyl acrylate) -b-poly (acrylic acid co isobornyl acrylate); - poly (methyl methacrylate co acrylic acid) -b-poly (acrylic acid co methoxypoly (ethylene glycol) mono methacrylate with m = 12) -b-poly (methyl methacrylate co acrylic acid); - poly (acrylic acid co methoxy poly (ethylene glycol) mono methacrylate with m = 12) -b- poly (methyl methacrylate co acrylic acid) -b- poly (acrylic acid co methoxy poly (ethylene glycol) mono methacrylate with m = 12).

25. Copolymer according to one of the preceding claims, in which at least one of the blocks of the copolymer has a glass transition temperature (Tg) less than or equal to 20 ° C.

26. Copolymer according to one of the preceding claims, in which at least one of the blocks of the copolymer has a glass transition temperature (Tg) greater than or equal to 20 ° C.

27. Copolymer according to one of the preceding claims, having a solution at 20% by weight in water, a viscosity at 25 ° C of between 1 and 10,000 centipoises (or mPa.s), in particular from 2 to 5 000 mPa.s and in particular from 5 to 3000 mPa.s.

28. Copolymer according to one of the preceding claims, characterized in that it is soluble or dispersible in water, at 25 ° C, in an amount of 5% by weight.

29. Cosmetic or pharmaceutical composition comprising, in a physiologically acceptable, in particular cosmetically or dermatologically acceptable, medium, at least one copolymer according to one of claims 1 to 28.

30. Composition according to claim 29, in which the copolymer (s) are present in an amount of 0.1% to 60% by weight, preferably 0.5% to 50% by weight, in particular 1% to 30% by weight , or even 2% to 20% by weight, relative to the total weight of the composition.

31. Composition according to one of claims 29 to 30, in which the copolymer is present in the composition in dissolved form, for example in water or an organic solvent, or else in the form of an aqueous or organic dispersion.

32. Composition according to one of claims 29 to 31, comprising at least one constituent chosen from water, hydrophilic organic solvents; a fatty phase, in particular consisting of fatty substances liquid at ambient temperature and / or solid fatty substances at ambient temperature such as waxes, pasty fatty substances, gums and their mixtures; one or more organic solvents, physiologically acceptable; a particulate phase which can comprise pigments and / or nacres and / or fillers; water-soluble or liposoluble dyes; film-forming polymers; vitamins, thickeners, gelling agents, trace elements, softeners, sequestering agents, perfumes, alkalizing or acidifying agents, preservatives, sun filters, surfactants, antioxidants, anti-hair loss agents hair, anti-dandruff agents, propellants, ceramides, or mixtures thereof.

33. Composition according to one of claims 29 to 32, which is in the form of a product for caring for and / or making up the skin of the body or the face, the lips and the hair, a sunscreen product or self-tanner, or even a product capillary.

34. Composition according to one of claims 29 to 33, being in the form of a hair product, in particular for maintaining the hairstyle or shaping the hair, such as shampoos, gels, lotions of styling, brushing lotions, fixing and styling compositions such as lacquers or spray.

35. An adhesive composition comprising a copolymer as defined according to any one of claims 1 to 28.

36. The adhesive composition according to claim 35, in which the copolymer is present in a content of at least 5% by weight relative to the total weight of the composition.

37. The adhesive composition according to claim 35, further comprising an additive chosen from tackifying resins, plasticizers.

38. Composition according to claim 37, in which the plasticizer is chosen from oils of the trimellitate type, oils which are mainly naphtenic.

39. Composition according to claim 37, in which the tackifying resin is chosen from resins based on rosin (s), rosin ester, polyterpene, hydroxylated polyester, terpene styrene, terpene pentaerythritol or terpene phenol.

40. Tapes, labels and adhesive tapes comprising a composition as defined according to any one of claims 35 to 39.

41. Use of a copolymer as defined in any one of claims 1 to 28 as an ingredient of an adhesive composition.

42. Thermoplastic composition comprising a copolymer as defined in any one of claims 1 to 28.

43. The thermoplastic composition according to claim 42, further comprising one or more thermoplastic polymers.

44. Thermoplastic composition according to claim 43, in which the thermoplastic polymer is chosen from polymethyl methacrylate, polystyrene and polyvinyl chloride.

45. Use of a copolymer as defined in any one of claims 1 to 28 as an ingredient of a thermoplastic composition.

46. Cosmetic process for making up or caring for keratin materials, in particular the skin of the body or face, nails, hair and / or eyelashes, comprising the application to said materials of a cosmetic composition as defined in one of claims 29 to 34.