Cosmetic compositions comprising anionic and cationic surfac- tants, i. e. surfactants which are considered to be non-compatible under nor- mal conditions, often show low stability during storage because of precipitati- on and/or phase separation.

Applicants have now discovered that cosmetic compositions comprising at least one adduct formed by at least one anionic surfactant and at least one cationic surfactant of the formula (1) are stable during storage.

According to the present invention there are provided cosmetic compositions comprising a) from 0, 1 % to 70 % by weight of at least one anionic surfactant b) from 0, 05 % to 10 % by weight of at least one cationic surfactant of the formula (1) wherein R'is selected from the group consiting of (C8-C22)-alkyl, (C8-C22)- alkenyl, (C8-C22)-alkylamidopropyl, (C8-C22)-alkenylamidopropyl, (C8-C22)- alkoxy-propyl or (C8-C22)-alkenyloxypropyl R2, R3 and R4 are the same or different and are independently from each other selected from the group consisting of (Cr-C22)-alkyl, preferably (C1-C4)-alkyl, highly preferred CH3 (C1-C22)- alkenyl, preferably (C,-C4)-alkenyl, and groups having the formula -A- n-OH, wherein A is C2H4 and/or C3H6, preferably C2H4 and n is a number from 0 to 20, preferably 0 to 5, highly preferred 0, with the provision that at least one of the radicals R2, R3 and R4is a group having said formula

-A- (AO) n-OH, and X-is an a anion, preferable chloride, bromide, sulphate or metho- sulphate, highly preferred chloride; and c) optionally from 0.1 % to 15 % by weight of one or more nonionic and/or amphoteric surfactants.

Preferably the present compositions comprise from 2 to 50 %, highly preferred from 2 to 10% by weight, of anionic surfactants a) from 0.5 % to 8.0 % highly preferred from 0.5% to 2.5% by weight, of cationic surfac- tants b) of formula (1) and from 0.1 to 5% by weight of nonionic and/or am- photeric surfactants c) Preferred cationic surfactants according to formula (1) are such whe- rein R2, R3 and R4 are the same or different and are independently from each other selected from the group consisting of CH3 and groups of the formula-A- (OA) n-OH, wherein A is C2H4 and/or C3H6, preferably C2H4, n is a number from 0 to 20, preferably 0 to 5, highly preferred 0, with the provision that at least one of radicals R2, R3 and R4 is a group having said formula-A- (AO) n- OH.

Highly preferred as cationic surfactant of the formula (1) is alkyl dimethyl-hydroxyethyl ammonium chloride.

Preferred anionic surfactants are selected from the group consis- ting of alkyl sulfates, alkyl ether sulfates, secondary alkane sulfonates, alpha olefin sulfonates, acyl isocyanates, linear alkylbenzene sulfonates, isethio- nates, and mixtures thereof.

Said alkyl ether sulfates are preferably water-soluble salts or acids of the formula RO (A) mS03M, wherein R is an unsubstituted (Cio-C24)- alkyl or (C10-C24)-hydroxyalkyl radical, preferably a (C12-C20)-alkyl or (C12- C2o)-hydroxyalkyl radical, particularly preferred a (Cr2-C18)-alkyl or a (C12- C, 8)-hydroxyalkyl radical ; A is an ethoxy or propoxy unit; m is a number gre- ater than 0, preferably between 0.5 and 6, particularly preferred between 0.5 and 3; and M is a hydrogen atom or a cation, preferably a metal cation like sodium, potassium, lithium, calcium or magnesium, an ammonium cation a substituted ammonium cation, preferably a methylammonium, di-

methylammonium, trimethylammonium, mono-, di-or triethanolammonium cation, or a quaternary ammonium cation, preferably a tetramethylammonium cation, a dimethylpiperidinium cation or a cation derived from alkylamines like ethylamine, diethylamine, triethylamine.

Particularly preferred alkyl ether sulfates are (C, 2-C18)-alkyl- polyethoxylate (1.0) sulfate, (C12-C18)-alkyl polyethoxylate (2.25) sulfate, (C12- C8)-alkyl polyethoxylate (3.0) sulfate and (C12-C18)-alkyl polyethoxylate (4.0) sulfate Said secondary alkane sulfonates can contain a saturated or un- saturated, alkyl group which can be linear or branched and which can optio- nally be substituted with a hydroxyl group. The sulfo group can be randomly distributed over the entire carbon chain.

Preferred secondary alkane sulfonates contain linear alkyl chains having from 9 to 25 carbon atoms, preferably from 10 to 20 carbon atoms, particularly preferred from 13 to 17 carbon atoms. Preferred cations are so- dium, potassium, ammonium, mono-, di-or triethanolammonium, calcium, magnesium or mixtures thereof. Particularly preffered is sodium.

Said olefin sulphonates preferably contain linear or branched (C8-C22)-alkyl or (C8-C22)-alkenyl groups. Preferred cations are sodium, potas- sium, ammonium, TEA, DEA, MEA, Triethylamine ; magnesium, or mixtures thereof.

Said alkylbenzene sulfonates preferably contain linear alkyl chains having from 9 to 25 carbon atoms, preferably from 10 to 13 carbon atoms. The alkyl group can either be saturated or unsaturated and can be branched or linear. Optionally the alkyl group can be substituted by a hydro- xyl group. Preferred cations are sodium, potassium, ammonium, mono-, di- or triethanolammonium, calcium or magnesium and mixtures thereof.

Said nonionic and amphoteric surfactants are preferably selected from the group consisting of alkyl polyalkylene glycols, alkylaryl polyalkylene glycols, alkyldimethyl amine oxides, dialkyl methyl amine oxides, alkylamido- propyl amine oxides, alkyl glucamides, alkyl polyglycosides, oxalkylated fatty

acids, oxalkylated fatty acid esters, alkyl amines, alkyl amidopropyl betaines, alkyl dimethyl betaines and alkyl amphoacetates or-diacetates. The alkyl groups may be partially or fully replaced by alkenyl groups and may be linear or branched. Said alkyl groups preferably contain 8 to 22 carbon atoms. The polyalkylene glycol groups preferably contain 1 to 20 ethoxy and/or propoxy units.

Highly preferred amphoteric surfactants are cocamidopropyl be- taine, sodium lauroamphoacetate and disodium lauroamphodiacetate.

Suitable co-surfactants are e. g. acyl glutamates, amide ether sulfates, methyl taurides, sarcosynates, Sodium Laureth 13-Carboxylate or mixtures thereof.

The compositions according to the present invention can optio- nally contain oils, emulsifiers, thickeners, natural and synthetic polymers, stabilizers, waxes, fillers, acids, bases, buffers, biological active compounds, vitamines, natural extracts, solubilizers, UV-absorber, perfumes, perfume carriers, pearlescing agents, dyes, bleaching agents and/or other ingredients conventionally used in cosmetic compositions.

The cosmetic compositions can be used widely in personal hygi- ene. Said compositions can be liquids, emulsions, lotions, creams, gels, or solids. If solids they are preferably used in the form of bars. Advantageously the rheology of said compositions can be adjusted over a wide range by va- rying the weight rations of said anionic and cationic surfactants.

Preferably the cosmetic compositions are hair treatment compo- sitions like shampoos, lotions, creams, sprays and lacquers, preferably shampoos, highly preferred shampoos for african-ethnic hair.

Advantageously such hair treatment compositions provide an improved ability to comb the hair. Moreover they allow to reduce or even to eliminate emollient agents and conditioners like silicones, propyleneglycols and esters. When applied to african-ethnic hair such hair treatment composi- tions advantageously provide a positive hair volume decrease.

The invention is illustrated in the following non limiting examples, in which all percentages are on a weight basis unless otherwise.

Example 1-Shampoo Formulation Sodium Lauryl Ether Sulfate (*Genapol LRO) 7.85 Alkyl Dimethyl Hydroxy Ethyl Ammonium Chloride (*Praepagen HY) 0.98 Sodium Laureth 13-Carboxylate (*Sandopan LS-24N) 0.3 Sodium Lauroamphoacetate (*Genagen LAA) 0.87 Perfume qs Preserver qs Water qs NaCI qs Example 2-Shampoo Formulation Alpha Olefin Sulfonate (Hostapur OS) 7.0 Sodium Lauryl Ether Sulfate (*Genapol LRO) 3.0 Sodium Lauroamphoacetate (*Genagen LAA) 4.0 Alkyl Dimethyl Hydroxy Ethyl Ammonium Chloride (*Praepagen HY) 0.5 Perfume qs Preserver qs Water qs NaCI qs (*) commercialized by Cariant SA