WO1999000078A1 - Element chauffant thermosensible - Google Patents

Element chauffant thermosensible Download PDF

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Publication number
WO1999000078A1
WO1999000078A1 PCT/JP1998/002889 JP9802889W WO9900078A1 WO 1999000078 A1 WO1999000078 A1 WO 1999000078A1 JP 9802889 W JP9802889 W JP 9802889W WO 9900078 A1 WO9900078 A1 WO 9900078A1
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WO
WIPO (PCT)
Prior art keywords
temperature
heating element
heat
hydrogel
sensitive
Prior art date
Application number
PCT/JP1998/002889
Other languages
English (en)
Japanese (ja)
Inventor
Hiroshi Yoshioka
Yuichi Mori
Yoshizo Minato
Original Assignee
M & M Laboratory Co., Ltd.
Ferric Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by M & M Laboratory Co., Ltd., Ferric Inc. filed Critical M & M Laboratory Co., Ltd.
Priority to AU79347/98A priority Critical patent/AU7934798A/en
Priority to JP50544499A priority patent/JP3978474B2/ja
Publication of WO1999000078A1 publication Critical patent/WO1999000078A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F7/00—Heating or cooling appliances for medical or therapeutic treatment of the human body
    • A61F7/02—Compresses or poultices for effecting heating or cooling
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F7/00—Heating or cooling appliances for medical or therapeutic treatment of the human body
    • A61F7/02—Compresses or poultices for effecting heating or cooling
    • A61F2007/0203—Cataplasms, poultices or compresses, characterised by their contents; Bags therefor
    • A61F2007/0206—Cataplasms, poultices or compresses, characterised by their contents; Bags therefor containing organic solids or fibres
    • A61F2007/0209—Synthetics, e.g. plastics
    • A61F2007/0214—Polymers, e.g. water absorbing
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F7/00—Heating or cooling appliances for medical or therapeutic treatment of the human body
    • A61F7/02—Compresses or poultices for effecting heating or cooling
    • A61F2007/0203—Cataplasms, poultices or compresses, characterised by their contents; Bags therefor
    • A61F2007/0215—Cataplasms, poultices or compresses, characterised by their contents; Bags therefor containing liquids other than water
    • A61F2007/0219—Gels

Definitions

  • the present invention relates to a heating element which can be suitably used for heating or not heating a surface delicate to temperature (for example, the surface of a living body). More specifically, the present invention relates to a method for detecting a temperature to prevent a runaway of an exothermic reaction. It relates to a temperature-sensitive heating element that has the function of preventing itself.
  • the heating element of the present invention can be particularly preferably used as a "disposable body warmer" for use in medicine or medical care, home use, and leisure use, as a heat-sealing agent, or as a heat-sensitive adhesive such as heat plus Yuichi. .
  • a hydrogel such as a crosslinked product of polyacrylate, which has a high water-retaining ability, which is recently called a superabsorbent resin, as the water-retaining agent.
  • the temperature of the exotherm of the body warmer is controlled by adjusting the components, composition and filling amount of the chemical exothermic agent, or by adjusting the ventilation holes of the storage bag.
  • An object of the present invention is to provide a temperature-sensitive heating element which has solved the above-mentioned disadvantages of the prior art.
  • Another object of the present invention is to provide a temperature-sensitive heating element that can reliably avoid the danger of low-temperature burns and the like.
  • Still another object of the present invention is to provide a temperature-sensitive heating element capable of sensing the temperature itself and controlling the heating temperature more precisely. Disclosure of the invention
  • thermosensitive heating element of the present invention is based on the above findings, and more specifically, is composed of at least water and a hydrogel-forming polymer, and its equilibrium water absorption capacity decreases with increasing temperature. It is characterized by containing thermosensitive hydrogel.
  • a heating member including a bag-shaped member and a temperature-sensitive heating element disposed inside the bag-shaped member; wherein the temperature-sensitive heating element includes at least water;
  • a heat-generating member comprising a thermosensitive hydrogel made of a polymer having a mouth-gel structure and having a reduced equilibrium water absorption capacity with an increase in temperature.
  • the storage bag had minute holes such as pinholes or cracks, it was difficult to detect these minute holes with the naked eye, but the effect was serious. That is, since the heating element itself does not have the function of “temperature control”, it is difficult to avoid the danger that the heating element excessively generates heat due to the presence of the micropores and causes serious results (low-temperature burn). Also, due to the limited air flow, the initial heat generation rate was very slow, and it took a long time to reach the target temperature.
  • thermosensitive hydrogel since a storage bag for limiting the ventilation rate is not essential, oxygen necessary for the exothermic reaction is sufficiently and quickly supplied to the heating element, The initial heat generation rate is high, and it can be configured to quickly reach the target temperature.
  • the thermosensitive gel when the heat generation proceeds and reaches a predetermined temperature, the thermosensitive gel with a thermosensitive mouth opening based on a decrease in the equilibrium water absorption capacity of the polymer constituting the gel. It is presumed that the water is released from the heater, thereby cooling the heating element and preventing excessive heating of the heating element.
  • FIG. 1 is a schematic cross-sectional view showing an example of an embodiment of the present invention in which a heating element 1 using a temperature-sensitive hydrogel is disposed in a bag-shaped member 2.
  • FIG. 2A is a schematic graph for explaining the temperature control mechanism of the temperature-sensitive heating element of the present invention
  • FIG. 2B is an enlarged view of a portion P i -P 2 of FIG. 2A.
  • FIG. 3 is a graph showing an example of a time-temperature change curve obtained in an example described later.
  • FIG. 4 is a graph showing an example of the relationship between the equilibrium water absorption capacity of a hydrogel and temperature.
  • FIG. 5 is a graph showing an example of a time-temperature change curve obtained in the example.
  • FIG. 6 is a graph showing an example of a time-temperature change curve obtained in the example.
  • FIG. 7 is a graph showing an example of a time-temperature change curve obtained in the example.
  • FIG. 8 is a graph showing an example of a time-temperature change curve obtained in the example.
  • FIG. 9 is a graph showing an example of a time-temperature change curve obtained in the example.
  • the temperature-sensitive heating element of the present invention has an equilibrium absorption in the heating section as the temperature increases. It contains at least a thermo-sensitive hydrogel whose water magnification decreases.
  • the thermo-sensitive hydrogel comprises at least water and a hydrogel-forming polymer.
  • the ratio (Tm / Ta) between the maximum temperature (Tm) and the average temperature (Ta) of the thermosensitive heating element of the present invention is preferably 1.15 or less, more preferably 1.10 or less (particularly, 1.08 or less). Further, the difference between these temperatures (Tm-Ta) is preferably 8 ° C. or less, more preferably 5 ° C. or less (especially 3 ° C. or less).
  • thermosensitive heating element the maximum temperature (Tm) and the average temperature (Ta) of the thermosensitive heating element can be suitably measured by the following method.
  • a glass beaker (diameter 3.0 cm, height 4.4 cm), prepare about 6 g of the heating element (or heating agent) as a sample to be measured, and place the beaker on a styrene foam plate (size ⁇ 20 x 30 cm, thickness: 20 mm).
  • the upper part of the beaker was covered with filter paper (No. 2 filter paper, manufactured by Toyo Roshi Kaisha, Ltd.), and the temperature of the bottom of the beaker was adjusted using a bead type probe (Yokogawa Electric Co., Ltd.) arranged between the bottom and the styrene foam plate.
  • thermocouple thermometer (trade name: Model 2455, manufactured by Yokogawa Electric Co., Ltd., Model 2459-07) (heating agent is agitated every 30 minutes). With such a measurement system, immediately after the start of measurement (to), even if the heating agent is stirred, no remarkable temperature rise (3 ° C or more) is observed, and the thermometer indicates 38.5 ° C. Temperature measurement is continuously performed until time (t1).
  • the highest temperature is defined as the maximum temperature Tm.
  • this temperature measurement method even when the heating element arranged in the “bag-shaped member” is to be measured, only the main body of the heating element, that is, only the constituent components in the bag-shaped member are measured. It shall be taken out and subjected to the above temperature measurement method. In this specification, this temperature measurement method is used only for the purpose of measuring the maximum temperature (Tm) and the average temperature (Ta), and is used for other purposes (for example, as described later). This is not used for (Temperature measurement in Examples).
  • the “hydrogel” refers to a gel containing at least a crosslinked or network structure composed of a polymer and water (supported or retained in the structure) (dispersed liquid).
  • the “dispersed liquid” retained in the crosslinked or network structure is not particularly limited as long as it is a liquid containing water as a main component. More specifically, for example, the dispersion liquid may be water itself, or any aqueous medium such as an aqueous solution and / or a water-containing liquid (for example, a mixed liquid of water and a monohydric or polyhydric alcohol). It may be.
  • thermosensitive hydrogel used in the present invention is composed of a “thermosensitive hydrogel-forming polymer” having a property that its equilibrium water absorption capacity decreases with increasing temperature.
  • the thermosensitive hydrogel-forming polymer has a negative temperature coefficient of solubility in water and / or its aqueous solution has a crosslinked structure with a polymer compound having a lower critical solution temperature (LCST). It can be obtained by giving or introducing.
  • LCST refers to the temperature at which a uniform aqueous polymer solution separates into two phases, an aqueous phase and a polymer phase, due to an increase in temperature (Heskins, M., et al., J. Macromol. Sc i. Chem. A 2 (8); 1441, 196 8).
  • Temperature-sensitive hydrogel-forming high molecule '' obtained by crosslinking a polymer compound having LCST absorbs water in a temperature range lower than the LCST and swells to form a hydrogel. Its equilibrium water absorption ratio That is, water is discharged to the outside and gradually shrinks, and the LCST shrinks remarkably discontinuously. This behavior of thermosensitive hydrogel is observed thermoreversibly, and when the temperature decreases, it absorbs water again and swells. The driving force of this temperature-dependent reversible swelling-shrinking behavior of hydrogels is attributed mainly to hydrophobic interactions, and is theoretically understood by Tanaka et al. As a volume phase transition phenomenon of gels (eg, Tanaka , T, et al., Phys. Rev. Lett., 55; 2455, 1985).
  • the heating element of the present invention including the above-mentioned temperature-sensitive hydrogel as the heating section, when the heat generation proceeds and reaches a predetermined temperature, water is released from the temperature-sensitive opening gel and the heating element is cooled. Prevent the heating element from overheating.
  • the thermosensitive hydrogel absorbs water in the vicinity of the outside, so that cooling due to evaporation of water is suppressed, and the temperature is prevented from excessively lowering.
  • the temperature-sensitive heating element of the present invention senses the temperature itself and controls the heating temperature more precisely, so that it is possible to avoid the danger of low-temperature burns and the like.
  • the temperature-sensitive hydrogel used in the present invention is a temperature-sensitive hydrogel having a property that its equilibrium water absorption ratio decreases with increasing temperature.
  • thermosensitive hydrogel in a predetermined aqueous medium at a predetermined temperature is measured as follows.
  • thermosensitive hydrogel-forming polymer An amount (W ig) of the dried thermosensitive hydrogel-forming polymer is weighed, and an excess amount (for example, a weight of 1.5 times or more of the expected water absorption of the thermosensitive hydrogel-forming polymer) is measured. It is immersed in a medium and left in a thermostat at a predetermined temperature for 2 days (48 hours) to swell the thermosensitive hydrogel-forming polymer. After removing the excess aqueous medium by filtration or centrifugation at the predetermined temperature, The weight (W 2 g) of the water-swelled thermosensitive hydrogel is measured, and the equilibrium water absorption capacity in the aqueous medium at the specified temperature is determined by the following equation.
  • the equilibrium water absorption ratio has a substantially constant minimum value at a temperature higher than the above-mentioned LCST, and increases in a temperature region lower than the LCST with decreasing temperature.
  • the equilibrium water absorption capacity greatly changes in a narrow temperature range.
  • a temperature 2 ° C lower than LCST is used. Is preferably 1.2 or more, more preferably 1.5 or more (particularly 2 or more).
  • Examples of the “polymer compound having LCST” in the present invention include poly N-substituted acrylamide derivatives, poly N-substituted acrylic amide derivatives, and these poly N-substituted acrylamide derivatives / poly N-substituted methacrylamide copolymers, polyvinyl methyl ether, polypropylene oxide, polyethylene oxide, etherified methylcellulose, polyvinyl alcohol partially acetylated, etc., as required, various copolymers and / or It can be suitably used as a mixture.
  • poly N-substituted acrylamide derivatives or poly N-substituted methacrylamide derivatives, or N-substituted acrylamide derivatives / poly N-substituted methacrylamide copolymers are particularly preferred in the present invention. It can be used preferably.
  • polymer compound preferably used in the present invention are listed in ascending order of LCST: poly-N-acryloylbiperidine; poly-N-n-propylmethacrylamide; poly-N-isopropylacrylamide. N-N-N-Getyl acrylamide; Poly-N-isopropylmethyl acrylamide; Poly-N-cyclopropyl acrylamide; Poly-N —Acryloylpyrrolidine; poly-N, N-ethylmethylacrylamide; poly-N-cyclopropylmethacrylamide; poly_N-ethylacrylamide.
  • the above polymer may be a homopolymer (homopolymer), or may be a copolymer of a monomer constituting the polymer with another monomer.
  • the other monomer constituting such a copolymer any of a hydrophilic monomer and a hydrophobic monomer can be used.
  • hydrophilic monomer examples include N-vinylpyrrolidone, vinyl pyridine, acrylamide, methacrylamide, N-methylacrylamide, hydrocyanic acid methacrylate, hydrocyanic acid acrylate, and hydrocyanic acid acrylate.
  • hydroxymethyl methacrylate acrylic acid having an acidic group, methacrylic acid and salts thereof, vinylsulfonic acid, styrenesulfonic acid, etc .; and N, N- having a basic group Examples include, but are not limited to, dimethylaminoethyl methacrylate, N, N-dimethylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylamide, and salts thereof.
  • the hydrophobic monomers include acrylate derivatives and methacrylate derivatives such as ethyl acrylate, methyl methacrylate, butyl methacrylate and glycidyl methacrylate, and N-substituted alkyls such as N-n-butyl methyl acrylamide.
  • examples include, but are not limited to, methacrylamide derivatives, vinyl chloride, acrylonitrile, styrene, vinyl peroxylate, and the like.
  • LCST is the equilibrium water absorption of the hydrogel-forming polymer of the present invention. It can be regarded as one of the factors that determine the temperature dependence of the rate. That is, by selecting the “copolymer component” as described above,
  • the LCST of the polymer compound having an LCST used in the present invention can be appropriately selected depending on the purpose of use of the heating element, but it should be 30 ° C or more and 70 ° C or less in the aqueous medium contained in the temperature-sensitive hydrogel. Is preferred. In particular, when used for thermal patches for the purpose of preventing low-temperature burns, the temperature should be 35 ° C or more and 50 ° C or less, and more preferably 40 ° C or more and 45 ° C or less. More preferred.
  • the temperature-sensitive hydrogel will release most of the water in a low temperature environment (for example, in an environment at a temperature of 30 ° C or lower), increasing the tendency to inhibit heat generation. .
  • the LCST exceeds 70 ° C, the release of water from the thermosensitive hydrogel in a high-temperature environment (for example, in an environment at a temperature of 45 ° C or higher) decreases, and the effect of suppressing heat generation is insufficient. Becomes
  • a method for imparting or introducing a crosslinked structure to a polymer compound as described above a method for introducing a crosslinked structure when polymerizing a monomer to be provided with the polymer compound, and a method for terminating the polymerization of the monomer
  • the former (cross-linking at the time of monomer polymerization) method can be usually carried out by copolymerizing a bifunctional monomer (or a monomer having three or more functional groups).
  • bifunctional monomers such as N, N-methylenebisacrylamide, hydroxyshethyl dimethacrylate, and divinylbenzene can be suitably used.
  • the latter method (introduction of cross-linking after completion of monomer polymerization) is usually carried out by light, electron beam, It can be carried out by forming cross-links between molecules by irradiation with a ray.
  • such a latter method involves, for example, crosslinking a polyfunctional molecule having a plurality of functional groups (for example, isocyanate groups) capable of binding to a functional group (for example, an amino group) in a polymer compound. It can also be carried out by crosslinking the polymer compound by using it as an agent.
  • the equilibrium water absorption of the hydrogel-forming polymer of the present invention depends on the above-mentioned crosslinked structure, particularly the crosslink density. Tends to be large.
  • the effect of crosslink density on the equilibrium water absorption ratio in the high temperature region higher than LCST tends to be relatively small, so that the lower the crosslink density, the greater the temperature dependence of the equilibrium water absorption ratio.
  • such a “crosslink density” is changed by, for example, changing the copolymerization ratio of a bifunctional monomer.
  • the latter method for example, light, an electron beam, a By changing the amount of irradiation, it is possible to arbitrarily control to a desired degree.
  • the crosslink density is about 0.02 mol% to about 10 mol%, and more preferably about 0.05 mol 1 to about 4 mol 1, in terms of the molar ratio of branch points to all monomers. Preferably it is in the% range.
  • the copolymerization weight ratio of the difunctional monomer to all monomers is about Q / ⁇ to about 3 wt.% (More preferably, about 0.05 wt.% To about 1.5 wt.%).
  • the crosslink density exceeds about 1 Omo 1% in the present invention, the temperature dependence of the equilibrium water absorption capacity of the hydrogel-forming polymer of the present invention is reduced, so that the hydrogel-forming The effect of water absorption and water release of the polymer becomes small.
  • the crosslink density is less than about 0.02 mo 1%, the mechanical strength of the polymer having a high gelling ability becomes weak, making it difficult to handle and simultaneously swelling with temperature change. The possibility of mechanical damage during the shrinkage process is high. It will be good.
  • the crosslink density (molar ratio of branch points to all monomers) as described above can be determined by, for example, 13 C-NMR (nuclear magnetic resonance absorption) measurement, IR (infrared absorption spectrum) measurement, or elemental analysis. It can be quantified.
  • thermosensitive hydrogel or the hydrogel-forming polymer used in the present invention is not particularly limited, and can be appropriately selected depending on the type of the heating element, the method of use, and the like.
  • the shape of the hydrogel or polymer can be various shapes such as, for example, a microscopic bead shape, a fiber shape, a film shape, and an amorphous shape.
  • the size of the hydrogel or polymer in the present invention is determined by the following: the process of changing the equilibrium water absorption ratio of the hydrogel-forming polymer with respect to temperature change, that is, the ability to follow the temperature during the swelling and shrinking processes. It is preferable to increase the surface area per unit volume of the hydrogel or polymer, that is, to decrease the size per hydrogel or polymer (for example, one particle).
  • the size of the hydrogel or polymer in the present invention is preferably in the range of about 0.1 to 5 mm when dried, and is about lzm to 1 mm (particularly 10 to 100 mm). m).
  • the “size when dried” of the hydrogel or polymer is an average value of a maximum diameter (maximum dimension) of the hydrogel or polymer (an average of values measured at least 10 or more). Value). More specifically, in the present invention, for example, the following size can be used as the “size when dried” corresponding to the shape of the above hydrogel or polymer.
  • Microbeads Particle size (average particle size)
  • Fibrous average length of each fibrous piece
  • Film shape, irregular shape Average value of the maximum dimension of each piece
  • the diameter of a “sphere” having a volume equal to the average value of the volume of each piece (an average value obtained by measuring at least 10 pieces) instead of the above “average value of the maximum value” May be used as the “size when dried” of the hydrogel or polymer.
  • the temperature control of the temperature-sensitive heating element of the present invention is based on the absorption and release characteristics of water depending on the temperature of the temperature-sensitive hydrogel, there is no restriction on the configuration / type of the heating section.
  • the member or composition has a conventionally known heat-generating property, it can be used in the present invention without any particular limitation.
  • a heat-generating member include a heat-generating member using electricity, a heat-generating member using a dry battery or a solar cell, a paper-like battery, and a chemical heating agent.
  • a chemical exothermic agent is preferably used in terms of good portability, low cost, and the like.
  • the “chemical exothermic agent” that can be used in the present invention refers to a compound or composition having a property of generating heat using a chemical reaction.
  • a chemical exothermic agent known ones can be used without any particular limitation as long as the function of the above-mentioned thermosensitive hydrogel is not substantially inhibited.
  • a heating element that generates heat by contact with air or oxygen, and a chemical heating agent utilizing the heat of oxidation of metal powder (iron powder, etc.) can be preferably used. is there.
  • composition of such a chemical exothermic agent a substance system that generates an exothermic reaction in the coexistence of air and water can be suitably used. Examples of such material systems are shown below.
  • iron powder reduced iron powder (iron powder); activated carbon, charcoal, fiber powder, Alumina, sily gel, perlite, vacuum, sodium chloride, potassium chloride, potassium iodide, potassium thiocyanate, calcium hydroxide, iron chloride, acetic acid, chloroacetic acid (reaction aid); water; high A composition in which a heat-generating material such as a water-absorbing resin (water retention agent) is appropriately blended and formulated may be used.
  • a heat-generating material such as a water-absorbing resin (water retention agent) is appropriately blended and formulated may be used.
  • a water retention agent may be further added to the substance system of such an embodiment.
  • other water retention agents are used.
  • thermosensitive gel of the present invention has a function as a water and a water retaining agent among them. If necessary, the thermosensitive hydrogel and a conventionally known water retaining agent may be used in combination.
  • the compounding amount of the thermosensitive hydrogel is preferably about 0.1 to 20 wt% of the entire chemical exothermic agent as a thermosensitive hydrogel-forming polymer, and more preferably about 1 to 10 wt% (particularly 3 to 10 wt%). (About 5 wt%). (Channeling agent)
  • the temperature-sensitive heating element suitably usable in the present invention includes a heating system (metal, water; activated carbon, salts and the like if necessary) which generates heat upon contact with air or oxygen, and a control system for sensing and controlling the temperature.
  • a heating system metal, water; activated carbon, salts and the like if necessary
  • a control system for sensing and controlling the temperature.
  • the heat-generating system and the hydrogel are homogenized and integrated), so that air is efficiently supplied to the heat-generating system.
  • Air is passed through the drogels (typically, agar-like or jelly-like), and the heat-generating system (particularly Preferably, there are pores or voids reaching the surface of the iron powder.
  • the hydrogel on the surface of the walls of such pores or voids releases or absorbs water depending on the temperature, and has the effect of narrowing or widening the channels of air or oxygen in the pores or voids.
  • the presence of such pores or voids is preferable in the temperature-sensitive heating element of the present invention.
  • a known agent can be used without any particular limitation.
  • the channeling agent include those having an irregular shape and a high porosity (for example, having a porosity of 20% or more), those having a large number of capillaries therein, and an open-cell structure. And the like. More specifically, examples thereof include expanded polystyrene powder, pulp, fiber powder, diatomaceous earth, perlite, and other filter aids.
  • This channeling agent is preferably used in a weight of 20% or less (more preferably, 15% or less, especially 10% or less) based on the total weight of (water + hide mouth gel).
  • thermo-sensitive hydrogel As the chemical exothermic agent, various salts may be used as a reaction aid, if necessary. Depending on the type and amount of the salt, the temperature dependency of the thermo-sensitive hydrogel may change. In other words, salts may exert an important function as a co-catalyst for air oxidation in an exothermic system, and in a temperature control system, it is necessary to change the equilibrium water absorption ratio and LCST in a thermosensitive hydrogel. It can be a factor.
  • the LCST behavior is based on hydrophobic interactions, as described above. That is, when ions (salting-out salts) tending to promote water structuring coexist, the LCST tends to decrease due to an increase in the hydrophobic interaction of the polymer as the concentration increases. Conversely, it tends to destroy water structures. When ON (salt-soluble salt) is present, the hydrophobic interaction of the polymer is weakened as the concentration increases, and the LCST tends to increase. In the case of salts of these intermediate properties, the LCST does not change regardless of the amount added.
  • thermosensitive hydrogel can be controlled by the type and amount of the salt used for the chemical exothermic agent.
  • salting out salts such as sodium chloride, potassium chloride, calcium chloride, potassium bromide, sodium sulfate, ammonium sulfate, etc.
  • the equilibrium water absorption ratio also tends to shift to the lower side.
  • lowering the salt concentration allows setting in a higher temperature range, while increasing the concentration allows setting in a lower temperature range. Since the salt concentration can be finely changed from 0% to saturation, it is possible to determine the set temperature arbitrarily and precisely by using such temperature control based on the salt concentration.
  • potassium thiocyanate is a salt-soluble salt, L C ST increases as its concentration increases. Therefore, potassium thiocyanate can be suitably used for temperature control on the high temperature side (for example, 55 ° C or higher).
  • potassium iodide which is a salt having the above intermediate properties
  • a relatively high temperature side for example, about 50 to 55 ° C.
  • the selection of the type and concentration of the salt in the present invention can be suitably used from the viewpoint of selecting the set temperature and the gradient of the equilibrium water absorption magnification line.
  • the temperature-sensitive heating element in view of the fact that the temperature-sensitive heating element is controlled at a constant temperature, water released from the hide port gel due to the rise in temperature moves freely in the channel forming the air flow path, Conversely, it is preferred that the liquid be freely moved by the decrease in temperature and absorbed by the hydrogel. It is preferable to use a surfactant from the viewpoint of facilitating free movement of water. Known surfactants that can be used for such purposes can be used without particular limitation. It is preferable that the surfactant is added in an amount of 2% or less (more preferably 1% or less, particularly 0.5% or less) to the water used for the temperature-sensitive heating element.
  • a surfactant is effective in suppressing the deviation from the set temperature that appears after the rise of the temperature in the heat-generating characteristics of the temperature-sensitive heating element, and in the form of a gentle hill that occurs near the end point in the latter half. It is also effective in suppressing deviation.
  • surfactants include, as anionic surfactants, Sandet LNM ⁇ Cedran type alkyl sulfate ester sodium, alkyl benzene sulfonate soda type from Sanyo Chemical Co., Ltd .; Toho Chemical Co., Ltd. And sodium dialkylsulfosuccinates such as air ports.
  • Nonionic surfactants include alkylphenol ethylene oxide adducts such as Sanyo Chemical's nonipol, etc., sanmorin 11, nonipol soft and cedran alkyl ether ethylene oxide adducts, and Kao Corporation ), Synthetic detergents such as “Attack”. These surfactants may be appropriately mixed or used in combination as needed.
  • thermosensitive exothermic agent of the present invention may be used, if necessary.
  • Such sparingly soluble salts account for 3% by weight of the water used for the heat-sensitive exothermic agent. Addition of the following (more preferably 1% or less, especially 0.5% or less) is effective in correcting a gentle hill-shaped deviation occurring near the end point in the latter half of the exothermic characteristic of the thermosensitive exothermic agent of the present invention.
  • the term "sparingly soluble salts" refers to a weight of 0.5 g or less (more preferably 0.1 g or less, especially 0.1 g or less) dissolved in 10 ° m1 of water at normal temperature (25 ° C). 0 1 g or less).
  • sparingly soluble salts for example, calcium carbonate, sulfated calcium sulfate, barium carbonate, barium sulfate, magnesium carbonate, manganese carbonate, etc. are preferably used alone or as a mixture of two or more as needed. It is possible.
  • thermosensitive hydrogel is extremely effective for controlling the temperature of the chemical exothermic agent.
  • thermosensitive hydrogel when the heat generated by the oxidation reaction of iron progresses and reaches a predetermined temperature, the reducing agent is released together with water from the thermosensitive hydrogel, and in addition to cooling with water, Suppression of iron oxidation by the reducing agent works to prevent the heating element from overheating.
  • the thermosensitive hydrogel when the temperature-sensitive hydrogel is cooled to a temperature lower than the predetermined temperature, the thermosensitive hydrogel absorbs the reducing agent together with the external water, so that the cooling and reduction reaction due to the evaporation of water are suppressed, and the temperature is excessively lowered. And prevent.
  • a known reducing agent can be used without any particular limitation as long as it has a function of inhibiting or suppressing the air oxidation reaction of iron.
  • a water-soluble reducing agent and a fat-soluble reducing agent can be used, but a water-soluble reducing agent is preferably used because it can be used as a uniform aqueous solution. Can be.
  • water-soluble reducing agent examples include ascorbic acid (salt), nitrous acid (salt), bisulfite (salt), hydrogen sulfide, thiourea, cysteine, cystamine, glutathione, and the like. It is not limited. (Bag-like member)
  • the heating element using the thermosensitive gel of the present invention since the heating element using the thermosensitive gel of the present invention has a temperature control function by itself, it is necessary to store the heating element in the “bag-shaped member” when the heating function is developed. There is no. However, from the viewpoint of easiness of handling, manufacturing and sales, or safety, it is preferable to arrange or house the heating element of the present invention in a “bag-like member” having air permeability.
  • an extensible bag-shaped member is used as the above-mentioned bag-shaped member as necessary. it can.
  • a material of the “stretchable bag-like member” a conventionally known material can be used without any particular limitation.
  • Examples of the material of the “stretchable bag-like member” include those used in commercially available stretchable patches such as urethane-based nonwoven fabric, polypropylene, and polyethylene.
  • the temperature-sensitive heat generating body of the present invention is adhered to, or brought into contact with or in close contact with, the affected part, so that a constant temperature is maintained even when the affected part is bent. Becomes possible.
  • thermal patches such as disposable body warmers, thermal shipping agents, and heat plus Yuichi have been used to relieve pain in joints such as arthritis and rheumatism, as well as inflexible parts such as indirect pain such as elbow pain and knee pain.
  • the above-described “stretchable bag-like member” is used in the above-described embodiment of the present invention. It is advantageous.
  • the temperature was controlled by adjusting the porous membrane of a storage bag such as a “disposable warmer”.
  • FIG. 1 An example of an embodiment using the above bag-shaped member is shown in a schematic cross-sectional view of FIG.
  • a heating element 1 using the thermosensitive hydrogel of the present invention is arranged or enclosed in a storage bag 2.
  • both ends of the storage bag 2 are sealed by known means such as heat sealing and an adhesive.
  • the storage bag 2 is preferably a bag-like member capable of restricting the amount of inflow of air.
  • a conventionally known material for example, a material obtained by forming a needle hole in a non-woven fabric in which polyethylene or the like is laminated as a sealant, a porous film, or the like can be used without particular limitation.
  • a bag-like member having one surface used as an air inflow surface and an adhesive layer laminated on the other surface is used, and a heating element using thermosensitive hydrogel is arranged inside the bag-like member. It is also possible to stick the pressure-sensitive adhesive layer side of the shaped member to the skin.
  • a known adhesive can be used without any particular limitation. More specifically, for example, a rubber-based, vinyl acetate-based, ethylene monoacetate-based, polyvinyl-based, acrylic-based, polyamide-based, or hot melt-based adhesive can be used as the adhesive.
  • rubber-based, acrylic-based, or hot-melt type is preferably used.
  • the thickness of the above adhesive layer is 10 to 500 zm, and more preferably 15 to 250 m is preferred.
  • the basic mechanism of the conventional heat generation control by limiting the ventilation rate is different from that of the heat generation control using the temperature-sensitive hydrogel, so that when these two are combined, they contribute synergistically.
  • the basic mechanism of the conventional heat generation control by limiting the ventilation rate is different from that of the heat generation control using the temperature-sensitive hydrogel, so that when these two are combined, they contribute synergistically.
  • the temperature-sensitive heating element of the present invention described above has a new function or utility based on a mechanism 'method completely different from that of a conventional heating element.
  • the first characteristic of the heating element of the present invention is that, unlike the conventional heating element, it is not essential to use a porous membrane together, that is, the heating temperature can be controlled well even in a mode in which no porous membrane is used. It is.
  • the temperature-sensitive heating element of the present invention can control the temperature even when used in a state of being completely open to the air.
  • a gas permeable membrane in the present invention, it is sufficient that the gas permeable membrane has sufficient gas permeability so that the powder does not dissipate, and the gas permeability and moisture permeability are not particularly limited.
  • the reason why the temperature control can be performed without the necessity of the gas permeable membrane is due to the fact that, in addition to the above-described formation of the “microscopic structure” that restricts the ventilation rate, According to the findings of the present invention, a minute capillary or a void exists in the thermosensitive hydrogel constituting the heating element, and air flows through the capillary or the void; and the capillary or the void.
  • the temperature of air is regulated by releasing or absorbing water depending on the temperature, and a constant temperature is maintained.
  • the thermosensitive mouth gel used in the present invention a thermosensitive hydrogel whose equilibrium water absorption capacity continuously decreases as the temperature rises.
  • a second feature of the temperature-sensitive heating element of the present invention is that the temperature deviation can be significantly reduced with respect to a set temperature as compared with a conventional heating element, that is, a substantially constant temperature is maintained. It can be held.
  • heating characteristic temperature curve which is a plot of the temperature after the start of heat generation with respect to time, after rising (rapid rise in temperature), followed by a temperature maintenance region (a temperature region near the set temperature). ) Since entry, the temperature gradually decreased, the temperature gradually increased, or both, and very few showed a constant value.
  • thermosensitive heating element of the present invention estimated by the present inventors is shown in the graphs of FIGS. 2A and 2B. ) Will be described. The following mechanism is based solely on the inventor's presumption, and therefore does not limit the scope of rights of the present invention in any way.
  • the X axis indicates temperature
  • the Y axis indicates the above-mentioned equilibrium water absorption capacity (W 2 —W,) /.
  • the weight ratio of water to dried hydrogel (hydrogel-forming polymer) is w at temperature t, this state is indicated by point P.
  • magnification line When the exotherm starts and the temperature rises, this point P moves parallel to the X-axis of the graph, and the point P t on the above-mentioned line indicating the equilibrium water absorption ratio of this polymer gel (hereinafter referred to as “magnification line”) Reach According to the knowledge of the present inventor, this magnification line is usually determined by the copolymer composition ratio of the polymer gel, the crosslink density, and the type and concentration of the salt used.
  • Tin Aw is the amount of released water, which serves to lower the temperature
  • Wam is the amount of absorbed water, which serves to increase the temperature. Since At is the control deviation of temperature,
  • Equation (1) above belongs to the concept of proportional control in control theory. Then, the operation output A w operates until ⁇ t approaches 0, so that the temperature converges until it becomes constant at the set value. Such a phenomenon is a temperature control that has not been used for any conventional heating element, as well as when a porous film is used.
  • a third feature of the temperature-sensitive heating element of the present invention is that the set temperature can be set freely and precisely.
  • the above-mentioned “magnification line” is determined by the copolymer composition ratio of the polymer and the degree of crosslinking, but the temperature can be set in a relatively high, medium or relatively low temperature region by further selecting the kind of the salt.
  • the salt concentration In other words, when sodium chloride is used, the temperature is set high when the concentration is low, and the temperature is low when the concentration of sodium chloride is high. Since the concentration of sodium chloride can be finely changed from 0% to saturation, it is possible to finely select the set temperature.
  • the set temperature of the heating element can be changed by the method of manufacturing the temperature-sensitive heating element. Such temperature adjustment using the salt concentration could not be imagined in a heating element using a conventional porous membrane.
  • the fourth feature of the temperature-sensitive heating element of the present invention is that the comprehensive functions including the first to third features can be manufactured at extremely low cost and more economically than before.
  • it is not essential to use an expensive special porous membrane as used in a conventional heating element, and therefore, in the case where a porous membrane is used as necessary in the present invention.
  • a general-purpose inexpensive porous membrane can be used (since no air flow control is required by the membrane).
  • the gel was transferred to a household mixer and ground with 400 mL of distilled water. Then, 350 mL of ethanol was added, the mixture was heated to 60 ° C, and centrifuged (1, 500 rpm, 5 minutes) to recover the gel. After vacuum drying, the mixture was pulverized again by a mixer to obtain 22 g of a thermosensitive hydrogel-forming polymer.
  • thermosensitive hydrogel-forming polymer 0.30 g of the dried thermosensitive hydrogel-forming polymer is immersed in a 5 wt% saline solution at a predetermined temperature (various temperatures such as the following) for 48 hours to swell, and then centrifuged at the predetermined temperature to generate excess water. After removing the water, the thermosensitive hydrogel was weighed, and the equilibrium water absorption capacity was determined by (Equation 1). The result was 30 times (25 ° 0, 22 times (35 ° C), 11 times (25 ° C). 40 ° C), 6 times (42 ° C), 3 times (44 ° C), It was three times (50 ° C).
  • thermosensitive hydrogel-forming polymer synthesized in Example 1 in a glass beaker 0.15 g of dry thermosensitive hydrogel-forming polymer synthesized in Example 1 in a glass beaker (diameter 3.0 cm, height 4.4 cm), activated carbon (powder, manufactured by Wako Pure Chemical Industries) 0.3 g was added, 3.0 g of 5 wt% saline was added, and the mixture was stirred well at room temperature. Next, add 3.0 g of iron powder (manufactured by Wako Pure Chemical Industries, Ltd.), stir well with a spoonful, place on a styrofoam plate (size: 20 x 30 cm, thickness: 20 mm), and cover the top of the beaker with filter paper.
  • thermocouple thermometer (trade name: 2455 type, manufactured by Yokogawa Electric Corporation) (the exothermic agent was stirred every 30 minutes).
  • a bead type probe (type 2459-07, manufactured by Yokogawa Electric Corporation) of the thermocouple thermometer was placed between the bottom of the beaker and the styrene foam plate.
  • Example 4 An experiment was conducted in the same manner as in Example 2 except that 0.3 g of ascorbic acid (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in the saline solution of Example 2. The maximum temperature was 44 minutes after mixing the iron powder. ° C, and the duration of heat generation at 40 ° C or more was 5 hours or more.
  • ascorbic acid manufactured by Wako Pure Chemical Industries, Ltd.
  • Example 2 Dry thermosensitive hydrogel-forming polymer synthesized in Example 1 in a glass beaker (diameter: 3.0 cm, height: 4.4 cm) 0.50 g, activated carbon (powder, manufactured by Wako Pure Chemical Industries) A mixture of 0.30 g and 3.0 g of iron powder (manufactured by Wako Pure Chemical Industries) was thoroughly stirred with a spoonful of medicine. Then, 3.0 g of 5 wt% saline was added to this, Further, the mixture was stirred well at room temperature.
  • thermocouple thermometer Yokogawa Electric Co., Ltd.
  • Product name: Model 2455 the bead-type probe of the thermocouple thermometer (Yokogawa Electric Corp., 2459-07 type) was placed between the bottom of the beaker and the styrene foam plate (at room temperature of 27 ° C, Humidity 64%).
  • Example 2 The same experiment as in Example 2 was performed, except that 0.15 g of a commercially available superabsorbent resin (manufactured by Mitsubishi Chemical Corporation, Diajet) was used instead of the thermosensitive hydrogel-forming polymer of Example 2. However, the maximum temperature reached 68 ° C in 20 minutes after mixing the iron powder, and the heat generation duration over 40 ° C was 90 minutes.
  • a commercially available superabsorbent resin manufactured by Mitsubishi Chemical Corporation, Diajet
  • a glass beaker (diameter: 3.0 cm, height: 4.4 cm) with Loca help (filtration aid, powder, Mitsui Kinzoku Co., product number: B 409) 0.5 g, activated carbon (powder powder, Wako Pure Chemical Industries, Ltd.) 0.3 g of iron powder (3.0 g) and iron powder (3.0 g) were stirred well at room temperature. 3.0 g of 3 w / w% saline was added thereto, and mixed well with a medicine spoon. Next, to the mixture thus obtained was added 0.5 g of the dry thermosensitive mouth-opening gel-forming polymer synthesized in Example 1, and the mixture was immediately stirred with a spoonful for 2 minutes. The exothermic composition in the inside was lightly pressed with a spoonful of scoop and adjusted so that its surface was almost flat. (In this embodiment and thereafter, the heating element was agitated during the temperature measurement. Absent) .
  • thermocouple thermometer Kika Eve ST50, manufactured by Rika Denki Co., Ltd.
  • Example 5 An exothermic test was performed and the temperature was recorded in the same manner as in Example 5 except that the concentration (3 w / w%) of the saline used in Example 5 was changed to 5 w / w%.
  • Example 5 An exothermic test was performed in the same manner as in Example 5 except that the concentration of the saline solution (3 w / w%) used in Example 5 was changed to 7 w / w%, and the temperature was recorded.
  • Example 6 (curve in FIG. 3 B), drops along the line downward sloping at the intersection P B with 5% of the equilibrium absorption capacity lines, it becomes constant at a magnification 3.
  • Theoretical value of the P B is 4 2.
  • a 1 ° C the actual experimental values (Example 6) 4 1. 0 ⁇ 2 Good agreement with ° c.
  • Example 7 curve C in FIG. 3
  • Pc equilibrium water absorption of 7%
  • theoretical value of Pc 37.5 ° C
  • Experimental value (Example 7) 38.0 ⁇ 2 ° C, which is in good agreement.
  • the temperature-sensitive heating element of the present invention can satisfactorily simulate the actual temperature control based on the equilibrium water absorption magnification graph (FIG. 4).
  • N, N, ⁇ ', N'-tetramethylethylenediamine (1.3 mL) was added for polymerization. It gelled about 10 minutes after the start of the reaction, but was left at room temperature for 4 hours. The gel was transferred to a household mixer and crushed by adding 4 L of distilled water. Then, 3.5 L of ethanol was added, the mixture was heated to 60 ° C, and centrifuged (1, 500 rpm, 5 minutes) to collect a gel.
  • thermosensitive hydrogel-forming polymer After vacuum drying, the mixture was again ground by a mixer to obtain about 220 g of a thermosensitive hydrogel-forming polymer. 0.30 g of the dried thermosensitive hydrogel-forming polymer is immersed in water at a predetermined temperature ("various temperatures" shown below) for 48 hours to swell, and then centrifuged at the predetermined temperature to remove excess water. After removal of water, the weight of the thermo-sensitive hydrogel was measured and the equilibrium water absorption capacity was determined by (Equation 1). The results were 30 times (25 ° C), 22 times (35 ° C) and 11 times (35 ° C). 40 ° C), 6 times (42 ° C), 3 times (44 ° C), and 3 times (50 ° C).
  • Example 5 The temperature-sensitive hydrogel-forming polymer used in Example 5 was replaced with An exothermic test was performed in the same manner as in Example 5 except that the thermosensitive hydrogel-forming polymer-2 synthesized in Example 8 was used and 2.5 g of 5 w / w% saline was used. The exothermic temperature was recorded.
  • Example 9 An exothermic test was performed in the same manner as in Example 9 except that 3.0 g of the 5 w / w% saline used in Example 9 was used, and the exothermic temperature was recorded.
  • Example 9 An exothermic test was performed in the same manner as in Example 9 except that 3.5 g of the 5 w / w% saline used in Example 9 was used, and the exothermic temperature was recorded.
  • Curve F (Example 11) has a maximum and minimum temperature between 36.3 ⁇ 1.75 ° C after rising and entering the attenuation line, and curve E (Example 10). was 40.8 ⁇ 2.3 ° C. The exothermic temperature increased when the saline / gel weight ratio was reduced by a factor of seven or six.
  • Curve D (Example 9) shows a 43 ° C To 54.5 ° C. According to the findings of the present inventor, the cause of this is that, using this polymer, 5% saline, which is five times as large as the gel, lacks the saline solution, and the specified temperature control efficiency is poor. It is estimated to be.
  • thermosensitive hydrogel-forming polymer 3 (Synthesis of thermosensitive hydrogel-forming polymer 3)
  • thermosensitive hydrogel-forming polymer a thermosensitive hydrogel-forming polymer.
  • thermosensitive hydrogel-forming polymer 0.30 g of the dried thermosensitive hydrogel-forming polymer is immersed in 2 wt% saline at a predetermined temperature (various temperatures such as those described below) for 48 hours to swell, and then centrifuged at the predetermined temperature to generate excess water. After the water was removed, the weight of the thermo-sensitive hydrogel was measured and the equilibrium water absorption capacity was calculated by (Equation 1). The equilibrium water absorption capacity was 30 times (25 ° C), 22 times (35 ° 0, 11 times (40 ° 0, 6 times (42 ° C), 3 times (44 ° C) and 3 times (50 ° C).
  • thermosensitive hydrogel-forming polymer-1 used in Example 5
  • the temperature-sensitive hydrogel-forming polymer-3 synthesized in Example 12 was used.
  • An exothermic test was performed in the same manner as in Example 5 except that an aqueous w / w% calcium chloride solution was used, and the exothermic temperature was recorded.
  • the exothermic temperature is shown as “Curve G” in the graph of FIG. As shown in this “curve G”, the temperature reached 51 ° C in 15 minutes after adjusting for heat generation, and reached a maximum of 55 ° C in 2 hours and 30 minutes. 3 8.
  • the exothermic duration at temperatures above C was 4 hours and 50 minutes.
  • the temperature reached 47.5 ° C. in 15 minutes after adjusting the exothermic composition and reached a maximum of 49 ° C. in 2 hours and 45 minutes.
  • the heat generation duration at a temperature of 38 ° C. or more was 5 hours and 15 minutes.
  • Example 6 instead of the 5 w / w% saline solution used in Example 6, a commercially available synthetic detergent (manufactured by Kao Corporation, trade name: Attack: surfactant, linear alkylbenzenesulfonic acid soda polyoxyethylene alkyl ether) ⁇ Exothermic test was performed and the exothermic temperature was recorded in the same manner as in Example 5, except that 5 w / w% saline containing 1% containing sodium alkyl sulfate was used. The obtained exothermic temperature is shown as “Curve I” in the graph of FIG.
  • “Curve I” (Example 15) in the graph of FIG. 7 shows the effect of the addition of the surfactant.
  • this “Curve I” is compared with “Curve B” (Example 5)
  • the peak immediately after the rise of the B line disappears, and the synthetic detergent attack was added. The effect of addition has appeared.
  • Example 6 instead of the 5 w / w% saline used in Example 6, a commercially available surfactant, Sanmorin OT-70 (sodium dioctylsulfosuccinate), manufactured by Sanyo Chemical Co., Ltd. containing 1% was used.
  • An exothermic test was performed in the same manner as in Example 6 except that w% saline was used, and the exothermic temperature was recorded. The obtained exothermic temperature is shown as “Curve J” in the graph of FIG. Comparing this “curve J” with the above-mentioned “curve B” (Example 5), it shows the effect of flattening the hill-shaped high-temperature part in the latter half of “curve B”. ° C.
  • Example 6 The procedure was performed except that a 5% w / w% saline solution containing 1% of a synthetic detergent, 1% attack and 1% of sodium dioctylsulfosuccinate was used instead of the 5% w / w% saline solution used in Example 6.
  • An exothermic test was performed in the same manner as in Example 6, and the exothermic temperature was recorded. The obtained temperature is shown as “Curve P” in the graph of FIG. Comparing this “Curve P” with “Curve B” in Example 6, both the peak immediately after the rise of “Curve B” and the hill-shaped high-temperature part in the latter half disappear, and the 41.0 ⁇ 2 of “Curve B” disappears. 0 ° C could be controlled to 40.0 ⁇ 0.5 ° C.
  • a commercially available mixer, Matsushita Electric, National Mixer MX-X51- W-type cutlery attached to W is remodeled into Mitsui Kinzoku LokaHelp (filtration aid) 2.5, Activated carbon (manufactured by Wako Pure Chemical Industries) 1.5 g and iron powder 15 g were charged, and the mixture was thoroughly mixed by rotating a stirrer. 15 g of a 3 w / w% saline solution was added thereto to prepare a slurry. Next, while rotating the stirrer of the mixer at a high speed, 1.5 g of the dry thermosensitive gel-forming polymer 1 of the temperature-sensitive mouth synthesized in Example 1 was added, followed by stirring for 1 minute. A granular heating element composition was prepared.
  • Example 5 As in Example 5, 7.5 g of the heating element composition obtained above was placed in a glass beaker, and a heat generation test was performed. The obtained exothermic temperature is shown as “Curve M” in the graph of FIG.
  • Example 16 An exothermic test was performed in the same manner as in Example 16 except that 5 w / w% saline was used instead of the 3 w / w% saline used in Example 16. The obtained exothermic temperature is shown as “Curve N” in the graph of FIG.
  • Example 16 An exothermic test was performed in the same manner as in Example 16 except that 7 w / w% saline was used instead of the 3 w / w% saline used in Example 16. The obtained exothermic temperature is shown as “Curve ⁇ ” in the graph of FIG.
  • the “Curve M” was controlled at 45 ⁇ 0.5 ° C, and the accuracy was significantly better than that of “Curve A” at 46 ⁇ 2 ° C.
  • “Curve N” was controlled at 41 ⁇ 0.5 ° C, and the accuracy was significantly improved compared to “Curve B” at 41 ⁇ 2 ° C.
  • the accuracy of “Curve 0” was controlled at 38.5 ⁇ 0.5 ° C, and the accuracy was remarkably improved compared to 38 ⁇ 2 ° C of “Curve C”.
  • thermosensitive heat-generating material containing a thermosensitive hydrogel comprising at least water and a polymer having a mouth-opening gel-forming property and having a reduced equilibrium water absorption capacity with increasing temperature.
  • a body is provided.
  • the temperature-sensitive heating element of the present invention having the above configuration is characterized by including, as a heating member, a temperature-sensitive hydrogel whose equilibrium water absorption capacity decreases as the temperature rises, and when the temperature rises above a predetermined temperature. Water is released from the thermo-sensitive hydrogel to cool the heating element and prevent the heating element from being excessively heated. On the other hand, when cooled to a temperature lower than the predetermined temperature, the thermosensitive hydrogel absorbs external water, so that cooling due to evaporation of water is suppressed, and the temperature is prevented from excessively lowering. As described above, the temperature-sensitive heating element of the present invention senses the temperature itself and controls the heating temperature more precisely, so that the danger of low-temperature burn and the like can be avoided.
  • thermosensitive hydrogel comprising at least water and a polymer having a gel-forming property at a mouth, and having a continuously decreasing equilibrium water absorption capacity in proportion to an increase in temperature.
  • a heat-sensitive heating element is provided.
  • the temperature-sensitive heating element of the present invention having the above-described configuration, when the temperature becomes higher than a predetermined temperature, water is released from the temperature-sensitive hydrogel in proportion to a deviation from the predetermined temperature, and this water is discharged. It narrows the narrow tubes or voids in the gel at the mouth of the air, through which air flows, to reduce the flow of air, suppress the oxidation reaction, and reduce the temperature. On the other hand, when the temperature decreases, the gel at the mouth absorbs water, widens the channel of the air channel, activates the oxidation reaction, and turns the temperature to rise and the temperature to drop excessively. To prevent.
  • the heating element itself senses the temperature, and releases and absorbs water as an operation output in proportion to a deviation from a predetermined temperature, and
  • This is a completely new type of heating element that maintains the specified temperature more precisely by repeating temperature control based on proportional control by repeatedly suppressing the rise and fall of the temperature. Its application area is not only capable of avoiding low-temperature burns on the human body, which is a problem, but also enables strict temperature control at low cost and local warming of the human body, opening up a new field for hyperthermia. I made it.

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Abstract

L'invention concerne un élément chauffant thermosensible caractérisé par le fait qu'il contient un hydrogel thermosensible comprenant de l'eau et un polymère de formation d'hydrogel et dont le coefficient d'absorption d'eau à l'équilibre diminue en cas de hausse de température.
PCT/JP1998/002889 1997-06-30 1998-06-26 Element chauffant thermosensible WO1999000078A1 (fr)

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AU79347/98A AU7934798A (en) 1997-06-30 1998-06-26 Thermosensitive heating element
JP50544499A JP3978474B2 (ja) 1998-06-26 1998-06-26 感温性発熱体

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JP9/174226 1997-06-30
JP17422697A JP2004089211A (ja) 1997-06-30 1997-06-30 感温性発熱体

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JP2005508069A (ja) * 2001-10-31 2005-03-24 モトローラ・インコーポレイテッド 可変孔隙率ガス拡散材料を用いた燃料電池および稼働方法
JP2009082281A (ja) * 2007-09-28 2009-04-23 Japan Pionics Co Ltd 発熱袋
JP2018046001A (ja) * 2011-08-19 2018-03-22 国立大学法人九州大学 イオン濃度勾配発生システム、装置、方法、及び、温度応答性電解質材料
KR20200115464A (ko) 2018-02-05 2020-10-07 페릭가부시키가이샤 온도 제어제, 발열 조성물 및 이를 사용하는 온열 장치

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US20100028758A1 (en) * 2008-08-04 2010-02-04 Eaves Stephen S Suppression of battery thermal runaway

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JPH0251534U (fr) * 1988-10-07 1990-04-11

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JPH0251534U (fr) * 1988-10-07 1990-04-11

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005508069A (ja) * 2001-10-31 2005-03-24 モトローラ・インコーポレイテッド 可変孔隙率ガス拡散材料を用いた燃料電池および稼働方法
JP2009082281A (ja) * 2007-09-28 2009-04-23 Japan Pionics Co Ltd 発熱袋
JP2018046001A (ja) * 2011-08-19 2018-03-22 国立大学法人九州大学 イオン濃度勾配発生システム、装置、方法、及び、温度応答性電解質材料
US10137409B2 (en) 2011-08-19 2018-11-27 Kyushu University, National University Corporation System, device and method for generating ion concentration gradient, and temperature-responsive electrolyte material
US10300432B2 (en) 2011-08-19 2019-05-28 Kyushu University, National University Corporation System, device, and method for producing ion concentration gradient, and temperature-responsive electrolyte material
US10695714B2 (en) 2011-08-19 2020-06-30 Kyushu University, National University Corporation System, device, and method for producing ion concentration gradient, and temperature-responsive electrolyte material
JP2022140462A (ja) * 2011-08-19 2022-09-26 国立大学法人九州大学 温度応答性電解質材料、温度応答性電解質フィルム、膜、並びにイオン濃度勾配を生じさせる装置及び方法
KR20200115464A (ko) 2018-02-05 2020-10-07 페릭가부시키가이샤 온도 제어제, 발열 조성물 및 이를 사용하는 온열 장치
US12042427B2 (en) 2018-02-05 2024-07-23 Ferric Inc. Temperature control agent, and heat-generating composition and warming device each using same

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