KR100828908B1 - Health shoes and midsole manufacturing method with midsole structure of triple structure - Google Patents

Abstract

In the present invention, in the health shoes having the midsole structure of the triple structure, in particular in the construction of the midsole constituting the bottom of the shoe, the nylon injection piece layer is wrapped with a polyurethane layer, and the polyurethane layer is directly injected EVA (EVA) (Ethylene vinyl acetate), ethylene vinyl acetate) It is inserted and bonded to the inside of the resin layer, and the bottom layer is composed of a rubber material to provide a shoe with excellent cushioning and strength, and relates to a health shoe having a midsole structure of a triple structure. In that,

The structure of the midsole is characterized by consisting of a hard nylon injection piece layer, a polyurethane layer covering the outer shell of the nylon injection piece layer, and an EVA layer covering the outer shell of the polyurethane layer;

The manufacturing method of the midsole consists of manufacturing the EVA resin by the injection molding method, inserting the hard nylon injection piece into the polyurethane, and inserting the polyurethane wrapped around the nylon injection piece into the injection EVA resin and then bonding it. This is a feature.

Description

A shoe and midsole manufacturing method having 3-state midsole organizing

The present invention relates to a health shoe having a midsole structure of a triple structure, and in particular, in forming a midsole constituting the bottom of a shoe, the nylon injection piece layer is wrapped with a polyurethane layer, and the polyurethane layer is directly injected with EVA ( It is attached to the inside of EVA (ethylene vinyl acetate) and ethylene vinyl acetate resin layer, and the bottom layer is made of rubber material to provide shoes with excellent cushioning and strength. It is about.

In general, the movement of the foot on the ground during walking is a three-step process, in which the left and right feet repeat the landing step by the heel, the center moving step from the heel to the heel, and the step of the heel pushing off the ground.

In conventional shoes, the shape of the heel is formed at a right angle to the ground, and in the case of shoes, a sharp edge is formed on the heel so that this edge touches the ground first during the landing stage. Because of its linear shape, the impact at the time of landing is large, and the movement to the center movement stage, which is the next stage of landing, is performed at once, so that a sudden impact force is transmitted to each joint of the leg and body as well as the ankle joint, resulting in poor landing feeling and walking. It becomes unnatural.

1 is an overall configuration diagram of a conventional shoe,

A conventional shoe 5 consists of an upper 1, an insole 2, a midsole 3 and an outsole 4.

However, not all shoes 5 are provided with the midsole 3 and the outsole 4, and may have only any part depending on the use and function of each shoe 5. That is, the upper 1 is directly coupled to the upper portion of the outsole 4 to manufacture the shoe 5, or the upper 1 is directly coupled to the midsole 3 without the outsole 4 to form the shoe 5. It may be, which will vary depending on the function and use of the shoe (1).

And, according to the structure and material of the midsole (3) and the outsole (4) and upper (1) constituting the sole, various kinds of shoes (5) are produced, for example, in order to be used as jogging shoes 3) and the outsole (4) and the upper (1) is made of a material that is shock-absorbing and lightweight material, and in addition to the midsole (3) in the shoe (5) that requires a function for wear resistance and anti-slip Outsole (4) attached to the bottom of the) is to produce a shoe (5) using a rubber material. As described above, in the shoe 1, the price and price of the shoe 5 as well as the type and function of the shoe 5 are determined according to how the structures, shapes, and materials of the midsole 3 and the outsole 4 forming the sole are configured. Will be.

The outsole 4 and the midsole 3 forming the sole as described above are usually manufactured separately so that the outsole 4 is attached to the bottom of the midsole 3. This is because the soles of the soles and the midsoles of the soles play different roles in the shoe.

That is, the outsole (4) is mainly made of rubber or non-foamed polyurethane because the material is configured to perform such a function because the main function is to prevent the slip and landing wear due to long time use. On the contrary, the midsole 3 is made of ethylene vinyl acetate or a foamed polyurethane material of a relatively light material because the main purpose is to absorb shock and lighten the weight of the shoe.

However, in the related art, since the midsole is simply made of a foamed polyurethane material, there is a limitation in the cushioning feeling, and in addition, when only the polyurethane is used, there is a problem in that hydrolysis occurs and deformation occurs when used for a long time.

In addition, since there is no means to firmly support the inside of the midsole there was a problem that is easily broken when used for a long time.

The present invention is to solve the above problems, it is to provide a shoe with a hard nylon injection-piece layer wrapped in a polyurethane layer and inserting it again inside the EVA resin layer to increase the cushioning feeling and overall strength of the midsole. There is this.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

As a means for achieving the above object,

The present invention is a conventional shoe composed of an upper, an insole, a midsole and an outsole, wherein the midsole includes a hard nylon injection-piece layer; A polyurethane layer surrounding the outer shell of the nylon injection piece layer; It is characterized by consisting of an EVA (EVA) layer surrounding the outer shell of the polyurethane layer.

In addition, the manufacturing method includes the steps of preparing a solid EVA resin by injecting a liquid EVA resin in the mold by the injection method and then foaming in the mold; Inserting the rigid nylon injection piece into the polyurethane; Polyurethane wrapped in nylon injection piece is inserted into EVA resin and then bonded.

In addition, the manufacturing process of the eva resin, ethylene vinyl acetate copolymer, ethylene octene copolymer, and ethylene butene copolymer by modifying the step (SVA) to form an EVA material (S10); Forming a liquid YV compound by combining a crosslinking agent, a foaming agent, and other additives with the EVA material (S20); After the EVA compound is injected into the upper and lower molds while the mold is closed, the internal temperature of the screw is maintained at 50-120 ° C. and the mold temperature is 130-200 ° C. to crosslink for 3-20 minutes. Step S30; It is characterized by consisting of the step (S40) to take out the product after the upper and lower molds are opened and foamed momentarily.

The present invention inserts a rigid nylon injection piece into a polyurethane mold and inserts it back into the EVA resin to produce a shoe midsole, thus uniformly distributing the landing impact in the landing and centering stages and discontinuous in the ankle joint, leg and body. It does not cause shock.

In addition, the direct injection Ebara adopts the secondary molding operation method, it has excellent resilience and can prevent the wrinkle of the product.

In addition, the outer part is a light and cushioning injection EVA is commercially well used to prevent 100% of hydrolysis, which is a problem of polyurethane, and is about 2/3 lighter than polyurethane.

In addition, the second injection molding process of the primary injection piece nylon with polyurethane is performed on the inside to wrap the hard rigid nylon injection part with a soft polyurethane mold, which has a perfect effect on the injection EVA adhesive surface and cushioning.

In addition, the ultra-lightweight, double-insert structure has excellent grip.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Figure 2 is a plan view showing the bonding of the polyurethane layer and nylon injection piece layer of the present invention.

Figure 3 is a vertical cross-sectional view showing a polyurethane layer and a nylon injection piece layer of the present invention.

Figure 4 is a plan view showing the bonding of the EVA resin layer, polyurethane layer and nylon injection piece layer of the present invention.

Figure 5 is a vertical cross-sectional view showing the EVA resin layer, polyurethane layer and nylon injection piece layer of the present invention,

6 is a flow chart of the EVA resin layer manufacturing step of the present invention, Figures 2 and 3 shows that the nylon injection piece layer is embedded in the polyurethane layer, Figures 4 and 5 in the EVA resin layer polyurethane The layer and the nylon injection-piece layer are incorporated to show that the midsole of the present invention is completed.

The shoe midsole of the present invention consists of three layers.

That is, it consists of a nylon injection piece layer 10 inserted in the center, a polyurethane layer 20 surrounding the circumference of the nylon injection piece layer, and an EVA resin layer 30 surrounding the polyurethane layer.

Unlike the rubber and polyurethane materials, the EVA resin layer 30 applied to the present invention is light, easy to process, and relatively inexpensive. In particular, the EVA resin layer is a shock absorbing part, which is manufactured by secondary molding a sponge crosslinked / foamed EVA.

And the method of manufacturing a midsole using the said three layers is as follows.

Primary work;

EVA resin is injected into the mold specially manufactured by the injection method and then foamed in the mold. At this time, since the volume change occurs severely through foaming, if the mixing ratio, quantity, press temperature, etc. of raw materials are not accurate, the midsole within the tolerance range Hard to get.

In other words, the midsole mold with the midsole forming portion is located on the top of the outsole mold, and the midsole is made of foam-molded EVA resin with the center portion open, and the press is pressed to produce the midsole. At this time, the pressure applied to the press is 50 to 70kgf / cm ³ , the crosslinking for 3 to 20 minutes while maintaining the mold temperature at 130 to 200 degrees.

The material of the mold is made of light and hard aluminum, and the high temperature transmission and rapid cooling are performed quickly so that the manufacturing work of the midsole is made rust.

These molds are generally used for the production of the foamed EVA midsole, so there is no need for an iron mold for manufacturing a separate midsole.

Secondary work;

The injection molding layer 10 is inserted into the polyurethane mold 20 by using hard nylon.

Tertiary work;

Liquid injection of polyurethane and hard Nile injection pieces into the mold by foam injection molding, and then produced by direct injection injection EVA resin layer 30 is adhesively inserted.

The process of the first working step is summarized through a flow chart as follows.

Forming an EVA (EVA) material by modifying the ethylene vinyl acetate copolymer, the ethylene octene copolymer and the ethylene butene copolymer (S10);

Forming a liquid EVA compound by combining a crosslinking agent, a foaming agent, and other additives with the EVA material (S20);

After the EVA compound is injected into the upper and lower molds while the mold is closed, the internal temperature of the screw is maintained at 50-120 ° C. and the mold temperature is 130-200 ° C. to crosslink for 3-20 minutes. Step S30;

The upper and lower molds are momentarily opened and foamed, and the product is taken out (S40).

Hereinafter, the eva resin used in the present invention will be described.

Polyethylene resin-based polar copolymers include EVA (ethylene vinyl acetate) resin, EMA and EEA [ethylene methyl (ethyl) acrylate] resin with excellent heat resistance, and E (M) AA [ethylene (metha) acrylic acid] resin with excellent adhesion to aluminum foil. Ionomer resin made by polymerizing EAA or EMAA with metal ions, and EVOH (ethylene vinyl alcohol) resin with excellent gas barrier properties. These resins are widely used in the field of packaging materials, films, adhesives, and compounds due to their unique properties, and the introduction, properties, and uses of the double EVA resins are introduced.

Looking at the manufacturing method of the EVA resin applied to the present invention.

EVA resin is a copolymer produced by polymerizing ethylene monomer and vinyl acetate monomer (VAM) in a high pressure reactor producing low density polyethylene (LDPE) to produce EVA resin by adding VAM as desired.

EVA resins are divided into high pressure polymerization, solution pressure and emulsion polymerization depending on the preparation method, and their shape varies according to the preparation method. The EVA resin produced through high pressure and medium pressure is in the form of pellets in a solid state and the maximum VA content that can be produced is about 40% or less depending on the conditions of the reactor.

Looking at the characteristics of the EVA resin applied to the present invention are as follows.

EVA resin has unique characteristics different from LDPE resin by copolymerizing VAM, unlike LDPE resin polymerized with ethylene only. LDPE is one of the most chemically resistant products among the existing polymer materials, but EVA has a polar group, and the chemical resistance decreases as the VA content increases. It has excellent resistance to most acids, alkalis and organic / inorganic chemicals, but weak chemicals to halogens and aromatics, chlorinated hydrocarbon compounds and animal and vegetable oils. Unlike LDPE, the hygroscopicity increases as the VA content increases due to the introduction of a polar group, and the gas barrier property decreases due to the decrease in crystallinity due to the bulky VAM compared to ethylene. In addition, the odor is generated in the EVA polymerized by the acetic acid odor of VAM itself, which is an obstacle to expanding the use.

Looking at the thermal properties of the EVA resin applied to the present invention.

Unlike LDPE, EVA resin has the advantage of low temperature sealing properties when applied to packaging materials due to its low melting point. However, due to the low thermal stability of VAM itself, EVA resin has inferior characteristics that VAM is decomposed at lower temperatures than LDPE.

In other words, unlike LDPE, EVA loses weight at around 366 ° C because acetic acid (CH3COOH) is decomposed in VAM in EVA. Negative phenomena such as deterioration of resin properties, increased odor and color change due to denitrification are increased. In addition, as the VA content is increased, the decomposition temperature of EVA is also lowered, so that the heat resistance is further reduced. In the air atmosphere in which oxygen is present, the decomposition temperature of VAM decreases rapidly, and decomposition may occur at 200 to 250 ° C.

Looking at the use of the EVA resin applied to the present invention are as follows.

As described above, EVA resin, unlike LDPE, is transparent and has excellent low temperature heat sealability and crosslinking properties, and thus is used as a raw material for shoe sponges, agricultural films, thermal materials for thermal films, and hot-melt adhesives. In the present invention, the EVA resin is used as a cushion material for shoes.

Looking at the polyurethane manufacturing method applied to the present invention.

First, Polyurethane means that the Urethane Bond is an addition polymerization of an alcohol having an active hydroxyl group (-OH) and an isocyanate having an isocyanate group (-N = C = O). It is formed when heat of reaction is generated by an addition polymerization reaction. In addition, isocyanates having at least one isocyanate group (NCO Group) and alcohols having at least one hydroxyl group (-OH) are called polyfunctional groups, while the functional group dissipates high-temperature heat under appropriate conditions. It produces a compound having the structure of -NHCoo-] n, which is called a urethane bond, and more than 1000 molecules are bonded to a polyurethane.

Side Reaction of Polyurethane

Polyurea reaction; Isocyanate reacted with polyfunctional alcohols simultaneously reacts with water (H ₂ O) to produce urea and carbon dioxide (CO 2).

Allophanate & Biuret Reaction Crosslinking Reaction in which the produced hydrogen remaining in urethane and urea reacts with excess isocyanate under appropriate conditions to produce allophanate and biuret. Proceed.

Uretidinedion & Isocyanurate Reaction; Isocyanates react under a basic catalyst to form uretidinedione, Dimer, and isocyanurate, Trimer. Dimer is produced from Aromatic Isocyanate. For example, Monomeric MDI, 4, 4'-diphenylmethane diisocyanate, is slowly dimerized at room temperature and insoluble at high temperatures. Polymer) material is formed.

Isocyanurate is produced by heating aliphatic and aromatic isocyanates, which is accelerated by a basic catalyst.

Polyurethane Raw Materials

Isocyanate

Phosgene in diphenylmethane diamine (MDA) produced by condensation of aniline and formaldehyde (4,4'-Diphenylmethane diisocyanate (MDI)) MDI is obtained by treating (COCl2) with (Phosgenation). The reaction product contains several kinds of isomers and polynuclears, but upon purification it is separated into Pure MDI (or Crude MDI). Monomeric MDI is a white solid at room temperature, so it is used by modifying it to liquid such as carbodiimide-modified MDI or uretonimine-modified MDI.

Polymeric MDI is a liquid at room temperature, and the average number of functional groups in the product is 2.3 ~ 3.0 level and is characterized by viscosity, reactivity and NCO% content. The viscosity of the product depends on the average molecular weight and the NCO% content of the product.

Monomeric MDI is mainly used in non-foamed polyurethanes such as spandex, synthetic elastomers, coatings and sealants.

Polymeric MDI is widely used in the manufacture of foamed polyurethane foams, mainly for refrigerators, containers, sprays, building insulation and automobile interiors.

Nylon injection piece of the present invention uses a synthetic resin material, the outer shape and the curved surface of the midsole is formed in the form of a plate shape. When walking, the anterior part with a relatively large bending angle forms a plurality of slits that are opened to the anterior end at a certain position in the anterior portion and divides them into moisture to facilitate the bending action of the front heel.

Accordingly, it is desirable to restore the original shape of the sole, which preserves the original shape of the sole and shoes well, and has a high frequency of bending and elongation during walking, and increases the stability of the walking because the shape of the sole is kept elastic and firm.

In addition, since the repulsive force is added by the restoring force in the detachment stage, the front gum is pushed in the walking direction, so that the light walking is performed and the walking efficiency is high.

In the present invention, the cushioning action is improved due to the polyurethane material inserted into the EVA resin, so that no space for a separate cushion is required, and a separate member such as an air bag does not need to be installed.

In addition, in the past, there is a built-in spring or a liquid bag instead of the air bag, but also difficult to manufacture as well as difficult to manufacture its own weight, it is difficult to put to practical use of the present invention, the poly inside the EVA resin Since urethane cushions and EVA resin is lightweight, it is possible to provide shoes with excellent cushioning while providing lightweight shoes.

After all, the present invention has a restoring power while absorbing the impact when the light weight is applied to reduce the weight of the entire shoe, and the polyurethane is inserted into the EVA foam used to expand and expand to prevent discoloration and environmental pollution And, by inserting an injection piece with a hard nile inside the polyurethane, it provides a firm yet cushioned shoes.

1 is a general shoe configuration.

Figure 2 is a plan view showing the bonding of the polyurethane layer and nylon injection piece layer of the present invention.

Figure 3 is a vertical cross-sectional view showing a polyurethane layer and a nylon injection piece layer of the present invention.

Figure 4 is a plan view showing the bonding of the EVA resin layer, polyurethane layer and nylon injection piece layer of the present invention.

Figure 5 is a vertical cross-sectional view showing the EVA resin layer, polyurethane layer and nylon injection piece layer of the present invention.

Figure 6 is a flowchart of the EVA resin layer manufacturing step of the present invention.

Explanation of symbols on the main parts of the drawings

10: Nylon injection piece layer

20: polyurethane layer

30: Eva resin layer

Claims (3)

In a conventional shoe (5) consisting of an upper (1), an insole (2), a midsole (3) and an outsole (4), The midsole, A hard nylon injection piece layer; A polyurethane layer surrounding the outer shell of the nylon injection piece layer; Health shoes having a midsole structure of a triple structure, characterized in that the EVA (EVA) layer surrounding the outer shell of the polyurethane layer. Preparing a solid EVA resin by injecting a liquid EVA resin into the mold by an injection method and then foaming the mold in a mold; Inserting the rigid nylon injection piece into the polyurethane; Method of manufacturing a midsole of the triple structure, characterized in that consisting of the step of adhering the polyurethane wrapped around the nylon injection piece into the EVA resin. The method of claim 2, The EVA resin production process, Ethylene vinyl acetate copolymer, ethylene octene copolymer, and ethylene butene copolymer modified to form an EVA (EVA) material (S10); Forming a liquid YV compound by combining a crosslinking agent, a foaming agent, and other additives with the EVA material (S20); After the EVA compound is injected into the upper and lower molds while the mold is closed, the internal temperature of the screw is maintained at 50-120 ° C. and the mold temperature is 130-200 ° C. for crosslinking for 3-20 minutes. Step S30; Method of manufacturing a midsole of a triple structure, characterized in that the step of taking out the product (S40) after the upper and lower molds are opened and foamed momentarily.

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