KR20220063777A - A composition for shoe parts - Google Patents

Abstract

One aspect of the present invention provides a composition for shoe parts which comprises: 1 to 10 parts by weight of a metal oxide; 0.1 to 5 parts by weight of a lubricant; and 1 to 10 parts by weight of a foaming agent based on 100 parts by weight of a main resin which includes: a first ethylene vinyl acetate; a second ethylene vinyl acetate having a different monomer composition from the first ethylene vinyl acetate; and a crystalline polymer.

Description

Composition for shoe member {A COMPOSITION FOR SHOE PARTS}

The present invention relates to a composition for a shoe member and a shoe member manufactured using the same.

Shoes are worn to protect the feet of the human body, and are manufactured and sold in various shapes and types. However, in general, the upper and the sole of the foot are protected by covering the instep and ankle, and friction with the ground is increased. It is composed of a sole that improves gaitability and at the same time alleviates the impact applied to the sole of the foot during walking.

The sole is a midsole made of rubber, foamed resin, or sponge material with excellent cushioning power so as to elastically distribute and support the load of the human body during walking, and is attached to the bottom surface of the midsole to impart friction when walking. It consists of an outsole made of a rubber material for this purpose.

In general, midsoles are generally manufactured using ethylene vinyl acetate (EVA), polyurethane, etc. as main materials. The ethylene vinyl acetate is excellent in light weight, low in price, soft and has excellent cushioning, but the cushioning effect may occur over time due to low restoring force. The polyurethane has relatively less cushioning than ethylene vinyl acetate, but has excellent durability and elasticity, recovers quickly even when pressure is applied for a long time, and has excellent processability and moldability. However, as time elapses, polyurethane crumbles due to hydrolysis, and since the material itself is heavy, it may increase the user's foot fatigue when worn for a long time.

In order to solve this problem, a technique for improving recovery and durability by including a metal oxide in the ethylene vinyl acetate has been proposed. In addition to deterioration, there is a problem in that durability, restoring force, etc. imparted to the shoe member immediately after manufacturing cannot be maintained for a long period of time and deteriorated within a short period of time.

Therefore, there is a demand for technology development of a composition for a shoe member that contains a small amount of metal oxide and has excellent lightness while improving restoring force and durability.

SUMMARY OF THE INVENTION The present invention is to solve the problems of the prior art described above, and an object of the present invention is to improve durability, resilience and lightness while maintaining these properties for a long period of time, and a composition for a shoe member and a shoe member using the same is to provide

In one aspect of the present invention, with respect to 100 parts by weight of the main resin including the first ethylene vinyl acetate, the second ethylene vinyl acetate having a monomer composition different from that of the first ethylene vinyl acetate, and a crystalline polymer, 1 to 10 metal oxides It provides a composition for a shoe member comprising parts by weight, 0.1 to 5 parts by weight of a lubricant, and 1 to 10 parts by weight of a foaming agent.

In one embodiment, the content of the crystalline polymer in the main resin may be 5 to 30% by weight.

In one embodiment, the content of vinyl acetate in the first ethylene vinyl acetate may be 20 to 30% by weight.

In one embodiment, the content of the vinyl acetate in the second ethylene vinyl acetate may be 5 to 20% by weight.

In one embodiment, the content of the first ethylene vinyl acetate in the main resin may be 40 to 90% by weight.

In one embodiment, the crystalline polymer may include one selected from the group consisting of polyolefin, polyester, polycarbonate, polyamide, polyimide, and combinations of two or more thereof.

In one embodiment, the metal oxide may include zinc oxide, titanium oxide, or a combination thereof.

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

Another aspect of the present invention provides a shoe member manufactured by foaming the composition for a shoe member.

In one embodiment, the shoe member may satisfy the following conditions.

<expression>

B/A ≥ 0.9

In the above formula, A is the rebound elasticity (%) measured immediately after manufacturing the shoe member, which is 40 or more, and B is the rebound elasticity (%) measured 7 days after manufacturing the shoe member.

The composition for a shoe member according to an aspect of the present invention and a shoe member using the same include two kinds of ethylene vinyl acetate and a crystalline polymer having different monomer compositions as main resins, thereby improving the durability, resilience, and stability of the shoe member and the shoe including the same. While improving lightness, it is possible to maintain these properties imparted during manufacturing of the shoe member for a long period of time.

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 inferred 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 embodied in several different forms, and thus is not limited to the embodiments described herein.

Throughout the specification, when a part is "connected" with another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

In one aspect of the present invention, with respect to 100 parts by weight of the main resin including the first ethylene vinyl acetate, the second ethylene vinyl acetate having a monomer composition different from that of the first ethylene vinyl acetate, and a crystalline polymer, 1 to 10 metal oxides It provides a composition for a shoe member comprising parts by weight, 0.1 to 5 parts by weight of a lubricant, and 1 to 10 parts by weight of a foaming agent.

A conventional shoe member, for example, a shoe midsole was manufactured using ethylene vinyl acetate and/or polyurethane as a main resin. Polyurethane is relatively superior in durability, processability, moldability, and resilience compared to ethylene vinyl acetate, but the material itself is heavy, which increases the weight of the shoe, and users who wear it feel fatigue within a short period of time. Ethylene vinyl acetate is excellent in light weight, but there is a problem in that restoring force and durability are lowered compared to polyurethane.

In contrast, the main resin of the composition for the shoe member is composed of two types of ethylene vinyl acetate, that is, a first ethylene vinyl acetate, a second ethylene vinyl acetate having a monomer composition different from that of the first ethylene vinyl acetate, and a crystalline polymer. By including, restoring force, durability, mechanical properties and the persistence of these properties that are lacking in conventional ethylene vinyl acetate can be properly compensated.

Although the ethylene vinyl acetate itself is excellent in light weight, the flexibility and adhesiveness of the resin can be determined by the degree of polymerization and the content of vinyl acetate. For example, when the content of vinyl acetate in the ethylene vinyl acetate is increased, flexibility and adhesion may be improved. However, as the content of vinyl acetate increases, there is a problem in that the processability is deteriorated due to an increase in adhesion during processing.

In addition, it is difficult to sufficiently implement durability and mechanical properties with ethylene vinyl acetate alone, and in particular, when it is used as a foam, tensile strength and the like decrease.

The ethylene vinyl acetate may be prepared by emulsion polymerization, solution polymerization, and/or suspension polymerization of a monomer.

The emulsion polymerization is a method of emulsifying an oil-soluble monomer in water with a surfactant and polymerizing it using a water-soluble initiator. 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 micelles of the suspended monomers by dispersing the monomers in a medium in which the monomers are hardly soluble and using a polymerization initiator that is not soluble in the medium and dissolves well in the monomers. Polymerization may proceed as is.

The content of vinyl acetate in the first ethylene vinyl acetate may be 20 to 30% by weight. If the content of vinyl acetate in the first ethylene vinyl acetate is less than 20% by weight, flexibility and adhesiveness may be reduced, and if it exceeds 30% by weight, processability may be reduced.

The content of vinyl acetate in the second ethylene vinyl acetate may be 5 to 20% by weight. If the content of vinyl acetate in the second ethylene vinyl acetate is less than 5 weight, the restoring force may be reduced, and if it exceeds 20 weight %, processability may be reduced.

The content of the first ethylene vinyl acetate in the main resin may be 40 to 90% by weight. If the content of the first ethylene vinyl acetate in the main resin is less than 40% by weight, restoring force may be reduced, and if it exceeds 90% by weight, durability and mechanical properties may be reduced.

The crystalline polymer not only improves some physical properties, for example, durability, resilience, mechanical properties, of a shoe member manufactured by using the composition for a shoe member, but also provides durability so that these properties are maintained for a long period of time. there is. However, since these crystalline polymers generally have a high processing temperature, for example, a melting point and a softening point, it is difficult to process at about 100 to 150° C., which is the processing temperature of the ethylene vinyl acetate. there is

However, when the processing temperature of the crystalline polymer is relatively low and the compatibility and compatibility with the ethylene vinyl acetate are good or if the ones having excellent compatibility are selectively applied, this problem can be appropriately solved.

The crystalline polymer may be a thermoplastic polymer, and the thermoplastic polymer is, for example, one selected from the group consisting of polyolefin, polyester, polycarbonate, polyamide, polyimide, and combinations of two or more thereof. It may include, and preferably, may be a polyolefin, but is not limited thereto.

The weight average molecular weight (Mw) of the polyolefin may be 1,000 to 100,000 g/mol, preferably, 1,000 to 50,000 g/mol, more preferably, 1,000 to 30,000 g/mol. When the weight average molecular weight of the polyolefin is less than 1,000 g/mol, the melt viscosity is excessively lowered, so that the dispersibility of other components included in the composition for shoe members is extremely reduced, and in some cases, phase separation between the polyolefin and the other components Alternatively, layer separation may occur. On the other hand, when the weight average molecular weight of the polyolefin is more than 100,000 g/mol, melt viscosity increases and processability is lowered, which may cause non-uniform kneading during kneading.

The molecular weight distribution (Mw/Mn) of the polyolefin may be 3-7. If the molecular weight distribution of the polyolefin is less than 3, the dispersibility with the other components may be lowered, so that the physical properties of the manufactured shoe member may become non-uniform for each part and region, and if it exceeds 7, the mechanical properties of the shoe member may be reduced.

The polyolefin is, for example, one selected from the group consisting of polyethylene, polypropylene, polybutylene, polymethylpentene, ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and combinations or copolymers of two or more thereof. may be, preferably, polyethylene, more preferably, low-density polyethylene (LDPE), but may be, but is not limited thereto. Since the low-density polyethylene has a melting point of about 100 to 120° C., compatibility and compatibility with the ethylene vinyl acetate can be properly secured.

The content of the crystalline polymer in the main resin may be 5 to 30% by weight. If the content of the crystalline polymer in the main resin is less than 5% by weight, it is difficult to sustain the physical properties of the shoe member for more than a certain period of time, and if it exceeds 30% by weight, the rebound elasticity of the shoe member and its restoring force may be reduced.

When the composition for the shoe member is prepared including only ethylene vinyl acetate, weight reduction may be realized, but durability and mechanical properties may be lowered to increase the defect rate of the shoe as well as reduce the user's fit and comfort. However, when a large amount of metal oxide is included, compatibility with the main resin and workability are reduced, and as the content of metal components increases, the weight of the shoe member becomes heavy, which may also act as a factor to reduce the feeling of wearing of the user. there is.

Therefore, by including a small amount of metal oxide in the first and second ethylene vinyl acetate and the crystalline polymer having different monomer compositions, it is possible to finally realize light weight of the shoe and improve the durability and recovery of the shoe member. .

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 member is less than 1 part by weight, durability and mechanical properties of the shoe may be reduced, and if it exceeds 10 parts by weight, a large amount of the metal oxide in the composition may be included to reduce the lightness of the shoe. there is.

The metal oxide may include zinc oxide, titanium oxide, or a combination thereof.

The zinc oxide may be included and dispersed in the main resin to control the crosslinking rate and promote foaming. The titanium oxide may be included in the composition for a shoe member together with the zinc oxide to further promote crosslinking and foaming.

The composition for the shoe member may include a lubricant, and the lubricant may be, for example, stearic acid, but is not limited thereto. The stearic acid may serve to uniformly disperse the composition for the shoe member. Specifically, the stearic acid may be included in the composition for shoe members to finely pulverize large particles or aggregated particles in the composition into smaller particles and uniformly disperse the particles to prevent agglomeration of the particles.

The content 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 dispersion effect may be weak, and if it is more than 5 parts by weight, the viscosity of the composition for shoe members may be excessively lowered, thereby reducing workability.

The composition for the shoe member may include a foaming agent. The blowing agent may include, for example, one selected from the group consisting of azodicarbonamide, dinitrosopentamethyltetraamine, azobisisobutylnitrile, p-toluenesulfonylhydrazide, and combinations of two or more thereof. and, preferably, may be azodicarbonamide, but is not limited thereto.

The content of the foaming agent may be 1 to 10 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, the lightness may be reduced, and if it is more than 10 parts by weight, the durability of the shoe member may be reduced.

The composition for a shoe member 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-butylperoxylaurylate, t-dibutylperoxymaleic acid, t-butylhydroperoxide, 2,5-dimethyl-2,5-di(t- It may be one selected from the group consisting of butylperoxy)nucleic acid, di-t-butylperoxide and 1,3-bis(t-butylperoxyisopropylene)benzene, and combinations of two or more thereof, preferably, diku It may be mil peroxide, but is not limited thereto.

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 member may be reduced, and if it exceeds 5 parts by weight, the flexibility and restoring force of the shoe member may be reduced.

The crosslinking aid may serve as a crosslinking accelerator for accelerating 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 include one selected from the group consisting of ene glycol acrylate, butylene glycol dimethacrylate, metal-acrylate, metal-methacrylate, and a combination of two or more thereof, preferably triallyl cyanurate. may be, but 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 parts by weight, the durability and mechanical properties of the shoe member may be reduced, and if it exceeds 2 parts by weight, the flexibility and restoring force of the shoe member may be reduced.

Another aspect of the present invention provides a method of manufacturing a shoe member comprising the step of foam molding a composition for a shoe member.

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

In the press method, the composition for a shoe member is separately foamed and expanded, manufactured in a sheet form using a press, cut to a size required for manufacturing, put in a press mold, pressurized at high temperature and high pressure, and cooled to manufacture a shoe member. . In addition, the injection method can manufacture the shoe member through injection molding in which a composition for a shoe member is prepared as a compound in the form of a pellet through an extruder, and the composition is put into an injection mold to perform crosslinking and foaming while maintaining a heating state.

The method of manufacturing the shoe member may include mixing the composition for the shoe member before including the step of foam molding. The composition for the shoe member contains a metal oxide, a lubricant, and a foaming agent, based on 100 parts by weight of a main resin including a first ethylene vinyl acetate, a second ethylene vinyl acetate having a monomer composition different from that of the first ethylene vinyl acetate, and a crystalline polymer. and other additives may be added to and mixed in a mixer, and the mixer may be a kneader, a ban-bury mixer, or an open roll mill, but is limited thereto not.

Mixing in the kneader may be performed at 50 to 100 ° C. If the temperature is less than 50 ° C, uniform mixing may be difficult, and if it exceeds 100 ° C, additives such as a crosslinking agent and a foaming agent may be decomposed, thereby reducing 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" refer to a screw type extruder having one and two screws, respectively.

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

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

On the other hand, the length: diameter ratio of the extruder may be 25 to 50: 1. The "length:diameter ratio" of the extruder means the ratio of the length (L) to the diameter (diameter, D) of the screw, which is one of the factors determining the extrusion performance of the extruder. In general, the larger the value of the “length:diameter ratio” of the screw, the better the kneading effect and product quality, and the reduction of the deviation of the extrusion amount. can be adjusted differently.

If the ratio of the length: diameter of the extruder is less than 25: 1, the kneading effect of the required level cannot be realized, and if it exceeds 50: 1, the size of the extruder and the capacity of the driving motor are affected, thereby reducing the process efficiency.

In addition, the driving speed of the extruder may be 50 to 500rpm. The driving speed of the extruder means the rotation 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 realized, and if it exceeds 500 rpm, the rotation of the motor compared to the number of rotations of the screw Due to the remarkably large number, excessive load may be applied to the motor and reduction gear to cause damage.

In addition, another aspect of the present invention provides a shoe member manufactured by foaming the composition for a shoe member.

The shoe member may satisfy the following conditions. In addition, the hardness (Asker, C) of the shoe member may be 45 or more.

<expression>

B/A ≥ 0.9

In the above formula, A is the rebound elasticity (%) measured immediately after manufacturing the shoe member, which is 40 or more, and B is the rebound elasticity (%) measured 7 days after manufacturing the shoe member.

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

Example 1

50% by weight of a first ethylenevinylacetate (EVA1) containing 28% by weight of vinyl acetate, 45% by weight of a second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate, and low density polyethylene (LDPE, Tm=110°C) ) With respect to 100 parts by weight of the main resin consisting of 5% by weight, 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 1 part by weight of dicumyl peroxide, 1 part by weight of triallyl cyanurate, 6 parts by weight of azodicarbonamide The mixture was prepared by adding it to the steamer and kneading at 70° C. for 10 minutes.

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

Example 2

The main resin is 45% by weight of first ethylenevinylacetate (EVA1) containing 28% by weight of vinyl acetate, 45% by weight of second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate, and low density polyethylene (LDPE, Tm) =110° C.) A shoe midsole was manufactured in the same manner as in Example 1, except that it was changed to include 10% by weight.

Example 3

The main resin is 43% by weight of first ethylenevinylacetate (EVA1) containing 28% by weight of vinyl acetate, 42% by weight of second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate, and low-density polyethylene (LDPE, Tm) =110° C.) A shoe midsole was manufactured in the same manner as in Example 1, except that it was changed to include 15% by weight.

Example 4

The main resin is 40% by weight of first ethylenevinylacetate (EVA1) containing 28% by weight of vinyl acetate, 30% by weight of second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate, and low-density polyethylene (LDPE, Tm) =110 ° C.) A shoe midsole was manufactured in the same manner as in Example 1, except that it was changed to include 30% by weight.

Comparative Example 1

Except for changing the main resin to include 50% by weight of the first ethylenevinyl acetate (EVA1) containing 28% by weight of vinyl acetate, and 50% by weight of the second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate Then, a shoe midsole was manufactured in the same manner as in Example 1.

Comparative Example 2

The main resin is 50% by weight of a first ethylenevinyl acetate (EVA1) containing 28% by weight of vinyl acetate, 46% by weight of a second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate, and low density polyethylene (LDPE, Tm) =110° C.) A shoe midsole was manufactured in the same manner as in Example 1, except that it was changed to include 4% by weight.

Comparative Example 3

The main resin is 35% by weight of first ethylenevinylacetate (EVA1) containing 28% by weight of vinyl acetate, 33% by weight of second ethylenevinylacetate (EVA2) containing 18% by weight of vinyl acetate, and low density polyethylene (LDPE, Tm) =110° C.) A shoe midsole was manufactured in the same manner as in Example 1, except that it was changed to include 32% by weight.

Compositions of the mixtures according to Examples and Comparative Examples are shown in Table 1 below.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 EVA1 50 45 43 40 50 50 35 EVA2 45 45 42 30 50 46 33 LDPE 5 10 15 30 0 4 32

(Unit: % by weight)

Experimental Example: Evaluation of physical properties of shoe midsole

The physical properties of the shoe midsoles manufactured according to the Examples and Comparative Examples were evaluated, and the results are shown in Table 2 below. The property evaluation method is as follows.

-Hardness (Asker, C): Measured using an Asker C-type hardness tester according to KS M 6660

-Specific gravity (g/cc): Measured 5 times according to KS M 6660 using an automatic specific gravity measuring device of Ueshima and expressed as an average value

-Repulsion elasticity (%): Measured using Daesung Science's rebound resilience tester according to KS M ISO 8307

division Hardness importance Rebound elasticity immediately after manufacturing (A) Rebound elasticity after 7 days (B) B/A Example 1 46 0.2 44.3 40.5 0.914 Example 2 48 0.2 42.2 39.0 0.924 Example 3 50 0.2 40.5 37.8 0.933 Example 4 53 0.2 40.1 38.1 0.950 Comparative Example 1 44 0.2 43.8 38.4 0.877 Comparative Example 2 45 0.2 41.9 37.5 0.895 Comparative Example 3 55 0.2 36.3 35.8 0.985

Referring to Table 2, the shoe midsoles (Examples 1 to 4) prepared by foaming a composition containing two types of ethylene vinyl acetate having different monomer compositions and a certain amount of a crystalline polymer (low density polyethylene) had lower hardness. 45 or more, and the rebound elasticity immediately after manufacturing is 40% or more, and it can be seen that durability, restoring force, and cushioning characteristics are implemented in a balanced way. In particular, in the case of the shoe midsoles according to Examples 1 to 4, the ratio of the rebound elasticity measured after 7 days to the rebound elasticity measured immediately after manufacturing was 0.9 or more, and the change in the rebound elasticity over time was relatively small, and accordingly, the It is expected that the restoring force given to the midsole of the city shoe can be maintained for a long time without deterioration.

On the other hand, the shoe midsole (Comparative Examples 1 and 2) prepared by foaming a composition containing a relatively small amount of crystalline polymer (low density polyethylene) has a relatively high content of ethylene vinyl acetate in the main resin, so the rebound elasticity immediately after manufacturing is It was measured to be 40% or more, but it appears that the rebound elasticity decreased to less than 90% immediately after manufacturing after 7 days, and in general, considering that the rebound elasticity deterioration after that is further accelerated, the restoring force of the shoe member and the shoe including the same expected to decline significantly.

In addition, the shoe midsole (Comparative Example 3) prepared by foaming a composition containing a relatively excessive amount of crystalline polymer (low density polyethylene) had a relatively high content of crystalline polymer in the main resin, so the rebound elasticity immediately after manufacturing was 40% It was measured to be less than, so it was difficult to give a suitable restoring force to the shoe member during the manufacturing stage, and as an excess of crystalline polymer was mixed, the createability and processability during mixing and foaming were significantly reduced.

The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into 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 dispersed form, and likewise components described as distributed may also 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 their equivalents should be construed as being included in the scope of the present invention.

Claims (10)

With respect to 100 parts by weight of the main resin comprising the first ethylene vinyl acetate, the second ethylene vinyl acetate having a monomer composition different from that of the first ethylene vinyl acetate, and a crystalline polymer,
1 to 10 parts by weight of a metal oxide, 0.1 to 5 parts by weight of a lubricant, and 1 to 10 parts by weight of a foaming agent,
A composition for the absence of shoes. According to claim 1,
The content of the crystalline polymer in the main resin is 5 to 30% by weight,
A composition for the absence of shoes. According to claim 1,
The content of vinyl acetate in the first ethylene vinyl acetate is 20 to 30% by weight,
A composition for the absence of shoes. According to claim 1,
The content of vinyl acetate in the second ethylene vinyl acetate is 5 to 20% by weight,
A composition for the absence of shoes. According to claim 1,
The content of the first ethylene vinyl acetate in the main resin is 40 to 90% by weight,
A composition for the absence of shoes. According to claim 1,
The crystalline polymer comprises one selected from the group consisting of polyolefin, polyester, polycarbonate, polyamide, polyimide, and combinations of two or more thereof,
A composition for the absence of shoes. According to claim 1,
The metal oxide comprises zinc oxide, titanium oxide, or a combination thereof,
A composition for the absence of shoes. According to claim 1,
The composition for the shoe member further comprises a crosslinking agent and a crosslinking aid,
A composition for the absence of shoes. Claims 1 to 8, prepared by foaming the composition for a shoe member according to any one of claims 1 to 8,
absence of shoes. 10. The method of claim 9,
The shoe member satisfies the following conditions,
Absence of shoes:
<expression>
B/A ≥ 0.9
In the above formula,
A is the rebound elasticity (%) measured immediately after manufacturing the shoe member, and is 40 or more,
B is the rebound elasticity (%) measured 7 days after manufacturing the shoe member.