US3370014A - Skin cleansing compositions - Google Patents

Description

United States atent tice 3,370,014 SKIN CLEANSING COMPUSITIONS Irving Reich, Princeton, and Hans Breuer, Somerville,

N.J., assignors to Carter-Wallace, Inc., a corporation of Maryland No Drawing. Continuation of application Ser. No.

291,277, June 28, 1963. This application Oct. 20,

1965, Ser. No. 499,097

2 Claims. (Cl. 252-90) ABSTRACT OF THE DISCLGSURE A pressurized aerosol package for producing a coherent foam which breaks down on rubbing, containing a liquid soap solution consisting essentially of triethanolamine stearate (3%), refined mineral oil (-20%) and water, and a liquefied normally-gaseous propellant consisting of dichlorodifluoromethane (85 parts) and monochlorodifluoromethane parts).

This application is a continuation of US. Serial No. 291,277, filed June 28, 1963 and now abandoned.

The present invention relates to skin cleansing compositions. Mor particularly, the present invention relates to pressurized skin cleansing compositions suitable for use on the most sensitive skin areas of infants.

A number of cleansing preparations have been used in the past to simplify the rather unpleasant task of cleansing the delicate diaper areas of infants. While a search for a preparation which is effective, sanitary, non-irritating and convenient to use has resulted in a number of commercial cleansing compositions which have greatly simplified such task, heretofore no single composition has been able to fulfill all the desired requirements. For example, while the commercial baby soaps are ffective in the rapid removal of feces from the skin of the infant, the use of such soaps is inconvenient since water and a wash cloth must be used in connection therewith. Furthermore, since the use of such soaps results in the excessive removal of natural skin oils, it is usually desirable to replace such oils by applying a baby oil or a baby lotion to the cleansed areas. Such additional step adds further to the inconvenience created by the use of soap.

The use of commercial baby oils and baby lotions as sole cleansing agents leaves much to be desired since such agents are not completely effective in removing dirt rapidly. For complete dirt removal, the skin of the infant must be subjected to prolonged rubbing which in many cases may result in irritation of the delicate membranes of the perianal area or may aggravate any existing diaper rash. Furthermore, the liquid oils and lotions tend to run and drip when applied to the area to be cleansed, resulting in further inconvenience to the user. Another inconvenience associated with the use of such liquid cleansers is the danger of spillage which exists while the liquid is being applied and up to the time the closure is replaced on the liquid container.

Such latter inconvenience can be theoretically easily overcome by providing a liquid skin cleansing composition in a pressurized container. However, previous attempts to produce an acceptable pressurized skin-cleansing composition have proven unsuccessful in practice since, in general, skin-cleansing compositions dispensed in the form of stable foams are not sufiiciently liquid and do not produce a good cleansing action while spray-type skin cleansers tend to run and drip when applied to the skin.

It is an object of the present invention to provide a skin-cleansing composition which is suitable for packaging in a pressure container and which will not possess any of the disadvantages hereinbefore described. It is another object of the invention to provide a pressurized skincleansing composition which will form a coherent foam upon release from the container, said foam breaking down to form a cleansing oil-in-water emulsion upon rubbing. It is a further object of the invention to provide effective, sanitary non-irritating and convenient means for cleansing the diaper areas of infants. It is a still further object of the invention to provide a mild skin-cleansing foam especially suitated for cleansing the most sensitive areas of infants skin without irritation thereto. It is a still further object of the invention to provide a mild skin-cleansing foam having antifungal and antibacterial activity. These and other objects will become apparent to thoscs killed in the art in the light of the instant specification.

In a broad aspect, the present invention is directed to a skin-cleansing composition suitable for packaging in a pressure container and for forming a coherent foam upon release from said container, said foam breaking down to form a cleansing oil-in-water emulsion upon rubbing, said composition consisting essentially of a liquid mixture of an aqueous soap solution and of a normallygaseous propellant, said soap solution comprising from about 1 to about 4 percent by weight of triethanolamine stearate and from about 8 to about 25 percent of a refined mineral oil having a viscosity in the range of from to 355 seconds Saybolt at F. When packaged in a pressurized container, the novel compositions of the present invention provide sanitary and convenient means for cleasing the skin of infants. When released from the pressurized container, the novel compositions form a coherent foam which, when rubbed on the infants skin, breaks down to form an oil-in-water emulsion which possesses good cleansing properties and which is extremely mild to even the most sensitive portions of the skin. Furthermore, the novel compositions are compatible with a number of additives which can be used to enhance the properties of said compositions and which will be described in detail hereinafter.

The triethanolamine stearate used in the present invention is the triethanolamine soap of commercial stearic acid. The product sold commercially as stearic acid is actually a mixture consisting primarily of stearic and palmitic acids. Therefore, as used herein and in appended claims, the term triethanolamine stearate is used .to designate the triethanolamine soap of commercial stearic acid although the triethanolamine soap of chemically pure stearic acid would be equivalent for the purpose of the invention.

Triethanolamine stearate, which is produced by neutralizing stearic acid with triethanolamine, is a commercial item and can be introduced into the compositions of the present invention in its neutral form. It is preferred, however, for reasons which will become apparent hereinafter, to prepare our triethanolamine stearate in situ by adding to the aqueous solvent medium appropriate amounts of stearic acid and triethanolamine.

The amounts of triethanolamine stearate used in the compositions of the present invention range from about 1 to about 4 weight percent, based on the weight of the aqueous soap solution. An amount of about 3 weight percent is preferred.

As stated above, the refined mineral oil is used in the compositions of the invention in an amount of from about 8 to about 25 percent, based on the weight of the aqueous soap solution. An amount in the range of from about 10 to about 20 weight percent is preferred. While a refined mineral oil having a viscosity of from 70 to 355 seconds Saybolt at 100 F. is suitable for use in the practice of the present invention, a refined mineral oil having a viscosity in the range of from 75 to 100 seconds Saybolt at 100 F. is preferred.

While not essential to the practice of the invention, it is preferred to add to the novel compositions small quantities of free stearic acid and of a non-ionic foam stabilizer. Such additives have been found to enhance the texture, stability and feel of the foam without adversely affecting its cleansing power or its tendency to break down to form an oily liquid film on rubbing.

The stearic acid used is normally a commercial stearic acid as hereinbefore defined. Such free stearic acid is advantageously introduced into the novel compositions of the invention by using an appropriate molar excess of stearic acid in the in situ preparation of the triethanolamine stearate. Alternatively, if the triethanolamine steara'te is not produced in situ, the free stearic acid can be added to the compositions as a separate component. Preferred amounts of free stearic acid are in the range of from about 0.1 to about 1.0 weight percent, based on the weight of the aqueous soap solution. In addition to improving the texture, feel and stability of the foam, such free stearic acid enhances the mildness of the novel compositions and insures that no irritation will occur if the product is not completely removed from the infants skin.

When one or more non-ionic foam stabilizers are used in the novel composition, such stabilizers can be used in a total amount of up to weight percent, or higher, based on the weight of the aqueous soap solution. Although a number of non-ionic foam stabilizers are generally operable in the practice of the present invention, the preferred stabilizer is a lauric acid-diethanolamine condensation product sold under the trademark Super Amide L-9. Super Amide L9 is a condensation product of commercial lauric acid and diethanolamine which contains at least 90 percent of diethanolamide and only minor amounts of free diethanolamine and condensation byproducts. Such preferred stabilizer can be used as the sole foam stabilizer or in combination with other non-ionic foam stabilizers such as, for example, a polyoxyethylene stearate which contains an average of 8 oxyethylene radicals per molecule and which is sold under the trade name Myrj 45. From the point of view of economics and foam stability, it is particularly preferred to use the lauric acid-diethanolamine condensation product as the sole non-ionic foam stabilizer in an amount of from about 0.1 to about 1.0 weight percent, based on the weight of the aqueous soap solution.

A number of additional ingredients which are compatible with the compositions of the present invention can be added thereto to enhance the skin-cleansing effectiveness of the foams produced therefrom. Among such ingredients there may be mentioned, for example, germicidal agents, healing agents and skin softening agents.

Preferred germicidal agents include, for example, hexachlorophene, para-chloro-meta-xylenol, S-hydroxyquinoline, hexylresoricinol, ortho-phenyl-phenol, 2,2'-thiobis-4, 6-dichloropheno1, and mixtures of polybrominated salicylanilides. The latter are exemplified by products sold under the trade names of ACS 4 Diaphene and Temasept. Preferably two or more of the above germicidal agents are used in combination in effective amounts as to impart both antibacterial and antifungal properties to the compositions of the invention. A particularly preferred combination which renders such compositions effective against both gram-positive and gram-negative bacteria as well as against pathogenic fungi such as Trichophyton rubrum, T richophyton mentagrophytes, and Candida albicans is hexachlorophene and para-chloro-meta-xylenol.

As healing agent, it is preferred to add to the compositions of the invention a minor amount of cod liver oil. Such cod liver oil, in addition to aiding in the healing of minor bruises and skin blemishes, also acts as a skin-softening agent. When cod liver oil is used in the skin-cleansing compositions of the invention it is desirable that such compositions also contain an antioxdant, such as 2,6-ditertiary-butyl-para-cresol, in an amount sufiicient to inhibit rancidity in the cod liver oil. Alternatively, a stabilized cod liver oil, i.e., a cod liver oil which already contains rancidity inhibitors, can be used.

The normally-gaseous propellants of the present invention should be substantially non-toxic and odorless and can be either relatively water-insoluble compounds which, under the conditions prevailing in the pressurized con tainer, exist in the liquefied state and in dispersion in the aqueous solvent medium, or substantially water-s-oluble inert inorganic gases. 7

Suitable liquefied propellants include the relatively water-insoluble saturated hydrocarbons and relatively water-insoluble partially or wholly chlorofluor'inated hydrocarbons having vapor pressures in the range of from about 5 to about 300 pounds per square inch gauge at 70 C. The propellant may also be formed of a mixture of two or more such compounds. Suitable propellants in clude, for example, propane, isobutane, monochlorodifltioromethane, monofluorotrichloromethane, dichlorodifluoromethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, trichlorotrifluoroeth-ane, monochloropentafluoroethane, and the like.

The substantially water-soluble inert inorganic gases which form an additional class of propellants which can be used in the practice of the present invention can be exemplified by nitrous oxide, carbon dioxide and mixtures thereof. Upon introduction into the pressure container, such gases become dissolved into the aqueous medium. When the pressurized composition is relased from the container, the dissolved gas bubbles out of solution, causing the formation of a coherent foam which breaks down to form an oil-in-water cleansing emulsion upon rubbing.

The amount of propellant in the pressurized composi tions is not critical. In general, the propellant need only be present in an amount to satisfactorily propel the aqueous soap composition from the pressurized container in the form of a coherent foam. The type and amount of propellant should preferably be selected as to obtain a pressure of from about 20 to about pounds per square inch gauge at F. in the pressurized container and a density in the range of from about 0.06 to about 0.12 grams per cubic centimeter for the extruded foam. Pressures in the range of from about 30 to about 50 pounds per square inch gauge are preferred from a practical standpoint since they permit complete removal of all the dispensable material from the pressurized container while at the same time, allow the use of the standard pressure containers which are used at present for commercial pressurized products.

While all the above-mentioned propellants are suitable for use in the practice of the present invention, it has been found that, in general, the foams produced from compositions pressurized by using such propellants tend to emerge from the pressurized container in the form of a soft wet lather prior to expanding rather slowly to coherent foams of the desired stability. While such feature is not detrimental to the effectiveness of the foams, it is preferred, from an aesthetic and marketing point of view, that the novel compositions emerge from the pressurized container as fully developed coherent foams. It has unexpectedly been found that 'such desirable results can be obtained by using a preferred propellant composition consisting of about parts by weight of dichlorodifiuoromethane and about 15 parts by weight of monochlorodifluoromethane. When the compositions of the invention are pressurized to the aforementioned pressures by means of the above propellant compositions, the foams produced therefrom emerge from the pressurized container as a fully developed coherent lather of the desired stability. Such result is totally unobvious to one skilled in the art since if monochloropentafluoroethane, which has substantially the same vapor pressure curve as monochlorodifluoromethane, is substituted therefor in the preferred propellant compositions, foams obtained under identical conditions are soft and wet prior to expanding rather slowly to coherent foams of the desired consistency. Therefore, in the practice of the present invention, the preferred propellant consists of a mixture consisting of about 85 parts by weight of dichlorodifluoromethane and of about 15 parts by weight of monochlorodifluoromethane.

The pressurized compositions of the invention can be prepared in any suitable manner. One satisfactory method comprised admixing the triethanolamine stearate, the mineral oil and any other desired additives with Water and adding the resulting mixture to a pressure container which is subsequently sealed. Thereafter the propellant composition can be admitted under pressure through a valve or other appropriate means.

In order to illustrate more fully the nature of the present invention the following specific examples are set forth. It is to be understood that these examples are presented to illustrate some preferred embodiments of the present invention and are not intended to limit the scope thereof in any manner.

Example 1 A mixture was formed by admixing and heating the following ingredients:

Wt. percent Stearie acid (commercial) 2.45 Triethanolamine 1.05

Refined mineral oil (80-90 seconds Saybolt at Containing 2 weight percent of 2,6-ditertiarybuty1paracresol as rancidity inhibitor.

It is calculated that 1.95 parts of the stearic acid are neutralized by the triethanolamine. Therefore the final mixture contains 3.00 parts of triethanolamine stearate and 0.50 part of free stearic acid.

A suitable amount of the above mixture was added to a pressure container and the container was sealed by means of a manually-operated discharge valve. To the sealed container there was added through the valve a propellant mixture consisting of about 85 parts by weight of dichlorodifluoromethane and about 15 parts by weight of monochlorodifluoromethane. The internal pressure of the pressurized container was measured to be about 50 pounds per square inch gauge at 70 F. Upon operation of discharge valve, the contents emerged from the container as a fully developed coherent foam, having a lather density of 0.083 to 0.093 g./cc. Such foams broke down readily on rubbing, forming a liquid oil-in-water emulsion having excellent skin-cleansing properties.

Examples 2-5 Four aqueous soap mixtures, having the composition hereinafter set forth, were prepared.

Weight Percent Ex. 2 Ex. 3 Ex. 4 Ex. 5

Triethanolamine stearate 4. 4. 0 3. 2 3. 2 Refined mineral oil (80-90 seconds Saybolt at 100 F.) 20. 0 10. 0 20. 0 15.0 Free stearic acid 1. 0 0. Laurie acid-diethanolamine condense tion product 2. 0 0. 3 3. 0 0. 4 Polyethylene oxide stearate (Myrj 45) 2.0 0.2 0. 4 Cod liver oil 0. 5 2,6-Ditertiarybutyl-para-eresol 0. 01 Perfume q.s. q.s. q.s. q.s. Water (deionized) 1 Balance.

Each mixture was processed as in Example 1. In each case, the contents emerged from the pressurized container as a fully developed coherent foam, having a lather density in the range of from about 0.075 to about 0.095 g./cc. Such foams broke down on rubbing and the resulting oil-in-water emulsion had good cleansing properties.

As indicated in the preceding examples, the addition of various materials to the novel skin-cleansing compositions is contemplated by the present invention. Thus, in addition to the materials specifically discussed, the finished compositions will contain a perfume which should be selected as to be compatible with the character of the finished product. Furthermore, coloring materials or the like may be used if desired.

What is claimed is:

1. A package comprising a pressure container having a valve-controlled opening and containing skin-cleansing composition suitable for packaging in a pressure container and for forming a coherent foam upon release from said container, said foam breaking down to form an oil-in-water cleansing emulsion upon rubbing, said composition consisting essentially of a liquid mixture of an aqueous soap solution and of a liquefied normally-gaseous propellant, said soap solution comprising about 3 percent by weight of triethanolamine stearate and from about 10 to about 20 percent by weight of a refined mineral oil having a viscosity in the range of from to 100 seconds Saybolt at 100 F., the balance of said solution consisting essentially of water, and said liquefied normally-gaseous propellant consisting of about parts by weight of dichlorodifluoromethane and of about 15 parts by weight of monochlorodifluoromethane.

2. A package comprising a pressure container having a valve-controlled opening and containing skin-cleansing composition suitable for packaging in a pressure container and for forming a coherent foam upon release from said container, said foam breaking down to form an oilin-water cleansing emulsion upon rubbing, said composition consisting essentially of a liquid mixture of an aqueous soap solution and of a liquefied normally-gaseous propellant, said soap solution comprising about 3 percent by weight of triethanolamine stearate, from about 10 to 20 percent by weight of a refined mineral oil having a viscosity in the range of from about 75 to about 100 seconds Saybolt at 100 F., from about 0.1 to about 1 percent by weight of free stearic acid, and from about 0.1 to about 1 percent by weight of a-lauric acid-diethanolamine condensation product, the balance of said solution consisting essentially of water, and said liquefied normallygaseous propellant consisting of about 85 parts by weight of dichlorodiiluoromethane and of about 15 parts by weight of monochlorodifluoromethane.

References Cited UNITED STATES PATENTS 2,524,590 10/ 1950 Boe 252--305 2,655,480 10/ 1953 Spitzer et al. 252- 2,698,301 12/1954 Shumard 252l07 3,079,299 2/ 1963 Heilig 252305 FOREIGN PATENTS 838,913 6/1960 Great Britain.

OTHER REFERENCES Gump et al., Soap and Sanitary Chemicals, December 1952, pages 52-53, 113, 114.

LEON D. ROSDOL, Primary Examiner.

W. SCHULZ, Assistant Examiner.