Package For Preparation And Dispensing Of Heated Foam

Abstract

A package adapted for preparing and dispensing heated foam, which comprises a manually openable sealed outer container and a manually rupturable sealed inner container, said package containing A. an aqueous dispersion of a foamable composition, B. hydrogen peroxide, C. a reductant composition, D. an organic propellant selected from A. 1,2-Dichlorohexafluoropropane B. 1,2-Dichloro-1,2,2-trifluoroethane C. Perfluorodimethylcyclobutane D. 1,2-Dichloroperfluorocyclobutane Wherein materials (B) and (C) are isolated from each other in the separate containers of said package.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a package adapted for preparing and dispensing self-heating foam in which heat is generated by a redox reaction and in which a normally liquid propellant is utilized.

2. Description of Prior Art

The field of heated foam packages is predominated by rigid, complex and costly containers and dispensers containing therein foamable compositions, redox reactants and various propellants. Such packages normally provide for separate storage of oxidants and reductants, with one of these reactants combined during storage with the foamable composition. Mechanical valves, passages, tubes and the like provide the means for mixing of oxidant, reductant and foamable composition upon expulsion from the container.

A package has now been invented which allows for the preparation and dispensing of heated foam from noncomplex, nonrigid containers which employ normally liquid propellants.

SUMMARY OF THE INVENTION

The present invention comprises a package having a manually openable sealed outer container and a manually rupturable sealed inner container, said package containing

A. an aqueous dispersion of a foamable composition,

B. hydrogen peroxide

C. a reductant composition which reacts at room temperature with the said hydrogen peroxide to produce heat, said reductant composition being an alkali metal sulfite or a mixture of an alkali metal sulfite and an alkali metal thiosulfate, and

D. an organic propellant for dispensing material (A) selected from

A. 1,2-Dichlorohexafluoropropane

B. 1,2-Dichloro-1,2,2-trifluoroethane

C. Perfluorodimethylcyclobutane

D. 1,2-Dichloroperfluorocyclobutane wherein materials (B) and (C) are isolated from each other in the separate containers of said package.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a package of this invention.

FIG. 2 is a cross section of the package of FIG. 1 along the lines 2--2.

CDESCRIPTION OF THE INVENTION

It is now been discovered that heated foams can be prepared and dispensed from noncomplex, nonrigid containers employing therein a normally liquid propellant heated to a temperature above its boiling point by redox reaction. The complexity and cost of the prior art containers comprises rigid walls, mechanical valves, passages, etc., are thus avoided.

The package of this invention in its preferred embodiment, as shown in FIGS. 1 and 2, intended for single use, comprises a manually openable outer container 1 prepared from a plastic or plastic laminated on its outside to metal foil which container is sealed 5 and contains a foamable material and a reductant or reductants 2 selected from an alkali metal sulfite alone or in a mixture with an alkali material thiosulfate. Within this outer container is a smaller manually rupturable inner container 3 which is sealed 6 and contains hydrogen peroxide 4 in an amount chemically equivalent to or preferably slightly less than equivalent to the amount of reductant contained in the mixture with the foamable material. The hydrogen peroxide may be optionally thickened as described in the examples. Thickened hydrogen peroxide, while producing more stable foams, is however more difficult to mix. Other embodiments are of course possible, e.g., the containers could be prepared from flexible molded plastic provided that the inner container is still rupturable.

It is readily apparent also that the order of storage of the reactants may be reversed, that is, the hydrogen peroxide may be contained in the outer container and the other materials in the inner container. Further, as taught by Seglin et al., in French Pat. No. 1,468,909, the hydrogen peroxide may be stored in mixture with selected soaps which do not decompose the hydrogen peroxide. The reductants are, of course, stored in a container separate from the hydrogen peroxide container within the package thus isolating the two reactants from each other while in storage.

It will occur to one skilled in the art that various materials can be used to prepare the containers of the package of this invention. A primary consideration, however, is that the material of the hydrogen peroxide containing container not catalytically decompose hydrogen peroxide, nor should the hydrogen peroxide attack or rapidly permeate the container material. The material of construction of the nonhydrogen peroxide containing container is less critical. Polyethylene, for example, is a suitable material and if the nonhydrogen peroxide containing container is the outer container, polyethylene laminated to a stronger film such as polyethylene terephthalate may be used.

In utilizing one embodiment of this invention, the inner sealed container is first ruptured manually, e.g., by the application of pressure between the fingers; the package is then shaken to allow the reactants to contact one another thus effecting the heat generating redox reaction; the outer sealed container is then manually opened, e.g., by puncturing or tearing off a corner, and the heated foam extrudes from the package through the opening thus created.

The term "aqueous dispersion of a foamable composition" referred to herein means an aqueous solution or dispersion of a foam-producing agent capable of forming a foam when dispensed from the package of this invention. There are no special limitations on the nature of the foamable composition except that it should not contain any materials which would interfere with the redox reaction, e.g., it should not contain oxidants which would oxidize the sulfite or thiosulfate reductant dissolved therein. Strongly acid materials which would alter the reductants are also undesirable. Strongly alkaline materials can, however, be utilized for they do in fact accelerate the redox reaction. These strongly alkaline materials may be particularly effective when utilized as oven cleaners and the like. Materials which strongly catalyze the decomposition of hydrogen peroxide, such as those described in Seglin et al., French Pat. No. 1,468,909, are avoided because the heat produced by hydrogen peroxide decomposition is less than that produced by redox reaction on an equal weight basis. The best type and concentration of foam-producing agent in the composition for a particular application can be readily determined by one skilled in the art and is not critical for purposes of this invention; however, the composition usually contains about 30 to 35 percent by weight of foam-producing agent. Useful foam-producing agents are exemplified by the soluble anionic soaps, for example the potassium, ammonium and soluble amine soaps of stearic acid, as well as vegetable oils soaps, various synthetic materials known as wetting agents or surfactants and fibrous alumina monohydrate in combination with a foam coactive. The foamable composition should be nongelling at room temperature, and contain additives known in the art such as glycerine, light mineral oil, perfume, antifreeze agents, silicon fluids, viscosity controlling agents and the like. Products to be applied to the body, such as shaving lathers, hair conditioners, etc., must, of course, contain only physiologically acceptable materials and the pH must be near 7.

The reductants of this invention react with hydrogen peroxide at room temperature, e.g., alkali metal sulfites or a mixture of an alkali metal sulfite and alkali metal thiosulfate. The preferred reductants are potassium sulfite and a mixture of potassium sulfite and potassium thiosulfate because there is less likelihood that the potassium salts will gel soap solutions. In the case of a mixture of the sulfite and thiosulfate salts, the mol ratio of potassium thiosulfate to potassium sulfite is not critical; however, for best results the ratio should be from about 3 to 5 to about 2 to 3, respectively. Furthermore, for best results, the amount of reductant mixture present in admixture with the aqueous dispersion of a foamable composition, if in fact they are admixed, while not critical, usually ranges from about 6 to 10 percent by weight. When the reductant utilized is potassium sulfite salt alone and it is admixed with the aqueous dispersion of a foamable composition, the amount of said reductant in admixture is usually from about 6 to 10 percent.

Several physical properties appear to affect the suitability of a normally liquid propellant for use in this invention. The most important of these properties appears to be the boiling point of the propellant, and the choice of propellant based on boiling point properties is affected by the temperature at which the package is to be heated. In the system of this invention, this temperature is fixed by the amounts of oxidant and reductant, the choice of reductant, the heat capacity of the materials of package construction, the heat loss from the package and the latent heat of vaporization of the propellant. A comfortable temperature for application of foam to the human skin is from about 120.degree. to about 150.degree. F.

The overall stability of the heated foams produced appears to be related to less clearly defined physical properties such as the ability of the propellant to disperse in the foamable composition. The stability of the foam appears to be related not only to its composition as known in the art but also to the permeation rate of the propellant through the cell walls, condensation of the propellant within the cells upon cooling of the foam, etc.

It has been found that chlorofluorocarbons and perfluorocarbons having boiling points of from about 80.degree. to about 115.degree. F. are suitable propellants for use in this invention. While propellants having boiling points above this range, i.e., to about 140.degree. F., are sometimes operable. The range described above is preferred and the most preferred boiling point is about 95.degree. F. The following normally liquid propellants, arranged in the order of decreasing preference, are effective when utilized in the present invention.

Boiling Point Propellant .degree. F. __________________________________________________________________________ 1,2-dichlorohexafluoropropane 94.1 1,2-dichloro-1,2,2-trifluoroethane 82.8 Perfluorodimethylcyclobutane 114.0 (mixed isomers) 1,2-dichloroperfluorocyclobutane 139.8 __________________________________________________________________________

About 12 to 18 percent of propellant is usually used based on the combined weight of propellant and foamable composition. The amount of propellant utilized may, however, be greater depending upon the containers used.

EXAMPLES

The following examples are intended to be merely illustrative of the invention and not in limitation thereof. Unless otherwise indicated, all quantities are on a weight basis. The composition of foamable materials used in the following examples is not critical to the operability of the invention; for other formulations, known in the art, are operable. Utilizing these foamable materials, three soap formulations were prepared each in three parts designated A, B, and C below. Percent values are based on the total soap formulation comprising all three parts in combination. --------------------------------------------------------------------------- PART A

formu- Formu- Formu- lation 1 lation 2 lation 3 wt. % wt. % wt. % Acetylated lanolin.sup.1 0.8 0.8 0.8 Cetyl alcohol 0.5 0.5 0.5 Sorbitol monostearate.sup.2 0.5 0.5 0.5 Mineral oil 0.5 0.5 0.5 Polyoxyethylene sorbitan 4.5 4.5 4.5 monostearate.sup.3 __________________________________________________________________________ --------------------------------------------------------------------------- PART B

formu- Formu- Formu- lation 1 lation 2 lation 3 wt. % wt. % wt. % Coconut fatty acid 1.0 1.0 Stearic acid 9.0 7.0 7.0 Stearyl Alcohol 1.0 Lauric Acid 1.0 __________________________________________________________________________ --------------------------------------------------------------------------- PART C

formu- Formu- Formu- lation 1 lation 2 lation 3 wt. % wt. % wt. % Deionized Water 66.1 69.1 68.1 Triethanolamine 3.5 3.5 3.5 Potassium Hydroxide 1.2 1.2 1.2 Potassium Sulfite .sup.. 2H.sub.2 O 5.0 5.0 9.0 Potassium Thiosulfate 3.0 3.0 Sorbitol, 70 wt. % in Water.sup.4 3.0 3.0 3.0 Perfume 0.4 0.4 0.4 __________________________________________________________________________

The hydrogen peroxide solutions were prepared by dilution with deionized water of commercial concentrated hydrogen peroxide containing conventional inhibitors. The thickened hydrogen peroxide formulations containing 13 wt. percent hydrogen peroxide were prepared as follows:

Ingredient Wt. % Hydrogen peroxide, 35 wt. % 37.0 Cetyl alcohol 2.5 Glycerol monostearate 2.5 Deionized water 58.0

The deionized water at 70.degree. C. was slowly stirred into a 70.degree. C. melted mixture of cetyl alcohol and glycerol monostearate. The mixture was allowed to cool while stirring whereupon 35 percent hydrogen peroxide was added with stirring until blended. Deionized water was then added to make up evaporation losses.

The outer container used in the examples consisted of two approximately 31/2.times. 4 in. sheets of 10 mil thick polyethylene laminated on the outside to aluminum foil. The inner container, containing hydrogen peroxide, consisted of two pieces of approximately 1 mil thick polyethylene sheet about 1 in. square.

EXAMPLE 1

In the runs reported in Table 1 of this example, the hydrogen peroxide was charged to the inner container which was then heat sealed and placed inside the outer container. The soap formulations and propellant were added to the outer container which was then also heat sealed. In these runs, the sealed containers were first shaken vigorously, the inner container was then ruptured and the contents of both envelopes were mixed by kneading for about 30 seconds whereupon a corner of the outer container was torn off. The warm foam was expressed into a beaker where its temperature was measured by a small thermometer in the center of the foam.

The results of the 12 runs are shown in Table 1 below. ##SPC1##

Since heated foams are needed for various applications, all those formulations above which produced foams of some stability are regarded as operable. Propellants which in at least one formulation produced foams of some stability are therefore also regarded as operable.

It should be noted that when 1,1,2-trichloro-1,2,2-trifluoroethane was utilized as the propellant in Run No. V, the results were unsatisfactory; and yet when 1,2-dichlorohexafluoropropane of this invention was utilized as the propellant with the same formulation (Run No. IV), the results were quite satisfactory.

For shave lather the components of runs IV and XII are preferred.

EXAMPLE 2

In another embodiment of this invention, a redox reaction of hydrogen peroxide and sodium sulfite was carried out separately in an intermediate container, the heat of reaction therefrom being transferred through the wall of the intermediate container to warm the soap solution contained in the outermost container.

The package therefore consisted of three containers, one inside the other. The innermost polyethylene container, approximately 1 inch square, contained 0.4 cc. of 30 weight percent H.sub.2 O.sub.2 and 2.6 cc. water and was heat sealed at the edges. The intermediate container, about 2.times. 3 inches in size and consisting of 4 mil polyethylene, contained 0.4 grams sodium sulfite and was sealed at the edges. The outer container containing 5 cc. of an approximately 24 percent aqueous solution of commercial lather shave cream and 2 cc. 1,2-dichloro-1,2,2-trifluoroethane, consisted of a 2 mil thick, 1 qt. capacity polyethylene bag heat sealed at all edges. Air was excluded from all envelopes before heat sealing.

The innermost container was ruptured and its contents were mixed with the sodium sulfite of the intermediate container by kneading. The package was then shaken and warmed foam was expressed from the outermost container, through an opening which was made therein, into a graduated funnel. Approximately 80 cc. of foam was realized which was stable for more than 20 minutes.

The novel package of this invention has a variety of applications where it is desired to prepare and dispense warm aqueous foam. The invention is especially useful for preparing warm aqueous foams for such applications as conditioning areas of a person to be shaved, and washing the skin or hair. Such utility is particularly beneficial to campers, yachtsmen and others who often do not have access to hot water. This novel package is adapted for preparing warm foam quickly, efficiently and without a need for a source of electricity, steam, or hot water.

Although the chemical components of this invention have been described in the examples in terms of potassium and sodium salts, it is evident that any alkali metal sulfite or a mixture of any alkali metal sulfite and thiosulfate would be operable. It is further understood that as many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, the invention is not limited to the specific embodiments thereof.

Claims

What we claim is:

1. A package adapted for preparing and dispensing heated foam, which comprises a manually openable sealed outer container and a manually rupturable sealed inner container, said package containing

A. an aqueous dispersion of a foamable composition selected from the group consisting of soluble anionic soaps,

B. hydrogen peroxide,

C. a reductant composition which reacts at room temperature with the said hydrogen peroxide to produce heat, said reductant composition being an alkali metal sulfite or a mixture of an alkali metal sulfite and an alkali metal thiosulfate, and

D. an organic propellant for dispensing material (A) selected from the group consisting of

a. 1,2-Dichlorohexafluoropropane and

b. 1,2-Dichloro-1,2,2-trifluoroethane wherein materials (B) and (C) are isolated from each other in the separate containers of said package.

2. A package according to claim 1 wherein the organic propellant (D) is 1,2-dichlorohexafluoropropane.

3. A package according to claim 1 wherein the organic propellant (D) is 1,2-dichloro-1,2,2-trifluoroethane.

4. A package according to claim 1 wherein the outer container is prepared from polyethylene laminated on the outside to aluminum foil.

5. A package according to claim 1 wherein the inner container is prepared from polyethylene.