JP2022172486A - shoe insole - Google Patents

Abstract

[PROBLEMS] To provide an insole that is made up of two types of layers having different hardnesses and that has good fit and support for the sole of the foot.
SOLUTION: An insole 1 has a toe part 4 formed to place the toes, a projecting part 5 formed to place the tips of the metatarsal bones that project most to the left and right of the width of the foot, The sole of the shoe has an arch portion 6 formed so as to be arranged from the metatarsal bone to just below the lateral malleolus, and a heel portion 7 formed so as to be arranged just below the lateral malleolus and behind the calcaneus. At least two foamed resin layers 1 and 2 are arranged on the whole, the two foamed resin layers have different hardness, and the first layer 2 on the upper surface side is an Asker rubber hardness tester (C type). The measured hardness used is 18 or more and 35 or less, and the second layer 3 on the lower surface side has a measured hardness of 40 or more and 75 or less using an Asker rubber hardness tester (C type). It is a foamed resin layer or polyurethane foam with lower resilience than layer 3 .
[Selection drawing] Fig. 2

Description

The present invention relates to shoe insoles.

BACKGROUND ART Laminated structures of footwear having a cushioning layer made of an elastic material that is flexible and has a low impact resilience and an elastic layer made of an elastic material that is relatively harder than the cushioning layer are known (for example, Patent Document 1 ). It is described that the use of this laminated structure in the insole of footwear such as sandals alleviates the burden on the foot due to impact load and continuous load, thereby improving the comfort of the footwear. The document also describes that foamed urethane resin having a modulus of impact resilience of 10% or less is used as the buffer layer, and foamed ethylene vinyl acetate (EVA) resin is used as the elastic layer.

The insole body has at least a toe support portion, and the insole body includes a sheet-like first low-resilience layer made of a low-resilience resin, and a low-resilience low-resilience layer provided on the upper surface of the first low-resilience layer. An insole having a sheet-like second low-resilience layer made of a flexible resin is known (Patent Document 2). This insole is characterized in that the second low-resilience layer and the first low-resilience layer have different hardnesses. Further, in the same document, the hardness of the second low-resilience layer is lower than the hardness of the first low-resilience layer, and the rebound resilience of the second low-resilience layer is lower than the rebound resilience of the first low-resilience layer. It is described that it is preferable to Such an insole can give the insole body almost the same mechanical properties as those of sand, and in use, it is possible to obtain the same shape-up effect and health promotion effect as walking on sand.

Also known is an insole comprising an insole part made of resin and a resin part including a second resin region located on the upper surface thereof, wherein the insole part has a Shore A hardness of 60 or more and 100 or less. (Patent document 3). The document describes that a high rebound member such as a resin such as soft polyurethane or an elastomer having a modulus of rebound resilience of 60% or more is preferable, and a Shore A hardness of 60 or more and 90 or less is preferable. Further, it is preferable that the hardness of the insole part is higher than the hardness of at least a part of the second resin region.

Furthermore, a composite body comprising a midsole body made of synthetic resin foam and a plurality of foamed rubber sheets disposed at least in the area from the ball of the toe to the toe part of the midsole body while shifting them in the front-rear direction. A midsole structure including a seat portion is known (Patent Document 4). The composite seat portion is composed of a single sheet at the toe portion and multiple sheets at the ball of the foot. Examples of synthetic resin foams (that is, foamed resins) forming the midsole body include thermoplastic synthetic resins such as EVA and thermosetting resin foams such as polyurethane (PU). Moreover, foams such as natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, and nitrile-butadiene rubber are mentioned as rubber foams (that is, foamed rubber) constituting the composite sheet portion. In the document, the hardness of the midsole body 2 is preferably set to, for example, 50 to 60C on the Asker C scale, and the hardness of the composite seat portion is preferably set to, for example, 10 to 40C on the Asker C scale. It is said that In addition, it is said that the composite seal portion is preferably made of a material with low hardness and high resilience.
By using such a midsole structure in sports shoes, it is possible to improve the contact with the foot, obtain a high repulsive force when kicking with the toe of the foot, and increase the propulsive force during exercise. It is disclosed in the document that it is possible.

Utility Model Registration No. 3063749 Utility Model Registration No. 3167048 JP 2020-141892 A Japanese Patent Application Laid-Open No. 2020-163082

As described above, various types of insoles composed of two layers of different hardness are known, but no insoles that support the preferred shape of the skeleton of the foot while providing good fit to the sole of the foot have been known. .
SUMMARY OF THE INVENTION An object of the present invention is to provide an insole that is composed of two types of layers having different hardnesses, supports a preferable shape of the skeleton of the foot, and has good fit to the sole of the foot.

The present inventors have found that the problem can be solved by laminating two layers of moldings having a hardness within a specific range, and have completed the present invention.

That is, the insole of the present invention includes a toe part formed to place the toes, a projecting part formed to place the tips of the metatarsal bones that extend the width of the foot to the left and right the most, The entire bottom surface of the shoe, having an arch portion formed so as to be arranged from the metatarsal bones to the area directly below the lateral malleolus, and a heel portion formed so as to be arranged so as to be located directly below the lateral malleolus and the calcaneus behind it. The two layers of foamed resin layers have different hardnesses, and the first layer on the upper surface side has a hardness measured using an Asker rubber hardness tester (C type) is 18 or more and 35 or less, the second layer on the lower surface side has a hardness measured using an Asker rubber hardness tester (C type) of 40 or more and 75 or less, and the first layer has higher resilience than the second layer low foamed resin layer or polyurethane foam.
According to this configuration, when the foot is placed on the insole, the first layer conforms to the shape of the sole of the foot to reduce the gap between the foot and the insole to create a state in which the shape of the sole is taken. , the first layer can softly fit and support the foot. Furthermore, the second layer can be provided with appropriate hardness and cushioning properties so that the skeleton of the foot can be properly held (supported) by the second layer.
The impact resilience of the first layer of the insole of the shoe of the present invention measured by ISO4662:2009 may be 47% or more and 53% or less.
According to this configuration, the insole of the present invention can further enhance the supportability of the skeleton of the foot and the fitability to the sole of the foot.
The second layer of the insole of the shoe of the present invention may have a rebound resilience modulus of 55% or more and 65% or less as measured by ISO4662:2009.
According to this configuration, the insole of the present invention can further enhance the supportability of the skeleton of the foot and the fitability to the sole of the foot.
The first layer of the insole of the shoe of the present invention may be a foamed resin layer containing polyurethane as a main component or a foamed resin containing ethylene-vinyl acetate copolymer as a main component.
With this configuration, the fit of the insole of the shoe of the present invention to the sole can be further enhanced.
The second layer of the insole of the shoe of the present invention may be a foamed resin layer containing an ethylene-vinyl acetate copolymer as a main component.
According to this configuration, the insole of the present invention can further enhance the supportability of the skeleton of the foot and the fitability to the sole of the foot.
The first layer of the insole of the shoe of the present invention may be a foamed resin layer containing polyurethane as a main component, and may have a thickness of 0.5 mm or more and 4.0 mm or less.
With this configuration, the fit of the insole of the shoe of the present invention to the sole can be further enhanced.
The insole of the present invention may include a support plate attached to the lower surface of the second layer and formed of a material harder than the foamed resin of the second layer.
According to this configuration, the insole of the shoe according to the present invention further enhances the supportability of the skeleton of the foot in a preferred form.
The support plate of the insole of the shoe of the present invention is made of hard resin, carbon fiber reinforced resin, glass fiber reinforced resin, or a composite material thereof, and the hardness of the support plate is measured using an Asker rubber hardness tester (D type). May have 40D or greater in measurement.
According to this configuration, the insole of the shoe according to the present invention further enhances the supportability of the skeleton of the foot in a preferred form.

The insole for shoes of the present invention makes the first layer conform to the shape of the sole when the foot is placed to reduce the gap between the foot and the insole to create a state as if the sole is shaped, and is soft. It supports (fits) the foot and provides appropriate hardness and cushioning properties to the second layer to hold (support) the skeleton of the foot. Therefore, the insole of the present invention prevents unnecessary movement of the foot due to the space between the foot and the insole while maintaining the skeleton of the foot as correctly as possible, and suppresses fatigue of the foot. , the movement of the foot can be efficiently transmitted to an object such as the ground through the insole and the footwear.

Fig. 2 is a cross-sectional view of the insole according to one embodiment of the present invention taken along a line substantially central in the width direction (specifically, taken along line AA in Fig. 2(a) or (b)). (a) It is the top view of the insole of one Embodiment of this invention, ie, the figure seen from the 1st layer side. (b) It is the bottom view of the insole of one Embodiment of this invention, ie, the figure seen from the 2nd layer side. (a) It is the schematic diagram which looked at the frame|skeleton of the right foot from diagonally upward. (b) It is the schematic diagram which looked at the skeleton of the right foot from the side of the little finger. FIG. 4 is a bottom view showing an example of a support plate applicable to the insole of one embodiment of the present invention; FIG. 4 is a bottom view showing a state in which an insole according to one embodiment of the present invention is provided with an example of a support plate;

As shown in FIG. 1, the insole 1 comprises two foamed resin layers having different hardnesses.
As shown in FIGS. 2(a) and 2(b), the first layer 2 located on the uppermost surface (excluding the cosmetic cloth sheet) and the second layer 3 located below the first layer 2 are , are formed so that the outer shape when viewed from above and from the bottom is substantially the same.

Both the first layer 2 and the second layer 3 are sized and shaped to cover substantially the entire upper surface of the sole when placed on the shoe.
Specifically, the first layer 2 and the second layer 3 have, from the tip to the rear end, a toe portion 4, an overhanging portion 5 with the widest lateral width, an arch portion 6, and a heel portion 7. ing.
The toe portion 4 is a portion formed so as to place the toes.
The protruding portion 5 is a portion formed so as to place the distal end portion of the metatarsal bone 50 shown in FIG.

The arch portion 6 is a portion formed so as to extend from a part of the metatarsal bone 50 shown in FIG.
The heel portion 7 is a portion formed so as to arrange the calcaneus 62 immediately below the lateral malleolus 61 shown in FIG. 3 and behind it.

The arch portion 6 of the first layer 2 and the second layer 3 mainly includes an inner wall portion 8 formed so as to place the first metatarsal bone 51 shown in FIGS. The outer wall portion 9 formed to place the fifth metatarsal bone 55 shown in FIGS. 3(a) and (b), and the central wall portion formed between the inner wall portion 8 and the outer wall portion 9 10.

The inner wall portion 8 is a portion which is curved in an arch shape protruding upward so as to mainly place the first metatarsal bone 51 shown in FIG. 3 and whose end portion is raised smoothly upward.
The outer wall portion 9 is a portion that is curved into an arch shape protruding upward so that the fifth metatarsal bone 55 shown in FIG.

As shown in FIGS. 1 and 2, the heel portions 7 of the first layer 2 and the second layer 3 are slightly raised so as to surround and hold the lower end portion of the heel of the foot from the lateral side. ing.

As shown in FIG. 2( a ), on the upper surface of the first layer 2 and substantially at the center in the width direction of the central wall portion 10 , a raised central convex portion 14 extending in the front-rear direction is formed. The central convex portion 14 is formed so as to fit the depression of the foot immediately behind and inside the ball of the big toe that supports the body weight when standing on tiptoes. Both left and right sides of the central protrusion 14 are relatively slightly recessed.

The foamed resin layer of the first layer 2 is made of synthetic resin or the like. Specifically, for the first layer 2, it is preferable to use a foamed resin containing polyurethane resin, ethylene-vinyl acetate copolymer (EVA), or the like as a main component.

When the first layer 2 is a foamed resin containing EVA as a main component, the hardness measured using an Asker rubber hardness tester (C type) is not necessarily limited, but is 18 or more and 35 or less, preferably 19 or more and 30 or less, 22 or more and 28 or less are more preferable.
The first layer 2 is made of foamed resin having a lower modulus of impact resilience than the second layer 3 .
When the first layer 2 is a foamed resin containing EVA as a main component, the rebound resilience of the foamed resin layer of the first layer 2 measured according to ISO4662:2009 is not particularly limited, but is preferably 47% or more and 53% or less. More preferably, it is 49% or more and 52% or less. In order to adjust the modulus of rebound resilience, the first layer 2 may be made of a resin layer mixed with an impact absorbing material such as polyethylene, polypropylene, silicone resin, or the like.

When the first layer 2 is a foamed resin containing polyurethane resin as a main component, the polyurethane foamed resin used has lower hardness and low resilience than the second layer 3 .

As the second layer 3, specifically, it is preferable to use a foamed resin containing EVA or the like as a main component.
The hardness of the foamed resin layer of the second layer 3 measured using an Asker rubber hardness tester (C type) is 40 or more and 75 or less, preferably 45 or more and 65 or less, and more preferably 53 or more and 60 or less.
The impact resilience of the second layer 3 measured according to ISO4662:2009 is not particularly limited, but is preferably 55% or more and 65% or less, more preferably 57% or more and 59% or less.

In order to adjust the modulus of rebound resilience, it is conceivable to use a resin layer in which a shock absorbing material such as polyethylene, polypropylene, or silicon resin is mixed. Furthermore, in order to adjust the rebound resilience, it is conceivable to use a resin obtained by compressing a foamed resin containing EVA as a main component.

Although the first layer 2 is not particularly limited, it is preferable that the first layer 2 and the second layer 3 are pressed to have a thickness of 0.5 mm or more and 4.0 mm or less. .
In addition, the second layer 3 is not particularly limited, but is formed with a thickness of 1.0 mm or more and 4.0 mm or less in a state in which the first layer 2 and the second layer 3 are pressed. is preferred. A sheet layer made of fibers is typically provided on the upper surface of the first layer 2 .

The thickness ratio between the first layer 2 and the second layer 3 in the state where the first layer 2 and the second layer 3 are pressed is not necessarily limited, but the first layer 2 and the second layer 3 are formed of EVA foamed resin or as a main material, the overall ratio of first layer 2:second layer 3 should be in the range of 1:0.8 to 1:1.5. In other words, the second layer 3 should be in the range of approximately 0.8 to 1.5 times the first layer 2 .

More specifically, in the above case, the thickness ratio in the toe portion 4 is preferably about 1:0.8 to 1:1.1. : Second layer 3 = 1:0.9 to 1:1.1, more preferably about 1:0.9. In other words, in the toe portion 4, the second layer 3 is preferably about 0.8 to 1.1 times the first layer 2, and is about 0.9 to 1.1 times. is more preferable, and about 0.9 times is even more preferable.

Further, when the structures of the first layer 2 and the second layer 3 are the same as above, the thickness ratio of the overhang portion 5 and the heel portion 7 is first layer 2:second layer 3=1:1.3 to 1: The first layer 2: second layer 3 is preferably in the range of 1.6, more preferably 1:1.4 to 1:1.5, and even more preferably about 1:1.4. preferable. In other words, in the overhang portion 5 and the heel portion 7, the second layer 3 should be in the range of about 1.3 to 1.6 times the first layer 2, and 1.4 to 1.5 times the thickness of the first layer 2. A range of 5 times is more preferable, and about 1.4 times is even more preferable.

The thickness ratio between the first layer 2 and the second layer 3 in the state where the first layer 2 and the second layer 3 are pressed is as follows: When both layers are formed of EVA foamed resin or as a main material, the overall ratio of first layer 2:second layer 3 = 1:1 to 2:1 is not necessarily limited. should be in In other words, the thickness of the first layer 2 should be in the range of 1 to 2 times that of the second layer 3 .

More specifically, in the above case, the thickness ratio in the toe portion 4 may be from about 1:1 to 1.5:0.8. More preferably, the second layer 3=1:1 to 1.5:0.9, and even more preferably 1:0.9 to 1.5:0.9. In other words, in the toe portion 4, the first layer 2 may be about 1 to 1.88 times, more preferably about 1 to 1.67 times, the second layer 3. Even more preferably, it is about 1.1 times to 1.67 times.

Further, when the structures of the first layer 2 and the second layer 3 are the same as above, the thickness ratio of the overhang portion 5 and the heel portion 7 is not particularly limited, but the first layer 2:second layer 3=1:1. to 2:1, and more preferably the first layer 2:second layer 3=1:1 to 1.5:1. In other words, in the overhang portion 5 and the heel portion 7, the first layer 2 may be in the range of 1 to 2 times the second layer 3, and may be in the range of about 1 to 1.5 times. is preferred.

The foamed resin of the first layer 2 and the second layer 3 used in this embodiment may be formed of a foaming resin composition containing a resin composition and a foaming agent, and the resin composition is crosslinked and It may be a crosslinked foam that has been foamed.

The foaming agent is not particularly limited as long as it generates a gas required for foaming the resin composition by heating. It may be used individually by 1 type, or may be used in combination of 2 or more type. The content of the foaming agent in the entire foamed resin body is preferably 0.5% by mass to 10% by mass, more preferably 2% by mass to 5% by mass, relative to the entire resin composition. This is because if it is less than 0.5% by mass, it may not be possible to stably foam. This is because there arises an inconvenience that the voltage varies.

Each of the foamed resins of the first layer 2 and the second layer 3 used in the present invention contains a cross-linking agent, a cross-linking aid, a foaming aid, a vulcanization accelerator, a processing aid and a reinforcing agent in each resin composition described above. etc., and cross-linking and foaming under predetermined conditions.

The cross-linking agent is not particularly limited, and an organic peroxide or the like that promotes general peroxide cross-linking as a cross-linking agent for resins is used. These may be used individually by 1 type, or may be used in combination of 2 or more type. The content of the cross-linking agent with respect to the entire foamed resin body is preferably 1% by mass to 7% by mass, more preferably 2% by mass to 5% by mass, relative to the entire resin composition. This is because if the content is less than 1% by mass, the impact resilience may decrease due to insufficient cross-linking, and if the content is greater than 7% by mass, the cross-linking proceeds excessively, resulting in insufficient foaming. This is because there are cases.

The cross-linking aid is not particularly limited, and may be used singly or in combination of two or more. The content of the cross-linking aid with respect to the entire foamed resin body is preferably 1% by mass to 10% by mass, more preferably 3% by mass to 5% by mass, relative to the entire resin composition. This is because if it is less than 1% by mass, the cross-linking may not proceed sufficiently and the impact resilience may decrease. This is because it may be difficult to reduce the weight of the product.

The foaming aid is not particularly limited, and a urea compound, a zinc compound, or the like is used. These may be used individually by 1 type, or may be used in combination of 2 or more type. The content of the foaming aid relative to the entire foamed resin is preferably 0.5% by mass to 10% by mass relative to the entire foamed resin composition. The standard is to add the same amount of foaming aid as the foaming agent, and if the amount of foaming aid added is less than that of the foaming agent, some foaming agents generate formaldehyde, etc. need to adjust.

From the viewpoint of improving the fluidity and lubricity of the resin composition, suppressing adhesion to kneaders such as rollers, and improving the release effect, the foamed resin may contain a processing aid. The content of the processing aid with respect to the entire foamed resin is preferably 0% by mass to 2% by mass. This is because if the content is more than 2% by mass, the lubricity becomes too high, which may cause the material to slide on the roller, making it difficult for the material to mix during roller processing.

A reinforcing agent may be contained from the viewpoint of improving mechanical properties such as tensile strength and wear resistance of the foamed resin. The content of the reinforcing agent with respect to the entire foamed resin is preferably 5% by mass to 50% by mass based on the entire foamed resin composition. This is because if it is less than 5% by mass, sufficient strength may not be obtained. Because there is

As an example of forming a foamed resin, first, raw materials such as a base resin composition, a cross-linking agent, and a foaming agent are put into a kneader and kneaded to prepare a foamed resin composition. (Kneading process). In this case, the resin composition, the cross-linking aid, the reinforcing agent, the cross-linking agent, the foaming aid and the foaming agent are added in this order to a roll heated to a predetermined temperature (for example, the surface temperature is 40 to 60° C.). After kneading, preforming such as sheeting and pelletizing is performed.

Next, the foamed resin composition obtained in the kneading step is filled in a mold and subjected to heat treatment to promote foaming by the foaming agent. A foamed resin having a shape is produced (foam molding step). In this case, the heating temperature in the heat treatment varies depending on the types of the foaming agent and foaming assistant, but the heat treatment is performed at a temperature (for example, 120 to 180° C.) higher than the decomposition temperature of the foaming agent used.

In the insole 1 of the present invention formed as described above, by imparting appropriate hardness and resilience to the foamed resin of the second layer 3, displacement and distortion of the skeleton of the foot are suppressed, and the arch shape of the arch of the foot is suppressed. , and the shape and position of the entire foot can be maintained.

Further, on the second layer 3, a first layer 2 of foamed resin or polyurethane foam having appropriate hardness and resilience, which is lower than the second layer 3 in hardness and rebound resilience, is formed. Since the first layer 2 of resin is provided, the first layer 2 can be fitted to the uneven shape of the sole.

In addition, by imparting an appropriate hardness to the first layer 2, unlike the conventional insole 1, which gives a sandy walking effect that intentionally places a load on the sole of the foot, the first layer 2 can be applied to the foot. By moderately supporting the sole, the first layer 2 can be easily grasped, and the load on the sole during walking can be reduced.
Moreover, by appropriately setting the thickness ratio of the first layer 2 and the second layer 3, the function of the insole of the present invention can be further exhibited.

As a result, the insole 1 of the present invention maintains the skeleton of the foot as correctly as possible mainly by the second layer 3, and the space between the foot and the insole 1 mainly by the first layer 2 creates a space between the foot and the foot. can prevent unnecessary movement. As a result, the insole 1 of the present invention has the effect of suppressing foot fatigue and efficiently transmitting the movement of the foot to an object such as the ground through the insole 1 and the footwear.

Further, with continued use of the insole 1 of the present invention, it becomes difficult for the first layer 2, in particular, to elastically recover, and the insole 1 is almost solidified in the shape of the sole of the foot. On the other hand, low resilience remains in areas where the foot pressure is relatively light. Therefore, the insole 1 of the present invention has the effect of taking a mold of the foot. It is possible to obtain the effect that the insole 1 can be formed in accordance with the foot.

In addition, the insole 1 of the present invention only needs to include at least the foamed resin of the first layer 2 and the second layer 3 described above, and a plurality of layers of the first layer 2 may be provided on the second layer 3. . Specifically, for example, an EVA foamed resin layer and a polyurethane layer having the configuration of the first layer 2 may be provided on the second layer 3 .

In addition, the insole 1 may have a support plate bonded to the lower surface of the second layer 3 over at least the arch portion 6 and the heel portion 7 and formed of a material harder than the foamed resin of the second layer 3. .

The support plate is formed similarly to the support plate 30 described in PCT/JP2020/040727 shown in FIG. may have been

For example, as described in PCT/JP2020/040727, the support plate 30 shown in FIG. A through hole 18 is formed at a position corresponding to the wall portion 8 and the outer wall portion 9 . Further, the support plate 30 is formed with an opening 19 for receiving and absorbing the load applied by the heel with the heel portion 7 of the first layer 2 and the second layer 3 .

The support plate 30 is used by adhering it to the insole 1 as shown in FIG. Reference numerals 11 and 12 in FIG. 5 indicate the second layer 3 fitted in the through hole 18. As shown in FIG.
The support plate may be made of hard resin, carbon fiber reinforced resin, glass fiber reinforced resin, or a composite material thereof.

Further, the hardness of the support plate may be 40D or more, preferably 40D or more and 80D or less, more preferably 40D or more and 72D or less, as measured using an Asker rubber hardness tester (D type). good.

By attaching the support plate as described above to the back surface of the second layer, it is possible to impart a more stable and comfortable support effect to the skeleton of the foot.

EXAMPLES The present invention will be described in detail below using examples, but the scope of the present invention is not limited to the examples.

Ethylene-vinyl acetate copolymer (EVA) foamed resin (first layer 2) with a hardness of 28 measured using an Asker rubber hardness tester (C type) and EVA with a hardness of 53 measured using an Asker rubber hardness tester (C type) A two-layer plate-like laminate was formed by laminating the foamed resin (second layer 3). An insole 1-1 was produced by die-cutting the obtained plate-like laminate so as to fit the insole of a shoe. An EVA foamed resin layer having a measured hardness of 28 was placed on the upper side of the insole 1 and used.

The same insole as in Example 1, except that EVA foamed resin (first layer 2) with a measured hardness of 19 was used instead of EVA foamed resin with a measured hardness of 28 using an Asker rubber hardness tester (C type). 1-2 was produced. An EVA foamed resin layer having a measured hardness of 19 was placed on the upper side of the insole 1 and used.

Polyurethane foam (first layer 2) and EVA foam resin (second layer 3) having a hardness of 45 measured using an Asker rubber hardness tester (C type) were laminated to form a two-layer plate-like laminate. Insoles 1-3 were produced by die-cutting the plate-like laminate so as to fit the insoles of shoes. In addition, the polyurethane foam layer was used on the upper side of the insole 1 .

Insole 1 similar to Example 3, except that EVA foamed resin (second layer 3) with a measured hardness of 63 was used instead of EVA foamed resin with a measured hardness of 45 using an Asker rubber hardness tester (C type). -4 was made. In addition, the polyurethane foam layer was used on the upper side of the insole 1 .

[Comparative Example 1]
Insole 1- similar to Example 1 except that EVA foamed resin (first layer 2) with a measured hardness of 38 was used instead of EVA foamed resin with a measured hardness of 28 using an Asker rubber hardness tester (C type) 5 was produced. An EVA foamed resin layer having a measured hardness of 38 was placed on the upper side of the insole 1 and used.

(Evaluation method)
Adult male A with a height of about 176 cm and a weight of 73 kg, adult male B with a height of about 162 cm and a weight of 53 kg, adult male C with a height of about 172 cm and a weight of 75 kg, adult female D with a height of about 159 cm and a weight of 49 kg, a height of about 164 cm and a weight of 58 kg The insoles 1 of Examples 1 to 4 and Comparative Example 1 were placed on sports shoes and worn by an adult female E, and the feeling of use was evaluated after walking on the asphalt for about 1 hour. The feeling of use was evaluated based on the presence or absence of any of (1) feeling of support on the sole, (2) feeling of fit (per foot), and (3) pain or fatigue on the sole when walking for about 1 hour. .

In this embodiment, the "feeling of support" means whether or not there is a sense that the sole of the foot is held by the insole 1, and the "feeling of fit" refers to the feeling of fitting to the shape of the sole. It means whether or not the foot is supported softly in a state of close contact with each other. The evaluation results of each insole 1 are shown in Tables 1-5. In addition, (1) feeling of support on the sole and (2) feeling of fit (per foot) were evaluated in the following five grades.
5-step evaluation a. I strongly agree b. I think so c. Neither d. Not so sure e. I don't think so at all

According to the above examples, the insoles (Examples 1-1 to 1-4) in which the first layer 2 and the second layer 3 are within the scope of the present invention generally provide appropriate support and fit for the feet, It was found that walking for at least about 1 hour does not easily cause pain or fatigue in the feet.

From the above facts, the insole of the present invention provides the second layer 3 with an appropriate hardness to exhibit cushioning and support properties for the foot, and the first layer 2 has a hardness lower than that of the second layer 3. and fit due to low resilience. As a result, the insole of the present invention prevents the occurrence of burdens such as fatigue on the sole while minimizing the space by making the first layer 2 conform to the shape of the sole and softly supporting the foot (feeling of fit). It can be held (supported) without difficulty. Therefore, it can be said that the insole of the present invention has the effect of retaining the skeleton of the foot as correctly as possible and maintaining the condition of the foot in a favorable manner during foot exercise.

As described above, when the insole of the present invention is used, a good feeling of fitting to the sole is obtained. It can be used in the field of footwear such as running shoes, walking shoes, working shoes, and business shoes.

1 Insole 2 First layer 3 Second layer 4 Toe 5 Overhang 6 Arch 7 Heel 30 Support plate

Claims (8)

The toe part is formed to place the toes, the overhang part is formed to place the tip of the metatarsal bone that protrudes the most from side to side, and the area from the metatarsal bone to just below the lateral malleolus. At least two layers of foamed resin disposed over the bottom surface of the shoe, having an arch portion formed to accommodate and a heel portion formed to accommodate the calcaneus directly below and behind the lateral malleolus. with
The two foamed resin layers have different hardnesses,
The first layer on the upper surface side has a measured hardness of 18 or more and 35 or less using an Asker rubber hardness tester (C type),
The second layer on the lower surface has a hardness measured using an Asker rubber hardness tester (C type) of 40 or more and 75 or less,
An insole for shoes, wherein the first layer is a foamed resin layer or polyurethane foam having a lower resilience than the second layer. 2. The insole for shoes according to claim 1, wherein said first layer has a rebound resilience of 47% or more and 53% or less as measured by ISO4662:2009. The insole for shoes according to claim 1 or 2, wherein the second layer has a rebound resilience of 55% or more and 65% or less as measured by ISO4662:2009. The insole for shoes according to any one of claims 1 to 3, wherein the first layer is a foamed resin layer containing polyurethane as a main component or a foamed resin containing ethylene-vinyl acetate copolymer as a main component. The insole for shoes according to any one of claims 1 to 4, wherein the second layer is a foamed resin layer containing an ethylene-vinyl acetate copolymer as a main component. The insole according to any one of claims 1 to 5, wherein the first layer is a foamed resin layer containing polyurethane as a main component and has a thickness of 0.5 mm or more and 4.0 mm or less. The insole according to any one of claims 1 to 6, further comprising a support plate attached to the lower surface of the second layer and made of a material harder than the foamed resin of the second layer. The support plate is made of hard resin, carbon fiber reinforced resin, glass fiber reinforced resin, or a composite material thereof,
8. The insole for shoes according to claim 7, wherein the hardness of the support plate is 40D or more as measured using an Asker rubber hardness tester (D type).

Images