FIELD OF THE INVENTION

This invention relates to liquid personal cleansing compositions which contain polyvalent metal cations. The liquid personal cleansing compositions of the present invention additionally comprise an anionic surfactant, an amphoteric surfactant, a skin conditioner ingredient and water. These compositions have a viscosity ranging from about 1,000 to about 50,000 cps. Such compositions are low cost, very mild to the skin, and have an improved rinse profile compared to certain compositions which do not contain polyvalent metal cations.

BACKGROUND OF THE INVENTION Liquid personal cleansing products are becoming increasing more popular in the United States and around the world. Desirable liquid personal cleansing compositions must meet a variety of criteria. For example, in order to be acceptable to consumers, a liquid personal cleansing product must exhibit good cleaning properties, mildness/low irritancy with respect to the skin, and good lathering and rinse feel properties. Although it is well known that ideal personal cleansing products should cleanse the skin gently, without drying or irritating the skin, most lathering soaps, shower and bath products and bars fail in this respect. Certain synthetic surfactants are known to be mild. However, a major drawback of most mild synthetic surfactant systems is that personal cleansing products into which they are incorporated have poor lather performance compared to the highest soap bar standards. Thus, surfactants that are among the mildest, such as sodium lauryl glyceryl esther sulfonate (AGS), contribute to marginal lathering characteristics of the product into which they are incorporated. The use of known high sudsing anionic surfactants with lather boosters, on the other hand, can yield acceptable lather volume and quality, but at the expense of clinical skin mildness. These two facts make the surfactant selection, the lather and mildness benefit formulation process a delicate balancing act.

Despite the many years of research that have been expended by the toiletries industry on personal cleansing, the broad mass of consumers remain dissatisfied with

the mildness of present day cleansing compositions, finding, for example, that they have to apply a separate cosmetic lotion or cream moisturizer to the skin after using a shower or bath preparation in order to maintain skin suppleness an dehydration and the counteract the delipidizing effect ofthe cleanser. U.S. Patent 5,409,640 to Giret et al; Issued April 25, 1995 and U.S. Patent

Application Serial No. 08/327,911 describe certain liquid personal cleansing compositions which exhibit excellent mildness. Moreover, when these liquid personal cleansing compositions are used in combination with the polymeric diamond meshed sponge described in U.S. Patent Application Serial No. 08/327,911, they exhibit excellent lathering characteristics. These liquid personal cleansing compositions comprise certain anionic surϊactants, certain amphoteric surfactants, skin conditioner ingredients and water.

U.S. Patent 5,409,640 describes and exemplifies personal cleansing compositions wherein the anionic surfactant consists entirely of sodium laureth- sulfate. Unfortunately, it has now been found that personal cleansing products which contain sodium laureth sulfates as the sole anionic surfactant can have a less than optimal rinse profile when they are used with hard water. For example, when these types of compositions were tested in consumer tests under hard water conditions, consumers reported that they rinsed away too easily. These consumers required a slick rinse feel in order to expect good skin effects. If the composition rinsed away too easily and did not leave behind an oily feeling, the consumers perceived this negatively.

It has now been found that the compositions of the present invention, which contain polyvalent metal cations, have comparable mildness and lathering properties to the compositions described in U.S. Patent 5,409,640, but exhibit a superior rinse profile, particularly under hard water conditions, compared to compositions which contain sodium laureth -3 sulfate as the sole anionic surfactant and which do not contain polyvalent metal cations.

SUMMARY OF THE INVENTION The present invention relates to liquid personal cleansing compositions which are relatively low cost to prepare, but which exhibit excellent mildness and rinse feel properties. These compositions comprise from about 1% to about 30% of an anionic surfactant, from about 1% to about 15% of an amphoteric surfactant, from about 0.5% to about 5% of a polyvalent metal cation, water and from about 0.1% to about 30% of a skin conditioner ingredient.

The weight ratio ofthe anionic surfactant to the amphoteric surfactant ranges from about 4: 1 to about 1 :4. The viscosity of the liquid personal cleansing compositions ofthe present invention ranges from about 1,000 to bout 50,000 cps. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to liquid personal cleansing compositions which contain polyvalent metal cations. These polyvalent metal cations, when used in the disclosed amounts in combination with the disclosed amounts of the anionic and amphoteric surfactants described herein, contribute to an improved rinse profile for the personal cleansing compositions herein. The liquid personal cleansing compositions of the present invention exhibit good mildness properties and are relatively inexpensive to manufacture. Moi over, when used in combination with a light weight polymeric diamond meshed sponge, such as that disclosed in U.S. Patent 5, 144,744 to Campagnoli; Issued September 8, 1992 (herein incoφorated by reference), the liquid personal cleansing compositions ofthe present invention exhibit good lathering properties.

The liquid personal cleansing compositions of the present invention are described in detail as follows: I. The Ingredients

A. The Anionic Surfactant The liquid personal cleansing compositions of the present invention contain from about 1% to about 30% by weight of the composition of an anionic surfactant. Preferably, the liquid personal cleansing compositions of the present invention contain from about 3% to about 17% by weight of an anionic surfactant, more preferably from about 6% to about 14%, and most preferably from about 8% to about 12%.

Anionic surfactants suitable for inclusion in the compositions of the present invention can generally be described as mild synthetic detergent surfactants. These include, for example, ethoxylated alkyl sulfates, alkyl glyceryl sulfonates, methyl acyl taurates, fatty acyl glycinates, N-acyl glutamates, acyl isethionates, alkyl sulfosuccinates, alpha-sulfonated fatty acids, their salts and/or esters, alkylphosphate esters, ethoxylated alkyl phosphate esters, acyl sarcosinates and fatty acid/protein condensates, and mixtures thereof. Alkyl and/or acyl chain lengths for these surfactants are C8-C22, preferably C10-C 18

Preferred for use herein from the standpoint of optimum mildness and lathering/rinse characteristics are the salts of sulfuric acid esters of the reaction product of 1 mole of a higher fatty acid alcohol and from about 1 to about 12 moles of ethylene oxide, with sodium and magnesium being the preferred counterion.

Particularly preferred are the alkyl sulfates containing from about 2 to about 4 moles of ethylene oxide, such as sodium laureth-2 sulfate, magnesium sodium laureth-3.6 sulfate and sodium laureth-3 sulfate. From a cost standpoint, however, it is desirable to minimize the level of magnesium sodium laureth sulfates present in the liquid personal cleansing compositions herein. Therefore, sodium laureth-n sulfate, wherein n=2-4, is most preferred for use herein.

The anionic surfactant preferably comprises less than about 10%, more preferably less than about 5%, most preferably less than 1%, magnesium sodium laureth-n sulfate, wherein n=l-12. The anionic surfactant preferably comprises at least about 50%, more preferably at least about 75%, and most preferably at least about 90% by weight of sodium laureth-n sulfate, wherein n = 1-12, more preferably wherein n = 2-4.

B. The Amphoteric Surfactant

The liquid personal cleansing compositions of the present invention contain from about 1% to about 15% by weight of an amphoteric surfactant. Preferably the liquid personal cleansing compositions of the present invention comprise from about

3% to about 12%, more preferably from about 4% to about 8% of an amphoteric surfactant.

Amphoteric surfactants suitable for use in the compositions of the invention include:

(a) imidazolinium surfactants of formula (II)

wherein Ri is C7-C22 alkyl or alkenyl, R2 is hydrogen or CH2Z, each Z is independently CO2M or CH2CO2M, and M is H, alkali metal, alkaline earth metal, ammonium or alkanolammonium; and/or ammonium derivatives of formula (III)

C ₂ H ₄ OH R ₁ CONH(CH ₂ ) ₂ N ⁺ CH ₂ Z

^R 2 wherein Ri, R2 and Z are as defined above;

(b) aminoalkanoates of formula (IV) RιNH(CH ₂ )nCO ₂ M

and iminodialkanoates of formula (V)

R ₁ N[(CH ₂ ) _m CO ₂ M]2 wherein n and m are numbers from 1 to 4, and R _j and M are independently selected from the groups specified above; and (c) mixtures thereof.

Suitable amphoteric surfactants of type (a) are marketed under the trade name Miranol and are understood to comprise a complex mixture of species. Traditionally, the Miranol s have been described as having the general formula II, although the CTFA Cosmetic Ingredient Dictionary, 3rd Edition indicates the non-cyclic structure III. In practice, a complex mixture of cyclic and non-cyclic species is likely to exist and both definitions are given here for sake of completeness. Preferred for use herein, however, are the non-cyclic species.

Examples of suitable amphoteric surfactants of type (a) include compounds of formula II and/or III in which Rj is CgHi γ (especially iso-capryl), C9H19 and Cj 1H23 alkyl. Especially preferred are the compounds in which R\ is C9H19, Z is CO2M and R2 is H; the compounds in which R is Ci 1H23, Z is CO2M and R2 is CH2CO2M; and the compounds in which K\ is C _j 1H23, Z is CO2M and R ₂ is H.

In CTFA nomenclature, materials suitable for use in the present invention include sodium lauroamphoacetate, cocoamphocarboxypropionate, cocoamphocarboxy propionic acid, and cocoamphoacetate and cocoamphodiacetate (otherwise referred to as cocoamphocarboxyglycinate). Sodium lauroamphoacetate is preferred for use herein. Specific commercial products include those sold under the trade names of Macham 1L-80 (Maclntyre), Empigen CDL60 and CDR 60 (Albright & Wilson), Miranol C2M Cone. N.P., Miranol C2M Cone. O.P., Miranol C2M SF, Miranol CM Special (Miranol, Inc.); Alkateric 2CLB (Alkaril Chemicals); Amphoterge W-2 (Lonza, Inc.); Monateric CDX-38, Monateric CSH-32 (Mona Industries); Rewoteric Am-2C (Rewo Chemical Group); and Schercotic MS-2 (Scher Chemicals).

It will be understood that a number of commercially-available amphoteric surfactants of this type are manufactured and sold in the form of electroneutral complexes with, for example, hydroxide counterions or with anionic sulfate or sulfonate surfactants, especially those of the sulfated Cg-Ci g alcohol, Cg-Ci ethoxylated alcohol or Cg-Ci g acyl glyceride types. Preferred from the viewpoint of mildness and product stability, however, are compositions which are essentially free of (non-ethoxylated) sulfated alcohol surfactants. Note also that the concentrations and weight ratios ofthe amphoteric surfactants are based herein on the uncomplexed

forms of the surfactants, any anionic surfactant counterions being considered as part ofthe overall anionic surfactant component content.

Examples of suitable amphoteric surfactants of type (b) include salts, especially the triethanolammonium salts and salts of N-lauryl-beta-amino propionic acid and N-lauryl-imino-dipropionic acid. Such materials are sold under the trade name Deriphat by General Mills and Mirataine by Miranol Inc. Amphoterics preferred for use herein, however, are those of formula II and/or HI.

C. The Polyvalent Cation

Another essential component ofthe liquid personal cleansing compositions of the present invention is a polyvalent metal cation, or mixture of polyvalent cations. Suitable polyvalent metal cations include divalent and trivalent metals, with divalent metals being preferred. Exemplary metal cations could include alkaline earth metals, such as magnesium, and zinc and copper and trivalent metals, such as aluminum and iron. Most preferred is magnesium. The polyvalent metal cation component should be present in the liquid personal cleansing composition in soluble, free ion form.

The polyvalent metal cation is preferably added to the liquid personal cleansing compositions herein in the form of a soluble metal salt or metal hydroxide. For example, the polyvalent cation is typically added to the liquid personal cleansing compositions herein in the form of an inorganic salt, such as acetate, halide (e.g., chloride), nitrate, or sulfate. Preferred inorganic salts are chloride, sulfate and acetate. Preferably at least about 75%, more preferably at least about 90% of the polyvalent metal cations are added to the liquid personal cleansing compositions herein in the form of an inorganic salt or metal hydroxide. The polyvalent cation can also be added in the form of a surfactant, such as an anionic surfactant (including the anionic surfactants hereinbefore described), but the amount of polyvalent cation that is added in the form of a surfactant is preferably minimized. Preferably, less than 10%, more preferably less than 5%, most preferably less than 1% ofthe salt is in the form of a surfactant.

The liquid personal cleansing compositions of the present invention contain from about 0.5% to about 5% of polyvalent metal cations. Preferably, the liquid personal cleansing compositions herein contain from about 0.5% to about 4.1% polyvalent metal cations, more preferably from about 0.5% to about 3.1% polyvalent metal cations.

In order to obtain a low cost, mild liquid personal cleansing product of the present invention, which exhibits good rinsing characteristics, it is critical that the level of polyvalent metal cation present in the compositions of the present invention be within the range from 0.5% to 5%. In general, the higher the level of polyvalent

cations within this range, the better the rinse feel profile. However, increasing the level of polyvalent cations within this range also has the effect of reducing the lather ofthe compositions herein. When the level of polyvalent cations in the compositions exceeds about 5%, the lathering characteristics can begin to become unacceptable from a consumer standpoint.

D. Water

The liquid personal cleansing compositions of the present invention further comprise water. Water is typically present in the liquid personal cleansing compositions herein in an amount ranging from about 40% to about 65%, preferably from about 45% to about 60%, more preferably from about 50% to about 60%. It is preferred to use deionized water when preDaring the compositions described herein. Polyvalent metal cations are added to the compositions in salt or base form to increase the free polyvalent cation level in the final composition to within the prescribed range. Alternatively, tap water or other non-deionized water can be used, and the free polyvalent metal cation level can be increased, as applicable, to within the prescribed ranges hereinbefore described. Alternately, if applicable, the level of free polyvalent metal cations can be decreased by partially deionizing the water or by adding a sequestering agent or chelating agent to the compositions (e.g., ethylene diamine tetraacetic acid).

E. Skin Conditioner Ingredient

The liquid personal cleansing compositions of the present invention further comprise from about 0.1% to about 30%, preferably from about 0.5% to about 25%, more preferably from about 2% to about 20, most preferably from about 5% to about 20% a skin conditioner ingredient. The skin conditioner ingredient can comprise any skin conditioner known for use in personal cleansing compositions, such as, for example, the skin conditioner ingredients set forth in CTFA Cosmetic Ingredient Handbook. First Edition (1988), pp. 79-84.

Preferred skin conditioners for use herein include esters of fatty acids; glycerin mono-esters, glycerin di-esters, and glycerin tri-esters; epidermal and sebaceous hydrocarbons; lanolin and derivatives; mineral oil; silicone oil; silicone gum; vegetable oils, vegetable oil adducts, nonionic polymers; cationic polymers, polyols selected from the group consisting of glycerin, glycerol, propylene glycol, polypropylene glycols, polyethylene glycols, ethyl hexanediol, hexylene glycols, and mixtures of any of these ingredients.

The skin conditioner comprising the liquid personal cleansing compositions herein preferably comprises a cationic or nonionic polymer. These polymers are

typically present in the liquid personal cleansing compositions at a level from about 0.01% to about 5%, preferably from about 0.04% to about 2% and especially from about 0.05% to about 1%. The polymer is found to be valuable for enhancing the creaminess and quality ofthe foam as well as providing a skin conditioning utility. Suitable polymers are high molecular weight materials (mass-average molecular weight determined, for instance, by light scattering, being generally from about 2,000 to about 3,000,000, preferably from about 5,000 to about 1,000,000).

Representative classes of polymers include cationic and nonionic polysaccharides; cationic and nonionic homopolymers and copolymers derived from acrylic and/or methacrylic acid; cationic and nonionic cellulose resins; cationic copolymers of dimethyldiallylammonium chloride and acrylic acid; cationic homopolymers of dimethyldiallylammonium chloride; cationic polyalkylene and ethoxypolyalkylene imines; quaternized silicones, and mixtures thereof.

By way of exemplification, cationic polymers suitable for use herein include cationic guar gums such as hydroxypropyl trimethyl ammonium guar gum (d.s. of from 0.11 to 0.22) available commercially under the trade names Jaguar C-14- S(RTM) and Jaguar C-17(RTM) and also Jaguar C-16(RTM), which contains hydroxypropyl substituents (d.s. of from 0.8-1.1) in addition to the above-specified cationic groups, and quaternized cellulose ethers available commercially under the trade names Ucare Polymer JR and Celquat. Other suitable cationic polymers are homopolymers of dimethyldiallylammonium chloride available commercially under the trade name Merquat 100, copolymers of dimethyl aminoethylmethacrylate and acrylamide, copolymers of dimethyldiallylammonium chloride and acrylamide, available commercially under the trade names Merquat 550 and Merquat S, quaternized vinyl pyrrolidone acrylate or methacrylate copolymers of amino alcohol available commercially under the trade name Gafquat, and polyalkyleneimines such as polyethylenimine and ethoxylated polyethylenimine.

The skin conditioner ingredient comprising the liquid personal cleansers herein also preferably comprises a vegetable oil. The vegetable oil preferably comprises from about 1% to about 15% of the liquid personal cleansing compositions, more preferably from about 1% to about 10%.

The skin conditioner ingredient comprising the liquid personal cleansers herein also preferably comprise glycerin. Glycerin is typically included at levels of from about 1% to about 5% ofthe liquid personal cleansing compositions, preferably from about 2% to about $% ofthe liquid cleansing compositions.

The skin conditioner ingredient comprising the liquid cleansers herein also preferably comprises PEG 6 C8/C10 glycerides. PEG 6 is preferably included in the

liquid personal cleansing compositions herein at levels ranging from about 1% to about 5%, more preferably from about 2% to about 4%.

The skin conditioner ingredient herein can also include a vegetable oil adduct. The compositions ofthe invention preferably contain from about 0.1% to about 15%, preferably from about 0.25% to about 10%, more preferably from about 0.5% to about 5% of a vegetable oil adduct which preferably has the general formula (I):

(CH ₂ ) _χ CH ₃

wherein x, y are integers of from 3 to 9, R3 to R4 are independently selected from saturated and unsaturated C7-C22 hydrocarbyl, each Z\ is CO2M or H with at least one Zi being CO2M and wherein M is H, alkali metal, alkaline earth metal, ammonium or alkanolammonium.

Materials of this kind can generally be described as adducts prepared from vegetable oils containing non-conjugated polyunsaturated fatty acid esters which are conjugated and elaidinized then modified by Dies-Alder addition with a member of the group consisting of acrylic acid, fumaric acid and maleic anhydride. The adducts and their preparation are described in US-A-4740367, the adducts being marketed under the trade name Ceraphyl GA (Van Dyke). Preferred vegetable oils adducts are those of Formula I prepared from soybean oil (x + y = 12) and adducts derived by Dies- Alder addition of vegetable oils with fumaric acid. A preferred method of preparing adducts herein is to react two moles of vegetable oil with one mole of the dienophile in the presence of catalytic amounts of iodine, the conjugation and elaidinization agent. This produces a 50:50 blend of adduct together with disproportionated (conjugated) vegetable oil. F. Optional Ingredients 1. Other Surfactants

The compositions herein preferably also contain from about 0.1% to about 20%, more preferably from about 0.1% to about 10%, and especially from about 1% to about 5% of a nonionic or betaine surfactant. Preferred herein from the viewpoint of optimum lathering and mildness are nonionic surfactants selected from C 12-C 14 fatty acid mono- and diethanolamides and polyhydroxy fatty acid amine surfactants having the general formula (VII)

0 R li X Rg -C-N— Z ₂ where R9 is H, C1-C4 hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl or a mixture thereof, Rg is C5-C31 hydrocarbyl and Z is a polyhydroxyhydrocarbyl having a linear chain with at least 3 hydroxyls directly connected to said chain, or an alkoxylated derivative thereof.

The preferred polyhydroxy fatty acid amide surfactants are those in which R9 is C 1.4 alkyl, preferably methyl, and Rg is C7-C19 alkyl or alkenyl, more preferably straight-chain C9-C17 alkyl or alkenyl, or mixture thereof; and Z2 is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3 hydroxyls directly connected to the chain, or an alkoxylated derivative (preferably ethoxylated or propoxylated) thereof. Z2 preferably will be derived from a reducing sugar in a reductive amination reaction; more preferably Z2 is a glycityl. Suitable reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose, and xylose. As raw materials, high dextrose corn syrup, high fructose corn syrup, and high maltose corn syrup can be utilized as well as the individual sugars listed above. These corn syrups may yield a mix of sugar components for Z2. It should be understood that it is by no means intended to exclude other suitable raw materials. Z2 preferably will be selected from the group consisting of -CH2(CHOH) _n -CH2OH,- CH(CH ₂ OH)-(CHOH) _n . _λ -CH ₂ OH, -CH ₂ .(CHOH)2(CHOR ^, )(CHOH)-CH ₂ OH, where n is an integer from 3 to 5, inclusive, and R' is H or a cyclic or aliphatic monosaccharide, and alkoxylated derivatives thereof. Most preferred are glycityls wherein n is 4, particularly -CH2-(CHOH)4-CH2OH.

The most preferred polyhydroxy fatty acid amide has the formula Rg(CO)N(CH ₃ )CH2(CHOH)4CH ₂ OH wherein Rg is a C _] 1-C17 straight chain alkyl or alkenyl group.

Betaine surfactants suitable for inclusion in the composition of the invention include alkyl betaines ofthe formula R5RgR7N ⁺ (CH2) _n M (VII) and amido betaines ofthe formula (VLT.I)

R ₅ CO (CH ₂ ) _ιn N (CH ₂ ) _n M

Rn

wherein R5 is C12-C22 alkyl or alkenyl, Rg and R7 are independently C1-C3 alkyl, M is H, alkali metal, alkaline earth metal, ammonium or alkanolammonium, and n, m are each numbers from 1 to 4. Preferred

betaines include cocoamidopropyldimethylcarboxymethyl betaine and laurylamidopropyldimethylcarboxymethyl betaine.

2. Other

A number of additional optional materials can be added to the cleansing compositions. Such materials include proteins and polypeptides and derivatives thereof; water-soluble or solubilizable preservatives such as DMDM Hydantoin, Germall 1 15, methyl, ethyl, propyl and butyl esters of hydroxybenzoic acid, EDTA Euxyl (RTM) K400, Bronopol (2-bromo-2-nitropropane-l,3-diol), sodium benzoate and 2-phenoxyethanol; other moisturizing agents such as hylaronic acid, chitin , and starch-grafted sodium polyacrylates such as Sanwet (RTM) IM-1000, EvI-1500 and -2500 available from Celanese Superabsorbent Materials, Portsmith, VA, USA and described in US-A-4,076,663; low temperature phase modifiers such as ammonium ion sources (e.g. NH4 Cl); viscosity control agents; coloring agents; pearlescers and opacifiers such as ethylene glycol distearate, Tiθ2 and Tiθ2-coated mica; perfumes and perfume solubilizers etc.

II. Characteristics ofthe Liquid Personal Cleansing Compositions A. Ratio of Anionic Surfactant to Amphoteric Surfactant

The ratio of the anionic surfactant to amphoteric surfactant in the liquid cleansing compositions of the present invention ranges from about 4: 1 to about 1 :4, more preferably from about 3: 1 to about 1: 1, most preferably from about 2.5:1 to about 1.5: 1. B. Viscosity

The viscosity of the liquid personal cleansing compositions herein ranges from about 1,000 to about 50,000 cps, preferably from about 5,000 to about 45,000 cps, most preferably from about 10,000 to about 40,000 cps. The viscosity can be increased to within the target viscosity range by a variety of means including, but not limited to, the addition of a higher level of polyvalent metal cations within the range hereinbefore described.

The viscosity of the liquid personal cleansing compositions herein can be measured according to the method set forth hereinafter in the Analytical Methods section. C. Average Emulsion Droplet Size

The average size ofthe emulsion droplets within the liquid personal cleansing compositions of the present invention typically ranges from about 1 to about 20 microns.

D pH The pH of the compositions is preferably from about 4 to about 9, more preferably from about 4.5 to about 8.5, most preferably from about 4.5 to about 7.0, pH being controlled, for example, using a citrate buffer system.

III. Method of Preparation

A preferred method for preparing the composition herein comprises a) forming an aqueous phase comprising the water, the anionic and amphoteric surfactants and any water-based skin conditioning ingredients; b) forming an oil phase comprising the oil-based skin conditioner ingredients and the nonionic surfactants (if they are included in the composition); c) mixing the oil phase and the aqueous surfactant phase to form an oil- in- water emulsion. d) adding the polyvalent metal cation.

When a vegetable oil adduct is included in the composition, it is added after step (c), but before step (d).

ANALYTICAL METHODS Method for Measuring Viscositv of Liquid Personal Cleansing Compositions Herein

I. Scope

This method is applicable to the determination of the viscosity of the liquid personal cleanser compositions herein.

II. Principle A sample of product is adjusted to 25°C and the viscosity is measured using a cone and plate viscometer.

III. Apparatus Suggested Type or Source Viscometer Brookfield Models RVT DV-II

Viscosity <12,000 cps >12,000 cps

Cone CP 41 CP-52

RPM 1.0

Sample 2 ml

Constant Temperature Bath Capable of maintaining a temperature of and Flowthru Cooler 25°±0.1°C

Thermometer Accurate; of suitable range; graduated to O. TC Syringe 1 ml or 3 ml for CP 52 measurements;

3 ml for CP 41 measurements

IV. Set Up and Calibration

The viscometer should be mechanically set up and calibrated according to the Brookfield Digital Viscometer DV-II Operating Instructions once each day and/or after changing cones. V. Checks before Operating

A. Temperature and Bath Cooler. Turn scitches on both the bath and cooler. Make certain flow control on bath is all the way open. Brookfield standards are run at 25°C (very important -1°C deviation can result in a 6-9% difference in viscosity.) Bath temperature should be at least 25°C for standard and for samples. B. Make sure instrument is level (bubble is centered in circle of level indicator on viscometer). VI. Zeroing the Viscometer

A. Remove cone to zero the viscometer. Using wrench, apply to flat portion of spindle; turn spindle, keep wrench stationary. Spindle: Clockwise is ON

Spindle: Counter-clockwise is OFF

Note to see if cone is spinning properly. If motion is jerky, send unit back for repair.

B. After cone has been removed, put viscosity cup on, and secure by sliding hinge across bottom of cup.

C. Power on, Motor off.

D. Press Auto zero key.

E. Once screen is finished blinking, replace cone.

F. Turn speed to 1.0 RPM. G. To select cone, Press Spdl button, and enter cone number.

H. Hit CPS key (This key changes readout from "% of scale" to "cps"). I. Turn motor on, and check movement of cone.

J. Check sample cup for large dings. If these are present, the cup needs to be replaced. VII. Setting the Cone to Cup Gap

NOTE: This step will be performed daily, or any time a spindle is changed.

A. Place viscometer cap on instrument.

B. Turn speed knob on left side to 10 RPM.

C. Turn motor on (display will read — ). D. Press CPS key.

E. Hold sample cup while turning adjustment ring counter-clockwise until a number other than 0.0 is displayed. Let the reading stabilize. Turn the ring clockwise until decrease reading; counter-clockwise will increase the reading.

F. Once the display registers a reading, mark line with a pencil and turn adjustment ring clockwise one deviation (mark).

G. Place transparent tape over ring to keep in place.

H. Turn motor OFF. Set viscometer speed back to 1 RPM calibration. The viscometer is now ready for measurement. VIII. Viscositv Calibration/Measurement NOTE: Calibration of instrument should be performed 1 time per day minimum, or each time a spindle is changed. When using Brookfield Viscosity Standards, the standard deviation for the viscosity measurement is equal to 1% of full scale of the instrument, PLUS 1% ofthe rated viscosity ofthe standard.

EXAMPLES The following Examples of illustrative ofthe liquid personal cleansing compositions ofthe present invention.

Liquid personal cleansing composition having the following formulations are prepared:

Example I Example II

Component

Water 57.81 58.86

Sodium Laureth 3.0 Sulfate 10.5 10

Skin Conditioner Ingredients (Soybean Oil, PEG 6 18.7 18.8

C8/C10 glycerides, glycerin, palm kernel fatty acid, maleated soybean oil, polyquaterium 10)

Sodium Lauroamphoacetate 5.25 5

Cocamide CMEA 2.82 2.82

Perfume 1.6 1.6 pH adjusters 1.7 1.7

Magnesium sulfate 1.1 0.6

Preservatives 0.52 0.52

Whitβner ... 0.1

100 100

Physical Properties

Viscosity C/P#52, cps 26,600 22,400 % anionic surf actant 10.32 10 % MgS04 1.1 0.6

Examples I and II can be prepared according to the following procedure:

I . Clean and Sanitize making equipment. 2. In the main mix tank, form an aqueous phase comprising the water, the polymer (Polyquaternium 10), the amphoteric surfactant (Sodium Lauroamphoacetate), 1/2 ofthe total anionic surfactant (Sodium Laureth 3.0 Sulfate) and the preservatives and pH adjusters. The ingredients are mixed under agitation to ensure good mixing. The temperature ofthe mix tank is maintained at from 55-60°C. 3. In a separate mix tank, form an oil phase comprising the nonionic surfactant (Monamid CMA) and the oil-based skin conditioner ingredients (PEG-6 Caprylic/Capric Glyceride, palm kernel fatty acids and soybean oil). The temperature ofthe mix tank is maintained at 55-60°C. 4. Add hot oil phase to main mix tank once both tanks reach temperature. 5. Flush oil phase tank/lines with 0.5% ofthe formula water

6. Start cooling batch to 25 - 30°C and add the glycerin and the maleated soybean oil

7. Add the remaining half of anionic surfactant, magnesium sulfate and perfume

I I . Mix for 30 minutes minimum. Measure product viscosity after 30 minutes. 12. Adjust batch for viscosity, if needed.

13. Add 1 % of the total formula water.

The liquid personal cleansing compositions exemplified in Examples I and II are mild to the skin and have an optimal rinse profile. These qualities are perceived by experimental users in terms of positive skin effects.