CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U. S. Utility Application 14/819,539 filed August 6, 2015 and entitled "ANTIPERSPIRANT COMPOSITIONS WITH MASKING AGENTS AND METHODS FOR PRODUCING THE SAME", which is incorporated herein.

TECHNICAL FIELD

[0002] The technical field generally relates to antiperspirant compositions and methods for producing antiperspirant compositions, and more particularly relates to antiperspirant compositions with masking agents and methods for producing such antiperspirant compositions.

BACKGROUND

[0003] Antiperspirant compositions are popular personal care products used to reduce or eliminate perspiration and body odor caused by perspiration. Antiperspirant products are available in many forms, including sticks, aerosols, gels, emulsions, roll-ons, and the like, and are used by many people. The antiperspirant compositions include an active antiperspirant agent that reduces or prevents the secretion of perspiration by blocking or plugging eccrine glands and/or the apocrine glands, otherwise known as sweat glands, such as those located at the underarms. The active antiperspirant agent is typically suspended or dissolved in a carrier that permits the antiperspirant composition to be applied to the skin using a roll on, aerosol, or other application device. Upon application, the carrier coats the skin or evaporates, and the active antiperspirant agent remains to form plugs in the eccrine and/or apocrine glands upon expose to moisture. [0004] In some embodiments, the active antiperspirant agent is visible as a white residue after the antiperspirant composition is applied and after the carrier liquid has evaporated in antiperspirant composition that employ a volatile carrier. However, visible white residues have been noticed in formulations with a non-volatile carrier as well. The white residue is objectionable for many uses.

[0005] Accordingly, it is desirable to provide antiperspirant compositions and methods for producing antiperspirant compositions that leave no visible residue upon application, or that have reduced visibility of the active antiperspirant agent residue after application while still leaving active antiperspirant agent present on the skin to reduce or eliminate perspiration. Other desirable features and characteristics of the present embodiment will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.

BRIEF SUMMARY

[0006] Antiperspirant compositions with masking agents and methods for producing the same are provided. In an embodiment, an antiperspirant composition includes an active antiperspirant agent with an active agent refractive index. The antiperspirant composition also includes a masking agent with a masking agent refractive index that is greater than the active agent refractive index by about 0.3 percent or more. The antiperspirant composition includes a carrier, and also includes water at about 3 weight percent or less.

[0007] In another embodiment, a method is provided for producing an antiperspirant composition. An active antiperspirant agent, a carrier, and a masking agent are combined to form the antiperspirant composition. The active antiperspirant agent has an active agent refractive index, and the masking agent has a masking agent refractive index. The masking agent refractive index is greater than the active agent refractive index by about 0.7 percent or more. The antiperspirant composition is mixed, where the antiperspirant composition includes about 3 weight percent water or less, based on the total weight of the antiperspirant composition. [0008] A method for preparing an antiperspirant composition is provided in yet another embodiment. A masking agent, an active antiperspirant agent, and a carrier are combined, wherein the masking agent is included at a masking agent concentration sufficient to mask an active antiperspirant agent residue. The active antiperspirant agent residue is masked when an active spot and a masking spot may be applied to a black substrate. The active spot has an active L value that is greater than a masking L value of the masking spot. The active spot has a test quantity of the active antiperspirant agent per square centimeter and about 0.01 grams or less of the masking agent per square centimeter. The masking spot has at least the test quantity of the active antiperspirant agent per square centimeter, and about one half or more of the test quantity of the masking agent per square centimeter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:

[0010] FIG. 1 is a schematic representation of an antiperspirant composition preparation apparatus during preparation of an antiperspirant composition in accordance with an embodiment;

[0011] FIG. 2 is a schematic representation of a portion of a method of preparing an antiperspirant composition including formation of an active spot and a masking spot for measurement of L values in accordance with an embodiment; and

[0012] FIG. 3 is a graph illustrating L values measured during testing of various antiperspirant compositions.

DETAILED DESCRIPTION

[0013] The following detailed description is merely exemplary in nature and is not intended to limit the various embodiments of the antiperspirant compositions and methods of preparing the same, or the application and uses antiperspirant compositions. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0014] The various embodiments contemplated herein relate to personal care antiperspirant compositions with an active antiperspirant agent, a carrier, and a masking agent, where the masking agent reduces or eliminates the appearance of a residue that may otherwise result from the active ingredient upon application of the antiperspirant composition. The residue is typically white in color, but other colors are possible in some embodiments. The antiperspirant composition may also include deodorant or other fragrances, emollients, antioxidants, surfactants, thickeners, diluents, and the like. The antiperspirant composition may be provided in a variety of formulations, including but not limited to roll-ons, aerosols, pumps, sprays, liquids, lotions, creams, sticks, and soft solids, among others. Exemplary formulations for roll-on antiperspirant compositions are provided in greater detail below, but similar compositions may be used with other types of applicators.

[0015] Referring to FIG. 1, the antiperspirant composition 10 includes a plurality of components, including a carrier 12, an active antiperspirant agent 14, and a masking agent 16. The ingredients are combined to form the antiperspirant composition 10. The carrier 12 is a liquid suitable for suspending the active antiperspirant agent 14. In an exemplary embodiment, the carrier 12 is a non-aqueous liquid. As used herein, the term "non-aqueous" means a composition having water at about 5 weight percent or less, or about 3 weight percent or less, or about 1 weight percent or less in various embodiments, with all amounts being based on the total weight of the composition. The total weight of the composition may refer to the carrier 12 when discussing the carrier 12, or it may refer to the antiperspirant composition 10 when discussing the antiperspirant composition 10, and so forth. Non-aqueous embodiments of the antiperspirant composition 10 may be free of an emulsion, so there are not two separate liquid phases present in the antiperspirant composition 10. As used herein, the term "liquid" means a material that is in the liquid state at temperatures ranging from about 10 degrees centigrade (°C) to about 50 °C, and pressures from about 0.5 bars to about 1.5 bars. In an exemplary embodiment, water is not soluble in the carrier 12, such that the solubility of water in the carrier is about 0.1 grams of water or less per 100 milliliters of carrier 12

[0016] Exemplary embodiments of the carrier 12 include liquid siloxanes and/or non- polar hydrocarbons having a boiling point of about 90 degrees centigrade (°C) or greater, but some carriers 12 may include components with a boiling point of less than 90 °C. Specific examples of carriers 12 include cyclotetrasiloxane, cyclopentasiloxane, cyclohexasiloxane, polydimethyl siloxane, liquid alkanes having 7 to 15 carbon atoms, hexamethyl disiloxane, cyclomethicone, polyhydric alcohols having 3-6 carbon atoms and 2-6 hydroxy groups (including propylene glycol), alcohols having from 2 to 10 carbon atoms (including ethanol), fatty alcohol esters, fatty acid esters, fatty amides, polyethylene glycols, ethylene and/or propylene glycol ethers having 4 to 15 carbons, propylene carbonate, caprylic/capric triglyceride, water, ethanol, isopropyl myristate, and mixtures thereof. In particular, the carrier 12 includes more than one chemical compound in some embodiments, such as a combination of cyclopentasiloxane and cyclohexasiloxane. The term "fatty" is intended to include hydrocarbon chains of about 6 to 10 carbon atoms. In alternate embodiments, the carrier 12 may be an emulsion including water and non-polar liquids, such as siloxanes or paraffins. The antiperspirant composition 10 includes the carrier 12 at concentrations suitable to suspend the active antiperspirant agent 14, such as concentrations of from about 40 weight percent to about 80 weight percent, or from about 50 weight percent to about 70 weight percent, or from about 50 weight percent to about 60 weight percent. All weight percentages described herein are based on the total weight of the antiperspirant composition 10, unless otherwise specified.

[0017] The antiperspirant composition 10 includes at least one active antiperspirant agent 14, which is typically a metal salt. Some active antiperspirant agents 14 that may be used include astringent metallic salts, especially inorganic and organic salts of aluminum, zirconium, and zinc, as well as mixtures thereof. Exemplary aluminum- containing and/or zirconium-containing salts or materials include aluminum halides, aluminum chlorohydrates, aluminum hydroxyhalides, zirconyl oxyhalides, zirconyl hydroxyhalides, and mixtures thereof. Exemplary aluminum salts include those having the general formula Al2(OH) _a Clb x (H ₂ 0), wherein a is from 2 to about 5; the sum of a and b is about 6; x is the number of water molecules included in the complex and ranges from about 1 to about 6; and wherein a, b, and x may have non-integer values. Exemplary zirconium salts include those having the general formula ZrO(OH)2- _a Cl _a x (H ₂ 0), wherein a is from about 1.5 to about 1.87, x is from about 1 to about 7, and wherein a and x may both have non-integer values.

[0018] Some embodiments of the active antiperspirant agent 14 include zirconium salts, such as complexes that additionally contain aluminum and glycine, commonly known as ZAG complexes. These ZAG complexes contain aluminum chlorohydroxide and zironyl hyroxy chloride conforming to the above-described formulas. Specific examples of active antiperspirant agents 14 suitable for use in the various embodiments contemplated herein include aluminum dichlorohydrate, aluminum-zirconium octachlorohydrate, aluminum sesquichlorohydrate, aluminum chlorohydrex propylene glycol complex, aluminum dichlorohydrex propylene glycol complex, aluminum sesquichlorohydrex propylene glycol complex, aluminum chlorohydrex polyethylene glycol complex, aluminum dichlorohydrex polyethylene glycol complex, aluminum sesquichlorohydrex polyethylene glycol complex, aluminum-zirconium trichlorohydrate, aluminum zirconium tetrachlorohydrate, aluminum zirconium pentachlorohydrate, aluminum zirconium octachlorohydrate, aluminum zirconium trichlorohydrex glycine complex, aluminum zirconium tetrachlorohydrex glycine complex, aluminum zirconium pentachlorohydrex glycine complex, aluminum zirconium octachlorohydrex glycine complex, zirconium chlorohydrate, aluminum chloride, aluminum sulfate buffered, and the like, and mixtures thereof. In one embodiment, the active antiperspirant agent 14 is aluminum zirconium pentachlorohydrex. In an exemplary embodiment, the antiperspirant composition 10 includes the active antiperspirant agent 14 in the amount of from about 5 to about 25 wt. % (USP). As used herein, weight percent (USP) or wt. % (USP) of an active antiperspirant agent 14 salt is calculated as anhydrous weight percent in accordance with the U.S.P. method, as is known in the art. This calculation excludes any bound water and glycerin.

[0019] In an exemplary embodiment, the active antiperspirant agent 14 is suspended in the carrier 12 within the antiperspirant composition 10, because the active antiperspirant agent 14 may not be readily soluble in the carrier 12. The antiperspirant composition 10 may be non-aqueous, and the carrier may be relatively non-polar such that the active antiperspirant agent 14 does not ionize and dissolve. Therefore, the active antiperspirant agent 14 may be combined and suspended in the carrier 12 as a powder with an average particle size of from about 1 to about 100 microns.

[0020] The active antiperspirant agent 14 has an active agent refractive index, where the active agent refractive index is based on pure active antiperspirant agent 14 (wherein "pure" means about 99 weight percent or greater) at a temperature of 25 °C and at a wavelength of about 589 nanometers. Refractive indexes referred to herein are at a temperature of 25 °C and a wavelength of about 589 nanometers, unless otherwise indicated. For example, many aluminum salt active antiperspirant agents 14 have a refractive index of about 1.432 to about 1.438. Aluminum zirconium pentachlorohydrex, in particular, has a refractive index of about 1.435.

[0021] As alluded to above, the antiperspirant composition 10 includes the masking agent 16, and the masking agent 16 has a masking agent refractive index. The masking agent refractive index is based on pure masking agent 16, and the masking agent refractive index is greater than the active agent refractive index by about 0.3 percent or more, or by about 0.7 percent or more, or by about 1.0 percent or more in various embodiments. As such, the (masking agent refractive index - active agent refractive index)/(active agent refractive index) is equal to or greater than about 0.003, or about 0.007, or about 0.01 in various embodiments. Therefore, for an example with aluminum zirconium pentchlorohydrex as the active antiperspirant agent 14, an appropriate masking agent refractive index may be identified by solving for X in the following equation: ((X-1.435)/1.435) >0.003, so X is about 1.439 or greater. Therefore, a masking agent 16 with a masking agent refractive index of about 1.439 or greater is an acceptable masking agent 16 in some embodiments. The refractive index for the masking agent 16 is also measured at 25 °C at a wavelength of about 589 nanometers, as mentioned above. In an exemplary embodiment, the masking agent refractive index is from about 1.44 to about 1.50, and the active agent refractive index is less than 1.44. The carrier 12 also has a carrier refractive index. In some embodiments, the carrier refractive index that is less than the active agent refractive index. In an alternate embodiment, a carrier 12 with a carrier refractive index that is greater than the active agent refractive index may serve as the masking agent 16 in the antiperspirant composition 10.

[0022] In some embodiments, the masking agent 16 is a liquid that remains on the skin after application, where the term liquid is defined above. A volatile masking agent 16 may evaporate, so it would no longer be available for masking an active antiperspirant agent residue. Therefore, the masking agent 16 may be non- volatile and have a boiling point of about 230 °C or greater.

[0023] It has been found that an effective amount of masking agent 16 essentially masks or hides the appearance of the active antiperspirant agent residue on a person' s skin. As such, the masking agent 16 is added to produce a masking agent concentration sufficient to mask the active antiperspirant agent residue. The effective amount of masking agent 16 present in the antiperspirant composition 10 may be about ½ or more of the active antiperspirant agent concentration in some embodiments, so in an example with the active antiperspirant agent 14 present at about 20 weight percent, the masking agent 16 may be present at about 10 weight percent or more. In other embodiments, the masking agent 16 is present in the antiperspirant composition 10 at from about 5 to about 20 weight percent, or from about 7 to about 15 weight percent, or from about 10 to about 15 weight percent in various embodiments, with all amounts based on the total weight of the antiperspirant composition 10.

[0024] Specific examples of suitable masking agents 16 for aluminum salt active antiperspirant agents 14 include C 12-15 alkyl benzoate, polypropylene glycol (PPG) 3 benzyl ether myristate, (the number after "PPG" represents the average number of propylene glycol repeat units in the molecule) coconut oil (long or short chain), palm kernel oil (long or short chain), phenyl trimethicone, PPG- 15 stearyl ether and PPG- 14 butyl ether. However, other non-aqueous liquid materials having a refractive index greater than the refractive index of the active antiperspirant agent 14 may be used in alternate embodiments. In some embodiments, more than one molecular compound may be used as the masking agent 16, where each individual molecular compound of the masking agent 16 has a masking agent refractive index greater than the active agent refractive index. The masking agent 16 is soluble in the carrier 12, so the masking agent 16 and carrier 12 form a solution, as opposed to an emulsion that may be formed when insoluble liquids are combined. A masking agent 16 is considered "soluble" in a carrier 12 if the masking agent 16 is soluble at a concentration of about 100 grams or more of masking agent 16 per liter of carrier 12.

[0025] Reference is made to FIG. 2, with continuing reference to FIG. 1. The brightness of a white residue that may be left behind after drying of the antiperspirant composition 10 can be measured with a colorimeter using the L*a*b color space. The L value represents brightness, so the L value is the best measurement of a white residue. The higher the L value, the greater the brightness of an object. White residues tend to increase the brightness of a substrate, especially if the substrate is a black substrate. As mentioned above, the residue may have colors other than white in some embodiments, but the residue generally includes a white component so the L value is a good indicator of the appearance of the residue. A comparative antiperspirant composition that includes the active antiperspirant agent 14, and carrier 12, and any other optional ingredients but without the masking agent 16, may be applied to a black substrate 30 to form an active spot 32. An antiperspirant composition 10 as described herein that includes the active antiperspirant agent 14, carrier 12, and masking agent 16 may be applied to the black substrate 30 to form a masking spot 34. As such, the active spot 32 has a minimum test quantity of active antiperspirant agent 14 per square centimeter, and the active spot 32 is essentially free of masking agent 16, such as having about 0.01 grams or less of masking agent 16 per square centimeter. In an exemplary embodiment, the test quantity of active antiperspirant agent 14 is about 0.1 to about 1.0 grams of active antiperspirant agent 14 per square centimeter, but other test quantities may also be used. The masking spot 34 has at least the test quantity of active antiperspirant agent 14, so the masking spot 34 has at least as much active antiperspirant agent 14 as the active spot 32. The masking spot 34 also has about one half of the test quantity or more of masking agent 16 per square centimeter. An active L value 36 can be measured from the active spot 32, and a masking L value 38 can be measured from the masking spot 34. The masking agent 16 masks the residue from the active antiperspirant agent 14, so the active L value 36 is higher than the masking L value 38. The black substrate 30 without any appreciable quantity of active antiperspirant agent 14, carrier 12, or masking agent 16 also has a substrate L value 40, where the active antiperspirant agent 14, carrier 12, and masking agent 16 are present at about 0.01 grams or less per square centimeter on the black substrate 30 where the substrate L value 40 is measured. In an exemplary embodiment, the masking agent 16 is added to the masking agent concentration to effectively mask any residue from the active antiperspirant agent 14. For example, the masking L value 38 may be within about 5 percent of the substrate L value 40.

[0026] The antiperspirant composition 10 may include one or more optional additives 18, in various embodiments. The additional optional additive(s) 18 include, but are not limited to, fragrances, thickeners, surfactants, emollients, dyes or colorants, distributing agents, topical actives, preservatives, processing aids such as wash-off aids or viscosity modifiers, flow agents, bactericides, odor control agents, antioxidants, rheological agents, moisture absorbers, and the like. One or more of the optional additives 18 may be combined with the carrier 12 and included in the antiperspirant composition 10 at from about 0 to about 40 weight percent in an exemplary embodiment. The additive 18 may include one or more of many different categories of additives, and may be included in the antiperspirant composition 10 at a concentration from about 0 to about 25 weight percent, or from about 0.1 to about 25 weight percent, or from about 0.1 to about 5 weight percent in various embodiments, with all amounts based on the total weight of the antiperspirant composition 10. In some embodiments, the antiperspirant composition 10 is non-aqueous, as defined above. Non-aqueous embodiments of the antiperspirant composition 10 may be free of an emulsion, so there are not two separate liquid phases present in the antiperspirant composition 10.

[0027] The antiperspirant composition 10 is formed by combining the various components, including the carrier 12, the active antiperspirant agent 14, the masking agent 16, and the optional additive 18, and mixing. Any suitable form of mixing can be used to combine the ingredients, such as high shear mixing, stirring, agitation, blending, or any combination thereof. An agitator 26 is illustrated for mixing in FGI. 1, but other mixing devices may be used in alternate embodiments. The components may be combined in a wide variety of manners. For example, the active antiperspirant agent 14 may be combined with the carrier 12 and a thickener, such as diester diammonium hexerite clay in a premix, and this may then be combined with the masking agent 16 and other additives in a second mixing operation. Many mixing orders and operations are possible in alternate embodiments.

[0028] The antiperspirant composition 10 is packaged in a container 24 in a variety of manners. The antiperspirant composition 10 may be roll-on, where the container 24 is a roll-on device. The antiperspirant composition 10 may also be packaged as an aerosol, in which case a propellant (not illustrated) is added to the antiperspirant composition 10. Suitable propellants include light hydrocarbons, fluorochlorocarbons, fluorocarbons, or the like. In other embodiments, the antiperspirant composition 10 is packaged in a pump sprayer. In the above embodiments, the antiperspirant composition 10 may be formulated as a flowable liquid, with the active antiperspirant agent 14 suspended. In alternate embodiments, the antiperspirant composition 10 may include a gelling agent, such as sodium stearate, where the antiperspirant is a gel, a stick, or a soft solid. The antiperspirant composition 10 may also be packaged as a lotion or cream. The antiperspirant composition 10 can be applied to the skin of a user, such as in the armpit, when desired.

EXAMPLE

[0029] Reference is made to FIG. 3, with continuing reference to FIGS. 1 and 2. An active antiperspirant agent 14 was combined with a carrier 12 and tested with varying concentrations of potential masking agents 16. The active antiperspirant agent 14 was aluminum zirconium pentachlorohydrex, and the carrier 12 was one or more of cyclopentasiloxane and cyclotetrasiloxane. The active antiperspirant agent 14 was present at 16 weight percent (USP) in the carrier 12 prior to addition of the masking agent 16. Several potential masking agents 16 were added to the carrier 12 and the active antiperspirant agent 14 at varying weight percentages. The L values were measured with a Gardner colorimeter after applying about 3 milliliters of the test antiperspirant composition 10 to a black paper substrate, and allowing the test antiperspirant composition 10 to dry. The results are illustrated in a graph in FIG. 3, where the vertical (Y) axis is the L values measured, and the horizontal (X) axis is the weight percentage of the masking agent 16 in the combined antiperspirant composition 10. The refractive index of the tested active antiperspirant agent 14, aluminum zirconium pentachlorohydrex, is 1.435. The tested potential masking agents 16 are listed below in Table 1, where the "Reference Number" refers to the line for the tested potential masking agent 16 in the graph of FIG. 3. The horizontal line at an L value of 22 is the substrate L value 40 of the black substrate 30, where the black substrate 30 was black construction paper for the tests.

TABLE 1

[0030] As can be seen, the masking L value 38 approaches the substrate L value 40 as the concentration of the masking agent 16 approaches 10 weight percent, but only in embodiments where the masking agent 16 has a refractive index greater than that of the active antiperspirant agent 14. The test results for cyclohexasiloxane and propylene glycol, which have refractive indexes less than that of the active antiperspirant agent 14 aluminum zirconium pentachlorohydrex, illustrate poor masking performance.

[0031] A specific example of an antiperspirant composition 10 is provided in Table 2, below, where the weight percent is based on the total weight of the antiperspirant composition 10. TABLE 2

[0032] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the application in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing one or more embodiments, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope, as set forth in the appended claims.