TECHNICAL FIELD The present invention relates to novel low skin irritation surfactants and surfactant compositions which are high in foaming properties containing, as an active ingredient, a diamine monoalkyl phosphate salt.

BACKGROUND OF THE INVENTION Soaps, detergents and abrasives have long been used to cleanse the skin on various portions of the body. Anionic surfactants such as alkyl sulfates, polyoxyethylene alkyl sulfates, alkylbenzene sulfon- ates and β-olefin sulfonates have been widely used as the surfactant component for many cleansers. It is known that such anionic surfactants are adsorbed and thereby remain on the skin surface to cause dryness and scaling of the epidermis, or skin chapping and roughness, if they are used continual¬ ly. Thus, skin troubles such as roughness of hands are apt to be caused by the use of detergents. Skin roughness can be a precursor of more severe skin troubles such as eczema. Thus, there is an urgent need to eliminate this disadvantage.

Nonioπic surfactants, on the other hand, cause little or no skin dryness or roughness. However, they do not have the same advantageous properties of foaming and detergency as anionic surfactants. It has, therefore, not been suitable to incorporate nonionic surfactants into cleansing compositions as the primary detergent component.

Phosphoric add esters have been known as anionic surfactants, generally as mono- and diesters, or mixtures thereof. However, in general, their water solubilities and foaming properties are not ver good.

European Patent No. 265 702 published Hay 4, 1988 disclose transparent or semi-transparent cosmetic compositions containing monoalkyl phosphate, water, oil and alcohol for skin treatment. Th oils and alcohols are used to obtain clarity. U.S. Patent 4,573,74 to Mclntosh, issued June 28, 1988 discloses monoamine alkyl phosphate having antimicrobial activity. U.S. Patent 4,290,904 to Poper et al. issued September 22, 1981, U.K. Patent No. 1,513,053, published Jun 7, 1978 and European Patent 023 978, published February 18, 198 disclose cosmetic and toiletry preparations containing alkoxylate

alkylene dlaalnes. U.S. Patent 4,476,043, 4,476,044 and 4,476,045 to O'Lenlck, all Issued October 9, Ϊ984 and U.S. Patent 4,477,372 to O'Lenick, issued October 16, 1984 disclose substantially non-aqueous surfactants containing an organic sulfate, mineral oil and an alkoxyl- ated amine. However, none of these references disclose the use of a diamine alkyl phosphate surfactant.

Monoalkyl phosphate salts have also been disclosed as useful surfactants in U.S. Patent 4,139,485 to Imokawa et al., issued Febru¬ ary 13, 1979. However, these surfactants form turbid aqueous solu- tions unless they contain other solvents (e.g., solubilizing agents). Further, the rheology of these salts limits the variety of formula¬ tions which can be made with aesthetically pleasing characteristics.

It has been discovered that certain novel diamine monoalkyl phosphate salts as well as certain transparent and stable surfactant compositions containing these salts readily enable the preparation of stable non-pressurized, aerated foams. These foams possess good cleansing power and detergency, are mild and non-irritating, and leave little, if any, residual film remaining on the cleansed surface of the skin. These compositions are homogeneous in nature, can be structured to be wet or dry, stable or fastbreaking, and are aesthetically suit¬ able for use in a wide variety of personal care products.

One of the principal purposes of this invention is to describe the preparation of an aqueous skin cleansing composition made from the novel diamine monoalkyl phosphate salts of the present invention which will produce a usable foam from a hand-held, squeezable foam dispens¬ ing device, as well as from an aerosol device and further which will not render the device unusable by, for example, clogging the device.

Another object of this invention is to provide surfactants and foaa- roducing surfactant compositions which produce relatively stable or collapsible foams. A preferred embodiment of this invention is to provide skin cleansing foams of low density.

Another object of this invention is to provide surfactants and foaming compositions with creamy lather, good skin feel and good rinsability and which retains skin elasticity. Another object of this invention is to provide a surfactant and surfactant composition which is mild and non-irritating to skin and eyes and which does not require the use of propellants, thereby avoiding the danger of explosion or corrosion of the container.

Still another object of this invention is to provide a foa producing composition such that if placed in a hand-held, foam dis pensing device having deformable walls, the amount of force require to produce the foam is not excessive (i.e., less than about 15 psi and is readily usable by the average person.

These objectives as well as others apparent to those skilled i the art are obtained with the compounds and compositions describe herein.

SUMMARY OF THE INVENTION This invention comprises diamine monoalkyl phosphate salts havin low irritation effect to human skin of the formula:

OX,

R0--P"0X ₂ 0 wherein R is a hydrophobic group or the condensation product of hydrophobic group with ethylene oxide, preferably R is alkyl alkenyl having an average of from about 10 to 18 carbon atoms, a wherein _λ and X ₂ are independently selected from the group consisti of hydrogen, alkali metal, ammonium, substituted ammonium (e.g. alkoxylated ammonium, al ylammonium, alkoxylated aliphatic amine polyethoxylated amines) and alkylene diamine, provided that at lea one of X, and X _Ϊ is a totally hydroxyalkylatad alky ene diamine.

Also disclosed are compositions comprising these diamine monoalk phosphate salts. Sesqui lkyl phosphate salts are not within the scope of t present invention.

All parts, percentages and ratios used herein are by weight a all measurements are at 25 ^* C unless otherwise indicated. DETAILED DESCRIPTION QF THE INVENTION The surfactant compounds of the present invention are of t formula:

wherein R is a hydrophobic group or the condensation product of hydrophobic group with ethylene oxide, preferably R is alkyl alkenyl having an average of from about 10 to 18 carbon atoms, a wherein ^ and X ₂ are independently selected from the group consisti of hydrogen, alkali metal, ammonium, substituted ammonium (e.g

alkoxylated ammonium, alkylammonium, alkoxylated aliphatic amines, polyethoxylated amines) and alkylene diamine, provided that at least one of X _x and X ₂ is a totally hydroxy al ylatedalkylene diamine.

Monoalkyl phosphate salts in the present invention can be pre- pared, for example, by a known process wherein a long chain aliphatic alcohol (or the condensation product of a long chain aliphatic alcohol with ethylene oxide) is reacted with a phosphatizing agent such as phosphoric anhydride or phosphorus oxychloride. It is recognized that the dialkyl phosphate can be by-produced by this process and which possess poor water-solubility or foaming properties. Such dialkyl phosphates have the formula: ox,

RO-P-OR

II

0 wherein R is a hydrophobic group or the condensation product of a hydrophobic group with ethylene oxide, preferably R is alkyl or alkenyl having an average of from about 10 to 18 carbon atoms, and wherein X ₃ is selected from the group consisting of hydrogen, alkali metal, ammonium, substituted ammonium (e.g., alkoxylated ammonium, alkylammonium, alkoxylated aliphatic amines, polyethoxylated amines) and alkylene diamine. Preferably, R is the condensation product of a hydrophobic group with from about 1 to about 10 moles and preferably from about 1 to about 4 moles of ethylene oxide.

Preferably, the weight ratio of the diamine monoalkyl phosphate salt to the dialkyl phosphate salt is from about 99:1 to about 70:30, respectively, preferably from about 100:0 to about 90:10, most prefer¬ red is a ratio of substantially 100:0. However, unlike monoamine, alkali, or ammonium phosphate salts, these diamine phosphates of the diester are uniquely water-soluble and, therefore, will not interfere as much with the devices and formulations described herein.

The surfactants of the present invention are particularly useful in detergent products which are directly contacted with the skin for a long time such as facial cleansers, shampoos, and solid synthetic detergent toilet bars, because they have a characteristic, excellent foaming power and skin roughness is not caused. The surfactants can also be used as ingredients of dish-washing liquid detergents, powder detergents and dentifrices and are particularly useful compositions where a clear and non-turbid composition is desirable.

The saturated and unsaturated hydrocarbon groups having an average carbon number of 10-18 (R) are straight chain, branched or allcycllc hydrocarbons such as decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups and corresponding olefinically unsaturated groups. Those hydrocarbon groups are contained in the compositions singly or in the form of a combination of several groups. Saturated hydrocarbon groups of an average carbon number of 10 to 14 and unsaturated hydrocarbon groups of an average carbon number of 16 are particularly preferred. Also preferred for use herein are the saturated or unsaturated hydrocarbon groups wherein said hydrocarbon groups possess from about 1 to about 10 units and preferably from about 1 to about 4 units of ethylene oxide per molecule.

The preferred alkali metals for X _x and X ₂ according to the invention, are, for example, lithium, sodium and potassium.

The alkylammonium or substituted alkylammonium for X _t and X ₂ according to the invention, are cations produced from amines used for neutralization of the corresponding phosphoric acids by salt formation after the neutralization step in the process for preparing monoalkyl phosphate salts in the present invention. The corresponding amines are primary, secondary and tertiary amines having alkyl groups of 1 to 4 carbon atoms which can be further substituted, particularly by hydroxyl groups. As the amines, there can be mentioned, for example, d1methylmonoethanolamine, methyldlethanolamine, trimethylamine, triethylamine, d1butylamine, butyldimethylamine, monoethanolamine, diethanolamine, triethanolamine, isopropyldimethylamine and isopropyl- ethanolamine. Preferred amines are monoethanolamine, diethanolamine and triethanolamine. A particularly preferred amine is triethanol¬ amine. Other useful amines include arginine, lysine, mono-, di- or trϋsopropanolamine, N,N-tris(hydroxymethyl)aminomethane, diglycol- amine, glucamine, arainomethylpropanol , and aminomethylpropanediol . Also useful in the present invention are the copolymers derived fro the addition of ethylene oxide and propylene oxide available as Tetronic* and Tetronic R* available from BASF Corporation and th polyethoxylated amines available as the Ethomeen ⁰ series availabl from Armak Corporation.

The alkylene diamine, according to the present invention has the general formula: in which R _lt R ₂ , R ₄ and R _s are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a hydroxylalkyl or dihydroxyalkyl group having 1 to 4 carbon atoms or R ₄ and R ₅ jointly form a saturated 5 or 6 membered heterocyclic ring, which can be substituted by an oxo- or hydroxyalkyl group and R ₃ represents an alkylene or hydroxyalkylene group having 2 to 4 carbon atoms, provided that at least one of R _{1( 2.} R ₃ . R_ ₁ and R ₅ contain at least one hydroxy group.

These compounds are fully disclosed in U.K. Patent 1,513,053, published June 7, 1978.

A particular amine class that 1s useful herein is an N,N-tetrakis (hydroxyalkyl) ethylene diamine having the formula: R R

[H0-CH-CH ₂ ] _n [CH ₂ -CH0H] _n [HO-CH-CH ₂ ] _n [CH ₂ -CHOH3n R R wherein Rx is alkylene having two to four carbon atoms, R is hydrogen or an alkyl group having one to six carbon atoms and n is from one to four. The foregoing diamine preferably has a molecular weight of under about 1700, preferably under about 1200, even more preferably under about 800 and most preferably under about 500. Although other examples will also be given hereinafter, the tetrakis (hydroxyalkyl) ethylene diamine is best exemplified by the compound N,N,N',N'-tetrakis(2-hydroxypropyl)-ethylenediamine, obtain¬ able commercially under the trademark Quadrol or Neutrol TE (both available from BASF Wyandotte Company). Examples of diamine monoalkyl phosphate salts useful in the present invention include, but are not limited to, tetrahydroxypropylethylenediamine monococoylphosphate, tetrahydroxypropylethylenediamine monolaurylphosphate, tetrahydroxypropylethylenediamine (monoethoxylated) monolaurylphosphate, tetrahydroxypropylethylenediamine monoisostearylphosphate, tetrahydroxypropylethylenediamine monostearylphosphate, tetrahydroxypropylethylenediamine (monoethoxylated) monostearylphosphate,

tetrahydroxypropylethylenediamine monomyristylphosphate, tetrahydroxypropylethylenediamine (monoethoxylated) monomyristyl hosphate, tetrahydroxypropylethylenediamine monooleoylphosphate, tetrahydroxypropylethylenediamine monopal iItylphosphate, tetrahydroxypropylethylenediamine (monoethoxylated) monopalmi1ty1phosphate, tetrahydroxypropylethylenediamine monocaprylphosphate, tetrahydroxypropylethylenediamine (monoethoxylated) monocaprylphosphate, tetrahydroxypropylethylenediamine monoundecy1enylphosphate, tetrahydroxypropylethylenediamine monotridecylenylphosphate, tetrahydroxypropylethylenediamine mono(methylmyristyl)phosphate, tetrahydroxypropylethylenediamine mono(1sopropy11 uryl)phosphate, tetrahydroxypropylethylenediamine mono(isodecylneopentyl)phosphate, tetrahydroxypropylethylenediamine monocetylphosphate, and tetrahydroxypropylethylenediamine mono(isopropy1myristyl)phosphate.

COMPOSITIONS The compositions of the present invention comprise: (a) from about 0.1% to about 99% of one or more of a diamin monoalkyl phosphate salt of the present invention; and (b) from about 1.0% to about 99.0% of a detergent carrier. Preferred compositions comprise a mixture of the diamine mono alkyl phosphate salts wherein R is selected from the group consistin of C _X2 to C _l4 alkyl or alkenyl and C _lβ to C _lβ alkyl or alkenyl (or th condensation porduct of these moieties with from about 1 to about 1 moles of ethylene oxide) and wherein said salts are present in a rati of from about 80:20 to about 20:80, preferably from about 60:40 t about 40:60 and most preferably from about 55:45 to about 45:55 respectively.

The compositions of the present invention can be administere topically, i.e., by the direct laying on or spreading of the composi tion on epidermal or epithelial tissue. Such compositions can b formulated as foams, lotions, creams, ointments, solutions, gels o solids. A highly preferred composition contains the monoalkyl phos phate salt in a soap matrix (i.e., liquid and solid). These topica compositions comprise a safe and effective amount, usually from abou 0.1% to about 99%, and preferably from about 1% to about 10%, of th

_ _ 93 monoalkyl phosphate salt. Bar compositions generally contain &ry high levels I.e., above 80%, of the diamine monoalkyl phosphate salt. Generally, the carrier is either organic in nature or a solution or an aqueous emulsion and is capable of having the diamine monoalkyl - phosphate salt dispersed, dissolved or suspended therein. The carrier can include pharmaceutically-acceptable emollients, skin penetration enhancers, coloring agents, fragrances, emulsifiers, thickening agents, and solvents. A more detailed description of such forms follows: 0 1. Lotions.

The lotions can comprise a safe and effective amount of the monoalkyl phosphate salt; from about 0.1% to about 25%, preferably from about 3% to about 15%, of an emollient; the balance being water, a C ₂ or C ₃ alcohol, or a mixture of water and the alcohol. Examples 5 of suitable emollients are as follows:

1. Hydrocarbon oils and waxes. Examples are mineral oil, petrolatum, paraffin, ceresin, ozokerite, microcrystalline wax, polyethylene, and perhydrosqualane.

2. Silicone oils, such as polydi ethylsiloxanes, methylphenyl- 0 polyslloxanes, water-soluble and alcohol-soluble silicone-glycol copolymers.

3. Trfglyceride fats and oils, such as those derived from vegetable, animal and marine sources. Examples include castor oil, safflower oil, cotton seed oil, corn oil, olive oil, cod liver oil, 5 almond oil, avocado oil, palm oil, sesame oil, and soybean oil.

4. Acetoglyceride esters, such as acetylated monoglycerides.

5. Ethoxylated glycerides, such as ethoxylated glyceryl mono- stearate.

6. Alkyl esters of fatty acids having 10 to 20 carbon atoms. 0 Methyl, isopropyl and butyl esters of fatty acids are especially useful herein. Examples include hexyl laurate, isohexyl laurate, isohexyl palmltate, isopropyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, isopropyl isostearate, diisopropyl adipate, diisohexyl adipate, dihexyldecyl adipate, diiso- 5 propyl sebacate, lauryl lactate, myristyl lactate, and cetyl lactate.

7. Alkenyl esters of fatty acids having 10 to 20 carbon atoms. Examples thereof include oleyl myristate, oleyl stearate, and oleyl oleate.

8. Fatty adds having 9 to 22 carbon atoms. Suitable examples include pelargonlc, laurlc, myristic, palmitic, stearic, isostearic, hydroxystearic, oleic, linoleic, ricinoleic, arachldonic, behenic, and erudc acids. 9. Fatty alcohols having 10 to 22 carbon atoms. Lauryl , myris- tyl, cetyl, hexadecyl, stearyl, isostearyl, hydroxystearyl , oleyl, ricinoleyl, behenyl, erucyl, and 2-octyl dodecyl alcohols are examples of suitable fatty alcohols.

10. Fatty alcohol ethers. Ethoxylated fatty alcohols of 10 to 20 carbon atoms include the lauryl, cetyl, stearyl, isostearyl, oleyl, and cholesterol alcohols having attached thereto from 1 to 50 ethylene oxide groups or 1 to 50 propylene oxide groups, or a mixture thereof.

11. Ether-esters such as fatty acid esters of ethoxylated fatt alcohols. 12. Lanolin and its derivatives. Lanolin, lanolin oil, lanoli wax, lanolin alcohols, lanolin fatty acids, isopropyl lanolate, ethoxylated lanolin, ethoxylated lanolin alcohols, ethoxylated choles terol, propoxylated lanolin alcohols, acetylated lanolin, acetylate lanolin alcohols, lanolin alcohols linoleate, lanolin alcohol ricinoleate, acetate of lanolin alcohols ricinoleate, acetate o ethoxylated alcohols-esters, hydrogenolysis of lanolin, ethoxylate hydrogenated lanolin, ethoxylated sorbitol lanolin, and liquid an semisolid lanolin absorption bases are illustrative of emollient derived from lanolin. 13. Polyhydrlc alcohols and polyether derivatives. Propylen giycol, dipropylene giycol, polypropylene giycol (M. . 2000-4000) polyoxyethylene polyoxypropylene glycols, polyoxypropylene polyoxy ethylene glycols, glycerol, ethoxylated glycerol, propoxylated gly cerol, sorbitol, ethoxylated sorbitol, hydroxypropyl sorbitol, poly ethylene giycol (M.H. 200-6000), methoxy polyethylene glycols, poly ethylene oxide] homopolymers (M.W. 100,000-5,000,000), polyalkylen glycols and derivatives, hexylene giycol (2-methyl-2,4-pentanediol) 1,3-butylene giycol, 1,2,6-hexanetriol, ethohexadiol USP (2-ethy 1,3-hexanediol), C ₁₅ -C _lβ vicinal giycol, and polyoxypropylene deriva tives of trimethylolpropane are examples thereof.

14. Polyhydric alcohol esters. Ethylene giycol mono- an di-fatty acid esters, diethylene giycol mono- and di-fatty aci esters, polyethylene giycol (M.W. 200-6000) mono- and di-fatty aci esters, propylene giycol mono- and di-fatty acid esters, polypropylen

giycol 2000 monooleate, polypropylene giycol 2000 moπostearate, ethoxylated propylene propylene giycol monostearate, glyceryl mono- and di-fatty add esters, polyglycerol poly-fatty acid esters, eth¬ oxylated gylceryl monostearate, 1,3-butylene giycol monostearate, 1,3-butylene giycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters.

15. Wax esters, such as beeswax, spermaceti, myristyl myristate, stearyl stearate. 16. Beeswax derivatives, e.g., polyoxyethylene sorbitol beeswax. These are reaction products of beeswax with ethoxylated sorbitol of varying ethylene oxide content, forming a mixture of ether-esters.

17. Vegetable waxes including carnauba and candelilla waxes.

18. Phospholipids, such as lecithin and derivatives. 19. Sterols. Cholesterol, cholesterol fatty acid esters are examples thereof.

20. Amides, such as fatty acid amides, ethoxylated fatty acid amides, solid fatty acid alkanolamides.

The lotions further comprise from about 1% to about 10%, prefera- bly from about 2% to about 5%, of an emulsifler. The emulsifiers can be nonionic, anionic or cationic. Examples of satisfactory πonionic emulsifiers include fatty acid alcohols having 10 to 20 carbon atoms, fatty alcohols having 10 to 20 carbon atoms condensed with 2 to 20 moles of ethylene oxide or propylene oxide, alkyl phenols with 6 to 12 carbon atoms in the alkyl chain condensed with 2 to 20 moles of ethylene oxide, mono- and di-fatty acid esters of ethylene oxide, mono- and d1-fatty add esters of ethylene giycol wherein the fatty add moiety contains from 10 to 20 carbon atoms, diethylene giycol, polyethylene glycols of molecular weight 200 to 6000, propylene glycols of molecular weight 200 to 3000, glycerol, sorbitol, sorbitan, polyoxyethylene sorbitol, polyoxyethylene sorbitan and hydrophilic wax esters. Suitable anionic emulsifiers include the fatty acid soaps, e.g. sodium, potassium and triethanolamine soaps, wherein the fatty acid moiety contains from 10 to 20 carbon atoms. Other suitable anionic emulsifiers include the akali metal, ammonium or substituted ammonium alkyl sulfates, alkyl arylsulfonates, and alkyl ethoxy ether sulfonates having 10 to 30 carbon atoms in the alkyl moiety. The alkyl ethoxy ether sulfonates contain from 1 to 50 ethylene oxide

units. However, it 1s recognized that certain anionic emulsifiers ca result in a turbid formulation, and hence, anionic emulsifiers ar less preferred for use herein.

The balance of the lotion is water or a C ₂ or C ₃ alcohol, or mixture of water and the alcohol. The lotions are formulated b simply admixing all of the components together. Preferably th monoalkyl phosphate salt is dissolved in the mixture. Conventiona optional components can be included. One such additive is a thicken ing agent at a level from about 1% to about 10% of the composition Examples of suitable thickening agents include: cross-linked carboxy polymethylene polymers (sufficiently neutralized), magnesium aluminu silicate, carboxymethylcellulose, hydroxyethylcellulose, acrylic aci polymers (e.g., Acrysol ICS-I, available from Rohm & Haas Corpora tion), polyethylene glycols, gum tragacanth, gum kharaya, xanthan gum and bentonlte. Cationic polymers, such as cationic guar gum, are no preferred for use herein.

2. Creams.

Compositions of the present invention also can be formulated in cream form. The creams comprise safe and effective amounts of th monoalkyl phosphate salt; from about 0.1% to 95%, preferably fro about 10% to about 25%, of an emollient; the balance being water. Th emollients above described can also be used in the cream compositions Optionally, the cream form contains a suitable emulsifler, as previ ously described. When an emulsifler is included, it is is the compo sition at a level from about 3% to about 50%, preferably from about 5 to about 20%.

3. Solutions.

The compositions of this invention can also be formulated as solution. The solution form comprises a safe and effective amount the monoalkyl phosphate salt, usually at least about 0.01% up to abo 50% and preferably about 0.1% to about 10%; the balance being water a suitable organic solvent. Suitable organic materials useful as t solvent or a part of a solvent system are as follows: rropyle giycol, polyethylene giycol (M.W. 200-1000), polypropylene giyc (M.W. 425-2025), butylene giycol, glycerine, sorbitol esters, 1,2, hexanetriol, ethanol, isopropanol, diethyl tartrate, butanediol, a mixtures thereof.

These solutions can be applied to the skin as is, or else can be formul ted Into, for example, squeeze devices described below or as an aerosol and sprayed onto the skin from an aerosol container, or as a mouthwash composition and used as an oral rinse. The aerosol composi- tions further comprise from about 25% to about 80%, preferably from about 30% to about 50%, of suitable propel1ants. Examples of such propellants are the chlorinated, fluorinated and chlorofluorinated lower molecular weight hydrocarbons. Nitrous oxide, carbon dioxide, butane, and propane can also be used as propel1ant gases. These propellants are used at a level sufficient to expel the contents of the container.

Squeeze foamer packages are well known as exemplified by the disclosures in the following patents that are incorporated herein by reference. U.S. Pat. Nos. 3,709,437, Wright, issued Jan. 9, 1973; 3,937,364, Wright, issued Feb. 10, 1976; 4,022,351, Wright, issued May 10, 1977; 4,147,306, Bennett, issued Apr. 3, 1979; 4,184,615, Wright, issued Jan. 22, 1980; 4,598,862, Rice, issued July 8, 1986; and 4,615,467, Grogan et al., issued Oct. 7, 1986; and French Pat. 2,604,622, Verhulst, published Apr. 8, 1988. The above containers (packages) do not use any propellant and are therefore safe for the consumer and the environment. They create a foam from almost any surfactant composition. Although there is nc need to add foam boosters merely for the purpose of stabilizing the foam, such materials can be desirable. In some compositions the use of foam boosters can even be counterproductive since the foam has to break in order for the container to work properly. The composition is placed in the container reservoir (plastic squeeze bottle). Squeezing the container with the hand forces the composition through a foamer head, or other foam producing means, where the composition is mixed with air and then through a homogenizing means that makes the foam more homogeneous and controls the consistency of the foam. The foam is then discharged as a uniform, non-pressurized aerated foam.

The minimum pressure to activate the squeeze foamer is about 1 psig, typically from about 2 psig to about 7 psig. The minimum pressure is related to the size of the channels in the dispenser, the viscosity of the composition, etc.

In general, the density of the foam should be between about 0.002 and about 0.25 g/cc, preferably between about 0.01 and about 0.12 g/cc, and more preferably between about 0.02 and about 0.07 g/cc.

The carrier liquid in a mouthwash 1s generally a mixture o ethanol and water. The amount of ethaπol is generally from about 5 to about 60%, preferably from about 5% to about 25% by weight of th carrier. Water then constitutes the remainder of the carrier liqui mixture. These mouthwash compositions can also contain other optiona components such as emulsifying agents as previously described, flavor ing agents, sweeteners, and hu ectants. Other mouthwash formulation and methods for making mouthwashes useful in the present invention ar disclosed in U.S. Patent 4,323,551 to Parran, issued April 6, 1982 which is incorporated by reference herein. 4. Gels.

Compositions herein can be formulated into a gel form by simpl admixing a suitable thickening agent to the previously describ solution compositions. Examples of suitable thickening agents ha been previously described with respect to the lotions.

The gelled compositions comprise a safe and effective amount the monoalkyl phosphate salt, from about 0.5% to about 20%, preferabl from about 1% to about 10%, of the thickening agent; the balance bei water. 5. Solids.

The compositions of this invention can also be formulated in solid form, e.g., a stick-type composition. Such compositions co prise a safe and effective amount of the monoalkyl phosphate salt a from about 0.01% to about 99%, preferably from about 60% to about 90 of the previously described emollients. This composition can furth comprise from about 0.1% to about 20%, preferably from about 5% about 15%, of a suitable thickening agent, and optionally emulsifie and water. Thickening agents previously described with respect lotions are also suitable herein. 6. Soaps.

The compositions of this invention can also be formulated into liquid or solid (e.g., bar) soap matrix. Such compositions comprise safe and effective amount of the monoalkyl phosphate salt ranging fr about 0.1% to about 99%; and from about 1% to about 99% of an excip ent such as those previously described. Optionally, the soap contai a suitable e ulsifier as previously described. When an emulsifier included, it is in the composition at a level from about 10% to abo 50%.

7. Dentifrices.

The compositions of this invention can also be formulated as dentifrices. Such dentifrices, especially toothpaste, comprise a safe and effective amount of the monoalkyl phosphate salt ranging from about 0.1% to about 20% by weight of the composition. Toothpaste compositions conventionally contain abrasive materials, sudsing agents, binders, humectants, flavoring and sweetening agents. Suitable dentifrice compositions and the methods of their manufacture useful in the present invention are fully set forth in U.S. Patent 3,535,421 to Briner et al., issued October 20, 1970, which is incor¬ porated by reference herein.

8. Shampoos.

Compositions of this invention also can be formulated in a shampoo form. The shampoos comprise a safe and effective amount of the diamine monoalkyl phosphate salt ranging from about 0.1% to about 99%; from about 5% to about 60% of a synthetic surfactant; and the balance water. A secondary surfactant can also be utilized, however, such secondary surfactant should be neutralized by a diamine as described above. These shampoos can contain a variety of nonessential optional components. Such conventional optional ingredients are well known to those skilled in the art, e.g., preservatives, such as benzyl alcohol, ethyl paraben, propyl paraben and imidazolidinyl urea; cationic surfactants, such as cetyl trimethyl ammonium chloride, stearyldi- methyl benzyl ammonium chloride, and di(partially hydrogenated tallow) dimethylammonium chloride; thickeners and viscosity modifiers such as diethanolamide of a long-chain fatty acid (e.g. PEG 3 lauramide), block polymers of ethylene oxide and propylene oxide, sodium chloride, sodium sulfate, polyvinyl alcohol, and ethyl alcohol; pH adjusting agents, such as dtric acid, succinic acid, phosphoric acid, sodium carbonate; perfumes; dyes; and, sequestering agents, such as disodium ethylenediamine tetraacetate. Such agents generally are used indivi¬ dually at a level of from about 0.01% to about 10%, preferably from about 0.5% to about 5.0% by weight of the composition. Additional minor components can be added to the compositions of this invention in order to increase their attractiveness, versatility, and shelf-life. Perfumes and water soluble, pharmaceutically accept¬ able dyes or food colors can be added to enhance the attractiveness of

these compositions. Antifungal and antimicrobial agents are useful in preventing mold or bacterial contamination and in increasing the shelf-life of the compositions. Conventional antibacterial agents can be included in the present compositions at levels of from about 0.1% to about 4%, preferably from about 0.2% to about 1%. Typical antibac¬ terial agents which are suitable for use herein are 3,4-di- and 3,4',5-tribromosalicylanildes; 4,4'-dichloro-3-(trifluoromethyl)car- banilide; 3,4,4'-trichlorocarbanilide; phenoxy ethanol or propanol ; chlorhexidene salts; hexamidine salts; Irgasan DP 300 (Triclosan); salicylic acid; parachlorometaxylenol; Octopirox; and mixtures of these materials. For general purposes skin cleansing compositions having a pH range from about 5.0 to about 8.0 are desirable. If necessary, the pH of these compositions can be adjusted downward using citric or lactic acid. For skin cleansers which deal with more sensitive skin surfaces, such as in vaginal and perianal cleansers, a pH of about 6.5 is desirable. These and other minor modifications can be made without materially altering or departing from the basic concept of this invention.

The nature of the foam produced determines the usefulness of the present compositions. In order for a foam to be useful as a skin cleansing agent, it must have a uniform consistency, good spreadabil- ity, and good cleansing ability.

The foa ability and wettability characteristics are governed by the surface tension of the skin cleansing composition. The surface tension for the compositions of this invention varies from about 20 to 70 dynes/cm. For general skin cleansing compositions a range of fro about 23 to about 50 dynes/cm is preferred. Liquid composition having a surface tension in the lower portion of this range posses greater spreading and better wetting characteristics with increase foamability. Foamable compositions having higher surface tension generally provide more stable foams but are also more difficult t cause to foam and require more force to extrude the foam.

The foam-producing skin cleansing compositions of this inventio are particularly advantageous in that they leave a minimum amount o surfactant residue on the surface of the skin. This has been achieve in part by utilizing a low percentage of total surfactants in the ski cleansing compositions itself, and by preparing foams with unusuall low density. The present compositions provide foam densities provid

good cleansing ability and more Importantly, leave a negligible amount of surfactant residue on the surface of the skin upon rinsing or flattening, thereby preserving skin elasticity, and reducing transepi- der al moisture loss. The cleansing ability of these aerated foams is a direct function of the cleansing ability of the surfactant solution itself which produces the foam.

The following non-limiting examples illustrate embodiments of the subject invention wherein both essential and optional ingredients are combined. It is to be understood that these examples are for illus¬ trative purposes only and are not to be construed as limiting the scope of the invention thereto.

EXAMPLE I 1 mole of monolauryl phosphate acid is heated over a steam bath to about 50'C until molten. 1 mole of N,N,N',N'-tetrakis(2-hydroxy- propyl)-ethylenediamine (available as Quadrol from BASF Corporation) is heated in a separate beaker to 50 ^* C until pourable.

The molten phosphate is slowly added to the N,N,N',N'-tetrakis(2- hydroxypropyl)-ethylenediamine. The phosphate is added until a pH of 5.0 to 9.0 is reached (preferably 7.0). The resulting N,N,N',N'- tetrakis(2-hydroxypropyl)-ethylenediamine monol urylphosphate is then cooled to form a clear, yellow solid.

This solid can be used as a solid bar or as a material to produce liquid cream or gel product. Application of approximately 0.5 grams to the skin will provide a foaming cleanser possessing good cleansing power and detergency, which is mild and non-1rr1tating, and leaves little, if any, residual film remaining on the cleansed surface of the skin.

Substantially similar results are obtained when the monolauryl phosphate add 1s replaced with an equivalent amount of monococoyl- phosphate add, monolaurylphosphate acid, monoisostearylphosphate acid, monostearylphosphate acid, monomyristylphosphate acid, mono- oleoylphosphate acid, monopalmitylphosphate acid, monocaprylphosphate acid, monoundecylenylphosphate acid, monotridecylenylphosphate acid, mono(methylmyristyl)phosphate acid, mono(isopropyl!auryl)phosphate acid, mono(isodecylneopentyl)phosphate acid, monocetylphosphate acid, and mono(isopropylmyristyl)phosphate acid and mixtures thereof.

EXAMPLE II A facial cleansing composition for topical administration is prepared by combining the following ingredients:

Ingredient? Percent w/w

N,N,N',N'-tetrakis(2-hydroxypropyl)- ethylenediamine monolaurylphosphate 2.500

Butylene Giycol 2.500

Methylparaben 0.250

Propylparaben 0.150

Potassium coco(hydrolysed animal protein) ¹ 0.032

Glycerin 2.000

Aloe Vera 0.500

Fragrance 0.050

Color 0.170

Xanthan gum ² 0.050

Water q.s.

¹ Available as Lamepon S from Henkel Corporation

² Available as Keltrol T from Kelco Corporation

EXAMPLE III A facial cleansing cream composition for topical administration is prepared by combining the following ingredients:

Ingredients Percent w/w

N,N,N',N'-tetrakis(2-hydroxypropyl)- ethylenediamine monolaurylphosphate 27.000

Laurie acid 4.000

N,N,N',N'-tetrakis(2-hydroxypropyl)- ethylenediamine ¹ 4.000

Carboxyvinyl polymer ² 0.200

Glycerine 8.000

Sorbitol 2.000

Water q.s.

¹ Available as Quadrol from BASF-Wyandotte

² Available as Carbopol 941 from B.F. Goodrich Company

EXAMPLE VI A facial shaving foam composition for topical administration is prepared by combining the following ingredients:

Ingredients Percent w/w N,N,N',N'-tetrakis(2-hydroxypropy1)- ethylenediamine monolaurylphosphate 7.000 N,N,N',N'-tetrak1s(2-hydroxypropyl)-

IS

WHAT IS CLAIMED IS: