Abstract:
A bathing preparation comprising: (a) at least one carbonate; (b) at least one organic acid, wherein adipic acid amounts to 70% by weight or more of the total of the organic acid; and (c) at least one highly volatile perfume, is disclosed. The perfume is not vaporized into the air, thus the bathing preparation sustains its aroma in bath water for a prolonged period of time and exerts relaxing and refreshing bathing effects.

Description:
FIELD OF THE INVENTION 
     This invention relates to a bathing preparation containing at least one organic acid and carbonate, characterized in that the vaporization of a perfume on dissolution of the bathing preparation in bath water, together with the bubbling of carbon dioxide gas is inhibited, thereby allowing the perfume to give its odor for a prolonged period of time. 
     BACKGROUND OF THE INVENTION 
     A bathing preparation, which generally comprises a mixture of inorganic salts such as mirabilite, borax, sulfur, sodium chloride and carbonates, together with various additives (for example, perfume, colorant, vegetable extract, organic acid etc.), would impart a preferable odor or color to bath water. Such a preparation would also accelerate the blood circulation by appropriately stimulating the skin to relieve fatigue and to promote metabolism. Among these bathing preparations, bubbling preparations comprising one or more carbonates, together with organic acids, would form bubbles of carbon dioxide gas in bath water thereby to give additional beneficial effects that enhance relaxation and refreshment provided by bathing. 
     In order to further improve the above-mentioned effects, a perfume is usually added to a bathing preparation. However, a problem encountered when using a highly volatile perfume is that the perfume is quickly vaporized, due to, e.g., the bubbling of carbon dioxide gas from the carbonates, which removes the beneficial effect of using the perfume. 
     Attempt to solve this problem include proposals in JP-A-62-223111 and JP-B-52-21573 to encapsulate, or include in a clathrate a perfume so as to prevent the vaporization of the perfume and achieve a sustained odor. (The term &#34;JP-A&#34; as used herein means an &#34;unexamined published Japanese patent application&#34; while the term &#34;JP-B&#34; as used herein means an &#34;examined Japanese patent publication&#34;.) However encapsulation or clathrate inclusion requires a troublesome procedure and additional cost, which makes these methods economically disadvantageous. In addition to these economical disadvantages, it is difficult to form tablets of a bathing preparation comprising an encapsulated perfume. 
     SUMMARY OF THE INVENTION 
     Under these circumstances, we have conducted extensive studies in order to solve the above-mentioned problems. As a result, we have found out that the use of organic acids containing about 70% (by weight, the same will apply hereinafter) or more of adipic acid in a bathing preparation makes it possible to prevent the vaporization of a particular volatile perfumes without requiring any additional specific means, such as encapsulation or clathrate inclusion. 
     Accordingly, the present invention provides a bathing preparation comprising: 
     (a) at least one carbonate; 
     (b) at least one organic acid, wherein adipic acid amounts about 70% by weight or more of the total of the organic acids; and 
     (c) at least one perfume selected from the group consisting of a terpene hydrocarbon having 10 carbon atoms and a formate, an acetate or a propionate of an alcohol having 5 to 10 carbon atoms. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Examples of carbonates to be used in bathing preparations of the present invention include sodium hydrogencarbonate, sodium carbonate, potassium hydrogencarbonate, potassium carbonate, calcium carbonate, magnesium carbonate and sodium sesquicarbonate. These carbonates can be used either alone or a mixture thereof. 
     The content of the carbonate(s) can range from about 5 to about 80%, preferably from about 10 to about 50%, based on the total weight if the bathing preparation. 
     Organic acids to be contained in the bathing preparation of the present invention should comprise 70% or more of adipic acid. Examples of additional organic acids, useful for comprising the remaining portion of the organic acids, include citric acid, succinic acid, malic acid and tartaric acid. When the amount of adipic acid in the organic acid is less than about 70%, the vaporization of the above-mentioned highly volatile perfume cannot be prevented. The content of the organic acids may range from about 10 to about 80%, preferably from about 20 to about 50%, based on the total weight of the bathing preparation. 
     Adipic acid, which is hardly soluble in water, sometimes show floatation when dissolved in bath water. Therefore, adipic acid may be solubilized by surface-treatment with a water soluble polymer, e.g., sodium polyacrylate or sodium carboxymethyl cellulose, or a hydrophilic nonionic surfactant, e.g., polyethylene glycol, sucrose fatty acid ester or polyglycerol fatty acid ester or a combination thereof. 
     The highly volatile perfume herein means a perfume having a vapor pressure of 1 mmHg or more. Examples of such the highly volatile perfumes that can be used in the bathing preparation of the present invention include terpene hydrocarbons having 10 carbon atoms such as a-pinene, β-pinene, camphene, limonene, terpinolene, myrcene and p-cymene; formates of an alcohol having 5 to 10 carbon atoms such as geranyl formate, benzyl formate and phenylethyl formate; acetates of an alcohol having 5 to 10 carbon atoms such as isoamyl acetate, citronellyl acetate, geranyl acetate, benzyl acetate, linalyl acetate, phenylethyl acetate, menthyl acetate, bornyl acetate, terpenyl acetate, cinnamyl acetate, anisyl acetate and myrcenyl acetate; and propionates of an alcohol having 5 to 10 carbon atoms such as linalyl propionate, citronellyl propionate, geranyl propionate, benzyl propionate, terpenyl propionate and cinnamyl propionate. 
     Such a highly volatile perfume can be employed alone in the bathing preparation of the present invention, or alternately, it may be blended with at least one other perfume. 
     The content of volatile perfumes in the bathing preparation of the present invention can range from about 0.001 to about 2%, preferably from about 0.005 to about 0.6%, based on the total weight of the bathing preparation. The content of the total perfume composition can preferably range from about 0.2 to about 2% based on the total weight of the bathing preparation. 
     In addition to the above-mentioned components, the bathing preparation of the present invention can further comprise, for example, a sulfate, such as sodium sulfate, magnesium sulfate or zinc sulfate and a hydrochloride such as sodium chloride, potassium chloride and magnesium chloride. 
     Furthermore, the bathing preparation of the present invention may comprise commonly employed additives (for example, colorants, vitamins, components contained in hot spring water, proteases, algae extracts, sodium alginates, lanolin, silicones, herbs, herb extracts, etc.) to enhance benefits provided by bathing. 
     When the pH value of bathing water is adjusted to about 5 to about 7, by appropriately selecting the ratio of organic acids and carbonates present in the bathing preparation of the present invention, carbon dioxide gas can be present in the bath water in a dissolved state. The carbon dioxide gas dissolved in the bath water can give an additional effect, e.g., an increase in the blood circulation. 
     The bathing preparation of the present invention may be formulated into various forms in a manner as disclosed, for example, in EP-A 0 333 223. Preferably, the bathing preparation of the present invention is formulated into a tablet which makes it possible to improve the dissolution of carbon dioxide gas in bath water. However, such the bathing preparation can also be formulated into powders or granules. Upon formulation, fillers or lubricants may be further added, if desired. 
     As described above, the bathing preparation of the present invention, which comprises organic acids in which adipic acid amounts to 70% or more, can retain a particular highly volatile perfume within bath water for prolonged periods of time without being vaporized into the air, thus providing beneficial bathing effects. 
     To further illustrate the present invention, the following Examples will be given. Unless otherwise specified, all percents are by weight. 
     Table 1 summarizes perfumes A-K which are used in the following Examples. 
     
                                           TABLE 1__________________________________________________________________________Perfume   A  B  C  D  E  F  G  H  I  J  KComposition     (%)        (%)           (%)              (%)                 (%)                    (%)                       (%)                          (%)                             (%)                                (%)                                   (%)__________________________________________________________________________Limonene  60          40       52 40 70 8Pinene    20                      20Terpinolene     20          10       10       1Geranyl formate        40       20    30    1  1Benzyl formate        30          10Phenylethyl  30       30formateCitronellyl     20          20 2     1  3acetateGeranyl acetate 30                5  1  3Benzyl acetate  10       10 10    1Phenylethyl     20       30    4        1acetateTerpenyl acetate           20                      3Benzyl propionate  40    50          1  2Isoamyl propionate 10       40       2Terpenyl propionate              50Lilial                            10    15Methyl dihydro-                      10 10jasmonateCyclamen aldehyde              1        5Isoamyl salicylate                2Methyl anthranilate            1        1Methyl methyl-                    1     1anthranilateMethyl naphthyl                   1EtherEthyl naphthyl                    1     1EtherTonalide                          4Pentalide                      4        10Galaxolide                     4  1  10 20Ethyl vanillin                   0.1 1Anisaldehyde                            1Geraniol                       5        8Anethole                             2  1Phenyl ethyl                    14.8                             13alcoholTerpineol                         1Damascone                        0.1   0.5Ionone                         1        5Allylamyl                              0.5glycolateCis-3-Hexenyl                           1salicylate__________________________________________________________________________ 
    
     EXAMPLE 1 
     
         ______________________________________Sodium Hydrogen Carbonate               43.8 (%)Sodium Carbonate    15Organic Acids       40(specified in Table 2)Dextrin             0.8Perfume A           0.4______________________________________ 
    
     A bathing preparation of the above composition was mixed and tabletted. Then 50 g of tablet of each bathing preparation was introduced with a bathtub (910×710 mm) filled with 150 l of water at 40° C. The odor of the bath water was organoleptically evaluated three times by ten skilled panelists, at various times intervals, based on the following criteria, and expressed in the major result thereof. 
     Criteria for Evaluation 
     A: Full smell. 
     B: Moderate smell. 
     C: Weak smell. 
     D: No smell. 
     However, it is to be noted here that criteria A and B mean an odor satisfactory as a bathing preparation. 
     Table 2 summarizes the results, wherein Products 1 to 4 are comparative examples and Products 5 to 8 are examples privided occording to the present invention. 
     
                                           TABLE 2__________________________________________________________________________        Comparative  Product of        Product      the Invention        1   2  3  4  5  6  7   8        (%) (%)               (%)                  (%)                     (%)                        (%)                           (%) (%)__________________________________________________________________________Organic Acid CompositionSuccinic Acid        100 80 60 40 30 20 0    0Adipic Acid  0   20 40 60 70 80 100 70Tartaric Acid        0    0  0  0  0  0 0   30Intensity of OdorAt disintegration        C   C  B  A  A  A  A   AAfter 5 minutes        D   C  C  B  A  A  A   BAfter 15 minutes        D   D  C  B  A  A  A   BAfter 60 minutes        D   D  C  C  B  A  A   B__________________________________________________________________________ 
    
     EXAMPLE 2 
     
         ______________________________________Sodium Hydrogencarbonate               41.8 (%)Sodium Carbonate    15.0Organic Acids       40.0(specified in Table 3)Dextrin             0.8Polyethylene Glycol 6000               2.0Perfume A           0.4(specified in Table 3)______________________________________ 
    
     A bathing preparation of the above composition was mixed and tableted. Then each bathing preparation was introduced into a bathtub in the same manner as described in Example 1. The odor of the bath water was organoleptically evaluated by skilled panelists, similar to Example 1. Table 3 shows the results, wherein Product 9 is a comparative example and Products 10 to 15 are of the present invention. 
     In the production of the bathing preparation, the adipic acid had been passed through a sieve of 60 mesh and preliminarily treated by mixing with 0.03% of a sucrose fatty acid ester prior to the use in order to provide increased solubility of the adipic acid in water. 
     
                       TABLE 3______________________________________     Compar-     ative     Product Product of Invention     9       10    11    12   13  14   15______________________________________Perfume     B         B     C   D    E   F    GOrganic acidComposition (%)Succinic acid       90        30    30  30   30  20   20Adipic acid 10        70    70  70   70  80   80Intensity of odor       D         A     B   A    B   A    Aafter 60 minutes______________________________________ 
    
     A bathing preparation of the same composition as the one described in Example 2, except that the perfume specified in Table 4 was used, was mixed and tabletted. Then each bathing preparation was introduced into a bathtub in the same manner as described in Example 1. Similarly to Example 1,  the odor of the bath water was organoleptically evaluated by skilled panelists. Table 4 shows the results wherein Product 16 is a comparative example and Products 17 to 20 are of the present invention. 
     
                       TABLE 4______________________________________      Compara-      tive      Product   Product of the Invention      16        17    18      19  20______________________________________Perfume      H           H     I     J   KOrganic acidComposition (%)Succinic acid        100         30    30    30  30Adipic acid   0          70    70    70  70Intensity of odor        D           B     A     A   Bafter 60 minutes______________________________________ 
    
     While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.