GB2429055A

GB2429055A - A self heating dispensing device

Info

Publication number: GB2429055A
Application number: GB0516254A
Authority: GB
Inventors: Marcus Allen Bentley; Heidi Fuentes
Original assignee: Reckitt Benckiser LLC
Current assignee: Reckitt Benckiser LLC
Priority date: 2005-08-08
Filing date: 2005-08-08
Publication date: 2007-02-14
Also published as: GB0516254D0

Abstract

A self heating dispensing device 10 comprises a first part 14 and a second part 18 of a thermic module that are mixed together to heat and fluidise a viscous depilatory composition 20 contained in a container 16. The first part 14 and second part 18 may be separated by a membrane/housing 28 that is pierced by at least one thorn 22. First part 14 is a heat transfer medium and may be water or water containing one or more organic solvents that upon mixing with the second part 18, which may be one or more of solid materials such as calcium oxide, calcium chloride and hydrochloric acid, sodium hydroxide, anhydrous copper sulphate, and sulphuric acid to cause an exothermic reaction. Container 16 may be a disposable insert module (70, 80, figs 4 and 5), second part can 18 be removable and replaceable to permit reuse of the device. The depilatory composition may be dispensed via an applicator tool such as a stick, brush or wand or via a roller (fig 2). Vents (62, fig 6) may be provided to release steam that may be produced from the exothermic reaction and a thermochromic indicator that changes colour may be provided to indicate the temperature of the composition.

Description

IMPROVEMENTS IN DEVICES

The present invention relates to a reusable self- heating dispenser for supplying a viscous thixotropic composition useful in the removal of unwanted hair from the body, particularly wherein the thixotropic composition which fluidifies upon heating.

Non-reusable, self-heating containers such as those used in the food and beverage industry, are commonly powered by an exothermic reaction wherein two or more separately housed constituents are mixed within a container : * which initiates an exothermic reaction which is used to heat the food or beverage. Typically the two or more constituents are combined by breaching a membrane or other barrier between compartments separately housing the constituents. The separate constituents materials have no exothermic effect when housed separately until they are mixed which provides for a useful shelf life for the self- heating container.

U.S. Patents 5,461,867 and 5,626,022 are representative of this type of container design. An outer compartment contains the contents to be heated and an inner compartment contains two constituents which when mixed provide an exothermic reaction, here calcium chloride and water, which constituents separated by a pierceable membrane. Once the membrane has been pierced, the calcium chloride and water react exothermically, which evolves heat which is transmitted to the outer compartment and the contents contained therein. Once the exothermic reaction ceases and/or the contents of the outer compartment are dispensed or consumed, the entire container is typically disposed of by a consumer.

While useful, such containers are not without shortcomings. Such prior art containers such as those described above are usually specifically designed for heating food and/or beverages which are often highly aqueous in content; viz., beverages are typically fluids at room temperature or above, and foods used in such prior art containers are often supplied in sauces or gravies which contain a significant proportion. The presence of significant amounts of water in such foods and beverages S...

are beneficial with the use of such prior art self-heating containers as the water in the foods and beverages acts as a rapidly reacting heat transfer fluid which is easily heated by the exothermic reaction. The water in such foods and beverages are thus usually satisfactorily heated by such prior art containers. However the use of such prior : art self-heating containers are not readily adapted to heating of other materials, particularly non-food or non- beverage materials which do not have a high proportion of water.

A further disadvantage of such prior art containers resides in the fact that they are intended to be single-use devices. Namely, once the exothermic reaction is initiated and the food or beverage is either dispensed from the container or consumed from the container, the selfheating container is discarded. No provision is provided for readily reusing the self-heating container for a repeated heating operation.

Known to the cosmetics and personal care art are depilatory compositions, including viscous depilatory compositions which are particularly effective in the removal of unwanted body hair. Often, such viscous depilatory compositions include one or more constituents which need to be effectively fluidified prior to the application of the product to the skin. Such viscous depilatory compositions typically often comprise a wax. In order to effectively fluidify a viscous depilatory composition a consumer is usually directed to sufficiently : *. 15 heat the composition in a container. Currently, techniques S...

for heating such viscous depilatory compositions are by S...

either: partial or total immersion of the container in a water bath, or, heating the container in a microwave oven.

Neither of these techniques is entirely satisfactory. The immersion technique is popularly used as it is unlikely to overheat the viscous depilatory composition however, the .: technique is inconsistently practiced by a consumer which may insufficiently heat the container and thus diminish the likelihood of a satisfactory and uniform application onto the skin. Alternately overheating of the container containing the viscous depilatory composition presents the risk of burning of the skin, discomfort to the user, and inappropriate application onto the skin due as the viscous depilatory composition is too thin and runny to be properly applied. Similarly the use of a microwave oven is even more problematic as great care must be taken to ensure that the viscous depilatory composition is not overheated. This is not always easy as microwave ovens have a tendency to cause localized hot spots in the material being heated.

Furthermore, the power output and efficiency of microwave ovens can vary significantly from one to another. Again, as noted above, insufficient heating of the viscous depilatory composition, or overheating of the viscous depilatory composition often leads to improper application onto the skin, and poor depilation as well. Further, both of these techniques require that a water bath or a microwave be available to a consumer when preparing the viscous depilatory composition for use.

Accordingly, there is a real and evident need in the *.S.

art for improved containers and devices which are useful in the preheating of viscous depilatory compositions prior to their use for the removal of unwanted hair. There is also a need for improved techniques for preheating of viscous depilatory compositions prior to their use for the removal of unwanted hair. It is to these and other needs that the . .: present invention is directed.

In a first aspect, the present invention provides an improved device which are useful in the preheating of a viscous depilatory composition prior to their use for the removal of unwanted hair from skin. Such a device may be a single-use device, or may be a refillable device which can be used for a plurality of times for preheating of viscous depilatory composition.

In a second aspect, the present invention provides an improved dispensing device useful for both preheating a viscous depilatory composition prior to their use for the removal of unwanted hair from skin, and for directly applying the preheated viscous depilatory composition to skin particularly in the locus of unwanted hair growing from the skin. The improved dispensing device may be a single-use device, or may be a refillable device which can be used a plurality of times for preheating of viscous depilatory composition and subsequent application of the preheated composition to skin.

According to a third aspect of the invention there is provided an device according to either the first or second inventive aspects which device includes a body which : * 15 includes a first part of a thermic module and an insert *s..

module comprising a container which contains a non- fluidified viscous depilatory composition and a second part of a thermic module, wherein the insert module is adapted * to be inserted within the body and assembled to form a device according to the first or second aspects of the *s: invention. Once assembled to form such a device, or during assembly of the device, first part of the thermic module and the second part of the thermic module interact to provide an exothermic reaction and thereby heat and fluidify the viscous depilatory composition within the assembled device.

According to a fourth aspect of the invention there is provided improved techniques for preheating of viscous depilatory compositions prior to their use for the removal of unwanted hair which contemplate the use of a device according to any of the first, second or third inventive aspects described herein.

These aspects of the invention and still further aspects of the invention will become more apparent from the

following specification and drawings.

Figure 1 depicts an improved device comprising a body and a first part of a thermic module, a container with a second part of a thermic module and further containing a viscous depilatory composition.

Figure 2 depicts an improved dispensing device comprising a body and a first part of a thermic module, a container with a second part of a thermic module, a dispenser, and further containing a viscous depilatory composition.

Figure 3 depicts a variant of the device depicted on Figure 2, wherein the second part of the thermic module is removable from the container.

Figure 4 depicts a first embodiment of an insert * module according to the invention.

Figure 5 depicts a second embodiment of an insert module according to the invention.

Figure 6 depicts a further embodiment of an improved dispensing device according to the invention.

Reference will now be made in detail to the presently preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

The embodiments are described below in order to explain the present invention by referring to the figures.

With respect now to Fig. 1,therein is depicted a cross-sectional view of an improved device 10 according to the invention comprising a body 12 and a first part of a thermic module 14, a container 16 with a second part of a thermic module 18 and further containing a viscous depilatory composition 20. The body is dimensioned to receive both the first part of a thermic module, here a quantity of a heat transfer medium such as a fluid such as water, the second part of the thermic module and at least a portion of the container. The body desirably also include one or more breach elements 22, herein depicted as a plurality of thorns each upwardly depending from the inner * 15 base 24 of the body, and terminating in sharp end 26 at a * * distance from the inner base. These breach elements 22 are dimensioned in both length (height) and in configuration, particularly with respect to the configuration of their sharp ends to be adapted to pierce or otherwise breach a portion of the housing 28 of the second part of the thermic module which, in the embodiment shown, is affixed to the . * bottom exterior 30 of the container.

The container 20 also comprises at least one open end 32 which permits access to the viscous depilatory composition 34 contained within. In the depicted embodiment, the open end included a peripheral exterior skirt wall 36 encircling the open end, which skirt wall includes a base 38 which is dimensioned to mate with, or to rest upon the top end 40 of the sidewall 42 of the body.

While not essential, it is preferable that the base and the top end comprise or form a fluid tight seal when connected to one another so to deny the egress of the first part of a thermic module, particularly when such is a heat transfer liquid such as water. In the depiction shown, a simple press-fit interlocking seal is depicted, with a channel 44 present in the base adapted to receive a mating ridge 46 present on the top end and thereby form a liquid tight seal between the body 12 and the container 16, and defining an interior annular volume 48 within which first and second parts of the thermic module intermix and react to provide an exothermjc reaction.

The overall configuration and geometry of the improved device of the invention may vary from the preferred 41 15 embodiment illustrated on Fig.1, although such alternate embodiments are considered to fall with in the scope of the present inventive teaching. For example, it may be advantageous to provide a container which has a large open end in order to provide easy access using an applicator tool, e.g., brush, stick, wand, paddle, to the fluidified depilatory composition within the container. In another contemplated embodiment, the container has a generally circular cross-sectional shape which may be either constant, or which may be of increasing cross- sectional areas in sections distal from the base of the container.

In a further contemplated and preferred embodiment, the container has a generally elliptical cross-sectional shape which may be of a constant cross-sectional area when measured, but which desirably increase in crosssectional area in sections distal from the base of the container. A generally elliptical cross-sectional configuration of the container provides for increased heat transfer surface of the container in contact with the therrnic module which in turn, improves the rate of heat transfer to the depilatory composition contained within the container. In a still further contemplated embodiment, both the container and the body of the device have generally elliptical cross sections which provide both for improved heat transfer properties between the annular volume containing the thermic module, as well as for improved grip for a consumer holding or utilizing the device in a depilation process. It is also contemplated that the container 16 with a second part of a thermic module 18 and further containing a viscous depilatory composition 20 may form a unit which is used as a disposable insert module. The provision of such a disposable insert module facilitates the convenient reuse of the improved device according to the invention in that only the disposable insert module need be replaced between uses, and does not require the disposal of the entire : dispensing device. IS..

The relative volumes and dimensions of the body and the container may also vary depending upon the volume of S0* the depilatory composition to be included in the container, as well as the nature of the first part of the thermic * module, the nature of the second part of the thermic module I. : as well as the nature of the exothermic reaction and the amount of thermal energy released when the first and second parts of the thermic module are intermixed in the annular volume.

With respect to the thermic module, it is to be understood that any two or more materials which when intermixed provide an exothermic reaction may be used with the inventive device. Preferably however, it is desirably that the materials of the thermic module be relatively unreactive when separated from one another, but when intermixed, evolve at least 50%, preferably 70%, more preferably 80% and most preferably evolve at least 90% of the thermal energy of the exothermic reaction within 15 minutes, preferably within 10 minutes but most preferably within 5 minutes of intermixing the materials used to form the thermic module Preferably at least one part of the thermic module is liquid or fluid material which functions not only as a reactant in the ensuing exothermic reaction but which is also an effective heat transfer medium. Many liquids fall into consideration, particularly water, as well as largely aqueous compositions containing a minor proportion of one or more organic solvents, e.g., monohydric alcohols, : polyhydric alcohols, ethers, glycol ethers, and the like. IS..

According to certain particularly preferred embodiments the I.e first part of the thermic module is at least 90% water with the balance to 100% being one or more organic solvents but preferably is 100% water.

: * The second part of the thermic module is preferably : one or more materials selected from the group consisting of: calcium oxide, calcium chloride and hydrochloric acid.

Other exemplary useful materials include, without limitation, sodium hydroxide, anhydrous copper (II) sulfate, and sulfuric acid, although it is to be understood that other materials which are exothermically reactive with the first part of the thermic module may be used. Such may be in a liquid form, or in a solid such as in the form of a powder, block, compressed tablet, pellets, and the like.

Optionally all or part of the second part of the thermic module may be coated with a heat sensitive coating material, such as a wax. When a portion of the materials forming the second part of the thermic module are coated, thereby providing a mixture of coated and uncoated materials, a delayed heating effect can be provided to the improved device of the invention. This is due to the fact that upon mixing of the first and second part of the thermic module, the exothermic reaction is initiated by contact of the uncoated surfaces of the second part of the therrnic module with the first part of the thermic module, particularly when such is a liquid. However, little or no reaction between the coated surfaces of the second part of the thermjc module and the first part of the thermic module ::::. takes place due to the presence of the coating which forms a physical barrier. Once the exothermic reaction proceeds Is..

however, if a sufficiently high temperature is reached to is. soften and melt the coating, e.g., wax, the integrity of the coating deteriorates thus allowing for contact and * resultant reaction between the first and second parts of * the thermic module which where previously coated and thus, unreactive. The rate of such a delayed onset of the exothermic reaction may be controlled by one or more factors including: adjusting the proportion of the coated and uncoated second parts of the thermal module; adjusting the thickness of the coating present on the coated second parts of the thermal module; as well as selecting suitable coating materials according to their melting points and melting properties in view of the specific embodiment of the improved device. Other factors may also be controlled as well, e.g., providing two or more different materials to form the second part of the thermic module, as well as providing the second part of the thermic module as particles of various, but controlled particle sizes.

Preferably the self-heating dispenser does not permit heating of the depilatory composition to exceed about 60 C, at which temperature a risk of scalding or burning of the skin may arise.

While the embodiments disclosed in the accompanying figures contemplate the use of a fluid present in the annular volume as the first part of the thermic module, and the use of a solid composition present in a housing as the second part of the thermic module, it is nonetheless contemplated that the positions of these materials may be interchanged with one another without detracting from the operability of the invention.

The depilatory agent to be heated by use of the : 25 inventive device may be any depilatory composition which is highly viscous, pasty or which is a solid at room : temperature (approx. 20 C) but which fluidifies when heated to an elevated temperature of at least about 30 C, preferably at least about 35 C, but yet more preferably of at least about 40 C. By way of non- limiting example such useful depilatory compositions include one or more of: Aloe Andongensis Extract, Aloe Barbadensjs Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Aqua, beeswax, calcium carbonate, calcium hydroxide, calcium thioglycolate, Ceteareth-20, Cetearyl Alcohol, Ceteth-20, cetyl alcohol, Cocos Nucifera (Coconut) Oil, Colophonium, Corylus Americana (Hazel) Seed Oil, Corylus Avellana (Hazel) Seed Oil, dimethicone, Dipotassium Glycyrrhjzae, fragrance, glycerin, glyceryl stearate, Heljanthus Annuus (Sunflower) Seed Oil, methylparaben, mineral oil, propylene glycol, Rosin, sodium hydroxide, sodium lauryl sulfate, sodium silicate, Solvent Yellow 33, sorbitan sesquiisosteara, strontium hydroxide, Theobroma Cacao (Cocoa) Seed Butter, Thioglycolic Acid, tocopherol, tocopheryl acetate, urea, water, Yellow 11, Zea Mays (Corn) Starch and wax. Other known depilatory compositions which may be used with the present invention include those described in U.S. Patent 6, 203,784 and U.S. Patent 6,306,380, the contents of which are hereby incorporated by :::: reference.

Desirably the depilatory composition has a viscosity of between about 500 and about 700 cps at room temperature :" (approx. 20 C), but exhibits a reduced viscosity of between about 75 cps to about 100 cps, preferably about 80 - 90 cps * when heated to an elevated temperature of about 34 C.

The device of the invention may be formed of any materials of construction, with metals and synthetic polymers being preferred due to their relatively low cost, ready availability and easy of forming into the various parts of the device. Preferred metals include metals such as aluminum and steel, as well as various metal alloys and metal films and foils. Preferred polymers may be virtually any thermoplastic or thermosetting synthetic polymer, e.g., polyolefins such as polyethylene, polypropylene, polyamides such as various grades of "nylon" polymers, as well as polyalkylene therepthalates, such as polyethylene terephthalate and polybutylene terepthalate. The various parts of the device may be formed by conventional techniques such as by stamping when a metal, or casting or blow molding when a synthetic polymer.

In a preferred embodiment the housing containing the second part of the thermic module comprises at least a section, or a wall which is breachable by the piercing means. Advantageously such a section or wall is formed of a relatively thin material such as a metal foil, or thin film, or a cellulose containing membrane (e.g. cellophane) or sheet of a synthetic polymeric material which material ruptures when pressed into contact with the piercing means.

::::* The section or wall may be a single layer material or may be a multilayered laminate material of two or more materials as described herein.

While the piercing means depicted on Fig. 1 are depicted to be thorn shaped elements which are either integrally formed with the body, or which may be affixed * within the interior of the body it is nonetheless to be understood that other embodiments of these piercing means, as well as their configuration respective to the interior of the body are possible and considered to fall within the scope of the invention. The piercing means may be of any be any material, may be of any shape, and may be placed anywhere within or upon the improved device, it being required only that the piercing means be capable of piercing a portion of the housing containing the second part of the therrnic module and thus permitting the first and second parts of the thermic module to intermix.

According to particularly preferred embodiments of the invention the piercing means are positioned within the annular volume between the body 12 and the continer 16 of the device when the device is assembled for use.

The volume of the first part of the thermic module, and the second part of the thermic module should be selected such that the amount of heat evolved from the exothermic reaction is sufficient to provide sufficient heat to satisfactorily fluidify the viscous depilatory composition present in the container such that it may be readily applied to skin having unwanted hair by a consumer.

Such may be determined by empirically or experimentally :* determining the amount of thermal energy required to satisfactorily fluidify the viscous depilatory composition present in a container in an inventive device and thereafter selecting both the types and amounts of the first and second parts of a thermic module such that at * least the aforesaid determined amount of thermal energy * required is evolved by the exothermic reaction.

Figure 2 depicts an improved dispensing device comprising a crosssectional view of a further embodiment of an improved device 50 according to the invention comprising a body 12 containing and a first part of a thermic module 14, a container 16 having associated therewith a second part of a thermic module 18 wherein the container contains a quantity of a viscous depilatory composition 20. The body is dimensioned to receive both the first part of a thermic module, here a quantity of a heat transfer medium such as a fluid such as water, the second part of the thermic module and at least a portion of the container. The body further comprises a breach element 22, herein depicted as single thorn upwardly depending from the inner base 24 of the body, and distally terminating in sharp end 26 away from the inner base. The breach element 22 is dimensioned to be adapted to pierce or otherwise breach a portion of the housing 28 of the second part of the thermic module which, in the embodiment shown, is affixed to the bottom exterior 30 of the container.

The device 50 further includes a cap 52 which is mountable upon the open end 32 and includes a dispensing means 54 adapted to controllably dispense the depilatory :::: composition 34 from within the container 16 and onto the skin of the ultimate consumer or user of the device during a depilation process. In the embodiment show, the : dispensing means is a roller 54 which is mounted over or within a suitably sized slot 56 within the cap 52. During * use, the device 50 may be tilted or inverted so to permit the depilatory composition to flow towards and outward from the cap via the roller which is may be used to apply one or more layers of the depilatory composition onto the skin.

When a sufficient quantity of the depilatory composition is applied in an area of the skin, the device 50 may be returned to its upright position as shown in Fig. 2, allowing the depilatory composition to drain downwards into the container.

While Fig. 2 depicts a roller as a suitable and preferred dispensing means, it is to be understood that any configuration nor device which may be used to controllably dispense a quantity of the flowable depilatory composition may be used. By way of non-limiting example, further useful dispensing means comprise a simple slot or series of slots within the cap; a series of perforations within the cap; a mesh or screen element; a porous applicator element, e.g., sponge, membrane, textile or other fibrous applicator; a captive ball such as encountered with certain personal deodorant dispensers; a brush; as well as other device or configurations not described herein but which would be understood by a skilled artisan to be useful for such a purpose. Ii

The cap 52 of the device 50 depicted on Fig. 2 may be Ii a either permanently affixed to either the body 12 or the container 16 or both, or it may be removably affixed to either the body 12 or the container 16 or both. When the cap is permanently affixed to the body or to the container or to both, the device is suited for use as a single-use, * disposable dispensing device for the depilatory composition. When the cap is permanently affixed to the container, but the container is removably positionable within the, body, in such a configuration, a container comprising a quantity of the viscous depilatory composition, the cap and a part of thermic module forms a useful refill module for the improved device according to the invention. In such an embodiment, a single body may be reused a number of times with one or more refill modules; after the device is used to fluidify and apply a depilatory composition the refill module may be removed and discarded.

The body may be retained however, the first part of the thermic module reintroduced into the body, and the reconstituted body is ready for use again with a new refill module. In a still further embodiment, wherein the cap is removably mountable upon the body or container or both, such provides a refillable and reuseable device according to the invention. In such an embodiment the container may be refilled, and the body may be refilled as well.

Figure 3 depicts a further embodiment of a device 60 according to the invention which is a variant of the device depicted on Figure 2. In the embodiment depicted on Fig. 3, a plurality of breach elements 22 depend downwardly from I. the bottom exterior 30 of the container and are adapted to pierce or breach a portion of the housing 28 of the second part of the thermic module 18. In the depicted embodiment, the second part of the thermjc module is provided in a housing separate from the container. The housing a containing the second part of the thermic module may be a affixed to the bottom 24 of the body 12, but desirably is a removable housing 28 which may be inserted into, as well as removed from within the device by its ultimate user. According to the form of the device 60 depicted, the body may be used a

plurality of times as with each heating operation, a new housing 28 containing the second part of the thermic module may be inserted into the interior of the body 12, after which the container may be introduced into the body such that the housing 28 is breached, permitting the first and the second parts of the thermic module to mix and react exothermically thereby heating and fluidifying the viscous depilatory composition. In a subsequent later reuse of the device, a new thermic module need be supplied, and the container may be either refilled with a new quantity of the viscous depilatory composition or, a new refill module such as described with reference to Fig. 2 may be supplied, and the process may be thereafter repeated.

Figure 4 depicts a first embodiment of an insert module 70 according to the invention, which be a single use module, or may also be used as a refill module as particularly described with reference to the embodiments according to Figs. 2 and 3. The insert module is generally elliptical in cross-section and comprises a container 16 containing a quantity of a viscous depilatory composition 34 contained visible within an open end 32. The open end 32 is bounded by a peripheral exterior skirt wall 36 encircling the open end and is adapted to be received within, or to mate with appropriately dimensioned part of a body of a device, although such is not visible in the figure. Depending from the bottom exterior end 30 is a housing 28 containing a material which forms part of the thermic module used to fluidify the depilatory composition.

The cross-sectional configuration of the insert module 70 is particularly advantageous and preferred in several respects. The distance of the width, "w" measured Perpendicularly at the midpoint of the length, L" at the open end is desirably such that "w" is not more than 0.5 XL, preferably is not more than 0.4 XL and most preferably is not more than about 0.25 XL. Such a proportion provides both a broadened profile of the depilatory composition to be applied to the skin which is particularly desirable from a consumer standpoint. However more importantly, lower ratios of "w" to "L" ensure that more rapid fluidification of the viscous depilatory composition occur when the first and second parts of the thermjc module react exothermically.

The embodiment of depicted on Fig. 4 illustrates a container having an open end, such as is depicted on Fig. 1. It is to be understood however that the embodiment of Fig. 4 may be used with a cap 52 as well as has been previously described.

Figure 5 depicts a second embodiment of an insert module 80 according to the invention. The insert module 80 is substantially similar to that depicted on Fig. 4, but S further includes a cap 52 mounted over the open end of the container 16, as well as further including retaining means, here one or more clips 56 adapted to removably retain a housing 28 containing a part of the thermic module. In the embodiment shown, two clips 56 extend downwardly from the bottom exterior surface 30 of the container 16, although only one if visible in the figure. The clips 56 are used to grip opposite sides of the housing but are sufficiently flexible or deformable to permit for the removal of, and the replacement of the housing 28 containing a part of the thermic module. Such a configuration permits for the reuse of the inventive device, as the thermic module 28 may be replenished generally in accordance with the principles outlined with reference to Fig. 3.

In further embodiments of the invention, the inventive device contains an internal or external vent or pressure release valve; an example of a vent to release vapor evolved from reaction is described in U.S. Patent Application Publication 2002/017291, the contents of which are hereby incorporated by reference. When included, such a vent permits for the release of any reactants of the ::::. thermic module which may vaporize (e.g, steam) and may be

used to safely vent such reactants from the device. Such :. an embodiment is depicted on Figure 6 which illustrates a * cross-sectional view of an improved device 90 according to the invention substantially similar to that depicted on * Figure 1 comprising a body 12 and a first part of a thermic 811S module 14, a container 16 with a second part of a thermic module 18 and further containing a viscous depilatory composition 20. In addition to the further like elements found in the embodiment of Figure 1, the embodiment of Fig. 6 further comprises at least one pressure release valve 62 which permits for the venting of gases from the interior of the body which gases may be the resultant product or byproduct of the exothermic reaction between the first part and second part of the thermic module. Preferably however, as is depicted on Figure 6, at least one pressure release valve 62 is provided near the bottom, viz., proximate or adjacent to the inner base 24 of the body, and a second pressure release valve 62 provided in a position distal from the first valve, here depicted near the open end 32 of the device. In such an arrangement, when the device 90 is in its upright position such as normally expected when stored prior to or between usages, or when the device is in an inverted position, such as which may be expected when the device is grasped and is used to dispense the depilatory composition to the skin, at least one of the pressure relief valves 62 are likely to be in communication with any gas which may be present and thus permit venting of the gas from the interior of the body 12 as may be :.::. necessary. S... ..DTD: In another embodiment which is not illustrated, control of the buildup of any gases may be accommodated by : ,. ensuring that the volumetric quantity of the first part 12 *5S * 20 of the thermic module is insufficient to completely fill * the interior volume of the device 90 with the container 16 I...

installed therein, thus creating an available headspace above the level of the first part 12 of the thermic module in the interior of the body 12 which is unfilled by the quantity of the first part 12 of the thermic module.

Thereby, any gases generated by the exothermic reaction between the first part 12 and the second part 18 of the thermic module may be released and contained within this available headspace. In certain configurations, the necessity of one or more pressure valves may be obviated.

In another embodiment of the invention, the reusable self- heating dispensers of the invention can also have a thermochromic indicator as part of the dispenser as is described in U.S. Patent 6,174, 319, the contents of which are hereby incorporated by reference. The color change of the thermochromjc material provides an indication that the depilatory material is at an appropriate temperature for application to the body.

While the invention is susceptible of various modifications and alternative forms, it is to be understood that specific embodiments thereof have been shown by way of example in the drawings which are not intended to limit the invention to the particular forms disclosed; on the contrary the intention is to cover all modifications, equivalents and alternatives falling within the scope and S...

***. spirit of the invention as expressed in the appended claims. * S * *5* S.. S. * S... S. * * . . S *S

Claims

CLAIMS: 1. A self-heating dispensing device comprising: a body, a first

part of a thermic module comprising a heat transfer medium, a container containing a viscous depilatory composition, and a second part of a thermic module.
2. A self-heating dispensing device according to claim 1 wherein: the container containing a viscous depilatory ::. composition, and a second part of a thermic module *S..

comprise a unitary disposable insert module. S.

:
3. A self-heating dispensing device according to claim 1 : 20 which further comprises piercing means. S. * I...
4. A self-heating dispensing device according to claim 3 wherein the piercing means are located within the annular volume between the body and the container of the device.
5. A self-heating dispensing device according to claim 3 wherein the piercing means are one or more thorns each upwardly depending from the inner base of the body.
6. A self-heating dispensing device according to claim 1 wherein the heat transfer medium is water.
7. A self-heating dispensing device according to claim 1 wherein the second part of the thermic module comprises one or more materials selected from the group consisting of: calcium oxide, calcium chloride and hydrochloric acid, sodium hydroxide, anhydrous copper (II) sulfate, and sulfuric acid.
8. A self-heating dispensing device according to claim 7 wherein the second part of the thermic module comprises one or more materials selected from the group consisting of: calcium oxide, calcium chloride ::. and hydrochloric acid. *..S * S SI..
9. A self-heating dispensing device according to claim 1 wherein when the first part of the thermic module is I. * 20 intermixed with the thermic module, the resultant exothermic reaction evolves at least 50% of the SI..

thermal energy of the exothermic reaction within 15 minutes of intermixing.
10. A self-heating dispensing device according to claim 1 wherein when the first part of the thermic module is intermixed with the thermic module, the resultant exothermic reaction evolves at least 70% of the thermal energy of the exothermic reaction within 15 minutes of intermixing.
11. A self-heating dispensing device according to claim 1 wherein when the first part of the thermic module is intermixed with the thermic module, the resultant exothermic reaction evolves at least 80% of the thermal energy of the exothermic reaction within 15 minutes of intermixing.
12. A self-heating dispensing device according to claim 1 wherein when the first part of the therrrtjc module is intermixed with the thermic module, the resultant exothermic reaction evolves at least 50% of the thermal energy of the exothermic reaction within 10 minutes of intermixing. * 0* * * * *S..

* S. S
13. A self-heating dispensing device according to claim 1 wherein when the first part of the thermic module is : intermixed with the thermic module, the resultant exothermic reaction evolves at least 50% of the es thermal energy of the exothermic reaction within 5 minutes of intermixing.
14. A method of removing hair from the skin of a person or mammal in need thereof or desirous thereof which comprises of piercing the piercable membrane of the reusable self-heating dispenser of claim 1 and applying the heated depilatory agent to the skin.
15. A kit for providing a reuseable self-heating dispensing device comprising: a body adapted for containing a first part of a thermic module comprising a heat transfer medium, and, as a unitary disposable insert module a container containing a viscous depilatory composition, and a second part of a thermic module adapted to be at least partially inserted within the body.
16. A method of reusing the reusable self-heating dispenser of claim 2 which comprises: (a) removing a disposable insert module of the selfheating dispenser; (b) emptying the contents of body; (c) refilling the body with the first thermic module; (d) inserting a new disposable insert module into the *S.. body. S. * . * *e. *S* * 20 0* S **** S. * * * S S *S