HK1210697B - Rinse-off skin care compositions containing cellulosic materials - Google Patents

Description

Rinse-off skin care compositions comprising cellulosic materials

This application is a continuation-in-part of U.S. application No. 13/673,477, filed on November 9, 2012, the entire disclosure of which is hereby incorporated by reference herein for all purposes.

Technical Field

The compositions of the present invention are directed to rinse-off skin care compositions comprising hydrophobic linear cellulose particles that reduce the presence of oil-related substances on the skin.

Background Art

Oily skin is shiny, thick, and dark in color. Chronically oily skin often has enlarged pores and pimples, as well as other embarrassing spots. Furthermore, chronically oily skin may be prone to blackheads. In this type of skin, the oil-producing sebaceous glands are overactive and produce more oil than needed. The oil escapes the hair follicles and gives the skin an undesirable greasy sheen. The pores become enlarged, and the skin appears rough. While oily skin is common in teenagers, it can occur at any age.

Typically, individuals with oily skin attempt to treat the oily areas to prevent the onset of breakouts and reduce shine. Conventional treatments available include soap or surfactant-based cleansers, astringents with alcohol, and clay or mud masks. Oil-absorbing materials such as clay or salt have been used in attempts to treat this condition.

Individuals with oily or shiny skin conditions prefer treatments that reduce shine without drying out the skin. However, there is a lack of effective skin care products on the market today that meet these consumer needs. Oil-absorbing powders such as silica, aluminum starch, and talc have been used in cleansing products to help dry out oil on the skin's surface, but they also tend to dry out the skin, and oily skin tends to return quickly, typically within two to three hours.

Achieving benefits such as reduced skin oiliness from rinse-off compositions such as cleansers is particularly difficult because of the relatively short contact time between applying the cleansing composition to the skin and rinsing the cleansing composition from the skin.

Therefore, it would be desirable to have compositions and methods of treatment that address oily skin conditions while keeping the skin hydrated.

Summary of the Invention

The compositions and methods of the present invention are directed to a rinse-off skin care composition comprising: hydrophobic linear cellulose particles having an average length of from about 1 to about 1000 μm, a particle aspect ratio of from about 1000 to about 2, and a thickness of from about 1 to about 500 μm; at least one cleansing agent selected from saponified fats and surfactants; and a cosmetically acceptable carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a graph showing infrared spectra of various cotton particles and cellulose.

FIG2 is a graph of infrared spectra of various solvent extracts and polydimethylsiloxane from hydrophobic cotton particles.

FIG3 is a graph showing the oil absorption rates of hydrophilic and hydrophobic cotton particles.

FIG4 is a graph of the water absorption rates measured by various hydrophobic and hydrophilic cotton particles.

FIG5 is a graph showing the average oil absorption capacity of various hydrophobic and hydrophilic cotton particles.

FIG6 is a graph showing the average water absorption capacity of various hydrophobic and hydrophilic cotton particles.

FIG. 7 is a graph showing average sebum measurements for various cleanser formulations over time.

DETAILED DESCRIPTION

As used herein, the term "hydrophobic" refers to a material having a surface contact angle of less than 40 degrees with squalene and/or a surface contact angle of greater than 90 degrees with water. The term "surface contact angle" refers to the internal angle between a surface and a droplet placed on the surface. Surface tension (liquid) or surface free energy (solid) is considered to be the balance between the molecular interactions of liquid-liquid and gas-liquid or solid-solid and gas-solid at the interface. The term "contact angle" is a convenient and useful parameter for measuring the surface free energy and wettability of any given solid surface due to the solid's resistance to deformation. The contact angle is measured by measuring the angle formed between the substrate surface on which the droplet is placed and the tangent to the droplet surface from the contact point. A high contact angle corresponds to poor wettability of the liquid to the surface, and a low contact angle indicates good wettability. If the liquid spreads on the surface, the contact angle is considered to be zero and is referred to as complete wetting.

Contact angle measurements can be used to determine the wettability of human skin by a variety of liquids, including hydrophobic liquids such as squalene and hydrophilic liquids including water. Smaller contact angles with non-polar liquids (such as squalene) correspond to more hydrophobic materials, while smaller water contact angles correspond to more hydrophilic materials.

According to the methods and compositions of the present invention, the water contact angle of the hydrophobic linear cellulose particles is preferably greater than 90 degrees, preferably greater than 100 degrees, and even more preferably greater than 120 degrees.

As used herein, the terms "oil absorption capacity and retention" refer to the weight percentage of oil absorbed by the hydrophobic linear cellulose particles useful in the compositions and methods of the present invention. High oil absorption capacity and oil retention correspond to increased hydrophobicity. The hydrophobic linear cellulose particles of the compositions of the present invention preferably have an oil absorption capacity and oil retention of from about 150 to about 500, and more preferably from about 300 to about 500 (% oil weight/particle weight).

As used herein, the term "particle" refers to a small, localized object to which physical properties such as volume or mass can be attributed. As used herein, the term "powder" is used synonymously with "particle," as defined herein.

As used herein, the term "linear particle" refers to a particle having one dimension ("length") that is greater than another dimension ("width"). Linear particles are measured and defined by size by subjecting such particles to analysis against a series of sieves having different mesh sizes. Generally speaking, a sample of linear particles can have a distribution of particle sizes throughout the sample. Therefore, the linear particle sizes expressed herein are expressed as average particle sizes and reflect the average length of the particles contained within the sample.

Preferably, the linear particles useful in the compositions and methods of the present invention have a size of less than about 1000 μm in length, more preferably, in the range of about 1 to about 1000 μm, and most preferably in the range of about 10 to about 500 μm. The linear particles useful in the compositions and methods of the present invention preferably have a width of about 5 to about 25 μm. More preferably, they have a width of about 5 to about 20 μm.

As used herein, the term "particle aspect ratio" refers to the ratio of the length of a particle to its width. Preferably, the particles useful in the compositions and methods of the present invention have a particle aspect ratio of from about 2 to about 1000. More preferably, the particle aspect ratio is from about 2 to about 500 and most preferably, from about 5 to about 200.

As used herein, the term "cellulose" refers to a polysaccharide material composed of long, unbranched chains of linked glucose units having the chemical structure shown in Formula 1 below:

Cellulose, the most abundant biomass on Earth, provides humans with a functional, low-cost, and renewable raw material.

Cellulosic materials useful in the compositions and methods of the present invention may be derived from cotton, corn, wood and bamboo pulp, silk, cork, and the like. Preferably, the cellulosic materials useful in the compositions and methods of the present invention are derived from cotton. More preferably, the cellulose particles are derived from fibers recovered from waste materials after industrial processing. Such waste materials may be derived from garbage or from other pre-consumer cotton products such as clothing, carpets, furniture, and household goods industries. Synthetic or regenerated cotton or cellulosic materials may also be used as sources of cellulose particles useful in the compositions and methods of the present invention, including rayon, viscose, cellophane, and other cellulosic materials having uniform and reproducible molecular sizes and distributions.

Cellulosic materials useful in the compositions and methods of the present invention can be derived directly from source plants (referred to herein as "virgin" particles) or can be generated from cloth or nonwoven materials previously formed from plant or cellulose fibers (referred to herein as "regenerated" particles). For example, cotton cloth is processed by cutting the cotton fibers in lengths ranging from inches to microns to break the cloth into small particles and/or uniform fiber lengths. Several grades of such randomly cut fibers are available, white, dark, and unbleached, with an average fiber length of about 1 micron to about 1000 microns and preferably about 2 microns to about 500 microns.

It is believed that hydrophilic primary cellulose particles having similar size, aspect ratio, and other characteristics to the hydrophobic linear particles useful herein may also be used in the rinse-off cleaning compositions of the present invention.

Typical mechanical grinding processes such as those that can be used to reduce the size of cellulosic materials useful in the compositions and methods of the present invention are described, for example, in US Pat. No. 7,594,619 and US Pat. No. 6,656,487, which are hereby incorporated by reference herein.

Generally speaking, hydrophobic cellulose particles useful in the compositions of the present invention can be processed according to the following methods.

One such method comprises mixing a cellulosic material derived from industrial post-process waste as defined above with at least one grinding aid selected from the group consisting of water, fatty acids, synthetic polymers and organic solvents and mechanically grinding the mixture after mixing.

Another method of obtaining hydrophobic cellulose particles is to freeze the cellulose material originating from industrial process waste at low temperatures and then mechanically grind the frozen material.

The cellulose particles useful in the compositions and methods of the present invention may be further treated with a hydrophobizing agent to produce hydrophobic cellulose particles. For example, the cellulose particles may be treated with a hydrophobic coating agent. The hydrophobic coating agent may be any such agent known to those skilled in the art. Preferred hydrophobic coating agents chemically react with the cellulose particles to provide a durable covalent bond thereto and have a hydrophobic chemical backbone or substituent that provides a hydrophobic outer layer around each individual cellulose particle. The coating agent may, for example, react with hydroxyl groups, i.e., with available oxygen atoms present on the surface of the coated cellulose particles.

Hydrophobic agents may include, but are not limited to, low water-soluble organic compounds such as metal soaps, for example, metal myristates, metal stearates, metal palmitates, metal laurates, or other fatty acid derivatives known to those skilled in the art. Other hydrophobic agents may include organic waxes, such as synthetic waxes such as polyethylene or natural waxes such as carnauba wax. Hydrophobic agents that can be used for coating the cellulose particles that can be used for the compositions and methods of the present invention may also be long-chain fatty acids or esters such as stearic acid, oleic acid, castor oil, isododecane, silicones and their derivatives, non-water-soluble polymers such as high molecular weight methylcellulose and ethylcellulose, and high molecular weight water-insoluble fluoropolymers, etc., polymerized silicones or polysiloxanes with the chemical formula [R ₂ SiO] n, wherein R is an organic group such as methyl, ethyl, or phenyl, such as polydimethylsiloxane, polydimethylsiloxane copolyols, polydimethylsiloxane esters; methylsiloxanes and their derivatives. Examples of hydrophobic linear cotton particles useful in the present invention include, but are not limited to, cotton fiber Flock CD60 available from Goonvean Fiber and W200 White Cotton Flock available from International Fiber Corporation.

The hydrophobic cellulose particles of the present invention can be formulated for a variety of "rinse-off" skin care applications.

As used herein, the term "rinse-off" refers to compositions of the present invention that are used in a context whereby the composition is ultimately rinsed or washed from the treated surface (e.g., skin or a hard surface) after or during application of the product. These rinse-off compositions are distinguished from compositions that are applied to the skin and allowed to remain on the skin after application.

The rinse-off compositions comprising cellulose particles of the present invention can be formulated into a wide variety of rinse-off compositions for personal care, including but not limited to liquid cleansers, emulsion cleansers, gel cleansers, soaps, and makeup removers.

The topical cosmetic composition of the present invention may comprise a carrier, which should be a cosmetically and/or pharmaceutically acceptable carrier. The carrier should be suitable for topical application to the skin, should have good aesthetic properties and should be compatible with the other components of the composition.

These product types may comprise several types of cosmetically acceptable topical carriers, including but not limited to solutions, emulsions (e.g., microemulsions and nanoemulsions), gels, solids, and liposomes. The following are non-limiting examples of such carriers. Other carriers can be formulated by one of ordinary skill in the art.

The rinse-off compositions of the present invention preferably comprise at least one cleansing agent selected from the group consisting of fatty acid soaps and synthetic surfactants and/or mixtures of such materials. Optionally, the compositions of the present invention comprise one or more skin conditioning agents. The compositions of the present invention may also comprise one or more skin treating agents. Preferably, the pH of the compositions of the present invention ranges from about 2 to about 11. More preferably, the pH ranges from about 3 to about 10.

The compositions of the present invention may contain saponified fats, such as fatty acid soaps, containing from about 6 to about 22 carbon atoms, preferably from about 8 to about 18 carbon atoms, and more preferably from about 12 to about 18 carbon atoms. Fatty acid soaps having from about 8 to about 18 carbon atoms are preferably present in the compositions of the present invention in an amount of from about 1% to about 60% by weight.

Preferably, the fatty acid soap that can be used in the composition of the present invention is an organic soap obtained using an organic neutralizer, including but not limited to ammonium soap, trialkanolamine soap, aminomethylpropanol soap, aminomethylmalondialdehyde soap and tromethamine soap, more preferably triethanolamine soap and aminomethylpropanol soap.

The synthetic surfactants useful in the compositions of the present invention are preferably synthetic surfactants selected from anionic, nonionic, amphoteric and zwitterionic surfactants. Preferably, they are present in the compositions of the present invention in an amount of from about 1% to about 40%, more preferably from about 1% to about 30%, and most preferably from about 5% to about 30% by weight of the composition.

Amphoteric synthetic surfactants

Amphoteric synthetic detergents can be broadly described as derivatives of aliphatic amines containing long chains having about 8 to 18 carbon atoms and anionic water-solubilizing groups such as carboxyl, sulfo, or sulfate. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate, sodium 3-dodecylaminopropanesulfonate, and dodecyldimethylammonium hexanoate. Other examples of amphoteric and amphoteric surfactants are found in U.S. Patent No. 3,318,817, issued to Cunningham 15 on May 9, 1967, and incorporated herein by reference.

Particularly preferred examples of amphoteric surfactants are those having the following formula:

Zwitterionic synthetic surfactants

Zwitterionic surfactants are broadly described as internally neutralized derivatives of aliphatic quaternary ammonium and tertiary sulfonium compounds, wherein the aliphatic radical may be straight or branched chain, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water-solubilizing group, such as carboxyl, sulfonyl, sulfate, phosphate, or phosphono. Some of these zwitterionic surfactants are described in the following U.S. Patents: 2,129,264; 2,178,353; 2,774,786; 2,813,898; and 2,828,332.

Particularly preferred examples of zwitterionic surfactants are those having the following formula:

Cocamidopropyl Sultaine

Water-soluble betaine surfactants are another example of zwitterionic surfactants useful herein. These materials have the general formula:

Examples of suitable betaine compounds of this type include dodecyldimethylammonium acetate, tetradecyldimethylammonium acetate, hexadecyldimethylammonium acetate, alkyldimethylammonium acetates (wherein the alkyl group has an average length of about 12 to 18 carbon atoms), dodecyldimethylammonium butyrate, tetradecyldimethylammonium butyrate, hexadecyldimethylammonium butyrate, dodecyldimethylammonium hexanoate, hexadecyldimethylammonium hexanoate, tetradecyldimethylammonium valerate, and tetradecyldipropylammonium valerate. Particularly preferred betaine surfactants include dodecyldimethylammonium acetate, dodecyldimethylammonium hexanoate, hexadecyldimethylammonium acetate, and hexadecyldimethylammonium hexanoate.

polymer materials

As used herein, the term "low molecular weight" polymer refers to a polymer having a number average molecular weight ( _Mn ) of about 100,000 or less, as measured by gel permeation chromatography (GPC) calibrated with poly(methyl methacrylate) (PMMA) standards. In certain preferred embodiments, the low molecular weight polymers are those having a molecular weight of about 5,000 to about 80,000 _Mn , more preferably about 10,000 to about 50,000 _Mn , and more preferably between about 15,000 and about 40,000 _Mn .

The polymeric material useful in the compositions of the present invention is preferably a polymeric material suitable for associating anionic and/or amphoteric surfactants therewith and is preferably a non-crosslinked linear acrylic copolymer that can reduce the damage to the impaired skin barrier typically associated with surfactant systems without significantly increasing the viscosity build. The non-crosslinked linear polymer preferably has a relatively low molecular weight, with a number average molecular weight of 100,000 or less as measured by gel permeation chromatography calibrated with poly(methyl methacrylate) (PMMA) standards (as used herein, all number average molecular weights ( _Mn ) refer to molecular weights measured in this manner unless otherwise specified). Thus, the polymeric material acts as a copolymer demulcent. The copolymer demulcent is polymerized from at least two monomeric components. The first monomeric component is selected from one or more α,β-ethylenically unsaturated monomers containing at least one carboxylic acid group. The acid group can be derived from a mono- or di-acid, an anhydride of a di-acid, a monoester of a di-acid, and a salt thereof. The second monomer component is hydrophobically modified (relative to the first monomer component) and is selected from one or more α,β-ethylenically unsaturated non-acid monomers containing _C1 to _C9 alkyl groups, including linear and branched _C1 to _C9 alkyl esters of (meth)acrylates, vinyl esters of linear and branched _C1 to _C10 carboxylic acids, and mixtures thereof. In one aspect of the invention, the second monomer component is represented by the formula:

CH ₂ ＝CRX

wherein R is hydrogen or methyl; X is -C(O) ^OR1 or -OC(O) ^R2 ; ^R1 is a linear or branched _C1 to _C9 alkyl group; and ^R2 is hydrogen or a linear or branched _C1 to _C9 alkyl group. In another aspect of the invention, ^R1 and ^R2 are linear or branched _C1 to _C8 alkyl groups, and in yet another aspect, ^R1 and ^R2 are linear or branched _C2 to _C5 alkyl groups.

Exemplary first monomer components include (meth)acrylic acid, itaconic acid, citraconic acid, maleic acid, fumaric acid, crotonic acid, aconitic acid, and mixtures thereof. Exemplary second monomer components include ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, vinyl formate, vinyl acetate, 1-methylvinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl pivalate, vinyl neodecanoate, and mixtures thereof. As used herein, the terms "(meth)acrylic" acid and "(meth)acrylate" are intended to include the corresponding methyl derivatives of acrylic acid and the corresponding alkyl acrylate. For example, "(meth)acrylic" acid refers to acrylic acid and/or methacrylic acid and "(meth)acrylate" refers to alkyl acrylate and/or alkyl methacrylate.

More preferably, the first monomer component is selected from (meth)acrylic acid, and the second monomer component is selected from at least one _C1 to _{C9 alkyl} (meth)acrylate.

The non-crosslinked, linear acrylic copolymer moderator of the present invention can be synthesized by free radical polymerization techniques known in the art. In one aspect of the present invention, the first monomer component is used in an amount ranging from about 20:80 weight % to about 50:50 weight % relative to the second monomer component, based on the total weight of all monomers in the polymerization reaction medium. In another aspect, the weight ratio of the first monomer component to the second monomer component is about 35:65 weight %, and in yet another aspect, the weight ratio of the first monomer component to the second monomer component is about 25:75 weight %, all based on the total weight of all monomers in the polymerization reaction medium.

On the other hand, emulsion polymerization techniques can be used to synthesize the non-crosslinked linear acrylic copolymer moderators useful in the present invention. In a typical emulsion polymerization, a mixture of the disclosed monomers can be added to a solution of an emulsifying surfactant, such as an anionic surfactant (e.g., a fatty alcohol sulfate or alkyl sulfonate), in a suitable amount of water in a suitable reactor under mixing conditions to prepare a monomer emulsion. The emulsion is deoxygenated by any convenient method (e.g., by sparging with nitrogen), and the polymerization reaction is then initiated by adding a polymerization catalyst (initiator) such as sodium persulfate or any other suitable addition polymerization catalyst known in the emulsion polymerization art. The polymerization medium is agitated until the polymerization reaction is complete, typically for a period of about 4 to about 16 hours. If desired, the monomer emulsion can be heated to a temperature in the range of about 70 to about 95°C before adding the initiator. Unreacted monomer can be eliminated by adding more catalyst, as is known in the emulsion polymerization art. The resulting polymer emulsion product can then be discharged from the reactor and packaged for storage or use. Optionally, the pH or other physical and chemical properties of the emulsion can be adjusted before discharge from the reactor. Typically, the product emulsion has a total solids content in the range of about 10% to about 50% by weight. Typically, the total polymer content (polymer solids) of the product emulsion is in the range of about 15% to about 45% by weight, generally not exceeding about 35% by weight.

In one aspect, the linear copolymer moderators useful in the present invention have a number average molecular weight ( _Mn ) of 100,000 or less as measured by gel permeation chromatography (GPC) calibrated with poly(methyl methacrylate) (PMMA) standards. In another aspect of the invention, the molecular weight ranges from about 5,000 to about 80,000 _Mn , in yet another aspect, from about 10,000 to 50,000 _Mn , and in yet another aspect, from about 15,000 to 40,000 _Mn .

In one aspect of the present invention, the linear copolymer moderator has a viscosity of 500 mPa·s or less (Brookfield RVT, 20 rpm, spindle 1) at a polymer solids concentration of 5 wt % in deionized water and neutralized with an 18 wt % NaOH solution to a pH of 7. In another aspect, the viscosity can be in the range of from about 1 to about 500 mPa·s, in yet another aspect, in the range of from about 10 to about 250 mPa·s, and in another aspect, in the range of from about 15 to about 150 mPa·s.

Preferably, the low molecular weight, non-crosslinked, linear acrylic copolymer is a potassium acrylate copolymer.

Any one of the multiple non-ethoxylated anionic surfactants can be combined with the polymeric material of the present invention to form a cleaning composition according to a preferred embodiment of the present invention.Non-ethoxylated anionic surfactants are surfactants with a negative charge and do not contain any ethoxylated segments, that is to say, there is no -(CCO) _segment on the surfactant. According to certain embodiments, suitable non-ethoxylated anionic surfactants include those selected from the following surfactant types: alkyl sulfates, alkyl sulfonates, alkyl monoglyceride sulfonates, alkyl aryl sulfonates, alkyl sulfosuccinates, alkyl sulfosuccinamates, alkyl carboxylates, fatty alkyl sulfoacetates, alkyl phosphates, acyl glutamates, sarcosinates, taurates, and two or more mixtures thereof. The example of some preferred anionic surfactants includes:

Alkyl sulfate represented by the following formula

R'-CH ₂ OSO ₃ X';

Alkyl monoglyceride sulfate represented by the following formula

Alkyl monoglyceride sulfonate represented by the following formula

Alkyl sulfonate represented by the following formula

R'-SO ₃ X';

Alkyl aryl sulfonate represented by the following formula

Alkyl sulfosuccinate represented by the following formula:

Alkyl phosphates represented by the following formula:

in

R' is an alkyl group having from about 7 to about 22 carbon atoms, and preferably an alkyl group having from about 7 to about 16 carbon atoms,

_R'1 is an alkyl group having from about 1 to about 18 carbon atoms, and preferably an alkyl group having from about 8 to about 14 carbon atoms,

_R'2 is a natural or synthetic 1-amino acid substituent,

X' is selected from the group consisting of alkali metal ions, alkaline earth metal ions, ammonium ions, and ammonium ions substituted with from about 1 to about 3 substituents, each of which may be the same or different, and selected from the group consisting of alkyl groups having from 1 to 4 carbon atoms and hydroxyalkyl groups having from about 2 to about 4 carbon atoms, and

w is an integer from 0 to 20;

and mixtures thereof.

According to certain embodiments shown in patent applications U.S. Serial Nos. 12/822,329 and 12/976,573, the anionic surfactant of the present invention is preferably a non-ethoxylated SO _x anionic surfactant conforming to the following structure:

wherein SO ₃ ⁻ is an anionic hydrophilic group, M ⁺ is a monovalent cation (such as NH ₄ ⁺ , Na ⁺ , K ⁺ , (HOCH ₂ CH ₂ ) ₃ N ^{+ ,} etc.), and R comprises any one of a range of hydrophobic groups and optionally comprises a) a functional group linking the hydrophilic and hydrophobic portions and/or b) an additional hydrophilic group. Examples include:

Alkyl sulfonates , wherein R is equal to C ₆ -C ₂₀ alkyl (linear or branched, saturated or unsaturated), preferably C ₁₀ -C ₁₈ _, and most preferably C ₁₂ -C _17. Specific examples include sodium C ₁₃ -C ₁₇ alkane sulfonate (R = C ₁₃ -C ₁₇ alkyl, M ⁺ =Na ⁺ ) and sodium C ₁₄ -C ₁₇ secondary alkyl sulfonate (R = sC ₁₃ -C ₁₇ alkyl, M ⁺ =Na ⁺ )

· Alpha olefin sulfonates , where R equals

and

R ₁ -CH ₂ -CH＝CH-CH ₂ -

wherein R ₁ =C ₄ -C ₁₆ alkyl or a mixture thereof, preferably C ₆ -C ₁₂ , more preferably C ₈ -C ₁₂ and most preferably C ₁₀ -C _12. Specific examples include sodium C ₁₂ - ₁₄ olefin sulfonate (R ₁ =C ₈ -C ₁₀ alkyl, M ⁺ =Na ⁺ ) and sodium C ₁₄ - ₁₆ olefin sulfonate (R ₁ =C ₁₀ -C ₁₂ alkyl, M ⁺ =Na ⁺ ).

Alkyl sulfate , wherein R ₁ =C ₆ -C ₂₀ ,

R ₁ -O-

(linear or branched, saturated or unsaturated), preferably C ₁₂ -C ₁₈ , more preferably C ₁₂ -C ₁₆ and most preferably C ₁₂ -C _14. Specific examples include ammonium lauryl sulfate (R ₁ = lauryl, C ₁₂ H ₂₅ , M ⁺ = NH ₄ ⁺ ), sodium lauryl sulfate (R ₁ = lauryl, C ₁₂ H ₂₅ , M ⁺ = Na ⁺ ) and sodium cocoyl sulfate (R ₁ = coconut oil alkyl, M ⁺ = Na ⁺ ).

As used herein, the term "amphoteric" refers to: 1) molecules that contain both acidic and basic sites, such as amino acids that contain both amino (basic) and acid (e.g., carboxylic acid, acidic) functional groups; or 2) zwitterionic molecules that have both positive and negative charges within the same molecule. The charge in the latter case may or may not be related to the pH of the composition. Examples of zwitterionic materials include, but are not limited to, alkyl betaines and amidoalkyl betaines, as described above and below. The amphoteric surfactants disclosed herein do not include counterions. Those skilled in the art will readily recognize that, at the pH conditions of the compositions of the present invention, the amphoteric surfactants are electrically neutral by balancing the positive and negative charges, or they have counterions such as alkali metal, alkaline earth metal, or ammonium counterions.

Examples of amphoteric surfactants suitable for use in the present invention include, but are not limited to, amphoteric carboxylates such as alkylamphoacetates (mono or di); alkyl betaines; amidoalkyl betaines; alkyl sulfobetaines; amidoalkyl sulfobetaines; amphoteric phosphates; phosphoimidazolines such as phosphobetaines and pyrophosphobetaines; carboxyalkylalkyl polyamines; alkylimino-dipropionates; alkylampho(mono or di)glycinates; alkylampho(mono or di)propionates; n-alkyl β-aminopropionic acid; alkyl polyaminocarboxylates; and mixtures thereof.

Examples of suitable amphocarboxylate compounds include those represented by the formula:

A-CONH(CH ₂ ) _x N ⁺ R ₅ R ₆ R ₇

in

A is an alkyl or alkenyl group having from about 7 to about 21 carbon atoms (e.g., from about 10 to about 16 carbon atoms);

x is an integer from about 2 to about 6;

_R5 is hydrogen or carboxyalkyl containing from about 2 to about 3 carbon atoms;

_R6 is a hydroxyalkyl group containing about 2 to about 3 carbon atoms or a group represented by the following formula:

R ₈ -O-(CH ₂ ) _n CO ₂ ^-

in

_R8 is an alkylene group having from about 2 to about 3 carbon atoms, and n is 1 or 2; and

_R7 is a carboxyalkyl group containing from about 2 to about 3 carbon atoms;

Examples of suitable alkyl betaines include those of the formula:

BN ⁺ R ₉ R ₁₀ (CH ₂ ) _p CO ₂ ^-

in

B is an alkyl or alkenyl group having from about 8 to about 22 carbon atoms, such as from about 8 to about 16 carbon atoms;

_R9 and _R10 are each independently an alkyl or hydroxyalkyl group having from about 1 to about 4 carbon atoms; and

p is 1 or 2.

A preferred betaine for use in the present invention is lauryl betaine, commercially available as "Empigen BB/J" from Albright & Wilson, Ltd. (West Midlands, United Kingdom).

Examples of suitable amidoalkylbetaines include those of the formula:

D-CO-NH(CH ₂ ) _q -N ⁺ R ₁₁ R ₁₂ (CH ₂ ) _m CO ₂ ^-

in

D is an alkyl or alkenyl group having from about 7 to about 21 carbon atoms, such as from about 7 to about 15 carbon atoms;

R ₁₁ and R ₁₂ are each independently an alkyl group having from about 1 to about 4 carbon atoms.

or

hydroxyalkyl;

q is an integer from about 2 to about 6; and m is 1 or 2.

One amidoalkyl betaine is cocamidopropyl betaine, which is commercially available under the trade designation "Tegobetaine L7" from Goldschmidt Chemical Corporation (Hopewell, Virginia).

Examples of suitable amidoalkylsulfobetaines include those of the formula:

in

E is an alkyl or alkenyl group having from about 7 to about 21 carbon atoms, such as from about 7 to about 15 carbon atoms;

R ₁₄ and R ₁₅ are each independently an alkyl or hydroxyalkyl group having from about 1 to about 4 carbon atoms;

r is an integer from about 2 to about 6; and

R ₁₃ is a methyl group having about 2 to about 3 carbon atoms.

Alkylene or hydroxyalkylene;

In one embodiment, the amidoalkyl sultaine is cocamidopropyl hydroxysultaine, which is commercially available under the trade designation "Mirataine CBS" from Rhone-Poulenc Inc. (Cranbury, New Jersey).

Examples of suitable amphoteric phosphate compounds include those represented by the following formula:

in

G is an alkyl or alkenyl group having from about 7 to about 21 carbon atoms, such as from about 7 to about 15 carbon atoms;

s is an integer from about 2 to about 6;

R ₁₆ is hydrogen or carboxyalkyl containing from about 2 to about 3 carbon atoms;

R ₁₇ is a hydroxyalkyl group containing about 2 to about 3 carbon atoms or a group represented by the following formula:

R ₁₉ -O-(CH ₂ ) _t -CO ₂ ^-

wherein R ₁₉ is an alkylene or hydroxyalkylene group having from about 2 to about 3 carbon atoms and t is 1 or 2; and

R ₁₈ is an alkylene or hydroxyalkylene group having about 2 to about 3 carbon atoms.

In one embodiment, the amphoteric phosphate compound is sodium lauroamphoacetate phosphate, commercially available under the trade designation "Monateric 1023" from Mona Industries (Paterson, New Jersey), and those disclosed in US Patent No. 4,380,637, which is incorporated herein by reference.

Examples of suitable phosphobetaines include those represented by the formula:

wherein E, r, R ₁ , R ₂ and R ₃ are as defined above. In one embodiment, the phosphobetaine compounds are those disclosed in US Patents 4,215,064, 4,617,414 and 4,233,192, all of which are incorporated herein by reference.

Examples of suitable pyrophosphobetaines include those compounds represented by the formula:

wherein E, r, R ₁ , R ₂ and R ₃ are as defined above. In one embodiment, the pyrophosphobetaine compounds are those disclosed in US Patent Nos. 4,382,036, 4,372,869 and 4,617,414, all of which are incorporated herein by reference.

Examples of suitable carboxyalkylalkyl polyamines include those compounds represented by the formula:

in

I is an alkyl or alkenyl group containing from about 8 to about 22 carbon atoms (e.g., from about 8 to about 16 carbon atoms);

R ₂₂ is a carboxyalkyl group having from about 2 to about 3 carbon atoms;

R ₂₁ is an alkylene group having about 2 to about 3 carbon atoms and

u is an integer from about 1 to about 4.

Any suitable amount of polymeric material and surfactant can be used consistently with the compositions and methods of the present invention. In certain preferred embodiments, the compositions of the present invention may comprise a polymeric material greater than zero to about 6 weight percent (based on the active amount of the polymeric material in the total composition weight). In certain more preferred embodiments, the composition comprises a polymeric material of approximately 0.1 to approximately 4.5 weight percents, more preferably a polymeric material of approximately 0.1 to approximately 3.5 weight percents, and even more preferably a polymeric material of approximately 0.2 to approximately 2.5 weight percents. With regard to the cleaning compositions comprising the amphoteric blend that is substantially free of anionic surfactants, the polymeric material should exist with an amount between approximately 0.03 and approximately 2.1 weight percents of the composition, wherein the composition does not comprise coco-betaine. Wherein coco-betaine exists as a surfactant, and should exist in the composition in an amount less than approximately 0.03 weight percent or more than approximately 1.6 weight percents of the polymeric material.

In certain preferred embodiments, the compositions of the present invention comprise from about 0.0015 to about 15 weight percent surfactant, based on the total active amount of surfactant in the total weight of the composition. In certain more preferred embodiments, the compositions comprise from about 2 to about 12 weight percent total surfactant. Preferred embodiment formulations have from about 2 to about 9 weight percent total surfactant. Preferred embodiments have from about 2 to about 7 weight percent total surfactant. Where coco betaine is present, it should be present in the composition in an amount less than about 0.065 weight percent or greater than about 3.5 weight percent.

When formulating the compositions of the present invention, when the ratio of non-ethoxylated anionic surfactant to amphoteric surfactant is less than 0.5, the pH of the composition should be between 4.8 and about 6. When the ratio of non-ethoxylated anionic surfactant to amphoteric surfactant is greater than 0.5, the pH of the composition should be less than or equal to 6, preferably between 2.5 and 6.

Non-crosslinked, straight chain acrylic copolymers that can be used for the present composition can also be synthesized by free radical polymerization techniques known in the art. In one aspect of the invention, the first monomer component used is in an amount ranging from about 20:80 wt % to about 50:50 wt % relative to the amount of the second monomer component, based on the total weight of all monomers in the polymerization medium. On the other hand, the weight ratio of the first monomer component to the second monomer component is about 35:65 wt %, and in yet another aspect, the weight ratio of the first monomer component to the second monomer component is about 25:75 wt %, all weight percentages being based on the total weight of all monomers in the polymerization medium.

The resulting cleaning compositions, as well as any compositions comprising a polymeric material and a surfactant component having at least one non-ethoxylated anionic surfactant and at least one amphoteric surfactant combined in the combining step of the method according to the present invention, may also comprise any of a variety of other components, including, but not exclusively, additives that enhance the appearance, feel and fragrance of the composition, such as colorants, fragrances, preservatives, pH adjusters, and the like.

Any of a variety of nonionic surfactants are suitable for use in the compositions of the present invention, keeping in mind that the surfactant loading should not exceed about 14 weight percent of the compositions described herein. Examples of suitable nonionic surfactants include, but are not limited to, fatty alcohol acid or amide ethoxylates, monoglyceride ethoxylates, sorbitan ester ethoxylates, alkyl polyglucosides, polyglycerol esters, mixtures thereof, and the like. Certain preferred nonionic surfactants include alkyl polyglucosides such as, but not limited to, cocoyl glucoside and decyl glucoside, and polyglycerol esters such as, but not limited to, polyglyceryl-10 laurate and polyglyceryl-10 oleate.

Any of a variety of commercially available secondary conditioning agents that impart other properties to hair, such as shine, such as volatile silicones, are suitable for use herein. In one embodiment, the volatile silicone conditioning agent has an atmospheric boiling point of less than about 220° C. The volatile silicone conditioning agent may be present in an amount from about 0 percent to about 3 percent, such as from about 0.25 percent to about 2.5 percent or from about 0.5 percent to about 1 percent, based on the total weight of the composition. Examples of suitable volatile silicones include, but are not limited to, polydimethylsiloxane, polydimethylcyclosiloxane, hexamethyldisiloxane, cyclomethicone fluids such as polydimethylcyclosiloxane commercially available under the trade designation “DC-345” from Dow Corning Corporation (Midland, Michigan), and mixtures thereof, and preferably include cyclomethicone fluids.

Any of a variety of commercially available humectants that can provide moisturizing and conditioning properties to personal cleansing compositions are suitable for use in the present invention. The humectant can be present in an amount of from about 0 percent to about 10 percent (e.g., from about 0.5 percent to about 5 percent or from about 0.5 percent to about 3 percent), based on the total weight of the composition. Examples of suitable humectants include, but are not limited to: 1) a water-soluble liquid polyol selected from the group consisting of glycerol, propylene glycol, hexylene glycol, butylene glycol, dipropylene glycol, and mixtures thereof; 2) a polyalkylene glycol having the formula: HO-(R"O) _b -H, wherein R" is an alkylene group having from about 2 to about 3 carbon atoms and b is an integer from about 2 to about 10; 3) a polyethylene glycol ether of _methyl glucose having _the formula _CH3 - _C6H10O5- ( _OCH2CH2 ) _c - _OH , wherein c is an integer from about 5 to about 25; 4) urea; and 5) mixtures thereof, with glycerol being a preferred humectant.

Examples of suitable chelating agents include those that are capable of protecting and preserving the compositions of the present invention. These chelating agents are preferably ethylenediaminetetraacetic acid ("EDTA"), and more preferably tetrasodium EDTA, commercially available under the trade name "Versene 100XL" from Dow Chemical Company (Midland, Michigan), and are present in an amount of from about 0% to about 0.5 percent or from about 0.05 percent to about 0.25 percent, based on the total weight of the composition.

Suitable preservatives include organic acid preservatives, which may include benzoic acid and its alkali metal and ammonium salts (e.g., sodium benzoate), sorbic acid and its alkali metal and ammonium salts (e.g., potassium sorbate), p-anisic acid and its alkali metal and ammonium salts, and salicylic acid and its alkali metal and ammonium salts. The pH of the composition may be adjusted to a suitable acid value using any cosmetically acceptable organic or inorganic acid, such as citric acid, acetic acid, glycolic acid, lactic acid, malic acid, tartaric acid, or hydrochloric acid.

In one embodiment of the composition, the content of sodium benzoate in the composition is about 0 to about 0.5 percent, based on the total weight of the composition. In another embodiment, the content of potassium sorbate in the composition is about 0 to about 0.6 percent, more preferably about 0.3 to about 0.5 percent, based on the total weight of the composition.

The method of the present invention may further comprise any of a number of steps to mix one or more of the above-mentioned optional components with or introduce them into the composition comprising the polymeric material before, after, or during the above-mentioned combining step. Although in certain embodiments, the order of mixing is not critical, in other embodiments it is preferred to premix certain components (e.g., fragrance and nonionic surfactant) prior to adding such components to the composition comprising the polymeric material and/or anionic surfactant.

The cleansing methods of the present invention may further comprise any of a number of additional optional steps commonly associated with cleansing hair and skin including, for example, lathering, rinsing steps, and the like.

The above information regarding low molecular weight hydrophobically modified polymers and compositions useful in the methods of the present invention is described in US 7,803,403, US 2006/0257348, and US 20070111910, all of which are hereby incorporated by reference herein.

The methods and compositions of the present invention disclosed herein in an exemplary manner may be implemented in the absence of any component, ingredient, or step not specifically disclosed herein. Several examples are shown below to further illustrate the essence of the present invention and the manner in which the present invention is implemented. However, the present invention should not be considered to be limited to its details.

Topical rinse-off compositions useful in the compositions of the present invention can be formulated as solutions. These solutions typically comprise an aqueous solvent (e.g., from about 50% to about 99.99%, or from about 90% to about 99% of a cosmetically acceptable aqueous solvent).

The topical compositions useful in the present invention can be formulated as solutions containing an emollient. Such compositions preferably contain from about 2% to about 50% of one or more emollients. As used herein, "emollient" refers to a substance used to prevent or relieve dryness, as well as to protect the skin. A wide variety of suitable emollients are known and can be used herein. Sagarin, Cosmetics, Science and Technology, 2nd edition, Vol. 1, pp. 32-43 (1972); Wenninger and McEwen, International Cosmetic Ingredient Dictionary and Handbook, pp. 1656-61, 1626, and 1654-55 (The Cosmetic, Toiletry, and Fragrance Assoc., Washington, D.C., 7th edition, 1997) (hereinafter referred to as the "ICI Handbook") contain numerous examples of suitable materials.

Preferably, the rinse-off compositions of the present invention comprise from about 1% to about 20% (e.g., from about 5% to about 10%) emollient and from about 50% to about 90% (e.g., from about 60% to about 80%) water.

The topical compositions useful in the present invention can be formulated as solutions containing an emulsifier. Such compositions preferably contain from about 0.1% to about 1% emulsifier. The emulsifier can be nonionic, anionic, or cationic. Suitable emulsifiers are disclosed, for example, in U.S. Patent No. 3,755,560, U.S. Patent No. 4,421,769, McCutcheon's Detergents and Emulsifiers, North American Edition, pp. 317-324 (1986), and the ICI Handbook, pp. 1673-1686.

Another type of product that can also be formulated from a solution is a cream cleanser. Cream cleansers preferably contain from about 5% to about 50% (e.g., from about 10% to about 20%) of an emollient and from about 45% to about 85% (e.g., from about 50% to about 75%) of water.

The topical compositions useful in the present invention can be formulated as emulsions. If the carrier is an emulsion, about 1% to about 10% (e.g., about 2% to about 5%) of the carrier comprises an emulsifier. The emulsifier can be nonionic, anionic, or cationic. Suitable emulsifiers are disclosed, for example, in U.S. Patent No. 3,755,560, U.S. Patent No. 4,421,769, McCutcheon's Detergents and Emulsifiers, North American Edition, pp. 317-324 (1986), and the ICI Handbook, pp. 1673-1686.

The topical rinse-off compositions of the present invention can also be formulated as lotions. Typically, such lotions contain from 0.5% to about 5% of an emulsifier. Such creams typically contain from about 1% to about 20% (e.g., from about 5% to about 10%) of an emollient; from about 20% to about 80% (e.g., from 30% to about 70%) of water; and from about 1% to about 10% (e.g., from about 2% to about 5%) of one or more emulsifiers.

Oil-in-water and water-in-oil single emulsion skin care formulations, such as lotions and creams, are well known in the cosmetics field and can be used in the present invention. Multiphase emulsion compositions (such as water-in-oil-in-water types, as disclosed in U.S. Patents 4,254,105 and 4,960,764) can also be used in the present invention. Typically, such single-phase or multiphase emulsions contain water, an emollient, and an emulsifier as their essential ingredients.

The topical compositions of the present invention can also be formulated into gels (e.g., using a suitable gelling agent to form a hydrogel). Suitable gelling agents for hydrogels include, but are not limited to, natural gums, acrylic acid and acrylate polymers and copolymers, and cellulose derivatives (e.g., hydroxymethylcellulose and hydroxypropylcellulose). Suitable gelling agents for oils (e.g., mineral oil) include, but are not limited to, hydrogenated butylene/ethylene/styrene copolymers and hydrogenated ethylene/propylene/styrene copolymers. Such gels typically contain between about 0.1% and 5% by weight of such a gelling agent.

The topical rinse-off compositions of the present invention may also be formulated as suspensions. In such cases, the compositions of the present invention preferably include a suspending agent. As used herein, the term "suspending agent" refers to any material known or otherwise effective to provide suspending, gelling, viscosifying, solidifying, and/or thickening properties to a composition or otherwise provide structure to the final product form. Such suspending agents include gelling agents and polymeric or non-polymeric or inorganic thickening or tackifying agents. Such materials will generally be solid under ambient conditions and include organic solids, silicone solids, crystalline or other gelling agents, inorganic particulates such as clay or silica, or combinations thereof.

The concentration and type of suspending agent selected for use in the topical leave-on compositions of the present invention will vary depending on the desired product hardness, rheological properties, and/or other relevant product characteristics. For most suspending agents suitable for use herein, the total concentration is in the range of about 0.1% to about 40%, more typically in the range of about 0.1% to about 35%, by weight of the composition. For liquid embodiments (e.g., pressurized or other liquid sprays, rollerballs, etc.), the suspending agent concentration will tend to be lower, and for semi-solid (e.g., soft solids or creams) or solid cleanser embodiments, the suspending agent concentration will tend to be higher. Preferably, the suspending agent is present in the compositions of the present invention in an amount of about 0.1% to about 40%, more preferably, the suspending agent is present in an amount of about 0.1% to about 30%.

Non-limiting examples of suitable suspending agents include hydrogenated castor oil (e.g., castor wax MP80, castor wax, etc.), fatty alcohols (e.g., stearyl alcohol), paraffin waxes, triglycerides and other similar solid suspending esters or other microcrystalline waxes, silicones and modified silicone waxes. Non-limiting examples of optional suspending agents suitable for use herein are described in U.S. Pat. No. 5,976,514 (Guskey et al.), U.S. Pat. No. 5,891,424 (Bretzler et al.), which are incorporated herein by reference.

Other suitable suspending agents include silicone elastomers at concentrations ranging from about 0.1% to about 10% by weight of the composition. Non-limiting examples of such silicone elastomeric materials suitable for use as suspending agents herein are described in U.S. Patent No. 5,654,362 (Schulz, Jr. et al.); U.S. Patent No. 6,060,546 (Powell et al.); and U.S. Patent No. 5,919,437 (Lee et al.), which descriptions are incorporated herein by reference. These silicone elastomeric materials may also be added solely for their skin feel or other cosmetic benefits, or for such benefits in combination with the benefits of a suspending agent.

The topical compositions of the present invention may also be formulated as solid dosage forms (eg, wax-based sticks, soap bar compositions, powders, or wipes containing powders).

In addition to the foregoing components, the topical compositions useful in the subject invention may also contain a wide variety of additional oil-soluble and/or water-soluble materials conventionally used in compositions for application to the skin, hair, and nails at their art-established levels.

Additional cosmetic active agents

In one embodiment, the topical composition further comprises another cosmetic active agent in addition to the cellulose particles. By "cosmetic active agent" is meant a compound that has a cosmetic or therapeutic effect on the skin, hair, or nails, for example, lightening agents, darkening agents such as self-tanning agents, anti-acne agents, shine control agents, antimicrobial agents, anti-inflammatory agents, antifungal agents, antiparasitic agents, external analgesics, sunscreens, photoprotectants, antioxidants, keratolytic agents, detergents/surfactants, moisturizers, nutrients, vitamins, energy enhancers, antiperspirants, astringents, deodorants, hair removers, firming agents, anti-callus agents, and agents for conditioning hair, nails, and/or skin.

In one embodiment, the agent is selected from, but not limited to, the group consisting of: hydroxy acids, benzoyl peroxide, resorcinol sulfur, ascorbic acid, D-panthenol, hydroquinone, octyl methoxycinnamate, titanium dioxide, octyl salicylate, homosalate, avobenzone, polyphenols, carotenoids, free radical scavengers, spin traps, retinoids such as retinol and retinyl palmitate, ceramides, polyunsaturated fatty acids, essential fatty acids, enzymes, enzyme inhibitors, minerals, hormones such as estrogen, such as hydrogenated Cortisone steroids, 2-dimethylaminoethanol, copper salts such as copper chloride, copper-containing peptides such as Cu:Gly-His-Lys, coenzyme Q10, peptides such as those disclosed in U.S. Patent 6,620,419, lipoic acid, amino acids such as proline and tyrosine, vitamins, lactobionic acid, acetyl-CoA, niacin, riboflavin, thiamine, ribose, electron transporters such as NADH and FADH2, and other plant extracts such as aloe vera, and their derivatives and mixtures. The cosmetic active agent will generally be present in the composition of the present invention in an amount of from about 0.001% to about 20%, for example from about 0.01% to about 10%, such as from about 0.1% to about 5%, by weight of the composition.

Examples of vitamins include, but are not limited to, vitamin A, B vitamins (such as vitamin B3, vitamin B5, and vitamin B12), vitamin C, vitamin K, and vitamin E, and derivatives thereof.

Examples of hydroxy acids include, but are not limited to, glycolic acid, lactic acid, malic acid, salicylic acid, citric acid, tartaric acid, and the like.

Examples of antioxidants include, but are not limited to, water-soluble antioxidants such as sulfhydryl compounds and their derivatives (e.g., sodium metabisulfite and N-acetylcysteine), lipoic acid and dihydrolipoic acid, resveratrol, lactoferrin, and ascorbic acid and ascorbic acid derivatives (e.g., ascorbyl palmitate and ascorbyl polypeptide). Oil-soluble antioxidants suitable for use in the compositions of the present invention include, but are not limited to, butylated hydroxytoluene, retinoids (e.g., retinol and retinyl palmitate), tocopherols (e.g., tocopherol ethyl ester), tocotrienols, and ubiquinone. Natural extracts containing antioxidants suitable for use in the compositions of the present invention include, but are not limited to, extracts containing flavonoids and isoflavones and their derivatives (e.g., genistein and di-zein), extracts containing resveratrol, and the like. Examples of such natural extracts include grape seed, green tea, pine bark, and propolis. Other examples of antioxidants can be found in the ICI Handbook, pages 1612-13.

Other materials

Various other materials may also be present in the compositions of the present invention. These include wetting agents, proteins and polypeptides, preservatives, and alkaline agents. Examples of such agents are disclosed in the ICI Handbook, pages 1650-1667.

The compositions of the present invention may also contain chelating agents (e.g., EDTA) and preservatives (e.g., parabens). Examples of suitable preservatives and chelating agents are listed in the ICI Handbook on pages 1626 and 1654-55. In addition, the topical compositions useful herein may contain conventional cosmetic adjuvants such as dyes, sunscreens (e.g., titanium dioxide), pigments, and fragrances.

It has been found that the hydrophobic cellulose particles useful in the compositions of the present invention have excellent water and oil absorption properties. It is believed that the compositions of the present invention contain hydrophobic cellulose particles that absorb excess sebum from the skin, thereby reducing skin radiance. It is also believed that the compositions of the present invention protect the skin barrier by forming a hydrophobic layer on the skin surface and preventing the penetration of surfactants, emulsifiers, or other potentially irritating ingredients. In addition, this hydrophobic layer formed on the skin surface should reduce transepithelial water loss and increase skin hydration. However, in some cases, it may be desirable for the cellulose particles to have enhanced or reduced hydrophobic or hydrophilic properties.

Therefore, the hydrophobic cellulose particles useful in the compositions of the present invention may be treated with additional hydrophobic or hydrophilic agents to further enhance the hydrophobic and/or hydrophilic properties, respectively, as desired. Hydrophobic agents may include, but are not limited to, low water-soluble organic compounds such as long-chain fatty acids or esters, such as stearic acid, oleic acid, castor oil, isododecane, silicones, and their derivatives; water-insoluble polymers such as high molecular weight methylcellulose and ethylcellulose; and high molecular weight water-insoluble fluoropolymers; polymeric silicones or polysiloxanes having the chemical formula [R2SiO]n, wherein R is an organic group such as methyl, ethyl, or phenyl, such as polydimethylsiloxane, polydimethylsiloxane copolyols, polydimethylsiloxane esters; methylsiloxanes, and their derivatives. Hydrophilic agents such as water-soluble polymers, for example, low molecular weight methylcellulose or hydroxypropylmethylcellulose (PMC); sugars, for example monosaccharides such as fructose and glucose, disaccharides such as lactose, sucrose, or polysaccharides such as cellulose, amylose, dextran, etc., as well as low molecular weight polyvinyl alcohol and silica hydrates can also be used to enhance the hydrophilic properties of the cellulose particles used in the compositions of the present invention.

The texture of compositions formulated with the hydrophobic linear cellulose particles of the present invention has also been found to be "soft," silky, and soft, and aesthetically pleasing to the touch during and after application. As used herein, the term "soft" refers to the bulk density of the hydrophobic linear cellulose particles useful in the compositions of the present invention. The bulk density of the hydrophobic linear cellulose particles useful in the compositions of the present invention is preferably from about 0.1 to about 2 (g/cm ³ ), more preferably from about 0.15 to about 1.8 g/cm ³ and most preferably from about 0.15 to about 1.6 g/cm ³ . Preferably, the cellulose particles useful in the compositions of the present invention are present in the composition in an amount of from about 1% to about 20% by weight of the composition, more preferably from about 1% to about 10% by weight of the composition and most preferably from about 1% to about 6% by weight of the composition.

Methods of cleansing and conditioning skin or hair

The methods of the present invention also relate to methods for cleansing and conditioning skin or hair using the personal cleansing products of the present invention. These methods comprise the steps of wetting a substantially dry, disposable, single-use personal cleansing product with water, the cleansing product comprising a water-insoluble base, a lathering surfactant, and a conditioning component, and contacting the skin or hair with the wetted product. In further embodiments, the methods and compositions of the present invention can also be used to deliver various active ingredients to the skin or hair.

The compositions of the present invention can be substantially dry and wetted with water before use. The product can be wetted by immersing it in a water-filled container or placing it under a stream of water. Foam can be generated from the product by mechanical agitation and/or deformation of the product before or during contact with the skin or hair. The resulting foam can be used to cleanse and condition the skin or hair. During the cleansing process and subsequent rinsing with water, the conditioning agent and active ingredient are deposited on the skin or hair. The physical contact of the substrate with the skin or hair enhances the deposition of the conditioning agent and active ingredient.

The present invention will be further described by reference to the following examples in order to further illustrate the present invention and its advantages. These examples are not intended to be limiting but illustrative.

Unless otherwise mentioned, compounds are indicated by their CTFA name or their chemical name, as the case may be, and percentages are given on a weight basis.

Example 1: Characterization of hydrophobic and hydrophilic linear cellulose fibers

The hydrophobic cotton particles and hydrophilic cotton particles listed in Table 1 below are characterized as follows:

Material :

Table 1

Material Squalene Deionized water Hydrophobic linear cotton particles (available from Goonvean, Cornwall England) Hydrophobic particles #1 Hydrophobic linear cotton particles (purchased from IFC in North Tonawanda, NY) Hydrophobic particles #2 Hydrophilic cotton particles (purchased from Resources of Nature in South Plainfield, NJ) Hydrophilic particles #1

Example 1A: Particle size measurement :

The particle size of the cellulosic material was determined by the Mie/Fraunhofer laser light scattering method using a Malvern Hydro 2000S particle size analyzer by the following procedure:

1. Make sure the unit window and lens are clean and free of scratches.

2. Rinse (with deionized water) and drain the accessory at least 2 times to eliminate any contamination from previous samples.

3. Turn off the pump/stirrer and turn on the ultrasonic welding for 30 seconds to allow air bubbles to dissipate.

4. Fill the dispersion unit with deionized water. Adjust the pump/stirrer speed to 2100 rpm, then turn off the pump for approximately 3 seconds to allow the air to dissipate. Then slowly increase the pump back to 2100 rpm. Top up the dispersion unit with water to replace the volume of air displaced.

5. Add 4 drops of 5% IGEPAL CA 630 (non-ionic detergent) to the cell and allow it to disperse before measuring the background. If this concentration causes bubbles to form, clean the cell with 2 drops of surfactant and repeat the procedure. Ensure that the background gives a clean value. Follow the 2-150 and 20-20 rules (the first two detectors should have a light intensity of less than 150 units and the 20th detector should have a light intensity of less than 20 units).

6. When the system is clean, add the diluted sample to be measured to the dispersion unit in an amount of approximately 2 mg in 10 g of water.

7. Start measuring when the obstruction caused by particles in the sample is 2% to 5%. Note that D50 and D90 are measured in microns. (D50 means 50% of the particles are smaller than this value; D90 means 50% of the particles are smaller than this value)

8. Repeat the experiment three times and record the average of the three results as the final value.

The average particle size of the various cellulose particles summarized in Table 1 was determined and is shown in Table 2.

Table 2

Example 1B: Contact Angle

The contact angles of the various cellulose particles summarized in Table 1 were determined as follows:

40 grams of the cotton particles shown in Table 1 were placed in a particle sample holder; the surface was pressed with consistent force to produce a smooth and compacted particle surface. A 500 μl microsyringe filled with the test liquid (water) with a 0.52 mm needle was used to dispense and deposit a 5 μl droplet on the surface. The contact angle of the droplet on each cotton particle sample was measured and calculated from three replicate tests on each sample using a DataPhysics video-based optical contact angle measurement system OCA 20 with SCA20 software. The results are shown in Table 3.

Table 3

Material Initial water contact angle (degrees) Hydrophobic linear cotton particles (#2) 136.2(5.8)* Hydrophilic cotton particles 39.1(4)* Hydrophobic linear cotton particles (#1) 122.3(3.2)*

* represents standard deviation

As shown in Table 3, the hydrophobic cotton particles exhibited a larger water contact angle than the hydrophilic cotton particles.

Example 1C: Infrared Spectrum :

Infrared spectroscopy was performed on three cotton particles as follows:

Solvent extraction of the cotton material was carried out using dichloromethane, after which IR analysis of the evaporation residue was carried out and is shown in the accompanying Figures 1 and 2.

The spectra (shown in Figures 1 and 2) show the extraction residues from two hydrophobic linear cotton particles (#2 and #1) as well as a polydimethylsiloxane reference spectrum.

Solvent extracts of the two hydrophobic cotton materials (#2 and #1) showed a significant amount of waxy semi-solid residue and a relatively small amount from the hydrophilic cotton material. It is believed that this waxy semi-solid residue coating is responsible for the hydrophobic nature of the two hydrophobic cotton particles.

Infrared analysis of the hydrophobic cotton residues #2 and #1 showed that they both contained silicone (polydimethylsiloxane or related polymers) and other components. The #2 residue included long-chain hydrocarbon wax-like materials (as indicated by split peaks at approximately 1375 and 725 cm-1), while the #1 residue included ester components (as indicated by IR peaks at approximately 1735 and 1250 cm-1).

The hydrophilic cotton particles (Virgin Cotton Flock) showed negligible separated residue. The morphology of this material was significantly different from the other two materials, indicating a higher degree of processing that reduced most of the cotton fibers to a fine powder material. The hydrophilic nature of this material is likely due to the inherent absorbent properties of cotton and the lack of a repellent finish.

Furthermore, infrared analysis showed that all three cotton materials were typical "cellulosic" materials. Characterization of the three different cotton materials showed that the hydrophobicity (#2 and #1) was composed of a silicone-based hydrophobic treatment. In contrast, the hydrophilic cotton lacked a silicone-based hydrophobic repellent treatment.

Example 2: Specific surface area

Inverse gas chromatography (IGC) has been reported in various papers as a good method for determining isotherms at limited concentrations and ambient temperature using organic probe molecules. (Thielmann, F., Burnett, D.J., and Heng, J.Y.Y. (2007) Determination of the surface energy distributions of different processed lactose. Drug Dev. Ind. Pharm. 33, 1240-1253. See also Yla-Maihaniemi, P.P. et al. (2008) Inverse gas chromatographic method for measuring the dispersive surface energy distribution for particulates. Langmuir, 24, pp. 9551-9557.

The specific surface area was determined using IGC using octane by measuring the octane adsorption isotherm at 30°C and 0% RH. The results of these measurements are shown in Table 4. "BET" is a measure of specific surface area known to those skilled in the art.

Table 4

Specific surface area of particles (BET/IGC)

sample Hydrophilic cotton particles 1.4 Hydrophobic linear cotton particles (#1) 1.23 Hydrophobic linear cotton particles (#2) 1.6

Example 3: Absorption capacity and retention

The olive oil absorption capacity of the dry cotton particles in Table 1 was measured under standard conditions (ie, ambient temperature and pressure). The saturated particles were also subjected to centrifugal forces to measure their retention capacity.

When a porous medium containing a liquid is subjected to a force, the liquid gradually empties from the large pores and then, as the pressure increases, increasingly empties from the small pores. A medium containing a high pore volume distribution of small pores (or effective pores) can hold more liquid at higher confinement, and this retention can be a useful characteristic when it is desired that the medium act as a liquid retainer (a sponge effect).

To evaluate the retention of the particles, the supersaturated oil/particle combination was subjected to centrifugal force (8000 rpm, 300 seconds) and the remaining oil was measured. The results of this measurement are shown in Table 5.

After acceleration, the remaining oil can be expressed as a ratio of the amount of saturated oil (=mass of remaining oil/mass of initial oil in the blend) or the remaining oil amount can be expressed as a mass fraction of the particle/oil mixture (=mass of remaining oil/mass of particle/oil composite). Both calculations provide different insights and are shown in the table below.

Table 5

Absorption and retention of triolein (olive oil) by cotton particles

The two hydrophobic linear cotton particles (#1 and #2) exhibited very high oil absorption in a dry, loosely packed state. In addition, the hydrophobic linear cotton particle (#1) retained a large amount of triglycerides even under applied acceleration.

Example 4: Oil absorption speed

The oil absorption rate of a material can be determined by the following procedure:

A 6 x 4 cm rectangular template was cut from 0.25 mm thick paper. A 4 x 2 cm rectangular window was cut in the middle, with 1 cm of paper surrounding the edge of the window. A glass microscope slide was weighed and its mass recorded. The template was placed on the slide and the test material was dispensed into the window of the template. The material was spread over the entire window with a metal spatula to produce a flat rectangular layer with a mass of 0.24 g (± 0.01 g). The template was carefully removed, the edges of the slide were cleaned off with a spatula or a gloved fingertip as needed, and the mass of the slide + material was recorded. The slide (with the oil-absorbing granular layer) was placed flat in an incubator at 32°C. 0.0858 g of the sebum component of interest was dispensed onto the slide, on one side of the granular layer, and in contact with the granular layer, using a 0-100 μL pipette (liquid). (For squalene, 100 μL was used; for triolein, 94.3 μL was used based on the density indicated by the supplier). The slides were placed in an incubator for 15 seconds (for subsequent testing). A timer was started upon dispensing the droplet. After 15 seconds, the slides were removed from the incubator and any unabsorbed sebum components were carefully wiped from the slides using a Kimwipe. The slides were weighed to determine the amount of sebum components absorbed by the particles during the absorption period. The above steps were repeated for each slide, with each sebum component/particle combination tested in at least three replicates. A ratio was calculated to show the mass of sebum component absorbed per mass of oil-absorbing particles in 15 seconds. The results of this measurement are shown in the accompanying Figure 3.

FIG3 shows that the cotton particles (#1 cotton particles) absorb both squalene and triglycerides much faster than the hydrophilic cotton particles.

Example 5: Water absorption speed

The water absorption rate of a material is determined by the following procedure:

The gravimetric absorption test (GAT) method was used to determine the water absorption kinetics of hydrophobic cotton particles relative to hydrophilic cotton particles. Cotton particle samples were loaded into a small cylindrical container and water was introduced into contact with the cotton particles through a graduated water reservoir. The change in water weight caused by water transfer or absorption by the cotton particles was electronically recorded by a computer during the study. The absorption rate was calculated and plotted for different cotton particle samples.

As shown in FIG4 , the hydrophobic cotton particles have a slower water absorption rate than the hydrophilic cotton particles.

Example 6: Water and oil absorption capacity

The water and oil absorption capacities of the materials were determined by the following procedures as set forth below in Examples 6A and 6B.

Each experiment was repeated three times for #1 hydrophobic cotton particles, hydrophilic cotton particles (#1), and #2 hydrophobic cotton particles.

Example 6A: Measurement of hydrophobicity and oil absorption .

The measuring instrument is tared with the particle sample. Squalene is then added dropwise through a disposable pipette until the sample appears almost saturated. A metal spatula is used to thoroughly mix the oil and particles until saturated. (After mixing, the spatula is wiped clean against the side of the weighing boat to ensure that there is no loss of material). As used herein, "saturated" is defined as the mixture being able to retain all available squalene so that the bottom of the boat appears dry. This determination is based on the appearance of the mixture and the condition of the weighing boat. The total grams of squalene are recorded and the relative oil absorption ratio is calculated by dividing the total weight of the oil by the total weight of the cotton material. The results of this process are shown in the attached Figure 5.

Example 6B: Measurement of water absorption

The water absorption was measured following a method similar to that described in Example 6A, but using water instead of the oil material. The results of this test are shown in FIG6 .

Example 7: Cleaning composition

Table 6 :

The cleaning compositions of the present invention shown in Table 6 above were prepared according to the above procedure:

1. Add water to container and begin mixing.

2. Add Acrylates Copolymer or Acrylates/ _C10-30 Alkyl Acrylate Crosspolymer or Carbomer or Xanthan Gum to the container and mix until fully dispersed.

3. Neutralize the carbomer with sodium hydroxide.

4. Add sodium laureth sulfate and/or decyl glucoside and/or lauryl glucoside and/or ammonium laureth sulfate to the container.

5. Add Cocamidopropyl Betaine (pre-dispersed salicylic acid in Cocamidopropyl Betaine if desired) and/or Cocamide MEA and/or Glycereth-7 and/or PPG-2 Hydroxyethyl Cocamide and/or PEG-16 Soy Sterol and/or PEG-120 Methyl Glucose Dioleate to the container.

6. Add PEG-80 Sorbitan Laurate and/or Cocamidopropyl PG Dimonium Chloride Phosphate and/or Sodium C14-16 Olefin Sulfonate and/or Disodium Lauroamphodiacetate and/or Sodium Cocoyl Sarcosinate and/or PEG-120 Methyl Glucose Dioleate to the container and mix.

7. Add Ethylene Glycol Stearate and/or Ethylene Glycol Distearate and/or Laureth-4 and/or C12-15 Alkyl Lactate and mix the ingredients.

8. Add EDTA and preservative to container and mix.

9. Add polyethylene and fragrance and mix.

10. Adjust the pH of the formulation to the desired pH using sodium hydroxide and/or citric acid.

11. Add hydrophobic cotton particles and/or hydrophilic cotton particles to the mixture.

Example 8: Study of sebum absorption using a cleansing composition

Before wetting the skin with running tap water, a baseline reading of sebum content was taken from the skin surface of nine subjects at selected skin test sites (three points - opposite ends and the middle of the forehead). Sebum content was measured using a sebometer. 0.5cc of gel cleanser (placebo) was applied to the skin and then the skin was massaged for ten seconds. Water was added to the skin and lathered on the skin for another twenty seconds. The cleanser and any excess residue were washed off the skin with water for thirty seconds, and then the blot was wiped dry with a Kimwipe.

These steps were repeated with hydrophobic and hydrophilic cotton particles as shown in Table 8, and excess water was allowed to air dry for approximately five minutes.

Sebum counts were measured continuously after washing by taking two points of the placebo and cotton prototypes at intervals, using a sebometer kit, 4 hours after washing and 6 hours after washing, respectively.

For accuracy, each sebum count should be performed on a fresh skin area (i.e., the same area should not be measured more than once). Once sebum is measured by the sebometer cartridge, the specific site will be destroyed, affecting the accuracy of the sebum measurement, as sebum is produced on the skin throughout the day.

The results of the sebum absorption measurements for Examples 9A and 9B are shown in Figure 7 (Example 9C was not tested in this example). As can be seen from the graph in Figure 7, sebum production was slowed for skin cleansed with the composition comprising hydrophobic and hydrophilic cotton particles compared to skin cleansed with a gel cleanser.

Table 8

Claims (16)

1. A wash-off skincare composition comprising: hydrophobic linear cellulose particles having an average length of 1 μm to 1000 μm, a particle aspect ratio of 1000 to 2, and a thickness of 1 μm to 500 μm; at least one cleanser selected from saponified fats and surfactants, wherein the cleanser is a surfactant and is present in an amount of 5% to 30% by weight of the composition; and a cosmetically acceptable carrier; the composition containing 50-90% a cosmetically acceptable aqueous solvent; the hydrophobic linear cellulose particles having an oil absorption capacity and oil retention capacity of 150% to 500% oil weight/particle weight. 2. The wash-off skincare composition according to claim 1, wherein the oil absorption capacity and oil retention capacity of the hydrophobic linear cellulose particles are 300% to 500% oil weight/particle weight. 3. The wash-off skincare composition according to claim 1, wherein the water contact angle of the hydrophobic linear cellulose particles is greater than 90 degrees. 4. The wash-off skin care composition according to claim 3, wherein the water contact angle is greater than 100 degrees. 5. The wash-off skin care composition according to claim 3, wherein the water contact angle is greater than 120 degrees. 6. The wash-off skincare composition according to claim 1, wherein the cellulose particles are derived from cotton. 7. The wash-off skin care composition according to claim 1, wherein the cellulose particles are coated with a hydrophobic agent selected from: metal soaps, organic waxes, long-chain fatty acids, long-chain fatty esters, water-insoluble polymers, and polymeric siloxanes. 8. The wash-off skin care composition according to claim 1, wherein the cellulose particles are coated with a hydrophobic agent selected from synthetic waxes. 9. The wash-off skincare composition according to claim 1, wherein the cellulose particles are coated with a hydrophobic agent selected from water-insoluble fluoropolymers. 10. The wash-off skincare composition according to claim 1, wherein the surfactant is selected from anionic surfactants, nonionic surfactants, and amphoteric surfactants. 11. The wash-off skin care composition according to claim 1, wherein the cellulose particles are cotton particles. 12. The wash-off skin care composition according to claim 1, wherein the cellulose particles are recycled cotton particles. 13. The wash-off skincare composition according to claim 1, wherein the cellulose particles are rayon particles. 14. The wash-off skincare composition according to claim 1, wherein the composition comprises 1% to 20% by weight of the cellulose particles. 15. The wash-off skincare composition according to claim 1, wherein the composition comprises 1% to 10% by weight of the cellulose particles. 16. The wash-off skincare composition of claim 1, wherein the composition comprises 1% to 6% by weight of the cellulose particles.