Exothermic expandable composition

Abstract

An expandable exothermic gel-forming composition, which is mainly used in the consumer and medical industries. More specifically, it relates to the use of an expandable particulate exothermic gel-forming composition having effective and long-lasting heat generation for heating surfaces and objects without electricity or combustible fuel.

Description

[0001] This application is a divisional application of International Application No. 201780084053.8, filed with the State Intellectual Property Office on December 13, 2017, and entitled "Exothermic Expandable Composition".

[0002] Cross - reference to related applications

[0003] This application claims the priority of U.S. Provisional Application No. 62 / 433,766, filed on December 13, 2016, the content of which is incorporated herein by reference in its entirety as if set forth verbatim. Technical field

[0004] The present disclosure generally relates to exothermic compositions, which are mainly used in the consumer and medical industries. Background art

[0005] In many applications, there is a need to generate heat without using electricity or burning fuel. In the cosmetics industry, heat is required to apply various cosmetics to the skin and scalp. In the medical field, the application of heat is important in physical therapy, plastic surgery, wound healing, arthritis treatment, etc. In consumer products, there is a need to keep food and other substances warm and initially heat them when other heating methods are inconvenient or unavailable.

[0006] The use of exothermic chemical reactions in these applications has been described. For example, since at least 1973, the military has used "flameless heating devices" to heat military rations in the field. These devices are in the form of "heat sheets" composed of magnesium anodes, carbon electrodes, and electrolyte salts. Recently, the military has developed a dismounted ration heating device (DRHD) that utilizes a chemical heating pad composed of magnesium - iron alloy particles trapped in a semi - solid polyethylene matrix (see, for example, U.S. Patent No. 4,522,190).

[0007] Other examples of metal alloy particles that generate heat in the cosmetics industry have been described, which are used as absorbent materials together with paper - based "fluff". However, such systems have relatively low energy potential, and thus exhibit short - duration exothermic reactions and non - uniform heating.

[0008] Therefore, there is a need for compositions that can be used to generate heat in a convenient form that is safe, uniform, controllable, and long - lasting. Accordingly, there is a need to address these and other problems in the art. Summary of the invention

[0009] The following simplified summary is provided to offer a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview and is not intended to identify key / essential elements or describe the scope of the claimed subject matter. Its purpose is to present some concepts in a simplified form as a prelude to the more detailed description that follows.

[0010] In one embodiment, there is provided an inflatable exothermic particulate gel-forming composition comprising first and second galvanic alloy particles (or at least two different galvanic alloy particles, optionally alloyed together). In other embodiments, more than two different galvanic alloy particles may be provided. A metal sub-shell composed of at least one transition metal; and a superabsorbent polymer; wherein the first and second galvanic alloy particles (or each of two or more different galvanic alloy particles), the metal sub-shell, and the superabsorbent polymer are mixed with each other; wherein when the gel-forming composition is exposed to water and an electrolyte, it swells upon hydration of the gel-forming composition and produces an exothermic reaction that generates heat for a predetermined duration. In some embodiments, the first and second galvanic alloy particles, the metal sub-shell, and the superabsorbent polymer are mixed with each other to achieve electrical contact. In some embodiments, a powder mixture is formed from the first and second galvanic alloy particles mixed with the superabsorbent polymer. The predetermined duration can range from a few minutes (e.g., 5 minutes) to several hours (e.g., 8 hours), but can be any desired or required duration. In the present disclosure, the term "predetermined" used in connection with the duration may be based on what is known or expected of the corresponding composition, but is not determined in every instance or something the user must know, unless explicitly defined as such.

[0011] The claimed composition provides gas inhibition, such as hydrogen inhibition, or inhibition of gases typically produced by the underlying exothermic reaction, such that these gases do not escape from the formed composition (referring to the reacted, reacting, formed, gel / foam, swelling, or swollen, exothermic, etc. composition) or their escape is inhibited to a significant degree as discussed herein. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gases produced by the exothermic reaction are inhibited and not released from the composition.

[0012] In some embodiments, activated carbon is used with the composition as an odor absorber. The activated carbon may be present in an amount of about 2% to 25% of the composition. The activated carbon may include a combination of graphite materials and other carbon powders of various particle sizes.

[0013] In one embodiment, the expandable exothermic composition can comprise two or more different metal particles, each having a different oxidation potential. A metal sub-shell can be included, which has at least one transition metal. A superabsorbent polymer can be included. The first galvanic alloy particle and the second galvanic alloy particle, the metal sub-shell, and the superabsorbent polymer can be mixed with each other (e.g., mixed into a uniform powder mixture), and when the gelling composition is exposed to water and an electrolyte, it expands as the gelling composition hydrates to produce an exothermic reaction that generates heat for a predetermined duration. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0014] In an embodiment that is generally included, there is provided an expandable exothermic composition comprising: a first galvanic alloy particle and a second galvanic alloy particle (or at least two different metal galvanic alloy particles, which are optionally alloyed together); a superabsorbent polymer; and potassium permanganate or potassium ferrate; wherein the first metal galvanic alloy particle and the second metal galvanic alloy particle (or each of two or more different metal galvanic alloy particles), potassium permanganate or potassium ferrate, and the superabsorbent polymer are mixed with each other; wherein when the composition is exposed only to water and an electrolyte, it expands as the composition hydrates to produce an exothermic reaction and generates heat for a predetermined duration. In certain embodiments, the first galvanic alloy particle and the second galvanic alloy particle comprise MgFe and MnO2. Generally, during the exothermic reaction, about 37% to about 93%, or more than 93% of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0015] In another embodiment, there is provided an expandable exothermic composition comprising: manganese oxide mixed with a superabsorbent polymer; and wherein when the composition is exposed only to an aqueous solution, it expands as the gelling composition hydrates to produce an exothermic reaction and generates heat for a predetermined duration. In some embodiments, the manganese oxide is manganese dioxide. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0016] In some embodiments, the composition expands to form a rigid foam. In some embodiments, the composition puffs up as the composition hydrates. In some embodiments, the aqueous solution is hydrogen peroxide and the buffering agent is a mixture of compressed sponge and / or clay particles. In embodiments regarding this, the composition of this embodiment can expand to form a rigid foam. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0017] A kit is also provided, such as a kit that includes: a container; an exothermic particulate gelling composition according to any one of the preceding claims; an aqueous activator solution, wherein a superabsorbent polymer can function to absorb the aqueous activator solution to cause the gelling composition to expand as the gelling composition hydrates; and an operating guide that illustrates that the composition is activated to generate heat for a predetermined duration when the composition contacts the aqueous activator solution in the absence of air.

[0018] In another embodiment, an expandable exothermic particulate gelling composition is provided, which includes: first and second galvanic alloy particles including magnesium and iron; a metal secondary shell composed of at least one transition metal, the transition metal including manganese dioxide; and a superabsorbent polymer including sodium polyacrylamide; wherein the first and second galvanic alloy particles, the metal secondary shell, and the superabsorbent polymer are mixed with each other; wherein, when the gelling composition is exposed to water and an electrolyte, it expands as the gelling composition hydrates and produces an exothermic reaction that generates heat for a predetermined duration. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0019] In another embodiment, an expandable exothermic composition is provided that has first and second galvanic alloy particles including magnesium and manganese oxide (i.e., thus the galvanic alloy particles do not include iron). A superabsorbent polymer and carbon particles may be included. The first and second galvanic alloy particles, the superabsorbent polymer, and the carbon particles can be mixed with each other. The composition expands as the composition hydrates with water, and no electrolyte such as salt needs to be included in the water. Hydrating the composition can produce an exothermic reaction that generates heat for a predetermined duration. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0020] In another embodiment, there is provided an expandable exothermic (granular) gel-forming composition comprising: first and second galvanic alloy particles comprising magnesium and iron; a superabsorbent polymer comprising sodium polyacrylamide; and potassium permanganate or potassium ferrate; wherein the first and second metallic galvanic alloy particles, the potassium permanganate or potassium ferrate, and the superabsorbent polymer are mixed with each other; wherein when the gel-forming composition is exposed only to water and electrolyte, it swells upon hydration of the gel-forming composition and generates heat for a predetermined duration. In certain related embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0021] In another embodiment, there is provided an expandable exothermic composition that is puffable and / or moundable, comprising: manganese oxide mixed with a superabsorbent polymer comprising sodium polyacrylamide. This embodiment may use the superabsorbent polymers disclosed herein that are not sodium polyacrylamide. When the composition is exposed only to an aqueous solution, it swells upon hydration of the composition and generates heat for a predetermined duration. In certain embodiments, during the exothermic reaction, most (or the percentage described herein) of the gas generated by the exothermic reaction is inhibited and not released from the composition.

[0022] In another embodiment, there is provided a kit comprising: a container; an exothermic granular gel-forming composition according to any one of the preceding claims; an aqueous activator solution comprising water or a salt solution, wherein the superabsorbent polymer can function to absorb the aqueous activator solution to cause the gel-forming composition to swell upon hydration of the gel-forming composition; and an operating guide that illustrates that the composition is activated to generate heat for a predetermined duration when contacted with the aqueous activator solution in the absence of air.

[0023] In common embodiments contemplated herein, the composition is adapted to provide minimal or near-zero gas that is generated or released from the composition (i.e., the reacted, reacting, formed, gelled / foamed, expanding or expanded, exothermic, etc. composition) during or as a result of an exothermic reaction. Typically, during or as a result of an exothermic reaction, from about 37% to about 93% of the gas generated by the exothermic reaction is inhibited and not released from the composition. Typically, during or as a result of an exothermic reaction, from about 93% to about 100% of the gas generated by the exothermic reaction is inhibited and not released from the composition. In commonly included embodiments, during or as a result of an exothermic reaction, more than 40% or more than about 40%, more than 45% or more than about 45%, more than 50% or more than about 50%, more than 55% or more than about 55%, more than 60% or more than about 60%, more than 65% or more than about 65%, more than 70% or more than about 70%, more than 75% or more than about 75%, more than 80% or more than about 80%, more than 85% or more than about 85%, more than 90% or more than about 90%, or more than 95% or more than about 95% of the gas generated by the exothermic reaction is inhibited and not released from the composition (again, the reacted, reacting, formed, gelled / foamed, expanding or expanded, exothermic, etc. composition).

[0024] Other aspects of the disclosed technology can be seen in this specification. However, for the foregoing and related purposes, the aspects disclosed in the specification merely illustrate some of the various ways in which the principles of the claimed subject matter can be employed, and the claimed subject matter is intended to include all such aspects and their equivalents. Other advantages and novel features will become apparent from the following detailed description. Detailed Description

[0025] The present technology pertains to the field of expandable exothermic gelling compositions, which are mainly used in the consumer and medical industries. More specifically, the solution disclosed herein relates to the use of expandable particulate exothermic gelling compositions that are capable of generating heat persistently and effectively for heating surfaces and objects without air, without the need for electricity or combustible fuel. The disclosed exothermic gelling compositions are typically formulated by several methods.

[0026] For clarity and / or for ease of reference, terms with their ordinary and customary meanings may be defined herein, and these definitions included herein shall not be construed as representing a substantial difference from what is ordinarily understood in the art. All patents, applications, published applications, and other publications mentioned herein are incorporated by reference in their entirety. If the definitions set forth in this section conflict with or are inconsistent with the definitions described in the patents, applications, published applications, and other publications incorporated by reference herein, the definitions set forth in this section shall prevail over the definitions incorporated by reference herein.

[0027] As used herein, "a" or "an" means "at least one (kind)" or "one (kind) or more (kinds)".

[0028] As used herein, the terms "user", "subject", "end user", etc. are not limited to a particular individual or person. For example, the term "user" may refer to a person who uses the systems and methods described herein, and may generally be a technician. However, the term is not limited to end users or technicians, and thus includes a wide variety of persons who may use the disclosed systems and methods.

[0029] Turning to the following detailed description, the disclosed technical solutions can now be better understood. It should be clearly understood that the described embodiments are presented by way of example and not by way of limitation of the embodiments as finally defined in the claims.

[0030] It should be understood that "galvanic alloy" may refer to a metal made by combining two or more metal elements (including combining two or more different metal salts). The combination is typically by known alloying methods, including, for example, alloying methods that employ a ball mill, etc.

[0031] It should be understood that the term "mixing" may mean mixing two or more substances together to form a mixture, such as (uniformly or non-uniformly) mixed powders, a homogeneous mixture, or a homogeneous powder. Mixers that can be used to "mix" two or more substances together may include commercially available stirrers and mixers, such as drum stirrers, Braun stirrers, belt mixers, blade mixers, V-shaped mixers, batch stirrers, etc.

[0032] It should be understood that the term "activator solution," may refer to water, water and electrolytes, or other aqueous solutions that, when in contact with any exothermic composition of the present disclosure, initiate, increase, or renew an exothermic reaction.

[0033] As used herein, the term "gel" is intended to mean materials that are traditionally known as gels in the art, as well as foams and combinations thereof. Generally, when formed, the foam is a foam having a certain degree of structural rigidity or shape attachment, such as a rigid foam. Such a rigid foam is capable of withstanding deformation by resisting a certain degree of external force, or is a self-supporting foam composition. Thus, herein, a composition that forms a gel is intended to mean a composition that forms a gel, and also, unless expressly stated otherwise, a composition that forms a foam. And for example, herein, an exothermic gel is intended to mean an exothermic gel composition, and also, unless expressly stated otherwise, an exothermic foam composition. And for example, herein, a bulging gel or gel matrix is intended to mean a bulging foam or foam matrix, unless expressly stated otherwise.

[0034] As used herein, an "exothermic composition" can refer to an "exothermic composition" before, during, or after the exothermic reaction of the composition begins.

[0035] The use of self-heating compositions is well known. Magnesium-iron alloys activated by salts and water have been used in the military and recreational markets for decades. However, all of these reactions are uncontrollable, violent, and short-lived. These reactions use redox reactions to effectively oxidize metal elements by splitting water molecules into oxygen to generate heat while releasing hydrogen. Due to the explosiveness of hydrogen under normal atmospheric conditions, this evolution of hydrogen can be a major limiting factor for the places where these compositions can be used.

[0036] Existing self-heating methods incorporate a galvanic alloy (such as an Mg-Fe alloy) in combination with a superabsorbent polymer (SAP). Subsequently, such methods have achieved self-expanding gels that are formed by the swelling action when the SAP comes into contact with an aqueous solution (such as water or a saline solution). This subsequently allows the corresponding exothermic gel to expand to the contour around an object and fill voids. More importantly, the swelling agent of the SAP electronically interferes with the oxidation process of Mg-Fe, and with an understanding of the hydrogen bonding forces that play a role in the reaction, a controlled reaction can be designed that has a calculated heat output over a known time period. By leveraging electron sharing and hydrogen bonding forces in the tug-of-war between the oxidation tendency of the galvanic alloy in the presence of water and electrolyte, the heat-time buffering effect of the SAP acts within its own structure. More specifically, the electronic attraction of the salt solution and the SAP matrix, i.e., hydrogen bonding and valence sharing. However, although the controlled, calculated, time-released exothermic reaction powered by water is suitable for many situations, it still has the drawback of forming hydrogen as a by-product of the reaction.

[0037] Galvanic alloy particles

[0038] As discussed throughout this disclosure, those embodiments of the disclosed technology that include galvanic alloy (GA) particles can be composed of a mixture of two or more metal reagents, each having a different oxidation potential, such that once the two components of the composition are brought into electrical contact with each other through an activator solution, one acts as a cathode and the other as an anode in an electrochemical reaction.

[0039] Exemplary metal reagents can include mixtures of copper, nickel, palladium, silver, gold, platinum, carbon, cobalt, aluminum, lithium, iron, iron (II) oxide, iron (III) oxide, magnesium, manganese, Mg2Ni, MgNi2, Mg2Ca, MgCa2, MgCO3, MnO2, and combinations thereof. For example, platinum can be dispersed on carbon, and the dispersion used as a cathode material. See, for example, U.S. Patents 3,469,085, 4,264,362, 4,487,817, and 5,506,069.

[0040] An exemplary anode material is magnesium, which reacts with water to form magnesium hydroxide (Mg(OH)2) and hydrogen gas to generate a large amount of heat. Other metal reagents with high standard oxidation potentials (such as lithium) can also be used as anode materials, but are less preferred from a cost and safety perspective. The cathode material will have a lower standard oxidation potential than the anode material. The cathode is not consumed in the electrochemical interaction, but rather serves as a site for neutralizing the electrons released by the corroding anode and the positively charged ions in the electrolyte. Exemplary cathode materials include iron, copper, and cobalt.

[0041] In certain exemplary embodiments, the galvanic alloy comprises two different alloys alloyed together. Most commonly, such an alloy comprises a combination of two different galvanic alloys described and / or contemplated herein. For example, in one embodiment, the galvanic alloy comprises MgFe alloyed with MnO2.

[0042] Any common method can be used to produce galvanic alloys, such as conventional dissolution or mechanical alloying. The process of mechanical alloying involves inducing solid-state reactions between the components of the initial powder mixture by repeated mechanical deformation caused by ball-powder-ball collisions, for example, using a high-energy ball mill. Such mechanical deformation can include, for example, repeated flattening, fracturing, and welding of metallic components (e.g., active or inert metal particles). The resultant energy generated by the impact of the colliding steel balls with the particles sandwiched between them creates atomically clean particle surfaces. These atomically clean particle surfaces allow them to be cold welded together.

[0043] The particle size of the metal component before grinding can vary from a few microns to hundreds of microns. In one embodiment, it may be desirable to have an average particle size of less than 200 microns, such as 100 microns to 150 microns, to promote effective alloying.

[0044] Exposure to oxygen or certain other reactive compounds produces a surface layer that reduces or completely eliminates the cold welding effect. Thus, an inert atmosphere can be maintained in the grinder to prevent re-oxidation of the cleaned surface, thereby avoiding the formation of an oxide overlay on the particle surface that reduces the galvanic reaction. The "inert gas" used herein is a non-reactive gas such as nitrogen, helium, neon, argon, krypton, xenon, radon, and also includes non-oxidizing gases, carbon dioxide. The inert gas should be substantially free of water (less than 10 ppm, e.g., less than 5 ppm or less than 1 ppm).

[0045] Typically, when allowing the grinding process to proceed for an extended period of time, the particle structure becomes finer and the cathode particle size decreases. However, after a certain point during the grinding process, any additional grinding will result in a decrease in the corrosion rate because the cathode material becomes too finely dispersed throughout the anode material. When this occurs, the ratio of the cathode / anode particle surface area available for contact with the electrolyte decreases, and thus the corrosion rate decreases. The mechanically alloyed powder obtained by the grinding process is small particles that consist of an active metal matrix in which smaller inert metal particles are dispersed. Thus, the grinding time should be optimized to obtain the best results in terms of conductivity. In one embodiment, the galvanic alloy particles consist of magnesium and nickel, magnesium and iron, magnesium and copper, and magnesium and cobalt (U.S. Patent No. 4,264,362). In magnesium-containing alloys, magnesium is typically present in a greater abundance, e.g., greater than 75%, 80%, 90%, or 95% by weight percentage.

[0046] Superabsorbent polymer

[0047] In those embodiments of the disclosed technology that include a superabsorbent polymer (SAP), it is to be understood that the SAP can be a "slush powder", a "water-insoluble absorbent hydro gel-forming polymer", a "hydro gel-forming" polymer, or a "hydrocolloid". The use of SAP is important because when combined with an aqueous solution, it can produce a swollen gel. Due to its high specific heat capacity, this water-based gel can store a large amount of heat generated by an exothermic reaction. Thus, the gel retains heat for a relatively long time (compared to an exothermic reaction conducted without the gel). The gel also extends the duration during which the heated object can be maintained at a relatively constant elevated temperature. Additionally, as the gel-forming composition swells, more surface area of the heated object can be transferred heat to compared to when the gel does not swell.

[0048] The term "superabsorbent polymer" can be any polymer that can swell to 200 grams per gram of dry polymer when exposed to water. Generally, SAP is a three-dimensional network of loosely crosslinked flexible polymer chains that carry dissociable ionic functional groups. The ability of SAP to absorb a specific material (such as water) is determined by the osmotic pressure, the affinity of the polymer for that material, and the rubber elasticity of the polymer.

[0049] The difference between the ionic concentration inside the SAP and the ionic concentration of the surrounding aqueous solution determines the strength of the available osmotic pressure. Thus, the osmotic pressure enables SAP to absorb a large amount of water. Additionally, the affinity of a specific polymer for its surrounding solution also affects the polymer's absorption ability. Therefore, based on the polymer's absorption ability (which is attributed to the surrounding osmotic pressure and the polymer's affinity for water), SAP can absorb a large amount of water and other aqueous solutions without being dissolved by the water molecules via hydrogen bonding, increasing the entropy of the network to cause the SAP to swell significantly.

[0050] Conversely, the factor that inhibits the absorption ability of SAP lies in the gel elasticity resulting from its network structure. The rubber-like elasticity of the polymer increases with the crosslink density of the polymer, where when the rubber elasticity of a given SAP reaches equilibrium with its water absorption ability, the absorption ability of the given SAP reaches its maximum value.

[0051] Examples of SAP can include polyacrylate-based polymers, ethylene alcohol-acrylate-based polymers, PVA-based polymers, or isobutylene-maleic anhydride polymers. Other examples of SAP include polysaccharides such as carboxymethyl starch, carboxymethyl cellulose, and hydroxypropyl cellulose; nonionic types such as polyvinyl alcohol and polyvinyl ether; cationic types such as polyvinyl pyridine, polyvinyl morpholinone, and N,N-dimethylaminoethyl or N,N-diethylaminopropyl acrylate and methacrylate; and carboxyl groups including hydrolyzed starch-acrylonitrile graft copolymers, partially neutralized hydrolyzed starch-acrylonitrile graft copolymers, hydrolyzed acrylonitrile or acrylamide copolymers, and polyacrylic acid.

[0052] Methods for preparing SAP are well known and can be easily optimized to obtain the desired swelling property. For example, SAP can be prepared by polymerizing acrylic acid mixed with sodium hydroxide in the presence of an initiator to form sodium polyacrylate (i.e., "sodium polyacrylate"). Other materials are also used to prepare SAP, which are polyacrylamide copolymers, ethylene maleic anhydride copolymers, crosslinked carboxymethyl cellulose, polyvinyl alcohol copolymers, and crosslinked polyethylene oxide.

[0053] Although there are many types of SAPs on the market, most are lightly cross-linked copolymers of acrylate and acrylic acid, and grafted starch-acrylic polymers prepared by inverse suspension, emulsion polymerization or solution polymerization. Inverse suspension polymerization is commonly used to prepare polyacrylamide-based SAPs and involves dispersing a monomer solution in a non-solvent to form fine monomer droplets with a stabilizer added. Polymerization is then initiated by free radicals from the thermal decomposition of an initiator.

[0054] Particularly suitable SAPs are found to include, for example, AQUA manufactured by Sumitomo Seika Chemical Company (Osaka, Japan). Superabsorbent polymer. For some embodiments, a suitable fast-acting form of AQUA is AQUA 10SH-P. Other polymers available commercially are found to be, for example: CABLOC 80HS, available from Stockhausen, Inc. of Greensboro, North Carolina; 2G-40, available from Emerging Technologies of Greensboro, North Carolina; SANWET IM 1000F, available from Hoechst Celanese of Bridgewater, New Jersey; AQUALIC CA, available from Nippon Shokubai of Osaka, Japan; and SUMIKA GEL, available from Sumitomo Kagaku Kabushiki Kaisha of Japan. Additional SAPs are also commercially available from many manufacturers, such as The Dow Chemical Company (Midland, Michigan) and Chemdal (Arlington Heights, Illinois). Any of the above SAPs can be included as a mixture of two or more polymers, provided that the majority of the polymers (greater than 50%, preferably greater than 70% weight / weight) have an absorption capacity equal to or greater than 200 grams per gram.

[0055] Absorption measurements can be made according to a variety of methods, including the tea bag method, the centrifugation method, and the sieving method. According to the tea bag method, a sample is placed in a bag measuring approximately 5 cm × 5 cm, and the bag is then sealed around its perimeter. The bag is then placed in a dish containing an excess of water or 0.9% NaCl solution, allowing the sample to absorb the solution and freely bulge in the bag for 1 hour or until equilibrium is reached. The bag is then removed to separate the sample from any excess solution and weighed to calculate the bulging capacity. The absorption capacity of the polymer sample can then be calculated according to the following formula:

[0056]

[0057] Where: A s = sample absorbency; Ab = Absorbency of the tea bag material; m m = Weight of the tea bag with the sample after absorption; m b = Weight of the empty, dry tea bag; and m s = Weight of the dry sample.

[0058] In one embodiment, the SAP (or at least a majority of the SAP if it is a mixture of two or more) has an absorption capacity of at least 200 grams / gram, where 1 gram of SAP can absorb up to 200 grams of water. The SAP can also be a fast-acting polymer having an absorption rate of no more than 20 seconds, and more preferably no more than 10 seconds or no more than 5 seconds.

[0059] Encapsulation

[0060] All of the disclosed embodiments can be further processed to include a degree of encapsulation of the components to control the exothermic reaction. For example, one method is to encapsulate the GA particles or the gel-forming composition to both extend its shelf life and control the release of energy when it is exposed to the activation solution. As used herein, "encapsulation" means that at least a portion of the GA or other portions of the gel-forming composition are substantially enclosed within a suitable encapsulating material such that the encapsulating material adheres to the surface of the particles. As used herein, "suitable encapsulating material" or "encapsulant" means a material strong enough to withstand the formulation and manufacturing conditions of the gel-forming composition, which is compatible with the formulation and does not have an adverse effect on its performance, it being noted that extending heat generation does not have an adverse effect. Additionally, the suitable encapsulating material adheres to the composition. The attachment of the encapsulant can occur by covalent chemical bonding or by non-covalent interactions (e.g., ionic, van der Waals, dipole-dipole interactions, etc.).

[0061] As used herein, "microencapsulation" means that the average diameter of the encapsulated component is from about 1 μm to about 1000 μm. If the encapsulated component is oval or asymmetric, the average diameter is measured along the portion of the component having the greatest length. In one embodiment, all or a portion of the foregoing composition can be microencapsulated, and the encapsulated product has an average diameter of from about 1 μm to about 1000 μm, or from about 1 μm to about 120 μm, or from about 1 μm to about 50 μm, and or from about 1 μm to about 25 μm. In another embodiment, the average diameter of the encapsulated product is from about 100 μm to about 800 μm, or from about 500 μm to about 700 μm, such as 600 μm.

[0062] Non-limiting examples of suitable encapsulating materials include polystyrene, methacrylate, polyamide, nylon, polyurea, polyurethane, gelatin, polyester, polycarbonate, modified polystyrene, and ethylcellulose biodegradable polymer matrices. In one embodiment, the encapsulating material is poly(lactide-co-glycolide) (PLG), poly(glycidylmethacrylate) (PGMA), polystyrene, or a combination thereof. In another embodiment, the encapsulating agent is hydroxypropyl methylcellulose. Suitable encapsulating materials may have a molecular weight of from about 5 kDa to about 250 kDa, or from about 200 kDa to about 250 kDa, or from about 50 kDa to about 75 kDa, or from about 10 kDa to about 50 kDa, and / or from about 10 kDa to about 25 kDa.

[0063] It should also be understood that any or all of the alloy components (i.e., both the cathode and the anode), or the cathode and / or anode alone, can be encapsulated with or without an adhesive. By using different combinations of coatings of different components and conventional optimization of known encapsulation techniques, the ideal encapsulation form can be determined based on the use of the composition. For example, for a body wrap intended to obtain a longer-lasting therapeutic benefit, a less soluble coating is required to extend the heat generation time. Alternatively, for drug administration, a more soluble coating is required to achieve a higher temperature over a shorter time span.

[0064] The chemical properties of the coatings described above and their use in various fields such as nanotechnology, energy materials, and the medical field are well known, and such optimization can be easily achieved based on this body of knowledge.

[0065] Adhesive

[0066] In addition to SAP, the gel-forming composition may further include at least one binder, such as a polymer or a plastic. Exemplary binders include natural resins, synthetic resins, gelatin, rubber, poly(vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly(vinyl pyrrolidone), casein, starch, poly(acrylic acid), poly(methyl methacrylic acid), poly(vinyl chloride), poly(methacrylic acid), styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, poly(vinyl acetal) (such as poly(vinyl formal) and poly(vinyl butyral)), poly(ester), poly(urethane), phenoxy resin, poly(vinylidene chloride), poly(epoxide), poly(carbonate), poly(vinyl acetate), poly(olefin), cellulose ester, and poly(amide). The binder may be added to the gel-forming composition as a solution or an emulsion in water or an organic solvent and mixed together using known methods.

[0067] Hydrogen inhibition

[0068] As contemplated herein, gas inhibition, particularly hydrogen inhibition, is viewed relative to a similar or identical uninhibited reaction. In an uninhibited reaction, the gas is freely generated at a known level, a previously known level, or a level calculable based on the reactants. Gas inhibition as contemplated herein refers to a percentage reduction in gas generation and release from an exothermic composition (e.g., gel, foam, etc.) formed relative to the uninhibited reaction. The experimental data provided for the exemplary embodiments herein demonstrate greater than 90% gas inhibition, although higher levels of gas inhibition up to and including 100% gas inhibition are expected. In certain embodiments, gas inhibition is provided between 30% or about 30% and 95% or about 95%. In certain embodiments, gas inhibition is provided at 37% or about 37% or greater than about 37%. In certain embodiments, gas inhibition is provided from about 37% to 93%, 93% or about 93% or greater than about 93%.

[0069] In one embodiment, a composition that inhibits the formation of hydrogen by-products and exotherm of the gel can be prepared from a homogeneous mixture of SAP, one or more GA particles, and a metal having secondary shell or electron orbital bonding characteristics (also referred to as a metal secondary shell). This metal secondary shell can hinder or prevent the formation of hydrogen due to reactions with secondary shell electrons or within an electron-sharing configuration, eliminating hydrogen by-products at the outermost surface of the GA alloy particles. Effectively, the metal secondary shell hinders hydrogen production at the surface level. Generally, most elements can only bond with other elements using electrons from their outer orbitals. These metals with "secondary shell" bonding characteristics can use two outermost shells / electron orbitals (such as the s orbital, d orbital, p orbital, and / or f orbital shared by the electronic structure of these metal secondary shells) to bond with other elements to produce unexpected combinations. In the case of this embodiment, instead of hydrogen atoms being reduced and becoming H2 or molecular hydrogen, this secondary interaction hinders it when it bonds with elemental magnesium atoms, magnesium hydroxide, magnesium oxide, and / or water molecules.

[0070] Exemplary metal secondary shells can include transition metals such as scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, rutherfordium, .

[0071] One embodiment of the metal secondary shell can include manganese dioxide. Manganese dioxide is an effective hydrogen inhibitor, which is relatively inexpensive, easily obtainable, and harmless to the environment, humans, plant, and animal life safety.

[0072] Any metal secondary shell disclosed herein can be combined with GA particles by grinding them together with a ball mill and then stirring the superabsorbent polymer (SAP) material with this composition. In certain embodiments, any one of various commercially available stirrers and mixers (such as drum stirrers, Braun stirrers, belt mixers, blade mixers, V-shaped mixers, batch stirrers, etc.) can be used to produce a homogeneous mixture. The preferred mixer is one that does not overly shear the GA particles, the metal secondary shell, or the SAP. Depending on the type of equipment used, the two main components and any optional components are added to the stirring container sequentially or simultaneously and stirred until a homogeneous mixed product is formed.

[0073] With this gel-forming composition, in the absence of oxygen to activate, the output gas is sharply reduced and heat is safely and effectively generated, substantially without hydrogen by-products. In some embodiments, it has been found that compared with the case where the gel-forming composition does not include a secondary shell, this has inhibited or hindered 90% to 100% of the hydrogen by-products.

[0074] In other embodiments of the composition, the net hindrance of hydrogen gas results in other improvements. For example, typical magnesium-iron alloys react with water to produce a very "metallic smell" because the human olfactory system can detect hydrogen gas as a metallic smell. The typical magnesium-iron alloy reacts with water to produce a very "metallic smell" that can be discerned by the human olfactory system. Although the smell is non-toxic, it can be very unpleasant for some people, especially in the presence of food. The eating experience is related to taste and smell, so an unpleasant smell can ruin the eating experience. While food and eating are one example, the benefit of preventing this metallic smell provides many other benefits and a broader potential use for the base composition. Some embodiments of the composition address this issue by preventing the metallic smell from occurring and by absorbing any other smells into the hydrogel formed by SAP.

[0075] In other embodiments of the composition, to reduce or hinder the "metallic smell" of the magnesium-iron alloy reaction, activated carbon is used as an odor absorbent in combination with the composition. In some embodiments, however, activated carbon may have difficulty absorbing hydrogen by-products, and adding activated carbon to the composition will unexpectedly interact with the "push-pull" or "tug-of-war" between the electrons of the exothermic reaction, causing the orbital shells and hydrogen bond forces to act in a synergistic and antagonistic manner to the SAP gel matrix. In this regard, adding activated carbon can affect the ability of SAP to buffer, control, extend, and achieve a predictable heat distribution. Surprisingly, the addition of activated carbon helps to make the exothermic reaction more efficient and achieve a longer output with a higher heat output. Activated carbon can be present in an amount of about 2% to 25% of the composition.

[0076] Activated carbon can include a combination of graphite materials and other carbon powders of various particle sizes. Generally, the form of activated carbon considered herein is the conductive form of activated carbon. Using a combination of some or all of these modifiers for the electrical interaction of the gel-forming composition is particularly advantageous for the overall efficiency of the exothermic reaction. Specifically, due to the magnetic interaction of the conductive minerals with the above-mentioned electrical / hydrogen bond struggle between SAP and the alloy.

[0077] In other embodiments, an expandable exothermic composition is disclosed that uses magnetite (Fe3O4) in combination with one or more of the electrocouple alloy particles and SAP embodiments described herein. The use of magnetite is particularly advantageous because when activated with an aqueous solution, it can produce an exothermic reaction with a unique heat curve (e.g., generate heat for a longer duration and / or at a higher temperature) without sacrificing the duration of the heat output.

[0078] The activating solution can generally be an aqueous solution, such as water. It is also important to note that the gel-forming composition or the activating solution contains at least one electrolyte, which helps to initiate the electrochemical process required for the exothermic reaction. As used herein, the term "electrolyte" refers to a substance containing conductive free ions. Electrolyte solutions are usually ionic solutions and generally exist as acid, base, or salt solutions. When placed in an aqueous solvent (such as water), salts decompose into their component elements. Examples of preferred electrolytes include potassium chloride, sodium chloride, and calcium chloride.

[0079] The particulate gel-forming composition is tested by measuring the swelling volume and rate, as well as heat generation and retention. If the particulate gel-forming composition swells (volume / volume) at least two-fold, preferably five-fold or even ten-fold, it is considered optimal. If it can reach a temperature of at least 105°F and maintain the temperature at at least 100°F for 1 hour, it is considered "effective".

[0080] In one embodiment, magnesium-iron particles can be prepared by stirring 2% to 20% by weight of iron with 80% to 98% by weight of magnesium in an airtight sealed ball mill.

[0081] In one embodiment, the exothermic particulate gel-forming composition has an absorption capacity greater than 400 g / g.

[0082] In one embodiment, the mixture is formed by mixing the galvanic alloy particles to the superabsorbent polymer in a weight ratio of 20:1 to 5:1. In other embodiments, the mixture is formed by mixing the galvanic alloy particles to the superabsorbent polymer in a weight ratio of approximately 1:1. In other embodiments, the mixture is formed by mixing the superabsorbent polymer to the galvanic alloy particles in a weight ratio of 20:1 to 5:1.

[0083] The air is evacuated with an inert dry gas before milling. Grinding is continued at room temperature or near room temperature (e.g., 15°C to 50°C) until the product is homogeneous. The reactivity of the galvanic alloy product upon contact with a salt solution (e.g., 0.5% to 10% sodium chloride) can be tested by measuring the weight loss, which is mainly due to the emission of water vapor.

[0084] In common embodiments contemplated herein, the composition is adapted to provide minimal or near-zero gas that is generated or released from the composition (referring to the reacted, reacting, formed, gelled / foamed, expanding or expanded, exothermic, etc. composition) during or as a result of an exothermic reaction. In commonly included embodiments, during or as a result of an exothermic reaction, more than 40% or more than about 40%, more than 45% or more than about 45%, more than 50% or more than about 50%, more than 55% or more than about 55%, more than 60% or more than about 60%, more than 65% or more than about 65%, more than 70% or more than about 70%, more than 75% or more than about 75%, more than 80% or more than about 80%, more than 85% or more than about 85%, more than 90% or more than about 90%, or more than 95% or more than about 95% of the gas generated by the exothermic reaction is inhibited and not released from the composition (again, referring to the reacted, reacting, formed, gelled / foamed, expanding or expanded, exothermic, etc. composition).

[0085] Hydrogen by-product isolation

[0086] In another embodiment, GA particles can be mixed or agitated with a superabsorbent polymer and a permanganate or ferrate oxidant (such as lithium permanganate, sodium permanganate, potassium permanganate, lithium ferrate, sodium ferrate, or potassium ferrate) to form a homogeneous mixture. In this regard, a self-heating composition based on the oxidation reaction of GA particles (such as magnesium-iron) is disclosed for oxidizing or eliminating hydrogen within the composition before the hydrogen gas by-product can escape. As previously described, the gel-forming composition can be activated when contacted with an activating solution (such as an aqueous electrolyte solution, e.g., water or a salt solution) in the absence of air.

[0087] Adding a permanganate or ferrate oxidant (such as potassium permanganate or potassium ferrate) to the mixture of GA and SAP will produce an oxygen source that can combine with the hydrogen released by the Mg-Fe alloy before the hydrogen is converted to hydrogen gas and escapes. Subsequently, water and hydrogen peroxide (H2O2) can be produced in this reaction, which in turn feeds back a water source to the Mg-Fe alloy to assist its oxidation-reduction reaction. In this embodiment, the hydrogen peroxide ultimately decomposes into water and another oxygen molecule source. In other words, the H2 gas by-product can be captured and converted to water. Although potassium permanganate or potassium ferrate may be preferred, other reducible substances can be used within the scope of the present disclosure.

[0088] In certain embodiments of the composition, the use of such an oxidizer with the gel may result in purple staining or discoloration, which may be attributed to, for example, potassium permanganate. For certain applications, such as heating food, this may be a discouraging by-product because the food container may come into contact with the permeable sachet and the stain will pass through the permeable sachet onto the food container and thus onto the hands of the person eating the food. However, such discoloration and staining can be addressed by gelation of the composition. For example, the rubbery thick hydrogel shown in certain embodiments can isolate the liquid before it stains or discolors the surrounding materials. Since the stain is "trapped" or isolated by the gel, the transfer of the discolored solution can be reduced or eliminated. At the same time, the oxygen generated by these reducing substances can flow through or "bubble through" the gel, enabling it to combine with free hydrogen molecules, which can occur within the gel.

[0089] Synthesis and activation via the liquid activator can occur within a sealed container to allow time for any stain to be absorbed and isolated within the composition forming the gel. In certain embodiments, one or more layers of the container may optionally be permeable while other layers may optionally be impermeable.

[0090] In certain embodiments, the heat generated within the container causes the container to expand due to the generation of air and the outflow of water vapor. Therefore, the container must be vented to the external atmospheric pressure. This venting can be carried out through a panel of permeable material (such as non-woven (or woven) fabric, perforated plastic lid, etc.). The permeable layer can be disposed above a chamber in which the composition is in contact with the aqueous solution. To further delay the leakage of the stained solution, a layer of water-soluble film or coating can also be applied to the inner side of the permeable layer adjacent to the composition. Non-limiting examples of water-soluble materials can be polyvinyl alcohol (PVA or PVOH), but any water-soluble coating or film can be used as needed or required. In other embodiments, the container may include a steam pressure valve. These "valves" can discharge the pressure of steam or hot air at a predetermined level. In certain embodiments, the delay level is a programmed time to ensure that all liquid stains are isolated.

[0091] By delaying the discharge of steam and heated by-product gases from the sealed container, further mixing and combination of the free oxygen introduced by the above reducible substances and the free hydrogen generated by the oxidation of the GA alloy may occur. Subsequently, the hydrogen by-product can be further eliminated. Additionally, in certain embodiments, as the heat and moisture of the gel and steam penetrate the water-soluble coating, it can quickly eliminate the pressure within the container before it accumulates to a significant level. In turn, the pressure can be released through the permeable layer. This delay can also ensure the removal of all free hydrogen.

[0092] Exothermic gel without hydrogen by-products

[0093] In another embodiment, the catalyst for peroxide decomposition can be mixed or agitated with a buffering agent (such as the aforementioned SAP) to form a mixture (such as a powder mixture) that is uniform or homogeneous. When the catalyst is combined with peroxide decomposition and a buffering agent, an exothermic reaction that does not produce hydrogen as a by-product can be induced. Other buffering agents are contemplated for use with the composition, including particles from a mixture of compressed sponges, clay particles, and other synthetic and modified natural materials. Some synthetic superabsorbent polymer materials contemplated for use as buffering agents with the composition include: ammonium salts of alkali metals and poly(acrylic acid) and poly(methacrylic acid), poly(acrylamide), poly(vinyl ether), maleic anhydride copolymers having vinyl ether and α-olefins, poly(vinylpyrrolidone), poly(vinylmorpholinone), poly(vinyl alcohol), and mixtures and copolymers thereof. However, the composition is not limited thereto, and other superabsorbent materials contemplated for use with the composition include other natural and modified natural polymers, such as hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, methyl cellulose, chitosan, carboxymethyl cellulose, hydroxypropyl cellulose, and certain natural gums, such as alginates, xanthan gum, locust bean gum, etc.

[0094] The amount and properties of the buffering agent used in conjunction with the catalyst for peroxide decomposition can be selectively varied to control and / or stabilize the exothermic reaction associated with the composition. The buffering agent can also be selectively varied to regulate the calorific value output of the composition at a higher or lower rate, for example, by inhibiting a carbonate solution with, for example, magnesium sulfate. Subsequently, this affects the mechanism of the composition reaction such that the decomposition of hydrogen peroxide can be flattened. This is particularly advantageous because it makes the decomposition more efficient, as it has also been found that making the stable exothermic reaction less efficient or less stable is a method of controlling or altering the reaction output.

[0095] In these embodiments, the exothermic expandable composition is activated upon contact with an activator solution containing a peroxide (such as hydrogen peroxide (H2O2)). For example, the peroxide decomposition catalyst can be mixed with SAP and activated with hydrogen peroxide to produce an exothermic reaction. The peroxide decomposition catalyst can be any peroxide decomposition catalyst suitable for mixing with SAP or one or more other buffering agents. For example, the peroxide decomposition catalyst can be manganese oxide, an iron salt (such as iron chloride), or an enzyme (such as catalase).

[0096] In certain embodiments, the encapsulation of the catalyst can affect the heat output curve, delay, or prolong the reaction, depending on the solubility of the encapsulation. Other methods of affecting the heat output can include varying the catalyst, which includes manganese oxide (MnO2), zinc oxide (ZnO), copper oxide, PhO2, lead dioxide, red iron oxide (III), peroxidase, potassium iodide, iron chloride, etc.

[0097] The composition is particularly advantageous because the exothermic reaction associated with the composition is persistent, safe, controlled, and the activator solution has a much lower freezing point than a salt solution or water. This is particularly useful in operating environments where the temperature can drop significantly, such as at higher altitudes or sub-zero conditions. Preferably, 35% by weight of hydrogen peroxide can be used for a freezing point of -31 °C, however, other weight percentages can be used as needed or required. Additionally, because the reaction is catalytic, the presence of peroxide decomposition catalysts can be minimized in the SAP mixture or in a mixture with one or more other buffering agents. In a preferred embodiment, a homogeneous mixture of manganese oxide and SAP can be treated with a peroxide solution to produce an exothermic reaction that produces only water and oxygen.

[0098] The gel-forming compositions of the present disclosure are useful because they form a swollen gel or foam matrix upon hydration and establish a balance between energy release and energy management. In certain embodiments, this is caused by the relationship between the SAP and other active ingredients in the compositions disclosed herein. While not wishing to be bound by any theory of operation, the SAP rapidly absorbs the aqueous solution, which limits the reactivity of the remaining components of the composition. As the moisture transfers from the gel component to the remaining components, a controlled reaction then occurs. The reaction releases heat, which is transferred back into the gel, which stores the heat rather than allowing it to escape into the air in the form of heated gas. This synergistic heat storage and distribution system provides benefits for commercial applications such as medical, therapeutic, and cosmetic treatments. Since the gel-forming particles swell upon hydration, they can be incorporated into any of a number of different devices, and when they swell, they swell where needed, which can be used to produce a uniform exothermic gel blanket, thereby maximizing surface area contact and eliminating areas of non-uniform heat. The peroxide decomposition rate can be altered, for example, by adding and varying sodium carbonate solution, and relatively high concentrations of magnesium in salt or ionic form (e.g., magnesium sulfate).

[0099] In the following examples, the various conditions such as weight ratios, mixing times, and other data points can be easily optimized for a particular use. For example, in consumer product applications, it is generally desirable to provide a composition that achieves a higher temperature than a medical product used in contact with the skin.

[0100] Example 1

[0101] MgFe Example, with no hydrogen inhibition

[0102] In one embodiment, the galvanic alloy material includes 0.5 grams of MgFe and 0.5 grams of SA60S. The galvanic alloy and SAP (SA60S) mixture is placed in a test tube, and 5 grams of 3% saline solution is added. A stopper is set up, which forces the gas discharged from the exothermic reaction to enter a flask completely filled with water through a pipe. The water is displaced into a beaker. The amount of water displaced by the gas evolution is recorded. Test 1 shows that 303.2 grams of water is displaced, Test 2 shows that 305.6 grams of water is displaced, Test 3 shows that 298.7 grams of water is displaced, Test 4 shows that 301.2 grams of water is displaced, and Test 5 shows that 304.6 grams of water is displaced.

[0103] Example 2

[0104] A. Un-ground MnO2 composition mixture, hydrogen inhibition

[0105] In one embodiment, galvanic alloy particles, SAP, and MnO2 are prepared by mixing them together in a mixing device to form a powder mixture. The material includes 0.5 grams of MgFe, 0.5 grams of SA60S, and 0.5 grams of MnO2. The powder mixture is placed in a test tube, and 5 grams of 3% saline solution is added. A stopper is set up, which forces the gas discharged from the exothermic reaction to enter a flask completely filled with water through a pipe. The water is displaced into a beaker. The amount of water displaced by the gas generation is recorded. Compared with Example 1 without inhibition, the gas generated is about 62.9%, and about 37% of gas inhibition is produced.

[0106] B. Ground MnO2 composition mixture, hydrogen inhibition

[0107] In one embodiment, galvanic alloy particles and SAP are prepared by alloying MgFe and MnO2 using a high-speed ball mill and combining them with SAP (SA60S). The material includes 0.5 grams of MgFe / MnO2 alloy mixed with 0.5 grams of SA60S. The MgFe / MnO2 alloy is mixed with SAP. The mixed MgFe / MnO2 alloy and SAP are placed in a test tube, and 5 grams of 3% saline solution is added. A stopper is set up, which forces the gas discharged from the exothermic reaction to enter a flask completely filled with water through a pipe. The water is displaced into a beaker. The amount of water displaced by the gas generation is recorded. The results show that most of the gas generated by the reaction is inhibited.

[0108] Example 3

[0109] KMnO4 potassium permanganate composition mixture, hydrogen inhibition

[0110] In one embodiment, the galvanic alloy particles, SAP, and KMnO4 are prepared by mixing them together in a mixing device to form a powder mixture. The galvanic alloy material includes 0.5 grams of MgFe, 0.5 grams of SA60S, and 0.5 grams of KMnO4. The powder mixture is placed in a test tube, and 5 grams of a 3% saline solution is added. A stopper is set up, which forces the gas discharged by the exothermic reaction to enter a flask completely filled with water through a pipe. The water is displaced into a beaker. The amount of water displaced by the gas generation is recorded. Compared with the non-inhibited Example 1, the gas generated is about 6.8%, and about 93.2% of the gas generation is inhibited.

[0111] It should be understood that those skilled in the art can make many other changes to the details, materials, steps, and component arrangements that have been described and illustrated herein to explain the nature of the invention without departing from the principles and scope of the invention as set forth in the appended claims.

[0112] Therefore, the definitions of the terms or elements in the following claims are defined in this specification to include not only the combinations of the elements literally set forth. It is also contemplated that two or more elements of any one element in the following claims can be equivalently replaced, or it can be contemplated that a single element can replace two or more elements in the claims. Although the above elements can be described as acting in certain combinations and even initially claimed as such, it should be clearly understood that one or more elements from the claimed combination can be removed in some cases, and the claimed combination can be directed to a sub-combination or a variant of one or more sub-combinations.

[0113] Non-substantive changes to the claimed subject matter that are considered by those of ordinary skill in the art, whether now known or later devised, are expressly contemplated as being equivalent within the scope of the claims. Therefore, obvious substitutions now or later known to those of ordinary skill in the art are defined as being within the scope of the defined elements. Accordingly, the claims are to be understood to include the specific matter set forth above and described, equivalents in concept, obvious substitutions, and matter that incorporates the essential idea of the embodiments.

[0114] The foregoing description includes examples of one or more embodiments. Of course, for the purpose of describing the foregoing embodiments, it is not possible to describe every conceivable combination or method, but those of ordinary skill in the art will recognize that many other combinations and permutations of the various embodiments are possible. Accordingly, the described embodiments are intended to cover all such changes, modifications, and variations that fall within the spirit and scope of the appended claims. In addition, for the scope of the use of the term "comprising" in a specific specification or claim, such a term is intended to be inclusive in a manner similar to the term "including" as explained when used as a transitional word in a claim.

Claims

1. An expandable, exothermic, gel-forming composition comprising: First and second galvanic alloy particles; A metal secondary shell composed of at least one transition metal having electron orbital bonding characteristics; and A superabsorbent polymer; Wherein the first and second galvanic alloy particles, the metal secondary shell, and the superabsorbent polymer are mixed with each other; Among them, When the gel-forming composition is exposed to water and an electrolyte, it is adapted to form an exothermic gel by expanding as the gel-forming composition hydrates, and to produce an oxygen-independent exothermic reaction that generates heat for a predetermined duration; Wherein the metal secondary shell is adapted to inhibit hydrogen by-products generated by the exothermic reaction by combining oxygen generated by the metal secondary shell with hydrogen by-products of the exothermic reaction within the exothermic gel.

2. The composition according to claim 1, wherein the metal secondary shell comprises one or more of the following transition metals, said transition metals comprising: Scandium, titanium, vanadium, and / or chromium.

3. The composition according to claim 1, wherein the metal secondary shell comprises one or more of the following transition metals, said transition metals comprising: Yttrium, niobium, molybdenum, technetium, and / or ruthenium.

4. The composition according to claim 1, wherein the metal secondary shell comprises one or more of the following transition metals, and the transition metals include: Palladium, cadmium, tungsten, rhenium, and / or osmium.

5. The composition according to claim 1, wherein the metal secondary shell comprises one or more of the following transition metals, said transition metals including: Mercury, Rutherfordium, and / or 6. The composition according to claim 1, wherein a powder mixture is formed from the first and second galvanic alloy particles mixed with the superabsorbent polymer.

7. The composition according to claim 1, wherein the transition metal of the secondary shell is manganese dioxide.

8. The composition according to claim 1, further comprising: activated carbon, which is mixed with the first and second galvanic alloy particles, the secondary shell, and the superabsorbent polymer, Among them, The activated carbon is mixed with or forms an alloy with magnetite, and the activated carbon accounts for 2% to 25% of the total weight of the exothermic gel-forming composition, and Wherein the activated carbon absorbs odors generated by the exothermic reaction during gel formation.

9. The composition according to claim 1, further comprising: an electrolyte comprising sodium chloride or calcium chloride, wherein the superabsorbent polymer has an absorption capacity of at least 200 g / g, and wherein the superabsorbent polymer is capable of absorbing water without being dissolved by the solvation of water molecules via hydrogen bonds.

10. The composition according to claim 1, wherein the first and second galvanic alloy particles comprise magnesium and iron.

11. The composition according to claim 10, wherein the superabsorbent polymer is sodium polyacrylamide.

12. The composition according to claim 1, wherein the composition further includes potassium permanganate or potassium ferrate.

13. The composition according to claim 1, wherein the galvanic alloy particles are formed from a mixture of 2% to 20% by weight of iron and 80% to 98% by weight of magnesium.

14. The composition according to claim 1, which is formed by mixing the galvanic alloy particles and the superabsorbent polymer at a weight ratio of 20:1 to 5:

1.

15. The composition according to claim 1, wherein the galvanic alloy particles are microencapsulated with a polymer.

16. The composition according to claim 15, wherein the polymer is hydroxypropyl methylcellulose.

17. The composition according to claim 1, wherein the galvanic alloy particles are encapsulated in an exothermic gel formed from a superabsorbent polymer, and wherein, The predetermined duration is at least one hour.

18. The composition according to claim 1, wherein by combining oxygen generated by the metal secondary shell with hydrogen by-products of the exothermic reaction, more than about 95% of the hydrogen generated by the exothermic reaction is inhibited.

19. A method for inhibiting hydrogen by-products in an exothermic gel, comprising: forming an exothermic gel by exposing the exothermic composition to water and an electrolyte to produce an oxygen-independent exothermic reaction that generates heat for a predetermined duration, the exothermic composition comprising: first and second galvanic alloy particles; a metal secondary shell composed of at least one transition metal having electron orbital bonding characteristics; and a superabsorbent polymer; and inhibiting hydrogen by-products generated by the exothermic reaction in the exothermic gel by combining oxygen generated by the metal secondary shell with hydrogen by-products of the exothermic reaction.

20. The method according to claim 19, further comprising: As the exothermic composition hydrates, the exothermic gel swells.

21. The method according to claim 19, further comprising: Mixing the first and second galvanic alloy particles, the metal secondary shell, and the superabsorbent polymer with each other to form a homogeneous powder mixture.

22. The method according to claim 21, wherein the mixing is carried out by a mixing device.

23. The method according to claim 19, wherein the step of suppressing hydrogen by-products comprises: Oxidizing hydrogen by-products in an exothermic gel based on the oxidation reaction of galvanic alloy particles.

24. The method according to claim 19, wherein the metal secondary shell comprises one or more of the following transition metals, and the transition metals include: Scandium, titanium, vanadium, and / or chromium.

25. The composition according to claim 19, wherein the metal secondary shell comprises one or more of the following transition metals, said transition metals comprising: Yttrium, niobium, molybdenum, technetium, and / or ruthenium.

26. The composition according to claim 19, wherein the metal secondary shell comprises one or more of the following transition metals, said transition metals comprising: Palladium, cadmium, tungsten, rhenium, and / or osmium.

27. The composition according to claim 19, wherein the metal secondary shell comprises one or more of the following transition metals, said transition metals comprising: Mercury, rutherfordium, and / or 28. The method according to claim 19, wherein the step of suppressing hydrogen by-products comprises: Inhibiting about 95% of hydrogen by-products generated by the exothermic reaction in the exothermic gel.

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