Insoles and footwear

Abstract

To provide an insole or the like capable of improving style, design of footwear and comfort in a well-balanced manner. [Solution] According to one aspect of the present invention, an insole is provided that is placed inside footwear and has a front portion of a first thickness, a rear portion of a second thickness that is thicker than the first thickness, and a central portion that changes from the second thickness to the first thickness, and has a receiving portion that stops the foot from sliding forward.

Description

[Technical Field]

[0001] The present invention relates to an insole and footwear. [Background technology]

[0002] Patent Document 1 discloses an insole that includes a base that supports at least the front of the sole of a user's foot, and the base is provided with a protrusion that is positioned on the sole side of the metatarsophalangeal joint of the user's big toe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-023691 Summary of the Invention [Problem to be solved by the invention]

[0004] It is possible to improve the style of footwear by thickening the insole, but thickening the insole requires that the upper of the footwear be designed to be raised to match, which can easily reduce the design.However, if the thickness of the toe side of the insole is reduced in order to improve the design, the foot can easily slip forward, reducing comfort. In view of the above circumstances, the present invention provides an insole or the like that can improve style, footwear design, and footwear comfort in a well-balanced manner. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided an insole to be placed inside footwear, the insole having a front portion of a first thickness, a rear portion of a second thickness that is thicker than the first thickness, and a central portion that changes from the second thickness to the first thickness, and having a receiving portion that stops the foot from sliding forward.

[0006] According to this aspect, an insole or the like can be provided that can improve style, footwear design, and footwear comfort in a balanced manner. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of the appearance of footwear 1. FIG. [Figure 2] FIG. 2 is a view of the insole 10 as seen from the bottom side. [Figure 3] FIG. 2 is a view of the insole 10 as seen from the right side. [Figure 4] FIG. 2 is a view of the insole 10 as seen from the left side. [Figure 5] 3 is a diagram showing the thickness of each part of the insole 10. FIG. [Figure 6] FIG. 2 is a diagram showing the composition of the insole 10. DETAILED DESCRIPTION OF THE INVENTION

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Various features shown in the following embodiments can be combined with each other.

[0009] FIG. 1 is a diagram showing an example of the appearance of footwear 1. For simplicity of explanation, FIG. 1 and the following figures show footwear for the right foot, but naturally, footwear for the right and left feet can be used as a pair. Footwear 1 is a low-heeled shoe (also called a flat shoe) with a relatively low heel height. Footwear 1 includes an insole 10 and a footwear body 2 on which the insole 10 is placed. Footwear body 2 includes an outsole 3, an upper 4, shoelaces 5, and a heel tab 6.

[0010] The outsole 3 is the bottom layer of the footwear 1 that comes into contact with the ground and is made of a wear-resistant material, providing anti-slip and shock absorption when walking. The upper 4 is the outer part that covers the instep and sides of the foot, forming the shape and appearance of the footwear 1 and designed with breathability and fit in mind. The shoelaces 5 are provided as fastenings for the upper 4 and adjust the fit to the foot by tightening the opening of the footwear 1. The heel tab 6 is a protruding part provided at the rear of the heel of the footwear 1 and has the auxiliary function of making it easier to put on and take off the footwear 1. The insole 10 is the inner sole that comes into contact with the sole of the foot inside the footwear 1 and serves to improve comfort and cushioning.

[0011] The details of the insole 10 will be described with reference to the external appearance of the insole 10. Fig. 2 is a view of the insole 10 as seen from the bottom side. Fig. 3 is a view of the insole 10 as seen from the right side. Fig. 4 is a view of the insole 10 as seen from the left side. Fig. 5 is a diagram showing the thickness of each part of the insole 10. The right side view is a view of the insole 10 as seen from the left side when viewed from the front (from the front), and the left side view is a view of the insole 10 as seen from the right side when viewed from the front (from the front). In Figs. 2 to 4, arrows indicate the front-to-rear, up-down, and left-to-right directions when the insole 10 is placed on an installation surface with the bottom surface 14 facing the installation surface.

[0012] The insole 10 comprises a front portion 11, a central portion 12, and a rear portion 13. The front portion 11 is the portion that constitutes the toe side. The rear portion 13 is the portion that constitutes the heel side. The central portion 12 is the portion that connects the front portion 11 and the rear portion 13. The front portion 11 has a first thickness at its center in the left-right direction. The rear portion 13 has a second thickness at its center in the left-right direction that is thicker than the first thickness. The central portion 12 is the portion that changes from the second thickness to the first thickness. The thickness change of the central portion 12 may be linear, or may be a gradual change in a curved line.

[0013] The first thickness is 5 mm. The second thickness is 12 mm. If the second thickness is 12 mm, when a user wears footwear 1, the user's heel will be 7 mm higher than if the second thickness were the same as the first thickness, making the user's legs appear longer and, as a result, appear taller. On the other hand, if the first thickness is 5 mm, the foot will fit inside footwear 1 even if the portion of upper 4 located above front part 11 is designed to be thin and not raised. According to this embodiment, the heel can be made higher to make the user appear taller, while the toe side can be made thinner to reduce the bulge in the front of the footwear.

[0014] The first thickness may be 5 mm or less. Specifically, the first thickness may be, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5 mm, or may be within a range between any two of the values ​​exemplified here.

[0015] The second thickness may be 12 mm or more. Specifically, the second thickness may be, for example, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27 , 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, 40 mm, and may be within a range between any two of the values ​​exemplified here.

[0016] The thinner the first thickness, the thinner the upper 4 can be designed, improving the appearance of the footwear 1. Furthermore, the thicker the second thickness, the higher the user's heel can be made, making the user appear taller with longer legs. Furthermore, because the heel is raised by the insole 10, the appearance of the footwear 1 can be made to look no different from regular footwear. However, the greater the difference between the first thickness and the second thickness, the more likely the foot will be tilted forward and slip down.

[0017] Therefore, the insole 10 is provided with a receiving portion that receives the foot when it slides forward. The insole 10 is provided with a first receiving portion 21 and a second receiving portion 22 as the receiving portion.

[0018] The first receiving portion 21 is a portion of the front portion 11 that is warped upward on the tip 111 side. The degree of warping of the first receiving portion 21 is shown in the L1 cross section in FIG. 5. The L1 cross section is a cross section taken along the line L1 connecting the tip 111 to the rear end 131 of the insole 10. The first receiving portion 21 warps up to a position where the tip 111 is 9 mm away from the contact surface M1 where the insole 10 is placed on the ground. The amount of warping of the first receiving portion 21 may be constant, or the warping may be greater toward the tip. The first receiving portion 21 comes into contact with the toe side of the sole of the foot and absorbs the force that causes the toe side of the foot to slide forward, thereby preventing the foot from slipping forward compared to when the tip 111 is not warped at all.

[0019] It is desirable that the first receiving portion 21 bends to a position where the tip 111 is at least 7 mm away from the ground surface M1. However, if the tip 111 bends too much, the tip side of the upper 4 needs to be raised upward to ensure space for the fingertips, so it is necessary to keep the bend to a level that does not cause the shape of the upper 4 to collapse.

[0020] The second receiving portion 22 is formed in the rear portion 13. As will be described later, the insole 10 is formed to flex slightly when the user applies weight, and weight applied particularly from the heel creates an elliptical flexure 23 as shown in FIG. 2. The front half of the flexure 23 forms an oblique slope to prevent the foot from sliding forward. In this way, the second receiving portion 22 is the front half of the portion (flexure 23) that flexes when pressed by the heel in the center of the rear portion 13. According to this embodiment, the heel is less likely to slip forward than if the rear portion 13 did not flex at all.

[0021] Next, the composition of the insole 10 will be described. Fig. 6 is a diagram showing the composition of the insole 10. As shown in Fig. 6, the insole 10 is formed using polyurethane, a foaming agent, a catalyst, and minor components as raw materials. The "%" shown in Fig. 6 represents the content of each raw material in mass percent.

[0022] The insole 10 has a polyurethane content of 98% or more and 98.5% or less. Examples of polyurethane that can be used include polyether polyurethane, polyester polyurethane, and thermoplastic polyurethane (TPU). Polyether polyurethane is resistant to hydrolysis, suitable for long-term use, and has excellent flexibility and cushioning properties. On the other hand, polyester polyurethane has high resilience and abrasion resistance, and can improve shape retention. Thermoplastic polyurethane also has the advantage of being easy to mold and allowing for stable control of the size and distribution of foam cells.

[0023] In either case, polyurethane combines flexibility and elastic recovery. In particular, polyurethane has high deformation recovery even when subjected to repeated loads, and is resistant to so-called "sagging." This makes it easy for the insole 10 to maintain its shape even after long-term use. In addition, polyurethane has excellent hydrolysis resistance, oxidation resistance, and weather resistance, making it less likely to harden or crack over time. Therefore, the performance of the insole 10 can be stably maintained even when used outdoors or stored for long periods of time.

[0024] If the insole deteriorates, for example, even if the rear portion 13 is 12 mm thick, the user's weight may cause excessive deformation, resulting in a thickness of less than 10 mm, significantly reducing the effect of making the user appear taller. In contrast, polyurethane is a material that does not deteriorate easily, so by increasing the polyurethane content as described above, it is possible to suppress insole deterioration compared to when the polyurethane content is lower, and it is possible to prevent the loss of the effect of making the user appear taller.

[0025] Polyurethane is a material that can stably form fine foam cells, providing both adequate cushioning and light weight. When subjected to external force, the internal air bubbles deform to absorb the shock, and then return to their original shape when the load is removed. This effectively absorbs shock during walking while providing a comfortable fit that reduces fatigue. The insole 10 contains a foaming agent and a catalyst to form the foam cells.

[0026] Examples of foaming agents that can be used include water, azodicarbonamide (ADCA), oxybis(benzenesulfonylhydrazide), etc. These foaming agents generate gas (CO or N) in polyurethane by heating or chemical reaction, and form fine foam cells in the insole 10.

[0027] Examples of catalysts that can be used include amine catalysts (triethylenediamine (TEDA), dimethylcyclohexylamine (DMCHA), etc.) and tin catalysts (dibutyltin dilaurate (DBTDL), etc.). Amine catalysts promote the reaction between isocyanate and water and control the gas generation reaction from the blowing agent. On the other hand, tin catalysts promote the urethane bond formation reaction and adjust the balance between resin hardening and foaming.

[0028] The insole 10 has a foaming agent content of 0.005% or more and 0.006% or less. The insole 10 also has a catalyst content of 0.002% or more and 0.015% or less. By incorporating the foaming agent and catalyst, the insole 10 reduces shock transmission by 60% or more based on the DIN standard ratio. The DIN standard ratio refers to a percentage or ratio compared to a reference value (standard value) established based on German industrial standards (DIN: Deutsches Institut fur Normung). Note that other standards may be used that represent an equivalent degree of shock transmission reduction, in addition to the DIN standard ratio.

[0029] Since suppressing shock transmission means absorbing shock, the repulsive force that the foot receives from the insole 10 is reduced compared to when the foaming agent content is lower, improving comfort. On the other hand, if the foaming agent content is too high, the insole 10 becomes too soft and, similar to when it deteriorates, deforms excessively due to the user's weight, significantly reducing the effect of making the user appear taller. In the example of Figure 6, by keeping the amount of foaming agent to an appropriate amount, appropriate deformation is achieved, achieving both the effect of making the user appear taller and comfort.

[0030] The portion of the footwear body 2 where the insole 10 is placed is called the midsole 7. The midsole 7 has substantially the same shape and size as the bottom surface 14 of the insole 10. This allows the midsole 7 to uniformly support the force applied to the insole 10 from the user's foot, and makes it possible to suppress changes in the shape of the bottom surface 14 compared to when the shape or size of the midsole 7 is different from that of the bottom surface 14.

[0031] The structure and materials of the midsole 7 will now be described. The midsole 7 is formed integrally or separately on the interior bottom of the footwear body 2, and is a support base that supports the bottom surface 14 of the insole 10 from below. The midsole 7 serves to evenly distribute the load applied to the insole 10 while ensuring the rigidity of the entire shoe. Materials that can be used for the midsole 7 include thermoplastic resins (such as polypropylene, polyethylene, or EVA (Ethylene-Vinyl Acetate) resin), fiber-reinforced plastics (FRP), and laminates made of natural or synthetic leather. These materials are lightweight yet have excellent bending rigidity and dimensional stability.

[0032] The midsole 7 is integrated with the outsole 3 of the footwear body 2 by adhesion or vulcanization. This reduces the likelihood of a gap occurring between the midsole 7 and the outsole 3, ensuring stable support of the bottom surface 14 of the insole 10 during load transmission. With this configuration, the midsole 7 suppresses deformation of the bottom surface 14 even when the insole 10 bends, improving the shape retention and durability of the entire footwear 1.

[0033] <Modification: Other Configurations> In the above example, the insole 10 is formed primarily from polyurethane, but this is not limiting. The primary material of the insole 10 may be, for example, a thermoplastic resin (such as polypropylene, polyethylene, or EVA resin), a fiber-reinforced resin, or an elastic material such as natural or synthetic leather. The primary material of the insole 10 is preferably a material that is resistant to deterioration and has appropriate elasticity. Elasticity may also be imparted by foaming with a foaming agent.

[0034] The insole 10 may be detachably disposed on the midsole surface 7 of the footwear body 2. This allows the insole 10 to be easily replaced. An adhesive layer or a hook-and-loop fastener may be provided on the bottom surface 14 of the insole 10 to detachably fix it to the midsole surface 7.

[0035] The insole 10 may also have a two-layer structure in which a non-foamed layer is laminated on the upper surface of a foamed layer. By providing a non-foamed layer, abrasion resistance and stain resistance can be improved compared to when a non-foamed layer is not provided. The insole 10 may also have a two-layer structure in which a non-foamed layer is laminated on the lower surface of a foamed layer. By laminating a non-foamed layer on the lower surface of the foamed layer, the shape retention and dimensional stability of the insole 10 can be improved. This prevents excessive deformation of the foamed layer and changes in thickness even when the user repeatedly walks or runs, and allows for stable comfort to be maintained for a long period of time.

[0036] Furthermore, the insole 10 may have a three-layer structure in which non-foamed layers are laminated on both the top and bottom surfaces of a foamed layer. With this configuration, the non-foamed layer on the top surface prevents wear and dirt, and the non-foamed layer on the bottom surface suppresses deformation, thereby further improving the durability, cleanliness, and elastic stability of the insole 10 as a whole.

[0037] The average diameter or density of the foam cells formed in the insole 10 may be smaller in the rear portion 13 than in the front portion 11. This increases the resilience of the heel while improving the flexibility of the toe portion compared to when the average diameter or density of the foam cells is uniform. In this case, the high resilience of the heel portion can efficiently convert ground reaction force into energy and assist in pushing off during walking. Meanwhile, increasing the flexibility of the toe portion does not inhibit the flexion movement of the toes, allowing for a natural movement when pushing off.

[0038] The distribution of the average diameter or density of the foam cells may also be set in the opposite direction to that described above. That is, the average diameter or density of the foam cells in the front portion 11 may be smaller than that in the rear portion 13. This configuration increases the resilience of the toe area, increasing the propulsive force when pushing off, while the flexibility of the heel area allows for more effective absorption of impact when landing. As a result, both resilience and shock absorption performance can be achieved during running and other exercise.

[0039] Furthermore, it may be provided in the following aspects.

[0040] (1) An insole placed inside footwear, comprising a front portion of a first thickness, a rear portion of a second thickness that is thicker than the first thickness, and a central portion that changes from the second thickness to the first thickness, and also comprising a receiving portion that stops the foot from sliding forward.

[0041] According to this aspect, it is possible to improve the style, design and comfort of the footwear in a well-balanced manner.

[0042] (2) The insole described in (1) above, wherein the first thickness is 5 mm or less and the second thickness is 12 mm or more.

[0043] According to this aspect, it is possible to make the wearer appear taller while suppressing the bulge in the front of the footwear.

[0044] (3) In the insole described in (2) above, the receiving portion is a portion that curves upward at the tip side of the front portion and curves to a position that is 7 mm or more away from the contact surface where the insole is placed.

[0045] According to this aspect, it is possible to prevent the foot from slipping forward.

[0046] (4) The insole according to any one of (1) to (3) above, wherein the polyurethane content of the insole is 98% or more and 98.5% or less.

[0047] According to this aspect, deterioration of the insole can be suppressed.

[0048] (5) The insole according to (4) above, wherein the foaming agent content of the insole is 0.005% or more and 0.006% or less, and the impact transmission is reduced by 60% or more in terms of the DIN standard ratio.

[0049] According to this aspect, shock can be absorbed and comfort can be improved.

[0050] (6) In the insole described in (5) above, the receiving portion is the front half of the portion in the center of the rear portion that is pushed and bent by the heel.

[0051] According to this aspect, it is possible to prevent the heel from slipping forward.

[0052] (7) Footwear comprising the insole according to any one of (1) to (6) above and a footwear body on which the insole is placed.

[0053] According to this aspect, it is possible to improve the style, design and comfort of the footwear in a well-balanced manner. Of course, this is not the case. Furthermore, the above-described embodiments and modifications may be combined in any desired manner.

[0054] As described above, various embodiments of the present invention have been described, but these are presented as examples and do not limit the scope of the invention in any way. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Such embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as set forth in the claims. [Explanation of symbols]

[0055] 1: Footwear 2: Footwear itself 3: Outsole 4: Upper 5: Shoelaces 6: Heel tab 7: Middle bottom surface 10: Insole 11: Front part 12: Central part 13: Rear part 14: Bottom 21: 1st receiving part 22:Second receiving part 23: Flexure 111: Tip 131: Rear end

Claims

1. An insole placed inside footwear, a front portion of a first thickness; a rear portion having a second thickness greater than the first thickness; a central portion that transitions from the second thickness to the first thickness; It has a receiving part that stops the foot from sliding forward, the first thickness is 5 mm or less; the second thickness is 12 mm or more; The insole has a polyurethane content of 98% or more and 98.5% or less, a foaming agent content of 0.005% or more and 0.006% or less, and reduces shock transmission by 60% or more in accordance with the DIN standard. insole.

2. The insole according to claim 1, The receiving portion is a portion that is warped upward on the tip side of the front portion, and is warped to a position that is 7 mm or more away from the ground surface on which the insole is grounded. insole.

3. The insole according to claim 1, The receiving portion is a front half portion of a portion of the center of the rear portion that is pushed and bent by the heel, insole.

4. Footwear, An insole according to any one of claims 1 to 3, a footwear body with the insole installed; Footwear comprising:

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