KR102097400B1 - A composition for shoes midsole and a method for manufacturing shoes midsole using the same - Google Patents

Abstract

One embodiment of the present invention provides a composition for a shoe midsole, comprising 1 to 10 parts by weight of a metal oxide, 0.1 to 5 parts by weight of a lubricant and 1 to 5 parts by weight of a blowing agent, based on 100 parts by weight of a main resin comprising a first ethylene vinyl acetate and a second ethylene vinyl acetate having a monomer composition different from the same of the first ethylene vinyl acetate. The composition for a shoe midsole has improved resilience and lightweightness.

Description

Composition for shoe midsole and method for manufacturing shoe midsole using the same {A COMPOSITION FOR SHOES MIDSOLE AND A METHOD FOR MANUFACTURING SHOES MIDSOLE USING THE SAME}

The present invention relates to a composition for a shoe midsole having excellent light weight and a method for manufacturing a shoe midsole using the same.

Shoes are worn to protect the human foot parts and are manufactured and sold in various shapes and types, but normally, they protect the upper and the soles by covering the insteps and ankles while increasing the friction between the ground and the foot. It is composed of a sole that improves walking and at the same time relieves the impact on the sole of the foot when walking.

The sole is attached to the midsole made of rubber, foamed resin, or sponge material with excellent buffering power to elastically distribute and support the load of the human body when walking, and is attached to the bottom surface of the midsole to provide friction when walking It is made of outsole made of rubber material.

In general, midsoles are generally made of ethylene vinyl acetate (EVA) and polyurethane (Polyurethane). The ethylene vinyl acetate is excellent in light weight, inexpensive, soft and excellent in cushioning, but has a low resilience, so that cushioning may occur over time. The polyurethane has a relatively less cushioning feeling than ethylene vinyl acetate, but has excellent durability and elasticity, is fast in recovery even under a long pressure, and has excellent processability and moldability. However, the polyurethane may crack due to hydrolysis over time and the material itself is heavy, which can increase a user's foot fatigue when worn for a long time.

In order to solve this problem, a technique has been proposed to improve recovery and durability by including a metal oxide in the ethylene vinyl acetate, but when a large amount of metal oxide is included, the manufacturing cost is increased as well as the lightweightness of the shoe is reduced. Can be.

Accordingly, there is a need to develop a technology for a shoe midsole composition that is excellent in light weight while improving resilience and durability by including a small amount of metal oxide.

The present invention is to solve the problems of the prior art described above, the object of the present invention is a composition for shoe midsole comprising two kinds of ethylene vinyl acetate having a different composition of the monomer and containing metal oxide to improve recovery and light weight. It is to provide a method for manufacturing a shoe midsole using this.

One aspect of the present invention, with respect to 100 parts by weight of the main resin comprising a first ethylene vinyl acetate and a second ethylene vinyl acetate having a monomer composition different from the first ethylene vinyl acetate, metal oxide 1 to 10 parts by weight, lubricant 0.1 It provides a composition for shoe midsole comprising ~ 5 parts by weight and 1 to 5 parts by weight of a blowing agent.

In one embodiment, the content of vinyl acetate in the first ethylene vinyl acetate may be 15 to 30% by weight.

In one embodiment, the content of vinyl acetate in the second ethylene vinyl acetate may be 5 to 15% by weight.

In one embodiment, the content of the first ethylene vinyl acetate in the main resin may be 10 to 90% by weight.

In one embodiment, the metal oxide may include zinc oxide and titanium oxide.

In one embodiment, the content of the zinc oxide in the metal oxide may be 50 to 90% by weight.

In one embodiment, the shoe midsole composition may further include a crosslinking agent and a crosslinking aid.

In one embodiment, the crosslinking agent may be a peroxide-based crosslinking agent.

In one embodiment, the lubricant may be stearic acid.

In addition, another aspect of the present invention provides a method for manufacturing a shoe midsole comprising the step of foam-molding the composition for the shoe midsole.

The composition for shoe midsole according to an embodiment of the present invention and the method for manufacturing the scatter midsole using the same include two types of ethylene vinyl acetate having different monomer compositions as a main resin, and a small amount of metal oxide to contain the composition for shoe midsole. By manufacturing and manufacturing a shoe midsole using the same, finally, the durability and resilience of the shoe midsole can be improved while lightening the shoe.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

Hereinafter, the present invention will be described. However, the present invention may be implemented in various different forms, and thus is not limited to the embodiments described herein.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "indirectly connected" with another member in between. . Also, when a part is said to “include” a certain component, this means that other components may be further provided instead of excluding the other component unless otherwise stated.

Hereinafter, embodiments of the present invention will be described in detail.

Shoe midsole composition according to an aspect of the present invention, with respect to 100 parts by weight of the main resin comprising a first ethylene vinyl acetate and a second ethylene vinyl acetate having a monomer composition different from the first ethylene vinyl acetate, metal oxide 1 ~ It may include 10 parts by weight, 0.1 to 5 parts by weight of lubricant, and 1 to 5 parts by weight of blowing agent.

Conventional shoe midsoles were manufactured using ethylene vinyl acetate or polyurethane as the main resin. Polyurethane has excellent durability, processability, moldability, and resilience compared to ethylene vinyl acetate, but the material itself is heavy and the weight of shoes increases, and users who wear it are forced to feel fatigue within a short period of time. The ethylene vinyl acetate material itself has excellent light weight, but there is a problem that the resilience and durability are lower than that of polyurethane.

On the other hand, the composition for shoe midsole of the present invention is ethylene comprising two types of ethylene vinyl acetate having different monomer compositions, that is, the first ethylene vinyl acetate and the second ethylene vinyl acetate having a different monomer composition from the first ethylene vinyl acetate. By using the vinyl acetate mixture as the main resin, it is possible to appropriately compensate for the resilience, durability, mechanical properties, etc., which are lacking in the conventional ethylene vinyl acetate.

The ethylene vinyl acetate itself is excellent in light weight, but the flexibility and adhesiveness of the resin can be determined by the polymerization degree and the content of vinyl acetate. For example, when the content of vinyl acetate in the ethylene vinyl acetate increases, flexibility and adhesiveness may be improved. However, as the content of vinyl acetate increases, there is a problem in that the adhesiveness increases during processing and the workability decreases.

In addition, since ethylene vinyl acetate alone is difficult to sufficiently implement durability and mechanical properties, and in particular, when it is made of a foam, tensile strength, etc. is reduced. Therefore, partial physical crosslinking including a crosslinking agent may improve mechanical properties. .

The ethylene vinyl acetate can be prepared by emulsion polymerization, solution polymerization and / or suspension polymerization of monomers.

The emulsion polymerization is a method in which an oil-soluble monomer is emulsified in water by a surfactant and polymerized using a water-soluble initiator. Polymerization is performed in a micelle in which a monomer is introduced, and a polymer of high polymerization degree is used in this process. Can be obtained.

The solution polymerization is a method in which an oil-soluble monomer is dissolved in a solvent, for example, an organic solvent, and then polymerized using an initiator.

The suspension polymerization is performed in a micelle of a suspended monomer using a polymerization initiator having a property of dissolving the monomer in a medium in which the monomer is hardly dissolved and insoluble in the monomer without dissolving in the medium, and dispersed form As soon as the polymerization can proceed.

The content of vinyl acetate in the first ethylene vinyl acetate may be 15 to 30% by weight. If the content of vinyl acetate in the first ethylene vinyl acetate is less than 15% by weight, flexibility and adhesiveness may be reduced, and if it is more than 30% by weight, workability may be reduced.

In one embodiment, the content of vinyl acetate in the second ethylene vinyl acetate may be 5 to 15% by weight. If the content of vinyl acetate in the second ethylene vinyl acetate is less than 5%, the restoring force may be lowered, and if it is more than 15% by weight, workability may be lowered.

In one embodiment, the content of the first ethylene vinyl acetate in the main resin may be 10 to 90% by weight. If the content of the first ethylene vinyl acetate in the main resin is less than 10% by weight, the restoring force may be reduced, and if it is more than 90% by weight, durability and mechanical properties may be deteriorated.

The first and second ethylene vinyl acetates have different monomer compositions and are included by adjusting the content in the above range in the main resin, thereby improving the durability and resilience of the shoe midsole, which is the final product, while maximizing light weight.

The metal oxide may include zinc oxide and titanium oxide. The metal oxide may be included in a main resin comprising first and second ethylene vinyl acetate to improve mechanical properties of the shoe sole composition.

When the composition for shoe midsole is made of only ethylene vinyl acetate, weight reduction of the shoe can be realized, but durability and mechanical properties are lowered to increase the defective rate of the shoe, as well as the user's feeling of wearing and wearing. However, when a large amount of metal oxide is included, compatibility and processability with the main resin are reduced, and as the content of the metal component increases, the weight of the shoe midsole becomes heavy, which may also act as a factor to lower the user's ignition feeling. have.

Therefore, by including a small amount of metal oxide in the first and second ethylene vinyl acetate having a different composition of monomers, it is possible to finally realize the weight reduction of shoes and improve the durability and recovery of the shoe midsole.

The content of the metal oxide may be 1 to 10 parts by weight based on 100 parts by weight of the main resin. If the content of the metal oxide in the composition for the shoe midsole is less than 1 part by weight, durability and mechanical properties of the shoe may be deteriorated, and if it is more than 10 parts by weight, the metal oxide in the composition may be contained in a large amount, thereby reducing the lightness of the shoe. have.

The zinc oxide may be included and dispersed in the main resin to control the crosslinking rate and promote foaming.

The content of the zinc oxide in the metal oxide may be 50 to 90% by weight. If the content of the zinc oxide in the metal oxide is less than 50% by weight, the crosslinking speed may be slow, and the defective rate of shoes may increase. If it is more than 90% by weight, the crosslinking rate may be higher than necessary, thereby reducing the flexibility and resilience of the shoe midsole. have.

The titanium oxide is included in the shoe midsole composition together with the zinc oxide to control a crosslinking rate and realize a synergistic effect to maximize foam formation. In addition, the titanium oxide may serve as a pigment, and may give a white color in the foaming process when manufacturing the shoe midsole.

The shoe midsole composition may include a lubricant, and the lubricant may be stearic acid. The stearic acid may serve to uniformly disperse the composition for shoe midsole. Specifically, the stearic acid is contained in the composition for the shoe midsole, it is possible to prevent the particles from agglomerating by finely pulverizing and uniformly dispersing large particles or aggregated particles in the composition into smaller particles.

The amount of the lubricant may be 0.1 to 5 parts by weight based on 100 parts by weight of the main resin. If the content of the lubricant is less than 0.1 parts by weight, the dispersing effect may be weak, and if it is more than 5 parts by weight, the viscosity of the resin may be excessively lowered to deteriorate workability.

The shoe midsole composition may include a blowing agent. The type of the blowing agent may be one selected from the group consisting of azodicarbonamide, dinitrosopentamethyltetraamine, azobisisobutylnitrile, p-toluenesulfonyl hydrazide, and combinations of two or more of these, preferably , Azodicarbon amide, but is not limited thereto.

The content of the blowing agent may be 1 to 5 parts by weight based on 100 parts by weight of the main resin. If the content of the foaming agent is less than 1 part by weight, light weight may be reduced, and if it is more than 5 parts by weight, durability of the shoe midsole may be reduced.

Meanwhile, the shoe midsole composition may further include additives such as a crosslinking agent, a crosslinking aid, a pigment, and a dye.

The crosslinking agent may be a peroxide-based crosslinking agent. The crosslinking agent is, for example, dicumyl peroxide, t-butyl peroxy laurylate, t-dibutyl peroxy maleic acid, t-butyl hydroperoxide, 2,5-dimethyl-2,5-di (t- Butylperoxy) nucleic acid, di-t-butylperoxide and 1,3-bis (t-butylperoxyisopropylene) benzene, and combinations of two or more of them, preferably diku Milperoxide may be, but is not limited to.

The content of the crosslinking agent may be 0.1 to 5 parts by weight based on 100 parts by weight of the main resin. If the content of the crosslinking agent is less than 0.1% by weight, the durability and mechanical properties of the shoe midsole may deteriorate, and if it is more than 5 parts by weight, the flexibility and resilience of the shoe midsole may deteriorate.

The crosslinking aid may serve as a crosslinking accelerator that promotes a crosslinking reaction together with the crosslinking agent. The crosslinking aid is, for example, triallyl cyanurate, triallyl isocyanurate, trimethylol, polybutadiene, propane trimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, butyl It may be one selected from the group consisting of alkylene glycol acrylate, butylene glycol dimethacrylate, metal-acrylate, metal-methacrylate, and combinations of two or more of these, preferably, triallyl cyanurate. However, it is not limited thereto.

The content of the crosslinking aid may be 0.1 to 2 parts by weight based on 100 parts by weight of the main resin. If the content of the crosslinking aid is less than 0.1 part by weight, the durability and mechanical properties of the shoe midsole may be reduced, and if it is more than 2 parts by weight, the flexibility and resilience of the shoe midsole may be reduced.

In addition, to achieve the above object, another aspect of the present invention provides a method for manufacturing a shoe midsole comprising the step of foaming a composition for a shoe midsole.

The manufacturing method of the shoe midsole may be a press method or an injection method. The shoe midsole may be manufactured by a press method or an injection method using the composition for the shoe midsole, and may be selected in consideration of a desired purpose, equipment, effect, and the like.

In the press method, a shoe sole composition can be foamed and expanded separately, produced in a sheet form using a press, cut into a size required for manufacturing, put into a press mold, pressurized at high temperature and high pressure, and cooled to produce a shoe midsole. . In addition, the injection method may manufacture a shoe midsole through injection molding in which a composition for a shoe midsole is manufactured into a pellet-shaped compound through an extruder, and injected into the injection mold to maintain cross-linking and foaming while maintaining a heating state.

The method for manufacturing the shoe midsole may include mixing the composition for the shoe midsole before including the step of foaming. The shoe midsole composition comprises a metal oxide, a lubricant, a blowing agent and other additives with respect to 100 parts by weight of the main resin comprising a first ethylene vinyl acetate and a second ethylene vinyl acetate having a monomer composition different from that of the first ethylene vinyl acetate. The mixture may be introduced into a mixer to be mixed, and the mixer may be a kneader machine, a ban-bury mixer, or an open roll mill, but preferably a kneader machine.

Mixing in the kneader group may be performed at 70 to 100 ° C, uniform mixing may be difficult if the temperature is less than 70 ° C, and when it is greater than 100 ° C, additives such as a crosslinking agent and a blowing agent may decompose to degrade physical properties. Can be.

The extruder may be a single screw extruder or a twin screw extruder. As used herein, the terms "single-screw extruder" and "twin-screw extruder" mean a screw-type extruder each having one and two screws.

The single-screw extruder is suitable for extrusion molding of most thermoplastic resins, and the twin-screw extruder is mainly used for the production of large-diameter pipes, for example, polyvinyl chloride (PVC) pipes. The twin-screw extruder has a complicated structure and is expensive compared to a single-screw extruder, but it is widely used because it has a large amount of extrusion and a constant and stable extrusion even at a slow screw driving speed.

The extrusion temperature may be performed at 100 ~ 150 ℃. In consideration of the possibility of destruction of the mixture due to pressure and temperature applied to the mixture in the extrusion process, the extrusion temperature of the extruder may be differently adjusted according to the type of the composition.

Meanwhile, the ratio of the length: diameter of the extruder may be 25 to 50: 1. The “length: diameter ratio” of the extruder means a ratio of the length (L) and the diameter (D) of the screw, which is one of the factors determining the extrusion performance of the extruder. In general, the larger the "length: diameter ratio" of the screw, the better the kneading effect and the quality of the product and reduce the variation in extrusion amount, but the ratio of the length: diameter depends on the type and nature of the material being administered to the extruder. It can be adjusted differently.

If the ratio of the length of the extruder to the diameter is less than 25: 1, a kneading effect of a required level cannot be achieved, and if it exceeds 50: 1, the process efficiency may be reduced by affecting the size of the extruder and the capacity of the driving motor.

In addition, the driving speed of the extruder may be 50 to 500 rpm. The driving speed of the extruder means the rotational speed of the screw provided in the extruder, and if the driving speed of the extruder is less than 50 rpm, the required level of kneading effect cannot be achieved, and if it exceeds 500 rpm, the rotation of the motor compared to the number of rotations of the screw Since the number is remarkably large, it may cause damage by applying an excessive load to the motor and the reduction gear.

Hereinafter, embodiments of the present invention will be described in detail.

Example  One

With respect to 100 parts by weight of the resin composition consisting of 70% by weight of the first ethylene vinyl acetate containing 20% by weight of vinyl acetate and 30% by weight of the second ethylene vinyl acetate containing 10% by weight of vinyl acetate, 8 parts by weight of zinc oxide, oxidation 2 parts by weight of titanium, 3 parts by weight of stearic acid, 5 parts by weight of dicumyl peroxide, 2 parts by weight of triallyl cyanurate, and 5 parts by weight of azodicarbonamide were added to the kneader and kneaded at 70 ° C for 10 minutes to prepare a mixture. .

The mixture was first pressed at 90 ° C, 140kgf / cm2 for 8 minutes using a pouring foaming method to make a preform in the form of a sheet, then put it into a mold and cooled after 160 ° C, 150kgf / cm2, and 15 minutes for a second press The press was cooled for 10 minutes to prepare a shoe midsole.

Example  2

With respect to 100 parts by weight of the resin composition consisting of 70% by weight of the first ethylene vinyl acetate containing 20% by weight of vinyl acetate and 30% by weight of the second ethylene vinyl acetate containing 10% by weight of vinyl acetate, 8 parts by weight of zinc oxide, oxidation 2 parts by weight of titanium, 3 parts by weight of stearic acid, 5 parts by weight of dicumyl peroxide, 2 parts by weight of triallyl cyanurate, and 5 parts by weight of azodicarbonamide were added to the kneader and kneaded at 70 ° C for 10 minutes to prepare a mixture. .

The mixture was prepared using a twin-screw extruder under the conditions of 200 ° C. and 250 rpm, and then cut to prepare pellet-type compounds.

The manufactured compound was put into an injection mold and injection molded at 160 ° C for 8 minutes to produce a shoe midsole.

Example  3

A shoe midsole was manufactured in the same manner as in Example 1, except that no triallyl cyanurate was added.

Example  4

A shoe midsole was manufactured in the same manner as in Example 1, except that dicumyl peroxide and triallyl cyanurate were not added.

Comparative example  One

With respect to 100 parts by weight of ethylene vinyl acetate containing 20% by weight of vinyl acetate, 8 parts by weight of zinc oxide, 2 parts by weight of titanium oxide, 3 parts by weight of stearic acid, 5 parts by weight of dicumyl peroxide, 2 parts by weight of triallyl cyanurate , 5 parts by weight of azodicarbonamide was added to a kneader and kneaded at 70 ° C for 10 minutes to prepare a mixture.

The mixture was first pressed at 90 ° C, 140kgf / cm2 for 8 minutes using a pouring foaming method to make a preform in the form of a sheet, then put it into a mold and cooled after 160 ° C, 150kgf / cm2, and 15 minutes for a second press The press was cooled for 10 minutes to prepare a shoe midsole.

Comparative example  2

A shoe midsole was manufactured in the same manner as in Example 1, except that 5 parts by weight of magnesium carbonate and 5 parts by weight of calcium carbonate were further added to the composition for shoe soles.

Comparative example  3

A shoe midsole was manufactured in the same manner as in Example 1, except that the addition amount of azodicarbonamide was adjusted to 10 parts by weight.

Comparative example  4

A shoe midsole was manufactured in the same manner as in Example 1, except that the azodicarbonamide was not included.

Comparative example  5

A shoe midsole was manufactured in the same manner as in Example 1, except that zinc oxide and titanium oxide were not included.

Experimental example : Evaluation of shoe midsole properties

The physical properties of the shoe midsole manufactured according to the above Examples and Comparative Examples were evaluated, and the results are shown in Table 1 below. The property evaluation method is as follows.

-Specific gravity: Measured 5 times using Uesima's automatic specific gravity measuring device according to KS M 6660 and expressed as an average value

-Hardness: Measured using the Asker C type hardness tester according to KS M 6660

-Tensile strength: Measured using Zwick's universal tester according to KS M ISO 1798

-Tear strength: measured by KS M ISO 7214 using Zwick's universal tester

-Elongation: Measured using Zwick's universal tester according to KS M ISO 1798

-Permanent compression reduction rate: The test piece prepared in the form of a cylinder with a diameter of 30 ± 0.05mm and a thickness of about 10 mm in the midsole manufactured by KS M 6518 was compressed by 50% of the original thickness and heat-treated at 50 ± 0.1 ℃ for 6 hours. After cooling for 30 minutes at room temperature, the thickness was measured. Three specimens were used, and the values were average values.

-Rebound resilience: Measured by KS M ISO 8307 using Daesung Science's rebound resilience tester.

division importance
(g / cc) Hardness
(Asker, C) The tensile strength
(MPa) Tear strength
(N / mm) Elongation
(%) Permanent compression reduction rate
(%) Resilience
(%) Example 1 0.20 60 20 12 300 55 40 Example 2 0.21 58 20 13 290 52 40 Example 3 0.21 55 18 10 285 53 38 Example 4 0.24 50 15 10 280 51 37 Comparative Example 1 0.21 45 12 8 252 45 32 Comparative Example 2 0.42 50 17 9 220 40 28 Comparative Example 3 0.20 37 13 7 230 35 24 Comparative Example 4 0.22 52 14 10 260 42 33 Comparative Example 5 0.21 54 15 8 250 43 34

Referring to Table 1, shoe midsoles containing two types of ethylene vinyl acetate and a small amount of metal oxide (Examples 1 and 2) have a specific gravity of 0.2, and thus it can be confirmed that light weight is excellent. In addition, mechanical properties such as hardness and tensile strength were found to be the best compared to other examples and comparative examples, and in particular, the permanent compression reduction ratio was highest at 55%, which was produced using the shoe midsoles of Examples 1 and 2 Old shoes are expected to have excellent durability and resilience while being lightweight.

On the other hand, when the crosslinking aid was not included (Example 3) and when the crosslinking agent and the crosslinking aid were not included (Example 4), the light weight was excellent, but the properties of hardness, strength, etc. were measured to be lowered, and the crosslinking performance was lowered. As a result, it was confirmed that durability was reduced.

On the other hand, when manufactured with one type of ethylene vinyl acetate (Comparative Example 1), it can be confirmed that other physical properties other than specific gravity were deteriorated, and when it was prepared with a large amount of metal oxide compared to the Example (Comparative Example) 2) The specific gravity was shown to be increased, confirming that the weight of the shoe midsole was increased by the metal oxide. In addition, it was confirmed that when the amount of the first ethylene vinyl acetate added was too small or too large, it was lowered in all properties except specific gravity.

The above description of the present invention is for illustration only, and those skilled in the art to which the present invention pertains can understand that it can be easily modified to other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted to be included in the scope of the present invention.

Claims (10)

With respect to 100 parts by weight of the main resin comprising a first ethylene vinyl acetate and a second ethylene vinyl acetate having a different monomer composition from the first ethylene vinyl acetate,
1 to 10 parts by weight of metal oxide, 0.1 to 5 parts by weight of lubricant and 1 to 5 parts by weight of blowing agent,
The content of vinyl acetate in the first ethylene vinyl acetate is 15 to 20% by weight,
The content of vinyl acetate in the second ethylene vinyl acetate is 5 to 10% by weight,
The content of the first ethylene vinyl acetate in the main resin is prepared using a composition for shoe soles of 70 to 90% by weight,
The hardness measured using the Asker C-type hardness tester is 55 to 60,
Tensile strength is 18 ~ 20MPa,
The tear strength is 10 ~ 13N / mm,
The elongation is 285 ~ 300%, the shoe midsole. delete delete delete According to claim 1,
The metal oxide is a shoe midsole comprising zinc oxide and titanium oxide. The method of claim 5,
The content of the zinc oxide in the metal oxide is 50 to 90% by weight of the shoe midsole. According to claim 1,
The shoe midsole composition further comprises a crosslinking agent and a crosslinking aid. The method of claim 7,
The cross-linking agent is a peroxide-based cross-linking agent shoe midsole. According to claim 1,
The lubricant is a midsole shoe that is stearic acid. delete