Functional insole for preventing forward head posture and falls

Abstract

In a shoe to which a functional insole is applied, according to the present invention, an air cell that expands and contracts according to pressure presses specific parts of the toes or sole with uniform pressure distribution over a wide area and, particularly, effectively supports the metatarsal bones of the toes, and thus can improve a wearing comfort and acupressure effects. Therefore, impact that occurs during walking can be effectively alleviated, and foot deformities or incorrect walking habits can also be prevented.

Description

Functional insoles that help prevent turtle neck and falls

[0001] The present invention relates to a functional insole that helps prevent turtle neck and falls, and more specifically, to a functional insole that helps prevent turtle neck and falls by applying pressure over a wide area with an even pressure distribution to the entire sole of the foot including the arch, and in particular, effectively supporting the metatarsal and interdigital nerve areas of the toes, thereby alleviating gait abnormalities caused by turtle neck and enhancing wearing comfort and acupressure effects.

[0002] Shoes were traditionally a simple product that protected the feet during movement, but now shoes with various functions and unique designs are available.

[0003] The rear axle of the sole of these shoes was formed almost perpendicular to the ground, which put a lot of load and pressure on the feet when walking, causing the feet to tire easily.

[0004] The components of the foot form a basic fixed structure to enable the foot to perform its functions well in both the standing and moving states, and form several standard shapes and structures through the different combinations among them in each state.

[0005] The foot's shape during walking varies depending on the stage of the gait process, and the gait process can be broadly categorized into four stages based on the foot's shape during walking. Based on the movement, the four stages of walking are heel strike, full contact, heel lift, and forefoot push-off. The foot moves through these four stages, performing a cyclical, repeating walking motion.

[0006] First, in the first stage of walking, heel strike, the foot performing normal walking forms dorsiflexion when the heel touches the ground, and in the second stage of walking, full strike, the foot performing normal walking forms plantarflexion, in which the entire foot touches the ground and the ankle extends.

[0007] And in the third stage, heel lift, the ankle straightens further, and as plantar flexion deepens, the joint where the head of the metatarsal and the coxae, which form the first joint of the toes, are connected bend upwards. In the fourth stage, forefoot push-off, the toes plantar flex, and the metatarsals and coxae, which were bent and formed an angle with each other in the third stage, straighten, causing the toes to push the ground backwards. Afterwards, in preparation for the transition to the first stage of walking, dorsiflexion is formed and the foot leaves the ground.

[0008] In order for walking to proceed smoothly at each of these stages, the components of the foot form several standard shapes in relation to each other, and if these shapes are not properly implemented for any reason, walking becomes inefficient. On the one hand, excessive pressure or force may be applied to each part of the foot, which may cause damage or deformity. On the other hand, there is a problem that the function of the foot is weakened along with deformity of the foot because the necessary parts of the foot are not sufficiently used.

[0009] The present invention has been devised to solve the above problems, and specifically, it aims to provide a functional insole that helps prevent turtle neck and falls by applying pressure over a wide area with even pressure distribution to the entire sole including the arch, effectively supporting the metatarsal and interdigital nerve areas of the toes, thereby alleviating gait abnormalities caused by turtle neck, and enhancing wearing comfort and acupressure effects.

[0010] The present invention relates to a functional insole that helps prevent turtle neck and falls.

[0011] One aspect of the present invention relates to a functional insole structure that helps prevent turtle neck and falls, comprising: a base material; an upper airbag formed on an exposed surface of the base material corresponding to a metatarsal of the wearer and supporting the toes of the wearer; a lower airbag formed on an exposed surface of the base material corresponding to a calcaneus of the wearer and supporting the heel of the wearer; and an arch airbag formed on a portion corresponding to an arch of the sole of the wearer and connected to the upper airbag, the lower airbag, or both the upper airbag and the lower airbag through a channel; wherein the airbag is pressurized and inflated by the wearer's walking to support the wearer's foot.

[0012] In the present invention, the upper airbag or the lower airbag further includes an elastic pad on the upper surface, and specifically, the elastic pad is characterized by being a polyurethane foam obtained by catalytically reacting a mixture containing 20 to 60 parts by weight of an isocyanate compound with respect to 100 parts by weight of a polyol composition containing any one of a regenerated polyol, a bio-polyol, or a mixture thereof.

[0013] In addition, one or more airbags selected from the upper airbag, lower airbag, and arch airbag are manufactured from thermoplastic polyurethane fabric, and the arch airbag includes a primary arch airbag formed in a portion corresponding to the arch of the wearer's sole; and a secondary arch airbag provided above the primary arch airbag so as to be mutually connected.

[0014] Shoes featuring functional insoles according to the present invention utilize airbags that expand and contract based on pressure, evenly distributing pressure across a wide area on specific areas of the toes or soles. This effectively supports the metatarsals and interdigital nerves of the toes, enhancing comfort and acupressure. This effectively mitigates shock during walking and prevents poor walking habits, such as foot deformities and forward head posture.

[0015] Figure 1 illustrates the bones of a typical human foot.

[0016] FIG. 2 illustrates a functional insole manufactured according to one embodiment of the present invention.

[0017] Figure 3 is a cross-sectional view of a functional insole manufactured according to one embodiment of the present invention.

[0018] FIG. 4 is a cross-sectional view illustrating air flow in an airbag manufactured according to one embodiment of the present invention.

[0019] The following specific examples will be used to describe in detail the functional insoles according to the present invention that help prevent turtle neck and falls. The specific examples presented below are provided as examples to ensure that those skilled in the art can fully grasp the spirit of the present invention.

[0020] Accordingly, the present invention is not limited to the specific examples presented below and may be embodied in other forms. The specific examples presented below are only described to clarify the idea of ​​the present invention, and the present invention is not limited thereto.

[0021] In this case, if there is no other definition in the technical and scientific terms used, they have the meaning commonly understood by a person of ordinary skill in the technical field to which this invention belongs, and in the following description, descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention are omitted.

[0022] Additionally, the singular forms used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0023] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of the present invention. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

[0024] First, Figure 1 illustrates the structure of the foot bones when viewed from the side. The foot includes the phalanges (1) that form the toes in the longitudinal direction, the metatarsals (2), cuneiform (3), and navicular (4) that are connected at the ends of the phalanges to form the instep, the talus (5) that is connected at the ends of the navicular to form the ankle, and the calcaneus (6) that is connected to the talus to form the heel.

[0025] Modern people's poor walking habits and the prolonged wearing of shoes like high heels, which can deform the feet, can lead to toe deformities. A common example of a toe deformity is hallux valgus, which causes the big toe to turn outward. Hallux valgus is caused by ill-fitting shoes, pointed toes, or high heels. When hallux valgus occurs, the protruding part of the toe rubs against the shoe, causing pain. In severe cases, it can even cause a deformity of the little toe, making it impossible to wear regular shoes. The foot experiences approximately 16 tons of pressure for every kilometer it walks, requiring weight to be evenly distributed across the entire sole. However, when wearing shoes with narrow, high forefoot areas or being obese, weight shifts forward, causing the big toe to bend and the little toe to protrude, a condition called bunion, worsening the overall foot deformity. As the big toe deformity progresses, the big toe and second toe may overlap or the joint may become dislocated.

[0026] Additionally, if the deformation of the foot continues, the habit of walking to avoid feeling pain may develop naturally, which may lead to incorrect walking posture and problems not only in the toes but also in the ankles, instep, and spine.

[0027] The present invention was devised to solve the above problems, and includes an upper airbag formed in a portion of an exposed surface of a base material, which is an insole, corresponding to the metatarsal bone, which is the toe part of the wearer, to support the toes of the wearer, and a lower airbag formed in a portion of the exposed surface of the base material, corresponding to the calcaneus bone, to support the heel of the wearer, and at the same time, when walking, the airbags expand to naturally support the toes or heels, thereby protecting the feet of the wearer, and at the same time reducing the external force applied to the toes, thereby suppressing deformation of the feet and pain resulting therefrom, thereby completing the present invention.

[0028] The functional insole according to the present invention, which helps prevent turtle neck and falls, may include a base material (100), as shown in FIGS. 2 and 3; an upper airbag (200) formed on an exposed surface of the base material corresponding to the wearer's metatarsal bone to support the wearer's toes; a lower airbag (300) formed on an exposed surface of the base material corresponding to the wearer's calcaneus to support the wearer's heel; and an arch airbag (400) formed on a portion corresponding to the wearer's sole arch (7) and connected to the upper airbag, the lower airbag, or both the upper airbag and the lower airbag through a path (500).

[0029] In the present invention, the above-mentioned substrate (100) is a part that forms the main body of the insole and is provided on the inside of the shoe to support the sole and toes.

[0030] Specifically, the above-mentioned material is basically formed to fit the shape of the sole of the wearer's foot as shown in Fig. 3, and may be provided with an upper window (110) and a lower window (120) formed at the bottom of the upper window. At this time, an upper opening (111), a lower opening (112), etc. may be formed in the upper window so that an airbag, which will be described later, can be exposed to the outside of the material.

[0031] The lower sole (120) is positioned on the sole of the shoe and may be made of a non-woven material. In addition, in the case of the lower sole, the upper sole may be bonded to the lower sole using an adhesive or the like so that the airbag located between the lower sole and the upper sole does not move according to the movement of the foot when the insole according to the present invention is applied to the shoe. Separately, it is preferable to increase the surface roughness of the part of the lower sole where the airbag is positioned to increase friction.

[0032] The upper window (110) is located above the lower window, and can be attached to the lower window using adhesive or sewing, etc., so as to come into contact with the user's foot.

[0033] The upper window is not limited to a specific material and may be made of non-woven fabric or mesh. These materials maximize the breathability of the material, allowing sweat and odors to be easily removed.

[0034] In addition, the upper window may further be formed with an upper opening (111) and a lower opening (112) so that one side of the airbag described above can be exposed toward the sole of the wearer's foot. The upper opening or the lower opening may be formed in the upper window corresponding to the corresponding portion so that the upper airbag and the lower airbag can be exposed to the corresponding portion of the wearer's metatarsal and calcaneus, respectively.

[0035] This allows each airbag to expand when a downward load (toward the ground) is applied to each airbag, supporting the corresponding part of the sole. Furthermore, the shoe's insole can be prevented from spreading outward even under load, and by directing the airbag's expansion in one direction, it can effectively compress the toes, sole, and heel.

[0036] Here, an exposure hole (not shown) may be provided separately from the above-mentioned opening, through which the arch airbag can be partially exposed. The exposure hole has the advantage of stimulating consumers' desire to purchase, as it allows them to visually confirm the presence of the airbag.

[0037] In the present invention, the airbag is fixed to the lower window of the substrate, and the exposed surface corresponds to the sole of the wearer's foot through an opening formed in the upper window, and can be pressurized and inflated by the wearer's walking to support the wearer's foot.

[0038] Specifically, the airbag may include an upper airbag (200) formed in a portion of the exposed surface of the substrate corresponding to the wearer's metatarsal bone to support the wearer's toes, a lower airbag (300) formed in a portion of the exposed surface of the substrate corresponding to the wearer's calcaneus to support the wearer's heel, and an arch airbag (400) formed in a portion corresponding to the wearer's sole arch and connected to the upper airbag, the lower airbag, or both the upper airbag and the lower airbag through a path (500).

[0039] The above-described arch airbag (400) may include a primary arch airbag (410) formed in a portion corresponding to the arch of the wearer's sole; and a secondary arch airbag (420) provided above the primary arch airbag so as to be mutually connected. In addition, the arch airbag, upper airbag, and lower airbag are connected to each other so that internal air can flow to other airbags by pressure.

[0040] Through this, when a load is applied to the upper or lower airbag, the air inside the upper or lower airbag can move to the primary arch airbag and then ultimately flow into the secondary arch airbag. The arch airbag into which air has flowed can naturally expand and compress the arch area of ​​the sole of the foot.

[0041] That is, when the height is formed high with a single arch airbag, the pressure tends to be concentrated in the central part more than other parts when the arch airbag is inflated, resulting in a greater inflating tendency. However, by forming an arch airbag with a double-layered structure as described above, the pressure is evenly distributed and there is an advantage in that the support effect on the sole of the foot is increased.

[0042] The above-mentioned primary arch airbag and secondary arch airbag have the same shape and are laminated and connected. At this time, since the primary arch airbag and secondary arch airbag have the same shape, the primary arch airbag supports the secondary arch airbag from below, so that more uniform pressure can be transmitted.

[0043] This air movement can cause other airbags to inflate whenever pressure is applied to the upper airbag, lower airbag, or arch airbag. For example, as shown in Fig. 4, when the arch airbag is compressed and deflated, the air within that airbag naturally flows into the upper or lower airbag. As the air-filled airbag expands, it supports the corresponding foot area.

[0044] In other words, the upper airbag can naturally support the toes by expanding or contracting due to its position, while the lower airbag can support the heel. This prevents deformation of the toes or calluses on the heel due to external forces or poor walking habits, while also providing the wearer with a more comfortable walking experience.

[0045] The upper airbag may further be provided with toe grooves, allowing five toes to be positioned as needed. These toe grooves help maintain the position of the toes, and can also function to acupressure the acupoints located in the toes by compressing them upon expansion.

[0046] To achieve this, it is desirable to minimize discomfort during wear by molding the shape of the toe groove to match the shape of the wearer's foot. This can be accomplished by molding the shape of the wearer's foot, or by modeling the shape of the wearer's foot using a 3D scanner or similar tool, which can then be shaped using a 3D printer or similar tool.

[0047] Furthermore, the upper airbag, lower airbag, or arch airbag can be customized to the user's specific needs by varying the amount of air injected or the size of the internal space. For example, the airbag can be classified into large, medium, and small sizes based on the maximum amount of air it can inject. Considering the wearer's weight, the amount of air injected can be increased for heavier individuals. Furthermore, the area of ​​contact between the airbag and the sole of the wearer's foot can be varied based on foot size, allowing for a shoe that suits all age groups.

[0048] The material of the upper airbag, lower airbag, or arch airbag is not limited. For example, the airbags may be manufactured from a fabric containing a polymer resin, and may be completely sealed while retaining some air, allowing airflow only between the airbags.

[0049] Specifically, the airbag can be manufactured from a thermoplastic polyurethane fabric. The thermoplastic polyurethane is a segmented block copolymer composed of a hard segment, which is a rigid molecular chain, and a soft segment, which is a flexible molecular chain. Each segment undergoes a micro-phase separation phenomenon due to thermodynamic incompatibility with each other to form a hard domain and a soft domain, respectively. The hard domains are connected by hydrogen bonds between molecules and act as physical cross-linking points of the soft domains, so that the material has high resilience, excellent compressive strain, and excellent resistance to impact, wear, tear, adverse weather conditions, and hydrocarbons.

[0050] The thermoplastic urethane elastomer exhibits higher heat resistance and superior mechanical properties as the phase separation between the soft and hard segments improves. This phase separation can be influenced by the type of polyisocyanate, the type of chain extender, and the mixing ratio of polyol, polyisocyanate, and chain extender.

[0051] That is, the higher the hard segment content (18 parts by weight or more), the higher the heat resistance and ease of phase separation, and the more densely the polymer chains can be formed, so that the polyol can be comprised of 50 to 90 wt%, the polyisocyanate of 10 to 20 wt%, and the benzothiazole-based chain extender of 0.1 to 10 wt%.

[0052] Polyol refers to a compound having two or more hydroxyl groups (-OH) in the molecule, and is a substance obtained by reacting an initiator such as a polyfunctional alcohol or aromatic amine having two or more hydroxyl groups (-OH) or amine groups (-NH2) in the molecule with propylene oxide (PO) or ethylene oxide (EO) under appropriate conditions. Low molecular weight polyols are used as crosslinking agents and reactive flame retardants, and high molecular weight polyols are used in the production of polyurethane by reacting with isocinates. The high molecular weight polyols include polyester polyol, polycarbonate polyol, polyether polyol, etc.

[0053] In the present invention, the polyol may be polycarbonate polyol, polyester polyol, or a mixture thereof.

[0054] When a mixture of polycarbonate polyol and polyester polyol is used, polycarbonate polyol is a compound with excellent heat resistance, hydrolysis resistance, durability, wear resistance, mechanical properties, etc., and can play a role in complementing the physical properties such as heat resistance, hydrolysis resistance, wear resistance, and mechanical properties, which are shortcomings of polyester polyol.

[0055] The number average molecular weight of the polycarbonate polyol may be 500 to 4000, preferably 1000 to 2000. If the number average molecular weight of the polycarbonate polyol is less than 500, the content of the hard segment (polyisocyanate and chain extender) of the final polyurethane resin becomes very high, resulting in high hardness, making it unsuitable for use as a shoe insole material. If the number average molecular weight of the polycarbonate polyol exceeds 4,000, the content of the hard segment of the final polyurethane resin becomes too low, resulting in softness, very low hardness, and low mechanical strength, making it unsuitable for use as an insole material.

[0056] The above polycarbonate polyol may be polycarbonate diol or polyhexamethylene carbonate diol.

[0057] The above polyester polyol may be polycaprolactone diol, which is a type of polyol in which ester groups (Ester, -COO-) are repeatedly bonded to the molecular structure.

[0058] The above polyester polyol is obtained through a condensation reaction of a dibasic acid and a dihydric alcohol. The dihydric acid may be used alone or in a mixture of two or more of adipic acid, azelaic acid, and succinic acid, but it is preferable to use adipic acid alone. The dihydric alcohol may be used alone or in a mixture of two or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 2-methylpropanediol, 1,4-cyclohexanedimethanol, and bisphenol A, but it is preferable to use 1,4-butanediol and 1,6-hexanediol alone or in a mixture.

[0059] The number average molecular weight of the polyester polyol may be 500 to 4000, more preferably 1000 to 3000. If the number average molecular weight of the polyester polyol is less than 500, the polyurethane resin may become hard and may not have good flexibility, and if the number average molecular weight of the polyester polyol exceeds 4,000, there is a concern that the elongation of the polyurethane resin may become too high and the tensile strength may relatively decrease.

[0060] In the present invention, the polycarprolactonediol is a polyester polyol having high crystallinity and excellent physical properties, and can be obtained by ring-opening addition polymerization of lactone with an initiator such as a low molecular weight diol.

[0061] It is preferable that the composition ratio of the mixture of the above polycarbonate polyol and polyester polyol is 7:3. This is more preferable because it can properly complement the physical properties of polyester polyol, such as heat resistance, hydrolysis resistance, wear resistance, and mechanical properties.

[0062] In the present invention, polyisocyanate is a compound containing three or more -NCO groups, is tear-free and highly reactive, and reacts with compounds containing active hydrogen to form various bonds. In particular, when the structure of polyisocyanate is linear, phase separation is easy and polymer chains can be formed more densely.

[0063] The above polyisocyanate may be diisocyanate, and the diisocyanate may be aliphatic, alicyclic, or aromatic. However, in order to satisfy various physical properties such as bending resistance, yellowing resistance, and water dispersion stability, aliphatic and alicyclic diisocyanates may be used alone or in combination of two or more. Examples thereof include isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (1,6-HDI), 4,4'-methylenebiscyclohexane diisocyanate (4-4'-H12MDI), 1,3-xylene diisocyanate (1,3-XDI), and / or 1,3-tetramethylxylene diisocyanate (1,3-TMXDI), paraphenylenediisocyanate (p-phenylenediisocyanate, PPDI), etc.

[0064] The above chain extender or initiator refers to a bifunctional substance such as a diol or diamine, which is a reactive single molecule used to strengthen polymerization or intermolecular bonds. A polyvalent initiator is a compound having two or more active hydrogen atoms with which an alkylene oxide can react, and may be divalent to hexavalent, preferably divalent to trivalent, such as a polyhydric alcohol or polyamine.

[0065] The above polyhydric alcohol may include dihydric 1,4-butane diol (BDO), 1,6-hexanediol, etc., and the polyamine may include trimethylene glycol dipara-aminobenzoate (TGDAB) as an aromatic primary amine extender, and 6,6-oxy bis-2-aminobenzothiazole (6,6(-oxy bis(2-aminobenzothiazole), ABT) as a benzothiazole series.

[0066] The above benzothiazole series is one of the polybenzazole series, and the polybenzazole series includes polybenzobisthiazoles (PBTs), polybenzobisoxazoles (PBOs), and polybenzimidazoles (PBIs).

[0067] For the production of high-temperature polyurethanes, amine-based initiators, rather than polyalcohol-based ones, exhibit superior thermal stability compared to alcohol-based or other types of initiators. This is because their amine functionality enhances mechanical strength through crosslinking during polyurethane resin synthesis.

[0068] However, thermoplastic polyurethane has a high hygroscopicity due to its molecular structure. When exposed to air, it rapidly absorbs moisture, resulting in a decline in mechanical strength and physical properties. This problem arises because shoes are often exposed to water, and the wearer's sweat often maintains high humidity levels inside the shoe, potentially limiting the long-term maintenance of the airbag's properties.

[0069] Therefore, the composition for airbag fabric according to the present invention can secure antibacterial properties while also lowering the hygroscopicity of the composition and improving the mechanical properties by further including a block copolymer and a multifunctional polymer resin together with the above-described high heat-resistant polyurethane.

[0070] The above block copolymer is basically a copolymer of polyamide and polyether, and because it contains polyamide blocks, it basically has excellent elasticity, and at the same time, the chemical properties such as hydrophobicity, wear resistance, and chemical resistance can be greatly improved by the polyether blocks.

[0071] The above polyamide can basically be manufactured by polymerization of caprolactam and dicarboxylic acid, and the number of carbons between the amine groups of the lactam or the number of carbons between the carboxyl groups of the dicarboxylic acid is not limited in the present invention.

[0072] For example, the lactam may be selected from 2-pyrrolidone, ε-caprolactam, oenante lactam, caprylactam, peragolactam, caprinolactam, 11-undecane lactam, lauryllactam, and mixtures thereof, and the carboxylic acid may be selected from 4-aminobutanoic acid, 6-aminohexanoic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and mixtures thereof. In addition, the polyamide may be produced in the form of an oligomer and may have a number average molecular weight of 500 to 5000.

[0073] The above polyether may be selected from polyethylene glycol (PEO), polypropylene glycol (PPG), and polytetramethylene glycol (PTMG), and may have a number average molecular weight of 650 to 5,000.

[0074] The above polyamide and polyether are not limited in composition ratio, but are preferably polymerized in a weight ratio of 5 to 7:3 to 5, respectively. If the composition ratio exceeds the above range, moisture resistance may not be properly expressed or mechanical properties such as impact strength may decrease.

[0075] The above block copolymer is not limited by its manufacturing method. For example, polyamide oligomers and polyether oligomers each have an amine group and a maleimide group at both ends, and can be polymerized through coupling bonds using addition reactions. This coupling bond can be produced by reacting at a temperature of 150 to 250°C for 1 to 6 hours under nitrogen or an inert atmosphere.

[0076] The above block copolymer may be included in an amount of 10 to 30 parts by weight relative to 100 parts by weight of the thermoplastic polyurethane. If the amount of the block copolymer added is less than the above range, the effect of supplementing the mechanical properties after moisture absorption described above is insufficient, and if it exceeds the above range, the mechanical properties of the composition may deteriorate.

[0077] Since the above-mentioned multifunctional polymer resin has a number of functional groups, it plays a role in improving the mechanical and chemical properties of the fabric by forming bonds such as hydrogen bonds with the functional groups of the TPU or block copolymer described above.

[0078] Examples of the above multifunctional polymers include polymers containing functional groups such as amine groups or nitrile groups, and specifically, polyacrylonitrile amidoxime, amidooxymate poly(N'N-dipropionitrile acrylamide), and poly(amido)amine-based 3-styrene divinylbenzene. These may be used alone or in combination of two or more.

[0079] The above multifunctional polymer may be included in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the thermoplastic polyurethane. If the content of the multifunctional polymer is below the above range, the above-described effects are not fully realized, and if it exceeds the above range, the viscosity of the composition may increase, resulting in a significant decrease in formability and mechanical properties.

[0080] Additionally, the upper airbag or lower airbag may further include an elastic pad on the upper surface to further improve frictional strength and mechanical properties.

[0081] The above elastic pad is basically formed of polyurethane foam, and can be obtained by catalytically reacting a mixture containing 20 to 60 parts by weight of an isocyanate compound with respect to 100 parts by weight of a polyol composition containing any one of a recycled polyol, a bio-polyol, or a mixture thereof.

[0082] In the present invention, among the polyol compositions, it is preferable to use a polymer having a number average molecular weight of 2,000 to 8,000 as a multi-polymer dispersion polyol in the form of a complex emulsion manufactured through depolymerization of a soft polyurethane foam generated after use of the soft polyurethane foam or during processing of the soft polyurethane foam.

[0083] The above bio-polyol is preferably a polyol having a number average molecular weight of 2000 to 6000 and a biomass content of 20 to 98 wt%, made of one or more natural derivatives selected from cashew nut shells, soybean oil, corn, palm, or pajamas.

[0084] It is preferable to use the isocyanate used in the above-described TPU as the above-described isocyanate compound, and more preferably, it is preferable to use methylene diphenyl diisocyanate.

[0085] Shoes with a functional insole according to the present invention can apply pressure to a specific part of the toes or sole of the foot over a wide area with an even pressure distribution using an air bag that expands and contracts according to pressure, and in particular, can effectively support the metatarsal bones of the toes, thereby enhancing the wearing comfort and acupressure effect.

[0086] This effectively mitigates the impact of walking and prevents foot deformation and poor walking habits. In particular, the functional insole according to the present invention, when worn by people with forward head posture, improves walking straightness and consistency, provides a sense of stability, and expands the range of motion.

[0087] In addition, since the speed at which the foot lands (Foot speed Norm at minimal toe clearance) can be lowered when wearing the functional insole according to the present invention, the angle at which the forefoot leaves the ground and the angle at which the heel touches the ground can be reduced, allowing comfortable and stable walking.

[0088] Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the following examples are merely illustrative examples for explaining preferred embodiments of the present invention, and the present invention is not limited by the following examples.

[0089] The physical properties of the specimens manufactured through examples and comparative examples were measured as follows.

[0090] (mechanical properties)

[0091] The specimens were processed in film form according to ASTM D-638. Afterwards, using an Ultimate Tensile Machine (UTM) machine (Model 3343, INSTRON), one end of the specimen was fixed and the other end was pulled at a speed of 300 mm / min, and the tensile strength according to the extent of stretching of the thermoplastic polyurethane film was measured. The mechanical properties were measured at 100% elongation, 300% elongation, 500% elongation, tensile strength at break, and elongation, and the tests were conducted after 48 hours under conditions of relative humidity of 15 ± 2.5% and 80 ± 2.5%, respectively.

[0092]

[0093] (Example 1)

[0094] To determine the properties of thermoplastic polyurethane used as fabric for upper airbags, etc., polycaprolactone polyol (Mw 1,000) and paraphenylenediisocyanate were first synthesized to produce a prepolymer, and then butanediol was added to produce thermoplastic polyurethane. The produced polyurethane was molded into a 200㎛-thick film for airbag fabric.

[0095] (Example 2)

[0096] A specimen was manufactured in the same manner as in Example 1 above, except that 20 parts by weight of polyamide (Mw 250, Ny6.6) was additionally mixed with 100 parts by weight of polyurethane during film molding.

[0097] (Example 3)

[0098] A specimen was manufactured in the same manner as in Example 1 above, except that 20 parts by weight of polyether (Mw 300) was added to 100 parts by weight of polyurethane during film forming.

[0099] (Example 4)

[0100] A specimen was manufactured in the same manner as in Example 1, except that 20 parts by weight of a block copolymer polymerized with the polyamide of Example 2 and the polyether of Example 3 in a weight ratio of 8:2 was further mixed during film forming.

[0101] (Example 5)

[0102] A specimen was prepared in the same manner as in Example 4 above, except that 0.5 weight part of amidooxymate poly(N'N-dipropionitrile acrylamide) was added during film forming.

[0103] (Example 6)

[0104] A specimen was prepared in the same manner as in Example 4 above, except that 3 parts by weight of amidooxymate poly(N'N-dipropionitrile acrylamide) was added during film forming.

[0105] Tensile strength (MPa) Breaking 100% 300% 500% Breaking strength (MPa) Elongation (%) Drying Moisture absorption Drying Moisture absorption Drying Moisture absorption Drying Moisture absorption Example 13.70 1.27 5.81 3.58 22.08 19.54 27.68 22.47 54 35 11 Example 24.5 23.0 17.45 4.96 25.10 20.96 31.54 26.30 58 9 520 Example 34.67 3.09 7.84 5.04 25.46 21.07 32.21 26.87 59 35 19 Example 45.933.6811.248.5327.5522.6337.8931.14621553 Example 57.516.9813.9312.2734.8432.6145.5842.06667643 Example 67.897.8814.5213.4835.9333.0740.0239.54550527

[0106] As shown in Table 1 above, the shoe sole manufactured according to the present invention can easily repeat expansion and contraction even in a humid shoe environment due to the excellent physical properties of the airbag fabric provided therein. In particular, Example 4, which further includes a block copolymer together with thermoplastic polyurethane, and Example 5, which further adds a multifunctional resin, exhibit the best mechanical properties, and in particular, it can be seen that the mechanical properties do not deteriorate significantly even after moisture absorption.

[0107] The present invention described above is not limited to the above-described embodiments, and it will be apparent to a person skilled in the art to which the present invention pertains that various substitutions, modifications, and changes are possible within a scope that does not depart from the technical spirit of the present invention.

Claims

1. In terms of functional insole structure that helps prevent turtle neck and falls, write; An upper airbag formed in a portion of the exposed surface of the above-mentioned description corresponding to the wearer's metatarsal bone to support the wearer's toes; A lower airbag formed in a portion of the exposed surface of the above description corresponding to the wearer's calcaneus to support the wearer's heel; and An arch airbag formed in a portion corresponding to the arch of the wearer's foot and connected to the upper airbag, the lower airbag, or both the upper airbag and the lower airbag through a path; A functional insole that helps prevent turtle neck and falls, characterized in that it includes an airbag that is pressurized and inflated by the wearer's walking to support the wearer's feet.

2. In paragraph 1, A functional insole that helps prevent turtle neck and falls, characterized in that the upper airbag or lower airbag further includes an elastic pad on the upper surface.

3. In paragraph 2, The above elastic pad is a functional insole that helps prevent turtle neck and falls, characterized in that it is a polyurethane foam obtained by catalytically reacting a mixture containing 20 to 60 parts by weight of an isocyanate compound with respect to 100 parts by weight of a polyol composition containing any one of regenerated polyol, bio-polyol, or a mixture thereof.

4. In paragraph 1, A functional insole that helps prevent turtle neck and falls, characterized in that one or more airbags selected from the upper airbag, lower airbag, and arch airbag are made of thermoplastic polyurethane fabric.

5. In paragraph 1, The above arch airbag, A primary arch airbag formed in a portion corresponding to the arch of the wearer's foot; and A secondary arch airbag provided in communication with each other above the primary arch airbag; A functional insole that helps prevent turtle neck and falls, characterized by including:

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