Composition for shoe outsole, shoe outsole manufactured using same, and method for manufacturing same

Abstract

Disclosed are: a composition for a shoe outsole having improved tensile strength, abrasion resistance, yellowing resistance, transparency, non-slip properties, and the like compared to conventional shoe outsoles; a shoe outsole manufactured using same; and a method for manufacturing same. The composition for a shoe outsole comprises 91-97 wt% of a polyurethane-based thermoplastic elastomer and 3-9 wt% of a functional composition, wherein the functional composition includes a butadiene rubber.

Description

Composition for shoe outer sole, shoe outer sole manufactured using the same, and method for manufacturing the same

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0118174, filed September 6, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a composition for a shoe outer sole, a shoe outer sole manufactured using the same, and a method for manufacturing the same, and more particularly, to a composition for a shoe outer sole capable of improving tensile strength, wear resistance, yellowing resistance, transparency, and non-slip properties, etc., compared to a conventional shoe outer sole, a shoe outer sole manufactured using the same, and a method for manufacturing the same.

[0003] Typically, a shoe sole is made up of the upper, which wraps around the foot; the outer sole, which is the part that comes into contact with the ground and is made of a material with strong wear resistance and grip; and the midsole, which is located between the upper and the outer sole and absorbs the shock generated when the outer sole comes into contact with the ground. Among these, the midsole is mainly made of a lightweight and elastic material such as ethylene vinyl acetate (EVA) sponge, and the outer sole is manufactured by mixing natural rubber or synthetic rubber with reinforcing agents such as silica and crosslinking agents such as sulfur, placing it in a mold, and then pressurizing and crosslinking it.

[0004] In particular, the outer sole requires excellent tensile strength and durability in addition to the abrasion resistance and grip (non-slip characteristics) described above. In addition, the use of transparent and white outer soles has recently increased, and these require additional characteristics such as yellowing resistance and transparency. Furthermore, considering productivity, the trend is gradually increasing from thermosetting types to thermoplastic types. Although thermoplastic rubber (TPR) is used as a main component in some of these outer sole materials, it has the problem of insufficient mechanical strength and non-slip characteristics. Therefore, thermoplastic polyurethane (TPU) is attracting attention as a material that can replace thermoplastic rubber as an outer sole material, and is currently being developed and used as a material for many shoe products.

[0005] Korean Patent Nos. 10-2092733 and 10-1756083 also utilize thermoplastic polyurethane (TPU) as the primary material for shoe outsoles. Furthermore, they attempt to improve the problems previously identified with shoe outsoles by using butadiene rubber and other additives (antioxidants, UV absorbers, cross-linking agents) to enhance non-slip properties and transparency. However, only the non-slip properties of the shoe outsoles have been improved, while key properties such as tensile strength, abrasion resistance, yellowing resistance, and transparency remain unsatisfactory. Furthermore, further improvement in non-slip properties is needed.

[0006] Therefore, a method is required to improve the main properties of the shoe outsole, such as tensile strength, wear resistance, yellowing resistance, transparency, and non-slip properties.

[0007] [Prior Art Literature]

[0008] [Patent Document]

[0009] (Patent Document 1) Republic of Korea Patent No. 10-2092733

[0010] (Patent Document 2) Republic of Korea Patent No. 10-1756083

[0011] Accordingly, the purpose of the present invention is to provide a composition for a shoe outer sole that can improve tensile strength, wear resistance, yellowing resistance, transparency, and non-slip properties compared to a conventional shoe outer sole, a shoe outer sole manufactured using the same, and a method for manufacturing the same.

[0012] To achieve the above object, the present invention provides a composition for a shoe outer sole, comprising 91 to 97 wt% of a polyurethane-based thermoplastic elastomer and 3 to 9 wt% of a functional composition, wherein the functional composition comprises butadiene rubber.

[0013] In addition, the present invention provides a shoe outsole manufactured using the composition for the shoe outsole.

[0014] In addition, the present invention provides a method for manufacturing a shoe outsole, comprising the steps of: a) preparing a mixture by mixing a functional composition including butadiene rubber and an additive including a crosslinking agent in a kneader at 100 to 120°C for 10 to 20 minutes; b) preparing a composition for a shoe outsole by dynamically crosslinking and reaction extruding a polyurethane thermoplastic elastomer together with the mixture in an extruder or a closed kneader having a barrel temperature of 120 to 180°C; and c) forming a shoe outsole by injection molding or 3D printing the prepared composition for a shoe outsole.

[0015] According to the composition for a shoe outer sole according to the present invention, the shoe outer sole manufactured using the same, and the manufacturing method thereof, the composition has the advantage of being able to improve tensile strength, wear resistance, yellowing resistance, transparency, and non-slip properties, etc., compared to conventional shoe outer soles.

[0016] Hereinafter, the present invention will be described in detail.

[0017] A composition for a shoe outsole according to the present invention comprises 91 to 97 wt% of a polyurethane-based thermoplastic elastomer; and 3 to 9 wt% of a functional composition; wherein the functional composition comprises butadiene rubber.

[0018] As previously explained, the shoe sole is generally composed of the upper that wraps the foot, the outsole that comes into contact with the ground and must have excellent wear resistance, grip (non-slip properties), tensile strength, yellowing resistance, and transparency, and the midsole that is located between the upper and the outsole and absorbs the shock generated when the outsole comes into contact with the ground. Among these, the outsole is manufactured by mixing natural rubber or synthetic rubber with reinforcing agents such as silica and crosslinking agents such as sulfur, putting it into a mold, and then pressurizing and crosslinking it. In particular, although some thermoplastic rubber (TPR) is used as a main component, there are problems in that the mechanical strength and non-slip properties are insufficient. In addition, thermoplastic polyurethane (TPU) is also used as a material for the outer sole along with butadiene rubber and other additives (antioxidants, UV absorbers, cross-linking agents), but only the non-slip properties (or slip resistance) of the shoe outer sole are improved, and the main properties such as tensile strength, wear resistance, yellowing resistance, and transparency are still at an unsatisfactory level.

[0019] Accordingly, the applicant, after repeated research from various angles, invented a composition for a shoe outsole that can improve the main properties of the shoe outsole by including thermoplastic polyurethane (TPU) and other functional compositions.

[0020] First, the polyurethane-based thermoplastic elastomer is an elastomer that not only has excellent wear resistance and mechanical strength, but is also recyclable. In addition, the polyurethane-based thermoplastic elastomer may include at least one of an ester-based polyurethane-based thermoplastic elastomer and an ether-based polyurethane-based thermoplastic elastomer having a hardness of about 85A (asker A) or less, taking into consideration compatibility with the functional composition described below, wear resistance, elasticity, manufacturing cost, etc., and an appropriate hardness of the shoe outsole (meaning a hardness that can be used as a typical shoe outsole, typically 65 to 75A (asker A)).

[0021] While the industry recognizes the appropriate hardness for a typical shoe outsole, as described above, a polyurethane-based thermoplastic elastomer with a hardness matching this has yet to be readily found. However, after extensive research and experimentation, the applicant has developed a polyurethane-based thermoplastic elastomer with a hardness of 65 to 85 A (asker A), and by applying this to the present invention, it has been possible to readily achieve the hardness value required for a shoe outsole.

[0022] For example, the ester-based polyurethane thermoplastic elastomer refers to a polyurethane thermoplastic elastomer containing at least one ester structure (RO-CO-R', where R and R' are each an alkyl group), and the ether-based polyurethane thermoplastic elastomer refers to a polyurethane thermoplastic elastomer containing at least one ether structure (C-O-C).

[0023] The content of the polyurethane-based thermoplastic elastomer is, as described above, 91 to 97 wt%, preferably 92 to 97 wt%, and more preferably 92 to 96 wt%. If the content of the polyurethane-based thermoplastic elastomer is less than 91 wt%, there is a concern that physical properties such as tensile strength and wear resistance may deteriorate, and if it exceeds 97 wt%, the content of the remaining components (functional composition, etc.) constituting the composition for the shoe outsole may relatively decrease, resulting in a problem of debris phenomenon occurring.

[0024] In addition, it is preferable that the polyurethane-based thermoplastic elastomer have a melting point of 180°C or lower. If the melting point of the polyurethane-based thermoplastic elastomer exceeds 180°C, the mixing time becomes longer and the mixing temperature becomes higher, which may cause yellowing.

[0025] Next, the functional composition is intended to further improve the tensile strength and abrasion resistance of the shoe outsole, as well as the yellowing resistance, and to impart transparency. The functional composition basically includes butadiene rubber. In addition, the functional composition may further include at least one selected from the group consisting of styrene butadiene rubber, ethylene propylene rubber, and ethylene vinyl acetate for the purpose of improving the non-slip properties, tensile strength, abrasion resistance, yellowing resistance, and transparency of the shoe outsole. In addition, the functional composition of the present invention or the composition for the shoe outsole preferably does not include silicone rubber in order to achieve the purpose of the present invention.

[0026] If the functional composition further includes at least one selected from the group consisting of styrene butadiene rubber, ethylene propylene rubber, and ethylene vinyl acetate (i.e., the second functional component) in addition to butadiene rubber (i.e., the first functional component), the first functional component may be included in an amount of 1 to 7 wt%, preferably 2 to 6 wt%, based on the total weight of the shoe outer sole composition, and the second functional component may be included in an amount of 1 to 5 wt%, preferably 1 to 4 wt%, based on the total weight of the shoe outer sole composition.

[0027] The content of the functional composition may be 3 to 9 wt% as described above, preferably 3 to 8 wt%, and more preferably 4 to 8 wt%. If the content of the functional composition is less than 3 wt%, the non-slip properties of the shoe outsole may deteriorate and a debris phenomenon may occur. In addition, if the content of the functional composition exceeds 9 wt%, the content of the polyurethane thermoplastic elastomer may relatively decrease, and there is a concern that the tensile strength and wear resistance may be significantly reduced in particular.

[0028] However, the composition for shoe outsole according to the present invention exhibits the best effect when the functional composition contains only butadiene rubber in an optimal amount.

[0029] In this way, when the functional composition contains only butadiene rubber, the content of the functional composition may be 3 to 7 wt%, preferably 4 to 6 wt%. In addition, the content of the polyurethane-based thermoplastic elastomer may be 93 to 97 wt%, preferably 94 to 96 wt%.

[0030] Meanwhile, the shoe outsole composition according to the present invention may further include, if necessary, at least one selected from the group consisting of acrylonitrile butadiene rubber, hydrogenated nitrile butadiene rubber, urethane rubber, acrylic rubber, isoprene rubber, styrenic block copolymers, polyolefin elastomers, and polyolefins. However, the composition may be included in a minimum amount within a range that does not inhibit the effect resulting from the organic relationship between the polyurethane thermoplastic elastomer and the functional composition. Here, the styrenic block copolymer may be, for example, a styrene-ethylene / butylene-styrene block copolymer, and may be used together with the polyolefin elastomer for the purpose of lowering the specific gravity. In addition, at least one selected from the group consisting of styrene-butadiene rubber, ethylene propylene rubber, and ethylene vinyl acetate may also be further included in the shoe outsole composition of the present invention as a separate entity rather than as a functional composition.

[0031] Meanwhile, the shoe outsole composition according to the present invention may further include, if necessary, one or more additives selected from the group consisting of zinc stearate, calcium stearate, an antioxidant, a crosslinking agent, a UV absorber, and a light stabilizer. Among these, calcium stearate, a crosslinking agent, a UV absorber, and a light stabilizer are particularly preferred in terms of controlling the crosslinking speed, improving dispersibility, improving physical properties, improving transparency, and preventing rubber aging.

[0032] Examples of the antioxidant include those commonly used in the art, but phosphite type or phenolic type antioxidants are particularly preferred. Examples of the crosslinking agent include those commonly used in the art, but peroxide type crosslinking agents are particularly preferred. Examples of the ultraviolet absorber include those commonly used in the art, but formamidine type ultraviolet absorbers are particularly preferred. Examples of the light stabilizer include those commonly used in the art, but hindered amine light stabilizers (HALS) are particularly preferred. However, in order to achieve the purpose of the present invention, the shoe outsole composition of the present invention preferably does not contain processing oils (e.g., paraffin oil, white oil, naphthenic oil, and aromatic oil, etc.) from the viewpoint of tensile strength and adhesive properties.

[0033] The above peroxide crosslinking agent has a purity of 99% or higher. If the purity of the peroxide crosslinking agent is less than 99%, there is a risk that transparency may be reduced. These peroxide crosslinking agents include cyclohexanone peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxylaurylate, t-butylperoxyacetate, di-t-butyldiperoxyphthalate, t-dibutylperoxymaleic acid, t-butylcumyl peroxide, t-butylhydroperoxide, t-butylperoxybenzoate, dibenzoyl peroxide, dicumyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, methylethylcapone peroxide, di-(2,4-dichlorobenzoyl)peroxide, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-(t-benzoylperoxy)hexane, Examples thereof include 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-(t-butylperoxy)-3-hexyne, n-butyl-4,4-bis(t-butylperoxy)valerate, a,a'-bis(t-butylperoxy)diisopropylbenzene, and those containing two or more of these.

[0034] If the shoe outsole composition of the present invention includes at least one additive selected from the group consisting of zinc stearate, calcium stearate, antioxidant, crosslinking agent, ultraviolet absorber, and light stabilizer, the zinc stearate may be included in an amount of 2 to 15 parts by weight based on 100 parts by weight of the total weight of the functional composition. The calcium stearate may also be included in an amount of 2 to 15 parts by weight based on 100 parts by weight of the total weight of the functional composition. The antioxidant may also be included in an amount of 2 to 15 parts by weight based on 100 parts by weight of the total weight of the functional composition. The crosslinking agent may be included in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the total weight of the functional composition. The ultraviolet absorber may be included in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total weight of the functional composition. The above light stabilizer may also be included in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total weight of the functional composition.

[0035] The present invention provides a shoe outsole manufactured using the shoe outsole composition described above. The shoe outsole according to the present invention has a tensile strength of 200 to 220 kgf / cm. 2 In addition, the shoe outer sole according to the present invention has an Akron wear index satisfying the following equation 1.

[0036] [Formula 1]

[0037]

[0038] And below, a method for manufacturing a shoe outer sole using the composition for the shoe outer sole is described.

[0039] The method for manufacturing a shoe outsole according to the present invention comprises the steps of: a) preparing a mixture by mixing a functional composition including butadiene rubber and an additive including a crosslinking agent in a kneader at 100 to 120°C for 10 to 20 minutes; b) preparing a composition for a shoe outsole by dynamically crosslinking and reaction extruding a polyurethane thermoplastic elastomer together with the mixture in an extruder or a closed kneader having a barrel temperature of 120 to 180°C; and c) forming a shoe outsole by injection molding or 3D printing the prepared composition for a shoe outsole.

[0040] The description of the functional composition, additives and polyurethane thermoplastic elastomer is identical to that described above in the section on composition for shoe outsole.

[0041] The extruder of step b) above may be a single-screw extruder or a twin-screw extruder.

[0042] The shoe outer sole composition manufactured in step b) or used in step c) may be in the form of pellets, for example, but is not limited thereto.

[0043] And, if injection molding is used in step c), for example, the shoe outer sole composition can be manufactured using a mold at a barrel temperature of 160 to 200°C. However, a 3D printing method, which is more environmentally friendly and easier to work with than the injection molding method, may be preferable.

[0044] In addition, since steps a) and b) above are included in the already widely known shoe outsole manufacturing process, a detailed description thereof will be omitted.

[0045] Hereinafter, the present invention will be described in more detail through specific examples. The following examples are intended to illustrate the present invention, and the present invention is not limited to the following examples.

[0046] [Examples 1-7] Manufacturing of shoe outsole specimens

[0047] According to the compositions in Table 1 or Table 2 below, the functional composition and additives were kneaded in a 110L internal kneader (manufacturer: Taekwang ENG) at 100 to 120°C for 10 to 20 minutes to prepare a kneaded material, and then a polyurethane thermoplastic elastomer (TPU) was dynamically crosslinked and reaction-extruded in an extruder set to a barrel temperature of 120 to 180°C to prepare a pellet-shaped composition for shoe outsoles. Subsequently, the prepared composition for shoe outsoles was injection-molded to prepare shoe outsole specimens according to Examples 1 to 7. In Tables 1 and 2 below, Examples 1 to 6 used only butadiene rubber as the butadiene-based rubber, and Example 7 used 2 wt% of butadiene rubber and 1 wt% of styrene-butadiene rubber as the butadiene-based rubber.

[0048]

[0049] * Content unit of polyurethane thermoplastic elastomer and functional composition: wt%

[0050] * Additive content (parts by weight): Based on 100 parts by weight of the total weight of the functional composition

[0051] * Antioxidant: bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite

[0052] * Cross-linking agent: bis(t-butylperoxy isopropyl)benzene

[0053] * UV absorber: N-(4-Ethoxycarbonylphenyl)-N'-Methyl-N' Phenylformamidine

[0054] * Light stabilizer: Poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-alt-1,4-butanedioic acid)

[0055]

[0056] * Content unit of polyurethane thermoplastic elastomer and functional composition: wt%

[0057] * Additive content (parts by weight): Based on 100 parts by weight of the total weight of the functional composition

[0058] * Antioxidant: bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite

[0059] * Cross-linking agent: bis(t-butylperoxy isopropyl)benzene

[0060] * UV absorber: N-(4-Ethoxycarbonylphenyl)-N'-Methyl-N' Phenylformamidine

[0061] * Light stabilizer: Poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-alt-1,4-butanedioic acid)

[0062]

[0063] [Comparative Examples 1-3] Manufacturing of shoe outsole specimens

[0064] According to the compositions in Table 3 below, the rubber composition and additives were kneaded in a 110L internal kneader (manufacturer: Taekwang ENG) at 100 to 120°C for 10 to 20 minutes to prepare a kneaded material, and then a polyurethane thermoplastic elastomer (TPU) was crosslinked and reaction-extruded in an extruder set to a barrel temperature of 120 to 180°C to prepare a composition for a shoe outsole in the form of pellets. Subsequently, the prepared composition for a shoe outsole was injection-molded to prepare shoe outsole specimens according to Comparative Examples 1 to 3.

[0065]

[0066] * Content unit of polyurethane thermoplastic elastomer and rubber composition: wt%

[0067] * Additive content (parts by weight) of Comparative Examples 1 and 2: Based on 100 parts by weight of the total weight of the rubber composition

[0068] * Additive content (parts by weight) of Comparative Example 3: Based on 100 parts by weight of the total weight of TPU and rubber composition

[0069] * Antioxidant: Bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite

[0070] * Cross-linking agent: cyclohexanone peroxide

[0071] * UV absorber: N-(4-Ethoxycarbonylphenyl)-N'-Methyl-N' Phenylformamidine

[0072]

[0073] [Comparative Examples 4 and 5] Manufacturing of shoe outsole specimens

[0074] Shoe outsole specimens according to Comparative Examples 4 and 5 were manufactured in the same manner as in Examples 1 to 7, except that the compositions were as shown in Table 4 below. In Table 4 below, Comparative Examples 4 and 5 used only butadiene rubber as the butadiene-based rubber.

[0075]

[0076] * Content unit of polyurethane thermoplastic elastomer and functional composition: wt%

[0077] * Additive content (parts by weight): Based on 100 parts by weight of the total weight of the functional composition

[0078] * Antioxidant: bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite

[0079] * Cross-linking agent: bis(t-butylperoxy isopropyl)benzene

[0080] * UV absorber: N-(4-Ethoxycarbonylphenyl)-N'-Methyl-N' Phenylformamidine

[0081] * Light stabilizer: Poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-alt-1,4-butanedioic acid)

[0082]

[0083] [Experimental Example] Evaluation of the Physical Properties of Shoe Outsoles

[0084] The shoe outsole specimens manufactured in Examples 1 to 7 and Comparative Examples 1 to 5 were evaluated using the items and methods below, and the results are shown in Tables 5 and 6 below.

[0085]

[0086] 1) Hardness (Shore A): An Asker A type hardness tester was used and measured according to the ASTM D-2240 standard test method.

[0087] 2) Tensile strength (kgf / cm) 2 ) and elongation (%): After making test pieces using die A, the manufactured specimens were measured for tensile strength and elongation according to the ASTM D-412 standard test method. At this time, 5 test pieces were used for the same test.

[0088] 3) Tear strength (kgf / cm): Measured according to the ASTM D-634 standard test method, and after repeating the test 5 times, specimens that deviated by more than 20% from the median were excluded and the average was measured.

[0089] 4) Wear resistance (Akron): Measured according to KSM 6624, and Akron wear (cc lose) was calculated using the following formula 1.

[0090] [Formula 1]

[0091]

[0092] 5) QUV (Quick UV Accelerated Weatherability, Gray scale): Evaluated according to AATCC 186.

[0093] 6) Yellowing phenomenon: Evaluated through visual inspection over time.

[0094] 7) Transparency: Total light transmittance and haze were evaluated using a spectrophotometer and haze meter according to ASTM 1003.

[0095] 8) Slip resistance (wet): Slip resistance was evaluated by measuring the dynamic friction coefficient when the specimen was moved at a constant speed on a glass plate sprayed with water (wet) according to ASTM D1894.

[0096]

[0097]

[0098] As a result of measuring the physical properties of each shoe outsole specimen manufactured in Examples 1 to 7 and Comparative Examples 1 to 5, the shoe outsole specimens of Examples 1 to 7 showed that, as the content of butadiene rubber increased, the properties (elongation, slip resistance, and flexibility) that are particularly important in the shoe industry were much better than the shoe outsole specimens of Comparative Examples 1 to 5 (in particular, both elongation and slip resistance must be excellent properties at the same time).

[0099] In addition, the applicant of the present invention attempted to maintain the non-slip properties at a level similar to that of the prior art by using a polyurethane-based thermoplastic elastomer known to have a particular advantage in non-slip properties (or, slip resistance), but as a result of conducting the experiment within the composition and content range of the present invention, it was confirmed that the non-slip properties were also improved compared to the prior art.

[0100] Therefore, it can be seen that when a composition for a shoe outer sole is manufactured through a specific mixing method, such as using butadiene rubber in a smaller amount than before and not using silicone rubber, the physical properties of the shoe outer sole are improved compared to before.

Claims

1. Contains 91 to 97 wt% of a polyurethane-based thermoplastic elastomer; and 3 to 9 wt% of a functional composition; A composition for a shoe outer sole, wherein the functional composition comprises butadiene rubber.

2. A composition for a shoe outer sole according to claim 1, wherein the composition for a shoe outer sole does not contain silicone rubber and processing oil.

3. A composition for a shoe outsole according to claim 1, wherein the functional composition further comprises at least one selected from the group consisting of styrene butadiene rubber, ethylene propylene rubber, and ethylene vinyl acetate.

4. A composition for a shoe outer sole according to claim 1, wherein the polyurethane-based thermoplastic elastomer has a hardness of 65 to 85A (asker A).

5. A composition for a shoe outer sole according to claim 1, wherein the composition for a shoe outer sole further comprises at least one selected from the group consisting of acrylonitrile butadiene rubber, hydrogenated nitrile butadiene rubber, urethane rubber, acrylic rubber, isoprene rubber, styrene-based block copolymer, polyolefin elastomer, and polyolefin.

6. A composition for a shoe outer sole according to claim 1, wherein the composition for a shoe outer sole further comprises at least one additive selected from the group consisting of zinc stearate, calcium stearate, an antioxidant, a crosslinking agent, an ultraviolet absorber, and a light stabilizer.

7. A shoe outsole manufactured using the shoe outsole composition of any one of claims 1 to 6.

8. In claim 7, the tensile strength of the shoe outer sole is 200 to 220 kgf / cm. 2 The outer sole of the shoe.

9. A shoe outsole according to claim 8, wherein the Akron wear of the shoe outsole satisfies the following mathematical formula 1. [Formula 1] 10.a) A step of preparing a mixed material by kneading a functional composition containing butadiene rubber and an additive containing a crosslinking agent in a kneader at 100 to 120°C for 10 to 20 minutes; b) a step of dynamically crosslinking and reaction extruding a polyurethane thermoplastic elastomer together with the above-mentioned manufactured mixture in an extruder or closed mixer having a barrel temperature of 120 to 180°C to manufacture a composition for a shoe outer sole; and c) A method for manufacturing a shoe outer sole, comprising the step of forming a shoe outer sole by injection molding or 3D printing the manufactured shoe outer sole composition.

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