WO2020157292A1

WO2020157292A1 - Cosmetic composition comprising active agents for combating hair loss, thickening polymers and anionic polysaccharides, and treatment process

Info

Publication number: WO2020157292A1
Application number: PCT/EP2020/052460
Authority: WO
Inventors: Laurence Richet; Marion CRUVEILHIER
Original assignee: L'oreal
Priority date: 2019-01-31
Filing date: 2020-01-31
Publication date: 2020-08-06
Also published as: FR3092248A1; FR3092248B1

Abstract

The present invention relates to a cosmetic composition, in particular a hair composition, comprising agents for combating hair loss, anionic polysaccharides and thickening polymers. The invention also relates to a cosmetic process for treating the hair using said composition, in particular for giving the hair body and volume, while preventing or delaying the loss of hair density and/or hair loss.

Description

DESCRIPTION

Title: Cosmetic composition comprising active agents for combating hair loss, thickening polymers and anionic polysaccharides, and treatment pro- cess

The present invention relates to a cosmetic composition, in particular a hair compo sition, comprising the combination of an active agent for combating hair loss, of a thickening polymer and of an anionic polysaccharide. The invention also relates to a cosmetic process for treating keratin fibers using said composition.

The growth of the hair and its renewal are mainly determined by the activity of the hair follicles and their matrix environment. Their activity is cyclical and essentially comprises three phases, namely the anagenic phase, the catagenic phase and the telogenic phase.

The anagenic phase (active or growth phase), which lasts several years and during which the hairs lengthen, is followed by a very short and transient catagenic phase which lasts a few weeks, and then by a telogenic phase or resting phase which lasts a few months. At the end of the resting period, the hairs fall out and another cycle begins again. The head of hair is thus undergoing constant renewal and, of the ap proximately 150 000 hairs which make up a head of hair, approximately 10% are at rest and will be replaced in the months to come. The natural loss of the hair can be estimated, on average, at a few hundred hairs per day for a normal physiological state. This constant physical renewal process undergoes a natural change during the course of aging: the hairs become finer and their cycles shorter.

In addition, various causes may bring about substantial temporary or definitive hair loss. Hair loss, in particular alopecia, is essentially due to disruptions in hair renewal. These disruptions lead in a first step to acceleration of the frequency of the cycles at the expense of the quality of the hairs, and then of their quantity. Progressive miniaturization of the bulbs takes place, in conjunction with isolation of these bulbs by gradual thickening of the perifollicular collagen matrix and also of the outer con nective sheath. Revascularization around the hair follicle is thus made more difficult cycle after cycle. The hairs regress and become miniaturized until they are no more than an unpigmented down, and this phenomenon leads to gradual thinning of the head of hair. The number and mean diameter of the hair follicles that constitute the head of hair are affected. Certain areas are preferentially affected, especially the temporal or frontal lobes in men, and diffuse alopecia of the crown is observed in women. The term "alopecia" also covers an entire family of hair follicle complaints of which the final consequence is partial or general definitive hair loss.

It is known, furthermore, that certain factors, such as hormonal imbalance, physio logical stress or malnutrition, can accentuate the phenomenon. In addition, loss or impairment of the hair can be in connection with seasonal phenomena.

Loss of hair density and/or hair loss are often experienced as distressing by persons thereby affected, especially when they are still young.

Pharmaceutical or cosmetic active agents have been proposed for delaying the pro cesses of loss of hair density and/or excessive hair loss; however, these active agents must generally be used for several weeks, or even several months, in order to obtain an optimum effect; with this solution, it is not possible to obtain an imme diate effect.

In addition, even in the case of an effective treatment, the head of hair visually lacks body and volume. This problem is all the greater in the case of fine hair.

Thus, there is a need to provide compositions which make it possible to efficiently prevent and/or treat loss of hair density (long-term effect), while at the same time providing better cosmetic properties, in particular by giving the head of hair body and volume, as soon as said compositions are applied, thus making it possible to obtain an immediate effect in terms of providing density, mass, rigidity, coating at the root of the hair strand, so as to result in a feeling of greater hair density.

The applicant has found, surprisingly, that the combination according to the inven tion, of an agent for combating hair loss with an anionic polysaccharide and an ad ditional thickening polymer, makes it possible to achieve these objectives.

One subject of the invention is thus a cosmetic composition, in particular a hair com position, comprising:

- one or more agents for combating hair loss,

- one or more anionic polysaccharides, and

- one or more thickening polymers, other than the anionic polysaccharides.

The composition according to the invention makes it possible to obtain improved effects on the head of hair, in particular regarding the hair density, the hair diameter, the provision of body (rigidity) and/or of volume to the head of hair, while at the same time giving the head of hair a pleasant feel, in particular a clean and smooth feel, and a shiny appearance.

The head of hair appears to be more voluminous, in particular in the case of fine hair.

Other characteristics and advantages of the invention will emerge more clearly on reading the description and the examples that follow.

In the text hereinbelow, and unless otherwise indicated, the limits of a range of val ues are included in that range, notably in the expressions "between" and "ranging from ... to ...", these expressions having equivalent meaning and therefore being interchangeable.

Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more".

1/ Agent for combating hair loss

The cosmetic composition according to the invention thus comprises one or more agents for combating hair loss.

The term“agent for combating hair loss” is intended to mean any compound which promotes hair growth and/or an increase in density of said hair, and/or which limits hair loss.

The agents for combating hair loss can advantageously be chosen from the follow ing compounds:

- 2,4-diamino-6-piperidinopyrimidine 3-N-oxide and/or an organic or mineral acid salt thereof and/or a hydrate thereof,

- 2,4-diaminopyrimidine 3-N-oxide and/or an organic or mineral acid salt thereof and/or a hydrate thereof, and

- pyridinedicarboxylic acid esters and salts thereof,

and also mixtures thereof.

2,4-Diamino-6-piperidinopyrimidine 3-N-oxide (or Minoxidil) corresponds to the for mula below:

2,4-Diaminopyrimidine 3-N-oxide (or aminexil) corresponds to the formula below:

Among the organic or mineral acid salts of these compounds that can be used, mention may particularly made of the hydrochlorides, sulfates, citrates and acetates. As hydrate, mention may particularly made of the monohydrate.

Preferably, the non-salified compound in monohydrate form is used.

The pyridinedicarboxylic acid esters correspond to formula (I) below: wherein Ri and R₂ represent, independently of one another, a hydrogen atom, a saturated or unsaturated, linear or branched C₁-C₁₈ aliphatic hydrocarbon-based radical (in particular alkyl); or a C₆-C₁₈ aryl radical; said aliphatic or aryl hydrocarbon- based radicals optionally being substituted with one or more groups chosen from OH, NH₂, -OR, -OCOR and -NHR with R representing a C₁-C₁₈ alkyl group; it being understood that at least one of the Ri and R₂ groups is other than a hydrogen atom.

Preferably, the COOR₁ and COOR₂ substituents are respectively in the 2 and 3 po sitions, or in the 2 and 4 positions of the pyridine ring. Preferably, they are in the 2 and 4 positions.

Preferentially, the compounds correspond to formula (la):

wherein Ri and R₂ represent, independently of one another, a hydrogen atom, a saturated or unsaturated, linear or branched C₁-C₁₈ aliphatic hydrocarbon-based radical (in particular alkyl); or a C₆-C₁₈ aryl radical; said aliphatic or aryl hydrocarbon- based radicals optionally being substituted with one or more groups selected from OH, NH₂, -OR, -OCOR and -NHR with R representing a C₁-C₁₈ alkyl group; at least one of the Ri and R₂ groups being other than a hydrogen atom.

Preferably, in the formulae (I) and (la), the C₁-C₁₈ aliphatic hydrocarbon-based rad ical, in particular alkyl radical, is a C₁-C₁₀, in particular C₁-C6, aliphatic hydrocarbon- based radical, in particular alkyl radical, such as methyl, ethyl, tert-butyl, isopropyl or hexyl. Said aliphatic hydrocarbon-based radical can also comprise at least one carbon-carbon double bond or triple bond, such as, for example, -CH=CH₂, -CH₂- CH=CH-CH₃ and -CH₂-CºCH.

The aryl radical can represent the phenyl or naphthyl radical.

In particular, in the formulae (I) and (la), Ri and R₂ represent, independently of one another, a hydrogen atom or a saturated, linear or branched, C₁-C₁₈, better still Ci- C₁₀, indeed even C₁-C6, aliphatic hydrocarbon-based radical, in particular alkyl rad ical, which is optionally substituted with an alkoxy or acyloxy group (OR or OCOR with R denoting a C₁-C₁₈ alkyl radical), at least one of the Ri and R₂ groups being other than a hydrogen atom.

Preferably, Ri and R2 are identical.

Preferentially, Ri and R2 are identical and represent a saturated linear C₁-C₁₈, pref- erably C₁-C₁₀ and better still C₁-C6 alkyl radical and very particularly an ethyl radical.

Mention may in particular be made of the following compounds of formula (I):

- dimethyl 2,4-pyridinedicarboxylate,

- dimethyl 2,3-pyridinedicarboxylate,

- diethyl 2,4-pyridinedicarboxylate,

- diethyl 2,3-pyridinedicarboxylate,

- diethyl 2,5-pyridinedicarboxylate,

- dimethyl 2,5-pyridinedicarboxylate,

- diisopropyl 2,4-pyridinedicarboxylate,

- di(acetyloxymethyl) 2,4-pyridinedicarboxylate (derivative of formula (I) such that

Ri and R2 represent -CH2-O-COCH3).

Salts of the compounds of formula (I) is intended to mean, according to the inven tion, the organic or inorganic salts of a compound of formula (I), these salts being physiologically acceptable. Mention may be made, as inorganic salts, of the sodium or potassium salts and also the zinc (Zn²⁺), calcium (Ca²⁺), copper (Cu²⁺), iron (Fe²⁺), strontium (Sr²⁺), magnesium (Mg²⁺) or manganese (Mn²⁺) salts; the hydrox ides, the carbonates and the chlorides. Mention may be made, as organic salts, of the triethanolamine, monoethanolamine, diethanolamine, hexadecylamine, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine and tris(hydroxymethyl)amino- methane salts.

Mention may also be made, as agents for combating hair loss that can be used, of the O-acylated derivatives obtained by partial or total esterification of vitamin F by glucose, nicotinic acid esters, menthol and derivatives thereof, and in particular menthoxypropanediol, vitamins such as vitamin D, niacinamide (3-pyridinecarbox- amide), nicotinamide (vitamin B3), vitamin B12 analogs, panthenol, vitamin B8, bio tin (vitamin FI). Preferably, the composition according to the invention comprises one or more agents for combating hair loss chosen from 2,4-diamino-6-piperidinopyrimidine 3-N- oxide, in particular monohydrate, 2,4-diaminopyrimidine 3-N-oxide, in particular monohydrate, and diethyl pyridine-2, 4-dicarboxylate; and also mixtures thereof. Even more preferentially, the composition according to the invention comprises 2,4- diaminopyrimidine 3-N-oxide, in particular monohydrate.

Preferably, the cosmetic composition according to the invention comprises one or more agents for combating hair loss in a total amount ranging from 0.001 % to 20% by weight, preferably from 0.01 % to 15% by weight, in particular from 0.1 to 10% by weight, even better still from 0.5% to 9% by weight, or even from 1 % to 8% by weight, relative to the total weight of the cosmetic composition.

In one preferred embodiment, the cosmetic composition according to the invention comprises the 2,4-diaminopyrimidine 3-N-oxide, in particular monohydrate, in an amount ranging from 0.001 % to 20% by weight, preferably from 0.01 % to 15% by weight, in particular from 0.1 % to 10% by weight, even better still from 0.5% to 9% by weight, or even from 1 % to 8% by weight, relative to the total weight of the cos metic composition.

21 Anionic polysaccharide (ii)

The composition according to the invention comprises one or more anionic polysac charides.

The anionic polysaccharides according to the invention comprise one or more ani onic or anionizable groups, and do not comprise any cationic or cationizable group.

Preferably, the anionic polysaccharide is chosen from gums arabic.

Gums arabic are exudates of sap from trees of the acacia family, in particular acacia Senegal. They are anionic polysaccharides that are generally highly branched, con stituted of D-galactose, L-arabinose, L-rhamnose and D-glucuronic acid units. Their INCI name is ACACIA SENEGAL GUM.

Mention may also be made, as anionic polysaccharide that can be used, of:

- ghatti gum (polymer resulting from arabinose, galactose, mannose, xylose and glucuronic acid),

- karaya gum (polymer resulting from galacturonic acid, galactose, rhamnose and glucuronic acid),

- gum tragacanth (polymer of galacturonic acid, galactose, fucose, xylose and arab inose),

- alginates (polymers of mannuronic acid and of glucuronic acid),

- xanthan gum (polymer of glucose, mannose acetate, mannose/pyruvic acid and glucuronic acid),

- gellan gum (polymer of partially acylated glucose, rhamnose and glucuronic acid).

The composition according to the invention preferably comprises the anionic poly saccharide^) in a total content of greater than or equal to 0.5% by weight, in partic ular ranging from 0.5% to 10% by weight, preferably ranging from 1 % to 8% by weight, and preferably ranging from 2% to 5% by weight, relative to the total weight of the composition.

In particular, the composition according to the invention preferably comprises the gum(s) arabic in a total content of greater than or equal to 0.5% by weight, in par ticular ranging from 0.5% to 10% by weight, preferably ranging from 1 % to 8% by weight, and preferably ranging from 2% to 5% by weight, relative to the total weight of the composition.

3/ Additional thickening polymer (iii)

The composition according to the invention also comprises one or more thickening polymers other than the anionic polysaccharides (ii) above.

For the purposes of the present invention, the term "thickening polymer" is intended to mean a polymer which, when introduced at 1 % by weight in an aqueous solution or an aqueous-alcoholic solution containing 30% ethanol, and at pH 7, makes it possible to achieve a viscosity of at least 100 cps (centipoises), in particular of at least 200 cps, preferably of at least 500 cps, measured at 25°C and at a shear rate of 1 s ¹. This viscosity may be measured using a cone/plate viscometer (Haake R600 rheometer or the like).

The thickening polymers according to the invention may be of natural or synthetic origin. They can be chosen from thickening acrylic polymers and thickening poly saccharides other than the anionic polysaccharides above. A mixture of several thickening polymers may also be used.

For the purposes of the present invention, the term "acrylic polymer" is intended to mean a polymer that results from a polymerization reaction using one or more mon omers) of structure:

with R3 denoting a hydrogen atom or a linear or branched C1 -C4 alkyl radical, and R4 denoting a hydrogen atom, a linear or branched C1 -C4 alkyl radical, an N R5R6 radical, or a linear or branched C1 -C30 alkoxy radical, said radicals being optionally substituted with one or more OH radicals and/or a quaternary ammonium radical, R₅ and Re denoting, independently of one another, a hydrogen atom or an optionally oxyalkylenated linear or branched C1 -C30 alkyl radical, optionally comprising a sul fonic group.

Preferably, R₃ denotes a hydrogen atom or a methyl radical.

The acrylic thickening polymers that can be used in the present invention may be chosen from:

(a) (meth)acrylic associative polymers; (b) crosslinked homopolymers of (meth)acrylic acid and crosslinked copolymers of (meth)acrylic acid and of C₁-C6 alkyl acrylate;

(c) nonionic homopolymers and copolymers containing ethylenically unsaturated monomers of ester and/or amide type;

(d) ammonium acrylate homopolymers and copolymers of ammonium acrylate and of acrylamide;

(e) (meth)acrylamido(Ci-C₄)alkylsulfonic acid homopolymers and copolymers;

(f) crosslinked methacryloyloxy(Ci-C₄)alkyltri(Ci-C₄)alkylammonium homopolymers and copolymers.

According to the invention, the term“associative thickening polymer” is intended to mean an amphiphilic thickening polymer comprising both hydrophilic units and hy drophobic units, in particular comprising at least one C₈-C₃₀ fatty chain and at least one hydrophilic unit.

The (meth)acrylic associative thickening polymers according to the invention may be nonionic, anionic, cationic or amphoteric.

Preferably, the nonionic associative thickening polymers according to the invention are chosen from:

- copolymers of C₁-C₆ alkyl (meth)acrylates and of amphiphilic monomers compris ing at least one fatty chain (for example oxyethylenated (C₈-C₂₂)alkyl acrylates), for instance the oxyethylenated methyl methacrylate/stearyl acrylate copolymer sold by the company Goldschmidt under the name Antil 208; and

- copolymers of hydrophilic (meth)acrylates and of hydrophobic monomers compris ing at least one fatty chain (for example (C₈-C₂₂)alkyl (meth)acrylates), for instance polyethylene glycol methacrylate/lauryl methacrylate copolymer.

The anionic associative thickening polymers according to the invention can be cho sen from those comprising at least one hydrophilic unit of unsaturated olefinic car boxylic acid type, and at least one hydrophobic unit of the type such as a (C₁₀-C₃₀) alkyl ester of an unsaturated carboxylic acid.

They are preferably chosen from those (i) for which the hydrophilic unit of unsatu rated olefinic carboxylic acid type corresponds to the monomer of formula (I) below:

wherein R¹ denotes H, CH₃ or C₂H₅, i.e. acrylic acid, methacrylic acid or ethacrylic acid units, and (ii) for which the hydrophobic unit of the type such as a (Cio-C₃o)alkyl ester of unsaturated carboxylic acid corresponds to the monomer of formula (II) be low: wherein R¹ denotes H or Chh or C2H5, preferably H or Chh; and R² denotes a C10- C30, preferably C12-C22, alkyl radical. (C10-C30) Alkyl esters of unsaturated carboxylic acids in accordance with the inven tion comprise, for example, lauryl acrylate, stearyl acrylate, decyl acrylate, isodecyl acrylate and dodecyl acrylate, and the corresponding methacrylates, lauryl methac rylate, stearyl methacrylate, decyl methacrylate, isodecyl methacrylate and dodecyl methacrylate.

The anionic associative thickening polymers according to the present invention may more particularly denote polymers formed from a mixture of monomers comprising:

(i) either acrylic acid and one or more esters of formula (III) below:

wherein R¹ denotes H or CH3, R² denotes an alkyl radical containing from 12 to 22 carbon atoms, and optionally a crosslinking agent, such as, for example, those con stituted of from 60% to 95% by weight of acrylic acid (hydrophilic unit), 4% to 40% by weight of C10-C30 alkyl acrylate (hydrophobic unit), and 0% to 6% by weight of crosslinking polymerizable monomer, or those constituted of 96% to 98% by weight of acrylic acid, 1 % to 4% by weight of C10-C30 alkyl acrylate and 0.1 % to 0.6% by weight of crosslinking polymerizable monomer,

(ii) or essentially acrylic acid and lauryl methacrylate, such as the product formed from 66% by weight of acrylic acid and 34% by weight of lauryl methacrylate. As crosslinking agent, mention may in particular be made of polyallyl ethers, such as, in particular, polyallyl sucrose and polyallyl pentaerythritol.

Among said above polymers, those most particularly preferred are the products sold by the company Goodrich under the trade names Pemulen TR1 , Pemulen TR2 and Carbopol 1382, and even more preferentially Pemulen TR1 , and the product sold by the company SEPC under the name Coatex SX.

Among the anionic amphiphilic polymers comprising fatty chains, mention may also be made of copolymers comprising among their monomers an a,b-monoethyleni- cally unsaturated carboxylic acid and an ester of an a,b-monoethylenically unsatu- rated carboxylic acid and of an oxyalkylenated fatty alcohol.

Preferentially, these compounds also comprise as monomer an ester of an a,b-mo- noethylenically unsaturated carboxylic acid and of a C1 -C4 alcohol.

By way of examples, mention may be made of Aculyn 22® sold by the company Rohm and Haas, which is an oxyalkylenated methacrylic acid/ethyl acrylate/stearyl methacrylate terpolymer (INCI name Acrylates/Steareth-20 Methacrylate Copoly mer), or else Aculyn 28® sold by Rohm and Haas, which is an oxyalkylenated methacrylic acid/ethyl acrylate/behenyl methacrylate terpolymer (INCI name Acry- lates/Beheneth-25 Methacrylate Copolymer), likewise the Novethix L-10 Polymer sold by Lubrizol.

As anionic amphiphilic polymers comprising fatty chains, mention may also be made of the methacrylic acid/methyl acrylate/ethoxylated alcohol dimethyl-meta-isopro- penylbenzylisocyanate copolymer in particular sold under the name Viscophobe DB 1000 by the company Amerchol.

Mention may also be made, as anionic amphiphilic polymers comprising fatty chains, of those comprising at least one acrylic monomer having sulfonic group(s), in free or partially or completely neutralized form, and comprising at least one hy- drophobic portion.

The hydrophobic portion present in the polymers of the invention preferably com prises from 8 to 22 carbon atoms, preferentially from 8 to 18 carbon atoms and more particularly from 12 to 18 carbon atoms.

Preferentially, the sulfonic polymers in accordance with the invention are partially or totally neutralized with a mineral base (sodium hydroxide, potassium hydroxide or aqueous ammonia) or an organic base such as mono-, di- or triethanolamine, an aminomethylpropanediol, N-methylglucamine, basic amino acids, for instance argi nine and lysine, and mixtures of these compounds.

The sulfonic amphiphilic polymers in accordance with the invention generally have a number-average molecular weight (Mn) ranging from 1000 to 20 000 000 g/mol, preferably ranging from 20 000 to 5 000 000 and preferentially from 100 000 to 1 500 000 g/mol.

The sulfonic amphiphilic polymers according to the invention may or may not be crosslinked. Crosslinked amphiphilic polymers are preferably chosen.

When they are crosslinked, the crosslinking agents can be chosen from polyolefini- cally unsaturated compounds commonly used for the crosslinking of polymers ob tained by radical polymerization. Mention may be made, for example, of divinylben- zene, diallyl ether, dipropylene glycol diallyl ether, polyglycol diallyl ethers, triethy- lene glycol divinyl ether, hydroquinone diallyl ether, ethylene glycol diacry- latedi(meth)acrylate or tetraethylene glycol di(meth)acrylate, trimethylolpropane tri acrylate, methylenebisacrylamide, methylenebismethacrylamide, triallylamine, trial- lyl cyanurate, diallyl maleate, tetraallylethylenediamine, tetraallyloxyethane, trime thylolpropane diallyl ether, allyl (meth)acrylate, allyl ethers of alcohols of the sugar series, or other allyl or vinyl ethers of polyfunctional alcohols, and also allyl esters of phosphoric and/or vinylphosphonic acid derivatives, or mixtures of these com pounds. Methylenebisacrylamide, allyl methacrylate or trimethylolpropane triacrylate (TMPTA) will more particularly be used. The degree of crosslinking generally ranges from 0.01 mol% to 10 mol% and more particularly from 0.2 mol% to 2 mol% relative to the polymer.

The acrylic monomers having sulfonic group(s) are chosen in particular from (meth)acrylamido(Ci-C22)alkylsulfonic acids and N-(Ci-C22)al- kyl(meth)acrylamido(Ci-C22)alkylsulfonic acids, such as undecylacrylami- domethanesulfonic acid, and also their partially or completely neutralized forms. (Meth)acrylamido(Ci-C22)alkylsulfonic acids, for instance acrylamidomethanesul- fonic acid, acrylamidoethanesulfonic acid, acrylamidopropanesulfonic acid, 2- acrylamido-2-methylpropanesulfonic acid, methacrylamido-2-methylpropanesul- fonic acid, 2-acrylamido-n-butanesulfonic acid, 2-acrylamido-2,4,4-trimethylpen- tanesulfonic acid, 2-methacrylamidododecylsulfonic acid or 2-acrylamido-2,6-dime- thyl-3-heptanesulfonic acid, and also partially or totally neutralized forms thereof, will more preferentially be used.

2-Acrylamido-2-methylpropanesulfonic acid (AMPS), and also partially or totally neutralized forms thereof, will more particularly be used.

The amphiphilic polymers in accordance with the invention may be chosen in par ticular from random amphiphilic AMPS polymers modified by reaction with a C6-C22 n-monoalkylamine or di-n-alkylamine, and such as those described in patent appli cation WO 00/31154 (which form an integral part of the content of the description). These polymers may also contain other ethylenically unsaturated hydrophilic mon omers chosen, for example, from (meth)acrylic acids, b-substituted alkyl derivatives thereof or esters thereof obtained with monoalcohols or mono- or polyalkylene gly- cols, (meth)acrylamides, vinylpyrrolidone, maleic anhydride, itaconic acid and ma leic acid, or mixtures of these compounds.

The preferred polymers of the invention are selected from amphiphilic AMPS copol ymers and of at least one ethylenically unsaturated hydrophobic monomer compris ing at least one hydrophobic portion containing from 8 to 50 carbon atoms, more preferably from 8 to 22 carbon atoms, more preferably still from 8 to 18 carbon atoms and more particularly 12 to 18 carbon atoms.

These same copolymers may also contain one or more ethylenically unsaturated monomers not comprising a fatty chain, such as (meth)acrylic acids, b-substituted alkyl derivatives thereof or esters thereof obtained with monoalcohols or mono- or polyalkylene glycols, (meth)acrylamides, vinylpyrrolidone, maleic anhydride, ita conic acid and maleic acid, or mixtures of these compounds.

The ethylenically unsaturated hydrophobic monomers of these particular copoly mers are preferably chosen from the acrylates or acrylamides of formula (IV) below: wherein Ri and R₃, which may be identical or different, denote a hydrogen atom or a linear or branched C1-C6 alkyl radical (preferably methyl); Y denotes 0 or NH; R2 denotes a hydrocarbon-based radical containing at least from 8 to 50 carbon atoms, preferentially from 8 to 22 carbon atoms, better still from 6 to 18 carbon atoms and more particularly from 12 to 18 carbon atoms; x denotes a number of moles of al- kylene oxide and ranges from 0 to 100.

The radical R2 is preferably selected from linear C6-C18 alkyl radicals (for example n-hexyl, n-octyl, n-decyl, n-hexadecyl or n-dodecyl radicals); branched or cyclic Ob- Ci8 alkyl radicals (for example cyclododecane (C12) or adamantane (C10)); C6-C18 alkylperfluoro radicals (for example the group of formula -(CH2)2-(CF2)9-CF3); the cholesteryl (C27) radical or a cholesterol ester residue, such as the cholesteryl oxy- hexanoate group; or polycyclic aromatic groups, such as naphthalene or pyrene. Preference is more particularly given, among these radicals, to linear alkyl radicals and more particularly to the n-dodecyl radical.

According to one particularly preferred form of the invention, the monomer of for mula (IV) comprises at least one alkylene oxide unit (x > 1 ) and preferably a polyox- yalkylenated chain. The polyoxyalkylenated chain preferentially is constituted of eth ylene oxide units and/or propylene oxide units and even more particularly is consti tuted of ethylene oxide units. The number of oxyalkylenated units generally ranges from 3 to 100, preferentially from 3 to 50 and even more preferentially from 7 to 25. Mention may be made, among these polymers, of:

- crosslinked or non-crosslinked, neutralized or non-neutralized copolymers, includ ing from 15% to 60% by weight of AMPS units and from 40% to 85% by weight of (C₈-Ci₆)alkyl(meth)acrylamide or (C₈-Ci₆)alkyl(meth)acrylate units relative to the polymer, such as those described in patent application EP-A750 899;

- terpolymers including from 10 mol% to 90 mol% of acrylamide units, from 0.1 mol% to 10 mol% of AMPS units and from 5 mol% to 80 mol% of n-(C₆-Ci₈)alkylacrylamide units, such as those described in patent US-5 089 578.

Mention may also be made of copolymers of totally neutralized AMPS and of do- decyl methacrylate, and also crosslinked and non-crosslinked copolymers of AMPS and of n-dodecylmethacrylamide, such as those described in the Morishima articles mentioned above.

Mention will be made more particularly of the copolymers constituted of 2- acrylamido-2-methylpropanesulfonic acid (AMPS) units of formula (V) below:

wherein X⁺ is a proton, an alkali metal cation, an alkaline earth metal cation or the ammonium ion,

and of units of formula (VI) below:

wherein x denotes an integer from 3 to 100, preferably from 5 to 80 and preferentially from 7 to 25; Ri has the same meaning as that indicated above in formula (IV), and R4 denotes a linear or branched C6-C22 and preferentially C10-C22 alkyl.

The polymers that are particularly preferred are those for which x = 25, Ri denotes methyl and R4 represents n-dodecyl; the polymers for which X⁺ denotes sodium or ammonium are more particularly preferred.

The cationic associative thickening polymers according to the present invention can be chosen from polyacrylates comprising amine side groups.

The polyacrylates containing quaternized or non-quaternized amine side groups contain, for example, hydrophobic groups of the type of steareth-20 (stearyl alcohol comprising 20 mol of ethylene oxide) or (Cio-C₃o)alkyl PEG-20 itaconate.

Mention may be made, as examples of polyacrylates having aminated side chains, of the polymers 8781 -124B or 9492-103 or Structure Plus from the company Na tional Starch.

The amphoteric associative thickening polymers according to the invention may be chosen from methacrylamidopropyltrimethylammonium chloride/acrylic acid/Cio-C3o alkyl methacrylate copolymers, the alkyl radical preferably being a stearyl radical.

(b) Mention may be made, among the crosslinked (meth)acrylic acid homopolymers, of the products sold under the names Carbopol 980, 981 , 954, 2984 and 5984 by the company Goodrich or the products sold under the names Synthalen M and Syn- thalen K by the company 3 VSA.

Mention may be made, among the crosslinked copolymers of (meth)acrylic acid and of Ci-Ce alkyl acrylate, of the product sold under the name Viscoatex 538C by the company Coatex, which is a crosslinked copolymer of methacrylic acid and of ethyl acrylate as an aqueous dispersion containing 38% active material, or the product sold under the name Aculyn 33 by the company Rohm & Haas, which is a cross linked copolymer of acrylic acid and of ethyl acrylate as an aqueous dispersion con taining 28% active material. Mention may more particularly be made of the cross- linked methacrylic acid/ethyl acrylate copolymer in the form of an aqueous 30% dis persion manufactured and sold under the name Carbopol Aqua SF-1 by the com pany Noveon.

(c) Mention may be made, among the nonionic homopolymers or copolymers con- taining ethylenically unsaturated monomers of ester and/or amide type, of the prod ucts sold under the names Cyanamer P250 by the company Cytec (polyacrylamide); PMMA MBX-8C by the company US Cosmetics (methyl methacrylate/ethylene gly col dimethacrylate copolymer); Acryloid B66 by the company Rohm & Haas (butyl methacrylate/methyl methacrylate copolymer); and BPA 500 by the company Kobo (polymethyl methacrylate).

(d) Mention may be made, among the ammonium acrylate homopolymers, of the product sold under the name Microsap PAS 5193 by the company Hoechst.

Among the copolymers of ammonium acrylate and of acrylamide that may be men- tioned is the product sold under the name Bozepol C Nouveau or the product PAS 5193 sold by the company Hoechst.

(e) The (meth)acrylamido(Ci-C4)alkyl sulfonic acid homopolymers or copolymers are preferably crosslinked. More particularly, they are partially or completely neu- tralized. These are water-soluble or water-swellable polymers.

Mention may in particular be made, among these polymers, of:

- polyacrylamidomethanesulfonic acid,

- polyacrylamidoethanesulfonic acid,

- polyacrylamidopropanesulfonic acid,

- poly-(2-acrylamido-2-methylpropanesulfonic acid),

- poly-(2-methylacrylamido-2-methylpropanesulfonic acid),

- poly-(2-acrylamido-n-butanesulfonic acid). Polymers of this type and in particular crosslinked and partially or completely neu tralized poly(2-acrylamido-2-methylpropanesulfonic acids) are known, described and prepared in Patent Application DE-196 25 810. They are generally characterized in that they comprise, randomly distributed:

- from 90% to 99.9% by weight of units of formula (A):

wherein X⁺ denotes a cation or a mixture of cations, including H⁺, and

- from 0.01 % to 10% by weight of at least one crosslinking unit containing at least two olefinic double bonds, the weight proportions being defined relative to the total weight of the polymer.

Preferably, the crosslinked and neutralized poly(2-acrylamido-2-methylpropanesul- fonic acid) comprises from 98% to 99.5% by weight of units of formula (A) and from 0.5% to 2% by weight of crosslinking units.

Preferably, X⁺ represents a cation or a mixture of cations chosen in particular from a proton, an alkali metal cation, a cation equivalent to that of an alkaline-earth metal, or the ammonium ion.

Preferably, the crosslinking units having at least two olefinic double bonds are cho sen from dipropylene glycol diallyl ether, polyglycol diallyl ethers, triethylene glycol divinyl ether, hydroquinone diallyl ether, tetraallyloxyethane or other polyfunctional alcohol allyl or vinyl ethers, tetraethylene glycol diacrylate, triallylamine, trime- thylolpropane diallyl ether, methylenebisacrylamide or divinylbenzene.

The crosslinking units bearing at least two olefinic double bonds are more particu larly chosen from those corresponding to the general formula (B) below:

wherein Ri denotes a hydrogen atom or a C1-C4 alkyl and more particularly methyl (trimethylolpropane triacrylate).

The crosslinked and partially or completely neutralized poly(2-acrylamido-2- methylpropanesulfonic acids) are generally known under the names“Ammonium polyacrylamido-2-methylpropanesulfonate” or else“Ammonium polyacryldimethyl- tauramide” (INCI name).

A product that is particularly preferred according to the invention is the one sold by the company Clariant under the trade name Hostacerin AMPS; this is a crosslinked poly(2-acrylamido-2-methylpropanesulfonic acid) partially neutralized with aqueous ammonia. (f) Mention may be made, among the crosslinked homopolymers or copolymers of methacryloyloxy(Ci-C4)alkyltri(Ci-C4)alkylammonium, of the polymers obtained by homopolymerization of dimethylaminoethyl methacrylate quaternized with methyl chloride, or by copolymerization of acrylamide with dimethylaminoethyl methacry late quaternized with methyl chloride, the homopolymerization or copolymerization being followed by crosslinking with an olefinically unsaturated compound, in partic ular methylenebisacrylamide. Mention may more particularly be made of the cross linked acrylamide/methacryloyloxyethyltrimethylammonium chloride copolymer (in particular 20/80 by weight), in particular in the form of a dispersion containing 50% by weight of said copolymer in mineral oil. This dispersion is in particular sold under the name Salcare® SC 92 by the company Ciba. Mention may also be made of the crosslinked homopolymer of methacryloyloxyethyltrimethylammonium chloride, in particular in the form of a dispersion comprising approximately 50% by weight of the homopolymer in mineral oil or in a liquid ester. These dispersions are sold under the names Salcare^® SC 95 and Salcare^® SC 96 by the company Ciba.

Among the acrylic thickening polymers that can be used in the present invention, use will preferably be made of one or more acrylic thickening polymers of the family b), more preferentially chosen from crosslinked homopolymers of (meth)acrylic acid. As indicated above, the thickening polymers according to the invention may be cho sen from thickening polysaccharides other than the anionic polysaccharides above. The thickening polysaccharides according to the invention may be of natural or syn thetic origin. They may be nonionic, amphoteric or cationic.

The base units of the polysaccharides of the invention may be mono- or disaccha- rides. The units that may be included in the composition of the polysaccharides of the invention are preferably derived from the following sugars: glucose, galactose, arabinose, rhamnose, mannose, xylose, fucose, fructose, anhydrogalactose.

Mention may in particular be made, as thickening polysaccharides that can be em- ployed, of the following polymers, and also derivatives thereof:

- guar gum (polymer of mannose and galactose),

- locust bean gum (polymer of mannose and galactose),

- fenugreek gum (polymer of mannose and galactose),

- tamarind gum (polymer of galactose, xylose and glucose),

- konjac gum (polymer of glucose and mannose),

- scleroglucan gum (glucose polymer),

- cellulose (glucose polymer), - starch (glucose polymer),

- inulin (polymer of fructose and glucose).

These polymers may be physically or chemically modified. Mention may in particular be made, as physical treatment, of the temperature. Chemical treatments that may be mentioned include esterification, etherification, amidation and oxidation reac tions. These treatments make it possible to result in polymers which can be nonionic, cationic or amphoteric.

The nonionic guar gums that may be used according to the invention may be modi- fied with C1-C6 hydroxyalkyl groups. Mention may be made, among the hydroxyalkyl groups, of the hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxybutyl groups. These guar gums are well known in the prior art and may be prepared, for example, by reacting corresponding alkene oxides, for instance, propylene oxides, with the guar gum so as to obtain a guar gum modified with hydroxypropyl groups. The degree of hydroxyalkylation preferably varies from 0.4 to 1.2 and corresponds to the number of alkylene oxide molecules consumed by the number of free hydroxyl functions present on the guar gum. Such nonionic guar gums optionally modified with hydroxyalkyl groups are for example sold under the trade names Jaguar HP8, Jaguar HP60 and Jaguar HP120 by the company Rhodia Chimie.

The guar gums modified with cationic groups which can more particularly be used according to the invention are guar gums comprising trialkylammonium cationic groups. Preferably, from 2% to 30% of the number of the hydroxyl functional groups of these guar gums carry trialkylammonium cationic groups. More preferably still, from 5% to 20% of the number of the hydroxyl functional groups of these guar gums are branched with trialkylammonium cationic groups. Among these trialkylammo nium groups, mention may most particularly be made of the trimethylammonium and triethylammonium groups. More preferably still, these groups represent from 5% to 20% by weight relative to the total weight of the modified guar gum. According to the invention, use may be made of guar gums modified with 2,3-epoxypropyltrime- thylammonium chloride. These guar gums modified with cationic groups are prod ucts already known per se and are, for example, described in Patents US 3 589 578 and US 4 0131 307. Such products are sold especially under the trade names Jag uar C13 S, Jaguar C 15 and Jaguar C 17 by the company Rhodia Chimie. Use may be made, as modified locust bean gum, of the cationic locust bean gum containing hydroxypropyltrimonium groups, such as Catinal CLB 200 provided by the company Toho.

The starch molecules used in the present invention can originate from any plant starch source, in particular cereals and tubers; more particularly, they can be starches from maize, rice, cassava, barley, potato, wheat, sorghum, pea, oat or tap ioca. Use may also be made of the starch hydrolysates mentioned above or other starch derivatives. The starch is preferably derived from potato. The starches can be chemically or physically modified, in particular by one or more of the following reactions: pregelatinization, oxidation, crosslinking, esterification, etherification, amidation or heat treatments.

More particularly, these reactions may be performed in the following manner:

- pregelatinization by splitting the starch granules (for example drying and cooking in a drying drum);

- oxidation with strong oxidizing agents, resulting in the introduction of carboxyl groups into the starch molecule and in the depolymerization of the starch molecule (for example by treating an aqueous starch solution with sodium hypochlorite);

- crosslinking with functional agents capable of reacting with the hydroxyl groups of the starch molecules, which will thus be bonded together (for example with glyceryl and/or phosphate groups);

- esterification in alkaline medium for the grafting of functional groups, especially Ci- C₆ acyl (acetyl), C1-C6 hydroxyalkyl (hydroxyethyl or hydroxypropyl), carboxymethyl or octenylsuccinic.

Among the starch derivatives, mention may in particular be made of dextrins.

According to the invention, use may also be made of amphoteric starches compris- ing one or more anionic groups and one or more cationic groups. The anionic and cationic groups may be bonded to the same reactive site of the starch molecule or to different reactive sites; they are preferably bonded to the same reactive site. The anionic groups can be of carboxylic, phosphate or sulfate type, preferably of carbox ylic type. The cationic groups may be of primary, secondary, tertiary or quaternary amine type.

The amphoteric starches are in particular chosen from the compounds having the following formulae:

wherein:

St-0 represents a starch molecule, R, which may be identical or different, represents a hydrogen atom or a methyl rad ical;

R’, which may be identical or different, represents a hydrogen atom, a methyl radical or a -COOH group;

n is an integer equal to 2 or 3,

M, which may be identical or different, denotes a hydrogen atom, an alkali metal or alkaline earth metal, such as Na, K, Li or NFU, a quaternary ammonium or an organic amine,

R" represents a hydrogen atom or a C1-C18 alkyl radical.

Use is in particular made of the starches of formula (lla) or (Ilia); and preferably starches modified with 2-chloroethylaminodipropionic acid, that is to say the starches of formula (lla) or (Ilia) wherein R, R’, R” and M represent a hydrogen atom and n is equal to 2. The preferred amphoteric starch is a starch chloroethylamidodi- propionate.

The celluloses and cellulose derivatives can be cationic, amphoteric or nonionic. Among these derivatives, mention may be made of cellulose ethers, cellulose esters and cellulose ester ethers.

Among the nonionic cellulose ethers that may be mentioned are alkylcelluloses such as methylcelluloses and ethylcelluloses (for example Ethocel Standard 100 Pre mium from Dow Chemical); hydroxyalkylcelluloses such as hydroxymethylcelluloses and hydroxyethylcelluloses (for example Natrosol 250 HHR sold by Aqualon) and hydroxypropylcelluloses (for example Klucel EF from Aqualon); mixed hydroxyalkyl- alkylcelluloses such as hydroxypropylmethylcelluloses (for example Methocel E4M from Dow Chemical), hydroxyethylmethylcelluloses, hydroxyethylethylcelluloses (for example Bermocoll E 481 FQ from Akzo Nobel) and hydroxybutylmethylcellu- loses.

Among the cationic cellulose ethers, mention may be made of crosslinked or non- crosslinked quaternized hydroxyethylcelluloses. The quaternizing agent can in par- ticular be diallyldimethylammonium chloride (for example Celquat L200 from Na tional Starch). Mention may be made, as other cationic cellulose ether, of hydroxy- ethylcellulose hydroxypropyltrimethylammonium (for example Ucare polymer JR 400 from Amerchol). The thickening polysaccharides may be associative. Mention may in particular be made of celluloses or derivatives thereof, modified with groups comprising at least one fatty chain, such as alkyl, arylalkyl or alkylaryl groups or mixtures thereof where the alkyl groups are C8-C22 groups; nonionic alkyl hydroxyethylcelluloses, such as the products Natrosol Plus Grade 330 CS and Polysurf 67 (Cie alkyl) sold by the company Aqualon; quaternized alkyl hydroxyethylcelluloses (cationic), such as the products Quatrisoft LM 200, Quatrisoft LM-X 529-18-A, Quatrisoft LM-X 529-18-B (C12 alkyl) and Quatrisoft LM-X 529-8 (C18 alkyl) sold by the company Amerchol, the products Crodacel QM, Crodacel QL (C12 alkyl) and Crodacel QS (C18 alkyl) sold by the company Croda, and the product Softcat SL 100 sold by the company Amerchol; nonionic nonoxynyl hydroxyethylcelluloses, such as the product Amercell HM-1500 sold by the company Amerchol; or nonionic alkylcelluloses, such as the product Bermocoll EHM 100 sold by the company Berol Nobel.

As associative thickening polysaccharides derived from guar, mention may be made of hydroxypropyl guars modified with a fatty chain, such as the product Esaflor HM 22 (modified with a C22 alkyl chain) sold by the company Lamberti; the product Miracare XC 95-3 (modified with a Cu alkyl chain) and the product RE 205-146 (modified with a C20 alkyl chain) sold by Rhodia Chimie.

Among the thickening polysaccharides other than the anionic polysaccharides (ii), use will preferably be made of a nonionic polysaccharide, better still a nonionic pol ysaccharide chosen from celluloses and derivatives thereof.

Preferably, the thickening polymers according to the invention are chosen from, alone or as a mixture:

- nonionic polysaccharides, in particular chosen from celluloses and derivatives thereof;

- crosslinked homopolymers of (meth)acrylic acid and crosslinked copolymers of

(meth)acrylic acid and of a C1-C6 alkyl, in particular ethyl, acrylate.

Preference is most particularly given to nonionic polysaccharides, in particular nonionic celluloses, and derivatives thereof; even better still nonionic cellulose ethers, such as (Ci-C4)alkylcelluloses such as methylcelluloses and ethylcelluloses; (Ci-C4)hydroxyalkylcelluloses such as hydroxymethylcelluloses, les hydroxyethyl celluloses and hydroxypropylcelluloses.

The composition according to the invention may comprise the thickening polymer(s) (iii) in a total amount ranging from 0.01 % to 10% by weight, in particular from 0.05% to 5% by weight, preferentially from 0.1 % to 3% by weight, or even from 0.2% to 2% by weight, relative to the total weight of the composition.

In particular, the composition according to the invention may comprise one or more nonionic polysaccharides in a total amount ranging from 0.01 % to 10% by weight, in particular from 0.05% to 5% by weight, preferentially from 0.1 % to 3% by weight, or even from 0.2% to 2% by weight, relative to the total weight of the composition.

4/ Other constituents

The composition according to the invention may comprise a cosmetically acceptable medium, that is to say a medium compatible with topical application to keratin fibers, in particular the hair.

Preferably, said cosmetic composition is a composition for the hair, which may be a rinse-out or a leave-in composition, preferably a leave-in composition.

It is preferably in the form of a shampoo, a gel, a hair lotion or a conditioning care product. The composition according to the invention preferably comprises water and/or one or more organic solvents that may be selected from linear or branched C1-C6 mon oalcohols, such as ethanol, isopropanol, tert-butanol or n-butanol; polyols, such as glycerol, propylene glycol, hexylene glycol (or 2-methyl-2,4-pentanediol) and poly ethylene glycols; polyol ethers, such as dipropylene glycol monomethyl ether; and mixtures thereof.

Preferably, the cosmetic composition comprises water in a content ranging from 30% to 98% by weight, in particular from 40% to 95% by weight, better still from 50% to 90% by weight, relative to the total weight of the composition.

Preferably, the cosmetic composition comprises the organic solvent(s), when they are present, in a content ranging from 0.05% to 60%, preferably from 0.5% to 50% and even better still from 1 % to 40% by weight, relative to the total weight of the cosmetic composition.

In one particular embodiment of the invention, the composition comprises 60% to 80% by weight of water and 15-25% by weight of ethanol.

The cosmetic composition according to the invention may further comprise at least one standard cosmetic ingredient, in particular chosen from plant, mineral, animal or synthetic oils; liquid fatty alcohols; liquid fatty esters; solid fatty substances and in particular waxes, solid fatty esters, solid alcohols; anionic, cationic, amphoteric and nonionic surfactants; sunscreens; moisturizers; antidandruff agents; antioxi dants; pearlescent agents and opacifiers; plasticizers or coalescence agents; hy droxy acids; preservatives; sequestrants (EDTA and salts thereof); colorants. The composition may of course comprise several cosmetic ingredients featured in the above list. Those skilled in the art will take care to select the ingredients making up the composition, and also the amounts thereof, such that the advantageous proper ties of the composition according to the invention are not, or are not substantially, adversely affected by the envisaged addition.

Preferably, the composition does not comprise (less than 0.1 % by weight, preferably 0%) any silicone compound, i.e. a compound comprising at least one silicon atom.

The composition is then said to be“silicone free”.

The invention also relates to a cosmetic process for treating keratin fibers, in partic ular a hair treatment process, wherein a cosmetic composition as defined above is applied on said fibers.

Said process is more particularly intended to give the hair body and/or volume and/or to prevent and/or delay the loss of hair density and/or hair loss. In particular, said process makes it possible to give the hair body and/or volume, while preventing and/or delaying the loss of hair density and/or hair loss.

The step of applying the composition may optionally be followed by a step of leaving the composition on the fibers, and/or by a step of rinsing the fibers, for example with water, and/or by a step of drying the keratin fibers.

Preferably, the application step is not followed by rinsing.

The following examples are given by way of illustration of the present invention. Example 1

The following hair compositions according to the invention were prepared (% by weight of active material AM):

[Table 1 ]

[Table 2]

[Table 3]

Compositions are obtained which, after application to the hair, give them volume and body (rigid coating of the lock); the hair retains a clean (dry coating) and smooth feel, and has a good sheen.

Example 2

The following hair compositions were prepared (% by weight of active material AM): [Table 4]

Locks of natural hair are washed beforehand with a DOP shampoo and rinsed. The composition to be tested is applied to the wet locks, in a proportion of 0.15 g per g of hair, then the locks are dried in an oven at 60°C for 10 minutes.

A panel of 5 experts evaluates blind each of the locks, assigning a score ranging from 0 to 5 (in increments of 0.5); the score 0 signifying“no volume at all”,“no body at all” and the score 5 signifying“very considerable volume”,“very considerable body”.

The overall performance of the composition is the addition of the properties evalu ated.

The properties evaluated are:

- volume: visual evaluation of the overall volume occupied by the lock

- body (presence of a rigidity of the lock): tactile evaluation of the degree of rigidity of the lock: the lock is folded in the palm of the hand in order to eval uate the resistance to folding. The following results are obtained (average of the 5 scores):

[Table 5]

It is noted that only the composition according to the invention makes it possible to obtain a satisfactory overall performance enabling the fiber to be given both good volume and good body (coating).

Example 3

The following hair compositions were prepared (% by weight of active material AM): [Table 6]

A panel of 5 experts evaluates blind each of the locks, with regard to the criteria of volume and provision of body, in the manner described in the previous example.

The following results are obtained (average of the 5 scores):

[Table 7]

Claims

1. A cosmetic composition, in particular a cosmetic hair composition, comprising: - one or more agents for combating hair loss,

- one or more anionic polysaccharides, and

- one or more thickening polymers, other than the anionic polysaccharides.

2. The composition as claimed in claim 1 , wherein the agents for combating hair loss are chosen from the following compounds, alone or as a mixture:

- the pyridinedicarboxylic acid esters of formula (I) and/or salts thereof,

wherein Ri and R₂ represent, independently of one another, a hydrogen atom, a saturated or unsaturated, linear or branched C₁-C₁₈ aliphatic hydrocarbon-based radical (in particular alkyl radical); or a C₆-C₁₈ aryl radical; said aliphatic or aryl hy drocarbon-based radicals optionally being substituted with one or more groups cho sen from OH, NH₂, -OR, -OCOR and -NHR with R representing a C₁-C₁₈ alkyl group; it being understood that at least one of the Ri and R₂ groups is other than a hydro gen atom; preferably Ri and R₂ represent, independently of one another, a hydro- gen atom or a linear or branched, in particular alkyl, saturated C₁-C₁₈, better still Ci- C₁₀ or even O-i-Ob, aliphatic hydrocarbon-based radical, which is optionally substi tuted with an alkoxy or acyloxy group (OR or OCOR with R denoting a C₁-C₁₈ alkyl radical), at least one of the Ri and R₂ groups being other than a hydrogen atom; and better still Ri and R₂ are identical and represent a saturated linear C₁-C₁₈, pref- erably C₁-C₁₀ and even better still C₁-C6 alkyl radical; and very particularly an ethyl radical.

3. The composition as claimed in either of the preceding claims, wherein the agents for combating hair loss are chosen from the following compounds: and the compounds of formula (la)

wherein Ri and R₂ represent, independently of one another, a hydrogen atom, a saturated or unsaturated, linear or branched C₁-C₁₈ aliphatic hydrocarbon-based radical (in particular alkyl radical); or a C₆-C₁₈ aryl radical; said aliphatic or aryl hy drocarbon-based radicals optionally being substituted with one or more groups cho sen from OH, NH₂, -OR, -OCOR and -NHR with R representing a C₁-C₁₈ alkyl group; it being understood that at least one of the Ri and R₂ groups is other than a hydro gen atom; preferably Ri and R₂ represent, independently of one another, a hydro gen atom or a linear or branched, in particular alkyl, saturated C₁-C₁₈, better still Ci- C₁₀ or even O-i-Ob, aliphatic hydrocarbon-based radical, which is optionally substi tuted with an alkoxy or acyloxy group (OR or OCOR with R denoting a C₁-C₁₈ alkyl radical), at least one of the Ri and R₂ groups being other than a hydrogen atom; and better still Ri and R₂ are identical and represent a saturated linear C₁-C₁₈, pref erably C₁-C₁₀ and even better still C₁-C6 alkyl radical; and very particularly an ethyl radical.

4. The composition as claimed in one of the preceding claims, comprising the agent(s) for combating hair loss in a total amount ranging from 0.001 % to 20% by weight, preferably from 0.01 % to 15% by weight, in particular from 0.1 % to 10% by weight, even better still from 0.5% to 9% by weight, or even from 1 % to 8% by weight, relative to the total weight of the cosmetic composition.

5. The composition as claimed in one of the preceding claims, wherein the anionic polysaccharides are chosen from gums arabic.

6. The composition as claimed in one of the preceding claims, comprising the ani onic polysaccharide(s) in a total content of greater than or equal to 0.5% by weight, in particular ranging from 0.5% to 10% by weight, preferably ranging from 1 % to 8% by weight, and preferentially ranging from 2% to 5% by weight, relative to the total weight of the composition.

7. The composition as claimed in one of the preceding claims, wherein the thicken ing polymers are chosen from thickening acrylic polymers and thickening polysac charides other than the anionic polysaccharides above, or mixtures thereof.

8. The composition as claimed in one of the preceding claims, wherein the thicken ing polymers are chosen from:

(a) (meth)acrylic associative polymers;

(b) crosslinked homopolymers of (meth)acrylic acid and crosslinked copolymers of (meth)acrylic acid and of C1-C6 alkyl acrylate;

(e) (meth)acrylamido(Ci-C4)alkylsulfonic acid homopolymers and copolymers;

(f) crosslinked methacryloyloxy(Ci-C4)alkyltri(Ci-C4)alkylammonium homopolymers and copolymers.

(g) the following thickening polysaccharides, and also derivatives thereof: guar gum, locust bean gum, fenugreek gum, tamarin gum, konjac gum; scleroglucan gum, cel lulose, starch, inulin; which are optionally physically or chemically modified.

9. The composition as claimed in one of the preceding claims, wherein the thicken ing polymers are chosen from crosslinked homopolymers of (meth)acrylic acid, crosslinked copolymers of (meth)acrylic acid and of C1-C6 alkyl acrylate, in particular ethyl acrylate; and nonionic polysaccharides, better still chosen from celluloses and derivatives thereof, better still nonionic cellulose ethers, such as (Ci-C4)alkylcellu- loses such as methylcelluloses and ethylcelluloses; hydroxy(Ci-C4)alkylcelluloses such as hydroxymethylcelluloses, hydroxyethylcelluloses and hydroxypropylcellu- loses.

10. The composition as claimed in one of the preceding claims, comprising the thick ening polymer(s) (iii) in a total amount ranging from 0.01 % to 10% by weight, in particular from 0.05% to 5% by weight, preferentially from 0.1 % to 3% by weight, or even from 0.2% to 2% by weight, relative to the total weight of the composition.

11. The composition as claimed in one of the preceding claims, comprising water, preferably in a content ranging from 30% to 98% by weight, in particular from 40% to 95% by weight, better still from 50% to 90% by weight, relative to the total weight of the composition; and/or comprising one or more organic solvents, preferably in a content ranging from 0.05% to 60%, preferably from 0.5% to 50%, and better still from 1 % to 40% by weight, relative to the total weight of the cosmetic composition.

12. The composition as claimed in one of the preceding claims, comprising 60% to 80% by weight of water and 15-25% by weight of ethanol.

13. A cosmetic process for treating keratin fibers, in particular the hair, wherein a cosmetic composition as defined in one of the preceding claims is applied to said fibers, said process being more particularly intended to give the hair body and/or volume and/or to prevent and/or delay the loss of hair density and/or hair loss.

14. The process as claimed in claim 13, wherein the step of applying the composi tion is followed by a step of leaving the composition on the fibers, and/or by a step of rinsing the fibers, for example with water, and/or by a step of drying the keratin fibers; preferably, the application step is not followed by rinsing.