WO2001013871A1

WO2001013871A1 - Antiperspirant stick compositions providing improved deposition of the composition matrix onto skin

Info

Publication number: WO2001013871A1
Application number: PCT/US2000/022995
Authority: WO
Inventors: James David Landgrebe; Edward Dewey Smith, Iii
Original assignee: The Procter & Gamble Company
Priority date: 1999-08-23
Filing date: 2000-08-22
Publication date: 2001-03-01
Also published as: AU7064600A

Abstract

Disclosed are antiperspirant stick compositions that provide improved deposition of the composition matrix onto skin, wherein the antiperspirant stick compositions comprise antiperspirant particulate solids having a particle size distribution characterized by a ratio of a d90 value to mode particle size of from about 2.0 to about 10.0. Also disclosed are methods to improve the deposition of hard, waxy or other similar compositions to the skin and other substrates upon application, wherein the method comprises incorporating into the composition a particulate solid having a defined particle size distribution.

Description

ANTIPERSPIRANT STICK COMPOSITIONS PROVIDING IMPROVED DEPOSITION OF THE COMPOSITION MATRIX ONTO SKIN

FIELD OF THE INVENTION The present invention relates to antiperspirant stick compositions that provide improved deposition of the composition matrix onto skin, wherein the composition contains antiperspirant particulate solids having a particle size distribution characteπzed by specific mode particle size and d90 values The present invention is also directed to methods of improving the deposition of other hard, waxy compositions onto skin or other substrate through the use of particulate solids having defined mode particle size and d90 values

BACKGROUND OF THE INVENTION

Hard, waxy compositions are used frequently in consumer products They include products ranging from crayons to solid antiperspirant stick products Recent applications of these compositions include their use on nonwoven or woven substrates, in products such as cleansing cloths and diapers, as a means of depositing ingredients to skin from these products

The use of waxy compositions in these products generally has required a benefits trade-off Waxy compositions generally need to be relatively soft to rub off and deposit on the skin or other applied surface Soft waxes, however, tend to be messy and are difficult to package Soft waxes are also more unstable as far as their ability to suspend active ingredients or pigments For these reasons, consumer products manufacturers are forced to use harder, waxy structures in their products, with the resulting products depositing less on the skin than may be desired

It has now been found that the deposition of hard, waxy structure compositions may be increased by the incorporation of a particulate solid having a particle size distribution with specific characteristics, into the composition Without being limited by theory, it is believed that these specific particulate solids uniquely interfere with the crystal structure of the hard, waxy solid which results in improved shearing of the solid upon application without significantly reducing the hardness of the solid, as measured by penetration testing

It has also been found that the defined particle size characteristics are especially useful when applied to particulate antiperspirant solids in solid antiperspirant stick compositions

SUMMARY OF THE INVENTION

The present invention is directed to antiperspirant stick compositions comprising particulate antiperspirant active, wherein the particulate antiperspirant active has a particle size distribution characterized by a ratio of a d90 value to mode particle size of from about 2.0 to about 10.0. The present invention is also directed to methods of improving the deposition of a antiperspirant stick compositions and other hard, waxy products to the skin and other applied surface by incorporating into the compositions a particulate solid having a particle size distribution characterized by a mode particle size of from about 20μm to about lOOμm. It has been found that the deposition of antiperspirant sticks and other similar hard, waxy compositions intended for application to the skin or other applied surface, can be improved by incorporating into such compositions particulate solids having a particle size distribution as characterized herein. These compositions deposit more efficiently on the desired applied surface without additional force being applied and without requiring any significant reduction in product hardness to achieve the improved deposition.

DETAILED DESCRIPTION OF THE INVENTION

The term "deposition" as used herein refers to the amount of an antiperspirant stick composition or other solid composition (e.g., hard, waxy compositions) transferred to the skin during application from a container or substrate. In this context, the terms "improved deposition" and "deposition efficiency" as used herein refer to the increased amount of product that can be applied to the desired surface with any given application but without any additional force being applied during that application and without any significant reduction in the compositions product hardness . The term "particulate solid" as used herein means any solid material in the antiperspirant or other solid composition described herein which is in the form of discrete particles, including solid antiperspirant active in particulate form, and which have the particle size and distribution characteristics defined herein. In this context, the discrete particles or particulate solids typically have particle diameters ranging from about lμm to about lOOOμm, although it is understood that these particulate solids can also include small fractions of smaller or larger diameter particles as well.

The term "d90 value" as used herein is the measured diameter of a particle within a particulate solids distribution such that 90% of the particles within that distribution have an average diameter that falls below the d90 value. The term "mode particle size" as used herein means the particle diameter of the particulate solids described herein at which point there is the highest percentage of such particles having that diameter.

The term "hard, waxy composition" as used herein refers generally to compositions that are solid under ambient conditions (e.g., one atmosphere of pressure, 50% relative humidity, 25 °C) and are intended for topical application to the skin or other applied surface. This particular term carries with it no other meaning or limitation for purposes of defining the methods and compositions of the present invention, unless otherwise specified for preferred embodiments thereof.

The term "volatile" as used herein, unless otherwise specified, refers to those materials which have a measurable vapor pressure at 25°C. Such vapor pressures will typically range from about 0.01 mmHg to about 6 mmHg, more typically from about 0.02 mmHg to about 1.5 mmHg, and have an average boiling point at one (1) atmosphere of pressure (atm) of less than about 250°C, more typically less than about 235°C at one (1) atm. Conversely, the term "non volatile" refers to those materials which are not "volatile" as defined herein, unless otherwise specified. The antiperspirant compositions and methods of the present invention can comprise, consist of, or consist essentially of the essential elements and limitations of the invention described herein, as well as any additional or optional ingredients, components, or limitations described herein or otherwise suitable for use in such compositions and methods. These compositions and methods can likewise be substantially free of any or all such additional or optional ingredients, components, or limitations.

All numerical ranges described herein shall hereby expressly include each and every numerical value falling with that numerical range as if each and every numerical value were expressly written therein; and all percentages, parts and ratios are by weight of the total composition, unless otherwise specified. All such weights as they pertain to listed ingredients are based on the specific ingredient level and, therefore, do not include solvents, carriers, byproducts, filler or other minor ingredients that may be included in commercially available materials, unless otherwise specified.

The essential elements of the compositions and methods of the present invention, and non-limiting examples of some optional elements, are described in greater detail hereinafter.

Particulate Solids

The methods and compositions of the present invention are directed to or comprise the incorporation of particulate solids into a hard, waxy or other similar composition to improve the deposition efficiency of the composition when applied to the skin or other applied surface. The particulate solids may comprise any solid material which is insoluble in the hard, waxy composition.

The particulate solid for use in the compositions and methods of the present invention are used to increase or otherwise improve the deposition efficiency of such compositions when applied to the skin or other applied surface. These particulate solids have a particle size distribution such that the mode particle size is greater than about 20μm, preferably greater than about 25μm, more preferably greater than about 30μm and less than about lOOμm, preferably less than about 75μm, and more preferably less than about 50μm. It is understood, however, that other particulate solids may be added to the composition which have a mode particle size of less than 20 μm, so long as the other particulate solids are also added to the composition which have the above-described mode particle size values

The concentration of particulate solids for use in the antiperspirant stick compositions and methods is described hereinbefore For other hard, waxy or other similar compositions to which the methods of the present invention apply, particulate solid concentrations preferably range from about 0 25% to about 10%, more preferably from about 0 5% to about 5%, and even more preferably from about 1% to about 4%, by weight of the composition

The particulate solids can include any organic or inorganic, natural or synthetic, active or inert, solid material having the requisite solubility and particle size characteristics as defined herein Non-limiting examples of particulate solids suitable for use herein include inert polymeric or plastic particulates, skin active materials such as solid antiperspirant active as described hereinbefore, inorganic oxide particles such as titanium and zinc oxides, and other cosmetic particles such as polysiloxane particles (e g , dimethicone, alkyl dimethicones, phenyl methicones, crosshnked dimethicone, cross-linked alkyl dimethicone, etc ) Other suitable particulate solids include boron nitride from Wacker Silicone, Munich, Germany, starch particles such as aluminum starch octenylsuccmate from National Starch and Chemical Co , Bπdgewater, New Jersey, USA, mica, talc, and combinations thereof

The method of the present invention is directed to the formulation and application of hard, waxy compositions comprising separate particulate solids having a mode particle size of less than about 12μm It has been found that particulate solids having a mode particle size of less than 12μm do not disrupt the crystal structure within the hard waxy or other composition enough to increase deposition of that composition to the skin or other applied surface Therefore, the method and corresponding compositions of the present invention are directed to the application and incorporation of particulate solids into such compositions such that the incorporated particulate solids have a mode particle size of from about 20μm to about lOOμm so that they will now help to increase the deposition of the composition onto the skm or other applied surface Such compositions may or may not then further comprise the particulate solids having a mode particle size of less than 12 μm

It has been found that specifically for solid antiperspirant sticks having solid actives with a particle size distribution having a mode particle size less than about 12μm that it is preferred that the particulate solid used is a particulate solid which also compnses antiperspirant particulate solids having a mode particle size of from about 20μm to about lOOμm Specifically preferred is a combination of solid particulate antiperspirant active such that the particle size distribution of the total solid particles or total solid antiperspirant particles in the composition has a ratio of the d90 value to mode particle size of from about 2 0 to about 10 0, preferably from about 2 0 to about 4 5, more preferably from about 2 5 to about 4 0 To achieve this preferred distribution, the ratio of the amount of the solid active having a mode particle size of less than about 12μm and the amount of particulate active or other solid having a mode particle size greater than about 20μm is greater than about 5 1 , preferably greater than about 6 1 and less than about 75 1 , preferably less than about 50 1 , more preferably less than about 30 1 It is also possible to eliminate the particulate solids having a mode particle size of less than 12 μm so long as the other particulate solids remain in the composition

Particulate solids for use in the compositions and methods of the present invention, including antiperspirant stick compositions, will not typically contain particle solids comprising discrete particles all having exactly the same diameter Processes for making solid particulates, such as crystallization, spray drying or grinding, normally result in particles having sizes which result in a particle size distribution A particle size distribution is a statistical evaluation of the percent of particles having a given size, expressed as a particle diameter or more commonly volume, under the assumption of spherical particles, measured over the full range of sizes seen in the distribution The particle size of particulate solids as defined herein are measured with a Coulter Multisizer 1 1 manufactured by Coulter Corporation, Haleah, Florida Particle size or other measurement distribution with respect to such particulate solid measurements can be characterized in terms of a measured value mean or average, a median or mid-point, and/or a mode The mode particle size and d90 values as described herein are determined in accordance with the Coulter measurements and the above- described assumptions and process

Solid Antiperspirant Sticks

The compositions of the present invention include antiperspirant stick compositions comprising solid particulates as defined herein, including solid antiperspirant particulates having the defined particulate solid characteristics defined herein The solid antiperspirant particulates having the defined characteristics can be used in any solid stick formulation that is known or otherwise effective for use in controlling or inhibiting underarm perspiration and/or underarm odor associated with such perspiration. These compositions will also typically comprise a suitable suspending or thickening agent and a suitable liquid carrier.

The antiperspirant stick compositions of the present invention are preferably anhydrous and are therefore preferably substantially free of added or free water. From a formulation standpoint, this means that the anhydrous antiperspirant embodiments of the present invention preferably contain less than about 5%, more preferably less than about 3%, even more preferably less than about 1%, most preferably zero percent, by weight of free or added water, other than the water of hydration typically associated with the particulate antiperspirant active prior to formulation. The antiperspirant stick compositions of the present invention have a product hardness that is preferably at least about 600 gram-force, most typically from about 600 gram-force to about 5,000 gram-force, more preferably from about 750 gram-force to about 2,000 gram- force, even more preferably from about 800 gram- force to about 1,400 gram-force. The term "product hardness" or "hardness" as used herein is a reflection of how much force is required to move a penetration cone a specified distance and at a controlled rate into an antiperspirant stick composition under the following test conditions. Higher values represent harder product, and lower values represent softer product. These values are measured at 27°C, 15% relative humidity, using a TA-XT2 Texture Analyzer, available from Texture Technology Corp., Scarsdale, New York, U.S.A. The product hardness value as used herein represents the peak force required to move a standard 45° angle penetration cone through the composition for a distance of 10mm at a rate of 2mm/second. The standard cone is available from Texture Technology Corp., as part number TA-15, and has a total cone length of about 24.7 mm, angled cone length of about 18.3 mm, a maximum diameter of the angled surface of the cone of about 15.5 mm. The cone is a smooth, stainless steel construction and weighs about 17.8 grams.

The antiperspirant stick compositions of the present invention comprise antiperspirant active in solid particulate form, most or all of which has the particle size characteristics of the solid particulates defined herein. The particle size characterization of the solid particulate active in these antiperspirant stick compositions is important for the desired product performance. Preferably at least about 25%, more preferably at least about 50%, even more preferably 100%, of the antiperspirant active in the compositions have the particle size characteristics as defined herein.

The concentration of solid antiperspirant active in the composition should be sufficient to provide the desired perspiration wetness and/or odor control, but will typically range from about 0.1% to about 50%, more preferably from about 5% to about 35%, even more typically from about 10% to about 26%, by weight of the composition. These weight percentages are calculated on an anhydrous metal salt basis exclusive of water and any complexing agents such as glycme, glycine salts, or other complexing agents

Antiperspirant active suitable for use in the compositions of the present invention include any compound, composition or other material having antiperspirant activity, preferably astringent metallic salts, especially the inorganic and organic salts of aluminum, zirconium and zinc, as well as mixtures thereof Particularly preferred are the aluminum and zirconium salts, such as aluminum hahdes, aluminum chlorohydrate, aluminum hydroxyhalides, zirconyl oxyha des, zirconyl hydroxyhalides, and mixtures thereof

Preferred aluminum salts for use in the antiperspirant stick compositions include those which conform to the formula

Al₂(OH)_a Cl _b x H₂0 wherein a is from about 2 to about 5, the sum of a and b is about 6, x is from about 1 to about 6, and wherein a, b, and x may have non-integer values Particularly preferred are the aluminum chlorohydroxides referred to as "5/6 basic chlorohydroxide", wherein a = 5, and "2/3 basic chlorohydroxide", wherein a = 4 Processes for preparing aluminum salts are disclosed in U S Patent 3,887,692, Gilman, issued June 3, 1975, U S Patent 3,904,741 , Jones et al , issued September 9, 1975, U S Patent 4,359,456, Gosling et al , issued November 16, 1982, and British Patent Specification 2,048,229, Fitzgerald et al , published December 10, 1980, all of which are incorporated herein by reference Mixtures of aluminum salts are described in Bπtish Patent Specification 1 ,347,950, Shin et al , published February 27, 1974, which description is also incorporated herein by reference

Preferred zirconium salts for use in the antiperspirant stick compositions include those which conform to the formula

ZrO(OH)₂._aCl_a x H₂0 wherein a is from about 1 1 to about 2 0, x is from about 1 to about 8, and wherein a and x may both have non-integer values These zirconium salts are described in Belgian Patent 825,146, Schmitz, issued August 4, 1975, which description is incorporated herein by reference Particularly preferred zirconium salts are those complexes which additionally contain aluminum and glycine, commonly known as ZAG complexes These ZAG complexes contain aluminum chlorohydroxide and zirconyl hydroxy chloride conforming to the above described formulas Such ZAG complexes are described in U S Patent 3,679,068, Luedders et al , issued February 12, 1974, Great Britain Patent Application 2,144,992, Callaghan et al , published March 20, 1985, and U S Patent 4,120,948, Shelton, issued October 17, 1978, all of which are incorporated herein by reference The antiperspirant stick compositions of the present invention will typically compπse a carrier liquid suitable for topical application to the skin Any carrier liquid can be used m the composition so long as it is compatible with the other ingredients or does not otherwise unduly affect product performance. The carrier liquids can be organic or silicone-containing, volatile or non volatile, aqueous or anhydrous (preferably anhydrous). The concentration of such carrier liquids in the antiperspirant compositions can range from about 1% to about 95%, preferably from about 10% to about 90%, even more preferably from about 30% to about 85%, most preferably from about 30% to about 75%, by weight of the composition.

The carrier liquid within the antiperspirant composition preferably comprises a volatile carrier liquid, e.g., volatile silicone, volatile isoparafin or other organic liquid, preferably a volatile silicone liquid such as volatile cyclomethicone, e.g., cyclopentasiloxane, cyclohexasiloxane, cyclopentasiloxane, combinations thereof. The volatile carrier liquid can represent from zero to 100%, preferably from about 20% to 100%), more preferably from about 20%) to about 90%, by weight of the carrier liquid. Nonlimiting examples of suitable volatile silicone materials are described in Todd et al., "Volatile Silicone Fluids for Cosmetics", Cosmetics and Toiletries, 91 :27-32 (1976), which descriptions are incorporated herein by reference.

Other suitable carrier liquids for use in the antiperspirant stick composition are described in U.S. Patent 5,750,096 (Guskey); U.S. Patent 5,976,514 (Guskey); U.S. Patent

5,733,534 (Sawin et al); U.S. Patent 5,718,890 (Putman et al.); U.S. Patent 5,429,816

(Hofrichter et al.); U.S. Patent 5,605,681 (Trandai et al.); and U.S. Patent 5,585,092 (Trandai et al.), which descriptions are incorporated herein by reference.

The antiperspirant stick compositions of the present invention will typically also comprise a nonvolatile silicone liquid such as a polydimethylsiloxane fluid at concentrations ranging from about 1% to about 35%, preferably from about 2% to about 20%, by weight of the composition. When used in the composition, these non-volatile silicone liquids are preferably used in combination with volatile silicone liquid (e.g., cyclopentasiloxane, cyclohexasiloxane, cyclotetrasiloxane) as described in U.S. Patent 5,156,834 (Beckmeyer et al.), which patent is incorporated herein by reference.

The antiperspirant stick compositions of the present invention, in order to obtain the desired product hardness for a solid stick formulation, will typically also comprise a suspending or thickening agent to help provide the composition with the desired viscosity, rheology, texture or product hardness, or to otherwise help suspend any dispersed solids or liquids within the composition. The terms "suspending agent" and "thickening agent" are used interchangeably herein and include any material known or otherwise effective in providing suspending, gelling, viscosifying, solidifying or thickening properties to the composition or which otherwise provide structure to the final product form. These suspending or thickening agents include gelling agents, and polymeric or nonpolymeric or inorganic thickening or viscosifying agents Such materials will most typically be solids under ambient conditions and include organic solids, silicone solids, crystalline or other gellants, inorganic particulates such as clays or silicas, polymeric thickeners (e g , silicone elastomers, silicone copolymers) or combinations thereof The concentration and type of suspending or thickening agent selected for use in the antiperspirant stick composition will vary depending upon the desired product form, viscosity, hardness and/or other product characteristics For most suspending or thickening agents suitable for use herein, the concentration will most typically range from about 0 1% to about 50%, more typically from about 1% to about 35%, preferably from about 1% to about 25%, most preferably from about 5% to about 25%, by weight of the composition

Suitable suspending or thickening agents in the antiperspirant stick compositions include, but are not limited to, fatty acid gellants, salts of fatty acids, hydroxy acid gellants, esters and amides of fatty acid or hydroxy fatty acid gellants, cholesterohc materials, dibenzy dene alditols, lanolinohc materials, fatty alcohols, tπglycendes, sucrose esters, inorganic materials such as clays or silicas, and other suitable gellants

Other suitable suspending or thickening agents include gellants such as fatty alcohols having from about 8 to about 40 carbon atoms, preferably from 8 to about 30 carbon atoms, more preferably from about 12 to about 18 carbon atoms These gellants are wax-like mateπals which are most typically used at concentrations ranging from about 1% to about 30%, preferably from about 5% to about 20%, most preferably from about 10% to about 20%, by weight of the antiperspirant stick compositions

Other suitable suspending or thickening agents for use in the antiperspirant stick compositions include waxes or wax-like materials having a melt point of above 65°C, more typically from about 65°C to about 130°C, examples of which include, but are not limited to, waxes such as beeswax, camauba, baysberry, candelilla, montan, ozokerite, ceresin, hydrogenated castor oil (castor wax), synthetic waxes, microcrystalline waxes Castor wax is preferred within this group Other high melting point waxes are described in U S Patent 4,049,792 (Elsnau), which description is incorporated herein by reference

Other suitable suspending or thickening agents for use in the antiperspirant stick compositions include fatty acid gellants such as fatty acid and hydroxy acids such as alpha or beta hydroxy fatty acids, having from about 10 to about 40 carbon atoms, and esters and amides of such gelling agents Nonlimiting examples such gellants include 12-hydroxysteaπc acid, 12-hydroxylauπc acid, 16-hydroxyhexadecanoιc acid, behenic acid, eurcic acid, steaπc acid, caprylic acid, lauπc acid, lsosteaπc acid, and combinations thereof Preferred are 12-hydroxysteaπc acid, esters of 12-hydroxysteaπc acid, amides of 12-hydroxysteaπc acid and combinations thereof, and all other gelling agents which correspond to the following formula

wherein Ri is OR₂ NR₂Rβ , or a silicone containing moiety, and R₂ and R3 are hydrogen, or an alkyl, aryl, or arylalkyl radical which is branched linear or cyclic and has from about 1 to about 22 carbon atoms, preferably, from about 1 to about 18 carbon atoms R₂ and R3 may be either the same or different, however, at least one is preferably a hydrogen atom Preferred among these gellants are those selected from the group consisting of 12-hydroxysteaπc acid, 12-hydroxysteaπc acid methyl ester, 12-hydroxysteaπc acid ethyl ester, 12-hydroxysteaπc acid stearyl ester, 12-hydroxysteaπc acid benzyl ester, 12-hydroxysteaπc acid amide, isopropyl amide of 12-hydroxysteaπc acid, butyl amide of 12-hydroxysteaπc acid, benzyl amide of 12-hydroxysteaπc acid, phenyl amide of 12-hydroxysteaπc acid, t-butyl amide of 12- hydroxysteaπc acid, cyclohexyl amide of 12-hydroxysteaπc acid, 1-adamantyl amide of 12- hydroxysteaπc acid, 2-adamantyl amide of 12-hydroxysteaπc acid, dnsopropyl amide of 12- hydroxysteaπc acid, and mixtures thereof, even more preferably, 12-hydroxysteaπc acid, isopropyl amide of 12-hydroxysteaπc acid, and combinations thereof Most preferred is 12- hydroxysteaπc acid

Suitable amide gellants include disubstituted or branched monoamide gellants, monosubstituted or branched diamide gellants, tπamide gellants, and combinations thereof, including n-acyl amino acid derivatives such as n-acyl amino acid amides, n-acyl amino acid esters prepared from glutamic acid, lysme, glutamine, aspartic acid, and combinations thereof Other suitable amide gelling agents are described in U S Patent 5,429,816 (Hofrichter et al ) and U S Patent 5,840,287 (Guskey et al ), which descriptions are incorporated herein by reference Concentrations of all such gellants preferably range from about 0 1% to about 25%, more preferably of from about 1% to about 15%, more preferably from about 1% to about 10%, by weight of the antiperspirant and deodorant compositions

Other suitable suspending or thickening agents for use in the antiperspirant stick compositions include triglyceride gellant systems which comprise glyceryl tπbehenate or other solid tπglyceπdes Nonlimiting examples of some commercially available solid triglyceride gellants for use in the compositions include tπsteaπn, tπbehenin, C18-36 tnglyceπdes, hydrogenated vegetable oil, tπhydroxysteπn (Thixcm® R, available from Rheox, Inc ), rape seed oil, castor wax, fish oils, tπpalmitin, and linear Syncrowaxes® such as Syncrowax® HRC and Syncrowax® HGL-C (Syncrowax® available from Croda, Inc ) Other suitable suspending or thickening agents for use in the antiperspirant stick compositions include particulate suspending or thickening agents such as clays and colloidal pyrogenic silica pigments Other known or otherwise effective particulate suspending or thickening agents can likewise be used in the antiperspirant composition. Concentrations of optional particulate thickening agents preferably range from about 0 1% to about 15%, more preferably from about 1% to about 15%, even more preferably from about 1% to about 8%, by weight of the composition Colloidal pyrogenic silica pigments are preferred, a common example of which includes Cab-O-Sil ®, a submicron particulated pyrogenic silica

Suitable clay suspending or thickening agents include montmoπllonite clays, examples of which include bentonites, hectorites, and colloidal magnesium aluminum silicates These and other suitable clay suspending agents are preferably hydrophobically treated, and when so treated will generally be used in combination with a clay activator Nonlimiting examples of suitable clay activators include propylene carbonate, ethanol, and combinations thereof The amount of clay activator will typically range from about 25% to about 75% by weight of the clay, more typically from about 40% to about 60% by weight of the clay

The antiperspirant stick compositions of the present invention may further comprise one or more other optional materials that are known for use in antiperspirant compositions or other personal care products, or which are otherwise suitable for topical application to human skin Nonlimiting examples of such other optional materials include dyes or colorants, emulsifiers, perfumes, distributing agents, pharmaceutical or other topical active, preservatives, surfactants, processing aides such as viscosity modifiers, wash-off aids, and so forth Examples of such optional materials are described in U.S Patent 4,049,792 (Elsnau), U S Patent 5,019,375 (Tanner et al ), and U S Patent 5,429,816 (Hofrichter et al ), which descriptions are incorporated herein by reference. The antiperspirant compositions of the present invention preferably further comprise solid antiperspirant active having a mode particle size of less than about 20μm, preferably less than about 12μm, all at the active concentrations described herein, and preferably a density greater than about 0 7 g/cn

The term hard, waxy material or compositions to which all of the methods and compositions of the present invention are directed, including the antiperspirant and other compositions, will most typically comprise one or more of the suspending or thickening agents as described heremabove

Other Compositions The methods of the present invention can also be applied to hard, waxy compositions for use in or otherwise associated with diapers, feminine protection products, cleansing wipes, non-cleansing wipes, moisturing wipes, cleansing products and other similar consumer products. These consumer products can comprise materials that contain waxes and fatty alcohols, e.g., stearyl alcohol, to help deliver skin protectants and moisturizers such as petrolatum or zinc oxide, other any other desired material, to the skin. The hard, waxy compositions can, for example, be coated onto or otherwise placed in contact with a substrate (e.g., diaper substrate) within the consumer product item for application to the desired area of the skin. The solid particulates as defined herein help to improve the transfer efficiency, i.e., increase the amount of coating delivered from a substrate onto skin divided by or relative to the total amount of coating on the substrate.

Application Implement

The compositions of the present invention may be combined with an appropriate application implement to provide an article of manufacture consumers may use to conveniently apply the composition to the skin and other substrates. The implement may be anything which may deliver the composition to the skin or other substrates such as a container filled with the composition or a substrate coated or impregnated with the composition.

Container

The article of manufacture of the present invention may comprise any container, bottle, wrap or package which may be filled with the composition.

Substrate

The articles of manufacture of the present invention may comprise a water insoluble substrate as an application device to apply the hard, waxy composition to the skin or other substrates. By "water insoluble" is meant that the substrate does not dissolve in or readily break apart upon immersion in water.

A wide variety of materials can be used as the substrate. The following nonlimiting characteristics are desirable: (i) sufficient wet strength for use, (ii) sufficient abrasivity, (iii) sufficient loft and porosity, (iv) sufficient thickness, and (v) appropriate size. Nonlimiting examples of suitable insoluble substrates which meet the above criteria include nonwoven substrates, woven substrates, hydro- or fluid-entangled substrates, air entangled substrates, natural sponges, synthetic sponges, polymeric netted meshes, and the like. Preferred embodiments employ nonwoven substrates since they are economical and readily available in a variety of materials. By nonwoven is meant that the layer is comprised of fibers which are not woven into a fabric but rather are formed into a sheet, mat, or pad layer. The fibers can either be random (i.e., randomly aligned) or they can be carded (i.e. combed to be oriented in primarily one direction). Furthermore, the nonwoven substrate can be composed of a combination of layers of random and carded fibers.

Nonwoven substrates may be comprised of a variety of materials both natural and synthetic. By natural is meant that the materials are derived from plants, animals, insects or byproducts of plants, animals, and insects. By synthetic is meant that the materials are obtained primarily from various man-made materials or from natural materials which have been further altered The conventional base starting material is usually a fibrous web comprising any of the common synthetic or natural textile-length fibers, or mixtures thereof.

Nonlimiting examples of natural materials useful in the present invention are silk fibers, keratin fibers and cellulosic fibers Nonlimiting examples of keratin fibers include those selected from the group consisting of wool fibers, camel hair fibers, and the like. Nonlimiting examples of cellulosic fibers include those selected from the group consisting of wood pulp fibers, cotton fibers, hemp fibers, jute fibers, flax fibers, and mixtures thereof.

Nonlimiting examples of synthetic materials useful in the present invention include those selected from the group consisting of acetate fibers, acrylic fibers, cellulose ester fibers, modacryhc fibers, polyamide fibers, polyester fibers, polyolefin fibers, polyvinyl alcohol fibers, rayon fibers, polyurethane foam, and mixtures thereof Examples of some of these synthetic materials include acrylics such as acπlan, creslan, and the acrylonitπle-based fiber, orlon; cellulose ester fibers such as cellulose acetate, arnel, and acele; polyamides such as nylons (e.g., nylon 6, nylon 66, nylon 610, and the like); polyesters such as fortrel, kodel, and the polyethylene terephthalate fiber, dacron; polyolefins such as polypropylene, polyethylene; polyvinyl acetate fibers, polyurethane foams and mixtures thereof. These and other suitable fibers and the nonwoven materials prepared therefrom are generally described in Riedel, "Nonwoven Bonding Methods and Materials," Nonwoven World (1987); The Encyclopedia Americana, vol 1 1, pp 147-153, and vol. 26, pp. 566-581 (1984); U.S. Patent No 4,891,227, to Thaman et al., issued January 2, 1990; and U S Patent No. 4,891,228 which are all incorporated by reference herein in their entirety.

Nonwoven substrates made from natural materials consist of webs or sheets most commonly formed on a fine wire screen from a liquid suspension of the fibers. See CA. Hampel et al., The Encyclopedia of Chemistrv. third edition, 1973, pp. 793-795 (1973); The Encyclopedia Americana, vol 21, pp. 376-383 (1984); and G.A Smook, Handbook of Pulp and Paper Technologies. Technical Association for the Pulp and Paper Industry (1986); which are incorporated by reference herein m their entirety.

Substrates made from natural materials useful in the present invention can be obtained from a wide variety of commercial sources. Nonlimiting examples of suitable commercially available paper layers useful herein include Aιrtex* an embossed airlaid cellulosic layer having a base weight of about 71 gsy, available from James River, Green Bay, WI; and Walkisoft , an embossed airlaid cellulosic having a base weight of about 75 gsy, available from Walkisoft U.S.A., Mount Holly, NC.

Methods of making nonwoven substrates are well known in the art. Generally, these nonwoven substrates can be made by air-laying, water-laying, eltblowing, coforming, spunbonding, or carding processes in which the fibers or filaments are first cut to desired lengths from long strands, passed into a water or air stream, and then deposited onto a screen through which the fiber-laden air or water is passed. The resulting layer, regardless of its method of production or composition, is then subjected to at least one of several types of bonding operations to anchor the individual fibers together to form a self-sustaining web. In the present invention the nonwoven layer can be prepared by a variety of processes including hydroentanglement, thermally bonding or thermo-bonding, and combinations of these processes. Moreover, the substrates of the present invention can consist of a single layer or multiple layers. In addition, a multilayered substrate can include films and other nonfibrous materials.

Nonwoven substrates made from synthetic materials useful in the present invention can also be obtained from a wide variety of commercial sources. Nonlimiting examples of suitable nonwoven layer materials useful herein include HEF 40-047, an apertured hydroentangled material containing about 50% rayon and 50%> polyester, and having a basis weight of about 43 grams per square yard (gsy), available from Veratec, Inc., Walpole, MA; HEF 140-102, an apertured hydroentangled material containing about 50% rayon and 50% polyester, and having a basis weight of about 56 gsy, available from Veratec, Inc., Walpole, MA; NovonetR 149-616, a thermo-bonded grid patterned material containing about 100% polypropylene, and having a basis weight of about 50 gsy, available from Veratec, Inc., Walpole, MA; Novonet^ 149-801, a thermo-bonded grid patterned material containing about 69% rayon, about 25% polypropylene, and about 6% cotton, and having a basis weight of about 75 gsy, available from Veratec, Inc. Walpole, MA; Novonet^ 149-191, a thermo-bonded grid patterned material containing about 69% rayon, about 25% polypropylene, and about 6% cotton, and having a basis weight of about 100 gsy, available from Veratec, Inc. Walpole, MA; HEF Nubtex 149-801, a nubbed, apertured hydroentangled material, containing about 100%) polyester, and having a basis weight of about 70 gsy, available from Veratec, Inc. Walpole, MA; Keybak^ 951V, a dry formed apertured material, containing about 75%> rayon, about 25% acrylic fibers, and having a basis weight of about 43 gsy, available from Chicopee, New Brunswick, NJ; Keybak^ 1368, an apertured material, containing about 75%) rayon, about 25% polyester, and having a basis weight of about 39 gsy, available from Chicopee, New Brunswick, NJ; Duralace^ 1236, an apertured, hydroentangled material, containing about 100%) rayon, and having a basis weight from about 40 gsy to about 115 gsy, available from Chicopee, New Brunswick, NJ, Duralace^ 5904, an apertured, hydroentangled material, containing about 100% polyester, and having a basis weight from about 40 gsy to about 1 15 gsy, available from Chicopee, New Brunswick, NJ, Sontaro 8868, a hydroentangled material, containing about 50% cellulose and about 50% polyester, and having a basis weight of about 60 gsy, available from Dupont Chemical Corp

Alternatively, the water insoluble substrate can be a polymeric mesh sponge as described in European Patent No EP 702550 Al published March 27, 1996, incorporated by reference herein in its entirety The poiymeπc sponge comprises a plurality of plies of an extruded tubular netting mesh prepared from a strong flexible polymer, such as addition polymers of olefin monomers and polyamides of polycarboxy c acids Although these polymeric sponges are designed to be used in conjunction with a liquid cleanser, these types of sponges can be used as the water insoluble substrate in the present invention

The substrate can be made into a wide variety of shapes and forms including flat pads, thick pads, thin sheets, ball-shaped implements, irregularly shaped implements, and having sizes ranging from a surface area of about a square inch to about hundreds of square inches The exact size will depend upon the desired use and product characteristics Especially convenient are square, circular, rectangular, or oval pads having a surface area of from about 1 ιn^ to about 144 m^, preferably from about 10 ιn^ to about 120 in^, and more preferably from about 30 ιn^ to about 80 ιn and a thickness of from about 1 mil to about 500 mil, preferably from about 5 mil to about 250 mil, and more preferably from about 10 mil to about 100 mil

The water insoluble substrates of the present invention can comprise two or more layers, each having different textures and abrasiveness The differing textures can result from the use of different combinations of materials or from the use of different manufacturing processes or a combination thereof A dual textured substrate can be made to provide the advantage of having a more abrasive side for exfoliation and a softer, absorbent side for gentle cleansing In addition, separate layers of the substrate can be manufactured to have different colors, thereby helping the user to further distinguish the surfaces

Preferable articles of the present invention comprise a water insoluble substrate which comprises a non-scouring, lofty, low-density batting layer and a non-lofty, fluid-permeable nonwoven layer The batting layer of the present invention is lofty, non-scouring, and is of low-density As used herein, "lofty" means that the layer has density of from about 0 00005 g/cm³ to about 0 1 g/cm³, preferably from about 0 001 g/cm³ to about 0 09 g/cm³ and a thickness of from about 0 04 inches to about 2 inches at 5 gms/in² Nonwovens made from synthetic materials useful the present invention can be obtained from a wide variety of commercial sources Nonlimiting examples of suitable nonwoven layer materials useful herein include HEF 40-047, an apertured hydroentangled material containing about 50% rayon and 50%> polyester, and having a basis weight of about 61 grams per square meter (gsm), available from Veratec, Inc., Walpole, MA; HEF 140-102, an apertured hydroentangled material containing about 50% rayon and 50% polyester, and having a basis weight of about 67 gsm, available from Veratec, Inc., Walpole, MA; Novonet® 149-616, a thermo-bonded grid patterned material containing about 100%o polypropylene, and having a basis weight of about 60 gsm available from Veratec, Inc., Walpole, MA; Novonet® 149-801, a thermo-bonded grid patterned material containing about 69%> rayon, about 25% polypropylene, and about 6% cotton, and having a basis weight of about 90 gsm, available from Veratec, Inc. Walpole, MA; Novonet® 149-191, a thermo-bonded grid patterned material containing about 69% rayon, about 25% polypropylene, and about 6% cotton, and having a basis weight of about 120 gsm, available from Veratec, Inc. Walpole, MA; HEF Nubtex® 149- 801 , a nubbed, apertured hydroentangled material, containing about 100% polyester, and having a basis weight of about 84 gsm, available from Veratec, Inc. Walpole, MA; Keybak® 951V, a dry formed apertured material, containing about 75%> rayon, about 25% acrylic fibers, and having a basis weight of about 51 gsm, available from Chicopee, New Brunswick, NJ; Keybak® 1368, an apertured material, containing about 75% rayon, about 25%_> polyester, and having a basis weight of about 47 gsm, available from Chicopee, New Brunswick, NJ; Duralace® 1236, an apertured, hydroentangled material, containing about 100% rayon, and having a basis weight from about 48 gsm to about 138 gsm, available from Chicopee, New Brunswick, NJ; Duralace® 5904, an apertured, hydroentangled material, containing about 100% polyester, and having a basis weight from about 48 gsm to about 138 gsm, available from Chicopee, New Brunswick, NJ; Chicopee® 5763, a carded hydroapertured material (8x6 apertures per inch, 3X2 apertures per cm), containing about 70% rayon, about 30% polyester, and a optionally a latex binder (Acrylate or EVA based) of up to about 5% w/w, and having a basis weight from about 60 gsm to about 90 gsm, available form Chicopee, New Brunswick, NJ; Chicopee® 9900 series (e.g., Chicopee 9931, 62 gsm , 50/50 rayon/polyester, and Chicopee 9950 50 gsm , 50/50 rayon/polyester), a carded, hydroentangled material, containing a fiber composition of from 50%> rayon/50% polyester to 0%> rayon/100%) polyester or 100% rayon 0% polyester, and having a basis weight of from about 36 gsm to about 84 gsm, available form Chicopee, New Brunswick, NJ; Sontara 8868, a hydroentangled material, containing about 50%> cellulose and about 50%> polyester, and having a basis weight of about 72 gsm, available from Dupont Chemical Corp. Preferred non-woven substrate materials have a basis weight of about from 24 gsm to about 96 gsm, more preferably from about 36 gsm to about 84 gsm , and most preferably from about 42 gsm to about 78 gsm. The nonwoven layer may also comprise formed films and composite materials, i.e., multiply materials containing formed films.

In another embodiment, the nonwoven layer comprises a plastic formed film which is both microapertured and macroapertured. In such embodiments, the nonwoven layer is well- suited to contact the area to be cleansed given the cloth-like feel of such microapertured films. Preferably, in such an embodiment, the surface aberrations of the microapertures face opposite of the surface aberrations of the macroapertures on the nonwoven layer. In such an instance, it is believed that the macroapertures maximize the overall wetting/lathering of the article by the three-dimensional thickness formed from the surface aberrations which are under constant compression and decompression during the use of the article thereby creating lathering bellows.

In any case, the nonwoven layer comprising a formed film preferably has at least about 100 apertures/cm², more preferably at least 500 apertures/cm², even still more preferably at least about 1000 apertures/cm², and most preferably at least about 1500 apertures/cm² of the substrate. More preferred embodiments of the present invention include a nonwoven layer which has water flux rate of from about 5 cm³/cm²-s to about 70 cm³/cm²-s, more preferably from about 10 cm /cm²-s to about 50 cm /cm -s and most preferably from about 15 cm³/cm²-s to about 40 cm³/cm²-s.

Suitable formed films and formed film-containing composite materials useful in the nonwoven layer of the present invention include, but are not limited to, those disclosed in U. S. Patent No. 4,342,314 issued to Radel et al. on August 3, 1982, commonly assigned co- pending application U. S. Serial No. 08/326,571 and PCT Application No. US95/07435, filed June 12, 1995 and published January 1 1 , 1996, and U. S. Patent No. 4,629,643, issued to Curro et al. on December 16, 1986, each of which is incorporated by reference herein in its entirety. Furthermore, the nonwoven layer may be a formed film composite material comprising at least one formed film and at least one nonwoven wherein the layer is vacuum formed. A suitable formed film composite material includes, but is not limited to, a vacuum laminated composite formed film material formed by combining a carded polypropylene nonwoven having a basis weight of 30 gsm with a formed film. Furthermore, each of the layers of the articles as well as the articles themselves may be made into a wide variety of shapes and forms including flat pads, thick pads, thin sheets, ball- shaped implements, irregularly shaped implements. The exact size of the layers will depend upon the desired use and characteristics of the article and may range in surface area size from about a square inch to about hundreds of square inches.. Especially convenient layer and article shapes include, but are not limited to, square, circular, rectangular, hourglass, mitt-type or oval shapes having a surface area of from about 5 in² to about 200 in², preferably from about 6 in² to about 120 in², and more preferably from about 15 in² to about 100 in², and a thickness of from about 0.5 mm to about 50 mm, preferably from about 1 mm to about 25 mm, and more preferably from about 2 mm to about 20 mm.

METHODS OF MANUFACTURE The present invention may be made by using any of the typical methods known to those skilled in the art to achieve the selected compositions and articles. For example methods to make solid antiperspirant sticks are disclosed in Gels and Sticks Formulary, 99 Cosmetics & Toiletries 77-84, 1984; herein incorporated by reference. Methods found particularly useful follow below: Combine the gelling agent and the liquid base material into a vessel equipped with a heat source. Heat the mixture to between about 80 C and about 130°C with stirring, until the mixture forms a homogeneous, molten solution. Preferably, the homogeneous, molten solution is allowed to cool to a mixing temperature; typically between about 65 C and 120 C. Alternatively, the mixture may simply be heated to the mixing temperature until the mixture forms a homogeneous, molten solution. This alternative method, however, typically takes longer than simply overheating and then cooling. Add the antiperspirant active and other ingredients, such as the particulate solid, fragrances and colors, into the homogeneous, molten solution in the above vessel with stirring. Allow the mixture to cool until it begins thickening and then pour the mixture into containers allowing them to cool to ambient temperature. Although not preferred, the antiperspirant active may alternatively be added along with the gelling agent and the liquid base material in the first step.

METHOD FOR CONTROLLING SOLID DEPOSITION

The methods of the present invention help improve the deposition efficiency of a hard, waxy composition onto skin or other applied surface, wherein such method comprises the step of incorporating, into a hard, waxy or other similar composition, a particulate solid having particle size distribution, wherein the particle size distribution is characterized by a mode particle size of greater than about 20μm, preferably greater than about 25 μm, and more preferably greater than about 30μm and less than about lOOμm, preferably less than about 75μm, and more preferably less than about 50μm.

The methods of the present invention may be applied to hard, waxy compositions further comprising a separate particulate solid component having a mode particle size of less than about 12μm. It has been found that particulate solids having a mode particle size of less than 12μm do not disrupt the crystal structure enough to increase deposition of the hard, waxy composition. Therefore, the incorporation of the particulate solids having a mode particle size of from about 20μm to lOOμm to such a composition, in addition to the other separate particulate solid component, will again increase the deposition of the composition on the skm

The methods of the present invention also includes a method of providing improved deposition of a hard, waxy or other similar composition to the skin or other applied surface, wherein the method comprises the step of applying the compositions described herein to the skin or other applied surface

The methods of the present invention also includes a method of providing improved deposition of an antiperspirant stick composition to the underarm area of skin, wherein the antiperspirant stick compositions described herein are applied to the underarm in an amount effective to inhibit or control underarm perspiration and/or underarm odor, such amount typically ranging from about 0 1 gram per axilla to about 1 0 gram per axilla, more typically from about 0 1 gram to about 0 5 gram

EXAMPLES The following examples further describe and demonstrate embodiments within the scope of the present invention These examples are solely for the purpose of illustration and are not to be construed as limitations of the present invention as many variations are possible without departing from the spirit or scope thereof The concentration of the components in the examples below are expressed by total weight of the composition, unless otherwise specified Each of the exemplified compositions contain solid particulates having the essential particle size and other measured distribution characteristics as defined herein, including a d90 value to mode particle size of from about 2 0 to about 10 0, and a mode particle size of some or all of the solid particulates of at least 20 μm Each of the exemplified compositions is applied to the appropriate applied surface to provide improved deposition of the product composition onto that surface

1) GP-1 (N-Lauroyl-L-glutamic acid- di-n-butyl amιde)supplιed by Ajinomoto, Inc

2) Dow Coming 245 Fluid-cyclic polydimethylsiloxane

3) Dow Corning 556 Fluid

4) Benol White Mineral Oil supplied by Witco Chemical Corp

5) polyisobutene supplied by Amoco Chemical Company

6) propylene glycol dicaprate/dicaprylate supplied by Capital City Products

7) Fmsolv TN supplied by Finetex

8) Schercemol DIS supplied by Scher Chemicals Inc

9) Aluminum Zirconium Tnchlorhydrex Glycinate Complex Supplied by Westwood Chemical Co

10) Westchlor DM200 supplied by Westwood Chemical Co

Table 2: Anti ers irant Sticks

2) Dow Corning 245 Fluid - cyclic polydimethylsiloxane

3) Dow Corning 244 Fluid - cyclic polydimethylsiloxane

4) Ethylflo 364 supplied by Ethyl Corp.

5) Performathox 450 supplied by New Phase Technologies

6) Performathox 480 supplied by New Phase Technologies

7) Performacol 425 supplied by New Phase Technologies

10 8) Unilin 700 supplied by Petrohte MISSING AT THE TIME OF PUBLICATION

Example 20 and 21

Table 4: Moisturizing wipe (e.g., moisturizin bab wi e)

The wipe is prepared by heating the stearyl alcohol and petrolatum to 70°C, milling the zinc oxide into the mixture, stirring in the particulate solids (microthene powder). About 0.2 grams of the resulting formulation per gram of wipe substrate is slot coated along the substrate length. The resulting wipe provides improved deposition onto the skin of the substrate formulation.

Example 22

Substrate - Permeable, fusible web comprised of low-melting heat-sealable polyamide fibers The moisturizing baby cloth or wipe is prepared by heating the stearyl alcohol and petrolatum to 70°C, milling the zinc oxide into the heated mixture, and then adding and mixing the particulate solids (microthene powder) into the mixture. About 0.2 grams of the resulting formulation is per gram of wipe substrate along the substrate length, with a slot coater. The resulting wipe provides improved deposition onto the skin of the formulation that was applied during processing to the wipe substrate.

Example 23

Table 6: Moisturizin Cleansin Wi e

Substrate - 70 gsm web comprised of 3 denier hydroentangled polyester fibers. The wipe is prepared by melting all of the hydrophobic components together, stirring in pre-dispersed microfine titanium dioxide particles, and then stirring in the particulate solids (microthene powder). The resulting formulation is slot coated onto one side of the substrate at 0.5 grams per sheet.

Claims

WHAT IS CLAIMED IS:

1 An antiperspirant stick composition comprising a) from 1% to 35% by weight of a suspending or thickening agent, b) from 10% to 90% by weight of a carrier liquid comprising a volatile cyclomethicone, and c) from about 5% to about 35% by weight of a particulate antiperspirant active selected from the group consisting of zirconium salts, aluminum salts, and combinations thereof, wherein the particulate antiperspirant active has a particle size distribution characterized by a ratio of a d90 value to mode particle size of from 2 0 to 100

2 An antiperspirant stick composition according to Claim 1 wherein the ratio of the d90 value to the mode particle size is from 2 0 to 4 5

3 An antiperspirant stick composition according to any one of the preceding claims wherein the particulate antiperspirant active is further characterized by a) a first particulate antiperspirant active having a particle size distribution characterized by a mode particle size of less than 12μm, and b) a second particulate antiperspirant active having a particle size distribution characterized by a mode particle size greater than 20μm, and wherein the weight ratio of the first to second particulate antiperspirant active is greater than 6 1

4 An antiperspirant stick composition according to any one of the preceding claims wherein the suspending or thickening agent comprises castor wax

5 An antiperspirant stick composition according to any one of the preceding claims wherein the suspending or thickening agent comprises stearyl alcohol

6 A method to improve the deposition of a hard, waxy composition to the skin or other applied surface upon application, said method comprising incorporating, into a hard, waxy composition, a particulate solid having a particle size distribution characterized by a mode particle size of from 20μm to lOOμm

7 A method according to Claim 6 wherein the method further comprises incorporating into the composition a second particulate, wherein the second particulate solid has a particle size distribution characterized by a mode particle size of less than 12μm

8 A method according to Claim 6 wherein the hard, waxy composition is applied from a woven or non-woven substrate intended for contact with human skin 9 A method according to Claim 8 wherein the substrate is selected from the group consisting of diapers, feminine hygiene products, cleansing wipes, and non-cleansing wipes

10 An article of manufacture comprising a substrate and a hard, waxy composition comprising a particulate solid having a particle size distribution characterized by a mode particle size of from 20μm to 1 OOμm, wherein the substrate is a woven or non-woven material selected from the group consisting of diapers, feminine hygiene products, cleansing wipes, and non-cleansing wipes