EP3897858A1 - Composition comprising a modified photo-dimerizable polymer and an alkaline agent and/or an amino alkoxysilane derivative and treatment method implementing the composition - Google Patents

Abstract

The present invention concerns a composition comprising: - at least one photo-crosslinkable polymer comprising at least one photo-dimerizable pendant group; - one or more alkaline agent(s) and/or amino alkoxysilane derivative(s), the alkaline agent(s) and/or amino alkoxysilane derivative(s) being present in the composition in an amount ranging from 0.01 to 10% by weight relative to the total weight of the composition, the pH of the composition being greater than or equal to 7.

Description

TITLE: COMPOSITION COMPRISING A MODIFIED SAND PHOTODIMERI POLYMER AND AN ALKALINE AGENT AND / OR AN AMINE DERIVATIVE

ALCOXYSILANE AND TREATMENT METHOD USING THE COMPOSITION

The present invention relates to a composition, in particular a cosmetic composition, in particular a hair composition, comprising at least one modified photocrosslinkable polymer and an alkaline agent and / or an amino derivative of alkoxysilane in a particular content. Such a composition makes it possible to obtain a sheathing resistant to washing, the performance of which is stable over time. It is known to those skilled in the art to use photocrosslinkable materials such as materials from

vinyl monomers, and in particular (meth) acrylate monomers.

Thus, document US Pat. No. 5,300,285 describes a process for waving the hair and a composition for implementing this process, and in particular a neutralizing composition based on silicone, comprising a silicone with vinyl function, a photoinitiator with free radicals and a solvent. This composition acts as a substitute for neutralizing solutions based on hydrogen peroxide when applied to the hair after a process of permanent deformation of the hair and photocrosslinking of the composition. This composition has the advantage of working simultaneously as a keratin crosslinking agent, while giving the hair advantages such as conditioning and a soft feel. The photocrosslinking of the composition is triggered by the photoinitiator (generally a derivative of acetophenone), which releases a radical under irradiation in the UVA domain (350-385 nm).

Unfortunately, the photopolymerization of vinyl-functional silicone in the presence of a photoinitiator leads to an irreversible photocrosslinking of the vinyl-functional silicone. In other words, once photocrosslinked, the deposit cannot be easily and at any time removed from the hair.

Document EP1572139 describes a photodimerizable composition making it possible to deposit on keratin materials, in particular the hair. This document teaches that such deposits make it possible to obtain a residual deposit which provides lasting cosmetic properties over time and which can be easily removed. The deposits obtained from the crosslinkable compounds described in this document however exhibit limited persistence. Furthermore, the deposition of these compounds on the hair is not uniform and very dependent largely from the level of damage to the hair. Thus, the result is not uniform between the tip and the hairline.

To obtain a uniform deposit over the whole of the hair, it has already been proposed to use polymers with photodimerizable pendant groups and hydrophobic pendant groups, as described in particular in document WO2017108767. The photodimerizable polymer described is however not very stable over time. The performance and safety of the composition are not necessarily guaranteed over time.

There is a need to further improve the results obtained in terms of stability.

The present invention therefore aims to provide a composition comprising a photocrosslinkable polymer which does not have the drawbacks of the compositions of the state of the art. In particular, the objective of the invention is to develop photodimerizable compositions stable over time, which allow a cladding of keratin materials, and in particular of the hair, effective, homogeneous, reproducible and durable resistant to washing.

Thus, one of the objects of the present invention is a composition comprising:

- at least one photocrosslinkable polymer comprising at least one

grouping during photodimerizable;

- one or more alkaline agents and / or amino derivative (s) of alkoxysilane, the alkaline agent (s) and / or amino derivative (s) of alkoxysilane being present (s) ) in the composition in a content ranging from 0.01 to 10% by weight relative to the total weight of the composition, the pH of the composition being greater than or equal to 7.

Another object of the invention is a method for treating keratin materials comprising the application of said composition and a step

of irradiation of the composition on keratin materials to crosslink the composition.

This gives compositions which are stable over time and which make it possible to obtain a uniform sheathing of the hair which is persistent after washing.

Within the meaning of the present invention, and unless a different indication is given:

^■ an “alkylene chain” represents a divalent C1-C20 acyclic hydrocarbon chain; particularly in C1-C6, more particularly in C1-

C2 when the chain is linear; optionally substituted with one or several groups, identical or different, chosen from i) hydroxy, ii) (CrC2) alkoxy, iii) (poly) hydroxy (C2-C4) alkoxy (di) (Ci-C2) (alkyl) amino, iv) R ^a - Z ^a -C (Z ^b ) -Z ^c -, and v) R ^a -Z ^a -S (0) _t --Z ^c - with Z ^a , Z ^b , identical or different, representing an oxygen atom, of sulfur, or a group NR ^a ', Z ^c , representing a bond, an atom of oxygen, of sulfur, or a group NR ^a ; R ^a , representing an alkali metal, a hydrogen atom, an alkyl group or else is absent if another part of the cationic molecule and R ^a 'representing a hydrogen atom or an alkyl group; more particularly the groups iv) are chosen from carboxylate -C (0) 0 or -C (0) OMetal (Metal = alkali metal), carboxyl -C (0) -OH, guanidino H ₂ HC (NH ₂ ) -NH- , amidino H ₂ HC (NH ₂ ) -, (thio) ureo H ₂ NC (0) -NH- and H ₂ N- C (S) -NH-, aminocarbonyl -C (0) -NRa ' ₂ or aminothiocarbonyl - C (S) -NRa'2; carbamoyl Ra'-C (0) -NRa'- or thiocarbamoyl Ra'-C (S) -NRa'- with Ra ', identical or different, representing a hydrogen atom or a (CrC4) alkyl group;

^■ the groups "aryl" or "heteroaryl" or the aryl or heteroaryl part of a radical may be substituted by at least one substituent on a carbon atom selected from:

a C1-C16, preferably C Cs, alkyl radical optionally substituted by one or more radicals chosen from hydroxyl, C1-C2 alkoxy, (poly) hydroxy-C2-C4, acylamino, amino radicals substituted by two radicals C1-C4 alkyl, identical or different, optionally carrying at least one hydroxyl group or, the two radicals being able to form, with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, preferably of 5 or 6 members, saturated or unsaturated optionally substituted optionally comprising another heteroatom identical or different from nitrogen;

a halogen atom;

a hydroxyl group;

a C1-C2 alkoxy radical;

a C2-C4 (poly) hydroxyalkoxy radical;

an amino radical;

a 5- or 6-membered heterocycloalkyl radical; an optionally cationic 5 or 6-membered heteroaryl radical, preferably imidazolium, and optionally substituted by an (C ₁ -C ₄ ) alkyl radical, preferably methyl;

an amino radical substituted by one or two identical or different C ₁ -C ₆ alkyl radicals optionally bearing at least:

i) a hydroxyl group,

ii) an amino group optionally substituted by one or two optionally substituted C ₁ -C ₃ alkyl radicals, said alkyl radicals being able to form, with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or optionally substituted unsaturated optionally comprising at least one other heteroatom different or not from nitrogen,

iii) a quaternary ammonium group -N ⁺ R'R "R '", M for which R', R ", R '", identical or different, represent a hydrogen atom, or a C1-C4 alkyl group; and M represents the counterion of the organic, mineral acid or of the corresponding halide,

iv) or a 5 or 6-membered heteroaryl radical optionally cationic, preferably imidazolium, and optionally substituted by a (C ₁ -C ₄ ) alkyl radical, preferably methyl;

- an acylamino radical (-NR-C (O) -R ') in which the radical R is a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally carrying at least one hydroxyl group and the radical R 'is a C ₁ -C ₂ alkyl radical;

a carbamoyl radical ((R) ₂ NC (0) -) in which the radicals R, which may or may not be identical, represent a hydrogen atom, a C1-C4 alkyl radical optionally carrying at least one hydroxyl group;

an alkylsulfonylamino radical (R'-S (0) ₂ -N (R) -) in which the radical R represents a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally carrying at least one hydroxyl group and the radical R 'represents a C ₁ -C ₄ alkyl radical, a phenyl radical; an aminosulfonyl radical ((R) ₂ NS (0) ₂ -) in which the radicals R, which may or may not be identical, represent a hydrogen atom, a C ₁ -C ₄ alkyl radical optionally carrying at least one hydroxyl group , a carboxylic radical in acid or salified form (preferably with an alkali metal or ammonium, substituted or not);

a cyano group;

a nitro or nitroso group;

a polyhaloalkyl group, preferably trifluoromethyl;

the cyclic, cycloalkyl or heterocyclic part of a non-aromatic radical can be substituted by at least one substituent chosen from groups:

hydroxyl;

C1-C4 alkoxy, C2-C4 (poly) hydroxyalkoxy;

C1-C4 alkyl;

alkylcarbonylamino (RC (O) -N (R ') -) in which the radical R' is a hydrogen atom, a C1-C4 alkyl radical optionally carrying at least one hydroxyl group and the radical R is a radical C1-C2 alkyl, amino optionally substituted by one or two identical or different C1-C4 alkyl groups themselves optionally bearing at least one hydroxyl group, said alkyl radicals being able to form with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from nitrogen;

alkylcarbonyloxy (RC (O) -O-) in which the radical R is a C1-C4 alkyl radical, amino group optionally substituted by one or two identical or different C1-C4 alkyl groups themselves optionally bearing at least a hydroxyl group, said alkyl radicals being able to form, with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from nitrogen;

alkoxycarbonyl (RGC (O) -) in which the radical R is a C1-C4 alkoxy radical, G is an oxygen atom, or an amino group optionally substituted by a C1-C4 alkyl group itself optionally bearing '' at least one group hydroxyl, said alkyl radical possibly forming with the nitrogen atom to which they are attached, a heterocycle comprising from 5 to 7 members, saturated or unsaturated optionally substituted optionally comprising at least one other heteroatom different or not from nitrogen;

a cyclic, cycloalkyl, heterocyclic radical, or a part not

aromatic of an aryl or heteroaryl radical, can also be substituted by one or more oxo groups;

a cycloalkyl radical is a mono or bicyclic, hydrocarbon radical comprising from 3 to 10 carbon atoms, preferably from 4 to 7 carbon atoms such as cyclopentyl, or cyclohexyl;

a hydrocarbon chain is unsaturated when it has one or more double bonds and / or one or more triple bonds;

an “aryl” radical represents a mono carbon group or

polycyclic, condensed or not, comprising from 6 to 22 carbon atoms, and at least one ring of which is aromatic; preferably the aryl radical is a phenyl, biphenyl, naphthyl, indenyl, anthracenyl, or

tetrahydronaphthyl;

a “heteroaryl radical” represents a mono or polycyclic group, condensed or not, optionally cationic, comprising from 5 to 22 links, from 1 to 6 heteroatoms chosen from the nitrogen, oxygen, sulfur and selenium atom, and of which at least one cycle is aromatic;

preferably heteroaryl is selected from acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl, benzopyridazinyle, benzoquinolyl, benzothiazolyl, benzotriazolyl, benzoxazolyl, pyridinyl, tetrazolyl, dihydrothiazolyl, imidazopyridinyl, imidazolyl, indolyl, isoquinolyl, naphthoimidazolyle, naphthooxazolyle, naphthopyrazolyle, oxadiazolyl, oxazolyl, oxazolopyridyl , phenazinyl, phenooxazolyl, pyrazinyl, pyrazolyl, pyrilyl, pyrazoyltriazyle, pyridyle, pyridinoimidazolyle, pyrrolyle, quinolyle, tetrazolyle, thiadiazolyle, thiazolyle, thiazolopyridinyle, thiazoylimidazolyle, thiopyrylyle, thiopyrylyle

ammonium;

a “heterocyclic radical” is a radical which may contain one or two unsaturations but not aromatic, mono or polycyclic, condensed or not, containing from 5 to 22 links, comprising from 1 to 6 heteroatoms chosen from the nitrogen, oxygen, sulfur and selenium atom;

^■ a “heterocycloalkyl radical” is a heterocyclic radical comprising at least one saturated ring;

^■ a "cationic heteroaryl radical" is a heteroaryl group as defined above which comprises a quaternized cationic group endocyclic or exocyclic,

o when the cationic charge is endocyclic, it is taken up in the electronic delocalization by mesomeric effect, for example it is a pyridinium, imidazolium or indolinium group:

with R and R 'being a heterorayl substituent as defined above and particularly a (hydroxy) (Ci-C ₈ ) alkyl group such as methyl;

o when the charge is exocyclic, for example it is a substituent R ⁺

ammonium, phosphonium such as trimethylammonium, found outside of the heteroaryl such as pyridinyl, indolyl, imidazolyl, or naphthalimidyl in question:

with R a heteroaryl substituent as defined above and R ⁺ an ammonium group R _a R _b R _c N ⁺ -, phosphonium R _a R _b R _c P ⁺ - or ammonium

R _a R _b R _c N ⁺ - (Ci-C ₆ ) alkylamino with R _a , R _b and R _c identical or different represent a hydrogen atom or a group (Ci-Cs) alkyl such as methyl;

^■ a “cationic aryl with an exocyclic charge” means an aryl ring in which the quaternized cationic group is found outside of said cycle, it is in particular a substituent R ⁺ ammonium, or

phosphonium such as trimethylammonium, found outside the aryl such as phenyl, or naphthyl:

an “alkyl radical” is a linear or branched C1-C20 hydrocarbon radical, preferably C Cs;

an “alkenylene radical” is a divalent unsaturated hydrocarbon radical as defined above which may contain from 1 to 4 double bonds -C = C-, conjugated or not; particularly the alkenylene group contains 1 or 2 unsaturation (s);

the expression “optionally substituted” attributed to the alkyl radical implies that the said alkyl radical may be substituted by one or more radicals chosen from the radicals i) hydroxyl, ii) C1-C4 alkoxy, iii) acylamino, iv) amino optionally substituted by one or two identical or different C1-C4 alkyl radicals, said alkyl radicals being able to form, with the nitrogen atom carrying them, a heterocyle comprising from 5 to 7 members, optionally comprising another heteroatom different from or not from nitrogen; v) or a quaternary ammonium group -N ⁺ R'R "R '", M for which R', R ", R '", identical or different, represent a hydrogen atom, or a C1-C4 alkyl group, or -N ⁺ R'R ”R '” forms a heteroaryl such as imidazolium optionally substituted by a C1-C4 alkyl group, and M represents the counterion of the organic acid, mineral or of the corresponding halide;

an "alkoxy radical" is an alkyl-oxy radical for which the alkyl radical is a hydrocarbon radical, linear or branched, preferably C1 to C16; when the alkoxy group is optionally substituted, this implies that the alkyl group is optionally substituted as defined above;

by “organic or inorganic acid salt” is meant more particularly the salts chosen from a salt derived from i) hydrochloric acid HCl, ii) acid hydrobromic HBr, iii) sulfuric acid H2SO4, iv) alkylsulfonic acids: Alk-S (O) ₂ 0H such as methylsulfonic acid and ethylsulfonic acid; v) arylsulfonic acids: Ar-S (0) ₂ 0H such as benzene sulfonic acid and toluene sulfonic acid; vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid, x) alkoxysulfinic acids: Alk-0-S (0) 0H such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H3PO4; xiii) acetic acid CH3C (0) OH; xiv) triflic acid CF3SO3H and xv) tetrafluoroboric acid HBF ₄ ;

^■ by “anionic counterion” is meant an anion or a group

anionic derived from organic or mineral acid salt counterbalancing the cationic charge of the dye; more particularly the anionic counterion is chosen from i) halides such as chloride, bromide; ii) nitrates; iii) sulfonates including C1-C6 alkylsulfonates: Alk-S (O) 20 such as methylsulfonate or mesylate and ethylsulfonate; iv) arylsulfonates: Ar-S (0) ₂ 0 such as benzenesulfonate and toluenesulfonate or tosylate; v) citrate; vi) succinate; vii) tartrate; viii) lactate; ix) alkyl sulphates: Alk-0-S (0) 0 such as methysulphate and ethyl sulphate; x) arylsulfates: Ar-0-S (0) 0 such as benzenesulfate and toluenesulfate; xi) alkoxysulfates: Alk-0-S (0) ₂ 0 such as methoxy sulfate and ethoxysulfate; xii) aryloxysulfates: Ar-0-S (0) ₂ 0, xiii)

phosphates 0 = R (0H) ₂ -0- _, 0 = R (0> 0H 0 = P (0) ₃ , H0- [P (0) (0-)] _w -P (0) (0-) ₂ with w being an integer; xiv) acetate; xv) triflate; and xvi) borates such as tetrafluoroborate, xvii) disulfate disulfate (0 =) ₂ S (0) ₂ or SO4 ² and monosulfate HSO4;

the anionic counterion, derived from an organic or mineral acid salt, ensures the electroneutrality of the molecule so it is understood that when the anion comprises several anionic charges then the same anion can be used for the electroneutrality of several cationic groups in the same molecule or can be used for the electroneutrality of several molecules; for example the polymers which comprise two cationic entities can contain either two anionic counter ions "monoloaded" or either contains an anionic counterion "bicharged" such as (0 =) ₂ S (0) ₂ or 0 = P (0) ₂ - 0H; ^■ moreover, the addition salts which can be used in the context of the invention are in particular chosen from addition salts with a cosmetically acceptable base such as the basifying agents as defined below such as the alkali metal hydroxides such as soda, potash, ammonia, amines or alkanolamines;

^■ the expression “at least one” is equivalent to “one or more”; and

^■ the expression “inclusive” for a range of concentrations means that the limits of the range are part of the defined range. By “photodimerizable” group is meant, within the meaning of the present invention, a chemical group leading to photodimerization reactions under irradiation. In the context of the invention, photodimerization is a chemical reaction between two double bonds (of type 2 + 2) or two pairs of double bonds (of type 4 + 4), and more particularly between two double bonds (of type 2 +2).

The case of a reaction between two double bonds can be schematized as follows:

These photodimerization reactions are defined in the document

"Advanced Organic Chemistry, J Marck, 4 ^th edition, Wiley Interscience, NY 1992, p

855 ”.

Thus, the double bond, when it is photo-stimulated, generally when it is subjected to UV radiation, is capable of reacting with another double bond by cyclization.

According to the present invention, the double bond is said to be activated, that is to say that it is spontaneously photodimerizable without requiring the presence of a photoinitiator or of a chemical initiator.

The activation of this double bond is generally induced by the presence of an electron-withdrawing substituent in the alpha position of this photodimerizable double bond. As electron-withdrawing substituents, mention may be made of aromatic rings, such as the phenyl group optionally substituted by one or more halogen atoms, or electron-withdrawing groups such as NO2, CN, R'- YC (Y ') -, R'-C (Y') - Y-, R'-YC (Y ') - Y-, R'-YS (0) ₂ -, -S (0) ₂ -Y- R ', with R' representing a hydrogen atom or a (CrC4) alkyl group optionally substituted by one or more halogen atoms, Y, and Y ', identical or different representing an oxygen, sulfur or NR atom ”With R” representing a hydrogen atom or a (Ci-Ce) alkyl group.

The method according to the invention comprises a step a) of applying a composition comprising a polymer comprising at least one group during photodimerisable.

Preferably, the photodimerizable pendant groups which can be used according to the invention are chosen from monovalent radicals of formulas (I) and (II) below:

as well as their geometric isomers,

formulas (I) and (II) in which:

- Y and Z independently denote each other a nitrogen atom or a C (R) group with R representing a hydrogen atom or a (CrC4) alkyl group such as methyl;

A represents a bond or a divalent group chosen from the radicals (CrC ₈ ) alkylene, arylene, heteroarylene, cycloalkylene,

heterocycloalkylene, (thio) carbonyls, (C2-C8) alkenylenes and combinations thereof;

B represents a monovalent group chosen from alkyl (Cr Cs) radicals, aryl radicals, optionally cationic heteroaryl, cycloalkyl, optionally cationic heterocycloalkyl,

(thio) carbonyls, (C2-C8) alkenyls and combinations thereof; - X represents a divalent group chosen from the radicals (C2-

C ₈ ) alkylene, arylene, heteroarylene, cycloalkylene, heterocycloalkylene, (thio) carbonyls, (C2-C8) alkenylenes and combinations thereof; p represents an integer inclusive between 1 and 5, in particular between 1 and 3, preferably p is 1; represents the bond which connects the part of the monovalent radical to the rest of the molecule;

and

each of the groups mentioned possibly being substituted by one or more halogen atoms or groups chosen from

(Ci-Ce) alkyl, hydroxy, amino, (di) (Ci-C ₆ ) alkylamino, phenyl, carboxy, (Ci-Ce) alkoxy, (Ci-C ₆ ) alkoxy (thio) carbonyls, hydrogen (thio) groups - carbonyls, sulfonato R-0-S (0) ₂ - or RS (0) ₂ -0-, amide RR'NC (O) - or R- C (0) -N (R ') - or acyl RC ( O) -, ammonium RR'R ”N ⁺ - with R, R ', and R”, identical or different, representing a hydrogen atom or a group

(C1-C4) alkyl.

The pendant groups which can be dimerized according to the invention are in particular those cited in patents US-2,811, 510, EP 0 313 220, ER 0 313 221, EP 092 901, GB 2 030 575 and GB 2 076 826, as well as in the articles "Chemical review Vol 83.5 1983, p 507" "Polym, Paint color Journal 1988, 178, p 209" and "Current Trends in Polymer Photochemistry, Ellis Morwood Edition, NY, 1995".

By way of example, mention may more particularly be made of the photodimerizable pendant groups chosen from monovalent radicals of the following compounds:

- Stilbene,

- Styrylpyridinium (stilbazolium) of formula and their geometric isomers:

(Ai) (AO where

R ¹ and R ³ , identical or different, represent a halogen atom or a (C1-C6) alkyl group; or then two contiguous R ¹ or R ^{3 groups} form together with the carbon atoms which carry it a benzo group;

R ² represents the hydrogen atom, a (Ci-Ce) alkyl group optionally substituted by one or more halogen atoms such as chlorine or hydroxy, preferably R ² represents a (Cr C ₆ ) alkyl group such as methyl, ethyl, propyl;

q and r represent an integer inclusive between 0 and 4; and Q, represents an anionic counter ion preferably chosen from halide ions such as chlorides, bromides, iodides, perchlorates, tetrafluoroborates, methylsulfate, phosphates, sulfates, methanesulfonates, p-toluenesulfonate;

represents the bond which connects the part of the monovalent radical to the rest of the molecule, it being understood that the group for Â2 can be linked to the rest of the molecule via R ² ;

preferably the bond is on the phenyl in the para position of the styryl group on Ai or linked to the rest of the molecule via R ² on A ₂ ;

preferably the styryl group of Ai and Â2 is found in para of the pyridinium group; - styrylazolium of formula and their geometric isomers:

or

• A represents a sulfur atom, an oxygen atom, or an NR ² or C (R ² ) _{2 group} ; and , Q, r, q, R ¹ , R ² , and R ³ being as defined above, preferably the bond is on the phenyl in the para position of the stryryl group, styrylpyrazine,

chalcone,

(thio) cinnamate and (thio) cinnamamide,

maleimide,

(thio) coumarin,

- thymine,

uracil,

butadiene

anthracene,

pyridone,

pyrrolizinone,

acrizinium salts,

- furanone,

phenylbenzoxazole, and

their derivatives. According to a particular embodiment, the pendant or photodimerizable groups are chosen from:

a) the photodimerizable group (s) carrying a stylbazolium function of formula (la) or (Ib) and their geometric isomers:

in which:

R represents a hydrogen atom, a C1-C4 alkyl or C1-C4 hydroxyalkyl group;

R ’represents a hydrogen atom or a C1- alkyl group

C ₄ , and

X- denotes an anionic counter ion preferably chosen from halide ions such as chlorides, bromides, iodides, perchlorates,

tetrafluoroborates, methylsulfate, phosphates, sulfates, methanesulfonates, p-toluenesulfonate; preferably the group styryre is in para of the group

- 1 ~ - pyridinium and / or para of the bond

in which

R ”denotes a divalent alkylene radical having from 2 to 8 carbon atoms,

R ’represents a hydrogen atom or a C 1-6 alkyl group

C ₄ , and

X having the same meaning as that described for the preceding formula (la);

having the same meaning as before;

preferably the styryre group is found in para of the pyridinium group; or b) the photodimerizable groups carrying a styrylazolium function of formula (IIa):

X- (lia)

in which :

- R denotes a hydrogen atom, an alkyl group in C ₁ -C ₄ hydroxyalkyl or C ₁ -C ₄ alkyl;

A denotes a sulfur atom, an oxygen atom, or an N R 'or C (R') ₂ , R 'group; with R 'representing the hydrogen atom or a C ₁ -C ₄ alkyl group, R' preferably representing the hydrogen atom; and - X having the same meaning as that described for the preceding formula (la);

having the same meaning as before; preferably the styryre group is on the phenyl in para. Such pendant photodimerizable groups have activated double bonds, so that the photodimerization of these double bonds is triggered spontaneously in the UVA domain, without requiring any

photoinitiator.

By photoinitiator is meant, within the meaning of the present invention, a compound which initiates the photodimerization reaction and releases a radical under irradiation, in particular in the UV field.

According to a particular embodiment, the composition of the invention is free of photoinitiator. According to a particular embodiment of the invention, the polymer can comprise one or more hydrophobic pendant groups.

Mention may be made, as group during hydrophobic:

- saturated or unsaturated (Ci-C ₃ o) alkyl groups, optionally substituted and / or interrupted by one or more heteroatoms,

- alkenyl groups, - Aryl groups such as phenyl, pyridyl, furyl, Indoyl, benzofuryl. thiophenyl, imizadoyl, oxazoyl, thiazoyl, pyrazinyl, pyrimidinyl;

- fluorinated groups such as fluorinated carbon groups, such as -CF3, - CHF ₂ , -OCFS, -SCF ₃ , CF ₃ C (0) -,

- silicone groups such as -SiR _a R _b R _c such as -Si (CH ₃ ) ₃ ,

polydimethylsiloxane-PDMS, -Si (OR) ₃ , PDMS a, w diaminopropyl,

PDMS a, w dihydroxyalkyl, PDMS a, w dicarboxyalkyl, with R _a , R _b and R _c , identical or different, representing a (Ci-Cs) alkyl group optionally interrupted and / or terminated by one or more non-contiguous heteroatoms such as O, or S; and R representing a (Ci-Ce) alkyl group.

Preferably the hydrophobic pendant group (s) are chosen from a (C2-C22) alkyl group, more preferably from a (C ₃ - C1 ₆ ) alkyl and in particular propyl group.

The polymer backbone can be varied in nature. This polymer backbone can be natural or synthetic. Mention may be made, as skeletons of natural polymers, of polysaccharides.

Mention may be made, as polysaccharide, of xanthan, carrageenan, chitosan, cellulose and its derivatives, alginate, starch, dextran, pullulan, galactomannan and their biologically acceptable salts, as well as their derivatives.

As synthetic skeleton, mention may be made of polyvinyl polymers and polydiorganosiloxanes.

Among the poly (vinyl) polymers, mention may be made of poly (vinyl acetate), partially or completely hydrolyzed and polyvinyl alcohol (PVA).

Regarding polymers with pendant groups

photodimerizable carrying a stylbazolium function, they are obtained by reaction of the polymer considered with a chemical entity comprising a group of formula (la) or (Ib).

Preferably, the chemical entity comprising a group (la) carries a reactive group W of aldehyde or acetal type.

As chemical entities which can be used to graft

groups of the styrylpyridinium type, mention may especially be made of the quaternary salts of 2- (4-formylstyryl) -pyridinium, 4- (4-formyl-styryl) -pyridinium, 2- (3-formylstyryl) - pyridinium, N-methyl-2 - (4-formylstyryl) pyridinium, N-methyl-3- (4-formylstyryl) - pyridinium, N-methyl-2- (3-formylstyryl) -pyridinium, N-methyl-2- (2- formylstyryl) pyridinium, N-ethyl-2- (4-formyl-styryl) -pyridinium, N- (2- hydroxyethyl) -2- (4-formylstyryl) -pyridinium, N- (2-hydroxyethyl) -4- (4-formylstyryl) -pyridinium, N- methyl-4- (4-formylstyryl) -pyridinium, N-methyl-4 - (3-formylstyryl) -pyridinium.

The quaternary pyridinium salts can be chlorides, bromides, iodides, perchlorates, tetrafluoroborates, methosulfates, phosphates, sulfates, methanesulfonates, p-toluenesulfonates salts. Such chemical entities are described in GB-A-2030575.

As examples of entities, mention may be made of 4- (4-formylphenylethenyl) 1- methylpyridiunium methosulfate, 1- (3-ethoxycarbonylmethyl) -4- [2- (4- formylphenyl) ethenyl] pyridinium bromide, 1- ( methoxycarbonylpropyl) -4- [2- (4- formylphenyl) ethenyl] pyridinium bromide. Such entities are described in US 2007/0112094.

Preferably, n-methyl-4- (4-formylstyryl) pyridinium is used

methylsulfate (RN = 74401-04-0), in particular marketed by the company WAKO.

The synthesis, described below, of these polymers functionalized by photodimerizable groups such as those comprising a styryl group and hydrophobic groups can be carried out on the basis of the protocol of T. Uhlich et al. (Reactive & Functional Polymers, 28, 55-40 (1995)).

Compound of formula (III) to (Vlll ·) in which,

R, identical or different, represents a hydrogen atom, or a (Ci-Cio) alkyl group, optionally substituted and / or interrupted by one or more heteroatoms, preferably R represents a hydrogen atom or a group (Cr C4 ) alkyl such as methyl, ethyl, or propyl, more preferably R represents a hydrogen atom;

R ¹ represents a hydrogen atom, or a (Ci-Cio) alkyl group, optionally substituted and / or interrupted by one or more heteroatoms, preferably R ¹ represents a hydrogen atom or a (CrC4) alkyl group; R ² represents a (CrC ₃ o) alkyl group, saturated or unsaturated, optionally substituted and / or interrupted by one or more heteroatoms, an alkenyl group, an aryl group such as phenyl, pyridyl, furyl, Indoyl, benzofuryl. Thiophenyl, imizadoyle , oxazoyl, thiazoyl, pyrazinyl, pyrimidinyl; a fluorinated group such as a fluorinated carbon group such as -CF ₃ , -CHF ₂ , -OCF ₃ , -SCF ₃ , CF ₃ C (0) -a silicone group such as -SiR _a RbR _c such as -Si ( CH3) 3, polydimethylsiloxane-PDMS, -Si (OR) 3, PDMS a, w diaminopropyl, PDMS a, w dihydroxyalkyl, PDMS a, w dicarboxyalkyl, with R _a , R _b and R _c , identical or different, representing a group (Ci-Cs) alkyl optionally interrupted and / or terminated by one or more non-contiguous heteroatoms such as O, or S; and R representing a (Ci-Ce) alkyl group; preferably R ² represents a (C ₂ -C ₂₂ ) alkyl group, more preferably (C ₃ -Cie) alkyl;

A represents a group derived from photodimerizable compound preferably styrylpyridinium such as (I), (II), (Ai), (A ₂ ), (la), (Ib) or (lia) as defined

previously, more particularly chosen from (Ai) or (la) as defined above;

X represents an oxygen atom or a sulfur, preferably oxygen;

X 'and X ”represent an oxygen or sulfur atom or an N (R ³ ) group with R ³ represents a hydrogen atom or a (CrC ₄ ) alkyl group, preferably X' and X” represent an oxygen atom;

Mostly the products obtained are of formula (VI).

Advantageously, these chemical entities react with a polymer of polyvinyl alcohol or polyvinyl acetal type as described in the documents cited above and also such as the polymer (III) described in the above diagram for which X, X 'and X ”represent an atom of oxygen, R and R ¹ being as described above.

For example, a polyvinyl alcohol graft polymer comprising units of the following structure is thus obtained, A representing a group (I), (Ai) or (la):

Polyvinyl alcohol polymers grafted with a stryrylpyridinium group are especially described in the publication Ichimura K et al, Preparation and Characteristics of photocross-linkable poly (vinyl alcohol), Journal ofpolymer science, polymer chemistry edition, Vol 20, 1419-1432 (1982).

The polymers can be obtained by reacting polyvinyl alcohol or polyvinylacetate partially hydrolyzed with styrylpyridinium salts with formyl or acetal group as described in GB-A-2030575, WO 96/29312, US 5061603, GB-A-2076826, EP -A-092901.

Cellulose polymers grafted with styrylpyrydinium groups are in particular described in US 2007/0112094.

Preferably, the chemical entity comprising a group (Ai) or (la) carries a reactive group which is a halogen atom such as chlorine.

In this variant, the chemical entity corresponds for example to the formula:

Advantageously, the photocrosslinkable polymer comprising the groups (Ib) is for example obtained by reaction of the above entity with the polysaccharide chosen from those defined above.

For their part, the polymers having photodimerizable groups carrying a styrylazolium function are obtained by reaction of the polymer with a chemical entity comprising a group of formula (IIa).

Preferably, the chemical entity comprising a group (11a) carries a reactive group W of aldehyde or acetal type.

As chemical entities which can be used to graft

groups of the styrylazolium type, mention may be made of those described in EP-A-313220.

Advantageously, these chemical entities react with a polymer of polyvinyl alcohol or polyvinyl acetal type as described in the documents cited above. A polyvinyl alcohol graft polymer comprising units of the following structure is thus obtained

with B corresponding to the group

or (11a) as defined above.

Polyvinyl alcohol polymers grafted with a styrylazolium group are especially described in EP-A-313220. In this document, these polymers can be obtained by reacting polyvinyl alcohol or partially hydrolyzed polyvinylacetate with styrylazolium salts containing an aldehyde or acetal group.

According to one embodiment, the polymer carrying the photodimerizable group (s) is in the form of particles, in particular dispersed particles. Thus, in the latter case, the polymer particles are more particularly polyvinyl alcohol particles.

According to a preferred embodiment, the polymer carrying the photodimerizable group (s) of the invention is soluble in the cosmetic medium.

Thus, according to an alternative embodiment, the polymer is a polyvinylacetate (PVA) type polymer partially functionalized by one or more function (s). hydroxyl (s) and one or more function (s) of formula (IX):

The degree of polymerization of the PVA can be between 100 and 5000 and the substitution rate, in% of functions of formula (I) as defined above, can be between 0.1 and 25.

The following diagram represents a variant where the polymer is the polymer (III) as defined above carrying functions grafted by stylbazolium entities such as those of formula (A1) as defined above, which is capable of crosslinking under the effect of light, as shown below.

These materials react to radiation which may have both a UV light and visible light component, in particular a low dose of UV. Preferably, the following diagram represents the polymer which is PVA-SbQ (polymer of PVA acetate type carrying some hydrolysed functions and some functions grafted by stylbazoliums entities), which is capable of crosslinking under the effect of light, as illustrated below. after.

These materials are particularly appreciated because they do not require a photoinitiator and react to radiation which may comprise both a component in UV light and in visible light, in particular a low dose of UV.

Pendant groups with reactivity in both UV and visible light are preferred.

According to another alternative embodiment, the photocrosslinkable polymer is represented by a natural polymer which is functionalized by photodimerizable groups.

It can in particular be a polysaccharide which can in particular be chosen from chondroitin sulfate, keratan, keratan sulfate, heparin, heparin sulfate, xanthan, carrageenan, hyaluronic acid, chitosan, cellulose and its derivatives, alginate, starch, dextran, pullulan, galactomannan and their biologically acceptable salts.

The degree of functionalization is of course adjusted in order to be able to confer the degree of crosslinking required during activation.

According to the invention, the degree of functionalization in a photodimerizable pattern is at least 0.1%, or even at least 0.5%, or even at least 2%. Preferably, in a composition according to the invention, the photodimerizable groups are carried by a polymer of the polyvinylacetate or polysaccharide type.

The crosslinkable polymer can be carried in an aqueous medium.

The composition may contain a single polymer carrying pendant photodimerizable groups of different or different nature.

It is also possible to use a mixture of polymers having different functions.

Consequently, the reactions can be carried out between two photodimerizable groups of the same chemical nature or not.

The activated double bonds can react with another double bond of the same chemical nature or react with another double bond with a different chemical nature.

As an example of a polymer useful in the invention, mention may be made of the PVA polymer comprising pendant groups below called PVA-SbQ-propional in which preferably the amount of SbQ unit is between, limits included, 0, 5 and 5 mol%, preferably between 2 and 4 mol%, for example of the order of 2 mol%, the amount of propional group is between, limits included, 2 and 20 mol%, preferably between 5 and 15 mol%, for example of the order of 10 mol%, the amount of hydroxyl group is between, limits inclusive, 50 and 97.5 mol%, preferably between 60 and 97.5 mol%, for example around 86% molar:

with Q as defined above preferably CH ₃ OSO ₃ mesylate;

According to a particular embodiment, the molecular weight Mw of the PVA is between 10,000 and 100,000 g / mol, preferably between 25,000 and 80,000 g / mol.

According to a particular embodiment, the molecular weight Mw is of the order of 27,000 g / mol.

The polymer (s) comprising at least one group

photodimerizable represents (s) preferably 0.01 to 25%, better 0.1 to 20%, and better still 1 to 15% of the total weight of the composition.

The composition according to the invention can, in addition, comprise an effective amount of at least one photosensitizer.

By photosensitizer is meant in the sense of the present invention, an ingredient which modifies the wavelength of the irradiation, thus triggering the photodimerization reaction.

For example, the photodimerization of dimethylmaleimide groups is triggered by irradiation centered on the wavelength range from 270 to 300 nm. In the presence of a photosensitizer such as thioxanthone, photodimerization becomes effective with irradiation centered on the wavelength range from 360 to 430 nm.

Among the photosensitizers which can be used according to the invention, there may be mentioned in particular thioxanthone, bengal rose, phloxin, eosin, erythrosin, fluorescein, acriflavin, thionin, riboflavin, proflavin, chlorophylls , hematoporphyrin, methylene blue and mixtures thereof.

In practice, the photosensitizer which can be used according to the invention represents 0.00001% to 5% by total weight of the composition.

The composition according to the invention also comprises one or more alkaline agent (s) and / or one or more amino derivative (s) of alkoxysilane.

The alkaline agent (s) can be chosen from:

- water-soluble mineral alkaline agents such as

- hydroxides of alkali or alkaline earth metals, preferably lithium, magnesium, calcium, sodium, potassium buffered with one or more amino acids such as glycine, - carbonates, bicarbonates or hydrogen carbonates, carbonates buffered with bicarbonate to obtain a pH <12.0,

- phosphates of alkali or alkaline earth metals such as lithium, calcium, sodium or potassium,

- ammonia,

- alkanolamines such as mono-, di- and triethanolamines, mono-, di- and tri- (hydroxymethyl) aminomethane as well as their derivatives,

- basic amino acids,

- alkaline polyamino acids or alkaline polyamino acids, such as polylysines, polyarginines,

- polyamines such as polyethyleneimines (PEI), polyvinylamines, the compounds of formula (A) below:

Formula (A) in which W is a (Ci-Ce) alkylene group such as propylene optionally substituted by a hydroxy, amino group or a C1-C4 alkyl radical; R _x , R _y , R _z and R _t , identical or different, represent an atom

hydrogen, a C1-C4 alkyl or C1-C4 hydroxyalkyl radical.

As an example of amines of formula (A), mention may be made of 1, 3

diaminopropane, 1, 3 diamino 2 propanol, spermine, spermidine.

By alkanolamine is meant an organic amine comprising a primary, secondary or tertiary amine function, and one or more alkyl groups, linear or branched, C Cs bearing one or more hydroxyl radicals.

Particularly suitable for carrying out the invention are the organic amines chosen from alkanolamines such as mono-, di- or tri-alkanolamines, comprising one to three hydroxyalkyl radicals, which may or may not be C1-C4.

Mention may be made, among compounds of this type, of monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine,

diisopropanolamine, N, N-dimethylethanolamine, aminopropanol, 1-amino-propanol, 2-amino-2-methyl-1-propanol, triisopropanol-amine, 2-amino-2-methyl-1, 3 -propanediol, 3-amino-1, 2-propanediol, 3-dimethylamino-1, 2- propanediol, tris-hydroxymethylamino-methane, aminobutanol, aminopentanol, aminohexanol, preferably 2-amino-2-methyl-1-propanol.

More particularly, the amino acids which can be used are of natural or synthetic origin, in their L, D or racemic form and comprise at least one acid function chosen more particularly from the acid functions

carboxylic, sulfonic, phosphonic or phosphoric.

As amino acids which can be used in the present invention, mention may in particular be made of basic amino acids comprising an additional amine function optionally included in a cycle or in a ureido function.

Such basic amino acids are preferably chosen from those corresponding to the following formula (B), as well as their salts

R-CH ₂ -CH (NH ₂ ) -C (0) -0H (B)

Formula (B) in which R represents a group chosen from: imidazolyl, preferably 5-imidazolyl; - (CH ₂ ) ₃ -NH ₂ ; - (CH ₂ ) ₂ -NH ₂ ; - (CH ₂ ) ₂ N (H) -C (O) -NH ₂ ; and - (CH ₂ ) ₂ -N (H) -C (NH) -NH ₂ .

The compounds corresponding to formula (B) are histidine, lysine, arginine, ornithine, citrulline.

The organic amine can also be chosen from organic amines of heterocyclic type. Mention may in particular be made, in addition to the histidine already mentioned in the amino acids, pyridine, piperidine, imidazole, triazole, tetrazole, benzimidazole.

By “poly” amines or “poly” amino acids is meant alkaline agents comprising at least two amino or amino acid groups linked to the same molecule, in particular these are polymers whose backbone comprises or is substituted by one or more than one amino group or amino acid group.

The organic amine can also be chosen from the amino acid dipeptides. As amino acid dipeptides which can be used in the present invention, mention may in particular be made of carnosine, anserine and whale.

The organic amine can also be chosen from compounds comprising a guanidine function. As amines of this type which can be used in the present invention, there may be mentioned in addition to the arginine already mentioned as amino acid, creatine, creatinine, 1, 1-dimethylguanidine, 1, 1 -diethylguanidine, glycocyamine, metformin, agmatine, n-amidinoalanine, 3-guanidino- acid propionic acid, 4-guanidinobutyric acid and 2 - ([[amino (imino) methyl] amino)] ethane-1-sulfonic acid.

Mention may be made, as hybrid compounds, of the salts of the amines mentioned above with acids such as carbonic acid, hydrochloric acid.

One can in particular use guanidine carbonate or monoethanolamine hydrochloride.

Preferably, the alkaline agent (s) are chosen from water-soluble inorganic alkaline agents, alkanolamines, basic amino acids, organic amines, preferably organic amines.

Preferably, the alkaline agent (s) are chosen from the hydroxides of alkali or alkaline earth metals, preferably lithium, magnesium, calcium, sodium, potassium buffered with one or more amino acids such as glycine, carbonates, bicarbonates or hydrogen carbonates, carbonates buffered with bicarbonate to obtain a pH <12.0, phosphates of alkali or alkaline earth metals such as lithium, calcium, sodium or potassium, monoethanolamine (MEA), l aminopropanol, 1-amino-propanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1, 3-propanediol, aminobutanol, aminopentanol, aminohexanol, arginine and guanidine.

The amino derivative (s) of alkoxysilane can be chosen from the compounds corresponding to formula (C) below and / or their oligomers and / or their hydrolysis products:

RiSi (OR ₂ ) _z (R ₃ ) _x (OH) _y (C)

formula (II) in which:

Ri is a linear or branched C1-C6 hydrocarbon chain,

saturated or unsaturated, cyclic or acyclic substituted by a group chosen from groups:

- amine NH ₂ or NHR (R = alkyl Ci-C ₂ o, in particular C1-C6 alkyl optionally substituted by a radical containing a silicon atom, C3-C40 or aromatic C6-C30),

- an aryl or aryloxy group substituted and / or interrupted by at least one amino group or by at least one C1-C4 aminoalkyl group;

Ri can be interrupted by a heteroatom (O, S, NH) or a carbonyl group (CO). R ₂ and R _{3, which are} identical or different, represent an alkyl group, linear or branched, comprising from 1 to 6 carbon atoms,

• y denotes an integer ranging from 0 to 3, and

• z denotes an integer ranging from 0 to 3, and

• x denotes an integer ranging from 0 to 2,

with z + x + y = 3.

The term “oligomer” means the polymerization products of the compounds of formula (C) comprising from 2 to 10 silicon atoms.

Preferably, R ₂ represents an alkyl group comprising from 1 to 4 carbon atoms, better still a linear alkyl group comprising from 1 to 4 carbon atoms, and preferably the ethyl group.

Preferably, R ₃ represents an alkyl group comprising from 1 to 4 carbon atoms, better still a linear alkyl group comprising from 1 to 4 carbon atoms, and preferably methyl or ethyl groups.

Preferably Ri is an acyclic chain.

Preferably, the compound of formula (C) only has one silicon atom in its structure.

Preferably, Ri represents an alkyl group, and even more

preferably a linear alkyl group comprising from 1 to 6 carbon atoms or a C ₁ -C ₆ aminoalkyl group.

Preferably z varies from 1 to 3. Even more preferably z is equal to 3.

Preferably R 1 is a saturated or unsaturated, linear or branched C1-C6 hydrocarbon chain substituted with an NH 2 or NHR amine group (R = C1-C20 alkyl, especially C1-C6, C3-C40 cycloalkyl or C6-C30).

Preferably, the first composition comprises at least one compound of formula (C) chosen from 3-aminopropyltriethoxysilane (APTES), 3-aminoethyltriethoxysilane (AETES), 3-aminopropylmethyldiethoxysilane, N- (2-aminoethyl) -3- aminopropyltriethoxysilane, 3- (m-aminophenoxy) propyltrimethoxysilane, p-aminophenyltrimethoxysilane, N- (2-aminoethylaminomethyl) phenethyltrimethoxysilane, better among 3-aminopropyltriethoxysilane (APTES), 3-aminoethylmethyl N- (2-aminoethyl) -3-aminopropyltriethoxysilane or their oligomers and / or their hydrolysis products. According to a particularly preferred embodiment, the composition comprises 3-aminopropyl triethoxysilane (APTES) or its oligomers and / or its hydrolysis products.

According to the invention, the alkaline agent (s) and / or the amino derivative (s) of alkoxysilane used (s) is (are) in the composition in a content ranging from 0.01 and 10% by weight, preferably between 0.02 and 5%, by weight relative to the total weight of the composition.

The pH of the composition according to the invention is greater than or equal to 7.

Preferably, the composition of the invention has a pH ranging from 7.0 to 12.0, preferably from 7.5 to 11, better still 8 to 10, even more preferably from 8 to 9.

Preferably, the pH of the composition is stable, that is to say that it remains basic, namely greater than or equal to 7, over time. Preferably, the pH of the composition remains basic for a storage period of at least 4 weeks, or even 8 weeks.

The composition can comprise a cosmetically acceptable medium.

The cosmetically acceptable medium which can be used in the compositions of the invention may comprise a solvent chosen from water, the solvents

organic, and one of their mixtures.

The organic solvents can be chosen from alcohols, polyols, polyol ethers and their mixtures, the alcohols being preferably chosen from lower C1-C6 alkanols, and preferably chosen from ethanol, propanol and isopropanol , the polyols preferably being chosen from propylene glycol, hexylene glycol, glycerin, and pentanediol.

Preferably, the solvent (s) represent (s) 0.1% to 99% of the total weight of the composition.

Preferably, the composition is aqueous.

According to this variant, the amount of water can vary from 5 to 98% by weight, better from 15% by weight to 95% by weight, better still from 25 to 90% by weight and even more preferably from 30 to 90% by weight. weight relative to the total weight of the composition.

The composition according to the invention may also contain additives usually used in cosmetics, such as anionic, cationic, amphoteric or nonionic surfactants, thickening agents, bodies grease, fixing or conditioning polymers, preserving agents, perfumes, dyes, pigments, oxidizing agents, agents

anti-dandruff, hair loss agents, disulfide bond breaking agents, as well as most of the usual cosmetic agents.

These additives can be present in the composition according to the invention in an amount ranging from 0 to 20% by weight relative to the total weight of the

composition.

Those skilled in the art will take care to choose these possible additives and their amounts so that they do not harm the properties of the compositions of the present invention.

The process of the invention comprises, after step a) of applying the composition, a step b) of irradiating the composition on the keratin materials to crosslink the polymer.

This irradiation may consist of illumination with ambient light or with an artificial light source, of the composition applied to keratin materials.

Ambient or artificial light can emit visible and / or UV radiation. Preferably, it emits at least a proportion of radiation in the UV, for example a proportion of UV of at least 2% of the total irradiance of ambient light.

According to a particular embodiment, the exposure comprises, or even consists of, illumination in ambient light of the surface of said layer, in particular for a period of at least 1 minute.

The duration of exposure to ambient light can range more particularly from 10 seconds to 30 minutes, in particular from 2 to 15 minutes.

According to another particular embodiment, the exposure comprises, or even consists of, illumination with an artificial light source from the surface of said layer.

The duration of exposure to said artificial light can range from 1 second to 20 minutes, in particular from 1 second to 1 minute.

The crosslinking can be done in natural or artificial light, for example using lighting with a lamp, a flash, a laser, LEDs, for example in the form of an array of LEDs. The artificial light source can emit radiation in the visible range and / or radiation in the UV.

The light emitted may or may not be monochromatic. The wavelength of the emitted light is preferably centered on 365 nm, in particular between 100 nm and 500 nm, and better still between 200 nm and 420 nm.

Advantageously, the crosslinking is initiated by simple illumination without requiring a photoinitiator.

Preferably, it will be an artificial light source emitting an energy of between 0.5 and 5W / cm ² , the exposure times being adapted accordingly.

Crosslinking can occur with a reduced light intensity, the lighting system can produce this light intensity of, for example, between 500 mJ / cm ² and 10 J / cm ² .

The dual characteristic of the absence of photoinitiator and of relatively low light intensity is particularly advantageous since it makes it possible to limit the harmful effects of aggressive initiators or of prolonged exposure to intense light, in particular in the UV wavelengths. .

A person skilled in the art will be able to adapt the characteristics of the illumination, in particular in terms of duration of exposure and wavelengths of the radiation, with regard to the nature of the photocrosslinkable polymer (s). ) (A) implemented.

According to a preferred embodiment, the composition is applied to keratin fibers such as the hair.

According to this embodiment, the composition can be applied to wet or dry keratin fibers, clean or not. The keratin fibers are preferably dried after application of the composition and before irradiation.

One can also include in the process, before or

after step b) of irradiation, pause at room temperature, or under heat, or under red light.

The following example illustrates the invention without however limiting its scope. Unless otherwise indicated, the quantities are given in mass percentages. Example

The following compositions were produced from the ingredients, the contents of which are indicated in the table below (% in g of active material).

[Table 1]

* polymer of the partially saponified polyvinylacetate type and carrying stilbazolium groups, adsorbed on polyvinylacetate particles

** PVA-SbQ-Propional obtained according to the process described above.

Compositions are obtained which have a stable pH over time, which allows the stability of the polymer.

Homogeneous and persistent sheathing on the hair was obtained.

The same type of results are obtained for PVA-SbQs with phenyl groups.

Claims

1. Composition comprising:

- At least one photocrosslinkable polymer comprising at least one group during photodimerisable;

- one or more alkaline agents and / or amino derivative (s) of alkoxysilane, the alkaline agent (s) and / or amino derivative (s) of alkoxysilane being present (s) ) in the composition in a content ranging from 0.01 to 10% by weight relative to the total weight of the composition,

the pH of the composition being greater than or equal to 7.

2. Composition according to claim 1, characterized in that the photodimerizable group (s) is (are) chosen from monovalent radicals of formulas (I) and (II) below:

as well as their geometric isomers,

formulas (I) and (II) in which:

- Y and Z independently denote each other a nitrogen atom or a C (R) group with R representing a hydrogen atom or a (CrC4) alkyl group such as methyl;

A represents a bond or a divalent group chosen from the radicals (Cr Cs) alkylene, arylene, heteroarylene, cycloalkylene, heterocycloalkylene,

(thio) carbonyls, (C2-Cs) alkenylenes and combinations thereof;

- B represents a monovalent group chosen from (Ci-Cs) alkyl radicals, aryl radicals, optionally cationic heteroaryl, cycloalkyl, optionally cationic heterocycloalkyl, (thio) carbonyls, (C2-Cs) alkenyls and their

combinations;

- X represents a divalent group chosen from (C2-Cs) alkylene radicals, arylene, heteroarylene, cycloalkylene, heterocycloalkylene, (thio) carbonyls, (C2-C ₈ ) alkenylenes and combinations thereof;

- p represents an integer inclusive between 1 and 5, in particular between 1 and 3, preferably p is 1; represents the bond which connects the part of the monovalent radical to the rest of the molecule;

and

each of the groups mentioned possibly being substituted by one or more halogen atoms or groups chosen from (Ci-Ce) alkyl, hydroxy, amino, (di) (Ci-C ₆ ) alkylamino, phenyl, carboxy groups , (Ci-Ce) alkoxy,

(Ci-C ₆ ) alkoxy (thio) carbonyls, hydrogen (thio) -carbonyls, sulfonato R-0-S (0) ₂ - or RS (0) ₂ -0-, amide RR'NC (O) - or RC (0) -N (R ') - or acyl RC (O) -, ammonium RR'R ”N ⁺ - with R, R', and R”, identical or different, representing a hydrogen atom or a group ( CrC4) alkyl.

3. Composition according to Claim 2, characterized in that the photodimerizable group (s) is (are) chosen from monovalent radicals of the following compounds:

- Stilbene,

- Styrylpyridinium (stilbazolium) of formula and their geometric isomers:

Or

- R ¹ and R ³ , identical or different, represent a halogen atom or a (Ci-Ce) alkyl group; or then two contiguous R ¹ or R ^{3 groups} form together with the carbon atoms which carry it a group benzo;

- R ² represents the hydrogen atom, a (Ci-Ce) alkyl group optionally substituted by one or more halogen atoms such as chlorine or hydroxy, preferably R ² represents a (Ci-Ce) alkyl group such that methyl, ethyl, propyl;

- q and r, represent an integer inclusive between 0 and 4; and

- Q, represents an anionic counter ion preferably chosen from halide ions such as chlorides, bromides, iodides, perchlorates, tetrafluoroborates, methylsulfate, phosphates, sulfates, methanesulfonates, p-toluenesulfonate; represents the bond which connects the part of the monovalent radical to the rest of the molecule, it being understood that the group for Â2 can be linked to the rest of the molecule via R ² ;

preferably bond ¹ is on the phenyl in the para position of the styryl group on Ai or linked to the rest of the molecule via R ² on A2; preferably the styryl group of Ai and A2 is found in para of the pyridinium group;

- styrylazolium of formula and their geometric isomers:

or

- A represents a sulfur atom, an oxygen atom, or an NR ² or C (R ² ) 2 group; and Q, r, q, R ¹ , R ² , and R ³ being as defined above,

preferably the bond is on the phenyl in the para position from the stryryl group,

- styrylpyrazine,

- chalcone,

- (thio) cinnamate and (thio) cinnamamide,

- maleimide,

- (thio) coumarin,

- thymine,

- uracil,

- butadiene

- anthracene,

- pyridone,

- pyrrolizinone,

- acridizinium salts,

- furanone,

- phenylbenzoxazole, and

their derivatives.

4. Composition according to any one of the preceding claims, characterized in that the photocrosslinkable polymer has a natural or synthetic backbone chosen from polysaccharides, poly (vinyl) polymers and polydiorganosiloxanes, preferably from poly (vinyl acetate) ), preferably partially saponified.

5. Composition according to any one of the preceding claims, characterized in that the polymer (s) comprising at least one photodimerizable group is a polymer which is soluble or dispersed in the composition.

6. Composition according to any one of the preceding claims, characterized in that the polymer comprising at least one photodimerizable group is in the form of particles, preferably dispersed particles.

7. Composition according to claim 6, characterized in that the particles are particles of polyvinyl alcohol.

8. Composition according to any one of the preceding claims, characterized in that the photocrosslinkable polymer comprises at least one group during hydrophobic.

9. Composition according to the preceding claim, characterized in that the hydrophobic group is chosen from: - a (C1-C30) alkyl group, saturated or unsaturated, optionally substituted and / or interrupted by one or more heteroatoms,

- an alkenyl group,

an aryl group such as phenyl, pyridyl, furyl, Indoyl, benzofuryl. thiophenyl, imizadoyl, oxazoyl, thiazoyl, pyrazinyl, pyrimidinyl;

- a fluorinated group such as a fluorinated carbon group such as -CF3, -CHF2, -OCF3, - SCF ₃ , CF ₃ C (0) -,

a silicone group such as -SiR _a R _b R _c such as -Si (CH3) 3, polydimethylsiloxane- PDMS, -Si (OR) 3, PDMS a, w diaminopropyl, PDMS a, w dihydroxyalkyl,

PDMS a, w dicarboxyalkyl, with R _a , R _b and R _c , identical or different, representing a group (C Cs) alkyl optionally interrupted and / or terminated by one or more non-contiguous heteroatoms such as O, or S; and R representing a (Ci-Ce) alkyl group;

preferably from a (C2-C22) alkyl group, more preferably from a (C3-C16) alkyl group.

10. Composition according to any one of the preceding claims, characterized in that the polymer comprising at least one photodimerizable group represents 0.01 to 25%, preferably 0.1 to 20%, and better still 1 to 15% of the total weight of the composition.

1 1. Composition according to any one of the preceding claims, characterized in that the alkaline agent is chosen from ammonia, alkaline water-soluble alkaline agents such as hydroxides of alkali or alkaline-earth metals such as sodium or postassium , carbonates, phosphates of alkali or alkaline earth metals such as sodium or post potassium, alkanolamines such as mono-, di- and triethanolamines, mono-, di- and tri- (hydroxymethyl) aminomethane as well as their derivatives , basic amino acids, alkaline polyamino acids, such as polylysines, polyarginines, polyamines such as polyethyleneimines (PEI), polyvinylamines, the compounds of formula (A) below:

Formula (A) in which W is a (Ci-Ce) alkylene group such as propylene optionally substituted by a hydroxy, amino group or an alkyl radical in C1-C4; R _x, R _y , R _z , R _t , identical or different, represent a hydrogen atom, a C1-C4 alkyl or C1-C4 hydroxyalkyl radical.

12. Composition according to any one of the preceding claims, characterized in that the alkaline agent is chosen from water-soluble mineral alkaline agents, alkanolamines, basic amino acids, organic amines, preferably organic amines.

13. Composition according to any one of the preceding claims, characterized in that the alkaline agent (s) are chosen from hydroxides of alkali or alkaline earth metals, preferably lithium, magnesium, calcium, sodium, potassium buffered with one or more amino acids such as glycine, carbonates, bicarbonates or hydrogen carbonates, carbonates buffered with bicarbonate to obtain a pH <12.0, phosphates of alkali or alkaline earth metals such as lithium, calcium, sodium or potassium, monoethanolamine (MEA), aminopropanol, 1-amino-propanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1, 3-propanediol, aminobutanol, aminopentanol, aminohexanol, arginine and guanidine.

14. Composition according to any one of the preceding claims, characterized in that it comprises one or more amino derivatives of alkoxysilane corresponding to the following formula (C) and / or their oligomers:

RiSi (OR ₂ ) _z (R ₃ ) _x (OH) _y (C)

formula (C) in which:

Ri is a C1-C6 hydrocarbon chain, linear or branched, saturated or unsaturated, cyclic or acyclic substituted by a group chosen from groups:

- NH2 or NHR amine (R = C1-C20 alkyl, in particular C1-C6 optionally substituted by a radical containing a silicon atom, C3-C40 cycloalkyl OR C6-C30 aromatic),

- an aryl or aryloxy group substituted and / or interrupted by at least one amino group or by at least one C1-C4 aminoalkyl group;

Ri can be interrupted by a heteroatom (O, S, N H) or a carbonyl group (CO),

- R ₂ and R 3, which are identical or different, represent an alkyl group, linear or branched, comprising from 1 to 6 carbon atoms,

- y denotes an integer ranging from 0 to 3, and

- z denotes an integer ranging from 0 to 3, and - x denotes an integer ranging from 0 to 2,

with z + x + y = 3.

15. Composition according to any one of the preceding claims, characterized in that it comprises at least one compound chosen from 3-aminopropyltriethoxysilane (APTES), 3-aminoethyltriethoxysilane (AETES), 3-aminopropylmethyldiethoxysilane, N- ( 2-aminoethyl) -3-aminopropyltriethoxysilane, 3- (m-aminophenoxy) propyltrimethoxysilane, p-aminophenyltrimethoxysilane, N- (2-aminoethylaminomethyl) phenethyltrimethoxysilane, better among 3-aminopropyltriethoxysilane ETAethyl) (amino acid) ), 3-aminopropylmethyldiethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane or their oligomers and / or their hydrolysis products.

16. Composition according to any one of the preceding claims, characterized in that it comprises at least one compound chosen from 3-aminopropyl triethoxysilane and its oligomers and / or its hydrolysis products.

17. Composition according to any one of the preceding claims, characterized in that the alkaline agent (s) and / or amino derivative (s) of alkoxysilane is (are) in the composition. a content ranging from 0.01 to 10% by weight, preferably between 0.02 and 5% by weight relative to the total weight of the composition.

18. Composition according to any one of the preceding claims, characterized in that the pH ranges from 7.5 to 11, better still 8 to 10, even more preferably from 8 to 9.

19. Process for treating keratin materials, preferably keratin fibers, comprising the following steps:

- Application to keratin materials of a composition according to any one of the preceding claims;

- Irradiation of said composition on keratin materials to crosslink the polymer.

20. A method according to the preceding claim characterized in that it comprises, prior to the irradiation step and after the application step, drying of the keratin materials.

21. Method according to any one of claims 19 or 20, characterized in that it comprises, before or after step (b) of irradiation, a pause at room temperature, or under heat, or under red light.

22. Method according to one of claims 19 to 21, characterized in that the irradiation is an irradiation with radiation in the UVA or in the visible range, and preferably radiation in the UVA.