JP2020191986A - Sole - Google Patents

Abstract

To provide a sole comprising two layers of an outer sole and a midsole.SOLUTION: In a sole comprising two layers of an outer sole 1 and a midsole 2: a hardness (CType) of the outer sole is set at 62-68 degrees; a hardness (CType) of the midsole is set at 47-53 degrees; and a plurality of anti-slip ridges 3 in which each average depth (D) in a vertical direction from the road surface toward a lower bottom of the outer sole is 4 mm, and the maximum width (W) thereof is 4 mm are provided protrusively, with the maximum interval (S) between adjacent anti-slip ridges of 8 mm, in a width direction on the ground surface of the outer sole.SELECTED DRAWING: Figure 5

Description

The present invention relates to soles. More specifically, the present invention comprises at least two layers of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. In the sole, the hardness of the outer sole is set higher than the hardness of the midsole, and the anti-slip ridges having a shape and structure peculiar to the ground contact surface are formed to reduce the material cost and the manufacturing cost. Due to the synergistic effect of the difference in hardness between the outer sole and the midsole and the anti-slip ridges, durability, abrasion resistance, anti-slip (grip), and shock absorption, which are important performances for the sole, are achieved. Regarding soles with improved (cushioning) etc.

For current shoe development trends or merchandising, the gender, age, use, taste, materials used, price, fashion, etc. of the user are statistically analyzed in detail and used as development items, and each development item is combined. Tend to do it. For example, various athletics such as jogging and marathon, and various ball games such as tennis, soccer, and rugby are also performed in consideration of the maturity of beginners, intermediates, and advanced users in addition to the above-mentioned development items. There is also an example. As a result, traditional development or merchandising techniques have become a factor in raising material and manufacturing costs. On the other hand, from the consumer side, while suppressing various costs such as material cost and manufacturing cost, light weight, anti-slip property (grip property), durability, wear resistance, shock absorption (cushion property), safety, etc. There was also a request to give shoes the basic performance required, and this was also desired by the shoemaking industry from the perspective of shoe merchandising.

As one of the means, it has been proposed that the sole is a multi-layer structure composed of an outer sole and a mid sole. For example, there are soles made of ethylene-vinyl acetate copolymer (hereinafter abbreviated as "EVA") for the midsole and rubber for the outer sole. This conventional sole has the advantages of being durable, less likely to wear, and improving grip by using rubber for the outer sole, but has the disadvantages of high mass and high material cost that need to be improved. is there. In addition, there is a conventional technique in which all shoe soles are manufactured with an EVA-based composition containing a predetermined amount of rubber. This conventional technology has the advantage of reducing the material cost compared to the above-mentioned conventional soles in which the mid sole is made of EVA and the outer sole is made of rubber, but has the disadvantage of poor durability and easy wear. .. The hardness of the material can be increased to improve the durability, but on the other hand, there is a drawback that the cushioning property is lowered. In any case, the above-mentioned conventional shoe sole has advantages and disadvantages. Further, a sole in which an insert or shank having different physical properties is inserted in a part of the outer sole or the midsole has also been proposed.

The prior patent documents are described below.

Japanese Patent No. 3217024 Japanese Unexamined Patent Publication No. 2012-29762 Japanese Unexamined Patent Publication No. 2010-253128

In the illustrated Patent Document 1, a recessed portion D that is recessed in a concave shape is formed on a part of the peripheral side surface of the heel portion of the midsole 6, and a tongue piece-shaped core member 7 is inserted into the recessed portion D. Disclosed are injection-molded shoes 1, 1A, which have a three-layer structure and thereby exert an effect of shock absorption (cushioning property). Patent Document 1 does not describe or suggest the hardness of the outer sole 5 and the midsole 6, the shape and structure of the ground contact surface of the outer sole 5.

Patent Document 2 describes a shoe 1 in which a rigid member 6 having both rigidity and elasticity is arranged between a midsole 4 and an outer sole 5. Patent Document 2 describes the hardness of the rigid member 6 based on JISA, but does not describe or suggest the hardness of the midsole 4 and the outer sole 5, the hardness of each, and the shape and structure of the ground contact surface of the outer sole 5. ..

Patent Document 3 provides a flexible upper member 32 and a lower member 31 on the midsole 3, forms a gap 36 between the upper member 32 and the lower member 31, and provides a foot when touching the ground. Discloses footwear A that quickly absorbs and restores the impact on the footwear. However, Patent Document 3 does not describe or suggest the hardness of the outer sole 1 and the mid sole 3, the shape and structure of the ground contact surface of the outer sole 1.

The problems to be solved by the invention are as follows.

Therefore, the first problem to be solved by the present invention is a two-layer structure of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. In the sole made of, while suppressing the overall material cost and manufacturing cost, the durability, abrasion resistance and anti-slip property (grip property) of the outer sole are ensured, and the impact cushioning property of the midsole is improved. This is to reduce the mass of the entire sole.

The second problem to be solved by the present invention is a two-layer structure consisting of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. In the sole, the overall material cost and manufacturing cost are suppressed, the durability, wear resistance and anti-slip property (grip property) of the outer sole are ensured, and the shock absorption of the midsole is improved. It is to reduce the mass and improve the shape and structure of the ground contact surface of the outer sole to synergistically improve the anti-slip property.

Further problems to be solved by the invention will be clarified sequentially below.

In order to formulate a means for solving the above-mentioned problems, the present inventor, based on past empirical rules, joins the outer sole having a ground contact surface and the outer sole which is joined to the entire surface of the outer sole facing the ground contact surface. In the sole consisting of a two-layer structure with an integrated midsole, the technical matters described below were confirmed.
I. The outer sole contributes or is largely involved in the anti-slip property (grip property) and the wear resistance. The shock absorption (cushioning property) is mainly due to the midsole contributing or being involved.
B. Anti-slip (grip), wear resistance, and shock absorption (cushion) are due to their respective "hardness" as physical properties, and are greatly affected by "hardness".

Therefore, in consideration of past empirical rules, productivity, production cost, etc., the work of determining the upper and lower limits of the hardness range in which the outer sole satisfies both anti-slip (grip) and wear resistance is performed. went. As a specific procedure, in order to determine the hardness range of the outer sole that can be used, the outer sole has the original anti-slip property (grip property) and resistance, taking into consideration past empirical rules, productivity, production cost, etc. The central value for exhibiting abrasion resistance is set to 65 degrees (CT / Type), and outer soles with 21 types of hardness are placed on the left and right in the range of ± 10 degrees, that is, hardness of 75 degrees to 55 degrees. A total of 210 pairs of 10 pieces were manufactured according to the number of feet. On the other hand, in order to determine the hardness range of the available midsole, the midsole exerts its original shock absorption (cushioning property) in consideration of past empirical rules, productivity, production cost, etc. Set the hardness value to 50 degrees (CT / Type), and set 10 midsole with 21 kinds of hardness in the range of ± 10 degrees, that is, hardness 60 to 40 degrees, respectively, according to the left and right feet. , 210 pairs in total were manufactured.

Next, 21 types of outer soles having a hardness in the range of 75 to 55 degrees and 21 types of midsole having different hardness in the range of 60 to 40 degrees, which were manufactured as described above, were produced. 210 pairs of soles consisting of a two-layer structure consisting of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. Manufactured in minutes.

Then, using the soles manufactured as described above, sandal-type shoes with a simple structure for testing were manufactured, and 210 adult males with a foot size of 26 cm were actually used to make the mother. The group is divided into 1 month, 3 months, 6 months, and 12 months, and the degree of wear of the ground contact surface of the outer sole is mechanically measured, and the anti-slip property (grip property) and the shock absorption sensory test of the mid sole are tested. Was performed to perform statistical processing. As a result, it was determined that the upper limit value at which the outer sole exhibits the original anti-slip property (grip property) and wear resistance is 68 degrees and the lower limit value is 62 degrees. The upper limit value of 68 degrees and the lower limit value of 62 degrees are critical values, respectively. That is, if it is less than 62 degrees, it becomes easy to wear and cannot be used as an outer sole. On the contrary, if it exceeds the upper limit value of 68 degrees, it is too hard and there is no "bend" and it becomes "bend". This is because the resulting cushioning property is lost and the anti-slip performance is lowered. In addition, a sensory test of the shock absorption (cushioning property) of the midsole was performed by 210 monitors, and statistical processing was performed. As a result, the upper limit value at which the midsole exhibits the original shock absorption (cushioning property) was determined to be 53 degrees, and the lower limit value was determined to be 47 degrees. The upper limit value of 53 degrees and the lower limit value of 47 degrees are critical values, respectively. That is, if it is less than 47 degrees, it is not possible to achieve the physical property standard, and conversely, if it exceeds the upper limit value of 53 degrees, it is too hard and the shock absorption (cushioning property) is lowered, which makes it comfortable to wear. This is because it has an adverse effect.

By the way, the road surface includes not only non-slip road surfaces such as sandy ground and paved road surface with anti-slip treatment, but also slippery road surfaces such as frozen road surface, tiles, stones such as marble, and iron plates. In the case of such a road surface, it may be difficult to exert a sufficient anti-slip function only by setting the hardness of the contact patch of the outer sole to 62 degrees to 68 degrees (CType). In order to improve this point, the present inventor has studied the formation of a plurality of so-called anti-slip ridges having an anti-slip effect in the width direction of the ground contact surface of the outer sole. The anti-slip effect was sensibly evaluated by using the monitor by changing the shape and structure of the ridges in various ways. As a result, the anti-slip ridges having an average height (H) of 4 mm and a maximum width (W) of 4 mm in the vertical direction from the road surface to the lower bottom surface of the outer sole are the maximum of the adjacent anti-slip ridges. It was discovered that an effective anti-slip function is effective by forming a plurality of outer soles in the width direction of the ground contact surface with an interval (S) of 8 mm. In this case, the "width direction of the contact patch of the outer sole" is not the size of the shoe but the "watari width", and in the case of the outer sole of a shoe with a size of 26 cm, it depends on the counting method, but 30 Three to 32 pieces are formed. The "average depth (D) in the vertical direction from the road surface to the bottom surface of the shoe sole" can be rephrased as "the average height (H) from the lower bottom surface of the outer sole to the road surface". Here, the "lower bottom surface of the outer sole" means the surface of the outer sole closer to the road surface when the surface where the outer sole is joined to the mid sole is referred to as the "upper bottom surface of the outer sole". It is defined as "the lower sole of."

By the way, when the walking motion is roughly analyzed, it is a continuous motion of "backward kicking" and "landing". At the time of "backward kicking", the anti-slip ridges turn in the direction opposite to the traveling direction, and at the time of "landing", they return to their original positions. This movement of the anti-slip ridges that accompanies the walking movement is called "bending". The anti-slip function and cushioning effect of the outer sole are simultaneously exerted by the "bending" movement of the ridges that impart anti-slip properties with this special shape and structure. Therefore, the average depth (D) of the anti-slip ridges in the vertical direction from the road surface to the bottom of the sole (D) is 4 mm, the maximum width (W) is 4 mm, and the maximum distance (S) between adjacent ridges with anti-slip properties is 8 mm. Are each critical value, and if these values are not satisfied, the "bending" movement of the anti-slip ridge does not occur, and therefore the anti-slip function and cushioning effect of the outer sole are not effective.

Therefore, the above-mentioned problem can be solved by the means of any one of the following items.
1. 1. In a sole composed of at least two layers of an outer sole having a tread and a midsole that is joined to the entire surface of the outer sole facing the tread and integrated with the outer sole.
(A) The hardness (CType) of the outer sole is 62 to 68 degrees, the hardness (CTtype) of the midsole is 47 to 53 degrees, and (b) the road surface is directed toward the lower bottom surface of the outer sole. Anti-slip ridges with an average depth (D) of 4 mm and a maximum width (W) of 4 mm in the vertical direction are in contact with the outer sole, with the maximum distance (S) between adjacent ridges with anti-slip properties being 8 mm. Multiple protrusions in the width direction of the ground,
A sole composed of at least two layers of the outer sole and a midsole that is joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole.
2. 2. Further, in the means described in the above item 1, a continuous or discontinuous recessed portion is formed from the toe portion to the heel portion in the longitudinal direction of the ground contact surface of the outer sole.

As described in claim 1, the sole of the present invention has at least two of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. In the sole composed of layers
(A) The hardness (CType) of the outer sole is 62 to 68 degrees, the hardness (CType) of the midsole is 47 to 53 degrees, and (b) the road surface is directed toward the lower bottom surface of the outer sole. Anti-slip ridges with an average height (H) of 4 mm and a maximum width (W) of 4 mm in the vertical direction have a maximum distance (S) of 8 mm between adjacent anti-slip ridges, and the ground contact surface of the outer sole. Multiple protrusions in the width direction,
The sole is composed of at least two layers of the outer sole and the midsole which is joined to the entire surface of the outer sole facing the ground contact surface and is integrated with the outer sole, and is illustrated below. The effect is effective.

1. 1. In a shoe sole composed of a two-layer structure consisting of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole, the outer sole mainly contributes to the resistance. It has both wear resistance and anti-slip properties (grip properties), as well as shock absorption (cushion properties), which is largely contributed by the midsole, at the same time.

2. 2. Abrasion resistance and anti-slip properties (grip properties), which the outer sole greatly contributes, and shock absorption (cushion properties), which the mid sole greatly contributes, are also greatly contributed or involved in each "hardness". This was proved by the inventor's rule of thumb. In the present invention, the hardness (CType) of the outer sole is set to 62 to 68 degrees, and the hardness (CType) of the midsole is set to 47 to 53 degrees, respectively, so that the outer as a material has a large width. The choice of sole and midsole is expanded, and the range of combinations thereof is expanded. Therefore, various costs such as material cost and manufacturing cost can be reduced.

3. 3. Even if the same material is used for the outer sole and mid sole, it is only necessary to change the hardness of each, and it is not necessary to change each material, so the entire material including material management While controlling costs and manufacturing costs, ensure the durability, wear resistance and anti-slip (grip) of the outer sole, improve the impact cushioning of the midsole, and reduce the weight of the entire sole. That is.

4. By setting the hardness (CType) of the outer sole to 62 to 68 degrees and the hardness (CType) of the midsole to a specific range of 47 to 53 degrees, the durability and resistance of the outer sole due to changes in the physical properties of each hardness. The average height (H) in the vertical direction from the road surface to the lower bottom surface of the outer sole on the ground contact surface of the outer sole while ensuring wear resistance and anti-slip property (grip property) and improving the impact cushioning property of the mid sole. Anti-slip ridges with a maximum width (W) of 4 mm and adjacent ridges with anti-slip properties have a maximum distance (S) of 8 mm, and a plurality of anti-slip properties are provided in the width direction of the ground contact surface of the outer sole. By projecting the ridges, the durability, abrasion resistance and anti-slip property (grip property) of the outer sole due to the difference in hardness between the outer sole and the midsole are ensured, and the impact cushioning property of the midsole is improved. A synergistic effect with the anti-slip effect due to the ridges of the shape and structure of is effective.

The bottom view which shows one Embodiment of the shoe sole of this invention. The external view which looked at the embodiment of the sole of this invention from the front. FIG. 6 is an external view of an embodiment of the shoe sole of the present invention as viewed from the rear. The top view which shows one Embodiment of the shoe sole of this invention. A cross-sectional view on the left side of an embodiment of the sole of the present invention as viewed from the left side. A right sectional view of an embodiment of the shoe sole of the present invention as viewed from the right side. An enlarged cross-sectional view of the dotted line portion of FIG. The virtual line Aa drawn from the toe to the heel of the ground contact surface of the sole, the virtual line Bb drawn from the heel to the toe, and the intersection C of the virtual line Aa and the virtual line B-b. The figure described. FIG. 8 is a cross-sectional view taken along the virtual line ACB.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a bottom view of an embodiment of the shoe sole of the present invention. FIG. 2 is an external view of the embodiment shown in FIG. 1 as viewed from the front, and FIG. 3 is an external view of the embodiment shown in FIG. 1 as viewed from the rear. In FIGS. 1 to 3, 1 is an outsole, 2 is a midsole, 3 is an anti-slip ridge, and 4 is a recess.

Rubber or its equivalent used in the present invention General term "Rubber or its equivalent" is broadly defined as a material having rubber-like physical properties similar to natural rubber or synthetic rubber, in addition to natural rubber or synthetic rubber. Define.
The present invention relates to an outer sole having a ground contact surface and a sole consisting of at least two layers of a midsole that is joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. It is one of the most important constituent requirements of the invention to set the hardness of the above to be larger than the hardness of the midsole. Therefore, the main materials of the outer sole and the midsole are not particularly limited, and are appropriately selected from natural rubber, synthetic rubber, thermoplastic synthetic resin, thermoplastic elastomer, or a composition containing one or more of them, which will be described later. That is, the material of the outer sole and the midsole in the present invention can be selected from the materials conventionally used for the sole material in consideration of physical properties, processability, manufacturing cost, material cost and the like. More specifically, the materials of the outer sole and the midsole of the present invention are natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), styrene butadiene rubber (SBR), From natural or various synthetic rubbers exemplified by ethylene-propylene rubber (EPM) and the like, it can be arbitrarily selected in consideration of the physical properties, moldability, various costs and the like required for the sole. Alternatively, the material of the outer sole and the midsole of the present invention is a polystyrene-based thermoplastic elastomer (TPS), a polyolefin-based thermoplastic elastomer (TPO), a polyurethane-based thermoplastic elastomer (TPU), a polyester-based elastomer, a polyamide-based elastomer, or a poly. Various thermoplastic elastomers exemplified by vinyl chloride elastomers, ethylene-vinyl acetate copolymers (EVA) and the like can be arbitrarily selected in consideration of physical properties, moldability, various costs and the like required for shoe soles. In particular, ethylene-vinyl acetate copolymer (EVA), polyurethane-based thermoplastic elastomer (TPU), and polystyrene-based thermoplastic elastomer (TPS) have a rubber-like feel, low-temperature properties, adhesive properties, low specific gravity, high slip resistance, and abrasion resistance. It is excellent as a sole material for shoes, especially as an outer sole material, because it is excellent in physical properties such as, and can be molded by injection molding. However, since the specific gravity of ethylene-vinyl acetate copolymer (EVA), polyurethane-based thermoplastic elastomer (TPU), and polystyrene-based thermoplastic elastomer (TPS) is in the range of 0.89 to 1.26, it is determined as necessary. It is desirable to adjust to the specific gravity of.

The present inventor uses an ethylene-vinyl acetate copolymer (hereinafter, may be abbreviated as "EVA") as a shoe sole for a long period of time, and its material cost, processability including manufacturing cost, physical properties as a shoe sole, I have a wealth of data on characteristics, etc., so I will explain them. EVA is a random copolymer of ethylene and vinyl acetate [Vinyl Acetate (VAc)], and has a VAc content of 7 to 40 wt% or a composition range of 10 to 60 wt% according to the theory. Its physical properties vary greatly depending on the VAc content, and those with a VAc content of 7 wt% or less are close to the properties of polyethylene and are treated as its modified resin, while those with a VAc content of 20 wt% or more crystallinize. It loses its degree and exhibits its performance as an elastomer. When the VAc content is 43 wt% or more, the Tg is 20 ° C. or less, the tensile strength shows a minimum value, and the elongation shows a maximum value, that is, an elastomer having excellent flexibility and rubber elasticity. Therefore, in the present invention, the EVA used has a VAc content of 43 wt% or more, and the EVA used more preferably has a VAc content of 50 to 70 wt%.
In the present invention, EVA can be used by blending with other rubbers or equivalents thereof.

The polyurethane-based thermoplastic elastomer does not require a special vulcanization step, can be injection-molded, can be used as a recycled product during or after molding, and does not use a reinforcing agent such as carbon black. , It is a rubber material that has a high strength equal to or higher than that of reinforced vulcanized rubber, and therefore can be processed in the same manner as an isoplastic synthetic resin that can be colored and secondary processed. Polyurethane-based thermoplastic elastomers have a hydrogen bond restraint mode, polyurethane for the hard segment, polyester or polyether for the soft segment, specific gravity (ASTMD 297) of 1.13 to 1.26, mechanical strength and compression set. Excellent and capable of injection molding. Of course, the specific gravity can be set to a predetermined specific gravity suitable for the outer sole or the mid sole by a treatment such as foaming. Therefore, it can be preferably used as a material for the sole of the present invention.

Polystyrene-based thermoplastic elastomers do not require a special vulcanization step and can be injection molded, can be used as recycled products during or after molding, without the use of reinforcing agents such as carbon black. , It is a rubber material that has high strength equal to or higher than that of reinforced vulcanized rubber, and therefore can be processed in the same manner as isoplastic synthetic resin that can be colored and secondary processed. Polystyrene-based thermoplastic elastomers have a molecular structure in which polystyrene in the restraint (hard segment) and rubber-like molecules are bonded in the form of block copolymers, and the rubber-like molecules (soft segments) are diene polymers such as polybutadiene and polyisoprene. Alternatively, those saturated by hydrogenation are used. The specific gravity (ASTM D 297) of the polystyrene-based thermoplastic elastomer is 0.91 to 0.96; the tensile strength (JISK6301; unit kg / cm2) is 90 to 280; the tensile elongation (JISK6301; unit kg / cm) is 30 to 30 to 43; rebound resilience (JISK6301; unit%) is 48 to 55; compression set (JISK6301; 23 ° C. × 22h), unit%) is 49 to 64 ;. Therefore, it can be preferably used as a material for the sole of the present invention.

The rubber or an equivalent thereof used as the sole material of the present invention described above can be blended with various additives for rubber and thermoplastic synthetic resin in a predetermined amount, if necessary. Examples of various additives for rubber and thermoplastic synthetic resins include plasticizers, stabilizers, fillers, reinforcing materials, colorants, foaming agents, cross-linking agents (vulcanization agents and vulcanization accelerators) and the like. Among them, the foaming agent adjusts the specific gravity that contributes to the hardness of the outer sole and the midsole by foaming the rubber used as the sole material of the present invention or an equivalent thereof, so that the sole of the present invention is manufactured. It is a particularly important additive for shoes. Therefore, the following describes each of the foaming agents that are particularly suitable for use in the present invention.
Details 1: Inorganic foaming agent a. Ammonium carbonate This is particularly effective when the sole material of the present invention is natural rubber. The decomposition temperature is 30 to 60 ° C. to generate about 700 ml / g of carbon dioxide and ammonia. Therefore, the bubbles are open cells.
B. Sodium bicarbonate This is particularly effective when the sole material of the present invention is rubber. In the presence of moisture, the decomposition temperature is 60-150 ° C. to generate about 260 ml / g of carbon dioxide. Therefore, the bubbles are open cells.
Details 2: Organic foaming agent a. N, N'-dinitrosopentamethylenetetramine (abbreviated as DPT or DNPT)
Decomposition temperature: 190 ° C to 205 ° C (in air)
130 ° C to 190 ° C (in resin or using foaming aid)
Amount of gas generated: 260-270 ml / g
B. Azodicarbonamide (AC or ADC or ABFA abbreviation)
Decomposition temperature: 195 ° C to 200 ° C (in air)
160 ° C to 200 ° C (in resin)
Amount of gas generated: 250-300 ml / g
C. N, N'-dinitroso-N, N'-dimethylterephthalamide decomposition temperature: 105 ° C.
Amount of gas generated: 115 ml / g
D. Benzene Sulfonyl Hydrazide Decomposition Temperature: 90-95 ° C
Amount of gas generated: 130 ml / g
E. p-Toluenesulfonyl hydrazide decomposition temperature: 110 ° C
Amount of gas generated: 125 ml / g

When DPT or AC having a high decomposition temperature is used among the exemplified foaming agents, it is preferable to use a foaming aid to lower the decomposition temperature. A wide variety of products are on the market as foaming aids, and they can be appropriately selected.

An embodiment will be described with reference to the attached drawings.
[Shoe sole mold used]
The mold for the outer sole 1 was manufactured so that the size after molding the mold for the outer sole would be 26 cm. As shown in FIGS. 1, 2, 3, 6, 7, 8, and 9, the outer sole mold has a lower bottom surface of the outer sole 1 from the road surface after molding the outer sole 1. The average depth (D) in the vertical direction is 4 mm, the maximum width (W) is 4 mm, and the maximum distance (S) between the adjacent anti-slip ridges 3 is 8 mm. A plurality of protrusions are provided in the width direction of the ground contact surface of the outer sole 1, and a concave portion 4 continuous from the toe portion 6 to the heel portion 7 is formed in the longitudinal direction of the ground contact surface of the outer sole 1. Engraving was performed to manufacture a mold for the outer sole.
The mold for the midsole 2 was manufactured so that the size after molding was 26 cm. As shown in FIG. 4, the mold for the midsole 2 has protrusions formed so that 17 blind holes 5 are formed in the latter half of the midsole 2 after the molding of the midsole 2.

The composition of the EVA composition for outer sole used is shown in Table 1.
* 1) The hardness (CType) of the outer sole after molding is in the range of 62 to 68 degrees, that is, the specific gravity is in the range of 0.3 ± 0.03.

The composition of the EVA composition for midsole used is shown in Table 2.
* 2) The hardness (CType) of the midsole after molding is in the range of 47 to 53 degrees, that is, the specific gravity is within the range of 0.25 ± 0.03.

[Molding method]
The EVA composition for the outer sole shown in Table 1 and the EVA composition for the midsole shown in Table 2 are filled in the cavities of the outer sole mold and the midsole mold, respectively, and the surface pressure of the mold is filled. The foaming agent is thermally decomposed by primary heating at 168 ° C. × 6 minutes at 100 to 150 kg / cm2, then water-cooled in a press for 15 to 20 minutes, cooled to room temperature, and further, hot air at 100 to 110 ° C. After secondary heating for 20 minutes, the outer sole having a ground contact surface and the mid that is joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole, as shown in FIGS. 1 to 7. The sole composed of at least two layers of the sole was press-molded at the same time.

The physical property values of the outer sole and the midsole manufactured in Example 1 are measured and shown in Table 3.

As described in claim 1, the sole of the present invention has at least two of an outer sole having a ground contact surface and a midsole joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole. In the sole composed of layers
(A) The hardness (CType) of the outer sole is 62 to 68 degrees, and the hardness (CType) of the midsole is 47 to 53 degrees, and (b) the road surface is directed toward the lower bottom surface of the outer sole. Anti-slip ridges with an average height (H) of 4 mm and a maximum width (W) of 4 mm in the vertical direction have a maximum distance (S) of 8 mm between adjacent anti-slip ridges, and the ground contact surface of the outer sole. Multiple protrusions in the width direction,
Since the sole is composed of at least two layers of the outer sole and the midsole which is joined to the entire surface of the outer sole facing the ground contact surface and integrated with the outer sole, the outer as a material. Wider choice of sole and midsole, and combinations thereof, reduced material and manufacturing costs and other costs, consisting of at least two layers of midsole integrated with the outer sole Contributes to mass production of soles.

1 Outer sole 2 Midsole 3 Anti-slip ridge 4 Concave 5 Blind hole 6 Toe 7 Heel D Anti-slip ridge vertical average height (mm) toward the lower bottom surface of the outer sole
W Maximum width (mm) of anti-slip ridges
S Maximum distance between adjacent anti-slip ridges (mm)
A-a Virtual line drawn from the toe 6 of the ground contact surface of the sole to the heel 7 B-b Virtual line C drawn from the heel 7 of the ground contact surface of the sole to the toe 6 Virtual line A-a Intersection of virtual lines B-b

Claims (2)

It is composed of at least two layers of an outer sole (1) having a ground contact surface and a midsole (2) that is joined to the entire surface of the outer sole (1) facing the ground contact surface and integrated with the outer sole (1). In the sole
(A) The hardness (CType) of the outer sole (1) is 62 to 68 degrees, and the hardness (CTtype) of the midsole (2) is 47 to 53 degrees.
(B) Anti-slip ridges (3) having an average depth (D) of 4 mm and a maximum width (W) of 4 mm in the vertical direction from the road surface toward the lower bottom surface of the outer sole (1) are adjacent to each other. The maximum distance (S) between the anti-slip ridges (3) is 8 mm, and a plurality of protrusions are projected in the width direction of the ground contact surface of the outer sole (1).
At least two layers of the outer sole (1) and the midsole (2) which is joined to the entire surface of the outer sole (1) facing the ground contact surface and integrated with the outer sole (1). Sole made of. Further, it is characterized in that a continuous or discontinuous recessed portion (4) is bored from the toe portion (6) to the heel portion (7) in the longitudinal direction of the ground contact surface of the outer sole (1). The sole according to claim 1.