JP2021013450A - Heating element - Google Patents

Abstract

To provide a heating element capable of decreasing maximum temperature of a heating surface and suppressing local high temperature rising.SOLUTION: A heating element 1 includes a bag body 2 formed into a bag shape with a front side sheet part 21 and a reverse side sheet part, and a heating material 4 encapsulated into the bag body. The bag body includes a joint part 3 where the front side sheet part and the reverse side sheet part are joined. The joint part includes a marginal part 31 formed along at least part of an outer periphery of the bag body and a projection part 32 that projects from the marginal part to a heating material side.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heating element.

Patent Document 1 discloses a conventional heating element. The heating element described in Patent Document 1 includes a heat-generating composition (heating material) that generates heat when it comes into contact with air, and a storage bag (bag body) that stores the heat-generating composition. The storage bag is formed in a bag shape by stacking two sheet materials and sealing the outer peripheral edge portion.

JP-A-2018-376

By the way, in the heating element described in Patent Document 1, when the temperature distribution on the heating surface is viewed, the temperature in the central portion tends to be relatively high when viewed from the front, but the temperature rises locally on the heating surface. Is less desirable. Various measures have been taken for the local high temperature rise on the heat generating surface of the heating element, and better measures are desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heating element capable of lowering the maximum temperature of the heat generating surface and suppressing a locally high temperature rise.

The heating element of one aspect according to the present invention includes a bag body formed in a bag shape by the front side sheet portion and the back side sheet portion, and a heat generating material enclosed in the bag body. The bag body has a joint portion in which the front side sheet portion and the back side sheet portion are joined. The joint portion includes an edge portion formed along at least a part of the outer periphery of the bag body, and a protruding portion protruding from the edge portion toward the heat generating material side.

Further, in the heating element, the protruding dimension of the protruding portion is 15% or more with respect to the dimension between the edge portion at the position corresponding to the protruding portion and the portion facing the protruding portion in the direction in which the protruding portion protrudes. It is preferably 35% or less.

Further, in the heating element, the dimension between the protruding portion and the portion facing the protruding portion in the direction in which the protruding portion protrudes is relative to the inner dimension of the bag body at a position corresponding to the protruding portion. It is preferably 30% or more and 70% or less.

Further, it is preferable that the heating element includes a plurality of protruding portions, and the protruding directions of the plurality of protruding portions are in a straight line.

Further, the heating element preferably has a recess formed at a portion corresponding to the protruding portion on the outer edge of the bag body.

Further, in the heating element, the bag body is formed in a rectangular shape in a front view having a width and a length, and the edge portion includes a portion formed along the length direction of the bag body, and the protruding portion. Is preferably formed in the central portion of the bag body in the length direction.

The heating element of the above aspect according to the present invention has an advantage that the maximum temperature of the heat generating surface can be lowered and a locally high temperature rise can be suppressed.

FIG. 1 is a front view of a heating element according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a front view of the heating element of the modified example 1. FIG. 4 is a front view of the heating element of the modified example 2-1. FIG. 5A is a front view of the heating element of the modified example 3-1. FIG. 5B is a front view of the heating element of the modified example 3-2. FIG. 6 is a front view of the heating element of the modified example 4. FIG. 7A is an enlarged view of a protruding portion of the heating element according to the modified example 5-1. FIG. 7B is an enlarged view of a protruding portion of the heating element according to the modified example 5-2. FIG. 7C is an enlarged view of a protruding portion of the heating element according to the modified example 5-3. FIG. 7D is an enlarged view of a protruding portion of the heating element according to the modified example 5-4. FIG. 7 (E) is an enlarged view of a protruding portion of the heating element according to the modified example 5-5. FIG. 8A is a front view of the heating element according to the first embodiment. FIG. 8B is a front view of the heating element according to the second embodiment. FIG. 8C is a front view of the heating element according to the third embodiment. FIG. 8D is a front view of the heating element according to the comparative example. FIG. 9 is a diagram showing the temperature distribution according to the result 1. FIG. 10 is a diagram showing the temperature distribution according to the result 2. FIG. 11 is a graph showing the temperature distribution according to the result 1. FIG. 12 is a graph showing the temperature distribution according to the result 2.

(1) Embodiment (1.1) Outline The heating element 1 according to the present embodiment can partially give a thermal effect to the body. As shown in FIGS. 1 and 2, the heating element 1 according to the present embodiment includes a bag-shaped bag body 2 and a heat-generating material 4 enclosed in the bag body 2.

The bag body 2 is formed in a bag shape by the front side sheet portion 21 and the back side sheet portion 22, and has a joint portion 3 at least in a part thereof. The joint portion 3 is a portion where the front side sheet portion 21 and the back side sheet portion 22 are joined. The joint portion 3 according to the present embodiment includes an edge portion 31 and a protruding portion 32.

As shown in FIG. 1, the edge portion 31 is formed along at least a part of the outer circumference of the bag body 2 (in the present embodiment, the total length of the outer circumference of the bag body 2). The protruding portion 32 protrudes from the edge portion 31 toward the heat generating material 4.

In the heating element 1 according to the present embodiment, the maximum temperature can be lowered while keeping the area of the high temperature region equal to or higher than that of the heating element having no protruding portion 32. Therefore, in the heating element 1 according to the present embodiment, the maximum temperature of the heat generating surface can be lowered, and a locally high temperature rise can be suppressed.

The "high temperature range" as used in the present disclosure means a temperature range of (maximum temperature −5 ° C.) or higher and lower than the maximum temperature in the temperature range of the heat generating surface.

(1.2) Details Hereinafter, the heating element 1 according to the present embodiment will be described in detail. The heating element 1 according to the present embodiment is suitably used for heating the waist or back. The heating element 1 according to the present embodiment is a heating element that utilizes the heat of reaction generated when an oxidation reaction occurs as a heat source, and is, for example, a disposable body warmer. The heating element 1 is housed in, for example, an airtight outer bag (not shown) that does not allow air to pass through before use.

The heating element 1 according to this embodiment has a large size. The term "large format" as used in the present disclosure means that when the heat generating surface is substantially rectangular when viewed from the front, the width dimension is 90 mm or more and the length dimension is 120 mm or more, and the heat generating surface is substantially rectangular. When the shape is other than the shape, it means that the area of the heat generating surface is 10800 mm ² or more. In the heating element 1 according to the present embodiment, the heating surface has a substantially rectangular shape, the width dimension is 116 mm, and the length dimension is 181 mm (the dimension of the longest part; the shortest part is 174 mm). In the present disclosure, "width" means a side shorter than "length".

Further, the "heating surface" referred to in the present disclosure means a portion of the surface of the bag body 2 surrounded by the edge portion 31 in the bag body 2. In the heating element 1 according to the present embodiment, each of the front side sheet portion 21 and the back side sheet portion 22 has a heating surface, and the front view and the rear view of the heating element 1 are directions in which the heating surface is viewed from the front. Is.

The heating element 1 may be of a normal size and is not limited to a large size. In addition to the waist or back, the heating element 1 can be held by the user and attached to or attached to any part of the body such as the limbs, abdomen, soles, shoulders, and buttocks. It may be used by wrapping it around the body.

(1.2.1) Heat-generating material The heat-generating material 4 is a material that can generate heat, and in the present embodiment, it is a powdery material that generates heat when it comes into contact with air. The heat generating material 4 is enclosed in the bag body 2.

The heat generating material 4 includes, for example, an oxidizing metal, activated carbon, carbon black, a water retaining agent, a metal salt (for example, salt) and water. The metal to be oxidized is a metal that emits heat of oxidation reaction, and examples thereof include one or more powders or fibers selected from iron, aluminum, zinc, manganese, magnesium and calcium, and among them, handleability. Iron powder is preferable from the viewpoint of safety, manufacturing cost, storage stability and stability. Examples of the iron powder include one or more selected from reduced iron powder and atomized iron powder. Examples of the water retention agent include wood powder, vermiculite, diatomaceous earth, pearlite, silica gel, alumina, and a water-absorbent resin. As the heat generating material 4, the composition used in the conventional disposable body warmer may be used as it is, and is not particularly limited.

As the heat generating material 4, a material other than a material that generates heat by contact with air may be used. As the heat generating material 4, for example, a material that generates heat when irradiated with microwaves in a microwave oven or the like (for example, ceramic powder such as ferrite, red beans, etc.) may be used.

(1.2.2) Bag body The bag body 2 has a storage space inside for accommodating the heat generating material 4. As shown in FIG. 2, the bag body 2 according to the present embodiment is formed flat and includes a front side sheet portion 21 and a back side sheet portion 22. A storage space is formed inside the bag body 2 by joining the front side sheet portion 21 and the back side sheet portion 22 by the joining portion 3.

As shown in FIG. 1, the bag body 2 according to the present embodiment is formed in a substantially rectangular shape in front view having a width and a length. However, the bag body 2 may be formed into, for example, a square shape in front view, a triangle shape in front view, a polygonal shape in front view of a pentagon or more, a perfect circle shape in front view, an ellipse shape in front view, and the shape is not limited. ..

(1.2.2.1) Front-side sheet portion The front-side sheet portion 21 is a sheet-shaped portion that forms one surface of the bag body 2. As shown in FIG. 2, the front side sheet portion 21 according to the present embodiment is composed of one sheet material. The front side sheet portion 21 according to the present embodiment has flexibility. As a result, the user can knead and loosen the heating element 1 by hand or fit it along the body.

It is preferable that a resin film is used for the front side sheet portion 21 according to the present embodiment from the viewpoint of strength, durability against heat generation of the heat generating material 4, and the like. As the resin used for the resin film, a thermoplastic resin is preferable. Examples of the thermoplastic resin include polyethylene, polypropylene, polyester, polyamide, polyurethane, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polycarbonate, ethylene-vinyl acetate copolymer and the like. These resins may be used alone or in combination of two or more.

Further, from the viewpoint of improving the feel of the heating element 1, it is preferable that the front side sheet portion 21 is provided with a woven cloth or a non-woven fabric on the outside of the resin film.

Examples of fiber materials for woven fabrics or non-woven fabrics include natural fibers such as cotton, linen, silk and paper, semi-synthetic fibers such as rayon and acetate, nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, polyvinyl chloride and poly. Examples thereof include synthetic fibers such as butylene terephthalate and mixed fibers of these fibers. Among these, as the fiber material, nylon, polyester, and polypropylene are preferable, and nylon and polyester are more preferable, from the viewpoint of improving the feel on the skin. These fiber materials may be used alone or in combination of two or more. The basis weight of the woven fabric or the non-woven fabric is not particularly limited as long as it can prevent the heat generating material 4 from leaking to the outside of the bag body 2, but as an example, 20 g / m ² or more and 70 g / m ² or less is exemplified.

However, the front side sheet portion 21 does not have to be a laminate of a resin film and a woven fabric or a non-woven fabric, and may be composed of a single resin film or a single woven fabric or non-woven fabric. Good.

The front side sheet portion 21 according to the present embodiment has breathability. In the front side sheet portion 21 according to the present embodiment, the front side sheet portion 21 has a plurality of holes because the resin film is a porous resin film or a resin film having a plurality of holes (not shown) formed therein. .. Therefore, the front side sheet portion 21 can ventilate the inside and outside of the bag body 2 through the plurality of holes. The plurality of holes may be formed evenly over the entire surface of the front side sheet portion 21, or may be formed densely in a part thereof. Further, the diameter of each hole may be a size that can suppress the heat generating material 4 from leaking through the hole, and as an example, 0.1 μm or more and 30 μm or less is exemplified. Further, the shape and quantity of the holes are not particularly limited. Since the sensible temperature of the heating element 1 changes according to the air volume of the bag body 2, the size, shape and quantity of the holes take into consideration the sensible temperature of the heating element 1 and the degree of suppression of leakage of the heating material 4. Then, it is set appropriately.

When the non-woven fabric is used alone as the front sheet portion 21, a plurality of holes may not be formed.

(1.2.2.2) Back side sheet portion The back side sheet portion 22 is a sheet-shaped portion of the bag body 2 that forms a surface opposite to the front side sheet portion 21. The back side sheet portion 22 according to the present embodiment is made of one sheet material. The back side sheet portion 22 according to the present embodiment has flexibility like the front side sheet portion 21.

As with the front sheet portion 21, a resin film is preferably used for the back sheet portion 22. However, the back side sheet portion 22 does not have to have the same structure and the same material as the front side sheet portion 21. The back side sheet portion 22 is preferably composed of a laminate of a resin film and a woven fabric or a non-woven fabric as in the front side sheet portion 21, but is not limited to this and is composed of a single resin film. It may be composed of a single woven fabric or a non-woven fabric.

The back side sheet portion 22 according to the present embodiment has breathability. Similar to the front side sheet portion 21, the back side sheet portion 22 according to the present embodiment is a back side sheet portion because the resin film is a porous resin film or a resin film having a plurality of holes (not shown) formed therein. 22 has a plurality of holes. However, the back side sheet portion 22 does not necessarily have to be breathable, and may be non-breathable.

The thickness of each of the front side sheet portion 21 and the back side sheet portion 22 is not particularly limited, but is preferably 0.1 mm or more and 2.0 mm or less, for example. This makes it possible to make the heating element 1 soft and easy to fit in the hand, while ensuring a certain strength.

(1.2.2.3) Joint portion The joint portion 3 is a portion where the front side sheet portion 21 and the back side sheet portion 22 are joined. The joint portion 3 according to the present embodiment is configured by welding (heat sealing) a part of the front side sheet portion 21 and a part of the back side sheet portion 22. However, the joint portion 3 does not have to be welded, and may be realized by, for example, bonding, suturing, crimping, or the like, or may be realized by a combination thereof. As shown in FIG. 1, the joint portion 3 includes an edge portion 31 and a plurality of (here, two) projecting portions 32.

The edge portion 31 is a portion of the joint portion 3 formed along the outer circumference of the bag body 2. The edge portion 31 according to the present embodiment is continuous over the entire outer circumference of the bag body 2. The width dimension of the edge portion 31 is not particularly limited, but is preferably 1 mm or more and 10 mm or less, and more preferably 3 mm or more and 7 mm or less. The edge portion 31 according to the present embodiment is formed to have substantially the same width dimension over the entire length.

The edge portion 31 according to the present embodiment includes a pair of long side portions 311 formed along the length direction, a pair of short side portions 312 formed along the width direction, and four corner portions 313. To be equipped. In this embodiment, the pair of long side portions 311 are formed in a substantially linear shape and are parallel to each other. In the present embodiment, the pair of short side portions 312 are curved so as to bulge outward in the length direction, but may be formed in a straight line. Each corner portion 313 connects the end of one long side portion 311 and the end of one short side portion 312. The corner portion 313 according to the present embodiment is formed in a rounded corner shape, but may be formed in a C chamfered shape, an obtuse angle shape, an acute angle shape, or the like, for example.

The protruding portion 32 is a portion of the joint portion 3 that protrudes from the edge portion 31 toward the heat generating material 4. In the heating element 1 according to the present embodiment, the protruding portion 32 protrudes from the edge portion 31 to lower the maximum temperature of the heat generating surface and suppress a locally high temperature rise. Further, according to the protruding portion 32, the heat generating material 4 is less likely to move in the length direction inside the bag body 2 and is less likely to be biased in the length direction.

The protruding portion 32 according to the present embodiment extends along the width direction of the bag body 2. In the present embodiment, the width dimension H1 of the protruding portion 32 is substantially the same as the width dimension of the edge portion 31.

The protruding dimension of the protruding portion 32 (hereinafter referred to as the protruding dimension L1) is preferably set as follows from the viewpoint of lowering the maximum temperature of the heat generating surface and suppressing a locally high temperature rise. That is, the protrusion dimension L1 of the protrusion 32 is preferably 5% or more, more preferably 10% or more, with respect to the inner dimension D2 of the bag body 2 at the position corresponding to the protrusion 32 in the direction in which the protrusion 32 protrudes. It is set to 40% or less, more preferably 15% or more and 35% or less.

Here, the "inner dimension D2 of the bag body 2 at the position corresponding to the protruding portion 32 in the direction in which the protruding portion 32 protrudes" as used in the present disclosure means that the protruding portion 32 is formed at a position where the protruding portion 32 is formed. It means the dimension from the position of the edge portion 31 to the position of the edge portion 31 facing the edge portion 31 when it is not assumed. The "protruding dimension L1 of the protruding portion 32" here means the protruding dimension L1 of one protruding portion 32. Therefore, when the plurality of projecting portions 32 are located on the straight line T1, the "protruding dimension L1 of the projecting portion 32" means the projecting dimension of one of the plurality of projecting portions 32. ing.

On the other hand, from the viewpoint of ensuring the thermal effect of the heating element 1, the dimension D1 between the protruding portion 32 and the portion facing the protruding portion 32 in the direction in which the protruding portion 32 protrudes is set to the following condition. , The protrusion dimension L1 of the protrusion 32 is set. That is, the dimension D1 is set to be preferably 20% or more and 95% or less, more preferably 25% or more and 85% or less, and further preferably 30% or more and 70% or less with respect to the inner dimension D2.

Here, the base points of the "inner dimension D2" and the "protruding dimension L1" are the centers in the width direction of the protruding portion 32 on the inner peripheral edge of the edge portion 31 (actually, an extension line of the inner peripheral edge forming the storage space). It is a point. The "extension line of the inner peripheral edge forming the storage space" does not actually appear because the protruding portion 32 and the edge portion 31 are integrated, but the inner peripheral edges of the edge portions 31 on both sides of the protruding portion 32 are smoothly connected. It's a virtual line.

Further, the "protruding dimension L1" is the maximum value of the distance between the line parallel to the inner peripheral edge of the edge portion 31 on which the protruding portion 32 is formed and having an intersection with the protruding portion 32 and the inner peripheral edge. .. Further, the "direction in which the protruding portion 32 protrudes" is a direction orthogonal to the inner peripheral edge when the inner peripheral edge of the edge portion 31 on which the protruding portion 32 is formed is linear, and the protruding portion 32 is formed. When the inner peripheral edge of the edge portion 31 is curved, it is a direction orthogonal to the tangent line of the inner peripheral edge at the center point in the width direction of the protruding portion 32 on the inner peripheral edge of the edge portion 31. In the present embodiment, since the inner peripheral edge of the edge portion 31 on which the protruding portion 32 is formed is linear, the “direction in which the protruding portion 32 protrudes” is parallel to the width direction of the heating element 1.

Further, in the present embodiment, the pair of protruding portions 32 are located on the straight line T1. The dimension D1 is the inner dimension D2 minus the sum of the protruding dimensions L1 of the protruding portion 32 (that is, L1 + L1). In this case, D1 = D2- (L1 + L1).

On the other hand, for example, as shown in FIG. 3 (Modification 1) or FIG. 4 (Modification 2-1), when there is only one protrusion 32 on the straight line T1, the dimension D1 starts from the inner dimension D2. The dimension is obtained by subtracting the protrusion dimension L1 of the protrusion 32. In this case, D1 = D2-L1. When a plurality of line segments can be drawn between the protruding portion 32 and the portion facing the protruding portion 32 in the direction in which the protruding portion 32 protrudes, the "dimension D1" here is one of the plurality of line segments. Use the shortest line segment size.

However, the protrusion dimension L1 and the width dimension H1 of the protrusion 32 are not particularly limited. Further, the protruding direction of the protruding portion 32 does not have to be along the width direction of the bag body 2, and may be inclined with respect to the width direction, for example.

The protruding portion 32 according to the present embodiment is formed at the central portion of the bag body 2 in the length direction. The "central portion" here is a position where the dimension from the end in the length direction of the bag body 2 is 1/2 of the length dimension of the bag body 2 (this is the center). Therefore, it means a portion having a certain range in the length direction. As an example, the fixed range is 1/3 of the length dimension of the bag body 2. Therefore, in the present disclosure, if the protruding portion 32 is formed in at least a part of the protruding portion 32 in this fixed range, it is in the category of "formed in the central portion in the length direction of the bag body 2."

The pair of protrusions 32 are located on a straight line T1 in this embodiment. That is, the protruding directions of the plurality of projecting portions 32 are along the straight line T1. In the heating element 1 according to the present embodiment, since the heat generating material 4 does not exist in the portion where the protruding portion 32 is located, it is easy to bend along the straight line T1 at the position of the protruding portion 32.

As shown in FIG. 1, the joint portion 3 is formed with a plurality of (here, two) recesses 33 recessed from the outer edge of the bag body 2. The recess 33 according to the present embodiment is a notch formed at a portion corresponding to the protruding portion 32. The recess 33 may be formed at the time of molding the sheet material, or may be cut out after the bag body 2 is formed. In the present embodiment, the peripheral edge of the recess 33 is formed in an arc shape, but may be formed in an acute angle or an obtuse angle, and is not particularly limited. In the heating element 1 according to the present embodiment, since the recess 33 is formed at the portion corresponding to the protruding portion 32, it becomes easy to bend at the portion corresponding to the protruding portion 32 while maintaining the joint strength of the joint portion 3.

(2) Action and Effect As described above, in the heating element 1 according to the present embodiment, the protruding portion 32 protrudes from the edge portion 31 formed along at least a part of the outer circumference of the bag body 2 toward the heating material 4. According to this, in the heating element 1, the maximum temperature of the heat generating surface can be lowered, and a locally high temperature rise can be suppressed.

Further, the heat generating material 4 enclosed in the bag body 2 is hindered from moving by the protruding portion 32. Therefore, in the heating element 1 according to the present embodiment, the heating material 4 is less likely to be biased inside the bag body 2. Further, the heating element 1 according to the present embodiment is easily bent at a portion along the protruding portion 32, and the user can deform the heating element 1 along the body when the heating element 1 is applied to the body.

Further, in the heating element 1 according to the present embodiment, the protruding dimension L1 of the protruding portion 32 is 15% with respect to the inner dimension D2 of the bag body 2 at the position corresponding to the protruding portion 32 in the direction in which the protruding portion 32 protrudes. More than 35% or less. Therefore, more effectively, in the heating element 1, the maximum temperature of the heating surface can be lowered, a locally high temperature rise can be suppressed, and the heat generating material 4 can be suppressed from being biased inside the bag body 2. be able to.

Further, in the heating element 1 according to the present embodiment, in the direction in which the protruding portion 32 protrudes, the dimension D1 between the protruding portion 32 and the portion facing the protruding portion 32 is at a position corresponding to the protruding portion 32. It is 30% or more and 70% or less with respect to the inner size D2 of the bag body 2. Therefore, according to this aspect, a constant thermal effect can be ensured in the heating element 1.

Further, the heating element 1 according to the present embodiment includes a plurality of protruding portions 32, and the protruding directions of the plurality of protruding portions 32 are along a straight line T1. Therefore, the heating element 1 is likely to bend along the straight line T1, and the user is more likely to deform the heating element 1 along the body when the heating element 1 is applied to the body.

Further, in the heating element 1 according to the present embodiment, a recess is formed at a portion corresponding to the protruding portion 32 on the outer edge of the bag body 2. Therefore, the heating element 1 is more likely to bend along the straight line T1, and the user is more likely to deform the heating element 1 along the body when the heating element 1 is applied to the body.

Further, in the heating element 1 according to the present embodiment, the bag body 2 is formed in a rectangular shape in a front view having a width and a length, and the protruding portion 32 is formed in the central portion in the length direction of the bag body 2. ing. Therefore, in the heating element 1 according to the present embodiment, the maximum temperature can be lowered and the uniformity of the temperature distribution can be improved on the heat generating surface. Moreover, it is possible to suppress the decrease in the average temperature while lowering the maximum temperature of the heat generating surface.

In particular, a large-sized heating element such as the heating element 1 according to the present embodiment is more likely to have a locally high temperature rise than a normal-sized heating element, and the heating material 4 is separated inside the bag body 2. Easy to approach. On the other hand, in the heating element 1 according to the present embodiment, since the joint portion 3 has the protruding portion 32, the maximum temperature of the heating surface is effectively lowered and locally high even in a large size. In addition to being able to suppress the temperature rise, it is possible to prevent the heat generating material 4 from being biased inside the bag body 2.

(3) Modified Example The above embodiment is only one of various embodiments of the present disclosure. The embodiment can be changed in various ways depending on the design and the like as long as the object of the present disclosure can be achieved. Hereinafter, a modified example of the embodiment will be described. The modifications described below can be applied in combination as appropriate.

(3.1) Modification example regarding the number of protrusions (Modification example 1)
The heating element 1 according to the above embodiment has two protrusions 32, but as shown in FIG. 3, it may have only one protrusion 32. In the heating element 1 according to the first modification, the protruding portion 32 protrudes from the long side portion 311 of only one of the pair of long side portions 311.

The protrusion dimension L1 of the protrusion 32 is preferably set to 5% or more, more preferably 10% or more and 40% or less, and further preferably 15% or more and 35% or less with respect to the inner size D2. Further, the protruding dimension of the protruding portion 32 is such that the dimension D1 is preferably 20% or more and 95% or less, more preferably 25% or more and 85% or less, and further preferably 30% or more and 70% or less with respect to the inner dimension D2. L1 is set.

The heating element 1 according to the first modification can also have the same effect as that of the above embodiment.

(3.2) Deformation example of arrangement of protrusions (deformation example 2)
(3.2.1) Modification 2-1
In the heating element 1 according to the above embodiment, two protrusions 32 are formed on a straight line T1, but as shown in FIG. 4, the two protrusions 32 are mutually formed when viewed in the protruding direction of the protrusions 32. It may be off. In the heating element 1 according to the modification 2-1 the pair of protruding portions 32 are formed so as to be offset from each other in the length direction of the heating element 1.

The protrusion dimension L1 of the protrusion 32 is preferably 5% or more, more preferably 10% or more and 40% or less, still more preferably 15% or more and 35% with respect to the inner size D2, like the heating element 1 according to the modified example 1. It is set as follows. Further, the protruding dimension of the protruding portion 32 is such that the dimension D1 is preferably 20% or more and 95% or less, more preferably 25% or more and 85% or less, and further preferably 30% or more and 70% or less with respect to the inner dimension D2. L1 is set.

The heating element 1 according to the modified example 2-1 can also exhibit the same effect as that of the above embodiment.

(3.2.2) Modification 2-2
In the heating element 1 according to the above embodiment, projecting portions 32 are formed on each of the pair of long side portions 311. However, although not particularly shown, they are diagonal of four corner portions 313 (see FIG. 1). The protruding portion 32 may be formed on the pair of corner portions 313.

In the heating element 1 according to the modified example 2-2, the protruding portion 32 protrudes from the edge portion 31 along a diagonal line as a straight line. The pair of protrusions 32 are located diagonally.

The heating element 1 according to the modified example 2-2 can also exhibit the same effect as that of the above embodiment.

The protruding portion 32 may protrude from the short side portion 312 of the edge portion 31.

(3.3) Deformation example of the outer shape of the bag body (deformation example 3)
(3.3.1) Modification 3-1
Although the heating element 1 according to the above embodiment is formed in a substantially rectangular shape in the front view, it may be formed in an oval shape in the front view as shown in FIG. 5 (A). Here, the "oval" as used in the present disclosure means a circle extending in one direction, and includes, for example, an oval shape, an oval shape, an oval shape, a rounded rectangle, and the like.

In the heating element 1 according to the modified example 3-1 the edge portion 31 is formed in a curved shape. The protruding portion 32 protrudes from the edge portion 31 toward the heat generating material 4. The protrusion dimension L1 of the protrusion 32 is preferably set to 5% or more, more preferably 10% or more and 40% or less, and further preferably 15% or more and 35% or less with respect to the inner size D2. Further, the protruding dimension of the protruding portion 32 is such that the dimension D1 is preferably 20% or more and 95% or less, more preferably 25% or more and 85% or less, and further preferably 30% or more and 70% or less with respect to the inner dimension D2. L1 is set.

Here, the base points of the "inner dimension D2" and the "protruding dimension L1" are the centers in the width direction of the protruding portion 32 on the inner peripheral edge of the edge portion 31 (actually, an extension line of the inner peripheral edge forming the storage space). Means a point. The "extension line of the inner peripheral edge forming the storage space" does not actually appear because the protruding portion 32 and the edge portion 31 are integrated, but the inner peripheral edges of the edge portions 31 on both sides of the protruding portion 32 are smoothly connected. It's a virtual line.

Therefore, the same effect as that of the above-described embodiment can be obtained in the heating element 1 according to the modified example 3-1.

(3.3.2) Modification 3-2
Although the heating element 1 according to the above embodiment is formed in a substantially rectangular shape in front view, it may be formed in a D shape in front view as shown in FIG. 5 (B). The shape of the heating element 1 according to the above embodiment is point-symmetrical, but the shape of the heating element 1 according to the modified example 3-2 is not point-symmetrical but line-symmetrical.

In the heating element 1 according to the modified example 3-2, the edge portion 31 includes an arc portion 314 and three straight portions 315. The protruding portion 32 protrudes from the boundary portion between the arc portion 314 and the straight line portion 315 toward the heat generating material 4. The protrusion dimension L1 of the protrusion 32 is preferably set to 5% or more, more preferably 10% or more and 40% or less, and further preferably 15% or more and 35% or less with respect to the inner size D2. Further, the protruding dimension of the protruding portion 32 is such that the dimension D1 is preferably 20% or more and 95% or less, more preferably 25% or more and 85% or less, and further preferably 30% or more and 70% or less with respect to the inner dimension D2. L1 is set.

Similar to the modified example 3-1 the base points of the "inner dimension D2" and the "protruding dimension L1" are the protruding portions 32 on the inner peripheral edge of the edge portion 31 (actually, an extension line of the inner peripheral edge forming the storage space). Means the center point in the width direction of. The "extension line of the inner peripheral edge forming the storage space" does not actually appear because the protruding portion 32 and the edge portion 31 are integrated, but the inner peripheral edges of the edge portions 31 on both sides of the protruding portion 32 are smoothly connected. It's a virtual line.

Therefore, the same effect as that of the above-described embodiment can be obtained in the heating element 1 according to the modified example 3-2.

(3.4) Deformation example of the structure of the bag body (deformation example 4)
In the heating element 1 according to the above embodiment, the bag body 2 is formed by stacking two sheet materials having the same shape and joining the four sides thereof to form a bag shape. As shown in FIG. The bag body 2 may be formed in a bag shape by folding one sheet material and joining the three sides thereof. In the heating element 1 according to the modified example 4, the edge portion 31 is formed along three of the four sides of the bag body 2.

In the heating element 1 according to the modified example 4, one surface of the bag body 2 is the front side sheet portion 21, and the opposite surface is the back side sheet portion 22. The front side sheet portion 21 and the back side sheet portion 22 are integrally formed. The portion pointed to by reference numeral 34 in FIG. 6 is a bent portion. From the viewpoint of ensuring strength, the bent portion 34 may be welded.

The protrusion dimension L1 of the protrusion 32 is preferably set to 5% or more, more preferably 10% or more and 40% or less, and further preferably 15% or more and 35% or less with respect to the inner size D2. Further, the protruding dimension of the protruding portion 32 is such that the dimension D1 is preferably 20% or more and 95% or less, more preferably 25% or more and 85% or less, and further preferably 30% or more and 70% or less with respect to the inner dimension D2. L1 is set.

The heating element 1 according to the modified example 4 can also exhibit the same effect as that of the above embodiment.

Although not shown, a bag-shaped bag body 2 may be formed by using a sheet material in which the back side sheet portion 22 and the front side sheet portion 21 are connected in a tubular shape and joining the two sides thereof. Further, from the viewpoint of ensuring strength, the remaining two sides may be welded.

(3.5) Deformation example regarding the shape of the protruding portion (Deformation example 5)
In the heating element 1 according to the above embodiment, the protruding portion 32 has an elongated shape in the protruding direction, but the shape of the protruding portion 32 may be the shape according to the following modifications 5-1 to 5-6. Good.

(3.5.1) Modification 5-1
In the heating element 1 according to the modified example 5-1, the protruding portion 32 is formed in a semicircular shape as shown in FIG. 7 (A), and the inside corner portion formed by the edge portion 31 and the protruding portion 32 is formed. It has corners, not curves that connect smoothly. The center of the arc forming the edge on the heat generating material 4 side of the protrusion 32 is located on the edge portion 31 or on the heat generating material 4 side of the edge portion 31.

(3.5.2) Modification 5-2
In the heating element 1 according to the modified example 5-2, the projecting portion 32 is formed in a substantially rectangular shape as shown in FIG. 7B, and the projecting portion 32 has a protruding corner portion 321 on the tip side in the protruding direction. Is approximately right angle.

(3.5.3) Modification 5-3
In the heating element 1 according to the modified example 5-3, the protruding portion 32 includes a convex portion 322 and a triangular portion 323 as shown in FIG. 7C. The convex portion 322 is the base portion of the protruding portion 32. The triangular portion 323 protrudes from the tip surface of the convex portion 322 in the protruding direction in the protruding direction. The triangular portion is sharpened so as to become narrower toward the tip.

(3.5.4) Modification 5-4
In the heating element 1 according to the modified example 5-4, the protruding portion 32 is formed in a substantially triangular shape as shown in FIG. 7 (D). The protruding portion 32 is sharpened so as to become narrower toward the protruding direction.

(3.5.5) Modification 5-5
In the heating element 1 according to the modified example 5-5, the protruding portion 32 is formed so as to become wider as it goes in the protruding direction, as shown in FIG. 7 (E). The widthwise edge of the protrusion 32 is curved.

(3.6) Other Modification Examples The other modification examples are listed below.

The heating element 1 according to the above embodiment has two protrusions 32, but may have three or more protrusions 32.

In the heating element 1 according to the above embodiment, the protruding portion 32 is formed at the central portion of the bag body 2 in the length direction, but the protruding portion 32 is located at a position biased toward one end side in the length direction. It may be formed.

The heating element 1 according to the above embodiment and each modification has a recess 33 at a position corresponding to the protrusion 32, but the recess 33 may not be present.

In the present disclosure, expressions with "abbreviation" such as "substantially parallel" or "substantially orthogonal" may be used. For example, "substantially parallel" means that it is substantially "parallel", and includes not only a strictly "parallel" state but also an error of about several percent. The same applies to other expressions with "abbreviations".

Further, in the present disclosure, expressions that distinguish between "... end" and "... end" are used, such as "front end" and "front end". For example, the "front end" means a portion having a certain range including the "front end". The same applies to other expressions with "... end".

(4) Examples The present invention will be described below with reference to examples. However, the present invention is not limited to the following examples.

As Examples 1 to 3, a heating element having a protruding portion at the joint portion is manufactured, and as a comparative example, a heating element having no protruding portion at the joint portion is manufactured, and the temperature of the heat generating surface at the time of heat generation is photographed by thermography. Then, the temperature distribution was compared.

As the heating elements according to Examples 1 to 3 and Comparative Examples, as shown in FIGS. 8A to 8D, the heating surface is formed in a substantially rectangular shape, and the length dimension E1 (longest portion) of the heating surface. ) = 181 mm, and a heating element having a heating surface width dimension W = 116 mm was manufactured. In the heating elements according to Examples 1 to 3 and Comparative Examples, the heating material and the material of the bag body were the same as those in the above embodiment, and all common materials were used. In addition, the amount of heat-generating material in each of Examples 1 to 3 and Comparative Example was 70 g, and all of them had a common weight.

As a heating element according to the first embodiment, as shown in FIG. 8A, a pair of protrusions are formed at a position of E2 = 90.5 mm (that is, the center in the length direction) from one end of the heat generation surface, and each protrusion is formed. The protruding dimension L2 of the portion was set to 20 mm.

As a heating element according to the second embodiment, as shown in FIG. 8B, a pair of protrusions are formed at a position of E2 = 90.5 mm (that is, the center in the length direction) from one end of the heat generation surface, and each protrusion is formed. The protruding dimension of the portion was set to L3 = 35.5 mm.

As a heating element according to the third embodiment, as shown in FIG. 8C, a pair of protruding portions are formed at a position of E3 = 134.75 mm from one end of the heat generating surface, and the protruding dimensions of each protruding portion L3 = 35. It was set to 5 mm.

FIG. 9 shows the results (result 1) taken by arranging Examples 1 and 2 and Comparative Examples side by side using thermography. Further, the area in each temperature range is calculated from the result of photographing by thermography, and the relationship between each temperature range and the area ratio to the whole in the temperature range is shown in Table 1-1. Table 1-2 shows the area ratio of the high temperature range (the temperature range of the maximum temperature of -5 ° C or higher and lower than the maximum temperature) extracted from Table 1-1.

Further, FIG. 10 shows the result (result 2) of the results (result 2) in which the imaging locations were changed from the result 1 and the examples 2 and 3 and the comparative example were side by side and photographed by thermography. Further, the area in each temperature range is calculated from the result of photographing by thermography, and the relationship between each temperature range and the area ratio to the whole in the temperature range is shown in Table 2-1. Table 2-2 shows the area ratio of the high temperature region extracted from Table 2-1.

A graph of Table 1-1 is shown in FIG. 11, and a graph of Table 2-1 is shown in FIG. In the graph, the vertical axis is the area ratio (%) and the horizontal axis is the temperature (° C.).

In Result 1, the maximum temperature was extracted from Table 1-1 for each of Examples 1 and 2 and Comparative Example, and the difference in maximum temperature between Comparative Example and Examples 1 and 2 was calculated. Further, the average temperature on each heat generating surface of Examples 1 and 2 and Comparative Example was calculated, and the difference in average temperature between Comparative Example and Examples 1 and 2 was calculated. The results are shown in Table 3.

In Result 1, as can be seen from FIG. 9, in the comparative example, a white portion showing a high temperature is dark and clearly present in the center of the heat generating surface, but in the heating element according to Examples 1 and 2, the white portion is larger than that in the comparative example. Is also getting thinner. Further, as can be seen from Table 1-1, Table 1-2 and FIG. 11, the heating element according to Examples 1 and 2 has an increased area ratio in the high temperature region as compared with the comparative example, and is the highest. The temperature dropped by 1 ° C to 2 ° C.

In Result 2, as can be seen from FIG. 10, in the comparative example, a white portion showing a high temperature is deeply and clearly present in the center of the heating surface, but in the heating elements according to Examples 2 and 3, the white portion is larger than that in the comparative example. Is also getting thinner. Further, as can be seen from Table 2-1 and Table 2-2 and FIG. 12, the heating elements according to Examples 2 and 3 have substantially the same or higher area ratio in the high temperature region as compared with Comparative Examples. And the maximum temperature dropped by about 1 ° C.

Therefore, in the heating elements according to Examples 1 to 3, the maximum temperature can be lowered while maintaining the area ratio of the high temperature region on the heat generating surface to be equal to or higher than that in the comparative example. In short, in the heating element according to Examples 1 to 3, it is possible to suppress a locally high temperature rise on the heat generating surface.

In particular, as can be seen from Tables 1-2 and 2-2, in the heating elements according to Examples 1 and 2, the area ratio in the high temperature region is increased by about 3.4% to 6.7% as compared with the comparative example. And the maximum temperature was 1 ° C to 2 ° C lower than that of the comparative example. Therefore, it can be seen that when the protruding portion is arranged at a position corresponding to the central portion of the heat generating surface, the maximum temperature of the heat generating surface can be lowered and the area of the high temperature region can be widened as compared with the comparative example. That is, by arranging the protruding portion at a position corresponding to the central portion of the heat generating surface, the uniformity of the temperature distribution of the heat generating surface can be improved.

Further, as can be seen from Table 3, in the heating elements according to Examples 1 and 2, the difference in the maximum temperature is about 1 to 2 ° C. as compared with the comparative example, whereas the difference in the average temperature is 0. It was 1 to 0.6 ° C. That is, in the heating elements according to Examples 1 and 2, in comparison with the comparative example, the decrease in the average temperature was smaller than the decrease in the maximum temperature. That is, by arranging the protruding portion at a position corresponding to the central portion of the heat generating surface, it is possible to suppress the decrease in the average temperature while lowering the maximum temperature of the heat generating surface.

1 Heating element 2 Bag body 21 Front side sheet part 22 Back side sheet part 3 Joint part 31 Edge part 32 Protruding part 33 Recess D2 Inner size 4 Heat generating material

Claims (6)

A bag body formed in a bag shape by the front side sheet part and the back side sheet part,
The heat-generating material enclosed in the bag body and
With
The bag body has a joint portion in which the front side sheet portion and the back side sheet portion are joined.
The joint
With an edge formed along at least a part of the outer circumference of the bag body,
A protruding portion protruding from the edge portion toward the heat generating material side,
including,
Heating element. The protruding dimension of the protruding portion is 15% or more and 35% or less with respect to the inner dimension of the bag body at a position corresponding to the protruding portion in the direction in which the protruding portion protrudes.
The heating element according to claim 1. In the direction in which the protruding portion protrudes, the dimension between the protruding portion and the portion facing the protruding portion is 30% or more 70 with respect to the inner dimension of the bag body at the position corresponding to the protruding portion. % Or less,
The heating element according to claim 1 or 2. Including a plurality of the protrusions
The protruding directions of the plurality of protrusions are in a straight line.
The heating element according to any one of claims 1 to 3. A recess is formed on the outer edge of the bag body at a portion corresponding to the protruding portion.
The heating element according to any one of claims 1 to 4. The bag body is formed in a rectangular shape in a front view having a width and a length.
The edge portion includes a portion formed along the length direction of the bag body.
The protruding portion is formed at the central portion of the bag body in the length direction.
The heating element according to any one of claims 1 to 5.