KR100662726B1 - A composition of transparent and high elastic polyolefins for shoes midsole and method for manufacturing of middle layer sole for shoes - Google Patents

Abstract

Provided are a polyolefin-based composition for a midsole which is excellent in transparency, elasticity, discoloration resistance, durability and adhesion, and a method for preparing a midsole by using the composition. The polyolefin-based composition comprises 0.01-5 parts by weight of an antioxidizing agent; 0.01-5 parts by weight of a UV stabilizer; 0.05-10 parts by weight of a crosslinking agent; 0.01-3 parts by weight of a co-crosslinking agent; and 0.05-5 parts by weight of an adhesion enhancer based on 100 parts by weight of a polyolefin-based copolymer base. Preferably the polyolefin-based copolymer is at least one selected from an ethylene-alpha -olefin copolymer and an ethylene-vinyl acetate copolymer; and the adhesion enhancer is at least one selected from an alkoxylated nonylphenol acrylate, a monofunctional acid ester, a trifunctional acid ester, a trifunctional acrylate ester and a trifunctional methacrylate ester.

Description

A composition of transparent and high elastic polyolefins for shoes midsole and Method for manufacturing of middle layer sole for shoes}

The present invention relates to a polyolefin-based composition for shoe soles having transparency and high elasticity, and to a method for manufacturing shoe soles using the same. More specifically, the present invention is based on a polyolefin-based copolymer, and includes an antioxidant, an ultraviolet stabilizer, and an adhesion promoter. The present invention relates to a polyolefin-based composition for shoe soles and a method for manufacturing a shoe sole using the same, characterized in that injection crosslinking is carried out by mixing a crosslinking agent, thereby providing excellent transparency and elasticity.

In general, when a person jumps and lands during a vigorous exercise, a maximum impact of 7.1 to 4.1 times as a weight is reported. It is known to have a greater impact force because it does not function. In addition, it is reported that the impact force generated when running rather than walking can reduce the impact force by about two thirds by wearing a suitable sports shoe using a shock absorber. Therefore, cushioning function that absorbs shock among the functionalities of sports shoes is very important and these cushioning functions are mainly expressed in the midsole of sports shoes.

As a cushioning material for sports shoes, the biodegradation of shoe sole foam of Korea Patent Publication No. 167140 (registered on Sep. 26, 1998) or 10-2005-87967 (published on September 1, 2005) The midsole is prepared by foaming an ethylene / vinylacetate copolymer composition as in the case of a shoe sole foam composition and a method for preparing the same, or Korea Patent Publication No. 10-2000-34796 (published on June 26, 2000) or Korean Patent Publication 10-2000-45063 (published on July 15, 2000), such as the polyurethane resin composition for the shoe midsole foamed to produce a midsole or sports shoes using special structures such as air bags in addition to these foams It has attracted the attention of consumers with various desires for consumption, and its excellence is recognized functionally.

As such, in the shoe industry, various changes are being sought in response to the consumption patterns and tastes of modern people, and research on functional and design elements is active. Therefore, the functional cushion material requires the application of a new material in addition to the foam used in the existing, and the application of the transparent material among them can be said to be very important as a means for imparting fashion to sports shoes because visual differentiation is possible. .

In general, polymeric materials are semi-crystalline and have some crystalline properties. Transparency is related to crystal size. Large crystals reduce the transparency. Generally, this effect is believed to be due to scattering and diffraction of incident light, and most polymeric materials with good transparency are mainly amorphous.

On the other hand, in the case of polymer blend systems, phase separation occurs when the polymers are not completely mixed at the molecular level, but when the separated phases are smaller than the wavelength of visible light, they do not impair transparency but when they interfere with the wavelength of visible light. It spawns and becomes opaque. In addition, the transparency of the polymer is partially obtained by using a filler of particles finer than the wavelength of visible light.

In this respect, the foam, which is mainly used as a shock absorber for shoe soles, contains bubbles inside, and the presence of such bubbles scatters light, making the application of the transparent material fundamentally impossible.

Meanwhile, transparent materials that are conventionally used in the shoe industry include vinyl chloride resin (PVC), styrene-based thermoplastic elastomers (styrenic TPE), and urethane-based thermoplastic elastomers (TPU). Among them, vinyl chloride resin contains chlorine (Cl) component, which is a gradual use regulation material due to environmental pollution during combustion and has a disadvantage of lack of elasticity. Styrene / butadiene / styrene block copolymer (SBS) and styrene / isoprene / styrene block copolymer (SIS) among styrene thermoplastic elastomers have disadvantages of poor discoloration resistance, heat resistance, and durability, and styrene has improved durability through hydrogenation reaction. / Ethylene / butylene / styrene block copolymer (SEBS) has the disadvantages of high price and poor resilience. In addition, the urethane-based thermoplastic elastomer has a disadvantage of high price and poor discoloration resistance.

Accordingly, the present invention has been made in order to solve the problems described above, by producing a midsole by injection cross-linking a polyolefin-based composition, which is based on a polyolefin copolymer and mixed with an antioxidant, a UV stabilizer and an adhesion promoter and a crosslinking agent. It is an object of the present invention to provide a polyolefin-based composition for shoe soles and a method for manufacturing shoe soles using the same, which are characterized by excellent transparency and elasticity.

And the present invention is a shoe midsole parts manufactured by the composition of the present invention as described above, by designing a polyolefin as a base material, excellent discoloration resistance and durability, and also required for application to the shoe midsole by the use of adhesion promoters Polyolefin-based composition for shoe soles, characterized in that not only exhibits excellent adhesive properties as well as general injection processing is possible in the injection molding machine commonly used for the production of foam midsoles in the shoe industry and Another object is to provide a method for manufacturing a shoe sole using the same.

The composition of the present invention for solving the above problems is 0.01 to 5 parts by weight of antioxidant, 0.01 to 5 parts by weight of UV stabilizer, 0.05 to 5 parts by weight of crosslinking agent with respect to 100 parts by weight of the polyolefin-based copolymer base in the polyolefin composition for footwear midsole 10 parts by weight, 0.01 to 3 parts by weight of crosslinking aid and 0.05 to 5 parts by weight of adhesion promoter.

The present invention relates to a polyolefin-based composition for shoe soles, which is based on a polyolefin copolymer and is injected crosslinked after mixing an antioxidant, a UV stabilizer, a crosslinking agent, and an adhesion promoter. The copolymer may be selected from ethylene / alpha olefin copolymer and ethylene / vinylacetate copolymer and used alone or in blend.

The ethylene / alpha olefin copolymer used as the substrate includes ethylene and copolymers of propylene (C3), butene (C4), hexene (C6) and octene (C8) as alpha olefins which are comonomers, and have a density of 0.86 to Select one or more of 0.90 and have a melt index (MI) of 0.5 to 10 as measured by ASTM D1238. At this time, if the density is less than 0.86, the hardness is too low and the heat resistance may be lowered. If the density exceeds 0.90, the elasticity is lowered and it is not suitable as a cushion material. In addition, when the melt index is less than 0.5, the flowability is poor, and processing and molding are difficult. When the melt index is more than 10, physical properties may be degraded.

In addition, the ethylene / vinylacetate copolymer used as the base material is copolymerized with ethylene and vinyl acetate as a comonomer, and it is preferable to use one or more of vinyl acetate content of 25 to 45% by weight. At this time, if the vinyl acetate content is less than 25% by weight, the transparency is lowered, which is not suitable. If the vinyl acetate content is more than 45% by weight, the hardness is too low and the heat resistance is not suitable.

Such antioxidants include 3,5-di-tert-butyl-4-hydroxy toluene, 2,4,6-tri tert-butylphenol, styrenated phenol, 4-hydroxy-methyl-2,6-di Tert-butylphenol, 2,5-di-tert-butylhydroquinone, cyclohexylphenol, butyl hydroxyanisole, 2,2'-methylene-bis (4-methyl-6 tert-butyl-phenol), 4,4'-isopropylidene bisphenol, 1,1,3-tris (2-ethyl-4-hydroxy-5-tert-butyl-phenol) butane, 1,3,5-tris-methyl-2,4 , 6-tris (3,5-di-tertbutyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxy-phenol) propylonate ] 1 to 5 parts by weight, preferably 0.02 to 1 part by weight, based on 100 parts by weight of one or more selected from methane can be used. If it is less than 0.01 weight part at this time, antioxidation effect is hard to expect, and when it exceeds 5 weight part, transparency will be reduced, and it is unpreferable.

Examples of the UV stabilizer include a benzophenone series (eg 2,4-dihydroxybenzophenone), a silyl acetate series (eg p-tert-butylphenyl salicylate), and a benzotriazole type (eg 2- ( 2'-hydroxy-3'-tert-butyl-5'-methylphenyl) 5-chlorobenzotriazole), acrylonitrile-based (e.g. 2-ethylhexyl-2-cyano-3,3'-diphenyl Acrylate), hindered amine-based (e.g., bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate) and selected from 0.01 or 5 to 100 parts by weight of the substrate. Parts by weight, preferably 0.02 to 2 parts by weight. If it is less than 0.01 weight part at this time, it is hard to expect the effect, and when it exceeds 5 weight part, transparency will fall, and it is unpreferable.

Generally, polymer blends made of such substrates can be crosslinked for physical properties, performance and durability, and these properties are directly related to the number and form of crosslinks formed during the crosslinking reaction.

As the crosslinking agent that may be used in the present invention, an organic peroxide crosslinking mechanism may be used.

In the organic peroxide crosslinking mechanism, the organic peroxide may be used in an amount of 0.05 to 10 parts by weight based on 100 parts by weight of the substrate, and if it is less than 0.05 parts by weight, sufficient crosslinking may not be achieved. have.

Examples of the crosslinking agent that can be used in the present invention include cyclohexanone peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxy laurate, t-butylperoxy acetate, and di-t-butyl as organic peroxides. Diperoxyphthalate, t-dibutyl peroxymaleic acid, t-butyl cumyl peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, dibenzoyl peroxide, dicumyl peroxide, 1,3-bis (t- Butylperoxyisopropyl) benzene, methylethylkeponperoxide, di- (2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5- (t-benzoylperoxy) hexane, 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 ) From diisopropylbenzene or the like or It can be used to select at least.

In addition, in the present invention, in order to shorten the molding time during peroxide crosslinking and to obtain an appropriate crosslinking structure, the crosslinking aid may be used in an amount of 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the substrate. If the amount used is less than 0.01 part by weight, it is difficult to obtain an appropriate crosslinked structure because of insufficient crosslinking promoting effect. If the amount is more than 3 parts by weight, it is not preferable because early crosslinking occurs or the molded product is easily broken.

The crosslinking aids are, for example, p-quinonedioxime, p, p-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine and trimethylolpropane-N, Peroxy crosslinking aids such as N'-m-phenylenedimaleimide; Divinylbenzene, triarylcyanurate (TAC) and triarylisocyanurate (TAIC); One or more polyfunctional vinyl monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and vinyl stearate can be selected and used. .

In addition, in the present invention, the adhesion promoter is used to improve the adhesion, and the adhesion promoter usable in the present invention includes alkoxylated nonylphenol acrylate, monofunctional acid ester, trifunctional acid ester, trifunctional acrylate ester, One or more of trifunctional methacrylate esters may be selected and 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the substrate. If the amount is less than 0.05 part by weight, the effect is difficult to expect, and if it exceeds 5 parts by weight, the adhesiveness of the composition is increased, and smooth processing is difficult.

Referring to the manufacturing process of the shoe midsole with transparency and high elasticity using the olefin composition for shoes made of the above composition components as follows.

First, a composition based on the polyolefin-based copolymer for shoe soles according to the present invention is prepared in a pellet form, and then injected into a closed mold using an injection molding machine to obtain a high temperature and high pressure of 100 to 200 ° C. and 50 to 200 kg / cm ² . Shoe midsole is manufactured by molding for 3 to 20 minutes.

In the production of the shoe midsole of the present invention, when the injection temperature is less than 100 ℃, injection pressure 50kg / cm ² or less than 3 minutes injection time is low temperature or low pressure or injection molding time is too short enough crosslinking does not occur. Because of this, there is a high possibility that the mechanical properties of the molded product may be degraded or defective products may occur, and even if the injection temperature is 200 ° C., the injection pressure is 200 kg / cm ² or the injection time exceeds 20 minutes, There exists a possibility that the mechanical properties of a molded object may fall.

Hereinafter, the present invention will be described in more detail based on the examples prepared in the configuration of Table 1, but the present invention is not limited to the examples.

Example 1

Ethylene / Alphaolefin Copolymer A (Tafmer DF640, Mitsui Chemicals) 45 wt%, Ethylene / Vinyl Acetate Copolymer A (Elbox 150, Dupont) 30 wt% and Ethylene / Vinyl Acetate Copolymer B (Elbox CM3326, DuPont ) 100 parts by weight of the substrate consisting of 25% by weight of 0.01 parts by weight of antioxidant, 0.01 parts by weight of UV stabilizer and 0.05 parts by weight of adhesion promoter were kneaded in a closed mixer at 100-120 ° C. for about 15 minutes. In a roll mill at 70 ° C. to 80 ° C., 1 part by weight of the crosslinking agent and 0.2 part by weight of the crosslinking aid were kneaded and then sufficiently kneaded to prepare pellets using an extruder. The pelletized kneaded product was aged at room temperature (23 ° C.) for at least 24 hours, and then injection-crosslinked at a mold temperature of 175 ° C. for 10 minutes using an injection machine to prepare a molded specimen having a thickness of 3 mm.

Example 2

Ethylene / Alphaolefin Copolymer A (Tafmer DF640, Mitsui Chemicals) 45 wt%, Ethylene / Vinyl Acetate Copolymer A (Elbox 150, Dupont) 30 wt% and Ethylene / Vinyl Acetate Copolymer B (Elbox CM3326, DuPont ) 1 part by weight of antioxidant, 1 part by weight of UV stabilizer and 1 part by weight of adhesion enhancer were kneaded in a closed mixer at 100-120 ° C. for about 15 minutes based on 100 parts by weight of the substrate made of 25% by weight, and then the surface temperature was 70 In a roll mill having a temperature of ˜80 ° C., 1 part by weight of the crosslinking agent and 0.2 part by weight of the crosslinking aid were added and kneaded sufficiently to prepare a molded product specimen in the same manner as in Example 1 below.

Example 3

Ethylene / Alphaolefin Copolymer A (Tafmer DF640, Mitsui Chemicals) 45 wt%, Ethylene / Vinyl Acetate Copolymer A (Elbox 150, Dupont) 30 wt% and Ethylene / Vinyl Acetate Copolymer B (Elbox CM3326, DuPont 5 parts by weight of antioxidant, 5 parts by weight of UV stabilizer and 5 parts by weight of adhesion enhancer were kneaded in a closed mixer at 100-120 ° C. for about 15 minutes based on 100 parts by weight of the substrate made of 25% by weight. In a roll mill having a temperature of ˜80 ° C., 1 part by weight of the crosslinking agent and 0.2 part by weight of the crosslinking aid were kneaded and then sufficiently kneaded to prepare a molded product specimen in the same manner as in Example 1 below.

Comparative Example 1

Styrene-based thermoplastic elastomer was injection molded at a mold temperature of 23 ° C. using a general plastic injection molding machine to prepare a molded specimen having a thickness of 3 mm.

Comparative Example 2

The urethane-based thermoplastic elastomer was injection molded at a mold temperature of 23 ° C. using a general plastic injection molding machine to prepare a molded specimen having a thickness of 3 mm.

Comparative Example 3

45 wt% ethylene / alphaolefin copolymer B (Tafmer DF140, Mitsui Chemicals), 30 wt% ethylene / vinylacetate copolymer A (Elbox 150, DuPont) and ethylene / vinylacetate copolymer B (Elbox CM3326, DuPont) ) 0.02 parts by weight of antioxidant and 0.03 parts by weight of UV stabilizer were kneaded in a closed mixer at 100-120 ° C. for about 15 minutes with respect to 100 parts by weight of the substrate made of 25% by weight in a roll mill having a surface temperature of 70-80 ° C. 1 part by weight of the crosslinking agent and 0.2 part by weight of the crosslinking aid were sufficiently kneaded with respect to 100 parts by weight of the substrate, and then a molded product specimen was prepared in the same manner as in Example 1 below.

                                                   (Unit: parts by weight) division Example Comparative example One 2 3 One 2 3 Ethylene / Alphaolefin Copolymer A ¹⁾ 45 45 45 - - - Ethylene / Alphaolefin Copolymer B ²⁾ - - - - - 45 Ethylene / Vinyl Acetate Copolymer A ³⁾ 30 30 30 - - 30 Ethylene / Vinyl Acetate Copolymer B ⁴⁾ 25 25 25 - - 25 Antioxidant ⁵⁾ 0.01 1.0 5.0 - - 0.01 UV stabilizer ⁶⁾ 0.01 1.0 5.0 - - 0.01 Adhesion Promoter ⁷⁾ 0.05 1.0 5.0 - - - Crosslinker ⁸⁾ 1.0 1.0 1.0 - - 1.0 Crosslinking aid ⁹⁾ 0.2 0.2 0.2 - - 0.2 Styrenic thermoplastic elastomer ¹⁰⁾ - - - 100 - - Urethane-based Thermoplastic Elastomer ¹¹⁾ - - - - 100 -  1) Mitsui Chemicals, Tafmer DF640 (density: 0.862) 2) Mitsui Chemicals, Tafmer DF140 (density: 0.905) 3) Dupont, Elvax 150 4) Dupont, Elvax CM3326 5) Shiba gauge, Irganox 1076 6) Shiba gauge, Chimassorb 944 7) Sartomer, SR9012 8) Japan Synthetic Oil, DCP 9) Sartomer, SR350 10) Kumho Petrochemical, KTR 601 11) Hosung Chemex, Neothane 5075A

Examples 1 to 3 and Comparative Examples 1 to 3 molded article prepared in 3mm by the following method to test the properties and the results are shown in [Table 2].

Physical properties unit Example Comparative example One 2 3 One 2 3 importance - 0.91 0.92 0.93 0.94 1.20 0.91 Hardness A type 66 67 68 74 75 66 Turbidity % 4 4 4 4 3 15 Resilience % 70 71 68 52 55 58 Adhesive strength kg / cm 2.8 2.7 2.8 2.4 2.3 2.3 Discoloration resistance Grade 5 5 5 3 3 5

1) Specific gravity

In accordance with KS M6519, the measurement was performed 5 times using a model DMA-3, an automatic specific gravity measurement apparatus of Ueshima Corporation, and the average value was taken.

2) hardness

According to ASTM D2240, it was measured using an Asker A type hardness tester.

3) Turbidity

In accordance with ASTM D1003 was measured using a turbidimeter manufactured by NIPPON DENSHOKU.

4) resilience

In accordance with ASTM D2632 it was measured using a resilience tester of Daesung Science.

5) Adhesive strength

The surface of the specimen was washed with MEK, and then applied with UV pretreatment D-PLY P-6-2 (Dynamic NSC) and dried at 60 ° C. for 3 minutes. The dried specimen was irradiated with UV under a condition of 0.56 J / cm 2, an aqueous adhesive AQUACE W-01 (Dynamic NSC) was applied, dried at 60 ° C. for 3 minutes, and pressed to prepare an adhesive specimen. After the prepared specimens were left at room temperature for 24 hours, the adhesive strength was measured by peeling at a tensile speed of 200 mm / min. Using Zwick's universal testing machine.

6) discoloration resistance

According to ASTM D1148, the specimens were tested using a Sunlamp tester manufactured by Shinhan Corporation, and the color change was measured using a grayscale (AATCC).

As shown in Table 2, in Comparative Example 3 using a high density (0.905) ethylene / alpha olefin copolymer as a substrate, the turbidity was poor and the resilience was poor, whereas the low density (0.862) ethylene / alpha olefin copolymer was described. In the case of Example 2 used as it can be seen that the turbidity is low, excellent transparency and excellent rebound elasticity.

And in the case of Examples 1 to 3 using the adhesion promoter showed excellent adhesive strength, in the case of Comparative Example 3 not using the adhesion promoter it can be seen that the adhesive strength is inferior.

In the case of the styrenic thermoplastic elastomer of Comparative Example 1 and the urethane-based thermoplastic elastomer of Comparative Example 2, not only the resilience was poor but also the discoloration resistance was poor compared with Examples 1 to 3.

That is, in the case of Examples 1 to 3, since it showed excellent properties in all items of transparency, resilience, adhesive strength, and discoloration resistance, it can be seen that it is suitable as a polyolefin-based composition for shoes having transparency and high elasticity.

As described above, the polyolefin-based composition for shoes having transparency and high elasticity of the present invention is based on a polyolefin-based copolymer, and an injection, cross-linking, and injection molding is produced after mixing an antioxidant, an ultraviolet stabilizer, an adhesion promoter, and a crosslinking agent. Therefore, not only can the shoe soles having excellent transparency and elasticity be manufactured, but also the polyolefin is designed based on the substrate, so that the discoloration resistance and durability are excellent, and thus the parts exposed to the outside can be applied. It can be applied to shoes in various forms because it has excellent adhesiveness, which is an essential characteristic for application as a part of shoe midsole.

In addition, since the polyolefin-based composition prepared as described above is excellent in transparency and elasticity, it is advantageous to be applicable to various uses such as sports goods, daily necessities, toys, etc. by providing a high-quality texture by incorporating various pigments.

Claims (8)

In the polyolefin-based composition for shoe midsole, It consists of 0.01-5 weight part of antioxidants, 0.01-5 weight part of ultraviolet stabilizers, 0.05-10 weight part of crosslinking agents, 0.01-3 weight part of crosslinking aids, and 0.05-5 weight part of adhesion promoters with respect to 100 weight part of polyolefin copolymer base materials. A polyolefin-based composition for shoe soles having transparency and high elasticity.       The method of claim 1, The polyolefin-based copolymer is a polyolefin-based composition for a shoe sole with transparency and high elasticity, characterized in that selected from ethylene / alpha olefin copolymer and ethylene / vinyl acetate copolymer used alone or blended.       The method of claim 2, Ethylene / alpha olefin copolymers include copolymers of propylene (C3), butene (C4), hexene (C6) and octene (C8), which are ethylene and alpha olefins as comonomers, have a density of 0.86-0.90 and ASTM D1238 A polyolefin-based composition for shoe soles having transparency and high elasticity, characterized by using one or more selected from the measured melt index (MI) of 0.5 to 10. The method of claim 2, The ethylene / vinylacetate copolymer is a polyolefin-based composition for a shoe sole having transparency and high elasticity, characterized in that the vinyl acetate is copolymerized with ethylene and a comonomer of 25 to 45% by weight. The method of claim 1, The adhesion promoter is one or more selected from alkoxylated nonylphenol acrylate, monofunctional acid ester, trifunctional acid ester, trifunctional acrylate ester, trifunctional methacrylate ester Polyolefin-based composition for shoe midsole with transparency and high elasticity. The method of claim 1, The crosslinking agent is cyclohexanone peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxylaurylate, t-butylperoxyacetate, di-t-butyldiperoxyphthalate, t-dibutyl peroxymaleic acid , t-butyl cumyl peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, dibenzoyl peroxide, dicumyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, methyl Ethyl kepon peroxide, di- (2,4-dichlorobenzoyl) peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5 -(t-benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5- (t One from -butyl peroxy) -3-hexyne, n-butyl-4,4-bis (t-butylperoxy) valerate, a, a'-bis (t-butylperoxy) diisopropylbenzene, and the like Or two or more selected and used Polyolefin-based composition for shoe midsoles with reputation and high elasticity. The method of claim 1, The crosslinking aid is p-quinonedioxime, p, p-dibenzoylquinonedioxime, N-methyl-N-4-dinitrosoaniline, nitrosobenzene, diphenylguanidine and trimethylolpropane-N, N'- peroxy crosslinking aids such as m-phenylenedimaleimide; Divinylbenzene, triarylcyanurate (TAC) and triarylisocyanurate (TAIC); Use of one or more of polyfunctional vinyl monomers such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and vinyl stearate A polyolefin-based composition for shoe soles having transparency and high elasticity. The composition based on the polyolefin-based copolymer for shoe soles according to claim 1 is prepared in pellet form, and then injected into a closed mold using an injection molding machine, under high temperature and high pressure of 100 to 200 ° C. and 50 to 200 kg / cm ² . Method of manufacturing a shoe midsole using a polyolefin-based composition for shoe midsole with transparency and high elasticity, characterized in that for 3 to 20 minutes to produce a shoe midsole having transparency and elasticity.