Shoe outsole

Abstract

An outsole 1 comprises a high hardness portion 7 and a hardness portion 9. A hardness Ha of the high hardness portion 7 which is measured by a durometer of a type A is 75 to 100. A hardness Hb of the low hardness portion 9 which is measured by the durometer of the type A is equal to or more than and is less than 75. A value of (Ha/Hb) is 1.07 to 2.00. An area ratio of the high hardness portion 7 occupying a bottom e of the outsole 1 is 10% to 90%. An area ratio of the low dness portion 9 occupying the bottom face of the outsole 1 10% to 90%. The sum of the area ratio of the high hardness portion 7 and that of the low hardness portion 9 is 80% or more.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an outsole to be used for shoes such as tennis shoes, golf shoes, soccer shoes, jogging shoes or trekking shoes.

[0003] 2. Description of the Related Art

[0004] Important performance to be required for a shoe includes a difficult slip of a bottom and the ground, that is, an excellent gripping property. The shoe having an excellent gripping property prevents a wearer from falling down due to a slip. Moreover, the excellent gripping property also contributes to the easiness for the wearer to exercise. In order to enhance the gripping property, an outsole of the shoe has variously been devised.

[0005] For example, a protruded portion such as a stripe ridge or a projection is formed on a bottom face of an outsole for sneakers. The protruded portion is embedded in the ground so that the slip of the shoe and the ground can be suppressed. On the soft ground, particularly, the effect of preventing a slip due to the embedding action of the protruded portion can be obtained remarkably.

[0006] In order to enhance the gripping property, various investigations have been made in respect of blending. For example, Japanese Laid-Open Patent Publication No. 11-9302 (1999) has disclosed sports shoe comprising an inner layer and an outer layer which have different hardnesses from each other. Japanese Patent No. 2946215 has disclosed golf shoe in which the characteristic of a rubber composition forming a projection of a bottom face is varied depending on portions.

[0007] The protruded portion of the outsole should have a high rigidity such that it can be embedded in the ground. The protruded portion having a high rigidity can be achieved by selecting the kind of polymer to be used for the out sole or devising the amount of an additive to be blended with the polymer.

[0008] In the case in which the wearer kicks the ground, a portion closer to a heel in the outsole is kept away from the ground and a portion closer to a toe is grounded. More specifically, the out sole is brought in to a bending state. However, the outsole having a high rigidity to enhance the embedding property for the ground of the protruded portion lacks flexibility and is bent with difficulty because of the high rigidity. Accordingly, the shoe having the out sole gives a bad wear feeling to the wearer.

SUMMARY OF THE INVENTION

[0009] In consideration of such a problem, it is an object of the present invention to provide a shoe which is excellent in a griping property because a protruded portion thereof is easily embedded in the ground and is also excellent in a wear feeling because of a good bending property.

[0010] An outsole of the present invention comprises a high hardness portion and a low hardness portion. A hardness of the high hardness portion (which is measured by a durometer of a type A) is 75 to 100. A hardness of the low hardness portion is 50 to 75. An average hardness of the high hardness portion is 1.07 to 2.00 times as high as that of the low hardness portion. A protruded portion in the high hardness portion is easily embedded in the ground. Moreover, the outsole is easily bent by the low hardness portion. In the shoe comprising the out sole, accordingly, a gripping property and a wear feeling are compatible with each other. Preferably, the average hardness of the high hardness portion is 1.20 to 1.80 times as high as that of the low hardness portion.

[0011] Preferably, an area ratio of the high hardness portion occupying a bottom face is 10% to 90% and an area ratio of the low hardness portion occupying the bottom face is 10% to 90%. Consequently, the gripping property in the high hardness portion and the bending property in the low hardness portion can be well balanced.

[0012] It is preferable that the sum of the area ratio of the high hardness portion occupying the bottom face and that of the low hardness portion occupying the bottom face should be 80% or more. Consequently, the gripping property and the bending property are more compatible with each other.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a sectional view showing an outsole according to an embodiment of the present invention,

[0014] FIG. 2 is a bottom view showing the outsole illustrated in FIG. 1,

[0015] FIG. 3 is a typical enlarged sectional view showing the outsole illustrated in FIGS. 1 and 2,

[0016] FIG. 4 is a bottom view showing an outsole according to another embodiment of the present invention, and

[0017] FIG. 5 is a bottom view showing an outsole according to a further embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention will be described below in detail based on preferred embodiments with reference to the drawings.

[0019] FIG. 1 is a sectional view showing an outsole 1 according to an embodiment of the present invention. The outsole 1 comprises a stripe ridge 3 as a protruded portion on a bottom face. A stripe groove 5 is provided in portions other than the stripe ridge 3 in the bottom face. A projection may be formed as the protruded portion in place of the stripe ridge 3, and furthermore, the stripe ridge 3 and the projection may be formed together. A well known upper portion, an insole and the like are attached to the outsole 1 so that a shoe is constituted.

[0020] The outsole 1 is formed by crosslinking a rubber composition. A base rubber to be used for the rubber composition includes natural rubber, an isoprene rubber, a butadiene rubber, a styrene-butadiene rubber, a butyl rubber, an acrylonitrile-butadiene rubber, a chloroprene rubber, an ethylene-propylene-diene rubber, an acryl rubber, an epichlorohidrin rubber, a polysulfide rubber and an urethane rubber. These material rubbers may be used separately or two of them or more may be used together. A crosslinking agent, a filler, a softening agent, an antioxidant, a silanizing agent, a silane coupling agent, a vulcanization accelerator, a crosslinking assistant, a coloring agent or the like may be properly blended in the rubber composition. In place of the rubber, a synthetic resin or a thermoplastic elastomer may be used as the material polymer.

[0021] FIG. 2 is a bottom view showing the outsole 1 illustrated in FIG. 1. In FIG. 2, the stripe ridge 3 and the stripe groove 5 are not shown. The outsole 1 comprises a high hardness portion 7 and a low hardness portion 9. In FIG. 2, a portion shown in a half-tone dot is the high hardness portion 7 and the residual portion is the low hardness portion 9. As is apparent from FIG. 2, the high hardness portion 7 and the low hardness portion 9 are provided alternately from a toe toward a heel. The high hardness portion 7 is provided in seven places and the low hardness portion 9 is provided in sixth places. The high hardness portion 7 has a high rigidity. Therefore, the stripe ridge 3 formed in the high hardness portion 7 is deformed with difficulty by the wearer's weight, and can easily be embedded in the ground (soil, sand, lawn or the like). Since the low hardness portion 9 is flexible, it contributes to an enhancement in the bending property of the outsole 1.

[0022] The high hardness portion 7 has a hardness of 75 to 100. If the hardness of the high hardness portion 7 is less than 75, the embedding property of the stripe ridge 3 in the ground is deteriorated. If the hardness of the high hardness portion 7 is more than 100, the wearer has a push-up feeling on his (her) feet over a hard ground such as concrete. From these viewpoints, it is preferable that the high hardness portion 7 should have a hardness of 77 to 95, particularly, 78 to 90. A term of “hardness” to be used in this specification means a hardness measured by a durometer type A hardness meter in accordance with JIS-K6253.

[0023] All the high hardness portions 7 present in the seven places may be formed of the same rubber composition. In this case, the hardnesses of all the high hardness portions 7 are almost equal to each other. Moreover, a part of the high hardness portions 7 may be formed of a different rubber composition from that of the other high hardness portions 7 and both of them may have different hardnesses from each other.

[0024] The low hardness portion 9 has a hardness which is equal to or more than 50 and is less than 75. If the hardness of the low hardness portion 9 is less than 50, a stable wear feeling cannot be obtained. If the hardness of the low hardness portion 9 is 75 or more, the bending property of the outsole 1 becomes insufficient. From these viewpoints, it is preferable that the hardness of the low hardness portion 9 should be 55 to 73, particularly, 60 to 72.

[0025] All the low hardness portions 9 present in the six places may be formed of the same rubber composition. In this case, the hardnesses of all the low hardness portions 9 are almost equal to each other. Moreover, a part of the low hardness portions 9 may be formed of a different rubber composition from that of the other low hardness portions 9 and both of them may have different hardnesses from each other.

[0026] An average hardness of the high hardness portion 7 is 1.07 to 2.00 times as high as that of the low hardness portion 9. More specifically, when the average hardness of the high hardness portion 7 is represented by Ha and that of the low hardness portion 9 is represented by Hb, a value of (Ha/Hb) is 1.07 to 2.00. If the value of (Ha/Hb) is less than 1.07, the characteristics of the high hardness portion 7 and the low hardness portion 9 approximate to each other so that the gripping property and the bending property are incompatible with each other. If the value of (Ha/Hb) is more than 2.00, the wearer easily has a push-up feeling on his (her) feet. From these viewpoints, the value of (Ha/Hb) is preferably 1.12 to 2.00, more preferably, 1.20 to 1.80.

[0027] In the case in which the high hardness portion 7 is constituted by a first high hardness portion formed of a certain rubber composition and a second high hardness portion formed of another rubber composition, the average hardness Ha of the high hardness portion 7 is calculated by the following equation (I).

Ha=Ha1×Sa1/100+Ha2×Sa2/100  (I)

[0028] (In the equation (I), Ha1 represents a hardness of the first high hardness portion, Ha2 represents a hardness of the second high hardness portion, Sa1 represents an area ratio (%) of the first high hardness portion occupying all the high hardness portions, and Sa2 represents an area ratio (%) of the second high hardness portion occupying all the high hardness portions.)

[0029] More specifically, the average hardness Ha of the high hardness portion 7 is calculated based on a weighted means which takes the area ratio of the first high hardness portion to the second high hardness portion in to consideration. In the outsole 1 having three or more kinds of high hardness portions 7, the average hardness Ha of the high hardness portion 7 is calculated based on a weighted mean which takes the area ratio of each portion into consideration.

[0030] In the case in which the low hardness portion 9 is constituted by a first low hardness portion formed of a certain rubber composition and a second low hardness portion formed of another rubber composition, the average hardness Hb of the low hardness portion 9 is calculated by the following equation (II).

Hb=Hb1×Sb1/100+Hb2×Sb2/100  (II)

[0031] (In the equation (II), Hb1 represents a hardness of the first low hardness portion, Hb2 represents a hardness of the second low hardness portion, Sb1 represents an area ratio (%) of the first low hardness portion occupying all the low hardness portions, and Sb2 represents an area ratio (%) of the second low hardness portion occupying all the low hardness portions.)

[0032] More specifically, the average hardness Hb of the low hardness portion 9 is calculated based on a weighted mean which takes the area ratio of the first low hardness portion to the second low hardness portion into consideration. In the outsole 1 having three or more kinds of low hardness portions 9, the average hardness Hb of the low hardness portion 9 is calculated based on a weighted mean which takes the area ratio of each portion into consideration.

[0033] The area ratio of the high hardness portion 7 occupying the bottom face of the outsole 1 is preferably 10% to 90%, more preferably 20% to 80% and most preferably 25% to 70%. Moreover, the area ratio of the low hardness portion 9 occupying the bottom face of the outsole 1 is preferably 10% to 90%, more preferably 20% to 80% and most preferably 25% to 70%. If the area ratio of the high hardness portion 7 is less than the above-mentioned range or the area ratio of the low hardness portion 9 is more than the above-mentioned range, the gripping property of the shoe becomes insufficient and the wearer has a local push-up feeling in some cases. If the area ratio of the high hardness portion 7 is more than the above-mentioned range or the area ratio of the low hardness portion 9 is less than the above-mentioned range, the bending property of the shoe becomes insufficient and the shock absorbing performance of the outsole 1 becomes poor in some cases.

[0034] FIG. 3 is a typical enlarged sectional view showing the outsole 1 illustrated in FIGS. 1 and 2. In FIG. 3, the left side indicates the toe side of the shoe and the right side indicates the heel side thereof. In other words, a transverse direction in FIG. 3 indicates a longitudinal direction of the shoe. The area of the high hardness portion 7 means that of a figure in which the bottom face (exposed face) of the high hardness portion 7 is projected onto a ground surface (horizontal surface). Moreover, the area of the low hardness portion 9 means that of a figure in which the bottom face (exposed face) of the low hardness portion 9 is projected on to a ground surface (horizontal surface) In FIG. 3, for example, a double arrow A indicates a dimension in a longitudinal direction of the projected figure of the high hardness portion 7 and a double arrow B indicates a dimension in a longitudinal direction of the projected figure of the low hardness portion 9. Similarly, a dimension in a transverse direction of each of the high hardness portion 7 and the low hardnesses portion 9 (a dimension in a vertical direction on a paper in FIG. 3) is also measured. By using these projection dimensions, the area ratio of each portion is calculated.

[0035] The arrangement of the high hardness portion 7 and the low hardness portion 9 is not particularly restricted but it is preferable that both of them should be arranged alternately in the longitudinal direction as shown in FIG. 2. Consequently, even if a load is applied to any portion of the outsole 1, an excellent gripping property can be obtained. Furthermore, even if any portion of the outsole 1 is bent, an excellent bending property can be obtained. In the case in which the high hardness portion 7 and the low hardness portion 9 are arranged alternately in the longitudinal direction, it is preferable that the high hardness portion 7 and the low hardness portion 9 should be provided in two or more places, particularly, four or more places, respectively. Moreover, in the case in which the high hardness portion 7 and the low hardness portion 9 are arranged alternately in the longitudinal direction, it is preferable that the stripe ridge 3 should be formed over the whole bottom face of the outsole 1.

[0036] The following methods are employed for setting the hardness of the high hardness portion 7 to be higher than that of the low hardness portion 9.

[0037] (1) The amount of a filler (for example, silica, carbon black) in the rubber composition of the high hardness portion 7 is set to be larger than that in the rubber composition of the low hardness portion 9.

[0038] (2) The amount of a softening agent in the rubber composition of the high hardness portion 7 is set to be smaller than that in the rubber composition of the low hardness portion 9.

[0039] (3) In place of the rubber, a synthetic resin, a thermoplastic elastomer or the like is used as a material polymer for the high hardness portion 7.

[0040] FIG. 4 is a bottom view showing an outsole 11 according to another embodiment of the present invention. The outsole 11 also comprises a stripe ridge and a stripe groove over the whole bottom face thereof, which are not shown. The outsole 11 comprises a high hardness portion 13 and a low hardness portion 15. The outsole 11 also comprises an ultrahigh hardness portion 17. In FIG. 4, a portion shown in a half-tone dot indicates the high hardness portion 13, a black portion indicates the ultrahigh hardness portion 17, and a residual portion indicates the low hardness portion 15. As is apparent from FIG. 4, the outsole 11 has the area ratio of the high hardness portion 13 increased. The low hardness portion 15 also occupies a bottom face with an area ratio of 10% or more.

[0041] The hardness of the high hardness portion 13 is 75 to 100 in the same manner as the high hardness portion 7 of the outsole 1 shown in FIG. 2. Moreover, the hardness of the low hardness portion 15 is equal to or more than 50 and is less than 75 in the same manner as the low hardness portion 9 of the outsole 1 shown in FIG. 2. The hardness of the ultra high hardness portion 17 is more than 100. The average hardness of the high hardness portion 13 is 1.07 to 2.00 times as high as that of the low hardness portion 15.

[0042] In the outsole 11, a gripping property can be obtained by the high hardness portion 13 and a bending property can be obtainedbythe low hardness portion 15. Moreover, the ultrahigh hardness portion 17 can prevent the outsole 11 from being twisted or deformed so that the stability of the shoe can be enhanced.

[0043] In respect of more compatibility of the gripping property and the bending property, it is preferable that the sum of the area ratio of the high hardness portion 13 and that of the low hardness portion 15 should be 80% or more, particularly 90% or more. More specifically, it is preferable that the area ratio of a portion (that is, the ultrahigh hardness portion 17) other than the high hardness portion 13 and the low hardness portion 15 in the bottom face of the outsole 11 should be less than 20%, particularly, less than 10%.

[0044] FIG. 5 is a bottom view showing an outsole 19 according to a further embodiment of the present invention. The outsole 19 also comprises a stripe ridge and a stripe groove over the whole bottom face thereof, which are not shown. The outsole 19 comprises a high hardness portion 21 and a low hardness portion 23. Moreover, the outsole 19 also comprises an ultrahigh hardness portion 25. In FIG. 5, a portion shown in a half-tone dot indicates the high hardness portion 21, a black portion indicates the ultrahigh hardness portion 25, and a residual portion indicates the low hardness portion 23. As is apparent from FIG. 5, the outsole 19 has the area ratio of the low hardness portion 23 increased. The high hardness portion 21 also occupies a bottom face with an area ratio of 10% or more.

[0045] The hardness of the high hardness portion 21 is 75 to 100 in the same manner as the high hardness portion 7 of the outsole 1 shown in FIG. 2. Moreover, the hardness of the low hardness portion 23 is equal to or more than 50 and less than 75 in the same manner as the low hardness portion 9 of the outsole 1 shown in FIG. 2. The hardness of the ultrahigh hardness portion 25 is more than 100. The average hardness of the high hardness portion 21 is 1.07 to 2.00 times as high as the average hardness of the low hardness portion 23.

[0046] Also in the outsole 19, a gripping property can be obtained by the high hardness portion 21 and a bending property can be obtained by the low hardness portion 23. Moreover, the ultrahigh hardness portion 25 can prevent the outsole 11 from being twisted or deformed so that the stability of the shoe can be enhanced.

[0047] In respect of more compatibility of the gripping property and the bending property, it is preferable that the sum of the area ratio of the high hardness portion 21 and that of the low hardness portion 23 should be 80% or more, particularly 90% or more. More specifically, it is preferable that the area ratio of a portion (that is, the ultrahigh hardness portion 25) other than the high hardness portion 21 and the low hardness portion 23 in the bottom face of the outsole 19 should be less than 20%, particularly, less than 10%.

EXAMPLES

Example 1

[0048] 80.0 parts by weight of isoprene rubber (trade name of “Nipol IR-2200L” manufactured by Nippon Zeon Co., Ltd.), 20.0 parts by weight of butadiene rubber (trade name of “BR18” manufactured by Japan Synthetic Rubber Co., Ltd.), 70 parts by weight of silica (trade name of “Ultrasil VN3” manufactured by Degusa Co., Ltd.), 6.0 parts by weight of silane coupling agent (trade name of 37 Si6938 manufactured by Degusa Co., Ltd.), 2.0 parts by weight of process oil (trade name of “PW380” manufactured by Idemitsu Kosan Co., Ltd.), 0.5 part by weight of antioxidant (trade name of “Sunnoc N” manufactured by Ouchi Shinko Kagaku Kogyou Co., Ltd.), 2.0 parts by weight of 2, 6-di-tert-butyl-4-methylphenol (trade name of “Nocrac 200” manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.), 3.0 parts by weight of zinc oxide, 1.0 part by weight of stearic acid, 1.5 parts by weight of sulfur, 1.0 part by weight of N-tert-butyl-2-benzothiazolylsulfenamide (trade name of “Nocceler NS” manufactured by Ouchi Shinko Kagaku Kogyou Co., Ltd.) as a vulcanization accelerator, 0.3 part by weight of zinc diethyldithiocarbamate (trade name of “Nocceler EZ” manufactured by Ouchi Shinko Kagaku Kogyou Co., Ltd.) as another vulcanization accelerator, and 0.5 part by weight of di-o-tolylguanidine (trade name of “Nocceler DT” manufactured byOuchi ShinkoKagakuKogyouCo., Ltd.) as another vulcanization accelerator were kneaded by means of an internal mixer. Thus, a rubber composition for a high hardness portion was obtained. Moreover, a rubber composition for a low hardness portion was obtained in the same manner as the rubber composition for the high hardness portion except that the amount of silica is 50 parts by weight.

[0049] On the other hand, a mold comprising an outsole-shaped cavity was prepared, and the rubber composition for the high hardness portion and the rubber composition for the low hardness portion were arranged alternately in the cavity as shown in FIG. 2. Then, pressurization and heating were carried out for 8 minutes at a temperature of 160° C. so that an outsole was obtained. An upper portion and an insole were attached to the outsole. Thus, the shoe according to the first embodiment was obtained. The outsole of the shoe has a sectional shape shown in FIG. 1. A hardness Ha of the high hardness portion, a hardness Hb of the low hardness portion, (Ha/Hb), an area ratio of the high hardness portion and an area ratio of the low hardness portion in the shoe are shown in the following Table 1.

Examples 2 to 6 and Comparative Examples 1 to 3

[0050] Shoes according to examples 2 to 6 and comparative examples 1 to 3 were obtained in the same manner as in the example 1 except that the amount of silica was varied and the hardness Ha of the high hardnesss portion and the hardness Hb of the low hardness portion were changed as shown in the following Tables 1 and 2.

Example 7

[0051] A shoe according to the example 7 was obtained in the same manner as in the example 1 except that a high hardness portion had a small width and was provided in five places and a low hardness portion had a great width and was provided in six places, and the high hardness portion had an area ratio of 20% and the low hardness portion had an area ratio of 80%.

Example 8

[0052] A shoe according to the example 8 was obtained in the same manner as in the example 1 except that a high hardness portion had a great width and was provided in six places and a low hardness portion had a small width and was provided in five places, and the high hardness portion had an area ratio of 80% and the low hardness portion had an area ratio of 20%.

Example 9

[0053] A shoe according to the example 9 was obtained in the same manner as in the example 1 except that an outsole had an ultrahigh hardness portion as shown in FIG. 4. A hardness of the ultrahigh hardness portion is achieved by an increase in the amount of silica. A hardness and an area ratio in each portion are shown in the following Tables 1 and 2.

Example 10

[0054] A shoe according to the example 10 was obtained in the same manner as in the example 1 except that an outsole had an ultrahigh hardness portion as shown in FIG. 5. A hardness of the ultrahigh hardness portion is achieved by an increase in the amount of silica. A hardness and an area ratio in each portion are shown in the following Tables 1 and 2.

[0055] [Evaluation of Function]

[0056] Five testers wore the shoes according to each example and each comparative example, and a gripping property, a bending property, a stability and a push-up feeling were evaluated in five stages of “1” to “5”. In the evaluation of the gripping property, a difficult slip in walking on a lawn was evaluated as “5” and an easy slip in the walking on the lawn was evaluated as “1”. Referring to the bending property, easy bending in a kick on the ground was evaluated as “5” and difficult bending was evaluated as “1”. In respect of the stability, stable walking on concrete was evaluated as “5” and unstable walking on the concrete was evaluated as “1”. In respect of the push-upfeeding, a small push-up feeling for the walking on the concrete was evaluated as “5” and a great push-up feeling was evaluated as “1”. These results are shown in the following Tables 1 and 2. 1 TABLE 1 Com. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 7 Ex. 1 Ex. 8 Type of bottom face Hardness Ha 72 75 79 79 80 80 80 Hardness Hb 70 50 65 73 71 71 71 Ha/Hb 1.03 1.50 1.21 1.08 1.13 1.13 1.13 Area ratio (%) of high 50 50 50 50 20 50 80 hardness portion Area ratio (%) of low 50 50 50 50 80 50 20 hardness portion Gripping property 3.5 4.1 4.7 4.3 4.6 4.6 4.9 Bending property 5.0 4.8 4.8 4.5 4.9 4.6 4.2 Push-up feeling 4.8 4.8 4.6 4.7 4.8 4.5 4.8 Stability 4.5 4.0 4.8 4.8 4.6 4.7 4.9

[0057] 2 TABLE 2 Com. Com. Ex. 5 Ex. 6 Ex. 2 Ex. 3 Ex. 9 Ex. 10 Type of bottom face Hardness Ha 88 96 96 102 80 80 Hardness Hb 45 54 96 48 71 71 Hardness of ultrahigh — — — — 102 102 hardness portion Ha/Hb 1.96 1.78 1.00 2.13 1.13 1.13 Area ratio (%) of high 50 50 50 50 86 12 hardness portion Area ratio (%) of low 50 50 50 50 12 86 hardness portion Area ratio (%) of ultra- — — — — 2 2 high hardness portion Gripping property 4.8 4.8 4.8 4.9 4.7 4.4 Bending property 4.2 4.3 1.8 4.2 4.2 4.8 Push-up feeling 4.0 4.2 4.1 1.8 4.2 4.8 Stability 4.5 4.2 4.6 1.9 4.3 4.6

[0058] In the Tables 1 and 2, the shoe according to each comparative example has a value of less than 4.0 for any of evaluation item. On the other hand, the shoe according to each example has a value of 4.0 or more for all the evaluation items. Consequently, it is apparent that the present invention has advantages.

[0059] The above description is only illustrative and can be variously changed without departing from the scope of the invention.

Claims

1. An outsole comprising a high hardness portion in which a hardness measured by a durometer of a type A is 75 to 100 and a low hardness portion in which a hardness measured by the durometer of the type A is equal to or more than 50 and is less than 75, an average hardness of the high hardness portion being 1.07 to 2.00 times as high as that of the low hardness portion.

2. The outsole according to claim 1, wherein the average hardness of the high hardness portion is 1.20 to 1.80 times as high as that of the low hardness portion.

3. The outsole according to claim 1, wherein an area ratio of the high hardness portion occupying a bottom face is 10% to 90% and an area ratio of the low hardness portion occupying the bottom face is 10% to 90%.

4. The outsole according to claim 1, wherein a sum of the area ratio of the high hardness portion occupying the bottom face and that of the low hardness portion occupying the bottom face is 80% or more.

5. The outsole according to claim 1, wherein a protruded portion is present on the bottom face of the high hardness portion.

6. The outsole according to claim 1, wherein the high hardness portion and the low hardness portion are arranged alternately in a longitudinal direction.

7. The out sole according to claim 1, where in the high hardness portion is provided in two places or more and the low hardness portion is provided in two places or more.

8. A shoe having an out sole comprising a high hardness portion in which a hardness measured by a durometer of a type A is 75 to 100 and a low hardness portion in which a hardness measured by the durometer of the type A is equal to or more than 50 and is less than 75, an average hardness of the high hardness portion being 1.07 to 2.00 times as high as that of the low hardness portion.