Abstract:
A nail cleanser containing sodium ethylenediamine tetraacetic acid, urea and water. When applied to nails it removes various stains such as tobacco, nail pigment, shoe polish, furniture polish and hair dyes.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A nail cleanser for nails on the human hand for the purpose of removing various types of stains. 
     2. Description of the Prior Art 
     Nails are a prideful accouterment of American females. They assidously file, shape, buff, oil and polish them in order to make them attractive. However, the appearance of nails is frequently spoiled by the presence of stains. This, of course, is particularly true where a clear polish is used or no polish at all is applied. Nails are notoriously porous and become more so with advancing age. This porousity increases their tendency to readily stain. The stains come from various sources. A primary source is nicotine from handling lighted cigarettes. Nails also pick up stains from various chemicals that are handled by women in their homes and occupations. In addition, nails yellow with age. This is believed to be caused by melamine, a brown pigment synthesized in the body by normal biological processes and carried up into the nails from the nail beds. Sometimes the stains appear as spots and sometimes as an overall coloration which permeates the nails or upon occasion only is present at the outer surfaces of the nails. It would be most desirable to remove such stains but to date no satisfactory cosmetic stain remover has been marketed, to the best of applicant&#39;s knowledge. The only relevant material that has been observed is an article in the Chemical Formulary of 1951 at volume IX page 91 where various bleaches are disclosed for finger nails. These, however, are not general purpose nail cleansers. Applicant also is aware of the following patents which disclose compositions including some of the chemical ingredients of the instant nail cleanser. However, the components are not used in the correct proportions for nail cleansing and indeed include many other chemical ingredients, all for purposes other than that of removing stains: 
     U.S. Pat. No. 3,694,366 
     U.S. Pat. No. 3,708,437 
     U.S. Pat. No. 3,957,967 
     U.S. Pat. No. 4,115,293 
     SUMMARY OF THE INVENTION 
     Purpose of the Invention 
     It is an object of the invention to provide a nail cleansing composition of the character described which is simple and inexpensive and which upon application to the nails and removal within a short period of time will remove stains. 
     It is another object of the invention to provide a nail cleanser of the character described which is easy to use and requires no special instructions for its application. 
     It is another object of the invention to provide a nail cleanser of the character described which leaves the nails in good condition to receive subsequent application of nail cosmetics such for instance as clear or opaque nail polishes. 
     It is another object of the invention to provide a nail cleanser of the character described which has no detrimental effects on the nails, the cuticles or the adjacent skin. 
     It is another object of the invention to provide a nail cleanser of the character described which is non-allergenic and non-toxic. 
     It is another object of the invention to provide a nail cleanser of the character described which includes chelating agents as necessary ingredients and which further includes conventional cosmetic additives such as thickeners, preservatives, texturizing agents and abrasives. 
     It is another object of the invention to provide a nail cleanser of the character described which does not include among its ingredients any unstable or potentially explosive chemicals such as oxidizers. 
     Other objects of the invention in part will be obvious and in part will be pointed out hereinafter. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The nail cleanser of the present invention is characterized by the inclusion of essential ingredients present within prescribed critical ranges, by the further necessary inclusion of a liquid carrier for these ingredients and by the optional inclusion of various additives whose presence, although desirable for maximum efficiency of the cleanser, for ease of use and for various cosmetic and odoriferous purposes, is not essential. The necessary ingredients are: Firstly, a particularly effective chelating agent and secondly a chemical which is a milder chelating agent and desirably also is a solubilizing agent. Specifically the first chelating agent, i.e. the one having the higher effectiveness, is selected from a group consisting of ethylenediamine tetraacetic acid, phytol, phytic acid, nitrilo-triacetic acid, diethylene triamino pentaacetic acid, sodium tripolyphosphates and metaphosphate, sodium hexamethaphosphate, trisodium phosphate and ethylene diamino tetraacetic acid. The preferred first chelating agent is an alkali metal salt of ethylenediamine tetraacetic acid, for example sodium ethylenediamine tetraacetic acid. For the second, i.e. milder, chelating agent urea is employed or a substitute therefor, such as allantoin, penthenol and aloe vera extract. 
     Although the present invention is not to be so limited it is believed that the new cleansing agent acts on stains in nails by complexing the metal ions that are present in most stains and thereby rendering the stain leuco, i.e. colorless. The metal ions thus extracted become solubilized by the chelating agent and thereupon form a soluble ingredient of the cleansing agent. Subsequently they leave the nail with the cleansing agent when the cleansing agent is removed. The second, i.e. milder, chelating agent is believed to assist in the extraction and solubilization of the metal ions and in general to exert a solubilizing effect on organic staining material so as to aid in removing it from the nails. 
     The liquid carrier is of course a necessary ingredient. Various liquid carriers can be used and desirably they are such that the first and second necessary ingredients are soluble or dispersible and suspendable therein. Typical acceptable liquid carriers are water, liquid alcohols and acetone. In general the liquid carrier desirably is inexpensive and water therefore is the carrier of choice. 
     The critical range for the first chelating agent is from about 1 percent to about 30 percent by weight of the nail cleanser. The critical range for the second chelating agent is from about 1 percent to about 30 percent by weight of the nail cleanser. The critical range for the liquid carrier is from about 40 percent to about 80 percent by weight of the nail cleanser. The preferred ranges for these three constituents are: for the first chelating agent about 1 percent to about 3 percent, for the second chelating agent from about 4 percent to about 6 percent and for the liquid carrier from about 70 percent to about 80 percent of the cleanser. 
     The foregoing three constituents are the constituents of which the liquid carrier essentially consists. 
     In addition to the essential constituents there are as mentioned earlier a number of desirable additives, for example a mild abrasive such as silica, diatomaceous earth and talc in an amount up to about 5 percent, preferably from about 1 to about 3 percent of the cleanser, to improve the texture hydrolized animal protein up to 2 percent, and preferably from about 0.1 percent to about 0.5 percent of the cleanser, laneth-10 acetate up to about 10 percent, preferably from about 1 percent to about 3 percent of the cleanser and sorbitan sesquioleate up to about 5 percent, preferably from about 1 percent to about 3 percent of the cleanser, a thickener such as cellulose gum, hydroxy ethyl cellulose, Irish moss, tragacanth and other mucilages, and alkali metal salts of polyacrylic acid up to about 3 percent and preferably from about 1 percent to about 3 percent of the cleanser, a solubilizing agent for the various constituents in the liquid carrier such as propylene glycol and ethylene glycol, these materials being particularly desirable constituents and being present in an amount between about 5 percent and about 25 percent, desirably between about 4 percent and about 6 percent of the cleanser; a preservative such as methyl paraben and propyl paraben, the methyl paraben being present in an amount from about 0.10 percent to about 0.5 percent of the cleanser, desirably from about 0.10 percent to about 0.20 percent by weight of the cleanser, the propyl paraben being present in an amount of from about 0.04 percent to about 0.10 percent, desirably from about 0.04 percent to about 0.06 percent of the cleanser, and a fragrance, typically up to 0.5 percent of the cleanser and desirably from about 0.1 percent to about 0.3 percent of the cleanser. All percentages mentioned are by weight. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As mentioned above, certain components of the nail cleanser necessarily are present, others are optional. The necessary components are a first chelating agent which is a relatively active one, its activity being in comparison to the activity of a second chelating agent which is the second necessary ingredient of the nail cleanser formulation. The third necessary ingredient is a liquid carrier for the first chelating agent and for the second chelating agent. The second chelating agent also functions as a solubilizing agent for various constituents of the nail cleanser. 
     The optional ingredients are ingredients which are conventionally employed in many other cosmetic formulations for well known functions. These include: one or more mild abrasives, one or more texturizing agents, one or more thickeners, one or more solubilizing agents in addition to the second chelating agent, oen or more preservatives and one or more fragrances. 
     For the first chelating agent the material of choice is ethylene diamine tetraacetic acid and in particular an alkali metal salt thereof. Other compounds that can be used for the first chelating agent are: phytol, phytic acid, nitrilo-triacetic acid, diethylene triamino pentaacetic acid, sodium tripolyphosphates, sodium metaphosphate, sodium hexamethaphosphate, trisodiumphosphate and ethylene diamino tetraacetic acid. The preferred second ingredient, i.e. the milder chelating agent is urea. Other milder chelating agents which can be used in place of the urea are: allantoin, d-penthenol, aloe vera extract and urea precursors. 
     The third and last necessary ingredient is a liquid carrier which will solvate or disperse the sundry ingredients of the nail cleanser. The preferred carrier is water since it will perform the function required and is the least costly. In place of or in addition to water, liquid alcohols or acetone can be used. 
     Insofar as the optional constituents are concerned they constitute the following: 
     A mild abrasive such as silica, diatomaceous earth and talc. 
     A texturizing material such as a hydrolized animal protein, laneth-10 acetate and sorbitan sesquioleate. 
     A thickener such as cellulose gum, hydroxy ethyl cellulose,Irish moss, tragacanth, mucilage and alkali salts of polyacrylic acid. 
     A solubilizing agent such as propylene glycol and ethylene glycol. 
     A preservative such as methyl paraben and propyl paraben. 
     A fragrance. 
     The preferred optional materials that are employed are silica, hydrolized animal protein, laneth-10 acetate, sorbitan sesquioleate, cellulose gum, glycol, methyl paraben, propyl paraben and a fragrance. In addition it is desirable also to include a small amount of acetone to assist in solubilization. 
    
    
     Set forth below is a preferred formulation for a nail cleanser embodying the invention. 
     
         ______________________________________            PERCENTAGE BY WEIGHTINGREDIENTS      OF NAIL CLEANSER______________________________________Water            76.05Disodium EDTA    2.00Silica           1.50Hydrolyzed Animal Protein            0.10Laneth-10 Acetate            2.00Acetone          4.50Sorbitan Sesquioleate            1.50Cellulose Gum    2.00Urea             5.00Propylene Glycol 5.00Methyl Paraben   0.10Propyl Paraben   0.05______________________________________ 
    
     It will be understood that the invention is not restricted to the particular compounds listed above inasmuch, as mentioned previously, different ingredients may be substituted for the ones listed; moreover the formulation can be varied considerably and to indicate the range of variations there are set forth below the ideal range by weight and the maximum range by weight for each of the mentioned ingredients. 
     
         ______________________________________       MAXIMUM       RANGE BY WEIGHT IDEAL RANGEINGREDIENTS OF NAIL CLEANSER                       BY WEIGHT______________________________________Water       40-80%          70-80%Disodium EDTA        1-30%          1-3%Silica      0-5%            1-3%HydrolyzedAnimal Protein       0-2%            0.10-0.50%Laneth-10 Acetate        0-10%          1-3%Acetone      0-20%          4-6%SorbitanSesquioleate       0-5%            1-3%Cellulose Gum       0-3%            1-3%Urea         1-30%          4-6%Propylene Glycol        5-25%          4-6%Methyl Paraben       0.10-0.50%      0.10-0.20%Propyl Paraben       0.03-0.10%      0.04-0.06%Fragrance   0.0-0.5%        0.1-0.3%______________________________________ 
    
     The pH of the nail cleanser should range between about 6 and about 8 and preferably is substantially neutral, that is to say 7. 
     The nail cleanser is used simply by applying it to a nail, after the removal of nail polish if present, leaving the cleanser on for a short period, for example about ten seconds to about one half minute, and wiping it off with a rag. It is not necessary to clean off any residue. The small amount of acetone in the cleanser will remove any trace of nail polish that is present. 
     The viscosity of the nail cleanser can vary quite widely. The only critical factor is that it be sufficient viscous to remain on the nail for a time sufficient to remove the stain, such time having been indicated above. 
     A typical satisfactory viscosity is 11,000 cps in which form it is a cream. 
     A study performed on a 100 subjects showed generally excellent results. In the study the preferred nail cleanser formulation was used. It was applied to the nails with a brush after removal of nail polish and left on between about a quarter to half a minute. The nails of people of various ages were cleaned in the aforesaid manner. All the nails of each subject were thus treated. In some instances the nail cleanser was applied more than once. Set forth below are the results of the study: 
     
         __________________________________________________________________________SUBJECT                  HOW MANYNUMBER AGE TYPE OF STAIN  APPLICATIONS                             RESULTS__________________________________________________________________________1     53  Nail Pigment(Yellow stain)                    4        Excellent2     52  Nail Pigment(Yellow stain)                    2        Excellent3     52  Nail Pigment(Yellow stain)                    2        Excellent4     49  Shoe polish    4        Excellent5     37  Nail pigment(Yellow stain)                    1        Excellent6     43  Tobacco stain  1        Excellent7     39  Nail pigment(Yellow stain)                    2        Excellent8     40  Nail pigment(yellow stain)                    2        Excellent9     34  Nail pigment(yellow stain)                    1        Excellent10    34  Nail pigment(yellow stain)                    4        Excellent11    34  Nail pigment(yellow stain)                    2        Excellent12    34  Nail pigment(yellow stain)                    1        Excellent13    38  Nail pigment(yellow stain)                    1        Excellent14    31  Nail pigment(yellow stain)                    3        Excellent15    31  Nail pigment(yellow stain)                    2        Excellent16    34  Tobacco stain  1        Excellent17    30  Nail pigment(yellow stain)                    2        Excellent18    30  Nail pigment(tobacco stain)                    1        Excellent19    39  Tobacco stain/shoe polish                    2        Excellent20    40  Tobacco stain/shoe polish                    2        Excellent21    36  Tobacco stain/furniture polish                    1        Excellent22    27  Nail pigment(yellow stain)                    1        Excellent23    30  Nail pigment(yellow stain)                    1        Excellent24    27  Tobacco stain  2        Excellent25    58  Nail pigment(yellow stain)                    1        Excellent26    62  Nail pigment(yellow stain)                    1        Excellent27    36  Nail pigment/tobacco stain                    2        Excellent28    22  Nail pigment(yellow stain)                    1        Excellent29    52  Dye            1        Excellent30    62  Nail stain/tobacco stain                    1        Excellent31    49  Iodine/shoe polish/tobacco                    3        Excellent32    53  Nail pigment(yellow stain)                    1        Excellent33    54  Nail pigment(yellow stain)                    1        Excellent34    47  Nail pigment(yellow stain)                    2        Excellent35    47  Nail pigment(yellow stain)                    1        Excellent36    55  Nail pigment(tobacco stain                    3        Excellent37    47  Other          1        Excellent38    55  Nail pigment/tobacco stain                    4        Excellent39    50  Shoe polish    1        Excellent40    38  Nail pigment/tobacco stain                    4        Excellent41    14  Nail pigment(yellow stain)                    1        Excellent42    35  Nail pigment/tobacco stain                    1        Excellent43    33  Nail pigment/tobacco stain                    2        Excellent44    36  Nail pigment(yellow stain)                    2        Excellent45    46  Nail pigment(yellow stain)                    2        Excellent46    66  Tobacco stain  1        Excellent47    37  Furniture stain                    1        Excellent48    21  Hair dye       2        Excellent49    30  Nail pigment(yellow stain)                    1        Excellent50    28  Nail pigment/tobacco stain                    1        Excellent51    41  Shoe polish    1        Excellent52    51  Nail pigment(yellow stain)                    2        Excellent53    43  Nail pigment(yellow stain)                    1        Excellent54    39  Nail pigment(yellow stain)                    1        Excellent55    48  Nail pigment(yellow stain)                    2        Excellent56    55  Nail pigment(yellow stain)                    2        Excellent57    53  Nail pigment(yellow stain)                    1        Excellent58    53  Nail pigment(yellow stain)                    1        Excellent59    33  Nail pigment(yellow stain)                    2        Excellent60    47  Nail pigment(yellow stain)                    1        Excellent61    52  Nail pigment(yellow stain)                    1        Excellent62    57  Nail pigmen/tobacco stain                    4        Excellent63    32  Tobacco stain  1        Excellent64    34  Tobacco stain  1        Excellent65    26  Nail pigment/tobacco stain                    2        Excellent66    24  Nail pigment(yellow stain)                    1        Excellent67    35  Nail pigment(yellow stain)                    4        Excellent68    29  Nail pigment(yellow stain)                    1        Excellent69    35  Tobacco stain  1        Excellent70    37  Nail pigment(yellow stain)                    2        Excellent71    45  Nail pigment(yellow stain)                    4        Good-slight                             yellow tinge                             remained on                             4 fingers72    34  Nail pigment/tobacco stain                    3        Excellent73    47  Nail pigment(yellow stain)                    4        Good-slight                             yellow tinge                             remained on                             5 fingers74    56  Nail pigment(yellow stain)                    1        Excellent75    59  Nail pigment(yellow stain)                    1        Excellent76    44  Nail pigment(yellow stain)                    1        Excellent77    50  Nail pigment(yellow stain)                    1        Excellent78    39  Nail pigment(yellow stain)                    1        Excellent79    53  Tobacco stain  2        Excellent80    31  Nail pigment(yellow stain)                    1        Excellent81    36  Nail pigment(yellow stain)                    1        Excellent82    14  Nail pigment(yellow stain)                    1        Excellent83    54  Nail pigment(yellow stain)                    5        Good-slight                             stain re-                             mained on all                             fingers84    18  Nail pigment/tobacco stain                    1        Excellent85    22  Nail pigment/tobacco stain                    1        Excellent86    47  Tobacco stain  2        Excellent87    57  Nail pigment(yellow stain)                    1        Excellent88    29  Nail pigment(yellow stain)                    1        Excellent89    39  Nail pigment(yellow stain)                    1        Excellent90    37  Nail pigment(yellow stain)                    1        Excellent91    24  Nail pigment(yellow stain)                    1        Excellent92    21  Nail pigment/tobacco stain                    1        Excellent93    27  Tobacco stain  1        Excellent94    25  Nail pigment(yellow stain)                    1        Excellent95    22  Nail pigment(yellow stain)                    1        Excellent96    25  Tobacco stain  1        Excellent97    26  Nail pigment(yellow stain)                    1        Excellent98    24  Nail pigment(yellow stain)                    1        Excellent99    28  Nail pigment(yellow stain)                    1        Excellent100   23  Tobacco stain  1        Excellent__________________________________________________________________________ 
    
     It thus will be seen that there has been provided a nail cleanser which achieves the various objects of the invention and is well adapted to meet the conditions of practical use. 
     As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth it is to be understood that all matter herein described is to be interpreted as illustrative and not in a limited sense.