Patent Application
20090283106
The present invention is directed to method of providing a hair care benefit by the use of a portable moist heat delivery system and a hair care active. In particular, the present invention is directed to applying a hair care composition containing a hair care active to the hair, and then applying a portable moist heat delivery system that generates water vapor and provides moist heat to the hair.
A variety of approaches have been developed to deliver hair care actives to the hair. A common method of providing a hair care active is through the use of hair care compositions containing actives such as actives to deliver hair conditioning, hair shine, smooth hair, soft hair, healthy hair, hair strand alignment, dandruff free hair, and combinations thereof. Additionally, traditional methods of conditioning hair combine the use of hair conditioners with heat such as a hot towel or a hair dryer. However, these heat treatments are either difficult and inconvenient to use, or do not provide heat of a consistent temperature that is safe to use on the hair for a length of time sufficient to deliver a hair care benefit. Additionally, use of a hair dryer cannot provide a moist heat to the hair.
Disposable heat wraps have become a popular way of applying heat to relieve discomfort of temporary or chronic body aches and pains. Disposable heat wraps typically comprise an exothermic composition for generating heat, wherein the exothermic composition typically comprises metal powder, salts, and water that allows the exothermic composition to release heat upon oxidation of the metal powder. Other disposable or reusable devices can use energy produced by neutralization of acids and bases; heat of hydration of inorganic salts; re-heatable gels; and electrical energy to produce heat. Such devices usually produce heat but contain little moisture.
Based on the foregoing, there is a need for a moist heat source which is easy and convenient to use with a hair care active, and which also provides a consistent temperature to the hair for a length of time sufficient to deliver a benefit to the hair None of the existing art provides all of the advantages and benefits of the present invention.
A method of providing benefits to the hair comprising: (i) applying a hair care composition to the hair; (ii) applying a portable moist heat delivery system to the hair, wherein the portable moist heat delivery system comprises: a water vapor generating portion comprising a water vapor source and a heat source; and a water vapor-air regulating portion located at a hair-facing side of the water vapor generating portion, the water vapor-air regulating portion comprising a water vapor-air mixing layer, a water vapor-air distribution layer, and optionally a hair contact layer; the water vapor generating portion and the water vapor-air regulating portion being in fluid communication; and the water vapor-air regulating portion having a latent heat delivery surface disposed adjacent the water vapor-air regulating portion which delivers moist heat at a pre-selected temperature range and about 15% to about 95% of the moist heat is latent heat of condensation, while maintaining hair temperature less than about 43° C.; (iii) wherein the benefit is selected from the group consisting of hair conditioning, hair shine, smooth hair, soft hair, healthy hair, hair strand alignment, dandruff free hair, and combinations thereof.
A method of providing a benefit to the hair comprising (i) providing a portable moist heat delivery system comprising a steam generating portion comprising a steam source and a heat source; and a dew point reduction portion located at a hair-facing side of the steam generating portion, the dew point reduction portion comprising a vapor-air mixing layer, a vapor-air distribution layer, and optionally a hair contact layer, the steam generating portion and the dew point reduction portion being in fluid communication and the water vapor-air regulating portion having a latent heat delivery surface disposed adjacent the water vapor-air regulating portion; (ii) applying the portable moist heat delivery system to the hair of a user; (iii) initiating heating of the portable moist heat delivery system; and (iv) supplying a vapor-air mixture generated by the portable moist heat delivery system to the hair of the user; wherein the vapor-air mixture provides latent heat, resulting in hair benefit within about 1 minute to about eight hours from the initiation of heating of the portable moist heat delivery system; and wherein hair temperature is maintained below about 43° C.; and wherein the benefit is selected from the group consisting of conditioned hair, smoother hair, shinier hair, softer hair, healthier hair, dandruff free hair, and combinations thereof, and further wherein a hair care active is incorporated into the steam-generating portion, into the steam source, or into the dew point reduction portion.
The method of delivering a hair care benefit of the present invention delivers a benefit such as conditioning, hair shine, smooth hair, soft hair, healthy hair, hair strand alignment, dandruff free hair by the use of a hair care composition, comprising a hair care active, in combination with the use of a portable moist heat delivery system of the present invention. The heat delivery system can be a single-use disposable system or can be incorporated into a reusable or partially reusable system. It is believed that the moist heat delivered by portable moist heat delivery system acts to swell the hair thus enhancing the penetration of the beneficial hair actives. It is also believed that the moist heat delivered by the portable moist heat delivery system may affect the ability of materials on the hair surface, particularly the high molecular weight lubricants, such as silicone, to reduce friction, by affecting their distribution on the hair surface.
The portable moist heat delivery system of the present invention delivers a moist heat which can be applied to the skin and hair for a length of time up to about eight hours. This heat does not exceed a temperature which would burn the skin or damage the hair.
The invention can comprise, consist of, or consist essentially of the elements and limitations of the invention described herein, as well as any of the additional or optional ingredients, components, or limitations described herein.
As used herein, “water vapor” refers to water in the gaseous state. “Water vapor-air mixture” and “water vapor-air mixing” refer to adding air to “water vapor” as defined herein. The energy added to accomplish the phase change from liquid water to water vapor is latent heat of evaporation. The latent heat of evaporation energy is released upon the phase change of condensation of water vapor to liquid water and referred to as latent heat of condensation. The word “steam” as used herein also refers to water in the gaseous state and differs from the term “water vapor” in that steam refers only to water vapor and not a mixture of water vapor and liquid water droplets.
As used herein “dew point” temperature refers to the temperature to which a water vapor-air mixture must cool before water therein begins to condense.
“Humidity ratio” is the ratio of the weight of water vapor to the weight of dry air.
“Latent heat”, as used herein refers to the amount of energy in the form of heat released or absorbed by a substance during a change of phase (i.e. to or from solid, liquid, or gas).
“Moisture”, as used herein refers to water.
“Moist heat”, as used herein, refers to heat wherein about 15% to about 95% of the transferable heat energy is in the form of latent heat of condensation of water vapor. As water vapor and water vapor condensation are associated with moist heat, moist heat includes a moisture component. The moist heat delivery system may also transfer water vapor and, when condensation occurs and latent heat released, liquid water.
A “pre-selected temperature”, as used herein, may include the stated temperature plus or minus 1° C. or alternatively plus or minus 2° C. The term “median particle size” means that there are approximately as many particles that have a size larger than the designated median size as there are particles that have a size smaller than the designated median size.
Other definitions are provided as necessary as they occur within the description of the invention.
All caliper-measured thicknesses disclosed herein are measured according to ASTM Method No. D5729, unless otherwise specified.
All basis weights disclosed herein are measured according to ASTM Method No. D3776, unless otherwise specified.
All air-permeabilities disclosed herein are measured according to ASTM Method No. D737, unless otherwise specified.
All moisture vapor transmission rates (MVTR) disclosed herein are measured according to ASTM Method No. E96 unless otherwise specified.
All percentages, parts and ratios are by weight, unless otherwise specified. All such weights as they pertain to listed ingredients and components are based on the specific ingredient level and, therefore, do not include carriers or by-products that may be included in commercially available materials, unless otherwise specified.
The benefits of moist heat, such as swelling the hair to enhance the penetration of the hair care actives, and/or enhance the distribution of materials, such as silicone, on the hair surface to reduce friction, can only be achieved if a moist heat device delivers a particular, effective amount of moist heat. In order to deliver an effective amount of moist heat, the portable moist heat delivery system of the present invention includes a water vapor generating portion comprising a water vapor source and a heat source; and a water vapor-air regulating portion located at a hair-facing side of the water vapor generating portion, the water vapor-air regulating portion comprising a water vapor-air mixing layer, a water vapor-air distribution layer a latent heat delivery surface, and optionally a hair contact layer; the water vapor generating portion and the water vapor-air regulating portion being in fluid communication. Specifically, the structure is designed to provide water vapor and air mixing and distribution to provide rapid, safe, efficient and sustained moist heat production and transfer. Embodiments of the portable moist heat delivery system are described in detail in copending U.S. application Ser. No. ______, entitled “Portable Moist Heat System”, filed on May 13, 2009.
In one embodiment, the water vapor generating portion generates water vapor which is at a temperature of from about 50° C. to about 70° C. As the water vapor is formed not only is the water vapor warmed but also heat is stored as latent heat of vaporization. In order to generate water vapor, the water vapor source, must heat quickly and deliver a high water vaporization rate for a period of time of at least about 10 minutes and preferably about 30 minutes or more. The stored heat of vaporization is released when the water vapor condenses. Water vapor is an ideal candidate to transfer heat because of the magnitude of heat transfer by latent heat when it condenses, and because water vapor is easily generated and available. In exemplary embodiments described herein, heat for generating the water vapor is generated using an exothermic thermal composition such as for example an iron based thermal composition as disclosed in U.S. application Ser. No. 11/233,916. However, as one skilled in the art will appreciate, other thermal materials compositions and/or sources of heat and/or other energy sources may likewise be used to generate heat in the practice of the invention.
In an exemplary embodiment, the water vapor generating portion includes a thermal composition for generating heat and water available for vaporization. Optionally, these components may be intermixed.
The water vapor-air regulating portion of the moist heat system has multiple purposes and functions. The first function of which is to allow sufficient air to enter the water vapor generating portion to support the exothermic reaction. Providing sufficient air to support the exothermic reaction is important because the permeable portion of the portable moist heat delivery system is worn against the hair. To vaporize the water in the exothermic composition, the temperature of the composition can be as high as about 70° C. However, because human skin can burn at temperatures of about 43° C. or higher, it must be protected from the hot exothermic composition. Thus, in the present system, as water vapor is generated, it exits the water vapor generating portion through/into the water vapor-air regulating portion. As the water vapor passes through the water vapor-air regulating portion, the water vapor is mixed with air and distributed such that the dew point temperature of the vapor-air mixture is lowered to about 43° C., a temperature which will not burn the skin and/or hair. Thus, the water vapor-air regulating portion also safeguards the skin and/or hair against the high temperature of the water vapor generated in the water vapor generating portion. This also protects the hair from heat damage.
Previously it was thought that the temperature of the water vapor exiting a moist heat device must be lowered to less than about 50° C. in order to prevent skin burns. However it has been found that it is not only or primarily the temperature of the water vapor that is important for preventing burns, but rather the energy content of the exiting water vapor and its ability to transfer energy to the skin is important.
However, it should be recognized that contact with the skin or hair with a high temperature source will result in a burn only if the skin/hair is unable to dissipate energy it receives. Thus, energy transfer as well as temperature is determinative of the potential for damage. Typically, in dry or conductive heat transfer a burn occurs when the skin temperature exceeds about 43° C. However, without wishing to be held to any theory, it is believed that in the case of moist heat, much of the energy is transferred via latent heat of condensation. Thus, even though the temperature of water vapor air mix may be higher, e.g., about 50° C., the skin will not burn if the amount of energy transferred by the water vapor is insufficient and/or transferred at a rate insufficient to elevate the skin temperature above 43° C. and/or dissipated at a rate sufficient to maintain the skin temperature at about 43° C. or less.
Thus, the system of the present disclosure enables one to use temperatures higher than about 43° C. without harm to human skin or hair. Previously, it was believed that the temperature per se of the water vapor exiting a moist heat device must be lowered to less than about 50° C. as measured by a dry bulb thermometer or thermocouple in order to prevent bums. However, the potential for tissue damage and/or energy transfer is not reliably reflected in the temperature as measured by conventional dry bulb or thermocouple, but rather is more reliably related to the dew point temperature of the water vapor. Unlike the dry bulb temperature, the dew point temperature is related to the amount of water vapor in the gas mixture. With the portable moist heat delivery device of the present invention the skin and/or hair is contacted with water vapor which causes the water vapor to condense and release its latent heat via condensation. With such a mode of heat transfer, the condensation of the water vapor releases a high quantity of energy at a fast rate. Thus, to prevent skin and/or hair burn, it is important to control the condensing temperature of the water vapor-air mixture, and not merely the dry bulb temperature of the water vapor-air mixture. The condensing temperature of the water vapor-air mixture is its dew point temperature.
As shown in the psychrometric chart of
As can be seen in the psychrometric chart of
Point B represents a lower humidity, or less saturated, water vapor-air mixture at a water vapor-air ratio of about 0.052 kg water/kg dry air. To have the same energy content as the water vapor-air mixture of Point A, the water vapor-air mixture at Point B has a dry bulb temperature of about 60° C. (about 140° F.). When a water vapor-air mixture such as that at Point B condenses on the skin and/or hair, it will condense at about 40.6° C. (about 105° F.). As it condenses, the energy transfer rate will be very high but will not burn the skin and/or hair even though its dry bulb temperature is about 60° C. (about 140° F.), since its condensing temperature or dew point is only about 40.6° C. In contrast, when a water vapor-air mixture at Point A condenses on the skin and/or hair, it will condense at about 43.3° C. (about 110° F.) and rapidly transfer its latent heat content, posing a great risk of burn even though its dry bulb temperature is significantly less that that of the water vapor-air mixture at Point B.
Thus, unlike the prior art, the moist heat delivery system in the present invention avoids skin and/or hair burns by regulating the water vapor-air mixture ratio as opposed to regulating the dry bulb temperature of a water vapor-air mixture. By regulating the water vapor-air ratio to less than about 0.065 kg water/kg dry air, and alternatively to less than about 0.060 kg water/kg dry air, the dew point temperature of the water vapor-air mixture will be less than about 43° C. One of the advantages in controlling the dew point temperature of the moist heat delivery system is that the thermodynamics of the system provides a temperature modulation wherein the transfer of latent heat is modulated by the skin temperature (i.e. the latent heat is transferred at the dew point. Thus, transfer will not occur unless the skin temperature is at or below the dew point of the water vapor).
The portable moist heat delivery systems described herein selectively direct water vapor against a user's hair at the desired dew point temperature of from about 36° C. to about 50° C., alternatively from about 36° C. to about 45° C., alternatively from about 36° C. to about 42° C., and alternatively from about 38° C. to about 40° C. The system can direct water vapor to the hair for a period of from about twenty seconds to about eight (8) hours, alternatively from about twenty minutes to about four (4) hours, alternatively from about one (1) minute to about sixty (60) minutes, alternatively from about fifteen (15) minutes to about thirty (30) minutes, alternatively from about one (1) minute to about twenty (20) minutes, alternatively from about twenty (20) minutes to about forty (40) minutes and alternatively from about one half (½) hour to about two (2) hours. The maximum skin temperature and the length of time of maintaining the skin temperature at the maximum skin temperature may be appropriately selected by a person needing such treatment such that the desired benefits are achieved without any adverse events such as skin and/or hair burns. The water vapor-air regulating portion ensures that a desired amount of moist heat is delivered to a user's hair without adverse effects.
The water vapor-air regulating portion of the moist heat system has a water vapor air mixing layer and a water vapor air distribution layer. Further, as a function of the water vapor-air regulator is to adjust the proportion of water vapor to air, the water vapor-air regulating portion must be in fluid communication with the water vapor generation portion with water vapor passing freely between the water vapor air generation portion and the water vapor-air regulator portion. In an exemplary embodiment, the water vapor-air regulation portion is adjacent the water vapor generation portion. Additionally, the water vapor-air regulating portion needs a supply of air to accomplish the water vapor-air ratio adjustment but as a specific ratio or ratio range is desired regulation of the air supply is desirable. Air supply may be regulated, for example, by control of the density and/or porosity of the materials used to construct the system or, alternatively, by the use of channels and apertures in water and/or air impermeable materials.
The interface between the water vapor-air regulating portion and end user is the latent heat delivery surface proximate the hair and optionally a hair contact layer. In some embodiments that latent heat delivery surface and/or hair contact layer may contact or partially contact the hair. In other embodiments, it may be desirable to have a small air gap between the latent heat delivery surface and/or hair contact layer and the hair. In the moist heat delivery system the generated water vapor is preferentially directed toward the latent heat delivery surface. The water-vapor may be passed though the latent heat delivery surface to the hair, water-vapor may condense at the latent heat delivery surface/ hair contact layer transferring the latent heat energy to the user or, alternatively, a combination of water vapor condensation and water- vapor transfer may occur.
The terminology of latent heat delivery “surface” has been selected. However, surface is not intended to be limited to any particular geometric shape, and includes, but is not limited to, planar surfaces, contoured surfaces, and irregular surfaces. The latent heat transfer surface may comprise a layer of material. Optionally, the latent heat delivery surface may be integrally attached to the water vapor-air regulator portion, and/or a surface of a portion of the water vapor-air regulator portion. Alternatively the latent heat delivery surface may be a part of a reusable holder for the system, for example. In those embodiments including a hair contact layer, the latent heat delivery surface may be in contact with the hair contact layer.
The water vapor generating portion of the present invention contains at least one water vapor source and a heat source. The water vapor source can generate energy and water vapor in any number of ways. Non-limiting examples of heat sources include by chemical energy; energy produced by neutralization of acids and bases; heat of hydration of inorganic salts; reheatable gels; and electrical energy. Water vapor sources can be combined with the heat source. For example an exothermic heat cell can include a mixture of fuel (i.e., the heat source) and water and/or water held in a water manager (such as a gel) as the water vapor generating portion of the moist heat delivery system. Alternatively, the water and heat source can be separated with the water being supplied from a reservoir or applied to a surface, such as the hair, and then contacted with the heat produced by the heat generating source. In water vapor generating portions that comprise energy sources that are not compatible with water, for example an electrical element, the energy source can be used to heat separate water-containing elements to produce water vapor. A non-limiting example of a water vapor generating portion useful in the present invention uses an exothermic composition including water in a water manager formed in at least one water vapor generating heat cell. The moist heat delivery system may contain a single heat cell or a plurality of heat cells. In certain embodiments, a plurality of heat cells is particularly useful in the system of the present invention. A plurality of heat cells allows for flexible systems of various size and shape. In addition, the use of a plurality of heat cells may allow for an easy control of the water vapor-air mixing ratio for controlling the dew point. For example, the dew point temperature for a fixed water-vapor mixing and aeration design can be increased/decreased by increasing/decreasing the number of heat cells. Further, the duration of heating and total energy delivered can be controlled by varying the number of heat cells used per unit area of vapor generating portion. The greater the number of heat cells per area, the longer the duration of heating provided. The fewer number of heat cells per area, the shorter the duration of heat provided. In certain embodiments, it may be desirable to use a combination of a moist heat delivery system, such as described herein, and one or more other types of heat cells, such as dry heat cells.
In one exemplary embodiment, the thermal energy for generation of water vapor is provided by an exothermic heat cell comprising a particulate exothermic composition. The exothermic composition may comprise a flowable particulate pre-mix and a brine solution. The exothermic compositions disclosed in U.S. application Ser. No. 11/233,916 may be suitable in certain embodiments.
Particulate exothermic compositions have both desirable features and certain considerations that must be addressed to achieve the desirable features. For example, the performance of an exothermic heat cell can be impacted by the particle size of the particulate components of the exothermic composition in two main ways. First, variation in particle size of the particulate components of an exothermic composition can lead to particle separation or segregation within an exothermic composition. Particle size directly affects particle mobility and particulate components can vary in their mobility, resulting in particle separation or segregation. Changes in the exothermic composition due to particle segregation can lead to less than optimal or desired reaction behavior.
The exothermic compositions defined herein comprise particulate components having defined median particle size ranges such that the exothermic compositions resist particle separation or segregation. It is contemplated, however, that particulate components having median particle size ranges above or below the ranges defined herein are suitable for use in the exothermic compositions defined herein.
The second way that performance of exothermic heat cells can be impacted by the particle size of the particulate components of the exothermic composition is that particle size affects accessibility of air through the particulate exothermic composition. In order to support and sustain a vigorous exothermic reaction for releasing water vapor, the particulate exothermic composition should be porous in order to allow free access of air to the reactants of the particulate exothermic composition. The particulate exothermic composition should be porous even with initially high water content (for high water vapor generation) and remain porous throughout the reaction. To be and remain porous, the particulate exothermic composition needs to have an efficient water manager component and the particle sizes of the components of the exothermic composition should exhibit loose particle packing behavior. Without wishing to be bound by any theory, it is believed that proper porosity and maintaining porosity is an important factor in creating heat cells that have long periods of heat production (such as up to 24 hours) and in creating a composition that has a consistent, reproducible behavior in a plurality of heat cells.
In one embodiment, the heat cells of the present disclosure may comprise a particulate exothermic composition that provides for reliable heating and accordingly reliable and substantial water vapor generation over time frames of a few minutes to hours when the heat cells are incorporated into portable moist heat delivery systems. The exemplary particulate exothermic composition comprises a particulate pre-mix composition and a brine solution.
Components of the particulate premix composition include iron powder, carbon, absorbent gelling material, and water, which components are described in detail hereinafter. Components of the brine solution include a metal salt, water, and optionally a hydrogen gas inhibitor such as sodium thiosulfate. The particulate exothermic compositions defined herein are generally prepared by constructing the particulate premix composition and rapidly dosing the premix with the brine solution to result in the formation of the exothermic composition.
For use in a moist heat device a particulate exothermic composition should have the ability to provide fast initial heating and also provide heat for a sustained period of time. Typical exothermic heat devices known in the art generally can either provide high levels of heat rapidly but last only a few minutes, or they can provide heat for a sustained period of time, but can take up to about 30 minutes to heat. The present invention provides both rapid and sustained heating achieved in part by the choice of components within the particulate exothermic composition. By way of non-limiting example, by modifying component particle size, the speed of heating, duration of heating and temperature of the exothermic reaction can be controlled.
By way of illustration, one particular method of modifying the exothermic reaction involves using iron powder having a median particle size of about 200 μm and an absorbent gelling material having a median particle size of about 300 μm, wherein the median particle size ratio of absorbent gelling material to iron powder is about 1.5:1. This particular ratio of absorbent gelling material to iron powder provides for an exothermic composition that exhibits rapid initial heating and water vapor generation, which has been difficult to achieve with conventional exothermic compositions. It is believed that attempts to incorporate a high level of moisture in conventional exothermic compositions results in water in the interstitial particle voids which restricts oxygen flow and slows the rate of initial heating. To keep water out of the interstitial particle void volume a water manager is often incorporated into exothermic compositions to absorb excess moisture. However, most water managers such as vermiculite and absorbent gelling material have particle sizes that are significantly larger than the iron particles due to the common practice in the art of using very fine iron particles based on the belief that the iron oxidation reaction is limited by the surface area of the iron particles. Thus, it has been conventionally believed that small iron particles increase the iron surface area. However, porosity is also an important factor in reaction rate. Thus, the size disparity between the particles of the water manager and iron can promote particle segregation and tight particle packing, thus inhibiting the reaction. For example, when the particle size ratio of the water manager to iron particles is greater than about 7:1, tight particle packing and inhibition of the reaction can occur.
Thus, with the present invention, exothermic compositions having a particular median particle size ratio of absorbent gelling material to iron powder are used to achieve the desired packing. The selected particle size distribution and ratio facilitates prevention of excess water in the interstitial particle void volume, and prevention of particle segregation and packing with void volumes such that faster rates of initial heating are achieved. The median particle size ratio of absorbent gelling material to iron powder in the present invention is from about 10:1 to about 1:10, alternatively from about 7:1 to about 1:7, alternatively from about 5:1 to about 1:5, and alternatively from about 3:1 to about 1:3.
It is believed that the exemplary particulate exothermic compositions defined herein release heat upon oxidation of the iron powder. There is no particular limit to the purity, kind, size, etc. of the iron powder as long as it can be used to produce heat generation via an oxidation reaction with water and air.
The particulate exothermic compositions of the present invention comprise one or more iron powder components at concentrations ranging from about 10% to about 90%, alternatively from about 30% to about 88%, and alternatively from about 50% to about 87%, by weight of the dry premix composition. Additionally, the system of the present invention can comprise greater than about 0.1 g iron powder/cm2 of the water vapor generating portion.
Non-limiting examples of suitable sources for the iron powder include cast iron powder, reduced iron powder, electrolytic iron powder, scrap iron powder, sponge iron, pig iron, wrought iron, various steels, iron alloys, treated varieties of these iron sources, and combinations thereof.
Sponge iron is one source of the iron powder which may be particularly advantageous due to the high internal surface area of sponge iron. As the internal surface area is orders of magnitude greater than the external surface area, reactivity may not be controlled by particle size. Non-limiting examples of commercially available sponge iron include M-100 and F-417, which are available from the Hoeganaes Corporation located in New Jersey, USA.
Iron powder having a median particle size of from about 50 μm to about 400 μm, alternatively from about 100 μm to about 400 μm, and alternatively from about 150 μm to about 300 μm is suitable for use herein. Other sizes may likewise be suitable so long as the ratio of the median particle size of iron to the median size of absorbent gelling material is such that the size and distribution of particles provides for a particle packing with sufficient void volumes to allow substantially free access to air.
The median particle size of the iron powder, and any other particulate component defined herein, can be determined using a sieve method such as the method disclosed in ASTM Method B214. Generally, the particles are screened through a series of sieves consisting of different sizes, and the weight fraction of particles retained on each screen is measured. The weight fraction of the particles in each screen is then used to construct a cumulative weight distribution curve. The cumulative weight distribution curve is constructed by plotting particle size against the cumulatively added weight percent of particles less than the particle size retained on the next largest sieve. A median diameter is determined from the cumulative weight distribution curve, wherein the median diameter is defined as the particle size that corresponds with 50% of the cumulative weight. Details on constructing a cumulative weight distribution curve is described in “Methods of Presenting Size Analysis Data” in Particle Size Measurement, pages 153-156, 4th Edition, Terrence Allen, (1990).
In exemplary particulate exothermic compositions according to one embodiment of the present invention comprise one or more carbon components at concentrations ranging from about 1% to about 25%, alternatively from about 1% to about 15%, and alternatively from about 1% to about 10%, by weight of the composition.
Non-limiting examples of carbon suitable for use herein include activated carbon, non-activated carbon, and mixtures thereof. The carbon component has a median particle size of from about 25 μm to about 200 μm, and alternatively from about 50 μm to about 100 μm. Activated carbon is particularly useful. In addition, combinations of the various carbons are also useful.
Activated carbon is extremely porous in the inner structure giving it particularly good oxygen adsorption capabilities. In fact, activated carbon has the ability to adsorb oxygen extremely well when the activated carbon is wetted, thus allowing for the activated carbon to function as a catalyst in the oxidation reaction. Thus, in the presence of a high water absorbing material such as for example absorbent gelling material or vermiculite, the availability of water to the carbon may be restricted and it may be important that activated carbon be pre-wetted prior to the addition of high water absorbing materials. Without being bound by theory, it is believed that activated carbon should be pre-wetted because of its inability to compete effectively against the high water absorbing material when the particulate pre-mix is dosed with brine. When activated carbon is pre-wetted, heat of adsorption is released such that the water adsorbed by the activated carbon is in a thermodynamically low energy state and thus the water does not migrate from the activated carbon to the high water absorbing material. Therefore, the activated carbon remains wet when the high water absorbing material is added, and is able to function as a catalyst for adsorbing oxygen.
In addition to its catalytic behavior, activated carbon has the capacity to absorb water, and can also serve as a water manager for the exothermic reaction. In addition, active carbon can adsorb odors such as those caused by the oxidation of iron powder.
Non-limiting examples of suitable carbons include activated carbon prepared from coconut shell, wood, charcoal, coal, bone coal, and the like, and combinations thereof are suitable for use herein, but those prepared from other raw materials such as animal products, natural gas, fats, oils, resins, and combinations thereof are also useful. There is no limitation to the kinds of activated carbon used. However, the preferred activated carbon has good oxygen adsorption capabilities. An example of a commercially available activated carbon includes activated carbon available from MeadWestvaco located in Covington, Va., USA.
Additionally, the amount of carbon in the particulate exothermic compositions defined herein should be minimal in order to maximize the interstitial particle void volume. Carbon is typically the finest particle component and excess carbon can result in the carbon filling up the interstitial particle void volume between the larger particles of the other materials. Thus, the amount of carbon needed for presenting an exothermic composition for generating moist heat is generally significantly lower than that used in conventional exothermic compositions because of the relatively high level of absorbent gelling material used herein. Therefore, the carbon herein is mainly used for its catalytic activity and minimally for its water retention property.
A low level of pre-wetted carbon is also highly desirable for high speed manufacture of the heat cells of the present invention because a low level of pre-wetted carbon enables the pre-mix to readily absorb the brine solution. With a high level of carbon, the brine absorption rate is slow due to wetting of the carbon. Thus, a low level of pre-wetted carbon significantly increases the rate of manufacture of the heat cells defined herein.
The particulate exothermic compositions of the present invention comprise one or more absorbent gelling materials at concentrations ranging from about 1% to about 25%, alternatively from about 1% to about 15%, and alternatively from about 1% to about 10%, by weight of the composition.
The absorbent gelling material (“AGM”) suitable for use herein enables the retention of water physically or chemically within the particulate exothermic compositions of the present invention. In particular, the absorbent gelling material serves the function of storing water for release and releasing the water in a controlled manner. Upon heating, stored water is released form the AGM and is converted to water vapor by absorbing heat, thus storing heat energy as latent heat of vaporization in the water vapor. Additionally, a portion of the stored water may be utilized to maintain the activated carbon moisture level. By storing excess water in the AGM instead of the interstitial particle void volume, the exothermic composition in the heat cell is able to rapidly oxidize the iron and generate an internal temperature high enough to produce water vapor generated from the water stored in the AGM. Because of the AGM's high water holding capacity, the exothermic composition in the heat cells remains highly reactive over a sustained period of time. While not wishing to be bound by any theory, it is believed that the AGM may prevent or inhibit liquid water from entering and/or being maintained in the interstitial voids of particulate exothermic compounds thereby facilitating prevention of flooding of the exothermic composition.
Non-limiting examples of suitable absorbent gelling materials include those absorbent gelling materials that have fluid-absorbing properties and can form hydrogels upon contact with water. An example of such an absorbent gelling material is the hydrogel-forming, absorbent gelling material that is based on a polyacid, for example polyacrylic acid. Hydrogel-forming polymeric materials of this type are those which, upon contact with liquids such as water, imbibe such fluids and thereby form the hydrogel. These particularly useful absorbent gelling materials generally comprise substantially water-insoluble, slightly cross-linked, partially neutralized, hydrogel-forming polymer materials prepared from polymerizable, unsaturated, acid-containing monomers. In such materials, the polymeric component formed from unsaturated, acid-containing monomers can comprise the entire gelling agent or can be grafted onto other types of polymer moieties such as starch or cellulose. Acrylic acid grafted starch materials are of this latter type. Thus, specific suitable absorbent gelling materials include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, polyacrylate, maleic anhydride-based copolymer, and combinations thereof. The polyacrylates and acrylic acid grafted starch materials are particularly useful. Non-limiting examples of commercially available polyacrylates include those polyacrylates which are available from Nippon Shokubai located in Chatanooga, Tenn., USA.
The absorbent gelling material has a median particle size of from about 300 μm to about 800 μm, alternatively from about 400 μm to about 800 μm, and alternatively from about 500 μm to about 800 μm. Absorbent gelling materials having a median particle size of 300 μm or greater have been shown to contribute to minimal or no particle segregation effects. Reducing segregation effects provides for improved sustained temperature such that the desired heat benefits are achieved without adverse events such as skin and/or hair burns. Reducing segregation effects also allows for the high-speed production of portable moist heat delivery devices comprising a plurality of heat cells and that provide for up to four or five hours of moist heat.
As described above, the particulate exothermic compositions defined herein have particular median particle size ratios of absorbent gelling material to iron powder. It has been found that exothermic compositions comprising the defined select median particle size ratios of these components exhibit minimal or no segregation effects which result in exothermic compositions that meet the intended thermal behavior for the desired moist heat benefits.
In addition to the absorbent gelling material, the particulate exothermic compositions of the present invention can optionally comprise other water-holding materials that have capillary function and/or hydrophilic properties. These optional water-holding materials can be included in the particulate exothermic compositions at concentrations ranging from about 0.1% to about 25%, alternatively from about 0.5% to about 20%, and alternatively from about 1% to about 15%, by weight of the composition. Non-limiting examples of such optional water-holding materials include vermiculite, porous silicates, wood powder, wood flour, cotton, paper, vegetable matter, carboxymethylcellulose salts, inorganic salts, and combinations thereof. Absorbent gelling material and optional water-holding materials are further described in U.S. Pat. Nos. 5,918,590 and 5,984,995.
The particulate exothermic composition of the present invention comprises one or more metal salts at concentrations ranging from about 0.5% to about 10%, alternatively from about 0.5% to about 7%, and alternatively from about 1% to about 5%, by weight of the composition.
Non-limiting examples of metal salts suitable for use herein include those metal salts that serve as a reaction promoter for activating the surface of the iron powder to ease the oxidation reaction with air and provide electrical conduction to the exothermic composition to sustain the corrosive (i.e., oxidative) reaction. In general, several suitable alkali, alkaline earth, and transition metal salts exist which can be used, alone or in combination, to sustain the corrosive reaction of iron.
Non-limiting examples of suitable metal salts include sulfates, chlorides, carbonate salts, acetate salts, nitrates, nitrites, and combinations thereof. Specific non-limiting examples of sulfates include ferric sulfate, potassium sulfate, sodium sulfate, manganese sulfate, magnesium sulfate, and combinations thereof. Specific non-limiting examples of chlorides include cupric chloride, potassium chloride, sodium chloride, calcium chloride, manganese chloride, magnesium chloride cuprous chloride, and combinations thereof. Cupric chloride, sodium chloride, and mixtures thereof are particularly useful metal salts. An example of a commercially available sodium chloride includes the sodium chloride available from Morton Salt located in Chicago, Ill. (USA).
The particulate exothermic compositions of the present invention comprise water at concentrations ranging from about 1% to about 50%, alternatively from about 1% to about 35%, and alternatively from about 5% to about 33%, by weight of the composition. Water suitable for use herein can be from any appropriate source, non-limiting examples of which include tap water, distilled water, deionized water, or any mixture thereof.
It is known that the thermal performance of exothermic heat cells is highly sensitive to moisture level, with small amounts of water providing only short time of reaction and too much water slowing the desired heating rate and/or flooding the heat cell and terminating the reaction In a device that generates moist heat, one challenge is that a supply of water is needed to create the water vapor for the moist heat. It has been found, however, that the particulate exothermic compositions with interstitial spaces formed by selection of size and distribution of particle sizes of iron and AGM of the present invention not only provide heat cells that are highly effective in generating high amounts of water vapor exceeding 0.25 grams of water vapor per cell over the course of the reaction, but also provide heat cells that have fast initial heating times to achieve desired temperatures quickly. This is achieved by incorporating a sufficient weight ratio of water to absorbent gelling material such that the particulate exothermic compositions have high internal water retention (preferably with the AGM acting as the principal repository) and high interstitial particle void volumes. The particulate exothermic compositions of the present invention comprise a weight ratio of water to absorbent gelling material of from about 3:1 to about 9:1, and alternatively from about 4:1 to about 7:1, by weight of the exothermic composition.
The particulate exothermic compositions of the present invention can comprise a high level of water and yet be constructed at lower cell weight levels than current heat cells. Therefore, the exothermic compositions of the present invention are utilized more effectively with high water concentration, and less exothermic composition is needed to achieve the desired amount and duration of water vapor generation.
The exothermic compositions of the present invention can further comprise one or more optional components known or otherwise effective for use in exothermic compositions, provided that the optional components are physically and chemically compatible with the compositional components described hereinabove, or do not otherwise unduly impair product stability, aesthetics, or performance.
Optional components suitable for use herein include materials such as agglomeration aids for agglomeration of particles, non-limiting examples of which include corn syrup, maltitol syrup, crystallizing sorbitol syrup, and amorphous sorbitol syrup; dry binders, non-limiting examples of which include microcrystalline cellulose, microfine cellulose, maltodextrin, sprayed lactose, co-crystallized sucrose and dextrin, modified dextrose, mannitol, pre-gelatinized starch, dicalcium phosphate, and calcium carbonate; oxidation reaction enhancers non-limiting examples of which include elemental chromium, manganese, copper, and compounds comprising said elements; hydrogen gas inhibitors, non-limiting examples of which include inorganic and organic alkali compounds, and alkali weak acid salts, specific non-limiting examples of which include sodium thiosulfate, sodium sulfite, sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate, calcium hydroxide, calcium carbonate, and sodium propionate; fillers non-limiting examples of which include natural cellulosic fragments including wood dust, cotton linter, and cellulose, synthetic fibers in fragmentary form including polyester fibers, foamed synthetic resins such as foamed polystyrene and polyurethane, inorganic compounds including silica powder, porous silica gel, sodium sulfate, barium sulfate, iron oxides, and alumina; anti-caking agents non-limiting examples of which include tricalcium phosphate and sodium silicoaluminate; and mixtures thereof.
Such components also include thickeners, non-limiting examples of which include cornstarch, potato starch, carboxymethylcellulose, and alpha-starch; and surfactants non-limiting examples of which include anionic, cationic, nonionic, zwitterionic, and amphoteric surfactants. Still other optional components can be included within the compositions or systems herein, as appropriate, including extending agents, non-limiting examples of which include metasilicates, zirconium, and ceramics, and mixtures thereof. The optional components can be included in the particulate exothermic compositions at concentrations ranging from about 0.01% to about 35%, and alternatively from about 0.1% to about 30%, by weight of the composition.
Oxygen is necessary for the oxidation reaction to occur. However, in the exemplary embodiments presented herein an internal oxygen source is not required. Optionally, in other embodiments within the scope of the moist heat delivery systems, an oxygen-producing chemical material may be incorporated in the particulate exothermic composition at the time of preparation thereof. Non-limiting examples of oxygen sources suitable for use with the present invention include air and artificially made oxygen of various purity. Air is particularly useful because it is convenient and inexpensive.
The heat cells of the water vapor generating portion of the present invention can comprise particulate exothermic compositions that utilize an exothermic iron oxidation reaction system to provide a water vapor source. A heat cell comprised of a particulate exothermic composition and used as a water vapor source to deliver moist heat should have a particulate exothermic composition capable of remaining highly reactive even with high water content. High water content provides high rate of water vapor generation for an extended period of time. The particulate exothermic composition provides rapid water vapor generation at temperatures safe for contact with human skin and/or hair when the heat cells are incorporated into a water vapor generating portion of portable moist heat delivery systems. The water vapor generation portion is in communication with the water vapor-air regulation portion, which adjusts the dew point of the water vapor to a pre-selected temperature (i.e., one that will not burn hair or skin) by regulating the proportion of water vapor and air in the water vapor-air mixture.
The exothermic compositions of the present invention are particulate exothermic compositions. As used herein “particulate” refers to separate particles contained within the compositions. The particulate exothermic compositions defined herein contain separate particles wherein each particle has a median particle size ranging from about 25 μm to about 800 μm. In certain embodiments, a range of particles sizes may be preferred to yield a composition with desired interstitial pore space.
In an exemplary embodiment, an exothermic composition is prepared by preparing a premix of wetted carbon, iron, and AGM, which is subsequently treated with a brine solution. According to one embodiment, the compositions may comprise from about 10% to about 90% by weight of iron powder; from about 1% to about 25% by weight of a carbon selected from activated, non-activated carbon and mixtures thereof; from about 1% to about 25% or alternatively about 2% to about 12% by weight of an AGM; and from about 1% to about 50%, alternatively from about 1% to about 35%, or from about 15% to about 35% by weight of water. One exemplary single heat cell of the present invention can comprise from about 0.4 g of pre-mix per cell to about 2.5 g of pre-mix per cell, and from about 0.4 g of brine solution per cell to about 1.5 g of brine solution per cell. A heat cell of the present invention can comprise a total cell weight, per cell, of from about 0.8 g to about 10.0 g, alternatively from about 1.5 g to about 3.5 g, and alternatively from about 2.5 g, to about 3.0 g. In certain embodiments of the moist heat delivery system, a plurality of heat cells may be used in the system.
As described above, selection of the particle size of the particulate components, e.g., the iron and AGM, of exothermic compositions may be important for minimization of particle separation or segregation within an exothermic composition. Particle size directly effects particle mobility and particulate components can vary in their mobility resulting in particle separation or segregation. The exothermic compositions defined herein preferably comprise particulate components having defined median particle size ranges such that the exothermic compositions resist particle separation or segregation. It is contemplated, however that particulate components having median particle sizes ranges above or below the ranges defined herein are suitable for use in the exothermic compositions defined herein.
The heat cells of the present invention are small compared to most conventional commercial heat cells, and excess levels of exothermic composition cannot be used to compensate for particle segregation effects. As described above, particle segregation effects are reduced in the particulate exothermic composition of the present invention by using iron powder in a particular ratio with absorbent gelling material. Without being bound by theory, it is believed that the oxidative reaction rate of such exothermic compositions is controlled by the porosity of the exothermic composition. The accessibility of oxygen through the particulate exothermic composition is affected by the packing behavior of the particles, i.e. the interstitial void volume, and by the amount of water present in the exothermic composition.
In one exemplary embodiment, the heat cell is formed in a unified structure comprising at least two opposed surfaces, preferably, one substantially non-air-permeable and non-moisture-permeable surface, such as a film layer substrate material and one aerated hair-facing surface that is highly air-permeable and moisture-permeable, such as a polymer non-woven material. To direct moist heat toward the hair, the air and moisture permeable side of the heat cell is disposed toward the latent heat delivery surface and hair-facing side of the moist heat delivery system. In one embodiment, the air and moisture permeable surface may be interposed between the heat cell and the water vapor-air regulating portion of the moist heat delivery system and the water vapor-air regulating portion may be interposed between the heat cell and the latent heat transfer surface/hair facing surface. The substantially non-air-permeable surface may either be the external surface or oriented proximate the external surface.
Uniform heating and water vapor generation may be provided by using a plurality of heat cells. By using a plurality of heat cells, the size of an individual heat cell can be reduced. The relatively small size of the heat cells, and their spacing in the system of the present invention enable even air flow to the heat cells. In addition, the water vapor generated can be controlled by the number of heat cells used, and their spacing. By way of non-limiting example, in one embodiment two portable moist heat delivery systems of the same size and composition (i.e., the same in all respects except number of heat cells and the spacing between the heat cells), a system made with 24 heat cells has a water vapor generation rate that is less than two times the water vapor generation rate of a system made with 12 heat cells, yet lasts four times as long. Without being bound by theory, the non-linear water vapor generation and duration relationship is believed to be due to the fixed surface area of the system that is accessible to air. Thus, reaction rate, water vapor generation rate and duration of heat generation can be controlled by the number of heat cells used and their spacing.
The aerated hair-facing surface of the heat cells (e.g., “aerated heat cell surface”) can serve a dual function providing air to the particulate exothermic composition in the water vapor generating portion and preventing the particulate exothermic composition from leaking out of the heat cell, as well as forming a water vapor-air mixing layer as part of the water vapor-air regulating portion. The aerated hair-facing surface impacts regulation of mixing of water vapor and air, particularly when the system is used in a vertical orientation. Variation of the aerated hair-facing surface can thus be used to regulate the amount of air mixed with the generated water vapor to help lower the dew point temperature of the water vapor-air mixture. However, because of its high air permeability the aerated hair-facing surface has no limiting effect on the reaction rate, and particularly the water vapor generation rate, of the system.
The aerated surface of the heat cell facing the hair can be formed of an SMMS (spunbond-meltblown-meltblown-spunbond) material, a SMS (spunbond-meltblown-spunbond) material, a spun-bond material, a melt-blown material, mesh, woven fabric and combinations thereof that can vary in basis weight from about 15 gsm (grams per square meter) to about 90 gsm, and alternatively from about 15 gsm to about 76 gsm. In an SMMS material, the “S” layers in the structure provide strength and air entry, while the two “M” layers are made of much finer denier filaments that function to prevent the smaller carbon particles from leaking out of the cells. Non-limiting examples of suitable materials used for an SMMS layer include polypropylene, polyethylene, polyester or other suitable polymer materials known to those skilled in the art.
The aerated surface of the heat cell facing the hair can have an air-permeability of greater than about 25 cm3/cm2/sec and can have a moisture vapor transmission rate greater than about 5,000 g/m2/24 hr. The aerated surface can have a thickness of from about 0.05 mm to about 1 mm, alternatively from about 0.1 mm to about 0.8 mm, and alternatively of about 0.4 mm
The opposed, non-air- or semi-air-permeable/non-moisture- or semi-moisture-permeable surface of the heat cell can be made of films or films laminated to non-woven fabrics to form a film layer substrate. In general, suitable films are those having heat sealability and are capable of being easily thermally fused. Non-woven materials, if used, provide support and integrity to the film layer substrates. Non-limiting examples of suitable films include polyethylene, polypropylene, nylon, polyester, polyvinyl chloride, vinylidene chloride, polyvinylidene chloride, polyurethane, polystyrene, saponified ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, natural rubber, reclaimed rubber, and synthetic rubber, and combinations thereof. The film layer substrate has a thickness in the range of about 1 μm to about 300 μm and may be non-air- or semi-air-permeable and non-moisture- or semi-moisture-permeable. For non-woven fabric, if used, those having preferred characteristic properties of light weight and high tensile strength, e.g., nylon, rayon, cellulose ester, polyvinyl derivatives, polyolefins, polyamides, or polyesters, are suitable.
A non-limiting example of a preferred non-woven material is a SMMS laminated structure of from about 15 gsm to about 100 gsm (grams per square meter) basis weight, in specific embodiments with a meltblown layer of basis weight of from about 2 gsm to about 16 gsm, alternatively from about 4 gsm to about 10 gsm and alternatively from about 6 gsm to about 8 gsm. Such non-woven materials are generally described in Riedel “Nonwoven Bonding Methods and Materials”, Nonwoven World, (1987). An example of a commercially available non-woven sheet is material number W502FWH, which is commercially available from PGI (Polymer Group International) located in Waynesboro, Va., USA or FQN (First Quality Nonwoven) located in Haxle Township, Pa., USA.
Non-limiting examples of useful film layer substrates include polypropylene non-woven sheets laminated to a film of poly(ethylene-vinyl acetate) or low-density polyethylene (LDPE) having a thickness of from about 5 μm to about 100 μm. An example of a commercially available polypropylene/ethylene vinyl acetate (PP/EVA) film is material number DH245, which is commercially available from Clopay Plastics of Cincinnati, Ohio U.S.A.
The heat cell may be formed by bonding opposed surfaces of the aerated surface material and the non/semi-permeable film together around their periphery thereby forming a pouch, envelope, or pocket. Pockets can also be made in the non/semi-air and non/semi-moisture permeable substrate by vacuum, thermoforming, mechanical embossing, vacuum embossing, or other acceptable means. Preferred for use herein is thermoforming which is described in “Thermoforming”, The Wiley Encyclopedia of Packaging Technology, pp. 668-675 (1986), Marilyn Bakker, ed.
When filled with a particulate exothermic composition, each heat cell has a fill volume, void volume, and a cell volume. The fill volume, as used herein, means the volume of the particulate composition in the filled heat cell. The void volume, as used herein, means the volume of the cell left unfilled by the particulate composition in a finished heat cell, measured without differential pressure in the heat cell and without additional stretching or deformation of the substrate materials. The cell volume, as used herein, means the fill volume plus the void volume of the heat cell. The ratio of fill volume to cell volume is from about 0.7 to about 1.0, alternatively from about 0.75 to about 1.0, more alternatively from about 0.8 to about 1.0, alternatively from about 0.85 to about 1.0, and alternatively from about 0.9 to about 1.0.
A heat cell can also be measured in terms of its height or thickness of the heat cell at the point of greatest thickness. In an exemplary embodiment, the thickness of a heat cell at the point of greatest thickness may be from greater than about 0.2 cm (centimeters) to about 1.0 cm, preferably from greater than about 0.3 cm to about 0.9 cm, alternatively from about 0.4 cm to about 0.8 cm, and alternatively from about 0.5 cm to about 0.7 cm.
The resulting heat cell can have any geometric shape, e.g., disk, triangle, pyramid, cone, sphere, square, cube, rectangle, rectangular parallelepiped, cylinder, ellipsoid and the like. The shape of the heat cell can be elongated in its geometry, with the long axis parallel to the substrates, having a height of from about 0.2 cm to about 5 cm, alternatively from greater than about 0.5 cm to about 1 cm, a width of from about 0.2 cm to about 20 cm, alternatively from about 5 cm to about 10 cm, and a length of from about 1 cm to about 20 cm, alternatively from about 5 cm to about 10 cm, resulting in a cell volume of from about 0.04 cm3 to about 2,000 cm3, or 0.04 cm3 to about 30 cm3 and alternatively from about 1.25 cm3 to about 10 cm3.
Alternatively the shape can be a disk shaped geometry having a cell diameter of from about 0.2 cm to about 5 cm, of from about 1 cm to about 4 cm, alternatively from about 2 cm to about 3 cm, and a height of from about 0.2 cm to about 1 cm, alternatively from about 0.3 cm to about 0.9 cm, alternatively from about 0.4 cm to about 0.8 cm, and alternatively from about 0.5 cm to about 0.7 cm, resulting in a cell volume of from about 0.0045 cm3 to about 20 cm3, alternatively from about 0.2 cm3 to about 1 cm3.
The heat cell can have a planar view surface area, per cell, of from about 0.03 cm2 about 20 cm2, alternatively from about 0.1 cm2 to about 20 cm2, and alternatively from about 1 cm2 to about 20 cm2. Heat cells with this area per cell are easily incorporated into flexible devices which provide improved conformity with body forms; provide even, uniform heat to a target area; and improve wearer comfort.
The heat cell can have a pre-mix weight of from about 0.4 g of pre-mix per cell to about 2.5 g of pre-mix per cell, alternatively from about 1.0 g of pre-mix per cell to about 2.4 g of pre-mix per cell, and alternatively from about 1.5 g of pre-mix per cell to about 2.3 g of pre-mix per cell. Heat cells with this weight of pre-mix per cell are also easily incorporated into flexible devices and systems which provide improved conformity with body forms; provide even, uniform heat to a target area; and improve wearer comfort.
In one exemplary embodiment of the moist heat system, a plurality of heat cells are used. All of the heat cells may be moist heat generators or a component of a moist heat generator, or alternatively a portion of the heat cells may be moist heat generators or component of moist heat generators used in combination with dry heat cells.
According to an exemplary moist heat wrap comprising one or more moist heat delivery systems in which the water vapor source is incorporated into heat cells, the water vapor source may comprise a planar area from about 25% to about 90%, alternatively from about 25% to about 75%, and alternatively from about 25% to about 60% of the total planar area of the water vapor generating portion.
The moist heat delivery system of the present invention contains a water vapor generating portion as described above. The water vapor generating portion preferably selectively directs water vapor toward the water vapor-air regulating portion. As described herein, in one exemplary embodiment this may be accomplished using a permeable film on one side of the water vapor generating device and an impermeable film on the other side of the water vapor generating devise. The water vapor-air regulator portion provides for adjustment of dew point temperature. The water vapor generating portion is in fluid communication with the water vapor-air regulating portion and reduces the dew point temperature of the water vapor-air mixture exiting the system to a safe temperature for delivery of latent heat to the hair of the user. Optionally, the water vapor-air regulating portion may orient water vapor generated by the water vapor generation portion towards the latent heat delivery surface and ultimately a user's body or hair to provide a comfortable device that can he held against the hair, held near the hair with a controlled and pre-selected amount of gap between the surface and the hair, adhesively adhered to the hair, or placed in a holder, such as, for example, a reusable fabric pocket, a wrap, or a contoured device that is held in place at least partially by conforming to a body surface, such as the head, and that holds the water vapor generation portion and/or water vapor-air regulating portion in place against the desired body part. In one exemplary embodiment, the water vapor-air regulating portion or, alternatively, a portion of the water vapor-air regulating portion may be included in the structure of the holder. The holder may be a single use, disposable holder or a multi use, reusable holder. The holder may be held in place by any of a variety of means known in the art including, but not limited to, adhesives, fasteners, ties, interlocking parts, buttons, snaps, or combinations thereof.
According to one exemplary embodiment, the water vapor-air regulating portion can comprise at least one water vapor-air mixing layer and at least one water vapor-air distribution layer. The layers are arranged such that water vapor and air can pass among and between the layers and the water vapor generating portion. The water vapor-air regulating portion can facilitate an even flow of air into, and water vapor out of, the water vapor generating portion, particularly when the system is used in a manner that compresses the system. To minimize the effect of compression, it may be desirable to use a water vapor mixing layer that is resistant to compression. One example of such a material is a needle punched non-woven material. The water vapor-air regulating portion can also comprise one or more latent heat transfer surfaces and/or hair contact layers. The latent heat transfer surface/hair contact layer may be a surface of a portion of the water vapor-air regulating portion or, alternatively, a layer or layers of material.
According to one embodiment, the air permeability of the water vapor-air regulating portion comprising the water vapor-air mixing layer, the water vapor-air distribution layer and latent heat delivery surface and optional hair contact layer is from about 25 cm3/cm2/sec to about 8000 cm3/cm2/sec, alternatively from about 300 cm3/cm2/sec to about 8000 cm3/cm2/sec, and alternatively from about 500 cm3/cm2/sec to about 7000 cm3/cm2/sec, measured using ASTM Method No. D737. According to another embodiment, the air permeability of the water vapor-air regulating portion comprising the water vapor-air mixing layer, the water vapor-air distribution layer and latent heat delivery surface and optional hair contact layer is from about 25 cm3/cm2/sec to about 100 cm3/cm2/sec, alternatively from about 30 cm3/cm2/sec to about 70 cm3/cm2/sec, alternatively from about 40 cm3/cm2/sec to about 60 cm3/cm2/sec, and alternatively about 50 cm3/cm2/sec, measured using ASTM Method No. D737. Appropriate air permeability may depend, for example on the use of the moist heat delivery system, such as for delivery of hair care actives. The moisture vapor transmission rate of the water vapor-air regulating portion is from about 500 g/m2/24 hr to about 2,500 g/m2/24 hr, alternatively from about 1,000 g/m2/24 hr to about 2,000 g/m2/24 hr, and particularly greater than about 1400 g/m2/24 hr, as measured using ASTM Method No. E96. In one exemplary embodiment, the water vapor-air regulating portion may comprise one or more water vapor-air mixing layers and one or more water vapor-air distribution layers.
In one exemplary embodiment, a particularly useful arrangement is to use a single water vapor air distribution layer and a single water vapor-air mixing layer. In this embodiment the moist heat system is incorporated into a moist heat wrap and/or pack. It is critical that the perimeter of the moist heat wrap or pack is heat sealed so that the perimeter of the single water vapor air distribution layer and the single water vapor-air mixing layer of the moist heat system are sealed within the perimeter of the moist heat wrap pack. In a preferred embodiment, the water-vapor air distribution layer may be constructed of a foam material in which the base material of the foam is substantially impermeable to air and water vapor but which has channels and/or apertures which allow passage of air and/or water vapor. The water vapor air distribution layer comprising a perforated foam layer heat sealed around the perimeter restricts air from coming into the perimeter of the moist heat wrap. As a result, the size and number apertures and/or channels in the water vapor distribution layer acts to regulate the system by allowing sufficient air for generating the water vapor while also allowing the exiting water vapor to easily move out of the wrap toward the hair, thus regulating the reaction rate and in turn the amount of water vapor generated. By regulating the amount of water vapor generated, the water vapor regulating portion of the device can be simplified. Moreover, for embodiments using thermal cells, regulation of the amount of air for reaction may also facilitate the control of the heating of the heat cells so that the cells do not reach an excessively high temperature. In one exemplary embodiment, a single layer of 0.8 mm ( 1/32 inch) foam may be sufficient to allow for both good moist heat production and transfer performance and for safe handling of a replaceable moist heat pack with the hands for removal of the pack from air tight packaging, which initiates activation, and installation into a reusable heat wrap or holder. A thin moist heat pack that is convenient to handle is desirable for use in a semi-durable moist heat wrap or other semi-durable moist heat device, since it allows for safe handling of the disposable moist heat pack and convenient reuse of at least a portion of the wrap.
In certain embodiments, for constructing the water vapor-air regulating portion, one or more water vapor-air mixing layers may be used, one or more water vapor-air distribution layers may be used, and one or more hair contact layers may be used. In one exemplary embodiment, a particularly useful arrangement is to use two water vapor-air mixing layers and two water vapor-air distribution layers, alternating between the two, with the first water vapor-air mixing layer adjacent the water vapor generating portion. Alternatively a water vapor-air distribution layer can be placed adjacent the water vapor generating portion. Alternatively, as described above, a water vapor air mixing layer can also be physically formed in integral association with the water vapor generating portion.
The system of the present invention is designed to allow an exothermic water vapor source to operate at a high temperature, from about 50° C. to about 70° C., to maximize water vapor production while delivering latent heat and moisture to the user at a pre-selected temperature that does not harm/burn the hair or skin. As water vapor and the condensation of water vapor to release latent heat are important to the energy transfer in a moist heat system, the pre-selected temperature for the moist heat system in a preferred embodiment is the dew point temperature of the water vapor-air mixture proximate the latent heat transfer surface and/or hair contact layer. Thus, the system provides both protection from thermal damage to the user and maintains an ideal water vapor generating environment that stores and subsequently releases heat energy at the desired location.
The inventors have surprisingly discovered that dew point temperatures higher than about 43° C. may be used in certain instances without harming the hair or skin. Without being held to any theory, it is believed that this is because sufficient latent heat energy delivered to the hair and skin may stimulate circulation and facilitate dissipation of the heat energy to avoid harm. Alternatively, the design of the device may modify the contact time of the water vapor with the hair and skin such that the contact time is insufficient to condense all of the water vapor; hence reducing the energy transfer to the skin and hair.
In one embodiment, the water vapor is made safe for skin and/or hair contact by regulating the mixture of water vapor and air to a water vapor to dry air ratio of less than about 0.065 kg water/kg dry air. By regulating the ratio of water vapor to air, the water vapor in the water vapor-air mixture will condense at a dew point temperature such that heat can be optimally and safely transferred to a user's skin and/or hair without the risk of thermal injury. As used herein, “dry air” refers to air with no appreciable water content.
Although the descriptions herein include one exemplary embodiment using two pairs of water vapor-air mixing layers and two pairs of water vapor-air distribution layers, one skilled in the art will appreciate that the same effects could be achieved with one, two, or more water vapor-air mixing layers and/or one, two, or more water vapor-air distribution layers, or some combination thereof may also be used in the device. Adjustment of the location, thickness, air permeability, and moisture vapor transmission rate of each layer and/or type of material may be desirable to create a suitable thermal and air mixing environment, for example in those embodiments having a plurality of mixing layers and/or distribution layers.
In one exemplary embodiment, the ratio of water vapor to dry air can be regulated by utilizing one or more longitudinal strips, as described below, disposed parallel to a row of multiple heat cells. In one embodiment, one water vapor-air mixing layer can be used in combination with longitudinal strips of foam positioned at the hair-facing side of the water vapor-air mixing layer. The strip(s) may function as a portion of the water vapor-air regulating portion. The longitudinal strips can serve to create an air space parallel to a row of multiple heat cells. The air space can aid in providing even flow of air into the water vapor generating portion, and aid in water vapor-air mixing. The height of the longitudinal strips can be adjusted such that the ratio of water vapor to dry air is less than 0.065 kg water/kg of dry air, and alternatively less than about 0.060 kg water/kg dry air. Without wishing to be held to any theory, it is believed that one or more strip over a plurality of heat cells may enable the plurality of heat cells covered by the strip(s) to act and/or be impacted cooperatively. In specific embodiments, it may not be necessary that all heat cells be grouped and/or aligned in rows and covered by a strip. In certain embodiments, only one row or group or a portion of the rows or groupings of heat cells may be covered with a strip.
In one exemplary embodiment, at least one water vapor-air mixing layer can comprise an aerated structure of between about 18 gsm to about 430 gsm (grams per square meter), or from about 50 gsm to a bout 150 gsm, or even about 50 gsm and about 100 gsm, and alternatively about 70 gsm to about 90 gsm. The at least one water vapor-air mixing layer can have a caliper-measured thickness according to ASTM Method No. D5729 of from about 1 mm to about 19 mm, alternatively from about 1 mm to about 5 mm, alternatively from about 0.1 mm to about 4 mm or from about 1 mm to about 4 mm, and particularly of about 3 mm. Non-limiting examples of materials suitable for the water vapor-air mixing layer include woven materials; non-woven materials including wet-laid, air-laid, point-bonded, needle-punched and thermally bonded non-woven materials; fabrics; polyethylene; polypropylene; polyester; wood pulp; rayon; fibrous plant-based materials including celluloses, wool, silk, jute, hemp, cotton, linen, sisal, ramie; and combinations thereof.
The at least one water vapor-air mixing layer has an air permeability of from about 400 cm3/cm2/sec to about 17,000 cm3/cm2/sec, or even from about 500 cm3/cm2/sec to about 2,000 cm3/cm2/sec, and alternatively from about 1,000 cm3/cm2/sec to about 1,500 cm3/cm2/sec, as measured by ASTM Method No. D737, and a moisture vapor transmission rate of from about 5,000 g/m2/24 hr to about 7,000 g/m2/24 hr, and alternatively from about 5,500 g/m2/24 hr to about 6,500 g/m2/24 hr, as measured by ASTM Method E96.
In one exemplary embodiment, at least one water vapor-air distribution layer can comprise a layer of insulative material having a caliper-measured thickness, according to ASTM Method No. D5729, of from about 0.1 mm to about 13 mm, alternatively from about 0.5 mm to about 6 mm, and alternatively from about 1 mm to about 2 mm. In another embodiment, the layer of insulative material may have a caliper-measured thickness of from about 0.1 mm to about 3 mm, alternatively from about 0.5 mm to about 2 mm, and particularly about 1 mm. In one embodiment, the at least one water vapor-air distribution layer can have a basis weight of from about 5 gsm to about 430 gsm, alternatively from about 5 gsm to about 50 gsm, and alternatively from about 5 gsm to about 25 gsm, as measured by ASTM Method No. D3776. In another embodiment, the at least one water vapor-air distribution layer can have a basis weight of from about 5 gsm to about 30 gsm, alternatively from about 7 gsm to about 12 gsm, and particularly about 10 gsm, as measured by ASTM Method No. D3776. The material of the water vapor-air distribution layer is substantially air and moisture impermeable, and can be resistant to compression.
Non-limiting examples of materials suitable for the water vapor-air distribution layer include polyethylene-based foam, polypropylene-based foam, polyester-based foam, polystyrene-based foam, polyurethane-based foam, foamed plastic sheet, plastic film, foil, paper-foil laminate, paper, non-woven, sponge, glass wool, fiberglass, and combinations thereof.
The air and moisture impermeable material can have an air permeability of less than about 0.025 cm3/cm2/sec, measured using ASTM Method No. D737, and a moisture vapor transmission rate of less than about 200 g/m2/24 hr as measured using ASTM Method No. E96.
In one embodiment, the material can also have a thermal conductivity of from about 0.5 W/m*K to about 285 W/m*K (K=degrees Kelvin) and a density of from about 5 kg/m3 to about 150 kg/m3. In another embodiment, the material can also have a thermal conductivity of from about 0.25 W/m*K to about 0.5 W/m*K (K=degrees Kelvin) and a density of from about 5 kg/m3 to about 15 kg/m3. Thermal conductivity of this material can be obtained from the following source: “For Computer Heat-Conduction Properties data” A. L. Edwards, UCRL-505 Copyright K&K Associates 1997.
In certain embodiments, it may be desirable to selectively perforate the air and moisture impermeable material to form the water vapor-air distribution layer and allow passage of air and water vapor through to the user, and to allow air to enter and to reach the water vapor generating portion, particularly if an exothermic oxidation reaction is used as the mechanism for water vapor generation. Alternatively, apertures and/or channels may be employed to allow passage of air and water vapor-air mixtures. While the materials used for the water vapor-air distribution layer may be substantially impermeable to air and water vapor, they should be assembled, constructed or configured such that the overall air permeability of the vapor-air distribution layer is for one embodiments from about 500 cm3/cm2/sec to about 2500 cm3/cm2/sec, alternatively about 1000 cm3/cm2/sec to about 2500 cm3/cm2/sec, and alternatively about 1500 cm3/cm2/sec to about 2300 cm3/cm2/sec as measured by ASTM Method D737. In another embodiment, the overall air permeability may range from about 100 cm3/cm2/sec to about 300 cm3/cm2/sec, alternatively greater than about 150 cm3/cm2/sec and alternatively greater than about 200 cm3/cm2/sec as measured by ASTM Method D737. The moisture vapor transmission rate of the vapor-air distribution layer is from about 6,000 g/m2/24 hr to about 9,000 g/m2/24 hr, alternatively from about 7,000 g/m2/24 hr to about 8,500 g/m2/24 hr, alternatively from about 7,500 g/m2/24 hr to about 8,500 g/m2/24 hr, and preferably about 8,100 g/m2/24 hr as measured by ASTM Method E96.
As described herein, in certain embodiments, the water vapor-air regulating portion can also comprise longitudinal strips. Longitudinal strips can be used to provide additional air to the system for reaction and to provide additional water vapor-air mixing. The longitudinal strips can comprise any flexible and non-compressible material. The height of the longitudinal strips can be adjusted to achieve a desired water vapor to air ratio of less than about 0.085 kg water/kg dry air, or even less than about 0.065 kg water/kg dry air, and alternatively less than about 0.060 kg water/kg dry air. Non-limiting examples of materials suitable for use in the longitudinal strips include polyethylene-based foam, polypropylene-based foam, polystyrene-based foam, polyurethane-based foam, foamed plastic sheet, plastic film, foil, paper-foil laminate, non-wovens, sponge, glass wool, fiberglass, and combinations thereof. The longitudinal strips can be disposed proximate to the latent heat transfer surface at the hair-facing side of the system, whether the system is a single-use disposable system, or whether the system is a reusable system. Optionally, for a reusable system in which a portion of the system may be disposable, the longitudinal strips can be disposed on either the disposable or reusable portion.
In specific embodiments, the latent heat delivery surface is in communication with the water vapor-air regulating portion and abuts or is adjacent to the hair surface or the hair contact layer when the system is in use. The latent heat delivery surface may contact the hair surface or alternatively be positioned with a predetermined gap between the latent heat delivery surface and the hair surface. The latent heat delivery surface may be a surface on a portion of the water vapor-air regulator portion or alternatively a separate layer. In an exemplary embodiment, the latent heat delivery surface may be, for example, a layer of material that has a basis weight of from about 20 gsm to about 100 gsm, alternatively from about 40 gsm to about 90 gsm and particularly from about 80 gsm to about 82 gsm. In an exemplary embodiment the latent heat delivery surface may have, for example, a caliper-measured thickness of from about 0.05 mm to about 12 mm, and alternatively from about 0.1 mm to about 5.0 mm, and alternatively from about 0.2 mm to about 2 mm. The latent heat surface can have an air permeability of from about 200 cm3/cm2/sec to about 500 cm3/cm2/sec, alternatively from about 300 cm3/cm2/sec to about 400 cm3/cm2/sec, and particularly about 314 cm3/cm2/sec measured using ASTM Method No. D737. The latent heat surface can have a moisture vapor transmission rate of greater than about 5,000 g/m2/24 hr measured using ASTM Method No. E96.
Non-limiting examples of suitable materials for the latent heat delivery surface include nylon, rayon, cellulose ester, polyvinyl derivatives, polyolefins, polyamides, polyesters, polypropylenes, celluloses, wool, silk, jute, hemp, cotton, linen, sisal, ramie, and combinations thereof.
Optionally at least one hair contact layer can be added at the hair-facing side of the system, such as at the latent heat delivery surface. Such a material has a basis weight of from about 20 gsm to about 100 gsm, alternatively from about 40 gsm to about 90 gsm and particularly from about 80 gsm to about 82 gsm. The hair contact layer has a caliper-measured thickness of from about 0.05 mm to about 12 mm, and alternatively from about 0.1 mm to about 5.0 mm, and alternatively from about 0.2 mm to about 2 mm. The hair contact layer(s) can have an air permeability of from about 200 cm3/cm2/sec to about 500 cm3/cm2/sec, alternatively from about 300 cm3/cm2/sec to about 400 cm3/cm2/sec, and particularly about 314 cm3/cm2/sec measured using ASTM Method No. D737. The hair contact layer(s) can have a moisture vapor transmission rate of greater than about 5,000 g/m2/24 hr measured using ASTM Method No. E96.
Non-limiting examples of suitable materials for the hair contact layer include nylon, rayon, cellulose ester, polyvinyl derivatives, polyolefins, polyamides, polyesters, polypropylenes, celluloses, wool, silk, jute, hemp, cotton, linen, sisal, ramie, and combinations thereof.
In specific embodiments, it may be preferable that the exterior surface layer (i.e., non-hair facing side) of the system opposing the latent heat delivery surface and the hair-facing side (i.e. the outer side of the water vapor generating portion or surface furthest from the hair) can comprise an insulative layer that prevents the non-hair facing side of the system from becoming too hot, and that also directs heat downward toward the hair-facing side of the system. The insulative layer can be placed adjacent the opposed side of the heat cells or other water vapor source forming the water vapor generating portion.
Non-limiting examples of materials suitable for an insulative layer include, polyethylene-based foam, polypropylene-based foam, polystyrene-based foam, polyester-based foam, polyurethane-based foam, foamed plastic sheet, plastic film, foil, paper-foil laminate, non-wovens, sponge, glass wool, fiberglass, and combinations thereof.
Such an insulative layer can have a caliper-measured thickness, according to ASTM Method No. D5729, of from about 0.1 mm to about 3 mm, alternatively from about 0.5 mm to about 2.5 mm, alternatively from about 1 mm to about 2 mm, and alternatively of about 1 mm.
Such an insulative layer has an air permeability of less than about 0.025 cm3/cm2/sec measured using ASTM Method No. D737, and a moisture vapor transmission rate of less than about 250 g/m2/24 hr measured using ASTM Method No. E96. In one embodiment, the insulative layer may have a thermal conductivity of from about 0.5 W/m*K to about 285 W/m*K and a density of from about 5 kg/m3 to about 150 kg/m3. In another embodiment, the insulative layer may have a thermal conductivity of from about 0.25 W/m*K to about 0.5 W/m*K and a density of from about 5 kg/m3 to about 15 kg/m3. Thermal conductivity of this material can be obtained from the following source: “For Computer Heat-Conduction Properties data” A. L. Edwards, UCRL-505 Copyright K&K Associates 1997.
An optional one or more outermost layer of material can be added adjacent the insulative layer. Non-limiting examples of such an outermost material include those described above for hair contact layers. The insulative layer and outermost material can also be formed as a pre-combined laminate. Optionally, the one or more outermost layer of material may act as a covering and/or be a part of the structure for holding the device in place during use.
The various layers of the heat generating and/or water vapor-air regulating portion and/or latent heat delivery surface/hair contact layer can be bonded together in any number of ways known to those of skill in the art. Non-limiting examples of suitable attachment methods include heat sealing around the periphery of the layers; hot melt glue or adhesive between each layer; spray-on adhesive; ultrasonic bonding/welding; pressure bonding; crimping and combinations thereof. In certain embodiments, it may be desirable to selectively bond only some of the layers.
Optionally, the system of the present invention can also comprise a moldable portion and/or be positioned in a molded structure. The moldable portion can provide additional flexibility and stability for use of the system on portions of the body on which it may be difficult to achieve a good fit, such as the face and/or head.
Non-limiting examples of materials from which the moldable portion can be formed include metal foil, metal wire frame structure, flexible plastic structure, flexible laminate structure, and combinations thereof. Such a moldable portion can be incorporated within the structure of the system, or can be an external structure removably or non-removably attachable to an outer surface.
The wraps, packs or patches comprising moist heat systems may be self-contained or alternatively placed in a holder. A self contained embodiment may be directly attached to the user such as, for example, by an adhesive or by material extensions that form a wrap that can be secured by lapping, tying or fasteners. It should also be understood that the device may be a single use device or a reusable or partially reusable device. For reusable or partially reusable devices, replaceable parts such, as for example, the heat source should be conveniently removable, but securable into position for use.
Suitable materials for holders include, but are not limited to, materials listed as suitable for use for the latent heat delivery surface and/or exterior surface layer.
The particulate exothermic compositions of the present invention can be prepared by any known or otherwise effective technique suitable for providing an exothermic composition that provides a moist heat benefit. The particulate exothermic compositions of the present invention are preferably prepared using conventional blending techniques such as the blending technique described herein. Other suitable methods of blending the components of the particulate exothermic compositions of the present invention are more fully described in U.S. Pat. No. 4,649,895 to Yasuki et al., issued Mar. 17, 1987.
In a preferred embodiment, a particular technique of blending the components of the particulate exothermic compositions involves adding carbon to a blender or mixer, followed by adding a small amount of the total water, and then mixing the carbon/water combination. Usually enough water is added to assist in blending while avoiding premature exothermic reaction. Mixing is stopped and an absorbent gelling material is added to the carbon/water combination. Mixing is resumed until all the components are mixed thoroughly, and then iron powder is added and mixed. The composition is then blended until thoroughly mixed to form a particulate premix. Sodium chloride, optionally a hydrogen gas inhibitor such as sodium thiosulfate, and the remaining water are separately mixed to form a brine solution which is then added to the iron powder premix to form a particulate exothermic composition that is useful in the construction of a heat cell of the present invention.
In one exemplary embodiment, heat cells having two opposed surfaces can be prepared by adding a fixed amount of the particulate premix composition to a pocket in a film layer substrate sheet such as a pocket in a polypropylene/poly(ethylene-vinyl acetate)(EVA) coextruded film layer substrate sheet. In this process, water or brine is rapidly dosed on top of the premix composition, and an aerated structure such as formed of a polypropylene SMMS non-woven substrate is placed over the cell, as an opposing surface, facing the EVA film side of the preformed pocket-containing sheet. The film layer and non-woven layer are bonded together using a low heat, forming a unified structure. The resulting heat cell contains the particulate exothermic composition sealed in the pocket between the film layer and aerated structure.
It has been found that heat cells prepared by the method described herein are especially effective in providing high water vapor generation initially and throughout the desired heat treatment, provided that the heat cells comprise an exothermic composition comprising a select median particle size ratio of absorbent gelling material to iron powder defined herein.
Alternatively, individual heat cells can be prepared by using vacuum to form a pocket. That is, vacuum is used to draw the film layer substrate surface into a mold as the particulate premix composition is placed on top of the film layer substrate surface directly over the mold. The particulate premix composition drops into the vacuum formed pocket which is held in place by the vacuum exerted upon the film in the bottom of the mold. Next, a brine solution is rapidly dosed on top of the premix composition. A hair-facing aerated structure such as an SMMS polypropylene non-woven substrate surface is then placed over the first film layer substrate surface as an opposing surface, such that the particulate exothermic composition is contained between the two opposed surfaces. The particulate exothermic composition is then sealed between the first and second opposed surfaces. Once the heat cells are formed and sealed, the vacuum is released. This particular structure and method of making a plurality of heat cells is particularly advantageous for a moist heat wrap because it eliminates a need to have a separate moisture-impermeable film to keep the generated water vapor directed toward the hair-facing side of the device.
The resultant heat cells can be used individually or as a plurality of heat cells. The heat cells can be incorporated into various portable and disposable heating devices such as disposable and/or reusable hair treatment wraps. Some wraps that can include the systems can have a means for retaining the wraps in place around the head and/or hair. The retaining means can include but are not limited to, adhesives and/or fastening systems such as a re-closable two-part hook and loop fastening system, adhesives, ties, fasteners, and the like.
Alternatively, the water vapor generating portion, for example formed of a plurality of heat cells, can be disposable, and fittable into a re-usable device such that a portion of the device is disposable and a portion reusable. By way of non-limiting example, the water vapor generating portion can be disposable and the water vapor-air regulating portion can be reusable.
The resultant heat cells are packaged within 1 to 5 minutes after dosing with the brine solution in a secondary air-impermeable package to prevent the oxidation reaction from occurring until desired, as described in the aforementioned U.S. Pat. No. 4,649,895. Heat cells can also be packaged at a later time provided they are kept in an environment free from oxygen using means known to those skilled in the art such as nitrogen blanketing.
Additional layers can be added or layers may be modified, as desired for various effects and performance, to the structure on the hair-facing side of the device, the opposing side, or both. Examples include, but are not limited to, a non-woven hair facing layer that can be texturized to impart softness or a layer that can be impregnated with an aroma or hair care active.
By way of non-limiting example, as described below, one or more insulative layers can be added to either the hair-facing side or the opposing side. Alternatively or in addition, various other layers can be added, as described below, to the hair-facing side of the device. The final structure can be sealed around the perimeter through all of the layers with a perimeter seal, or each layer can be sealed to adjacent layers using sealing systems, non-limiting examples of which include spray-on adhesive, ultrasonic bonding, polymer welding systems, hot melt glue or adhesive between each layer, pressure bonding, crimping, and combinations thereof.
In one exemplary embodiment the heat cells may have different heating output. For example, there may be a combination of high moist heat/short time heat cells with lower moist heat/longer time heat cells. Examples of ways in which the duration of heating of a heat cell may be controlled include, but are not limited to, the amount of exothermic particulate composition included in the cell and/or the amount of moisture available for forming water vapor. Another variation may be to use one or more moist heat delivery system thermal cells in combination with one or more conventional conduction thermal cells in a single device.
The system of the present invention can optionally incorporate a composition to be delivered to the skin and/or hair, wherein the optional composition includes aromatic compounds, non-active aromatic compounds, hair care actives, and combinations thereof.
The amounts of such actives can vary, depending on the particular active. However, in certain embodiments, the amounts provided may be less than those required for dosing the hair care active in a dry environment, such as with a dry heat mechanism or no heat mechanism.
The optional composition, such as a hair care active, can be incorporated into the water vapor generating portion as a separate substrate layer, incorporated into at least one of the substrate layers forming the heat cells, incorporated into the chemistry contained in the heat cells, incorporated into separate active-containing cells, or incorporated into a separate, discrete device to be used with the water vapor generating portion and water vapor-air regulating portion. The heat cells can also comprise a separate substrate layer, or be incorporated into at least one of the opposing surfaces, a self-adhesive component and/or a sweat-absorbing component.
The moist heat delivery system is amenable to a wide variety of types of active hair care compositions including, but not limited to, volatile materials, water soluble materials, materials with limited water solubility at ambient temperatures, and combinations thereof. Further, in certain embodiments, water insoluble materials may be utilized in the system, such as, for example, when presented to the system in combination with suitable solvents and/or solubilizers.
Non-limiting examples of active aromatic compounds include menthol, camphor, eucalyptus, and mixtures thereof. Non-limiting examples of non-active aromatic compounds include benzaldehyde, citral, decanal, aldehyde, and combinations thereof.
A hair care composition can be applied prior to, simultaneously with, as a part of, or subsequent to application of the portable moist heat delivery system. In one embodiment i) a hair care composition is applied to the hair, ii) rinsed off, then iii) a second hair care composition is applied to the hair, and iv) a portable moist heat delivery system is applied to the hair. In another embodiment i) a hair care composition is applied to the hair, ii) a portable moist heat delivery system is applied to the hair. In another embodiment i) one hair care composition is applied to the hair, ii) a portable moist heat delivery system is applied to the hair, and iii) a second hair care composition is applied to the hair after the portable moist heat delivery system is removed from the hair. The hair care composition can provide a variety of benefits including, but not limited to, conditioning, shine enhancement, healthier hair, healthier scalp, anti-dandruff, and/or any combination thereof.
In one embodiment the hair composition comprises from about 0.1% to about 10%, by weight, preferably from about 0.1% to about 5%, more preferably from about 0.25% to about 1%, of a monohydric, fatty alcohol having a melting point of 30° C. or lower, said fatty alcohol being preferably selected from the group consisting of unsaturated straight chain fatty alcohols, saturated branched chain fatty alcohols, saturated C8-C12 straight chain alcohols, and mixtures thereof; from about 0.1% to about 10%, by weight, preferably from about 0.2% to about 5%, more preferably from about 0.5% to about 3%, of a polymer of ethylene oxide, propylene oxide, and mixtures thereof, having the general formula:
wherein R is selected from the group consisting of H, methyl, and mixtures thereof; and n has an average value of from about 2,000 to about 14,000, preferably from about 5,000 to about 9,000, more preferably from about 6,000 to about 8,000; from 0% to about 20%, by weight, of one or more conditioning actives selected from the group consisting of cationic surfactants, cationic polymers, nonvolatile silicones, nonvolatile hydrocarbons, saturated C14 to C22 straight chain fatty alcohols, nonvolatile hydrocarbon esters, and mixtures thereof; and from about 50% to about 99.8%, by weight, water.
In another embodiment the hair care composition comprises one or more of the following conditioning actives:
The compositions of the present invention may comprise from about 0.1% to about 10%, by weight, preferably from about 0.1% to about 5%, more preferably from about 0.25% to about 1%, of a nonvolatile low melting point fatty alcohol.
The fatty alcohols hereof have a melting point of 30° C. or less, preferably about 25° C. or less, more preferably about 22° C. or less.
The unsaturated fatty alcohols hereof are also nonvolatile. By nonvolatile what is meant is they have a boiling point at 1.0 atmospheres of at least about 260° C., preferably at least about 275° C., more preferably at least about 300° C.
Suitable fatty alcohols include unsaturated monohydric straight chain fatty alcohols, saturated branched chain fatty alcohols, saturated C8-C12 straight chain fatty alcohols, and mixtures thereof. The unsaturated straight chain fatty alcohols will typically have one degree of unsaturation. Di- and tri- unsaturated alkenyl chains may be present at low levels, preferably less than about 5% by total weight of the unsaturated straight chain fatty alcohol, more preferably less than about 2%, most preferably less than about 1%.
Preferably, the unsaturated straight chain fatty alcohols will have an aliphatic chain size of from C12-C22, more preferably from C12-C18, most preferably from C16-C18. Especially preferred alcohols of this type include oleyl alcohol and palmitoleic alcohol.
The branched chain alcohols will typically have aliphatic chain sizes of from C12-C22, preferably C14-C20, more preferably C16-C18. Exemplary branched chain alcohols for use herein include isostearyl alcohol, octyl dodecanol, and octyl decanol.
Examples of saturated C8-C12 straight chain alcohols include octyl alcohol, caprylic alcohol, decyl alcohol, and lauryl alcohol.
The low melting point fatty alcohols hereof are used at a level of from about 0.1% to about 10%, by weight of the composition, more preferably from about 0.1% to about 5%, most preferably from about 0.25% to about 1%.
In one embodiment of the present invention the composition is limited to levels of monohydric saturated straight chain fatty alcohols, such as cetyl alcohol and stearyl alcohol, and other waxy fatty alcohols having melting points above 45° C., of no more than about 5%, by weight of the composition, preferably no more than about 4% since the presence of such waxy fatty alcohols can adversely affect the shine benefits of the present invention. In another embodiment of the present invention the composition is limited to levels of monohydric saturated straight chain fatty alcohols, such as cetyl alcohol and stearyl alcohol, and other waxy fatty alcohols having melting points above 45° C., of no more than about 0.1% to about 10%, and/or from about 1% to about 8%, by weight of the composition. However, it may be desirable to use waxy fatty alcohols for their conditioning benefits.
The compositions of the present invention comprise from about 0.1% to about 10%, more preferably from about 0.2% to about 5%, and most preferably from about 0.5% to about 3% of a polymer of ethylene oxide and/or propylene oxide.
The polymers of the present invention are characterized by the general formula:
wherein R is selected from the group consisting of H, methyl, and mixtures thereof. When R is H, these materials are polymers of ethylene oxide, which are also known as polyethylene oxides, polyoxyethylenes, and polyethylene glycols.
When R is methyl, these materials are polymers of propylene oxide, which are also known as polypropylene oxides, polyoxypropylenes, and polypropylene glycols. When R is methyl, it is also understood that various positional isomers of the resulting polymers can exist.
In the above structure, n has an average value of from about 2,000 to about 14,000, preferably from about 5,000 to about 9,000, more preferably from about 6,000 to about 8,000. Polyethylene glycol polymers useful herein that are especially preferred are PEG-2M wherein R equals H and n has an average value of about 2,000 (PEG-2M is also known as Polyox WSR® N-10 from Union Carbide and as PEG-2,000); PEG-5M wherein R equals H and n has an average value of about 5,000 (PEG 5-M is also known as Polyox WSR® N-35 and Polyox WSR® N-80, both from Union Carbide and as PEG-5,000 and Polyethylene Glycol 300,000); PEG-7M wherein R equals H and n has an average value of about 7,000 (PEG 7-M is also known as Polyox WSR® N-750 from Union Carbide); PEG-9M wherein R equals H and n has an average value of about 9,000 (PEG 9-M is also known as Polyox WSR® N-3333 from Union Carbide); and PEG-14 M wherein R equals H and n has an average value of about 14,000 (PEG 14-M is also known as Polyox WSR® N-3000 from Union Carbide.)
Other useful polymers include the polypropylene glycols and mixed polyethylene/polypropylene glycols.
All percentages describing the polymers in this section of the description herein, are by weight, unless otherwise specified.
The compositions of the present invention comprise from about 50% to about 99.8%, by weight, water. The water phase can optionally include other liquid, water-miscible or water-soluble solvents such as lower alkyl alcohols, e.g. C1-C5 alkyl monohydric alcohols, preferably C2-C3 alkyl alcohols. However, the liquid fatty alcohol must be miscible in the aqueous phase of the composition. Said fatty alcohol can be naturally miscible in the aqueous phase or can be made miscible through the use of cosolvents or surfactants.
The composition of the present invention is an emulsion, having viscosity at 25° C. of at least about 5,000 cP preferably from about 8,000 cP to about 50,000 cP, more preferably from about 15,000 cP to about 35,000 cP. Viscosity is determined by a Brookfield RVT, at 20 RPM.
The compositions of the present invention preferably have a pH of from about 2.5 to about 7, more preferably from about 3 to about 6.8, most preferably from about 3.5 to about 6.5. Higher pH can be utilized as long as the composition retains a viscosity of at least about 8,000 cP at 25° C.
Cationic surfactants useful in compositions of the present invention, contain amino or quaternary ammonium moieties. The cationic surfactant will preferably, though not necessarily, be insoluble in the compositions hereof. Cationic surfactants among those useful herein are disclosed in the following documents, all incorporated by reference herein: M.C. Publishing Co., McCutcheon's, Detergents & Emulsifiers, (North American edition 1979); Schwartz, et al., Surface Active Agents, Their Chemistry and Technology, New York: Interscience Publishers, 1949; U.S. Pat. No. 3,155,591, Hilfer, issued Nov. 3, 1964; U.S. Pat. No. 3,929,678, Laughlin et al., issued Dec. 30, 1975; U.S. Pat. No. 3,959,461, Bailey et al., issued May 25, 1976; and U.S. Pat. No. 4,387,090, Bolich, Jr., issued Jun. 7, 1983.
Among the quaternary ammonium-containing cationic surfactant materials useful herein are those of the general formula:
wherein R1-R4 are independently an aliphatic group of from about 1 to about 22 carbon atoms or an aromatic, alkoxy, polyoxyalkylene, alkylamido, hydroxyalkyl, aryl or alkylaryl group having from about 1 to about 22 carbon atoms; and X is a salt-forming anion such as those selected from halide, (e.g. chloride, bromide), acetate, citrate, lactate, glycolate, phosphate nitrate, sulfate, and alkylsulfate radicals. The aliphatic groups may contain, in addition to carbon and hydrogen atoms, ether linkages, and other groups such as amino groups. The longer chain aliphatic groups, e.g., those of about 12 carbons, or higher, can be saturated or unsaturated. Especially preferred are di-long chain (e.g., di C12-C22, preferably C16-C18, aliphatic, preferably alkyl) and di-short chain (e.g., C1-C3 alkyl, preferably C1-C2 alkyl) quaternary ammonium salts.
Salts of primary, secondary and tertiary fatty amines are also suitable cationic surfactant materials. The alkyl groups of such amines preferably have from about 12 to about 22 carbon atoms, and may be substituted or unsubstituted. Such amines, useful herein, include stearamido propyl dimethyl amine, diethyl amino ethyl stearamide, dimethyl stearamine, dimethyl soyamine, soyamine, myristyl amine, tridecyl amine, ethyl stearylamine, N-tallowpropane diamine, ethoxylated (with 5 moles of ethylene oxide) stearylamine, dihydroxy ethyl stearylamine, and arachidylbehenylamine. Suitable amine salts include the halogen, acetate, phosphate, nitrate, citrate, lactate, and alkyl sulfate salts. Such salts include stearylamine hydrochloride, soyamine chloride, stearylamine formate, N-tallowpropane diamine dichloride and stearamidopropyl dimethylamine citrate. Cationic amine surfactants included among those useful in the present invention are disclosed in U.S. Pat. No. 4,275,055, Nachtigal, et al., issued Jun. 23, 1981.
Cationic surfactants are preferably utilized at levels of from about 0.1% to about 10%, more preferably from about 0.25% to about 5%, most preferably from about 0.5% to about 2%, by weight of the composition.
The compositions of the present invention can also comprise one or more cationic polymer conditioning actives. The cationic polymer conditioning actives will preferably be water soluble. Cationic polymers are typically used in the same ranges as disclosed above for cationic surfactants.
By “water soluble” cationic polymer, what is meant is a polymer which is sufficiently soluble in water to form a substantially clear solution to the naked eye at a concentration of 0.1% in water (distilled or equivalent) at 25° C. Preferably, the polymer will be sufficiently soluble to form a substantially clear solution at 0.5% concentration, more preferably at 1.0% concentration.
As used herein, the term “polymer” shall include materials whether made by polymerization of one type of monomer or made by two (i.e., copolymers) or more types of monomers.
The cationic polymers hereof will generally have a weight average molecular weight which is at least about 5,000, typically at least about 10,000, and is less than about 10 million. Preferably, the molecular weight is from about 100,000 to about 2 million. The cationic polymers will generally have cationic nitrogen-containing moieties such as quaternary ammonium or cationic amino moieties, and mixtures thereof.
The cationic charge density is preferably at least about 0.1 meq/gram, more preferably at least about 1.5 meq/gram, even more preferably at least abut 1.1 meq/gram, most preferably at least about 1.2 meq/gram. Cationic charge density of the cationic polymer can be determined according to the Kjeldahl Method. Those skilled in the art will recognize that the charge density of amino-containing polymers may vary depending upon pH and the isoelectric point of the amino groups. The charge density should be within the above limits at the pH of intended use.
Any anionic counterions can be utilized for the cationic polymers so long as the water solubility criteria is met. Suitable counterions include halides (e.g., Cl, Br, I, or F, preferably Cl, Br, or I), sulfate, and methylsulfate. Others can also be used, as this list is not exclusive.
The cationic nitrogen-containing moiety will be present generally as a substituent, on a fraction of the total monomer units of the cationic hair conditioning polymers. Thus, the cationic polymer can comprise copolymers, terpolymers, etc. of quaternary ammonium or cationic amine-substituted monomer units and other non-cationic units referred to herein as spacer monomer units. Such polymers are known in the art, and a variety can be found in the CTFA Cosmetic Ingredient Dictionary, 3rd edition, edited by Estrin, Crosley, and Haynes, (The Cosmetic, Toiletry, and Fragrance Association, Inc., Washington, D.C., 1982).
Suitable cationic polymers include, for example, copolymers of vinyl monomers having cationic amine or quaternary ammonium functionalities with water soluble spacer monomers such as acrylamide, methacrylamide, alkyl and dialkyl acrylamides, alkyl and dialkyl methacrylamides, alkyl acrylate, alkyl methacrylate, vinyl caprolactone, and vinyl pyrrolidone. The alkyl and dialkyl substituted monomers preferably have C1-C7 alkyl groups, more preferably C1-C3 alkyl groups. Other suitable spacer monomers include vinyl esters, vinyl alcohol (made by hydrolysis of polyvinyl acetate), maleic anhydride, propylene glycol, and ethylene glycol.
The cationic amines can be primary, secondary, or tertiary amines, depending upon the particular species and the pH of the composition. In general, secondary and tertiary amines, especially tertiary amines, are preferred.
Amine-substituted vinyl monomers can be polymerized in the amine form, and then optionally can be converted to ammonium by a quaternization reaction. Amines can also be similarly quaternized subsequent to formation of the polymer. For example, tertiary amine functionalities can be quaternized by reaction with a salt of the formula R′X wherein R′ is a short chain alkyl, preferably a C1-C7 alkyl, more preferably a C1-C3 alkyl, and X is an anion which forms a water soluble salt with the quaternized ammonium.
Suitable cationic amino and quaternary ammonium monomers include, for example, vinyl compounds substituted with dialkylaminoalkyl acrylate, dialkylaminoalkyl methacrylate, monoalkylaminoalkyl acrylate, monoalkylaminoalkyl methacrylate, trialkyl methacryloxyalkyl ammonium salt, trialkyl acryloxyalkyl ammonium salt, diallyl quaternary ammonium salts, and vinyl quaternary ammonium monomers having cyclic cationic nitrogen-containing rings such as pyridinium, imidazolium, and quaternized pyrrolidone, e.g., alkyl vinyl imidazolium, alkyl vinyl pyridinium, alkyl vinyl pyrrolidone salts. The alkyl portions of these monomers are preferably lower alkyls such as the C1-C3 alkyls, more preferably C1 and C2 alkyls. Suitable amine-substituted vinyl monomers for use herein include dialkylaminoalkyl acrylate, dialkylaminoalkyl methacrylate, dialkylaminoalkyl acrylamide, and dialkylaminoalkyl meth-acrylamide, wherein the alkyl groups are preferably C1-C7 hydrocarbyls, more preferably C1-C3, alkyls.
The cationic polymers hereof can comprise mixtures of monomer units derived from amine- and/or quaternary ammonium-substituted monomer and/or compatible spacer monomers.
Suitable cationic hair conditioning polymers include, for example: copolymers of 1-vinyl-2-pyrrolidone and 1-vinyl-3-methylimidazolium salt (e.g., chloride salt) (referred to in the industry by the Cosmetic, Toiletry, and Fragrance Association, “CTFA”, as Polyquaternium-16), such as those commercially available from BASF Wyandotte Corp. (Parsippany, N.J., USA) under the LUVIQUAT tradename (e.g., LUVIQUAT FC 370); co-polymers of 1-vinyl-2-pyrrolidone and dimethylaminoethyl methacrylate (referred to in the industry by CTFA as Polyquaternium-11) such as those commercially available from Gaf Corporation (Wayne, N.J., USA) under the GAFQUAT tradename (e.g., GAFQUAT 755N); cationic diallyl quaternary ammonium-containing polymers, including, for example, dimethyldiallylammonium chloride homopolymer and copolymers of acrylamide and dimethyldiallylammonium chloride, referred to in the industry (CTFA) as Polyquaternium 6 and Polyquaternium 7, respectively; and mineral acid salts of amino-alkyl esters of homo- and co-polymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms, as described in U.S. Pat. No. 4,009,256.
Other cationic polymers that can be used include polysaccharide polymers, such as cationic cellulose derivatives and cationic starch derivatives.
Cationic polysaccharide polymer materials suitable for use herein include those of the formula:
wherein: A is an anhydroglucose residual group, such as a starch or cellulose anhydroglucose residual, R is an alkylene oxyalkylene, polyoxyalkylene, or hydroxyalkylene group, or combination thereof, R1, R2, and R3 independently are alkyl, aryl, alkylaryl, arylalkyl, alkoxyalkyl, or alkoxyaryl groups, each group containing up to about 18 carbon atoms, and the total number of carbon atoms for each cationic moiety (i.e., the sum of carbon atoms in R1, R2 and R3) preferably being about 20 or less, and X is an anionic counterion, as previously described.
Cationic cellulose is available from Amerchol Corp. (Edison, N.J., USA) in their Polymer JR® and LR® series of polymers, as salts of hydroxyethyl cellulose reacted with trimethyl ammonium substituted epoxide, referred to in the industry (CTFA) as Polyquaternium 10. Another type of cationic cellulose includes the polymeric quaternary ammonium salts of hydroxyethyl cellulose reacted with lauryl dimethyl ammonium-substituted opoxide, referred to in the industry (CTFA) as Polyquaternium 24. These materials are available from Amerchol Corp. (Edison, N.J., USA) under the tradenarne Polymer LM-200®.
Other cationic polymers that can be used include cationic guar gum derivatives, such as guar hydroxypropyltrimonium chloride (commercially available from Celanese Corp. in their Jaguar R series). Other materials include quaternary nitrogen-containing cellulose ethers (e.g., as described in U.S. Pat. No. 3,962,418), and copolymers of etherified cellulose and starch (e.g., as described in U.S. Pat. No. 3,958,581)
As discussed above, the cationic polymer hereof is water soluble. This does not mean, however, that it must be soluble in the composition. Preferably however, the cationic polymer is either soluble in the composition, or in a complex coacervate phase in the composition formed by the cationic polymer and anionic material. Complex coacervates of the cationic polymer can be formed with anionic surfactants or with anionic polymers that can optionally be added to the compositions hereof (e.g., sodium polystyrene sulfonate).
The compositions hereof can also include nonvolatile soluble or insoluble silicone conditioning actives. By soluble what is meant is that the silicone conditioning active is miscible with the aqueous carrier of the composition so as to form part of the same phase. By insoluble what is meant is that the silicone forms a separate, discontinuous phase from the aqueous carrier, such as in the form of an emulsion or a suspension of droplets of the silicone.
The silicone hair conditioning active will be used in the compositions hereof at levels of from about 0.05% to about 10% by weight of the composition, preferably from about 0.1% to about 8%. In rinse off hair care compositions of the present invention the silicone hair conditioning active can be from about 0.5% to about 5%, and in leave on hair care compositions of the present invention the silicone hair conditioning active can be from about 0.5% to about 10%.
Soluble silicones include silicone copolyols, such as dimethicone copolyols, e.g. polyether siloxane-modified polymers, such as polypropylene oxide, polyethylene oxide modified polydimethylsiloxane, wherein the level of ethylene and/or propylene oxide sufficient to allow solubility in the composition.
Preferred, however, are insoluble silicones. The insoluble silicone hair conditioning active for use herein will preferably have viscosity of from about 1,000 to about 2,000,000 centistokes at 25° C., more preferably from about 10,000 to about 1,800,000 centistokes, even more preferably from about 100,000 to about 1,500,000 centistokes. The viscosity can be measured by means of a glass capillary viscometer as set forth in Dow Corning Corporate Test Method CTM0004, Jul. 20, 1970.
Suitable insoluble, nonvolatile silicone fluids include polyalkyl siloxanes, polyaryl siloxanes, polyalkylaryl siloxanes, polyether siloxane copolymers, and mixtures thereof. Other insoluble, nonvolatile silicone fluids having hair conditioning properties can also be used. The term “nonvolatile” as used herein shall mean that the silicone has a boiling point of at least about 260° C., preferably at least about 275° C., more preferably at least about 300° C. Such materials exhibit very low or no significant vapor pressure at ambient conditions. The term “silicone fluid” shall mean flowable silicone materials having a viscosity of less than 2,000,000 centistokes at 25° C. Generally, the viscosity of the fluid will be between about 5 and 2,000,000 centistokes at 25° C., preferably between about 10 and about 300,000 centistokes.
Silicone fluids hereof also include polyalkyl or polyaryl siloxanes with the following structure:
wherein R is alkyl or aryl, and x is an integer from about 7 to about 8,000 may be used. “A” represents groups which block the ends of the silicone chains.
The alkyl or aryl groups substituted on the siloxane chain (R) or at the ends of the siloxane chains (A) may have any structure as long as the resulting silicones remain fluid at room temperature, are hydrophobic, are neither irritating, toxic nor otherwise harmful when applied to the hair, are compatible with the other components of the composition, are chemically stable under normal use and storage conditions, and are capable of being deposited on and of conditioning hair.
Suitable A groups include methyl, methoxy, ethoxy, propoxy, and aryloxy. The two R groups on the silicone atom may represent the same group or different groups. Preferably, the two R groups represent the same group. Suitable R groups include methyl, ethyl, propyl, phenyl, methylphenyl and phenylmethyl. The preferred silicones are polydimethyl siloxane, polydiethylsiloxane, and polymethylphenylsiloxane. Polydimethylsiloxane is especially preferred.
The nonvolatile polyalkylsiloxane fluids that may be used include, for example, polydimethylsiloxanes. These siloxanes are available, for example, from the General Electric Company in their ViscasilR and SF 96 series, and from Dow Corning in their Dow Corning 200 series.
The polyalkylaryl siloxane fluids that may be used, also include, for example, polymethylphenylsiloxanes. These siloxanes are available, for example, from the General Electric Company as SF 1075 methyl phenyl fluid or from Dow Corning as 556 Cosmetic Grade Fluid.
Especially preferred, for enhancing the shine characteristics of hair, are highly arylated silicones, such as highly phenylated polyethyl silicone having refractive indices of about 1.46 or higher, especially about 1.52 or higher. When these high refractive index silicones are used, they should be mixed with a spreading agent, such as a surfactant or a silicone resin, as described below to decrease the surface tension and enhance the film forming ability of the material.
The polyether siloxane copolymers that may be used include, for example, a polypropylene oxide modified polydimethylsiloxane (e.g., Dow Corning DC-1248) although ethylene oxide or mixtures of ethylene oxide and propylene oxide may also be used. The ethylene oxide and polypropylene oxide level should be sufficiently low to prevent solubility in the composition hereof.
References disclosing suitable silicone fluids include U.S. Pat. No. 2,826,551, Geen; U.S. Pat. No. 3,964,500, Drakoff, issued Jun. 22, 1976; U.S. Pat. No. 4,364,837, Pader; and British Patent 849,433, Woolston. Also incorporated herein by reference is Silicon Compounds distributed by Petrarch Systems, Inc., 1984. This reference provides an extensive (though not exclusive) listing of suitable silicone fluids.
Another silicone hair conditioning material that can be especially useful in the silicone conditioning actives is insoluble silicone gum. The term “silicone gum”, as used herein, means polyorganosiloxane materials having a viscosity at 25° C. of greater than or equal to 1,000,000 centistokes. Silicone gums are described by Petrarch and others including U.S. Pat. No. 4,152,416, Spitzer et al., issued May 1, 1979 and Noll, Walter, Chemistry and Technology of Silicones, New York: Academic Press 1968. Also describing silicone gums are General Electric Silicone Rubber Product Data Sheets SE 30, SE 33, SE 54 and SE 76. The “silicone gums” will typically have a mass molecular weight in excess of about 200,000, generally between about 200,000 and about 1,000,000. Specific examples include polydimethylsiloxane, (polydimethylsiloxane) (methylvinylsiloxane) copolymer, poly(dimethylsiloxane) (diphenyl siloxane)(methylvinylsiloxane) copolymer and mixtures thereof.
Preferably the silicone hair conditioning active comprises a mixture of a polydimethylsiloxane gum, having a viscosity greater than about 1,000,000 centistokes and polydimethylsiloxane fluid having a viscosity of from about 10 centistokes to about 100,000 centistokes, wherein the ratio of gum to fluid is from about 30:70 to about 70:30, preferably from about 40:60 to about 60:40.
An optional ingredient that can be included in the silicone conditioning active is silicone resin. Silicone resins are highly crosslinked polymeric siloxane systems. The crosslinking is introduced through the incorporation of trifunctional and tetrafunctional silanes with monofunctional or difunctional, or both, silanes during manufacture of the silicone resin. As is well understood in the art, the degree of crosslinking that is required in order to result in a silicone resin will vary according to the specific silane units incorporated into the silicone resin. In general, silicone materials which have a sufficient level of trifunctional and tetrafunctional siloxane monomer units (and hence, a sufficient level of crosslinking) such that they dry down to a rigid, or hard, film are considered to be silicone resins. The ratio of oxygen atoms to silicon atoms is indicative of the level of crosslinking in a particular silicone material. Silicone materials which have at least about 1.1 oxygen atoms per silicon atom will generally be silicone resins herein. Preferably, the ratio of oxygen:silicon atoms is at least about 1.2:1.0. Silanes used in the manufacture of silicone resins include monomethyl-, dimethyl-, trimethyl-, monophenyl-, diphenyl-, methylphenyl-, monovinyl-, and methylvinyl-chlorosilanes, and tetrachlorosilane, with the methyl-substituted silanes being most commonly utilized. Preferred resins are offered by General Electric as GE SS4230 and SS4267. Commercially available silicone resins will generally be supplied in a dissolved form in a low viscosity volatile or nonvolatile silicone fluid. The silicone resins for use herein should be supplied and incorporated into the present compositions in such dissolved form, as will be readily apparent to those skilled in the art.
Silicone resins can enhance deposition of silicone on the hair and can enhance the glossiness of hair with high refractive index volumes.
Background material on silicones including sections discussing silicone fluids, gums, and resins, as well as manufacture of silicones, can be found in Encyclopedia of Polymer Science and Engineering, Volume 15, Second Edition, pp 204-308, John Wiley & Sons, Inc., 1989.
Silicone materials and silicone resins in particular, can conveniently be identified according to a shorthand nomenclature system well known to those skilled in the art as “MDTQ” nomenclature. Under this system, the silicone is described according to presence of various siloxane monomer units which make up the silicone. Briefly, the symbol M denotes the monofunctional unit (CH3)3SiO0.5; D denotes the difunctional unit (CH3)2SiO; T denotes the trifunctional unit (CH3)SiO1.5; and Q denotes the quadri- or tetra-functional unit SiO2. Primes of the unit symbols, e.g., M′, D′, T′, and Q′ denote substituents other than methyl, and must be specifically defined for each occurrence. Typical alternate substituents include groups such as vinyl, phenyls, amines, hydroxyls, etc. The molar ratios of the various units, either in terms of subscripts to the symbols indicating the total number of each type of unit in the silicone (or an average thereof) or as specifically indicated ratios in combination with molecular weight complete the description of the silicone material under the MDTQ system. Higher relative molar amounts of T, Q, T′ and/or Q′ to D, D′, M and/or or M′ in a silicone resin is indicative of higher levels of crosslinking. As discussed before, however, the overall level of crosslinking can also be indicated by the oxygen to silicon ratio.
The silicone resins for use herein which are preferred are MQ, MT, MTQ, MQ and MDTQ resins. Thus, the preferred silicone substituent is methyl. Especially preferred are MQ resins wherein the M:Q ratio is from about 0.5:1.0 to about 1.5:1.0 and the average molecular weight of the resin is from about 1000 to about 10,000.
The compositions of the present invention may also contain an anti-dandruff active. Suitable, non-limiting examples of anti-dandruff particulates include: pyridinethione salts, zinc carbonate, azoles, such as ketoconazole, econazole, and elubiol, selenium sulfide, particulate sulfur, and mixtures thereof. A typical anti-dandruff particulate is pyridinethione salt. Such anti-dandruff particulate should be physically and chemically compatible with the components of the composition, and should not otherwise unduly impair product stability, aesthetics or performance.
a. Pyridinethione Salts
Pyridinethione anti-dandruff particulates, especially 1-hydroxy-2-pyridinethione salts, are suitable particulate anti-dandruff actives for use in compositions of the present invention. The concentration of pyridinethione anti-dandruff particulate typically ranges from about 0.1% to about 4%, by weight of the composition, generally from about 0.1% to about 3%, commonly from about 0.3% to about 2%. Suitable pyridinethione salts include those formed from heavy metals such as zinc, tin, cadmium, magnesium, aluminum and zirconium, generally zinc, typically the zinc salt of 1-hydroxy-2-pyridinethione (known as “zinc pyridinethione” or “ZPT”), commonly 1-hydroxy-2-pyridinethione salts in platelet particle form, wherein the particles have an average size of up to about 20μ (microns), typically up to about 5μ, commonly up to about 2.5μ. Salts formed from other cations, such as sodium, may also be suitable. Pyridinethione anti-dandruff actives are described, for example, in U.S. Pat. Nos. 2,809,971; 3,236,733; 3,753,196; 3,761,418; 4,345,080; 4,323,683; 4,379,753; and 4,470,982.
b. Anti-Microbial Actives
In addition to the anti-dandruff active selected from polyvalent metal salts of pyrithione, the present invention may further comprise one or more anti-fungal or anti-microbial actives in addition to the metal pyrithione salt actives. Suitable anti-microbial actives include coal tar, sulfur, whitfield's ointment, castellani's paint, aluminum chloride, gentian violet, octopirox (piroctone olamine), ciclopirox olamine, undecylenic acid and it's metal salts, potassium permanganate, selenium sulphide, sodium thiosulfate, propylene glycol, oil of bitter orange, urea preparations, griseofulvin, 8-Hydroxyquinoline ciloquinol, thiobendazole, thiocarbamates, haloprogin, polyenes, hydroxypyridone, morpholine, benzylamine, allylamines (such as terbinafine), tea tree oil, clove leaf oil, coriander, palmarosa, berberine, thyme red, cinnamon oil, cinnamic aldehyde, citronellic acid, hinokitol, ichthyol pale, Sensiva SC-50, Elestab HP-100, azelaic acid, lyticase, iodopropynyl butylcarbamate (IPBC), isothiazalinones such as octyl isothiazalinone and azoles, and combinations thereof. Typical anti-microbials include itraconazole, ketoconazole, selenium sulphide and coal tar.
i. Azoles
Azole anti-microbials include imidazoles such as benzimidazole, benzothiazole, bifonazole, butaconazole nitrate, climbazole, clotrimazole, croconazole, eberconazole, econazole, elubiol, fenticonazole, fluconazole, flutimazole, isoconazole, ketoconazole, lanoconazole, metronidazole, miconazole, neticonazole, omoconazole, oxiconazole nitrate, sertaconazole, sulconazole nitrate, tioconazole, thiazole, and triazoles such as terconazole and itraconazole, and combinations thereof. When present in the composition, the azole anti-microbial active is included in an amount from about 0.01% to about 5%, typically from about 0.1% to about 3%, and commonly from about 0.3% to about 2%, by weight of the composition. Especially common for use herein is ketoconazole.
ii. Selenium Sulfide
Selenium sulfide is a particulate anti-dandruff active suitable for use in the anti-microbial compositions of the present invention, effective concentrations of which range from about 0.1% to about 4%, by weight of the composition, typically from about 0.3% to about 2.5%, commonly from about 0.5% to about 1.5%. Selenium sulfide is generally regarded as a compound having one mole of selenium and two moles of sulfur, although it may also be a cyclic structure that conforms to the general formula SexSy, wherein x+y=8. Average particle diameters for the selenium sulfide are typically less than 15 μm, as measured by forward laser light scattering device (e.g. Malvern 3600 instrument), typically less than 10 μm. Selenium sulfide compounds are described, for example, in U.S. Pat. Nos. 2,694,668; 3,152,046; 4,089,945; and 4,885,107.
iii. Sulfur
Sulfur may also be used as a particulate anti-microbial/anti-dandruff active in the anti-microbial compositions of the present invention. Effective concentrations of the particulate sulfur are typically from about 1% to about 4%, by weight of the composition, typically from about 2% to about 4%.
iv. Keratolytic Actives
The present invention may further comprise one or more keratolytic actives such as Salicylic Acid.
v. Additional Anti-microbial Actives
Additional anti-microbial actives of the present invention may include extracts of melaleuca (tea tree) and charcoal. The present invention may also comprise combinations of anti-microbial actives. Such combinations may include octopirox and zinc pyrithione combinations, pine tar and sulfur combinations, salicylic acid and zinc pyrithione combinations, octopirox and climbasole combinations, and salicylic acid and octopirox combinations, and mixtures thereof and are typically from about 1% to about 4%, commonly from about 2% to about 4%.
The compositions herein can contain a variety of other optional components suitable for rendering such compositions more cosmetically or aesthetically acceptable or to provide them with additional usage benefits. Such conventional optional ingredients are well-known to those skilled in the art.
A wide variety of additional ingredients can be formulated into the present composition. These include: other conditioning actives; hair-hold polymers; detersive surfactants such as anionic, nonionic, amphoteric, and zwitterionic surfactants; additional thickening actives and suspending actives such as xanthan gum, guar gum, hydroxyethyl cellulose, methyl cellulose, hydroxyethylcellulose, starch and starch derivatives; viscosity modifiers such as methanolamides of long chain fatty acids such as cocomonoethanol amide; crystalline suspending actives; pearlescent aids such as ethylene glycol distearate; preservatives such as benzyl alcohol, methyl paraben, propyl paraben and imidazolidinyl urea; polyvinyl alcohol; ethyl alcohol; pH adjusting actives, such as citric acid, sodium citrate, succinic acid, phosphoric acid, sodium hydroxide, sodium carbonate; salts, in general, such as potassium acetate and sodium chloride; coloring actives, such as any of the FD&C or D&C dyes; hair oxidizing (bleaching) actives, such as hydrogen peroxide, perborate and persulfate salts; hair reducing actives, such as the thioglycolates; perfumes; sequestering actives, such as disodium ethylenediamine tetra-acetate; and polymer plasticizing actives, such as glycerin, disobutyl adipate, butyl stearate, sunscreens, and propylene glycol. The compositions of the present invention may contain also vitamins and amino acids such as: water soluble vitamins such as vitamin B1, B2, B6, B12, C, pantothenic acid, pantothenyl ethyl ether, panthenol, biotin, and their derivatives, water soluble amino acids such as asparagine, alanine, indole, glutamic acid and their salts, water insoluble vitamins such as vitamin A, D, E, and their derivatives, water insoluble amino acids such as tyrosine, tryptamine, and their salts.
Such optional ingredients generally are used individually at levels from about 0.01% to about 10.0%, preferably from about 0.05% to about 5.0% by weight of the composition. The hair care compositions of the present invention are used in conventional ways to provide the conditioning and other benefits of the present invention. The use of the composition depends upon the type of composition employed but generally involves application of an effective amount of the product to the hair, which may then be rinsed from the hair (as in the case of hair rinses) or allowed to remain on the hair (as in the case of gels, lotions, and creams). “Effective amount” means an amount sufficient enough to provide a dry combing benefit. In general, from about 1 g to about 50 g is applied to the hair on the scalp. The composition is distributed throughout the hair, typically by rubbing or massaging the hair and scalp. Preferably, the composition is applied to wet or damp hair prior to drying of the hair. After such compositions are applied to the hair, the hair is dried and styled in accordance with the preference of the user. In the alternative, the composition is applied to dry hair, and the hair is then combed or styled in accordance with the preference of the user.
After application of at least one hair care composition to the hair, the heating system of the present invention is applied to the hair. This heating system can be applied either i) after one or multiple hair care compositions are applied, or ii) the hair can be exposed to the heating system and then a hair care composition can be applied. The method can further comprise the step of increasing hair moisture level by at least about 300% versus hair moisture level prior to application of the system, over a time period of less than about 30 minutes.
The compositions of the present invention can be in the form of rinse-off products or leave-on products, and can be formulated in a wide variety of product forms, including but not limited to creams, gels, emulsions, mousses and sprays. Additionally, the hair care compositions of the present invention can be a conditioner, a shampoo, a styling product, an anti-dandruff product and/or any combination thereof.
The present invention has many uses, non-limiting examples of which include delivering consistent, safe, efficient, and sustained moist heat to the hair. This moist heat when used in combination with a hair care active, delivers a hair benefit including, but not limited to, conditioned hair, smoother hair, shinier hair, softer hair, healthier hair, dandruff free hair, and combinations thereof.
In one embodiment of the present invention, hair is i) treated with a rinse off conditioner, ii) hair is rinsed, iii) hair is treated with a leave on conditioner, and iv) a portable moist heat delivery system is applied to the hair and activated for thirty minutes. Twelve individuals with damaged hair were treated with this method. The Double Combing results (as shown in
Because the temperature of the water vapor-air mixture of the system in use on a body is only a few degrees above normal skin temperature of from about 32° C. to about 35° C., and the dew point temperature of the water vapor-air mixture is approximately that of normal skin temperature when it reaches the skin and/or hair, heat can be safely transferred to the skin and/or hair via latent heat of condensation of water from the water vapor-air mixture. Thus, the system is able to safely deliver a large amount of heat to the skin and/or hair, wherein from about 15% to about 95%, alternatively from about 20% to about 80% and alternatively from about 40% to about 75% of the heat is delivered as latent heat. In one embodiment, the moist heat system delivers about 15% to about 95% of the heat as latent heat of condensation for at least 10 minutes, alternatively, at least 30 minutes, or at least 1 hour, in certain embodiments at least 3 hours, or alternatively at least 5 hours.
In addition to delivering moist heat, the moist heat system may also provide moisturization to the hair and scalp as the water vapor condenses to water and delivers the latent heat of condensation to the scalp and/or hair.
Skin and/or hair surface temperature is measured by the following method. All measurements are made at ambient conditions. The temperature range during the measurements is 21° C.-23° C. Relative humidity range is 38%-42%. Temperature measurements may be made using a thermocouple. The thermocouple may be positioned between the hair and the latent heat delivery surface and/or hair contact layer. In one embodiment the temperature measurements are made with K-type thermocouples (Omega, part # 5SRTC-TT-K-40-72) and recorded by temperature data logger (Omega, HH84). To measure the temperature of the surface of a user's skin and/or hair, the user sits in a room at about 22° C. for about 20 minutes to normalize to the room temperature and conditions. During that time, a thermocouple is placed and taped on the skin and/or hair surface, taking care that the tape is not placed over the sensing area of the thermocouple. Upon expiration of the equilibration time, temperature can be measured and recorded for a desired period of time.
If the effect of a system of the present invention on the skin and/or hair surface temperature is measured, each system of the present invention to be measured is constructed then sealed in an impermeable container and set aside for 24 hours to equilibrate before testing. When a system is to be tested, it is removed from a protective package and placed on a skin and/or hair surface, on top of the thermocouple. Skin and/or hair temperature is measured before application of the system, and recorded for 60 minutes after application of the system and initiation of heating.
The temperature of the water vapor-air mixture delivered to the skin and/or hair surface can also be measured by placing thermocouples on a user's skin and/or hair. Skin and/or hair temperature is measured before application of the system, and is recorded for 60 minutes after application of the system and initiation of heating.
The dew point temperature is preferably measured when the moist heat system is activated and in position on a user as the dew point temperature of particular interest is related to the amount of water vapor between the user and the moist heat system. The amount of water vapor between the body and the moist heat wrap is dependent on the amount of water vapor generated by the device minus the amount of water vapor condensed and the amount of water vapor that flows out of the device. The dew point may be measured, for example with a HUMICAP® HMT337 dew point transmitter with Stainless Steel HM47453P filter, available from Vaisala, Woburn Mass., USA.
In one embodiment, the system of the present invention as described herein can generate and deliver from about 75 W/m2 to about 500 W/m2, alternatively from about 100 W/m2 to about 200 W/m2, alternatively from about 200 W/m2 to about 500 W/m2, and alternatively from about 300 W/m2 to about 500 W/m2 of heat flux at a safe skin and/or hair temperature. In another embodiment, the system of the present invention as described herein can generate and deliver from about 180 W/m2 to about 500 W/m2, alternatively from about 200 W/m2 to about 500 W/m2, and alternatively from about 220 W/m2 to about 300 W/m2 of heat flux at a safe skin and/or hair temperature.
The system generates and delivers heat to a surface of the skin and/or hair wherein from about 15% to about 95%, alternatively from about 20% to about 80%, and about 40% to about 75% of the heat delivered to a surface of the skin and/or hair is delivered as latent heat upon condensation of the water vapor-air mixture. Without wishing to be held by any theory, it is believed that the remainder of the heat transferred to the user or hair may be heat transferred by conduction. Because a majority of the heat transfer is through condensation on the body, through control of the dew point temperature by water vapor-air mixing, the system of the present invention can deliver peak heating levels to the body of up to two to five times that of a conventional dry heating wrap while maintaining constant skin temperature of about 43° C. or less, thereby providing a safe usage experience for the user.
The system of the present invention also generates from about 0.05 mg water vapor/min/cm2 to about 2.5 mg water vapor/min/cm2 of water vapor generating portion, and alternatively from about 0.1 mg water vapor/min/cm2 to about 2.0 mg water vapor/min/cm2 of water vapor generating portion, wherein the water vapor delivers moisture to the surface via condensation onto the surface of the skin and/or hair.
The amount of water vapor generated, and water vapor generation rate can be measured by measuring the weight change of a system of the present invention, or other exothermic heating device, from before initiation of heating to after the system is spent, and over time during use of the system. To measure and record the weight change, a Mettler-Toledo Balance Model PG503-S is connected to a computer running Software Wedge v3.0C—Professional software using a RS232C interface cable. Prior to testing the balance is calibrated according to the manufacturer's instructions. A 1.59 mm ( 1/16 inch) thick polystyrene foam sheet is placed on top of the scale of the balance and the balance is zeroed.
The system to be tested is removed from an air-tight foil pouch where it is stored after manufacture, and is placed in the center of the polystyrene foam sheet. To begin the test, simultaneously “menu” on the balance and “start/stop” on a stop watch function on the computer are pressed. Using the stopwatch as a reference, “menu” is pressed on the balance once every minute to log the weight of the system being tested into the software. The starting weight of the exothermic heating device and the weight of the exothermic heating device thereafter are recorded until the system is spent, and thereby moisture loss from the start to the end of the reaction can be measured.
The amount of weight loss is correlated to the amount of water loss, which estimates the amount of water vapor generated during the reaction. With an exothermic composition such as that of the present invention, because none of the other components of the exothermic composition is lost during the reaction, and water is not consumed as part of the reaction, weight lost can be correlated to water lost and water vapor generated. Measurements based on weight lost, and calculations of water vapor generated are approximations because during the course of the reaction iron oxide is produced, and thus some weight is also gained during the course of the reaction. However, a minimal amount of iron oxide is produced and thus a de minimus amount of weight is gained. Therefore, the amount of weight lost approximates the amount of water lost.
Amount of water vapor generated per area of skin and/or hair of a user can be calculated by dividing the total amount of water vapor generated by the system by the area of skin and/or hair to which a system is applied. Water vapor generated per unit time can also be calculated by dividing the amount of water vapor generated by a system by the duration of water vapor generation. One of ordinary skill in the art would understand how to perform such calculations, either manually or using computer software.
In addition, the system can increase skin and/or hair moisture level by at least about 300% versus skin and/or hair moisture level prior to application of the system, over a time period of less than about 30 minutes.
Amount of skin and/or hair moisture and increase in skin and/or hair moisture is measured with a Corneometer 810 capacitance skin moisture meter (Courage Khazaka Electronics, Cologne, Del.). The corneometer determines the humidity level of the stratum corneum of the skin by electrical capacitance. Alteration in skin hydration level results in a change in capacitance. The capacitance probe is applied for one second at a pressure of 7.1 N/cm2. The degree of capacitance is indicated from 1-100 units. One unit represents a water content of 0.02 mg/cm2 at a measuring depth of 20 nm. Very dry is less than 30 units, dry is 30-45 units and sufficiently moisturized is greater than 45 units.
Tissue (i.e. skin and/or hair in this case) capacitance is measured by applying electromagnetic waves at a frequency of 100,000 cycles/second (Hz), to a depth of 20 nm, to image the skin surface. The probe is placed on the skin and/or hair of a test subject at a location desired to be studied. Prior to testing, the subject sits in a room at about 22° C. and 40% relative humidity for 20 minutes, to come to a normalized condition. Capacitance, from which moisture is calculated, is measured before and immediately after removal of the heating modality.
A kit can be made including a combination of one or more of the aforementioned hair care compositions and a portable moist heat delivery system.
The following examples further describe and demonstrate embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope of the invention. All exemplified concentrations are weight-weight percents, unless otherwise specified.
Compositions in accordance with above examples can be prepared by any conventional method well known in the art. They are suitably made as follows: deionized water is heated to 85° C. and cationic surfactants and high melting point fatty compounds are mixed in. If necessary, cationic surfactants and fatty alcohols can be pre-melted at 85° C. before addition to the water. The water is maintained at a temperature of about 85° C. until the components are homogenized, and no solids are observed. The mixture is then cooled to about 55° C. and maintained at this temperature, to form a gel matrix. Aminosilicones, or a blend of aminosilicones and a low viscosity fluid, or an aqueous dispersion of an aminosilicone, or the dimethicone, are added to the gel matrix. When included, other additional components such as perfumes and preservatives are added with agitation. The gel matrix is maintained at about 50° C. during this time with constant stirring to assure homogenization. After it is homogenized, it is cooled to room temperature.
Compositions in accordance with above examples can be prepared by any conventional method well known in the art. They are suitably made as follows: deionized water is heated to 85° C. and the first nine ingredients are mixed in. The water is maintained at a temperature of about 85° C. until the components are homogenized, and no solids are observed. The mixture is then cooled to about 55° C. The remaining materials are mixed in. The gel matrix is maintained at about 50° C. during this time with constant stirring to assure homogenization. After it is homogenized, it is cooled to room temperature.
The water vapor source exemplified below is exothermic heat cells filled with a particulate exothermic composition for use in the water vapor generating portion of the system of the present invention.
The particulate exothermic compositions exemplified below are prepared by using conventional blending techniques to form the particulate exothermic compositions, wherein the resultant compositions provide for the construction of heat cells of the present invention.
A pre-mix is prepared by adding activated carbon and water into a blender or mixer such as a Littleford Day Mixer, and mixing for about ten minutes. A polyacrylate absorbent gelling material is then added, and the mixture is mixed for about 10 minutes. Next, sponge iron powder is added to the mixer, and the resultant pre-mix is mixed for about 5 minutes.
Approximately 2.2 g of the resultant pre-mix composition are added to each preformed pocket, which pockets have been created with a vacuum to form the pockets, in a sheet of polypropylene/EVA coextruded film.
Next, a brine solution is prepared by adding water, sodium chloride, and optionally sodium thiosulfate into a mixer and mixing for about fifteen minutes. The resultant brine solution is then rapidly dosed onto the pre-mix composition.
An aerated skin-facing surface of polypropylene SMMS non-woven material is placed over the pockets containing the pre-mix and brine, facing the EVA side of the preformed pocket-containing film sheet. The film sheet and SMMS are bonded together using a low heat, forming a unified structure. The resulting unified structure contains heat cells containing the particulate exothermic composition sealed in the pockets between the opposing surfaces of the aerated surface and the opposed film layer surface.
The cells begin to generate heat shortly after the brine is added to the particulate composition, therefore the top and bottom surfaces are bonded and the finished heat cells are quickly packaged in an air tight secondary packaging for future use.
Table 1 illustrates different particulate exothermic compositions of heat cells of the present invention.
Example embodiments of the present invention are described below with reference to the Figures. The same symbols represent the same structural elements throughout.
The heat cells have a particulate exothermic composition 10 dosed in a pocket formed in an opposed surface 12 of non-air permeable, non-moisture permeable polypropylene/EVA film layer opposing a polypropylene SMMS aerated skin-facing surface 14.
Attached to the opposed surface 12 is a 1.59 mm ( 1/16 inch) insulative polypropylene foam layer 16. Attached to foam layer 16 is an outermost polypropylene non-woven layer 18.
Adjacent the aerated skin-facing surface 14 is a 3 mm thick first water vapor-air mixing layer 20 of high loft polyethylene/polyester non-woven batting. Adjacent the first water vapor-air mixing layer 20 is a first water vapor-air distribution layer 22 of 1.59 mm ( 1/16 inch) thick perforated polypropylene foam. Adjacent the first water vapor-air distribution layer 22 is a second 3 mm thick water vapor-air mixing layer 24 of high loft polyethylene/polyester non-woven batting. Adjacent the second water vapor-air mixing layer 24 is a second water vapor-air distribution layer 26 of 1.59 mm ( 1/16 inch) thick perforated polypropylene foam. Attached to the second water vapor-air distribution layer 26 are two skin-contact layers of polypropylene non-woven material 28. The layers are sealed together around the periphery of the layers to form a system.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application claims the benefit of U.S. Provisional Application No. 61/053,480, filed May 15, 2008; U.S. Provisional Application No. 61/093,009, filed Aug. 29, 2008; and U.S. Provisional Application No. 61/093,043, filed Aug. 29, 2008.
| Number | Date | Country | |
|---|---|---|---|
| 61093043 | Aug 2008 | US | |
| 61093009 | Aug 2008 | US | |
| 61053480 | May 2008 | US |
