MX2008007613A - Therapeutic kit employing a thermal insert - Google Patents

Abstract

A therapeutic kit for providing heat to an area of the body is provided. The therapeutic kit may be used to treat a variety of injuries to muscles, ligaments, tendons, etc., including arm, leg, ankle, knee, shoulder, foot, neck, back, elbow, wrist, hand, chest, finger, toe injuries, and so forth. Regardless of its intended use, the therapeutic kit generally employs a pad that receives a thermal insert. The thermal insert includes a substrate containing an exothermic coating that is capable of generating heat in the presence of oxygen and moisture. One particular benefit of the thermal insert of the present invention is that it is disposable. Thus, when the thermal insert exhausts its heat-producing capacity, a new insert may simply be utilized. This allows for the continued use of the extensible material, resulting in substantial cost savings to the consumer.

Description

THERAPEUTIC CASE THAT USES A THERMAL INSERT Background of the Invention Therapeutic bags or pads are often used to warm muscles or reduce cramps. Most conventional pads require the use of external heat or reagents that undergo an exothermic reaction when mixed (eg, chemical pads). "Bag-in-bag" chemical pads, for example, typically have a smaller bag containing a reagent that is enclosed by a larger bag that contains the other reagent. However, such chemical pads have a large surface area and the first reagent and the second reagent. Therefore, the possibility that reagents may prematurely migrate through the smaller bag is increased. Although migration can be decreased with thicker materials, this sometimes results in an increased difficulty in tearing the material. Unlike "bag-in-bag" chemical pads, the "side-by-side" pads use a breakable seal that is placed between two compartments, each of which contains one of the reagents. These pads try to use a strong outer seal around the perimeter of the bag and a weak inner seal between the two compartments. However, this is difficult to achieve in a Consistent base and any tearing of the outer seal can cause a trickle of reagents in the user.

As such, there continues to be a need for therapeutic pads that are easy to use and achieve consistent heating to a desired body part.

Synthesis of the Invention According to an embodiment of the present invention, a therapeutic kit is disclosed comprising a pad defining a cavity and a thermal insert that is capable of being removably positioned within the cavity. The thermal insert comprises a substrate containing an exothermic coating. The exothermic coating comprises a metal that is oxidized. The exothermic coating is activated upon exposure of the exothermic coating with oxygen and moisture to generate heat.

According to another embodiment of the present invention, a method for providing heat to a body part is described. The method comprises providing a thermal insert containing an exothermic coating, wherein the thermal insert is sealed within an enclosure that exhibits the oxygen path to the exothermic coating. The enclosure is open and placed inside a cavity defined by a pad. The pad is placed adjacent to or near a part of the body.

Other features and aspects of the present invention are described in more detail below.

Brief Description of the Drawings A complete and capable description of the present invention, which includes the best mode thereof, addressed to one of ordinary skill in the art, is disclosed more particularly in the remainder of the application, which refers to the figures appended hereto. which: Figure 1 illustrates a cross-sectional view of an embodiment of a thermal insert of the present invention; Figure 2 illustrates a cross-sectional view of another embodiment of a thermal insert of the present invention; Y Figure 3 is a top view of an embodiment of a therapeutic kit of the present invention; Figure 4 is a bottom view of the set of Figure 3; Figure 5 is a cross-sectional view of Figure 3 taken along line 5-5; Figure 6 is a perspective view of the pad of Figure 3 placed on an arm; Y Figure 7 illustrates the thermal response curve showing the temperature (° C) versus the time (minutes) for the sample of Example 2.

Detailed Description of Representative Incorporations Definitions As used herein the term "nonwoven fabric or fabric" means a fabric having a structure of individual threads or fibers which are interlaced, but not in an identifiable manner as in a knitted fabric. Fabrics or non-woven fabrics have been formed from many processes such as, for example, meltblowing processes, spinning processes, carded and bonded weaving processes, etc. As used herein, the term "meltblowing" refers to a process in which the fibers are formed by extruding a molten thermoplastic material through a plurality of capillary vessels, usually circular as fibers fused in streams (for example air) of gas at high speed converging that attenuate the fibers of molten thermoplastic material to reduce their diameter, which can be a microfiber diameter. Then, the meltblown fibers are transported by the high velocity gas stream and are deposited on a collection surface to form a randomly dispersed meltblown fabric. Such a process is described, for example, in United States of America Patent No. 3,849,241 issued to Butin et al., Which is incorporated herein in its entirety by reference thereto for all purposes. Generally speaking, melt blown fibers are microfibers that can be continuous or discontinuous, are generally smaller than 10 microns in diameter, and are generally sticky when deposited on a collection surface.

As used herein, the term "spunbonded" refers to a process in which small diameter substantially continuous fibers are formed by extruding a molten thermoplastic material from a plurality of usually circular, fine capillary vessels of a spinner member. with the diameter of the extruded fibers then being rapidly reduced as by, for example, the eductive pull and / or other well-known spinning linkage mechanisms. The production of non-woven fabrics linked by spinning is described and illustrated, for example, in U.S. Patent Nos. 4,340,563 issued to Appel et al .; 3,692,618 granted to Dorschner and others; 3,802,817 granted to Matsuki and others; 3,338,992 granted to Kinney; 3,341,394 granted to Kinney; 3,502,763 awarded to Hartman; 3,502,538 awarded to Levy; 3,542,615 granted to Dobo and others; and 5,382,400 granted to Pike and others, which are hereby incorporated in their entirety by reference thereto for all purposes. Spunbonded fibers are generally non-tacky when they are deposited on a collection surface. Spunbonded fibers can sometimes have diameters of less than about 40 microns, and are often between about 5 and about 20 microns.

As used herein, the term "coform" generally refers to composite materials comprising a stabilized blend or binder of thermoplastic fibers and a second non-thermoplastic material. As an example, coform materials can be made by a process in which at least one melt blown die head is arranged near a channel through which other materials are added to the fabric while it is being formed. Such other materials may include, but are not limited to, fibrous organic materials such as non-wood or wood pulp such as cotton, rayon, recycled paper, pulp fluff and also super-absorbent particles. organic absorbent materials and / or inorganic, the polymeric basic fibers treated and so on. Some examples of such coform materials are described in U.S. Patent Nos. 4,100,324 issued to Anderson et al .; 5,284,703 granted to Everhart and others; and 5,350,624 granted to Georger and others; which are incorporated herein in their entirety by reference thereto for all purposes.

As the terms "extensible" or "extensibility" generally refers to a material that stretches or extends in the direction of a force applied at least about 50% of its width or relaxed length. An extensible material does not necessarily have recovery properties. For example, an elastomeric material is an extensible material having recovery properties. A melt blown fabric may be extensible, but not have recovery properties, and therefore, be a non-stretchable, stretchable material.

As used herein, the term "elastomeric" and "elastic" refers to a material that, upon application of a stretching force, is stretchable in at least one direction (such as the cross machine direction), and the which at the release of the stretching force, contracts / returns to approximately its original direction. For example, a stretched material may have a stretched length that is at least less 50% greater of its length without relaxed stretching, and which may recover up to at least 50% of its stretched length upon release of the stretching force. A hypothetical example may be a one (1) inch sample of a material that is stretchable to at least 1.50 inches and which, upon release of the drawing force, may be recovered to a length of no more than 1.25 inches. Desirably, such elastomeric sheet contracts or recovers at least 50%, and even more desirably, at least 80% of the stretched length in the cross machine direction.

As used here, the "water vapor transmission rate" (WVTR) generally refers to the rate at which water vapor penetrates through a material as measured in units of grams per square meter per 24 hours ( g / m2 / 24 hrs.). The test used to determine the water vapor transmission rate of a material can vary based on the nature of the material. For example, in some embodiments, the water vapor transmission rate can be determined generally in accordance with ASTM Standard E-96E-80. This test may be particularly appropriate for materials that are believed to have a water vapor transmission rate of up to about 3,000 grams per square meter per 24 hours. Another technique to measure the water vapor transmission rate involves the use of a PERMATRAN-100K water vapor penetration analysis system, in which it is commercially available from Modern Controls, Inc. from Minneapolis, Minnesota. Such a system may be particularly well suited for materials that are believed to have a water vapor transmission rate of greater than about 3,000 grams per square meter per 24 hours. However, as is well known in the art, other systems and techniques can also be used to measure the water vapor transmission rate.

As used herein, the term "breathable" means permeable to water vapor and gases, but impermeable to liquid water. For example, "breathable barriers" and "breathable films" allow water vapor to pass through them, but are substantially impervious to liquid water. "Breathing ability" of a material that is measured in terms of the water vapor transmission rate (WVTR), with higher values representing more than one vapor permeable material and internal values representing a lower vapor permeable material. Breathable materials can, for example, have a water vapor transmission rate (WVTR) of at least about 100 grams per square meter per 24 hours (g / m2 / 24 hrs.), in some incorporations from around 500 to about 20,000 grams per square meter per 24 hours, and in some additions, from about 1,000 to about 15,000 grams per square meter per 24 hours.

Detailed description Reference may now be made in detail to several embodiments of the invention, one or more examples of which are disclosed below. Each example is provided by way of explanation, not limitation of the invention. In fact, it may be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. For example, the features illustrated or described as part of an embodiment may be used in another embodiment to still yield a further embodiment. Therefore, it is the intention that the present invention cover such modifications and variations.

Generally speaking, the present invention is directed to a therapeutic set configured to provide heat to an area of the body. The therapeutic game can be used to treat a variety of injuries to muscles, ligaments, tendons, etc., including the arms, legs, ankles, knees, shoulders, feet, necks, backs, elbows, wrists, hands, breasts, fingers, toes, and so on. Regardless of intended use, therapeutic play generally employs a pad that is capable of receiving a thermal insert. The thermal insert includes a substrate that It contains an exothermic coating that is capable of generating heat in the presence of oxygen and moisture. A particular benefit and the thermal insert of the present invention is that it is disposable. Therefore, when the thermal insert exhausts its ability to produce heat, a new insert can simply be used in the game. This allows for continued use of the pad, which results in substantial cost savings to the consumer.

The pad used in the therapeutic kit of the present invention can be formed in a variety of ways as is known in the art. For example, the pad may contain an extensible material that is generally conformable to a part of the body of interest and capable of providing a user with a comfortable fit without restricting blood flow. Any type of extensible material can be used for this purpose. For example, the extensible material can be a nonwoven fabric, a woven fabric, a knitted fabric, a paper, a film, a foam, etc. When used, the non-woven fabric may be a spunbonded fabric (perforated or non-perforated), a meltblown fabric, a bonded carded fabric, an airlaid fabric, a coform fabric, a hydraulically entangled fabric, and so on Suitable polymers for making non-woven fabrics include, for example, polyolefins, polyesters, polyamides, polycarbonates, copolymers and mixtures thereof, etc. Suitable polyolefins include polyethylene, such as high density polyethylene, low density polyethylene, lower density polyethylene, and linear lower density polyethylene; polypropylene, such as isotactic polypropylene, such as atactic polypropylene, and syndiotactic polypropylene; polybutylene, such as poly (1-butene) and poly (2-butene); polypentene, such as poly (1-pentene) and poly (2-pentene); poly (3-methyl-1-pentene); and poly (4-methyl-1-pentene); and the copolymers and mixtures thereof. Suitable copolymers include block and random copolymers prepared from two or more different unsaturated olefin monomers, such as ethylene / propylene and ethylene / propylene copolymers. Suitable polyamides include nylon 6, nylon 6/6, nylon 4/6, nylon 11, nylon 12, nylon 6/10, nylon 6/12, nylon 12/12, copolymers of caprolactam and the alkylene oxide diamine, etc., as well as the mixtures and copolymers thereof. Suitable polyesters include poly (lactide) and polylactic acid polymers as well as polyethylene terephthalate, the polybutylene terephthalate, the polytetramethylene terephthalate, and the polycyclohexylene-1,4-dimethylene terephthalate and the isophthalate copolymers thereof, as well as the mixtures thereof. It should be noted that the polymer (s) may also contain other additives, such as processing aids or treatment compositions to impart the desired properties to the fibers, residuals of solvents, pigments or dyes, and so on.

If desired, the extensible material may also contain an elastomeric polymer, such as elastomeric polyesters, elastomeric polyurethanes, elastomeric polyamides, elastomeric polyolefins, and elastomeric copolymers, and so forth. Examples of elastomeric copolymers include block copolymers having the general formula ABA 'or AB, wherein A and A' are each end blocks of thermoplastic polymer containing a styrenic moiety (eg, poly (vinyl arene)) and wherein B is a middle block of elastomeric polymer, such as a conjugated diene or a lower alkene polymer (e.g., polystyrene-poly (ethylene-polybutylene) -polystyrene block copolymers). Also suitable are polymers composed of an ABAB tetrablock copolymer, as described in U.S. Patent No. 5,332,613 issued to Taylor et al., Which is hereby incorporated by reference in its entirety for all. purposes. An example of such a tetrablock copolymer is a styrene-poly (ethylene-propylene) -styrene-poly (ethylene-propylene) block copolymer ("S-EP-S-EP"). Commercially available copolymers A-B-A 'and A-B-A-B include several different formulations of Kraton Polymers of Houston, Texas under the trademark designation KRATON®. The KRATON® block copolymers are available in several different formulations, a number of which are identified in US Pat. Nos. 4,663,220; 4,323,534; 4,834,738; 5,093,422 and 5,304,599, which are herein incorporated in their entirety by reference thereto for all purposes. Other commercially available block copolymers include the S-EP-S or styrene-poly (ethylene-propylene) -styrene elastomeric copolymer available from Kuraray Company, Ltd., of Okayama, Japan, under the brand name SEPTEON®.

Examples of elastomeric polyolefins include polyethylenes and ultra low density elastomeric polypropylenes, such as those produced by "metallocene" or "single site" catalyst methods. Such elastomeric olefin polymers are commercially available from ExxonMobil Chemical Co. from Houston, Texas under the brand designations ACHIEVE® (polypropylene-base), EXACT® (ethylene-base), and EXCEED® (ethylene-base). The elastomeric olefin polymers are also commercially available from DuPont Dow Elastomers, LLC (a joint venture between DuPont and Dow Chemical Co.) under the trademark designation ENGAGE® (ethylene-base) and AFFINITY® (ethylene-base). Examples of such polymers are also described in U.S. Patent Nos. 5,278,272 and 5,272,236 issued to Lai et al., Which are hereby incorporated by reference in their entirety for all purposes. Also useful are certain elastomeric polypropylenes, as described in U.S. Patent Nos. 5,538,056 issued to Yang et al. and 5,596,052 issued to Resconi et al., which are hereby incorporated by reference in their entirety for all purposes.

The extensible material may also contain a film that is impervious to vapor and liquid, permeable to vapor and liquid, or impervious to liquid but vapor permeable (eg, "breathable"). The film can be formed of a polyolefin polymer, such as a linear low density polyethylene (LLDPE) or polypropylene. Examples of predominantly linear polyolefin polymers include, without limitation, the polymers produced from the following monomers: ethylene, propylene, 1-butene, 4-methyl-pentene, 1-hexene, 1-octene and higher olefins as well as the copolymers and the terpolymers of the previous ones. Additionally, copolymers of ethylene and other polyolefins include butene, 4-methyl-pentene, hexene, heptene, octene, decene, etc., are also examples of predominantly linear olefin polymers. The film may also contain an elastomeric polymer, as previously described.

The extensible material may also have a multiple layer structure. Suitable multi-layer materials may include, for example, laminates spunbonded / blown with fusion / spunbonded (SMS) and laminates linked by spinning / blowing with fusion (YE) . Several examples of spin-linked / meltblown / spin-bonded laminates are described in US Pat. Nos. 4,041,203 to Brock et al .; 5,213,881 granted to Timmons and others; 5,464,688 granted to Timmons and others; 4,334,888 granted to Bornslaegger; 5,169,706 granted to Collier and others; and 4,766,029 granted to Brock and others, which are hereby incorporated in their entirety by reference thereto for all purposes. Additionally, commercially available spunbonded / meltblown / spin-bonded laminates can be obtained from Kimberly-Clark Corporation under the designations Spunguard® and Evolution®.

Multiple-layer elastic laminates can also be used in the extensible material. The elastic laminate may, for example, include a film bonded to a non-woven fabric. A suitable elastic laminate is a bonded bonded laminate, which may contain a narrow nonwoven fabric bonded to an elastic film. Some examples of bonded bonded laminates are described in U.S. Patent Nos. 5,226,992; 4,981,747; 4,965,122; and 5,336,545, all granted to Morman, which are hereby incorporated in their entirety by reference thereto for all purposes. Another suitable elastic laminate is a stretched attached laminate, which may contain a nonwoven fabric that is attached to an elastic film in an extended condition. Proper stretched bonded laminate is described in U.S. Patent Nos. 4,720,415 issued to Vander Wielen et al .; 5,385,775 granted to Wright; 4,789,699 granted to Kieffer and others; 4,781,966 granted to Taylor; 4,657,802 granted to Morman; and 4,655,760 granted to Morman and others, which are hereby incorporated in their entirety by reference thereto for all purposes. The elastic laminate may also be a narrow stretch bonded laminate. Examples of tapered stretched joined laminates are described in U.S. Patent Nos. 5,114,781 and 5,116,662 which are both incorporated herein by reference in their entirety for all purposes.

As previously mentioned, the pad of the present invention is capable of receiving a thermal insert to provide heat to a desired body part. In some embodiments, for example, the pad defines a cavity in which the thermal insert may be removably positioned. The size and shape of the cavity are configured to accommodate the thermal insert. If desired, the cavity can be formed from a separate receptacle (eg, pocket, pouch, etc.) which is attached to the extensible material with sewing, adhesive, thermal bonds, etc. Such a receptacle can be formed of an extensible material that can be conform to the thermal insert and therefore help prevent its removal without intention. Once placed within the cavity, the pad can then be placed adjacent to or close to a part of the body to impart the desired level of heat. In some cases, the pad can be turned around the body part and held so that the heat can be imparted without requiring the user to grasp the pad.

Referring to Figures 3 to 6, several embodiments of a therapeutic set 200 can now be described in greater detail. In this particular embodiment, the kit 200 includes a pad 202 which is formed of an expandable material 203 and is configured to wrap around a user's arm. A base 210 is attached to the extensible material 203 that can be formed of a material that is sufficiently flexible to allow normal functional movement of areas not associated with the specifically treated area., but which is not extensible enough to provide pressure, compression, and / or support to a treated area. For example, the base 210 can be formed of a mild polymeric material. The base 210 can be attached to the extensible material 203 in any desired manner, such as using seams, adhesives, thermal bonds, etc. The curls 204A and 204B are also attached to the outer edges of the base 210. The extensible material 203 is capable of being inserted through the friezes 204A and 204B to join the pad 202 to a part of the body. Although not required, curls 204A and 204B are typically formed of a hard polymeric material. The pad 202 also includes fasteners 208 and 214 and (e.g., hook and curl, push buttons, buttons, tape, etc.). The fasteners 208 and 214 may be brought together to inhibit loosening of the extensible material 203 during use. In this particular embodiment, the pad 202 also includes a receptacle 206 which is attached to the extensible material 203 and defines a cavity 217 for receiving a thermal insert 212 (FIG. 5). The cavity 217 can be formed by joining three sides of the receptacle 206 to the extensible material 203 so that the thermal insert 212 is received through the fourth unbonded side. The unbonded side may have a fastener, such as snap buttons, buttons, hook and loop fasteners, etc., to help close and seal the cavity 217 upon receipt of the heat insert 212. Although only one side is described as which is unattached in this embodiment, it should be understood that one or more other sides may also be unattached to receive the thermal insert 212. Such unbound side (s) in the same manner employ (n) a bra, as previously described.

To apply the pad 202 to a specific area, the end of the expandable material 203 located closest to the fastener 208 is wrapped around the desired area and fed through the curl 204A. This allows the initial placement of the extensible material 203 and application of some pressure to the treated area. After passing through loop 204A, expandable material 203 is wrapped back down the area and fed through loop 204B. By pulling the extensible material 203 through the curl 204B, the thermal insert 212 is directly pressed down into the desired area. Then, the extendable material 203 is pulled tight and secured in place using fasteners 208 and 214.

The thermal insert of the present invention generally contains an exothermic coating that is capable of generating heat in the presence of moisture and oxygen. The exothermic coating can be formed from a variety of different components, including the metals that are oxidized, the carbon components, the binders, the electrolytic salts, and so on. Examples of such metals include, but are not limited to, iron, zinc, aluminum, magnesium, and so forth. Although not required, the metal can be initially supplied in powder form to facilitate handling and to reduce costs. Various methods for removing impurities from a crude metal (eg iron) to form a powder include, for example, wet processing techniques, such as solvent extraction, ion exchange, and electrolytic refining for separation of elements. metallic; the processing with hydrogen gas (H2) for the removal of gaseous elements, such as oxygen and nitrogen; the refining method of floating zone casting. Using such techniques, the purity of the metal can be at least about 95%, in some embodiments at least about 97%, and in some embodiments, at least about 99%. The size of the metal powder particle can also be less than about 500 microns, in some embodiments less than about 100 microns, and in some embodiments, less than about 50 microns. The use of such small particles can improve the contact surface of metal with air, thereby improving the possibility and efficiency of the desired exothermic reaction. The concentration of metal powder employed will generally vary depending on the nature of the metal powder, and the desired extent of the exothermic reaction / oxidation. In most embodiments, the metal powder is present in the exothermic coating in an amount from about 40% by weight to about 95% by weight. In some embodiments from about 50% by weight to about 90% by weight, and in some embodiments, from about 60% by weight to about 80% by weight.

In addition to a metal that is oxidized, a carbon component can also be used in the exothermic coating of the present invention. Without intending to be limited in theory, it is believed that such a carbon component promotes the oxidation reaction of the metal and acts as a catalyst to generate heat. The carbon component can Be activated carbon, carbon black, graphite, and so on. When used, activated carbon can be formed from sawdust, wood, coal, peat, lignite, bituminous coal, coconut shells, etc. Some suitable forms of activated carbon and techniques for forming them are described in US Pat. Nos. 5,693,385 issued to Park; 5,834,114 granted to Economy and others; 6,517,906 granted to Economy and others; 6,573,212 issued to McCrae et al., as well as in the United States Patent Application Publications Nos. 202/0141961 issued to Falat et al., and 2004/0166248 issued to Hu and others, all of which are incorporated herein in their entirety by reference thereto for all purposes.

The exothermic coating may also employ a binder to improve the durability of the coating when applied to a substrate. The binder can also serve as an adhesive to bond a substrate to another substrate. Generally speaking, any of a variety of binders can be used in the exothermic coating of the present invention. Suitable binders may include, for example, those that become insoluble in water upon interlacing. The interlacing can be achieved in a variety of ways, including by reacting the binder with a polyfunctional interlacing agent. Examples of such entangled agents include, but are not limited to, the melamine-formaldehyde urea dimethylol, urea-formaldehyde, polyamide epichlorohydrin, etc.

In some embodiments, a polymer latex can be used as the binder. The polymer suitable for use in latexes typically has a glass transition temperature of about 30 ° C or less so that the flexibility of the resulting substrate is not substantially restricted. Moreover, the polymer typically also has a glass transition temperature of about -25 ° C or more to minimize stickiness of the polymer latex. For example, in some embodiments, the polymer has a glass transition temperature of about -15 ° C to about 15 ° C, and in some embodiments, from about -10 ° C to about 0 ° C. For example, some suitable polymer latexes that can be used in the present invention can be based on polymers such as, but not limited to, styrene-butadiene copolymers, polyvinyl acetate homopolymers, ethylene vinyl copolymers acetate, vinyl acetate acrylic copolymers, ethylene-vinyl chloride copolymers, ethylene-vinyl chloride-vinyl acetate terpolymers, polyvinyl acrylic chloride copolymers, acrylic polymers, nitrile polymers, and any other suitable anionic polymer latex polymers known in the art. The loading of the polymer latexes described above can be easily varied, as is well known in the art, by using a stabilizing agent having the desired filler during the preparation of the polymer latex. The specific techniques for a carbon / polymer latex system are described in greater detail in U.S. Patent No. 6,573,212 issued to McCrae et al. The carbon latex / activated polymer systems that can be used in the present invention include the Nuchar® PMA, the DPX-8433-68A, and the DPX-8433-68B, all of which are available from MeadWestvaco Corp. of Stamford , Connecticut.

If desired, the polymer latex can be entangled using any technique known in the art, such as by heating, ionization, etc. Preferably, the polymer latex is self-entangled in which the external entangled agents (e.g. , N-methylol acrylamide) are not required to induce entanglement. Specifically, the interlacing agents can lead to the formation of bonds between the polymer latex and the substrate to which it is applied. Such a union can sometimes interfere with the effectiveness of the substrate in generating heat. Therefore, the polymer latex can be substantially free of interlacing agents. Particularly suitable self-interlacing polymer latexes are the ethylene-vinyl acetate copolymers available from Celanese Corp. of Dallas, Texas under the designation DUR-0-SET® Elite (e.g., PE-25220A). Alternatively, an inhibitor can simply be used that reduces the extent of interlacing, such as free radical scavengers, methyl hydroquinone, t-butylcatechol, agents that control pH (eg, potassium hydroxide), etc.

Although polymer latexes can be effectively used as binders in the present invention, such compounds sometimes result in a reduction in drapery and an increase in residual odor. Therefore, the present inventor has discovered that water-soluble organic polymers can also be used as binders, either alone or in conjunction with polymer latexes, to alleviate such concerns. For example, one class of water-soluble organic polymer that is suitable in the present invention is the polysaccharide and derivatives thereof. Polysaccharides are polymers containing repeated carbohydrate units, which may be cationic, ionic, nonionic, and / or amphoteric. In a particular embodiment, the polysaccharide is a nonionic, cationic, anionic, and / or amphoteric cellulosic ether. The nonionic cellulose ethers can include, but are not limited to alkyl cellulose ethers, such as methyl cellulose and ethyl cellulose; the hydroxyalkyl cellulose ethers, such as hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxybutyl hydroxybutyl cellulose, hydroxyethyl hydroxypropyl cellulose, hydroxybutyl hydroxyethyl cellulose and hydroxybutyl cellulose. hydroxyethyl hydroxypropyl; the hydroxyalkyl alkyl cellulose ethers, such as methyl hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl ethyl cellulose, hydroxypropyl ethyl cellulose, methyl ethyl hydroxyethyl cellulose and methyl ethyl hydroxypropyl cellulose; and so on.

Suitable cellulose ethers may include, for example, those available from Akzo Nobel of Stamford, Connecticut under the name "BERMOCOLL". Still other suitable cellulosic ethers are those available from Shin-Etsu Chemical Co. , Ltd. of Tokyo, Japan under the name "METOLOSE", which include METOLOSE Type SM (methylcellulose), METOLOSE Type SH (hydroxypropylmethyl cellulose), and METOLOSE Type SE (hydroxyethylmethyl cellulose). A particular example of a suitable non-ionic cellulosic ether is methylcellulose having a degree of methoxy substitution (DS) of 1.8. The degree of methoxyl substitution represents the average number of hydroxyl groups present in each anhydroglucose unit that have been reactivated, which may vary between 0 and 3. One such cellulose ether is METOLOSE SM-100, which is a commercially available methylcellulose from Shin-Etsu Chemical Co. , Ltd .. Other suitable cellulose ethers are also available from Hercules, Inc. of Wilmington, Delaware under the name "CULMINAL".

The concentration of the carbon component and / or binder in the exothermic coating can generally vary for based on the desired properties of the substrate. For example, the amount of carbon component is generally custom-made to facilitate the oxidation / exothermic reaction without adversely affecting other properties of the substrate. Typically, the carbon component is present in the thermal coating in an amount of from about 0.01% by weight to about 20% by weight, in some embodiments from about 0.1% by weight to about 15% by weight, and in some embodiments, from about 1% by weight to about 12% by weight. Additionally, although relatively higher binder concentrations may provide better physical properties for the exothermic coating, they may in the same way have an adverse effect on other properties, such as the absorption capacity of the substrate to which it is applied. Conversely, relatively lower binder concentrations may reduce the ability of the exothermic coating to remain fixed on the substrate. Therefore, in most embodiments, the binder is present in the exothermic coating in an amount of about 0.01% by weight to about 20% by weight, in some embodiments from about 0.1% by weight to about 10% by weight, and in some incorporations, from around 0.5% by weight to around 8% by weight.

Still other components can also be employed in the exothermic coating of the present invention. For example, as is well known in the art, an electrolytic salt can be used to react with and remove any layer (s) of pacifying oxide (s) that may otherwise prevent the metal from rusting. Suitable electrolyte salts may include, but are not limited to, sulfates or alkyl halides, such as sodium chloride, potassium chloride, etc .; sulfates or alkylene halides, such as calcium chloride, magnesium chloride, etc., and so on. When employed, the electrolytic salt is typically present in the exothermic coating in an amount of from about 0.01% by weight to about 10% by weight, in some embodiments from about 0.1% by weight to about 8% by weight, and in some embodiments, from about 1% by weight to about 6% by weight.

Additionally, the particles can also be used in the exothermic coating that act as humility retainers. That is, prior to the oxidation / exothermic reaction, these particles can retain moisture. However, after the reaction has proceeded to a certain extent and the moisture concentration is reduced, the particles can release moisture to allow the reaction to continue. In addition to acting as a moisture retainer, the particles can also provide other benefits to the exothermic coating of the present invention. For example, the particles may alter the black color normally associated with the carbon component and / or metal powder. When used, the size of the particles retaining moisture may be less than about 500 micrometers, in some embodiments less than about 100 micrometers, and in some embodiments, less than about 50 micrometers. In the same way, the particles can be porous. Without intending to be limited by theory, it is believed that the porous particles can provide a path for air and / or water vapors to better contact the metal powder. For example, the particles may have pores / channels with an average diameter of greater than about 5 angstroms, in some incorporations greater than about 20 angstroms, and that in some embodiments, greater than about 50 angstroms. The surface area of such films can also be greater than about 15 square meters per gram, in some additions greater than about 25 square meters per gram, and in some additions, greater than about 50 square meters per gram. The surface area can be determined by the physical gas absorption method (B.E.T.) of Bruanauer, Emmet, and Teller,. Journal of the Amerina Chemical Society, Vol. 60, 1938, Pá. 309, with nitrogen as the absorption gas.

In a particular embodiment, porous carbonate particles (eg, calcium carbonate) are used to retain moisture and also to alter the black color normally associated with activated carbon and / or metal powder. Such a color change may be more aesthetically pleasing to a user, particularly when the coating is employed on substrates designed for consumer / personal use. Suitable white calcium carbonate particles are commercially available in both dry forms and aqueous slurry from Omya, Inc. of Proctor, Vermont. Still other suitable inorganic particles that can retain moisture include, but are not limited to, the silicates, such as calcium silicate, alumina silicates (e.g., mica powder, clay, etc.), magnesium silicates ( for example, talcum), quartzite, calcium silicate fluorite, vermiculite, etc .; the alumina; the silica; and so on. The concentration of the particles can generally vary depending on the nature of the particles, and the desired extension of the exothermic reaction and the alteration of color. For example, the particles may be present in the exothermic coating in an amount of from about 0.01% by weight to about 30% by weight, in some embodiments from about 0.1% by weight to about 20% by weight, and in some additions, from around 1% by weight to around 15% by weight.

In addition to the aforementioned components, other components, such as surfactants, pH adjusters, dyes / pigments / inks, viscosity modifiers, etc., may also be included in the exothermic coating of the present invention. The viscosity modifiers can be used, for example, to adjust the viscosity of the coating formulation based on the desired coating process and / or the performance of the coated substrate. Suitable viscosity modifiers include gums, such as xanthan gum. Binders, such as cellulose ethers, can also function as appropriate viscosity modifiers. When employed, such additional components typically constitute less than about 5% by weight, in some embodiments less than about 2% by weight, and in some embodiments, from about 0.001% by weight to about 1% of the exothermic coating .

Despite the manner in which it is formed, the exothermic coating is applied to a substrate, which can perform other functions of the thermal insert or simply act as a physical conveyor for the coating. Any type of substrate can be applied with the exothermic coating according to the present invention. For example, non-woven fabrics, woven fabrics, knitted fabrics, paper fabrics, films, foams, etc., can be applied with the exothermic coating. Typically, the polymers used to form the substrate have a melting or softness temperature that is higher than the temperature necessary to evaporate moisture. One or more components of such polymers can have, for example, a softness temperature of from about 100 ° C to about 400 ° C, in some embodiments from about 110 ° C to about 300 ° C, and in some incorporations, from around 120 ° C to around 250 ° C. Examples of such polymers may include, but are not limited to, synthetic polymers (e.g., polyethylene, polypropylene, polyethylene terephthalate, nylon 6, nylon 66, KEVLAR ™, syndiotactic polystyrene, polyesters crystalline liquids, etc.); cellulosic polymers (soft wood pulp, hardwood pulp, thermomechanical pulp, etc.); the combinations thereof; and so on .

To apply the exothermic coating of the present invention to a substrate, the components can initially be dissolved or dispersed in a solvent. For example, one or more of the aforementioned components can be mixed with a solvent, either sequentially or simultaneously, to form a coating formulation that can be easily applied to a substrate. Any solvent capable of dispersing or dissolving the components is appropriate, for example water; alcohols such as ethanol or methanol; dimethylformamide; dimethyl sulfoxide; hydrocarbons such as pentane, butane, heptane; hexane, toluene and xylene; ethers such as diethyl ether and tetrahydrofuran; ketones and aldehydes such as acetone and methyl ethyl ketone; acids such as acetic acid and formic acid; and halogenated solvents such as dichloromethane and carbon tetrachloride; as well as the mixtures thereof. In a particular embodiment, for example, water is used as the solvent for an aqueous coating formulation to be formed. The concentration of the solvent is generally high enough to inhibit oxidation of the metal before use. Specifically, when it is present in a sufficiently high concentration; The solvent can act as a barrier to prevent air from prematurely contacting the metal that is oxidized. If the amount of solvent is very small, however, the exothermic reaction may occur prematurely. In the same way, if the amount of solvent is very large, the amount of metal deposited on the substrate may be too low to provide the desired exothermic effect. Although the current concentration of solvent (e.g., water) employed may generally depend on the type of metal being oxidized and the substrate on which it is applied, it is nevertheless typically present in an amount of 10 of about 10% by weight up to around 80% by weight, in some incorporations from around 20% by weight to around 70% by weight, and in some incorporations, from about 25% weight to about 60% by weight of the coating formulation.

The amount of the other components added to the coating formulation can vary depending on the amount of heat desired, the wet pickup of the application method used, etc. For example, the amount of metal that is oxidized (in powder form) within the coating formulation is generally in the range from about 20% by weight to about 80% by weight, in some embodiments from about 30% by weight up to about 70% by weight, and in some embodiments, from about 35% by weight to about 60% by weight. Additionally, the carbon component can constitute from about 0.1% by weight to about 20% by weight, in some embodiments from about 0.1% by weight to about 15% by weight, and in some embodiments, from about 0.2. % by weight to about 10% by weight of the coating formulation. Binders can range from about 0.01% by weight to about 20% by weight, in some embodiments from about 0.1% by weight to about 15% by weight, and in some embodiments, from about 1% by weight to about 10% by weight of the coating formulation. Electrolytic salts can range from about 0.01% by weight to about 10% by weight, in some incorporations from about 0.1% by weight to about 8% by weight, and in some embodiments, from about 1% by weight to about 5% by weight of the coating formulation. In addition, moisture retaining particles (eg, calcium carbonate) can constitute from about 2% by weight to about 30% by weight, in some embodiments from about 3% by weight to about 25% by weight, and in some embodiments, from about 4% by weight 10% by weight of the coating formulation. Other components, such as surfactants, pH adjusters, viscosity modifiers, etc., can also constitute from about 0.001% by weight to about 5% by weight, in some embodiments from about 0.01% weight to about of 1% by weight, and in some embodiments from about 0.02% by weight to about 0.5% by weight of the coating formulation.

The solids content and / or viscosity of the coating formulation can be varied to achieve the desired amount of heat generation. For example, the coating formulation can have a solids content of from about 30% to about 80%, in some embodiments from about 40% to about 70%, and in some embodiments, from about 50% to around 60%. By varying the solids content of the coating formulation, the presence of metal powder and other components in the coating can be controlled exothermic. For example, to form an exothermic coating with a higher level of metal powder, the coating formulation can be provided with a relatively high solids content so that a greater percentage of the metal powder is incorporated into the exothermic coating during the process of application. Additionally, the viscosity of the coating formulation may also vary depending on the coating method and / or the type of binder employed. For example, lower viscosities can be used for saturation coating techniques (eg, submerged coating), and while higher viscosities can be used for drop coating techniques. Generally, the viscosity is less than about 2 X 106 centipoise, in some embodiments less than about 2 X 105 centipoise, in some additions less than about 2 X 104 centipoise, and in some additions, less than about 2 X 103 centipoises, as measured with a Brookfield DV-1 viscometer with an LV spindle. If desired, the thickeners or other viscosity modifiers can be employed in the coating formulation to increase or decrease the viscosity.

The coating formulation can be applied to a substrate using any conventional technique, such as bar, roll, knife, curtain, print techniques (for example, rotogravure), spray, dye with slot, fall coating, or coating with submerged. The materials forming the substrate of (for example, fibers) can be coated, for example before and / or after incorporation into the substrate. The coating can be applied on one or both surfaces of the substrate. For example, the exothermic coating may be present on a surface of the substrate that is opposite that coating of the user or carrier to avoid the possibility of burning. In addition, the coating formulation can cover a complete surface of the substrate, or it can only cover a part of the substrate. When the exothermic coating is applied to multiple surfaces, each surface can be coated sequentially or simultaneously.

Despite the manner in which the coating is applied, the resulting substrate is typically heated to a certain temperature to remove the solvent and any moisture from the coating. For example, the substrate can be heated to a temperature of at least about 100 ° C, in some additions to at least about 110 ° C, and in some additions, to at least about 120 ° C. In this manner, the resultant dry exothermic coating is anhydrous, for example, generally free of water. By minimizing the amount of moisture, the exothermic coating is less able to react prematurely and generate heat. That is, the metal that is oxidized usually does not react with oxygen unless something of a minimal amount of water is I presented. Therefore, the exothermic coating can remain inactive until it is placed in the vicinity of moisture (eg, next to a layer containing moisture) during use. It should be understood, however, that relatively small amounts of water may still be present in the exothermic coating without causing a substantial exothermic reaction. In some embodiments, for example, in the exothermic coating it contains water in an amount less than about 0.5% by weight, in some incorporations less than about 0.1% by weight, and in some embodiments, less than about 0.01% by weight .

The level of aggregate solids of the exothermic coating can also be varied as desired. The "level of aggregate solids" is determined by subtracting the weight of the untreated substrate from the weight of the treated substrate (after drying), dividing this weight calculated by the weight of the untreated substrate, and then multiplying it by 100%. Lower aggregate levels can optimize certain properties (eg, absorbency), while higher aggregate levels can optimize heat generation. In some additions, for example, the aggregate level is from around 100% to around 5000%, in some incorporations from around 200% to around 2400%, and in some incorporations, from around 400% to around 1200%. The thickness of the Exothermic coating may also vary. For example, the thickness may be in the range from about 0.01 millimeters to about 5 millimeters, in some additions, from about 0.01 millimeters to about 3 millimeters, and in some additions, from about 0.1 millimeters to about 2 millimeters. millimeters In some cases, a relatively thin coating may be employed (for example, from about 0.01 millimeters to about 0.5 millimeters). Such a thin coating can improve the flexibility of the substrate, while still providing uniform heat.

To maintain porosity, flexibility, and in some cases other characteristics of the substrate, it may sometimes be desirable to apply the exothermic coating to cover less than 100%, in some embodiments from about 10% to about 80%, and in some additions, from about 20% to about 60% of the area of one or more substrate surfaces. For example, in a particular embodiment, the exothermic coating is applied to the substrate in a previously selected pattern (for example, reticular pattern, grille in the form of diamonds, points, and so on). Although not required, such patterned exothermic coating can provide sufficient heating to the substrate without covering a substantial part of the surface area of the substrate. This may be desired to optimize flexibility, absorbency, and other characteristics of the substrate. It should be understood, however, that the coating can also be uniformly applied to one or more surfaces of the substrate. Additionally, a patterned exothermic coating can also provide different functionality to each zone. For example, in one embodiment, the substrate is treated with two or more patterns of coated regions that may or may not overlap. The regions can be on the same or on different surfaces of the substrate. In one embodiment, one region of a substrate is coated with a first exothermic coating, while another region is coated with a second exothermic coating. If desired, one region may provide a different amount of heat than another region.

In addition to having functionality benefits, the substrate can also have several aesthetic benefits as . For example, although it contains activated carbon, the substrate can be made without the black color commonly associated with activated carbon. In one embodiment, the lightly colored or white particulates (eg, calcium carbonate, titanium dioxide, etc.) are employed in the exothermic coating so that the resulting substrate has a blue or grayish color. Additionally, various pigments, dyes, and / or inks can be employed to alter the color of the exothermic coating. The substrate can also be applied with regions with coating pattern exothermic to form a substrate that has differently colored regions.

Other substrates may also be employed to provide the exothermic properties of the substrate. For example, a first substrate can be used in conjunction with a second substrate. The substrates can work together to provide heat to a surface, or each can provide heat to different surfaces. Additionally, the substrates can be used that are not applied with the exothermic coating of the present invention, but instead are applied with a coating that simply facilitates the reactivity of the exothermic coating. For example, a substrate may be used near or adjacent to the substrate of the present invention that includes a coating of moisture retaining particles. As previously described, moisture retaining particles can retain moisture release to activate the exothermic reaction.

As previously indicated, moisture and oxygen are supplied to the exothermic coating to activate the exothermic reaction. To provide the desired heat profile, the rate at which moisture is allowed to contact the exothermic coating can be selectively controlled in accordance with the present invention. Mainly, if a lot of moisture is supplied within a given period of time, the exothermic reaction can produce an excessive amount of heat that overheats or burns the user. On the other hand, if very little moisture is supplied within a given period of time, the exothermic reaction may not be sufficiently activated. The desired application rate can of course be achieved by manually applying the desired amount of moisture, for example, by hand or with the aid of external equipment, such as a syringe. Alternatively, the thermal insert itself may contain a mechanism to control the rate of moisture release.

A technique for using the thermal insert as a mechanism to control the rate of application of moisture involves the use of a moisture retaining layer. The moisture retaining layer can be used in the thermal insert to retain moisture and in a controlled manner release it to the exothermic coating over an extended period of time. The moisture retaining layer may include an absorbent fabric formed in accordance with any conventional technique or method, such as a dry forming technique, and an air laying technique, a carding technique, a spinning or meltblowing technique, a wet forming technique, a foaming technique, etc. In a laying process with air, for example, a bundle of small fibers having typical lengths in the range of about 3 to about 19 millimeters is separated and introduced into an air supply and then deposited on a forming screen, usually with the assistance of a Vacuum supply. The randomly deposited fibers are then joined to one another using, for example, hot air or an adhesive.

The moisture retaining layer typically contains cellulosic fibers, such as synthetic and / or natural fluff pulp fibers. Fiber pulp fibers can be kraft pulp, sulfite pulp, thermomechanical pulp, etc. Additionally, the fluff pulp fibers may include pulp of higher average fiber length, pulp of lower average fiber length, or mixtures thereof. An example of appropriate upper average length of fluff pulp fibers include soft wood kraft pulp fibers. Softwood kraft pulp fibers are derived from coniferous trees and include pulp fibers such as, but not limited to, the softwood species of the south, west, and north, which include redwood, red cedar, the fir, the Oregon pine, the real pines, the pine (for example, the southern pines), the red spruce (for example, the black spruce), the combinations thereof, and so on. Northern softwood kraft pulp fibers can be used in the present invention. An example of commercially available south softwood kraft pulp fibers suitable for use in the present invention includes those available from Weyerhauser Company with offices in Federal Way, Washington under the trademark designation of "NB-416". Another type of lint pulp that can be used in the present invention is identified with the trademark designation CR1654, available from U.S. Alliance of Childersburg, Alabama, and is a highly absorbent, bleached sulphate wood pulp that mainly contains softwood fibers. Yet another suitable fluff pulp for use in the present invention is a bleached, sulfate wood pulp containing mainly softwood fibers that is available from Bowater Corp. with offices in Greenville, South Carolina under the brand name pulp. CoosAbsorb S. Fibers of low average length can also be used in the present invention. An example of pulp fibers of low average length are the hardwood kraft pulp fibers. Hardwood kraft pulp fibers are derived from deciduous trees and include pulp fibers such as, but not limited to, eucalyptus, maple, birch, aspen, etc. Eucalyptus and kraft pulp fibers may be particularly desired to increase softness, improve brilliance, increase opacity, and change the pore structure of the sheet to improve its drainage ability.

If desired, the moisture retaining layer may also contain synthetic fibers, such as monocomponent and multi-component fibers (eg, bi-components). Multicomponent fibers, for example, are fibers formed from at least two thermoplastic polymers that are extruded from separate extruders, but linked together to form a fiber. In a multi-component sheath / core fiber, a first polymer component is surrounded by a second polymer component. The polymers of the multi-component fibers are arranged in distinct zones substantially constantly positioned across the cross section of the fiber and continuously extended along the length of the fibers. Various combinations of polymer voices for the multi-component fiber may be useful in the present invention, and but the first polymer component typically melts at a temperature lower than the melting temperature of the second polymer component. Casting the first polymer component allows the fibers to form a sticky skeletal structure, which upon cooling, captures and bonds many of the pulp fibers. Typically, polymers of multi-component fibers are made from many different thermoplastic materials, such as the polyolefin / polyester bicomponent fibers (sheath / core) in which the polyolefins (e.g., polyethylene sheath) were melted at a lower temperature than the core (e.g., polyester). Exemplary thermoplastic polymers include polyolefins (e.g., polyethylene, polypropylene, polybutylene, and copolymers thereof), polytetrafluoroethylene, polyesters (e.g., polyethylene terephthalate), polyvinyl acetate, polyvinyl chloride acetate, polyvinyl butyral, acrylic resins (for example polyacrylate, polymethacrylate, and polymethylmethacrylate), polyamides (for example, nylon), polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyurethanes, cellulose resins (for example, cellulose nitrate, cellulose acetate, cellulose acetate butyrate, and ethyl cellulose), and copolymers of any of the above materials, such as ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, block copolymers of styrene-butadiene, and so on.

The moisture retaining layer also includes a super absorbent material, such as natural, synthetic and modified natural materials. Super absorbent materials are materials that swell with water or are capable of absorbing at least about 20 times their weight and, in some cases, at least about 30 times their weight in an aqueous solution containing 0.9% by weight of water. sodium chloride. Examples of synthetic super absorbent material polymers include alkali metal and ammonium salts of polyacrylic acid and polymethacrylic acid, poly (acrylamides), polyvinyl ethers, maleic anhydride copolymers and with vinyl and alpha ethers. olefins, polyvinyl pyrrolidone, poly (vinylmorpholinone), polyvinyl alcohol, and mixtures and copolymers thereof. Additional absorbent materials include natural and modified natural polymers, such as grafted starch of hydrolyzed acrylonitrile, grafted acrylic starch, methyl cellulose, chitosan, carboxymethyl cellulose, hydroxypropyl cellulose, and natural gums, such as alginates, xanthan gum, locust bean gum and so on. Mixtures of natural and fully or partially synthetic super absorbent polymers may also be useful in the present invention. Other suitable absorbent gelling materials are described in US Pat. Nos. 3,901,236 issued to Assarsson et al .; 4,076,663 granted to Masuda and others; and the 4,286,082 granted to Tsubakimoto and others, which are incorporated here in their entirety by reference to them for all purposes.

When used, the super absorbent material can constitute about 1% by weight to about 40% by weight, in some embodiments, from about 5% by weight to about 30% by weight, and in some embodiments, from around from 10% by weight to about 25% by weight of the moisture retaining layer (on a dry basis). In the same way, multi-component fibers can constitute from about 1% by weight to about 30% by weight, in some embodiments, from about 2% by weight to about 20% by weight, and in some embodiments , from about 5% by weight to about 15% by weight of the moisture retaining layer (on a dry basis). Cellulosic fibers can also constitute up to 100% by weight, in some incorporations from about 50% by weight to about 95% by weight, and in some embodiments, from about 65% by weight to about 85% by weight. the layer that retains moisture (on a dry basis).

In accordance with the present invention, it has been found that the nature of the moisture retaining layer can be selected to provide a controlled rate of moisture evaporation of the moisture retaining layer. By controlling the rate of evaporation, the amount of moisture can be released to the exothermic coating within a given period of time. For example, it is usually desired that the average moisture "evaporation rate" of the moisture retaining layer is from about 0.05% to about 0.5%, in some embodiments from about 0.10% to about 0.25%., and in some additions, from around 0.15% up to around 0.20% per minute. The "evaporation rate" is determined by measuring the weight of the layer that retains moisture at a certain time, subtracting this measured weight from the initial wet weight of the layer, dividing this value by the initial wet weight, and then multiplying by 100. Evaporation rates are calculated for several different times and then averaged. The evaporation rate is determined in the present invention at a relative humidity of 51% and a temperature of about 22 ° C. It should be understand that this relative humidity and temperature conditions are "initial" conditions in which they can vary during the test due to the increased presence of water vapor in the atmosphere.

In some embodiments, the desired rate of evaporation of moisture is achieved by controlling the nature of the aqueous solution applied to the moisture retaining layer. Primarily, the current inventor has discovered that the application of only steam (vapor pressure of 23.7 mm Hg at 25 ° C) to the moisture retaining layer can sometimes result in a very large vapor action rate. Therefore, a soluble can be added to the aqueous solution to reduce its vapor pressure, for example, the tendency of water molecules to evaporate. At 25 ° C, for example, the soluble can be added so that the added aqueous solution retains moisture at an evaporation rate of less than 23.7 mm Hg, in some incorporations less than about 23.2 mm Hg, and in some Incorporations, from around 20.0 mm Hg to around 23.0 mm Hg. A particularly suitable class of solubles include the organic and / or inorganic metal salts. The metal salts may contain monovalent (eg, Na +), divalent (eg Ca2 +), and / or polyvalent cations. Examples of preferred metal cations include cations of sodium, potassium, calcium, aluminum, iron, magnesium, zirconium, zinc, and so on. Examples of preferred guns include halides, chlorohydrates, sulfates, citrates, nitrates, acetates, and so on. Particular examples of suitable metal salts include sodium chloride, sodium bromide, potassium chloride, potassium bromide, calcium chloride, etc. The actual concentration of the soluble of the aqueous solution can vary depending on the nature of the soluble, the particular configuration of the thermal insert, and the desired heat profile. For example, the soluble may be present in the aqueous solution in an amount from about 0.1% to about 25% by weight, in some embodiments from about 1% by weight to about 20% by weight, and in some embodiments , from about 5% by weight to about 15% by weight of the solution.

In addition to controlling the aspects of the aqueous solution, the moisture retaining layer itself can be selectively made to measure to achieve the desired evaporation rate. For example, the current inventor has discovered that moisture retaining layers having a relatively lower density and basis weight tend to release much of an amount of moisture compared to those having a higher basis weight and density. Without intending to be limited by theory, it is believed that such superior weight and higher density fabrics may have a lower porosity, making it more difficult for moisture to escape from the layer over a period of time.

Extended time. Therefore, in one embodiment of the present invention, the moisture retaining layer (eg, air-laid fabric) can have a density from retainer from 0.01 to about 0.50, in some embodiments from about 0.05 to about 0.25, and in some additions, from around 0.05 to around 0.15 grams per cubic centimeters (g / cm3). The density is based on the dry mass with oven of the sample of the thickness measurement and made at a load of 0.34 kilopascals (kPa) with a circular plate of 7.62 centimeters in diameter of 50% relative humidity and 23 ° C. Additionally, the base weight of the moisture retaining layer can be from about 50 to about 500 grams per square meter ("gsm"), in some incorporations from about 100 to about 300 grams per square meter, and in some incorporations, from around 150 around 300 grams per square meter.

Other techniques can also be employed to bend the desired rate of evaporation of moisture from the moisture containment layer. For example, super absorbent materials are capable of swelling in the presence of an aqueous solution. The swelling increases the absorption capacity of the moisture-containing layer, but similarly reduces the rate of evaporation of moisture by exhibiting the material a greater tendency to "hold onto" the water molecules. Therefore, the evaporation rate can be increased by reducing the degree of swelling. One technique for reducing the degree of swelling of a super absorbent material involves reducing the temperature of the aqueous solution below room temperature, such as less than about 25 ° C, and in some additions, from about 5 ° C to around 20 ° C. The degree of swelling of the super absorbent material can also be reduced by incorporating one or more ionic compounds into the aqueous solution to increase its ionic strength. The ionic compounds can be the same as the solutions described above. The "ionic strength" of a solution can be determined according to the following equation. i = 0.5 '? Zr? 'l Where, Zi the valence factor; Y my is concentration. For example, the ionic strength of a solution containing 1 molar calcium chloride and 2 molar calcium chloride is "3" and was determined as follows: 1 = 0.57 / 2 »* 1) + (11 * 2) J = 3 Without trying to be limited by a theory it is believed that super absorbent materials have an atmosphere Counter-ion with surrounds the ionic column of polymer chains that folds when their ionic strength is increased. Specifically, the counter-ion atmosphere is made up of charge ions opposite the charges along the column of a super absorbent polymer and are present in the ionic compound (eg, sodium or potassium cations surrounding the carboxylate anions distributed along the column of an anionic polyacrylate polymer). By increasing the concentration of ions that make contact with the super absorbent polymer, the gradient of ion concentration in the liquid phase from the outside to the interior of the polymer begins to decrease and the thickness of the counter-ion atmosphere ("Debye thickness") it can be reduced from about 20 nanometers (in pure water) to about 1 nanometer or less. When the counter-ion atmosphere is highly extended, the counterions are more osmotically active and therefore promote a higher degree of liquid absorbency. On the contrary, when the ion concentration the liquid absorbed increases, the counter-ion atmosphere collapses and the absorption capacity is decreased. As a result of the reduction in the absorption capacity, the super absorbent material exhibits less of a tendency to retain the water molecules, thus allowing its release to the exothermic composition.

If desired, a breathable layer can also be used which allows the flow of water vapor and air to activate the exothermic reaction, but it prevents an excessive amount of the liquids from making contact with the substrate, which can either suppress the reaction or result in an excessive amount of heat that overheats or burns the user. The breathable layer may contain a film capable of breathing. A film with adequate breathing capacity is a microporous film. The micropores form what is often referred to as tortuous trajectories throughout the film. The liquid in contact with one side of the film does not have a direct passage through the film. Instead, a network of microporous channels in the film prevents liquids from passing, but allows gases and water vapor to pass through. Microporous films can be formed from a polymer and a filler (for example, calcium carbonate) . The fillers are particles or other forms of materials that can be added to the film polymer extrusion mixture and that will not chemically interfere with the extruded film, but can be uniformly dispersed throughout the film. Generally, on a dry weight basis, based on the total weight of the film, the film includes from about 30% to about 90% by weight of a polymer. In some embodiments, the film includes from about 30% to about 90% by weight of a filler. Examples of such films are described in United States of America patents number 5,843,057 issued to McCormack; 5,855,999 granted to McComarck; 5,932,497 issued to Morman et al .; 5,997,981 granted to McComarck and others; 6,002,064 granted to Kobylivker and others; 6,015,764 issued to McComarck and others; 6,037,281 issued to Mathis and others; 6,111,163 granted to McComarck and others and 6,461,457 granted to Taylor and others which are hereby incorporated in their entirety by reference thereto for all purposes.

The films are generally made breathable by stretching the filled films to create the microporous conduits by breaking the polymer out of the filling (eg, calcium carbonate) during stretching. For example, the breathable material contains a stretched-thin film that includes at least two basic components, for example a polyolefin polymer and filler. These components are mixed together, heated and then extruded into a film layer using any one of a variety of film production processes known to those of ordinary skill in the art of film processing. Such film manufacturing processes include, for example, embedded embedding, flat and chilled setting and blown film processes.

Another type of film capable of breathing is a monolithic film which is a continuous non-porous film, which due to its molecular structure is capable of forming a vapor-permeable and liquid-impermeable sweep.

Among the various polymeric films that fall within this type include films made of a sufficient amount of polyvinyl alcohol, polyvinyl acetate, ethylene vinyl alcohol, polyurethane, ethylene methyl acrylate, and methyl ethylene acrylic acid to make them with capacity to breathe. Without attempting to be tied to a particular operating mechanism, it is believed that films made of such a polymer solubilize water molecules and allow the transport of these molecules from one surface of the film to the other. Therefore, these films can be sufficiently continuous, for example non-porous, to make them essentially impermeable to liquid, but still allow vapor permeability.

Breathable films, as described above, may constitute the fully breathable material, or may be part of a multi-layer film. The multi-layer films may be prepared by extrusion of blown or set film from the layers, by extrusion coating or by any conventional layering process. In addition, other breathable materials that may be suitable for use in the present invention are described in U.S. Patent Nos. 4,341,216 issued to Obenour; 4,758,239 granted to Yeo and others; 5,628,737 granted to Dobrin and others; ,836,932 awarded to Buell; 6,114,024 awarded Forte; 6,153,209 granted to Vega and others; 6,198,018 granted to Curro; 6,203,810 granted to Alemany and others; 6,245,401 granted to Ying and others, which are incorporated herein in their entirety by reference to them for all purposes.

If desired, the breathable film can also be attached to a non-woven fabric, a knitted fabric and / or a woven fabric using well-known techniques. For example, suitable techniques for joining a film to a non-woven fabric are described in U.S. Patent Nos. 5,843,057 issued to McComarck; 5,855,999 awarded to McCormack; 6,002,064 granted to Kobylivker and others; 6,037,281 issued to Mathis and others; and WO 99/12734, which are incorporated herein in their entirety by reference thereto for all purposes. For example, a non-woven laminate / breathable film material can be formed from a non-woven fabric and a breathable film layer. The layers may be arranged so that the breathable film layer is attached to the non-woven layer. In a particular embodiment, the breathable material is formed of a non-woven fabric (e.g., a polypropylene spunbonded fabric) laminated to the breathable film.

Although several configurations of a thermal insert have been described above, it should be understood that other configurations are also included within the scope of the invention. scope of the present invention. For example, other layers can be employed to improve the exothermic properties of the thermal insert. For example, a substrate may be used near or to one side of the substrate of the present invention that includes a particle coating that retains moisture. As described above, particles that retain moisture can retain and release moisture to activate the exothermic reaction. In addition, of a particular benefit, one or more of the aforementioned layers can achieve multiple functions of the thermal insert. For example, in some embodiments, the ability to breathe, the moisture containment layer, etc., may be applied with an exothermic coating and therefore also serve as a substrate. Although not expressly stated here, it should be understood that numerous other possible combinations and configurations may be well within the ordinary skill of those skilled in the art.

The breathable and / or moisture retaining layers described above can generally be arranged at any desired position relative to the exothermic coating. In this aspect, various configurations of the thermal insert of the present invention will now be described in greater detail. It should be understood, however, that the description given below is merely exemplary, and that other thermal insert configurations are also completed by the present inventor.

Referring to Figure 1, for example, an embodiment of a thermal insert 10 that can be formed in accordance with the present invention is shown. As shown, the thermal insert 10 defines two outer surfaces 17 and 19, and is in the form of an essentially planar, conformable and bendable material. The general size and shape of the thermal insert 10 are not critical. For example, the thermal insert 10 may have a shape that is generally triangular, square, rectangular, pentagonal, hexagonal, circular, elliptical, etc. As shown, the thermal insert 10 includes a substrate 12 that contains one or more exothermic coatings. In this embodiment, the breathable layers 14a and 14b are included within the thermal insert 10 which are impervious to liquids, but permeable to the bases. It should be understood that even when shown here as having two breathable layers, any number of breathable layers (if any) can be employed in the present invention. The thermal insert 10 also includes a moisture containing layer 16 that is configured to absorb and retain moisture for an extended period of time. The breathable layers 14a and 14b and the moisture containing layer 16 can be placed in various ways in relation to the substrate 12. In Figure 1, for example, the breathable layers 14a and 14b are placed directly to one side of the substrate 12. As a result, the breathable layers 14a and 14b they can prevent external liquids from contacting the substrate 12 and can also control the amount of air contacting the substrate 12 and over a given period of time. The moisture containment layer 16 may also be placed in several locations, but is generally positioned to help facilitate the moisture source for the substrate 12. It should be understood that, even though it was shown here as having a moisture containing layer, any number of layers (if any) may be employed in the present invention.

Although not specifically illustrated, the thermal insert 10 may also include several other layers. For example, the thermal insert 10 may employ a thermally conductive layer to help distribute the heat towards a user's direction (e.g., the direction -z) and / or along the x-y plane of the device 10, thereby improving the uniformity of the application of heat over a selected area. The thermally conductive layer may have a thermal conductivity coefficient of at least about 0.1 watts per meter-Kelvin (W / m-K), and in some embodiments from about 0.1 to about 10 watts per meter-kelvin. Although any thermally conductive material may be employed, it is often desired that the selected material be formable to improve the comfort and flexibility of the device 10. Suitable conformable materials include, for example, the fibrous materials (for example non-woven fabrics), films and others. Optionally, the thermally conductive layer may be permeable to vapor so that the air can make contact with the substrate 12 when it is desired to activate the exothermic reaction. A type of conformable and vapor permeable material that can be used in a thermally conductive layer is a nonwoven fabric material. For example, the thermally conductive layer may contain a non-woven laminate, such as a laminate bonded with spinning / meltblowing / spunbonded ("SMS"). Such SMS laminates can also provide an ability to breathe and protection through the transfer of liquid. The SMS laminate is formed by known methods, such as described in U.S. Patent No. 5,213,881 issued to Timmons et al., Which is hereby incorporated by reference in its entirety for all purposes. Another type of conformable and vapor permeable material that can be used in the thermally conductive layer is a breathable film. For example, the thermally conductive layer can sometimes use a nonwoven laminate / film capable of breathing.

A variety of techniques can be employed to provide the conductivity to the thermally conductive layer. For example, a metallic coating can be used to provide conductivity. Metals suitable for such purpose include, but are not limited to copper, silver, nickel, zinc, tin, palladium, lead, copper, aluminum, molybdenum, titanium, iron and others. Metal coatings can be formed on a material using any of a variety of known techniques, such as vacuum evaporation, electrolytic coating, etc. For example, the patents of the United States of America numbers 5,656,355 granted to Cohen; 5,599,585 granted to Cohen; 5,562,994 granted to Abba and others and 5,316,837 granted to Cohen, which are hereby incorporated in their entirety by reference thereto for all purposes, describe suitable techniques for depositing a metal coating on a material. In addition to a metal coating, still other techniques can be employed to provide conductivity. For example, an additive can be incorporated into the material (e.g. fibers, films, etc.) to improve conductivity. Examples of such additives include but are not limited to coal fillers, such as carbon fibers and powders; metal fillers such as copper powder, steel, aluminum powder and aluminum flakes; and ceramic fillers such as boron nitride, aluminum nitride and aluminum oxide. Commercially available examples of the conductive materials include, for example, the thermally conductive compounds available from LNP Engineering Plastics Inc. of Exton, Pennsylvania under the name Konduit® or Cool Polymers of Warwick, Rhode Island under the name CoolPoly®. Even when several examples of the materials Thermally conductive materials have been described above, it should be understood that any thermally conductive material can be generally used in the present invention.

In addition to the thermally conductive layer, still other optional layers can be employed to improve the effectiveness of the thermal insert 10. For example, an insulation layer can be used to inhibit the dissipation of heat to the outside environment so that the heat is instead focused on the patient or user. Because the insulation layer increases the overall heat production efficiency of the device 10, the desired temperature increase can be achieved with a lower amount of exothermic coating or other reagent (e.g., moisture or oxygen). The insulation layer can have a thermal conductivity coefficient of less than about 0.01 watts per meter-Kelvin (W / m-K), and in some additions from about 0.01 to about 0.05 W / m-K. Any known insulation material can be employed in the present invention. If desired, the selected insulation material may be fibrous in nature to improve the overall conformation of the thermal insert 10. The fibrous material may possess a high foaming to improve its insulating properties. Suitable high-flux materials may include porous woven materials, porous nonwoven materials, etc. Particularly suitable high-flux materials are multi-component polymeric fabrics (for example of bicomponent) nonwovens. For example, polymers of multiple components of such fabrics can be mechanically or chemically crimped to increase foaming. Examples of suitable high foaming materials are described in greater detail in U.S. Patent Nos. 5,382,400 issued to Pike et al .; 5,418,945 granted to Pike and others and 5,906,879 granted to Huntoon and others which are hereby incorporated in their entirety by reference for all purposes. Still other materials suitable for use in an insulation material are described in US Pat. No. 6,197,045 issued to Carson, which is hereby incorporated by reference in its entirety for all purposes.

The thermal insert 10 may also include layers that optionally form the outer surfaces 17 and 19, respectively, of the thermal insert 10. These layers may have a smooth feel, docility and a non-irritating surface to the wearer's skin. For example, the layers can be formed of materials that are permeable to liquid and vapor, impervious to liquid and permeable to vapor ("breathable") and others. For example, the layers can be formed from a meltblown fabric or bonded with polyolefin fiber yarn, as well as from a woven and bonded, short fiber and / or hydraulically entangled fabric of natural and / or synthetic fibers. In another embodiment, the layers can be formed from a non-woven laminate with ability to breathe (e.g., a film laminate capable of breathing / tissue bonded with spinning) as described above. The layers may further include a composition that is configured to transfer to the wearer's skin for an improvement of skin health. Suitable compositions are described in U.S. Patent No. 6,149,934 issued to Krzysik et al., Which is hereby incorporated by reference in its entirety for all purposes.

The various layers and / or components of the thermal insert 10 can be assembled together using any known fastening mechanism, such as adhesive, ultrasonic, thermal, etc. connections. Suitable adhesives may include, for example, hot melt adhesives, pressure sensitive adhesives and others. When used, adhesives can be applied as a uniform layer, a patterned layer, a spray pattern or any of separate lines, swirls or dots. In some embodiments, the exothermic coating can serve the dual purposes of generating heat and also act as the adhesive. For example, the binder of the exothermic coating can join together one or more layers of the thermal insert 10.

To further improve the amount of heat generated by the thermal insert, multiple substrates may sometimes be employed. Multiple substrates can be placed on one side of each other or spaced and separated by one or more layers. For example, referring to Figure 2, an incorporation of a thermal insert 100 is shown to contain a first substrate 112a and a second substrate 112b. Although not required, the thermal insert 100 also includes a breathable first layer 114a and a breathable second layer 114b. The thermal insert 100 also includes a moisture containing layer 116 to facilitate the supply of moisture to the substrates 112a and 112b. The moisture containment layer 116 is positioned between the substrate 112a and 112b. The moisture containment layer 116 is positioned between the substrate 112a / breathability 114b and the substrate 112b / breathing layer 114b. In this way, the amount of moisture supplied to each substrate is relatively uniform. It should be understood, however, that any placement, selection and / or number of layers can be employed in the present invention.

Moisture can be applied at any time before or during the use of the thermal insert, such as just before use or during manufacture. For example, water may be applied previously to the moisture containment layer as described above. The moisture is added in an amount effective to activate an exothermic electrochemical reaction between the electrochemically oxidizable element (e.g. metal powder) and the electrochemically reducible element (e.g., oxygen). Even when this amount it may vary depending on the reaction conditions and the amount of heat desired, moisture is typically added in an amount of from about 20% by weight to about 500% by weight, and in some embodiments, from about 50 % by weight to about 200% by weight of the weight of the amount of oxidizable metal present in the coating. Although not necessarily required, it may be desired to seal such thermal inserts treated with water within a material essentially impermeable to liquid (vapor permeable or vapor impermeable) or package (not shown) that inhibits the thermal coating from contacting with sufficient oxygen to prematurely activate the exothermic reaction. To generate heat, the thermal insert is simply removed from the package, exposed to air, and inserted into a cavity defined by the pad.

Through selective control over the supply of these reagents, a heating profile can be achieved in which a high temperature is quickly reached and maintained over an extended period of time. For example, a high temperature of from about 30 ° C to about 60 ° C, in some additions from about 35 ° C to about 55 ° C, and in some additions from about 37 ° C, to around 43 ° C, can be achieved in 20 minutes or less and in some additions, 10 minutes or less. This elevated temperature can be maintained essentially at least by about 1 hour, and in some additions at least around 2 hours, in some additions at least around 4 hours, and in some additions, at least around 10 hours (for example for a night use).

The therapeutic kit of the present invention can be used to apply uniform heat and pressure to a pressed or irritated area to reduce pain, discomfort or a cramp. For example, pressure and heat can be applied to the extensor muscles and tendons in the upper forearm to relieve pain and discomfort associated with epicondylitis or "tennis elbow". The application of heat and pressure through the extensor muscles and tendons prevents the firing of these muscles. In this way, the contraction and use of these irritated or stressed muscles is inhibited to reduce the pain and discomfort associated with the tennis elbow or other injury. Applying pressure to irritated or injured muscles can also improve the healing process by avoiding the use of these muscles and giving the muscles enough rest to allow healing to occur and avoid further injury.

The present invention can be better understood with reference to the following examples.

Example 1 The ability to form a thermal insert according to the present invention was demonstrated. Initially, a roll of 7 inches wide of a dual layer of 2.3 ounces per square yard of a woven and bonded fabric (one side contains 0.5 ounces per square yard of 100% bicomponent fibers (PE sheath / PP core) FiberVisions ESC 215 of 1.5 denier with a finish of 0.55% HR6 and the other side contains 1.8 ounces per square yard of a 40% blend of Invista T-295 polyester fiber of 15 deniers with 0.50% finished Ll and 60% a bicomponent fiber (PE sheath / PP core FiberVisions ESC 28 denier with a 0.55% HR6 finish) was coated on the bicomponent / polyester fiber side.The coating formulation was prepared as follows. metal of two gallons, 46.0 grams of METOLOSE SM-100 (Shin-Etsu Chemical Company, Limited) and 116.0 grams of sodium chloride were added (Mallinckrodt) to 1563.0 grams of distilled water that were stirred and heated to 70 ° C. The mixture was allowed to stir and allowed to cool when the following additional ingredients were added in frequency: 186.6 grams of ethylene vinyl acetate emulsion DUR-O-SET® Elite PE 25-220A (emulsions) Celanese), 442.2 grams of a calcium carbonate solution XP-5200-6 shows number 0.52435503 (Omaya), 80.0 grams of Nuchar SA-400 activated carbon (MeadWestvaco), and 1575.1 grams of an iron powder A-131 (NorthAmerican Hóganás). After about 30 minutes of stirring the formulation with all the ingredients, the temperature was reduced with an ice bath at about 15 ° C. A noticeable increase in viscosity occurred when the temperature was reduced. The calculated concentration of each component of the aqueous formulation is stated below in Table 1.

Table 1: Components of the aqueous formulation The aqueous formulation was applied to the bicomponent / polyester fiber side of the dual layer bonded and carded woven fabric in a pilot line process using a knife coater. A melt-blown spunbond-bonded yarn fabric of 0.75 ounces per square yard was used as a carrier sheet to support carded and bonded dual coated fabric and also to keep the coating formulation from bleeding and contacting with the components of the pilot coater (for example, rollers). The separation between the blade and the steel roller that carried the cloth was set to 1,100 microns. The line speed was 0.25 meters per minute. The pilo line coater contained a 4-foot dryer set at 145 degrees centigrade that was used to partially dry the coated cloth. The partially dried coated fabric was cut into 15 inch pieces and placed in a laboratory oven at 110 ° C for about 20 minutes to complete the drying step. The concentration of the components of the exothermic composition was calculated from the coated and dried cloth pieces (56.4 ± 0.8 grams), the untreated piece of cloth (4.0 grams), and the composition of the aqueous formulation. The results are set down in table 2.

Table 2: Components of the exothermic composition A five-layer structure (1.8"x 2.2") was then designed to activate the exothermic reaction. Specifically, the five-layer structure included one of the coated fabric pieces placed on one side of a moisture-containing layer, and another piece of coated fabric placed on the other side of the moisture-containing layer. The uncoated side of the fabric pieces faces the moisture containment layer. The containment layer of moisture was formed of 75% by weight of wood pulp fluff, 15% by super absorbent weight and 10% by weight of KoSa T255 bicomponent fiber. The moisture containment layer had a basis weight of 225 grams per square meter and a density of 0.12 grams per cubic centimeter. The wood pulp fluff was obtained from Weyerhaueser under the name "NB416". The super absorbent was obtained from Degusta AG under the name "SXM 9543". A "separation layer" was used to separate the moisture containing layer from the coated layer on each side. The separation layer was a fabric / film laminate with small perforated holes to allow steam and gas to pass while preventing the passage of the liquid. This was obtained from Tredegar Film Products with the label FM-425 lot number SHBT040060.

Prior to the formulation of the multi-layer structure, the moisture containment layer was wetted by spraying 1.8 grams of an aqueous salt solution (10% sodium chloride in distilled water) on both sides so that the weight of the the original layer was increased by a factor of 3.7. Then the separation layer was placed around it with the fabric side of the separation layer in contact with the wet moisture containment layer. A coated layer was then placed on each side of the uncoated side in contact with the film side of the separation layer. The total weight of the two coated layers was 5.0 grams (3.5 grams of iron). The five-layer structure was then placed inside a bag (2.2 inches by 5.5 inches) and the edges were sealed with heat. The bag was made of a laminated microporous film bonded with nylon yarn. The laminate was obtained from Mitsubishi Corporation and labeled TSF type EDFH 5035. The water vapor transmission rate of the laminate was measured at 455 grams per square meter per 24 hours using a cup method (STM 2437). The bag also contained a layer of woven fabric with yarn sealed to the side attached with nylon yarn. The short woven fabric was produced from 20% wood pulp fluff (50% northern softwood kraft fibers / 50% softwood kraft bleached Alabama pine), 58% polyester fiber 1.5 deniers ( type Invista 103) and 22% bonded with polypropylene yarn (Kimberly-Clark Corporation). The resulting thermal insert was stored in a metallized storage bag for 48 hours before activation of the reaction. The metallized storage bag was KAL-ML5, a two-layer structure consisting of a metallized polyester adhesively laminated to linear low density polyethylene obtained from Kapak Corporation.

Example 2 The ability to assemble a therapeutic kit according to an embodiment of the present invention was demonstrated. Initially, an arm band having the Aircast® pneumatic arm band designation was obtained from Aircast Inc. The arm band contained a "specialized air cell" insert attached to an extensible material. The "air cell" insert was removed and replaced with a thermal insert of example 1. The arm band containing the thermal insert was placed on a human arm so that the thermal insert was adjacent to the tendon above the elbow. A thermocouple was placed intermittently between the thermal insert and the skin. The thermocouple was wired to a data collection device to record the temperature as a function of time (at intervals of 5 seconds). After 90 minutes, the arm band was removed and the thermocouple was left in contact with the thermal insert for about 14 hours. The resulting thermal response data are shown in Figure 7. As indicated, the temperature between the skin and the thermal insert reached around 38 ° C. With the removal of the arm band, the temperature of the thermal insert only remained at 36-38 ° C for an additional 4 hours. The temperature of the other human arm was measured at 34.6 ° C. Therefore, the arm band was successful in heating the arm by from about 34 to 38 ° C. If necessary, the temperature provided by the thermal insert can be adjusted to provide more or less heat, such as by changing the composition of the exothermic coating.

Although the invention has been described in detail with respect to a specific embodiment thereof, it will be appreciated by those skilled in the art to achieve an understanding of the foregoing that alterations, variations and equivalents of these embodiments can be easily conceived. Therefore, the scope of the present invention should be evaluated as that of the appended claims and any equivalent thereof.

Claims (22)

R E I V I N D I C A C I O N S

1. A therapeutic kit comprising: a pad defining a cavity; Y a thermal insert that is capable of being removably placed within the cavity, the thermal insert comprises a substrate containing an exothermic coating, the exothermic coating comprises an oxidizable metal, wherein the exothermic coating is activated upon exposure to oxygen and moisture to generate heat.

2. The therapeutic package as claimed in clause 1, characterized in that the case contains an extensible material.

3. The therapeutic package as claimed in clause 2, characterized in that the extensible material contains a film, a non-woven fabric or combinations thereof.

4. The therapeutic package as claimed in clauses 2 or 3, characterized in that the extensible material contains an elastomeric polymer.

5. The therapeutic package as claimed in clauses 2, 3, 4 characterized in that the cavity is defined by a receptacle that is attached to the extensible material.

6. The therapeutic package as claimed in any one of the preceding clauses, characterized in that the pad comprises one or more curls.

7. The therapeutic package as claimed in any one of the preceding clauses, characterized in that the pad comprises one or more fasteners.

8. The therapeutic kit as claimed in any one of the preceding clauses, characterized in that the metal is iron, zinc, aluminum, magnesium or a combination thereof.

9. The therapeutic kit as claimed in any one of the preceding clauses, characterized in that the exothermic coating further comprises a carbon component, a binder, an electrolytic salt or a combination thereof.

10. The therapeutic kit as claimed in any one of the preceding clauses, characterized in that the exothermic coating is present at an aggregate level of solids of from about 20% to about 5,000% and preferably from about 100% to about of 1,200%.

11. The therapeutic kit as claimed in any one of the preceding clauses, characterized in that the substrate contains a non-woven fabric.

12. The therapeutic package as claimed in any one of the preceding clauses, characterized in that the exothermic coating is generally free of moisture before activation.

13. The therapeutic kit as claimed in any one of the preceding clauses, characterized in that the thermal insert is sealed inside an enclosure that inhibits the passage of oxygen to the exothermic coating before activation.

14. The therapeutic package as claimed in any one of the preceding clauses, characterized in that the thermal insert further comprises a moisture containing layer that is applied with a solution aqueous, the aqueous solution being able to supply moisture to the exothermic coating.

15. The therapeutic kit as claimed in clause 14, characterized in that the aqueous solution comprises one or more solutions.

16. The therapeutic package as claimed in any one of the preceding clauses, characterized in that the thermal insert further comprises a breathable layer that is capable of regulating the amount of moisture and oxygen that make contact with the exothermic coating.

17. A method for providing heat to a part of the body, the method comprises providing a thermal insert containing an exothermic coating that is activated upon exposure to moisture and oxygen to generate heat, wherein the thermal insert is sealed within the enclosure that inhibits the passage of oxygen to the exothermic coating; open the enclosure and place the thermal insert inside the cavity defined by a pad; YPlace the pad on one side of the body part or close to it.

18. The method as claimed in clause 17, characterized in that the exothermic coating contains an oxidizable metal.

19. The method as claimed in clauses 17 or 18, characterized in that the coating is free of moisture before activation.

20. The method as claimed in clauses 17, 18, or 19 characterized in that one or more surfaces of the thermal insert reach an elevated temperature of from about 35 ° C to about 55 ° C in 20 minutes or less.

21. The method as claimed in clause 20, characterized in that the elevated temperature is maintained at least about 1 hour and preferably at least about 2 hours.

22. The method as claimed in clauses 20 or 21, characterized in that the pad is placed on one side of the arm or close to it. SUMMARY A therapeutic case is provided to provide heat to an area of the body. The therapeutic kit can be used to treat a variety of injuries to muscles, ligaments, tendons, etc., including arm, leg, ankle, knee, shoulder, foot, neck, back, and arm injuries. elbow, wrist, hand, chest, finger and toe and others. Regardless of its intended use, the therapeutic kit generally employs a pad that receives a thermal insert. The thermal insert includes a substrate that contains an exothermic coating that is capable of generating heat in the presence of oxygen and moisture. A particular benefit of the thermal insert of the present invention is that it is disposable. Therefore, when the thermal insert exhausts its ability to produce heat, a new insert can simply be used. This allows the continued use of the extensible material, resulting in substantial cost savings for the consumer.