WO2016137153A1 - Rubber composition for bonding shoe sole and shoe sole manufacturing method - Google Patents

Abstract

Provided are a rubber composition for bonding a shoe sole and a shoe sole manufacturing method, the composition being for integrating an outsole and midsole, and comprising a mixture of a vulcanizing agent, and a polymer substrate which contains rubber and an ethylene copolymer having a melting point of 35-90°C, and the shoe sole manufacturing method using the rubber composition and comprising the steps of: laminating, on an outsole sheet, a bonding sheet manufactured by mixing the vulcanizing agent with the polymer substrate which contains rubber and an ethylene copolymer having a melting point of 35-90°C; and manufacturing the outsole sheet having the bonding sheet laminated thereon and a foam midsole preform into a shoe sole having an integrated outsole and midsole by using a shoe sole mold.

Description

Rubber composition for shoe bonding and method for manufacturing shoe sole

The technology disclosed herein relates to a rubber composition for shoe bonding and a method of manufacturing a shoe sole using the same.

Shoes are made of rubber soles made of natural rubber and synthetic rubber, which are soles on the ground (hereinafter referred to as 'outsoles') that touch the ground for lightweighting, and midsoles between rubber soles and uppers (hereinafter referred to as 'midsoles') It is common to use ethylene copolymer foam such as EVA foam having good cushioning.

The outsole is manufactured by mixing and vulcanizing silica (SiO ₂ ) and a vulcanizing agent as a reinforcing material to natural rubber and synthetic rubber to realize wear resistance and slip resistance, and the ethylene copolymer foam foam midsole is an ethylene copolymer such as EVA. It is usually prepared by combining the crosslinking agent and the blowing agent in the following four methods:

First, the compound is foamed at a suitable magnification and then molded into a midsole through a process of skiving-cutting-buffing.

This method has a simple and inexpensive advantage, but the midsole surface shape is simple and the appearance is not beautiful due to the exposure of cells of the foam foam, so it is applied to some low-cost products.

Second, the compound is pelletized by an extruder, injection and heating pressurized in a mold provided in the injection foaming machine to perform crosslinking foaming, and then the product is taken out of the mold and manufactured into a midsole having a predetermined foaming ratio of about 150 to 170%. .

This method has the advantage of being relatively simple and inexpensive. However, since the product is foamed in the mold, it may be difficult to obtain a clean product in appearance because of poor dimensional stability or poor surface condition of the product.

Third, according to the Phylon process, first prepare a midsole molded article (hereinafter referred to as 'midsol preform') through the first method, and then put the midsol preform of 1.52 times the mold content into the final product mold for 10 to 20 minutes. Heat pressurization (hereinafter referred to as 'heating pressurization') and then reduced to 15 ~ 30 ℃ pressurization for 10 to 20 minutes (hereinafter referred to as 'cooling pressurization') and the product is completely cooled and demolded.

This method has the same size as the product and the mold, so it is possible to obtain high-quality products with a beautiful appearance, but the manufacturing process is cumbersome and has disadvantages such as factory area and cost.

Fourth, according to the CMP-Phylon process, which is a modification of the third method, the compound is placed in a mold and cross-linked and foamed under warming pressure to obtain a compression molded preform (CMP) that is 1.5 to 2 times larger than the content of the midsole mold. After manufacturing, put 1.5 ~ 2 times more midsole preform (CMP) into the final product mold, heat and pressurize for 10-20 minutes, reduce the temperature to 15-30 ℃, pressurize for 10-20 minutes, and then completely cool the product. How to demould.

In this method, the product and mold have the same size, so that a high-quality product with a beautiful appearance can be obtained, and the manufacturing process is not only shorter than the third Phylon process, but also the skiving-cutting-buffing process is omitted, so that the material loss is also lower than that of the third Phylon process. It is now becoming commonplace on the basis of 20-30% savings.

The resulting midsole cannot be used as a shoe sole by itself, and is then used as a finished window by adhering on an outsole using an adhesive or the like. The midsole according to the first process described above is a final process at room temperature buffing, and the midsole according to the second process. The silver may be foamed when demolded from the mold, so it may not be possible to replace the bonding process.

On the other hand, in the third process and the fourth process, when the product is demolded, the size of the product and the mold are the same, so that the vulcanized outsole is inserted in the lower part of the press molding die for the midsole, and the midsole preform that is 1.5 to 2.0 times larger than the mold content is laminated. And by molding, it will be possible to reduce the manpower and cost burden due to such an adhesion process, for example, according to Korea Patent Registration No. 1214673 and the like, after mounting the outsole to the mold and then laminated with an adhesive film such as epoxy and EVA foam And a method of demolding after cooling through heating pressurization and cooling pressurization. However, this method also requires two or more adhesive films, and also has disadvantages of a long process of heating and cooling, and energy consumption.

Accordingly, the present inventors focus on the novel rubber composition for shoe bonding as a related technology that can be substituted for the adhesive process using the adhesive between the outsole and the midsole, or the adhesive using two or more adhesive films instead of the adhesive. It was completed.

That is, one object of the technology disclosed herein includes an ethylene copolymer having a specific melting point range to form a bridge structure between the outsole and the midsole without further heating using the press mold extraction temperature of the midsole. It is to provide a rubber composition for shoe bonding.

Another object of the technology disclosed in the present specification is to use the rubber composition for the sole bonding to perform the process of bonding the outsole and the midsole without additional heating of the final shoe product mold, to provide a method of manufacturing a shoe sole with improved adhesive strength and heat resistance There is.

According to one aspect of the technology disclosed herein,

A composition for integrating an outsole and a midsole, comprising: a polymer substrate including an ethylene copolymer and a rubber having a melting point of 35 to 90 ° C; And it provides a rubber composition for shoe bonding comprising a mixture of vulcanizing agent.

According to another aspect of the technology disclosed herein,

A polymer substrate including an ethylene copolymer having a melting point of 35 ° C. to 90 ° C. and a rubber; And laminating a bonding sheet prepared by mixing the vulcanizing agent on the outsole sheet; It provides a shoe sole manufacturing method comprising the step of manufacturing the outsole sheet and the foamed midsole preform (CMP) is laminated to the bonding sheet using a sole mold sole sole and the midsole outsole.

According to another aspect of the technology disclosed herein,

The ethylene copolymer in the bonding sheet manufactured by the above-described manufacturing method and melted by the mold take-out surface high temperature of the foamed midsole preform (CMP) forms a bridge structure between the outsole sheet and the foamed midsole and provides an integrated shoe sole. .

According to the technique disclosed herein, the outsole is used by using a rubber composition for shoe bonding comprising an ethylene copolymer having a specific melting point range so as to be melted by the mold take-out surface high temperature of the midsole preform to form a bridge structure between the outsole and the midsole. Not only does not omit the bonding process of the midsole, and furthermore, there is an effect of omitting the heating process of the final product mold and providing a method of manufacturing a shoe sole with improved adhesive strength and heat resistance.

Hereinafter, the technique disclosed in the present specification will be described in more detail.

Conventional shoe manufacturing processes include an adhesive process using an adhesive between the outsole and the midsole and a heating process in the final product mold. The omission of these processes increases the need for enormous energy savings and shortening of the processing time.

Therefore, according to the technology disclosed in the present specification, not only does not omit the bonding process using the adhesive between the outsole and the midsole, but also omits the heating process of the final product mold, and has the effect of producing a shoe sole with improved adhesive strength and heat resistance, Provided is a novel rubber composition for shoe bonding, which is melted by a compression mold ejection temperature and can form a bridge structure between an outsole and a midsole.

A rubber composition for shoe bonding according to an embodiment of the present disclosure, a composition for integrating an outsole and a midsole, an ethylene copolymer having a melting point of 35 to 90 ° C and a polymer including rubber materials; And mixtures of vulcanizing agents. The ethylene copolymer has a low price and low hardness and excellent miscibility with a rubber substrate compared to general ethylene polymer, and melts when taken out of the midsole preform compression molding mold to form an adhesive bridge between the outsole and the midsole. The rubber base material can increase the wear resistance and at the same time give high elasticity and maintain the physical properties of the final shoe product.

In particular, the melting point of the ethylene copolymer may be in the range that can be melted at the extraction surface temperature to suit the role of the adhesive bridge between the outsole and the midsole, for example, may be 35 to 90 ℃, or 38 to 88 ℃. It is possible to prevent the deformation and shrinkage of the sole according to the change of the external environment (particularly the temperature) within the above range, and also to melt at a surface temperature of 120 ~ 150 ℃ of the foamed midsole preform taken out from the midsole preform compression molding mold, sufficient adhesive bridge effect Can be provided.

For reference, the outside air temperature during the hottest summer may rise to around 35 ° C. When the sole is exposed therein, when the melting point of the ethylene copolymer is less than 35 ° C, the ethylene polymer contained in the rubber composition for bonding is melted and shoes Adhesion may deteriorate while wearing. In addition, when the melting point of the ethylene copolymer exceeds 90 ℃, the foamed preform with a surface temperature of 120 ~ 150 ℃ taken out from the press molding die to melt the ethylene copolymer contained on the upper surface of the outsole placed on the bottom of the midsole mold Insufficient at may cause weak adhesion and may be difficult to commercialize.

The melting point refers to the melting point peak temperature measured by differential scanning calorimetry (DSC) thermal analysis, unless otherwise specified.

The rubber composition for shoe bonding, for example, the weight ratio of the ethylene copolymer and the rubber may be 2: 8 to 8: 2, 3: 7 to 7: 3, or 4: 6 to 6: 4, within this range The adhesive strength between the bonding sheet and the outsole sheet obtained from the rubber composition for shoe bonding at, and the adhesive strength and heat resistance of the outsole sheet and the bonding sheet and the foamed preform can be provided significantly improved.

For reference, insufficient rubber content may result in poor adhesion between the outsole sheet and the bonding sheet obtained from the bonding rubber composition, and insufficient content of ethylene copolymer may result in poor adhesion between the bonding sheet and the midsole.

The ethylene copolymers include, for example, i) ethylene, and ii) C ₃ -C ₁₀ alpha olefins, C ₁ -C ₁₂ alkyl esters of C ₃ -C ₂₀ monocarboxylic acids, unsaturated C ₃ -C ₂₀ mono or dicarboxylic acids, It may be a copolymer of at least one ethylenically unsaturated monomer selected from the group consisting of anhydrides of unsaturated C ₄ -C ₈ dicarboxylic acids and vinyl esters of saturated C ₂ -C ₁₈ carboxylic acids or ionomers thereof.

Specific examples of the ethylene copolymers include ethylene vinyl acetate, (Ethylene Vinylacetate, EVA), ethylene butyl acrylate (Ethylene Butylacrylate, EBA), ethylene methyl acrylate (Ethylene Methylacrylate, EMA), ethylene ethyl acrylate (Ethylene Ethylacrylate, EEA). ), Ethylene methyl methacrylate (Ethylene Methylmethacrylate, EMMA), ethylene butene copolymer (Ethylene Butene Copolymer, EB-Co), ethylene octene copolymer (Ethylene Octene Copolymer, EO-CO) and the like.

In the ethylene copolymers, preferably, ethylene comprises the major mole fraction of the total polymer, usually ethylene comprises at least about 50 mole% of the total polymer. More preferably, ethylene comprises at least about 60 mol%, at least about 70 mol%, or at least about 80 mol%.

In terms of high elasticity, the ethylene copolymer may be a copolymer of ethylene and an alpha olefin. Here, the alpha olefin is an olefin having 2 or more carbon atoms having a double bond at the terminal. Substantial remainder except for ethylene in the total ethylene alphaolefin copolymer comprises at least one other comonomer which is preferably an alpha olefin having at least 3 carbon atoms. Particularly commercialized and in view of availability, the alpha olefin is preferably butene, hexene or octene. For example, for ethylene octene copolymers, preferred compositions have an ethylene content of at least about 80 mole percent of the total polymer, and an octene content of about 10 to about 15 mole percent, preferably about 15 to about 20 mole percent, of the total polymer. Include.

The ethylene and alpha-olefin copolymer may be random copolymers or block copolymers. Commercialized products include Dow Chemical's Engage and Infuse, Mitsui's Tafmer, Exxon Mobile's Exact, LG Chemical's LG-POE, and others, particularly for the low cost process of the technology disclosed herein. Coalescence is preferred. For the ethylene random copolymer, the ethylene content may be about 60 mol% to about 99.5 mol%, in some embodiments about 80 mol% to about 99 mol%, and in some embodiments about 85 mol% to about 98 mol% have. Likewise, the alpha-olefin content may range from about 0.5 mol% to about 40 mol%, in some embodiments from about 1 mol% to about 20 mol%, and in some embodiments, from about 2 mol% to about 15 mol%. The distribution of alpha-olefin comonomers is typically random and uniform over the different molecular weight fractions forming the ethylene copolymer.

The rubber may be selected, for example, from natural rubber, isoprene rubber, butadiene rubber, and styrene-butadiene rubber. The natural rubber may be general natural rubber or modified natural rubber. The general natural rubber may be used as long as it is known as natural rubber, and the origin and the like are not limited. The natural rubber is polyisoprene and contains cis-1,4-polyisoprene as a main component, but may also include trans-1,4-polyisoprene depending on the required properties. Therefore, the natural rubber includes, in addition to the natural rubber containing cis-1,4-polyisoprene as a main agent, for example, a natural containing trans-1,4-isoprene as a main agent such as a balata, which is a kind of rubber of South American sapotagua. Rubber may also be included. The modified natural rubber means a modified or refined general natural rubber. For example, the modified natural rubber may include epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), hydrogenated natural rubber, and the like. The natural rubber is not limited to any properties such as crepe rubber, sheet rubber, and skim rubber.

Specific examples of the rubber include, for example, at least one selected from i) styrene-butadiene rubber, and ii) high cis 1,4-isoprene rubber, and high cis 1,4-butadiene rubber. (high cis) rubber.

As a specific example, the weight ratio of the i) styrene-butadiene rubber, and ii) the high sheath rubber may be 4: 6 to 6: 4, or 4.5: 5.5 to 5.5: 4.5, to increase the injection processability within this range At the same time, it can be selected according to the type of raw materials used under conditions that give high elasticity and maintain the properties of the final shoe product . The high cis refers to a cis 1,4 content in the rubber of 95% or more, or 97% or more, unless otherwise specified, and may be excellent in workability and wear resistance within this range.

As another example, the styrene-butadiene rubber may have a Mooney viscosity (ML _{1 + 4} 100) of 45 to 55, and the high cis 1,4-isoprene rubber may have a Mooney viscosity (ML _{1 + 4} 100) of 80 to It may be 90, the high sheath 1.4-butadiene rubber may have a Mooney viscosity (ML _{1 + 4} 100) of 40 to 50. The Mooney viscosity refers to the viscosity of the unvulcanized rubber measured by the Mooney viscometer, and is usually expressed as ML _{1 + 4} (100) by measuring the value of 4 minutes after starting the rotor at 1 minute of preheating at 100. Done.

The rubber composition for bonding according to one embodiment of the technology disclosed herein contains a vulcanizing agent, wherein the vulcanizing agent is an additive for vulcanizing the rubber in the presence of the ethylene copolymer. Through the vulcanization process, the rubber substrate is crosslinked and dispersed as fine particles of micro-gel in the ethylene copolymer resin matrix.

The vulcanizing agent may be a sulfur or sulfur compound, and examples of the sulfur compound include sulfur dichloride, morpholine disulfide, polysulfide, tetramethylthiuram disulfide, and dimethyl dithiocarbamate selenium. (selenium dimethyl dithiocarbamate), 2- (4'-morpholinodithio) benzothiazole (2- (4'-morpholinodithio) benzothiazole), and the like. The vulcanizing agent may be included in an amount of 0.1 to 5.0 parts by weight, 0.1 to 3.0 parts by weight, or 0.3 to 1.7 parts by weight based on 100 parts by weight of the polymer substrate.

The rubber composition for bonding according to an embodiment of the present disclosure further contains a vulcanization accelerator, a softening agent such as stearic acid or ethylenebisstearamid, and a crosslinking aid such as zinc oxide, if necessary, within a range that does not adversely affect the reaction. Can be. For example, with respect to 100 parts by weight of the polymer substrate, the vulcanization accelerator may be included in the range of 0.1 to 3.0 parts by weight, or 0.2 to 0.8 parts by weight, the softener is It may be included in the range 0.1 to 3 parts by weight, or 0.1 to 2.5 parts by weight, and the crosslinking aid may be further included in the range of 0.5 to 8 parts by weight, or 0.6 to 4.4 parts by weight.

Method for manufacturing a shoe sole using a rubber composition for bonding according to an embodiment of the present disclosure can be prepared in the following manner. First, as a composition for bonding, a polymer substrate containing an ethylene copolymer and rubber having a melting point of 35 to 90 ℃; And the bonding sheet produced by mixing the vulcanizing agent on the outsole sheet. Next, the outsole sheet and the foamed midsole preform in which the bonding sheet is laminated may be provided as a shoe sole in which the outsole and the midsole are integrated using the sole mold.

The thickness of the outsole sheet and the bonding sheet may be, for example, a thickness ratio of 70:30 to 95: 5, or a thickness ratio of 75:25 to 90:10.

The step of laminating the bonding sheet on the outsole sheet, for example, can be performed for 10 to 20 minutes under a temperature condition of 150 ~ 160 ℃, it can provide an effective laminated, even integrated structure within this range.

The expansion ratio (linear expansion ratio) of the foamed midsole preform may be 170 to 190%. In addition, when the foamed midsole preform is taken out from the midsole molding die (compression molding die), the surface temperature is, for example, 120 to 150 캜, or 120 to 145 캜, in which the melting point contained in the rubber composition for bonding is 35 to 90 캜. It is preferable because the copolymer can be melted effectively.

The outsole sheet in which the bonding sheet is laminated may be heated to 50 to 150 ° C. in advance to maximize melting of the ethylene copolymer in the bonding sheet, thereby performing an efficient bridge structure.

Then, the outsole sheet and the foamed midsole preform in which the bonding sheet is laminated may be sequentially laminated to the sole mold, pressurized for a short time at room temperature, and demolded to provide an outsole and a midsole integrated sole.

Specifically, the step of manufacturing the outsole and the midsole integrated sole, the outsole sheet is laminated to the bonding sheet on the bottom of the sole mold, the surface temperature is 120 ~ immediately after taking out from the compression molding mold on the top of the sole mold The foamed midsole preform may be placed at 150 ° C., pressurized at room temperature for 3 to 10 minutes, and then demolded. In particular, according to the technology embodied herein, the pressurization process at room temperature for only a short time, such as 3 to 10 minutes, or 5 to 6 minutes at room temperature for cooling and then pressurizing after heating for the coupling between the outsole and the midsole in the sole mold in the prior art It may further provide advantages that can be manufactured.

The composition for the outsole sheet and the composition for the foamed midsole preform may be appropriately selected as long as they are known in the art. For example, the composition for the outsole sheet may include a vulcanizing agent such as an emulsifying or emulsifying compound in 100 parts by weight of a rubber base. 0.1 to 5.0 parts by weight may be included, the outsole sheet by mixing the composition for the outsole sheet in an open mill or the like and vulcanized in a mold under conventional vulcanization conditions, for example, 150 to 160 ℃ for 5 to 10 minutes. It can manufacture.

The rubber base material may be selected from, for example, one or more kinds of natural rubber and synthetic rubber. Specific examples thereof include a natural rubber and a synthetic rubber having a weight ratio of 10:90 to 90:10, or 20:80 to 80:20. It may be in the weight ratio range. In particular, the synthetic rubber may be a high cis 1,4-butadiene rubber, high cis 1,4-butadiene having a Mooney Viscosity (ML _{1 + 4} 100) 40 to 50 Rubber can be used.

The composition for the outsole sheet is a reinforcing agent, such as silica, carbon black, if necessary; Softeners such as stearic acid and ethylenebisstearamide; Rubber aids such as polyethylene glycol; Vulcanization accelerators; Active agent; Pigments and the like may further be included within the range not adversely affecting the reaction. For example, the composition for the outsole sheet is vulcanized in the range of 5 to 80 parts by weight of the reinforcing agent, in the range of 0.5 to 10 parts by weight of the softener, and in the range of 0.5 to 10 parts by weight of the rubber aid, based on 100 parts by weight of the rubber substrate. The accelerator may be included in the range of 0.5 to 3 parts by weight.

The foamed midsole preform composition may be a foamed composition including 1 to 15 parts by weight, or 1 to 10 parts by weight of an ethylene copolymer and a blowing agent such as azodicarbonamide based on 100 parts by weight of the ethylene copolymer. The foamed midsole preform composition may be mixed in an open mill or the like, placed in a compression molding die (CMP mold), and foamed under warming pressure to prepare a foamed midsole preform in a compression molding manner.

The ethylene copolymers include, for example, i) ethylene, and ii) C ₃ -C ₁₀ alpha olefins, C ₁ -C ₁₂ alkyl esters of C ₃ -C ₂₀ monocarboxylic acids, unsaturated C ₃ -C ₂₀ mono or dicarboxylic acids, It may be an unsaturated C ₄ -C ₈ dicarboxylic acid anhydrides and saturated C ₂ copolymer of ethylenically unsaturated monomers at least one member selected from the group consisting of vinyl esters of -C ₁₈ carboxylic acid or an ionomer (ionomer) of the copolymer.

Specific examples of the ethylene copolymers include ethylene vinyl acetate, (Ethylene Vinylacetate, EVA), ethylene butyl acrylate (Ethylene Butylacrylate, EBA), ethylene methyl acrylate (Ethylene Methylacrylate, EMA), ethylene ethyl acrylate (Ethylene Ethylacrylate, EEA), ethylene methyl methacrylate (Ethylene Methylmethacrylate, EMMA), ethylene butene copolymer (Ethylene Butene Copolymer, EB-Co), ethylene octene copolymer (Ethylene Octene Copolymer, EO-Co) and the like.

As another example of the ethylene copolymer, ethylene and vinyl acetate may be ethylene vinyl acetate having a weight ratio of 50:50 to 85:15 or a weight ratio of 60:40 to 80:20.

The foamed midsole preform composition may further be a foamed composition including 0.1 to 5 parts by weight, or 0.5 to 3 parts by weight of a crosslinking agent such as dicumyl peroxide based on 100 parts by weight of the ethylene copolymer.

The sole according to the embodiment of the present disclosure is manufactured by the above-described manufacturing method, and the ethylene copolymer in the bonding sheet melted by the mold ejection-surface high temperature of the foamed midsole preform is formed between the outsole sheet and the foamed midsole. It may be to form a bridge structure and have an integrated structure.

A shoe sole according to an embodiment of the present disclosure provides improved adhesion even without the heating process and manufactured without applying a separate adhesive film or bonding process, for example, the outsole sheet and the bonding sheet. an in-between adhesive strength 5.0~6.0 kg / cm ² range, and at the same time the bonding sheet and the foamed midsole between the adhesive strength is 4.0~5.0 kg / cm ² range can be tomorrow.

Hereinafter, the technology disclosed herein will be described through various embodiments, but the technical spirit of the technology disclosed herein is not limited to the following embodiments.

EXAMPLE

<Used raw material>

Natural Rubber-1: SMR-L (Standard Malaysian Rubber).

SBR1502 : Styrene-butadiene rubber containing 22.5-24.5 weight% of styrene monomer, 4.5-6.75 weight% of organic acid, and having a Mooney viscosity (ML _{1 + 4} 100) of 45-55.

IR2200 : high cis 1,4-isoprene rubber having a Mooney viscosity (ML _{1 + 4} 100) of 82.

BR1208 : high cis 1,4-butadiene rubber having a Mooney viscosity (ML _{1 + 4} 100) of 40 to 45.

Polymer-1: Engage 7467 (DOW, Ethylene Butene Copolymer, DSC Melting Point: 34 ° C).

Polymer-2: Engage 8842 (DOW, Ethylene Octene Copolymer, DSC Melting Point: 38 ℃)

Polymer-3: ELVAX 460 (Dupont, Ethylene Vinyl Acetate Copolymer, DSC Melting Point: 88 ℃)

Polymer-4: LDPE 5321 (Hanizing agent, LDPE, DSC Melting Point: 109 ° C)

Polymer-5: LLDPE 3120 (Hanizing agent, LLDPE, DSC Melting Point: 122 ° C)

Polymer-6: HDPE 3392 (Hanizing agent, HDPE, DSC Melting Point: 134 ° C).

<Shoe sole manufacturing including a bonding sheet (Examples 1-5, Comparative Examples 1-4)>

1) Bonding Sheet Manufacturing :

30 parts by weight of natural rubber SMR-L, 70 parts by weight of synthetic rubber BR1208, 1 part by weight of stearic acid, 5 parts by weight of zinc oxide, 40 parts by weight of silica (SiO2), 2 parts by weight of polyethylene glycol, 2 parts by weight of sulfur, a vulcanization accelerator (promoter) M) 1.5 parts by weight were mixed in an open mill to prepare an outsole sheet having a thickness of 4.0 mm.

According to the composition shown in Table 1 below, a polymer base of ethylene copolymer and rubber is blended in a kneader with a capacity of 1 L, and the kneader chamber temperature is raised to a temperature higher than the DSC melting point of the ethylene (co) polymer for 5 minutes. Mixed. After mixing, 1.0 parts by weight of sulfur as a vulcanizing agent, 0.5 to 1.0 parts by weight of accelerator M as a vulcanization accelerator, 1.0 parts by weight of stearic acid as a softening agent and 2.5 parts by weight of zinc oxide as a crosslinking aid were added after mixing for 1 minute. After further mixing, the reaction was terminated, and a total of nine bonding sheets having a thickness of 1.0 mm were prepared.

For reference, numbers indicating the content of each component in Table 1 is parts by weight.

division	Example 1	Comparative Example 1	Example 2	Comparative Example 2	Comparative Example 3	Comparative Example 4	Example 3	Example 4	Example 5
SBR1502	50	50	50	50	50	50			20
IR2200							50		15
BR1208								50	15
Polymer-1		50
Polymer-2	50
Polymer-3			50				50	50	50
Polymer-4				50
Polymer-5					50
Polymer-6						50

2) Manufacture outsole sheet with laminated bonding sheet :

The outsole sheet obtained through the above item 1) is placed at the bottom of a mold having a volume of 100x200x5 mm, the bonding sheet is laminated on the top, and heated and pressurized at 160 ° C. for 10 minutes, followed by demolding to form a bonded sheet having a size of 100x200x5 mm. The prepared outsole sheet.

3) Foamed midsole preform manufacture:

100 parts by weight of EVA (VA 21wt%), 1 part by weight of stearic acid, 2 parts by weight of zinc oxide, 0.9 parts by weight of crosslinking agent DCP, 4.0 parts by weight of foaming agent ADCA are mixed in an open mill and placed in a press mold (CMP mold) Foaming under 160 ° C./100 kg / cm ² ) yielded a foamed midsole preform having a foaming ratio (linear expansion ratio) of 190%, 100 × ²⁰⁰ × ²⁰ mm, and the surface temperature was measured by means of an infrared thermometer immediately after extraction from the pressing die. Confirmed.

4) Manufacture of outsole-midsole integrated molded products:

1) Laminated foamed midsole preform with a surface temperature of 125 ° C. at the top while placing one of each of the 9 kinds of vulcanized outsole sheets on which a 100x200x5mm bonding sheet is laminated at the bottom of the mold 100x200x15mm. The mold was sealed and held at room temperature for 5 minutes while being pressurized and demolded to obtain a finished shoe sole in which an outsole-midsole of 100 × 200 × 15 mm was integrated.

The physical properties of the finished shoe sole were measured according to the following test items, and the physical property test results are shown in Table 2 below.

<Test item>

One) Outsole Seat and Bonding Adhesion strength between sheets : Before laminating the bonding sheet on the outsole sheet, the bonded portion between the outsole sheet and the bonding sheet was separated with a knife and then the adhesive strength was measured using an Instron Tester. For reference, if the adhesive strength is more than 3.0kg / cm ² is good, if less than 3.0kg / cm ² is determined to be poor.

2) Adhesion strength between the bonding sheet and the foamed midsole : The bonding strength between the bonding sheet and the foamed midsole was separated by a knife on the foamed midsole preform in which the bonding sheet was laminated, and then measured using an Instron Tester. For reference, if the adhesive strength is more than 3.0kg / cm ² is good, if less than 3.0kg / cm ² is determined to be poor.

3) Heat resistance: Cut out sole with integrated sole and midsole to 20mm width, open outsole and midsole adhesive surface with outsole, hang the midsole on the upper clip and hang the 1Kg weight on the outsole. . If there is no change in the adhesive surface after 24 hours, it is considered good. In addition, the poor adhesion from the beginning is not the value of the experiment was marked as non-adhesive.

division	Example 1	Comparative Example 1	Example 2	Comparative Example 2	Comparative Example 3	Comparative Example 4	Example 3	Example 4	Example 5
Adhesion strength between outsole sheet and bonding sheet (kg / cm 2 )	5.0	5.0	6.0	5.5	5.5	5.5	5.0	4.5	4.5
Adhesive strength between the bonding sheet and foamed midsole (kg / cm 2 )	4.0	4.0	4.5	0.7	0.6	0.5	4.5	4.5	4.5
Heat resistance	Good	Bad	Good	Non-adhesive	Non-adhesive	Non-adhesive	Good	Good	Good

As shown in Table 2, the polymer substrate including the ethylene copolymer and rubber having a melting point in the range of 35 ~ 90 ℃; According to the soles prepared according to Examples 1 to 5 using the rubber composition for the sole bonding comprising a mixture of vulcanizing agents, the adhesive strength between the outsole sheet and the bonding sheet, the adhesive strength between the bonding sheet and the foamed midsole, and heat resistance All improved results.

On the other hand, according to the shoe sole prepared according to Comparative Example 1 using a rubber composition for the sole bonding comprising an ethylene copolymer having a melting point range of less than 35 ℃, the adhesive strength between the outsole sheet and the bonding sheet is improved, but the bonding sheet and the foamed midsole It was confirmed that the adhesive strength between the liver and the heat resistance was poor, respectively.

Additional Experimental Examples 1 to 3

In addition, a shoe sole manufactured by changing the composition of the bonding rubber composition for manufacturing the bonding sheet as described in Table 3 below, and a general sole manufactured by a bonding process between the outsole and the midsole without a bonding sheet, Physical properties were measured in the same manner as in Table 2 above, and summarized in Table 4. For reference, numbers representing the contents of each component in Table 3 are parts by weight.

division	Additional Experimental Example 1	Additional Experimental Example 2	Additional Experiment 3
SBR1502	10	90	-
IR2200			-
BR1208			-
Polymer-1			-
Polymer-2			-
Polymer-3	90	10	-
Polymer-4			-
Polymer-5			-
Polymer-6			-
brimstone	0.2	1.8	-
Accelerator M	0.1	0.9	-
Stearic acid	1.0	1.0	-
Zinc oxide	0.5	4.5	-

division	Additional Experimental Example 1	Additional Experimental Example 2	Additional Experiment 3
Adhesion strength between outsole sheet and bonding sheet (kg / cm 2 )	1.0	8.0	-
Bond strength between bonding sheet and foamed midsole (kg / cm 2 )	5.0	0.5	-
Heat resistance	Non-adhesive	Non-adhesive	Good

From the results of Table 4, the sole product of the technology disclosed herein can be replaced by the adhesive strength, heat resistance according to the composition constituting the bonding sheet, even in the general shoe soles omission between the outsole and the midsole adhesion process equivalent heat resistance characteristics There is an advantage to providing.

Claims (13)

1. A composition for integrating an outsole and a midsole, comprising: a polymer substrate including an ethylene copolymer and a rubber having a melting point of 35 to 90 ° C; And a mixture of vulcanizing agents.
2. According to claim 1,

   The ethylene copolymers are i) ethylene, and ii) C ₃ -C ₁₀ alpha olefins, C ₁ -C ₁₂ alkyl esters of C ₃ -C ₂₀ monocarboxylic acids, unsaturated C ₃ -C ₂₀ mono or dicarboxylic acids, unsaturated C ₄ A rubber composition for shoe bonding, which is a copolymer of at least one ethylenically unsaturated monomer selected from anhydrides of -C ₈ dicarboxylic acids and vinyl esters of saturated C ₂ -C ₁₈ carboxylic acids or is an ionomer of the copolymer.
3. According to claim 1,

   The rubber is a rubber composition for the sole bonding is selected from one or more of natural rubber, isoprene rubber, butadiene rubber and styrene-butadiene rubber.
4. According to claim 1,

   A rubber composition for shoe bonding, wherein the weight ratio of the ethylene copolymer and the rubber is 2: 8 to 8: 2.
5. According to claim 1,

   The rubber is at least one selected from i) styrene-butadiene rubber, and ii) high cis 1,4-isoprene rubber, and high cis 1,4-butadiene rubber. ) Rubber composition for shoe bonding made of rubber.
6. According to claim 1,

   Wherein the vulcanizing agent is a rubber composition for the sole bonding of sulfur or sulfur mixture.
7. According to claim 1,

   The vulcanizing agent is 0.1 to 5.0 parts by weight based on 100 parts by weight of the polymer substrate rubber composition for shoe bonding.
8. A polymer substrate including an ethylene copolymer having a melting point of 35 ° C. to 90 ° C. and a rubber; And laminating a bonding sheet prepared by mixing the vulcanizing agent on the outsole sheet; And

   And manufacturing the outsole sheet and the foamed midsole preform in which the bonding sheets are stacked into a shoe sole in which the outsole and the midsole are integrated by using a shoe mold.
9. The method of claim 8,

   The thickness of the outsole sheet and the bonding sheet is a manufacturing method of a shoe sole having a thickness ratio of 70:30 to 95: 5.
10. The method of claim 8,

    The step of laminating the bonding sheet on the outsole sheet is a manufacturing method of a shoe sole is performed for 10 to 20 minutes under a temperature condition of 150 ~ 160 ℃.
11. The method of claim 8,

    The step of manufacturing the outsole and the midsole integrated sole, the outsole sheet laminated the bonding sheet on the bottom of the sole mold, the surface temperature is 120 ~ 150 ℃ immediately after taking out from the compression mold on the top of the sole mold A method of manufacturing a shoe sole that is placed foamed midsole preform and pressurized at room temperature for 3 to 10 minutes and then demolded.
12. The ethylene copolymer in the bonding sheet manufactured by the manufacturing method according to any one of claims 8 to 11 and melted by the mold ejection-surface high temperature of the foamed midsole preform forms a bridge structure between the outsole sheet and the foamed midsole. Integrated shoe soles.
13. The method of claim 12,

    The outsole sheet and the bonding adhesive strength between the sheet and 5.0~6.0 kg / cm ^2, the bonding sheet and the foamed midsole between the adhesive strength is 4.0~5.0 kg / cm ² of the sole.