Plate, sole, shoe and plate manufacturing method

Abstract

To provide a plate capable of achieving both reduction in impact at the time of grounding and improvement in stability in a foot length direction, sole, shoes, and a manufacturing method of the plate.SOLUTION: A plate 300 is a plate used in a sole forming a part of a shoe, and includes a reinforcement part 310 made of a composite material including a synthetic resin and a plurality of fibers. The plurality of fibers in the reinforcement part 310 each have a weight mean fiber length of 0.4 mm or more and 7.0 mm or less and have orientation property in which orientations are aligned in a foot length direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to a plate, a sole, a shoe, and a method for manufacturing the plate. [Background technology]

[0002] In recent years, as the materials used to form the midsoles of soles have become lighter, an increasing number of soles have thicker midsoles to improve shock absorption. However, as a thicker sole increases the distance from the ground to the body's center of gravity, a plate is sometimes provided in the midsole to improve stability.

[0003] For example, JP 2018-534028 A discloses a sole structure including an outsole, a shock absorber provided on the outsole, a midsole provided on the shock absorber, and a footwear plate disposed between the shock absorber and the midsole. The footwear plate has uniform bending stiffness throughout its entire area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2018-534028 Summary of the Invention [Problem to be solved by the invention]

[0005] The footwear plate described in JP 2018-534028 A is made up of multiple fiber layers, which gives it extremely high bending rigidity, so that when running naturally, with the foot landing on the outside in the width direction, the load on the foot increases depending on how the foot strikes the ground. This becomes more pronounced the lower the plate is positioned on the sole.

[0006] An object of the present disclosure is to provide a plate, a sole, a shoe, and a method for manufacturing the plate that can simultaneously reduce impact when touching the ground and improve stability in the longitudinal direction of the foot. [Means for solving the problem]

[0007] A plate according to one aspect of this disclosure is a plate used in a sole that forms part of a shoe, and has a reinforcing portion made of a composite material containing a synthetic resin and a plurality of fibers, each of which has a weight average fiber length of 0.4 mm or more and 7.0 mm or less, and which has an orientation that is aligned in the length direction of the foot.

[0008] A plate according to another aspect of this disclosure is a plate used in a sole that constitutes part of a shoe, and has a reinforcing portion made of a composite material including a synthetic resin and a plurality of fibers, wherein the bending rigidity of the reinforcing portion in the foot length direction of the shoe is at least twice the bending rigidity of the reinforcing portion in the foot width direction of the shoe, and the plurality of fibers in the reinforcing portion each have a weight average fiber length of 0.4 mm or more and 7.0 mm or less.

[0009] A sole according to one aspect of the present disclosure includes the plate and a midsole that holds the plate.

[0010] A shoe according to one aspect of the present disclosure also includes the sole and an upper connected to the sole and positioned above the sole.

[0011] Furthermore, a plate manufacturing method according to one aspect of this disclosure is a method for manufacturing a plate used in a sole that constitutes part of a shoe, and includes a preparation step of preparing a mold having a space having a shape corresponding to the plate, and an injection step of injecting a composite material containing a synthetic resin and a plurality of fibers from the toe side toward the heel side of the mold, or from the heel side toward the toe side of the mold, to form a reinforcing portion having an orientation in which the orientation of the plurality of fibers is aligned in the length direction of the foot. [Effects of the Invention]

[0012] According to this disclosure, it is possible to provide a plate, a sole, a shoe, and a method for manufacturing the plate that can simultaneously reduce impact when touching the ground and improve stability in the length direction of the foot. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view schematically illustrating a shoe according to one embodiment of the present disclosure. [Figure 2] FIG. 1 is a plan view showing the relationship between the sole and the bones of the foot of a shoe wearer. [Figure 3] FIG. [Figure 4] FIG. 2 is a cross-sectional view schematically showing a mold used in manufacturing the plate. [Figure 5] FIG. 10 is a plan view showing a modified example of the plate. [Figure 6] FIG. 10 is a plan view showing a modified example of the plate. [Figure 7] FIG. 10 is a plan view showing a modified example of the plate. [Figure 8] FIG. 10 is a plan view showing a modified example of the plate. [Figure 9] FIG. 10 is a plan view showing a modified example of the plate. [Figure 10] FIG. 10 is a plan view showing a modified example of the plate. [Figure 11] 1 is a table showing the results of Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present disclosure will be described with reference to the drawings. Note that in the drawings referred to below, the same or equivalent components are assigned the same numbers. In the following description, terms such as foot length direction, foot width direction, forward, and rearward are used. These directional terms indicate directions as seen from the perspective of a wearer wearing shoe 1 placed on a flat surface P (see FIG. 1) such as the ground. For example, forward refers to the toe side, and rear refers to the heel side. Furthermore, medial refers to the medial side of the foot in the foot width direction (the side toward the first toe), and lateral refers to the lateral side of the foot in the foot width direction. Note that the foot width direction refers to the direction perpendicular to the foot length direction.

[0015] Fig. 1 is a cross-sectional view showing a shoe according to an embodiment of the present disclosure, Fig. 2 is a plan view showing the relationship between the sole and the bones of the foot of a shoe wearer, and Fig. 3 is a perspective view of a plate.

[0016] 2 shows the sole 10 including the plate 300 for the right foot, and FIG. 3 shows the plate 300 for the left foot. These plates 300 have bilaterally symmetrical shapes. This also applies to the sole 10 including the plate 300 and the shoe 1. The shoe 1 of this embodiment can be used as, for example, a sports shoe for running or the like, or a walking shoe, and the shoe 1 can be used for any purpose.

[0017] As shown in FIG. 1, the shoe 1 includes a sole 10 and an upper 20 .

[0018] The upper 20 is connected to the sole 10 and together with the sole 10 forms a space for accommodating the wearer's foot.

[0019] As shown in FIG. 1, the sole 10 includes an outer sole 100 , a midsole 200 , and a plate 300 .

[0020] The outer sole 100 constitutes the ground contact part and is made of resin, rubber, or the like.

[0021] The midsole 200 is provided on the outer sole 100. The midsole 200 is formed from a resin foam material or the like. The upper 20 is disposed on the midsole 200. In other words, the midsole 200 is provided between the upper 20 and the outer sole 100.

[0022] As shown in FIG. 1, the midsole 200 includes a lower midsole 210 and an upper midsole 220 .

[0023] The lower midsole 210 is provided on the outer sole 100. At least a portion of the lower surface of the lower midsole 210 is covered by the outer sole 100. Note that only a portion of the lower surface of the lower midsole 210 may be covered by the outer sole 100, or the entire area may be covered by the outer sole 100.

[0024] The upper midsole 220 is connected onto the lower midsole 210. The upper midsole 220 may have a stiffness higher than that of the lower midsole 210, or may have a stiffness equal to that of the lower midsole 210.

[0025] The plate 300 constitutes a part of the sole 10. The plate 300 is provided in the midsole 200. As shown in FIG. 1 , in this embodiment, the plate 300 is disposed within the midsole 200. Specifically, the plate 300 is disposed between the lower midsole 210 and the upper midsole 220. The plate 300 is bonded to at least one of the lower midsole 210 and the upper midsole 220. The midsole 200 has a housing portion that defines a space for housing the plate 300. The housing portion has a shape that corresponds to the shape of the plate 300.

[0026] As shown in Figures 1 and 2, the plate 300 has a shape that extends from a position where the front end of the wearer's foot of the shoe 1 overlaps with the thickness direction of the sole 10 to a position where the rear end of the wearer's foot overlaps with the thickness direction.

[0027] As shown in FIGS. 1 to 3, the plate 300 has a reinforcing portion 310. In this embodiment, the entire area of ​​the plate 300 is constituted by the reinforcing portion 310. However, the reinforcing portion 310 may be formed only on a part of the plate 300. The reinforcing portion 310 is made of a composite material containing a synthetic resin and a plurality of fibers. Examples of fibers contained in this composite material include carbon fiber, glass fiber, aramid fiber, Dyneema fiber, Zylon fiber, and boron fiber. In this embodiment, carbon fiber is used as the fiber. The reinforcing portion 310 is preferably formed by injection molding. The specific gravity of the reinforcing portion 310 is preferably 1.15 or less, and more preferably 1.13 or less. This specific gravity is preferably 1.05 or more.

[0028] The multiple fibers in the reinforced portion 310 each have a weight-average fiber length of 0.4 mm or more and are oriented in the leg length direction. These fibers more preferably have a weight-average fiber length of 0.4 mm or more and 7.0 mm or less. In this specification, "oriented" is defined as when the number of fibers per unit volume whose longitudinal direction forms an angle of 45 degrees or less with the leg length direction is 50% or more of the total number of fibers.

[0029] The foot length direction is a direction parallel to the shoe center SC (see FIG. 2). The shoe center SC is not limited to the center line of the shoe 1, but may be a line corresponding to a straight line connecting the center of the calcaneus and the space between the first and second toes of a typical wearer of the shoe 1.

[0030] The length of each fiber contained in the reinforcing portion 310 can be measured as follows: A sample piece, for example, 2 cm square, is taken from the reinforcing portion 310, and only the synthetic resin component contained in the sample piece is burned or dissolved to extract only a plurality of fibers, which are then measured using an optical microscope or the like. This measurement is preferably performed on, for example, about 400 to 1000 fibers.

[0031] The reinforcement part 310 has a higher orientation in the middle part (a region where the dimension in the foot width direction decreases toward the rear in the foot length direction) than in the front and rear ends in the foot length direction. The reinforcement part 310 has an orientation region 310R (see Figures 1 to 3) where the orientation gradually increases from the part located closest to the plane P when the shoe 1 is placed on the plane P toward the rear in the foot length direction.

[0032] The reinforcement portion 310 has a bending rigidity higher than that of the midsole 200. The bending rigidity of the reinforcement portion 310 in the foot length direction is at least twice the bending rigidity of the reinforcement portion 310 in the foot width direction. It is more preferable that the bending rigidity of the reinforcement portion 310 in the foot length direction is at least 2.5 times the bending rigidity of the reinforcement portion 310 in the foot width direction. For example, the bending rigidity of the reinforcement portion 310 in the foot length direction is set to be 10 GPa or more and 17 GPa or less. Furthermore, the bending rigidity of the reinforcement portion 310 in the foot width direction is set to be 5 GPa or more and 10 GPa or less.

[0033] The bending rigidity of the reinforcement portion 310 in the foot length direction refers to the rigidity when the reinforcement portion 310 is bent about a line parallel to the foot width direction. The bending rigidity of the reinforcement portion 310 in the foot length direction is measured by a three-point bending test. That is, a sample piece is cut out from the reinforcement portion 310, and the sample piece is supported at two points spaced apart in the foot length direction. The bending rigidity is measured by pressing the midpoint between the two points with a pusher in the thickness direction of the sample piece. For example, the sample piece is cut out to a size such that the distance between the support points is 24 mm and the dimension in the direction perpendicular to the direction connecting the support points is 10 mm. The pressing speed of the pusher is set to 2 mm / min.

[0034] The bending rigidity of the reinforcement part 310 in the foot width direction means the rigidity when the reinforcement part 310 is bent relative to a line parallel to the foot length direction. The method for measuring this bending rigidity is the same as the method for measuring the bending rigidity of the reinforcement part 310 in the foot length direction.

[0035] Next, a method for manufacturing the plate 300 will be described with reference to Fig. 4. This manufacturing method includes a preparation step and an injection step.

[0036] The preparation step is a step of preparing a mold 30 having a space 300S having a shape corresponding to the plate 300. The mold 30 has a lower mold 31 and an upper mold 32 that can be connected to and separated from the lower mold 31. The space 300S is formed at the boundary between the lower mold 31 and the upper mold 32. The mold 30 has a gate 33 that communicates with the space 300S. The gate 33 communicates with the toe-side end of the space 300S. However, the gate 33 may also communicate with the heel-side end of the space 300S.

[0037] The injection process is a process for forming a reinforcing part 310 having a plurality of fibers oriented in the foot length direction by injecting a composite material containing a synthetic resin and a plurality of fibers through the gate 33 from the toe side toward the heel side of the mold 30. When the gate 33 is connected to the heel side end of the space 300S, the composite material is injected from the heel side toward the toe side of the mold 30 in the injection process.

[0038] As described above, in the plate 300 of this embodiment, the fibers in the reinforced portion 310 have a weight-average fiber length of 0.4 mm or more and 7.0 mm or less, and are oriented uniformly in the foot length direction. Therefore, the bending rigidity of the reinforced portion 310 in the foot length direction is greater than the bending rigidity of the reinforced portion 310 in the foot width direction. Specifically, the bending rigidity of the reinforced portion 310 in the foot length direction is at least twice the bending rigidity of the reinforced portion 310 in the foot width direction. In other words, the bending rigidity of the reinforced portion 310 in the foot width direction is less than the bending rigidity of the reinforced portion 310 in the foot length direction. Therefore, in a natural running motion in which the foot strikes the ground from the outside in the foot width direction, the load on the foot when touching the ground is reduced. Furthermore, the high bending rigidity of the reinforced portion 310 in the foot length direction suppresses excessive deformation of the sole 10, especially during kick-off, thereby improving stability in the foot length direction.

[0039] Furthermore, since the plate 300 including the reinforcing portion 310 of this embodiment is formed by injection molding, excessive bending rigidity is avoided, as is the case with the footwear plate described in Patent Document 1 (JP 2018-534028 A), i.e., a structure in which multiple prepreg fiber sheets are stacked together.Furthermore, since each fiber in the reinforcing portion 310 has a uniform orientation in the lengthwise direction of the foot, the bending rigidity in the lengthwise direction of the foot required to provide running efficiency and stability is ensured.

[0040] Modifications of the above embodiment will now be described.

[0041] (First Modification) As shown in FIG. 5, the plate 300 may have a front reinforcement region R10 and a rear reinforcement region R20.

[0042] The front reinforcement region R10 extends from a front end 300a, which is located at the front end of the plate 300 in the foot length direction, to a rear end 300b, which is located at the rear end of the plate 300 in the foot length direction. More specifically, the front reinforcement region R10 extends from the front end 300a in the thickness direction of the sole 10 to a portion overlapping a line L10 connecting the centers of the metatarsals B10 of the wearer of the shoe 1. In the example shown in FIG. 5, the front reinforcement region R10 is formed in a range from the front end 300a of the plate 300 to a portion closer to the rear end 300b than line L10. In the example shown in FIG. 5, the front reinforcement region R10 is a region located in a range of approximately 0% to 60% of the total length of the plate 300 from the front end 300a toward the rear end 300b.

[0043] The front reinforcement region R10 has an inner foot region R11, an outer foot region R12, and a middle region R13.

[0044] The medial foot region R11 is formed on the medial side in the width direction of the foot, and is formed in a range that overlaps with the metatarsal bone B10 of the first toe in the thickness direction.

[0045] The outer foot region R12 is formed on the outer side in the width direction of the foot. The outer foot region R12 is formed in a range that overlaps with the metatarsal bone B10 of the fifth toe in the thickness direction.

[0046] The intermediate region R13 is formed between the medial foot region R11 and the lateral foot region R12. The intermediate region R13 is formed in a range overlapping with the metatarsal bone B10 of the second toe and the metatarsal bone B10 of the third toe in the thickness direction.

[0047] The rear reinforcing region R20 extends from the rear end of the front reinforcing region R10 to the rear end 300b of the plate 300.

[0048] The reinforcement portion 310 has a middle reinforcement portion 313 provided in the middle region R13 and a rear reinforcement portion 315 provided in the rear reinforcement region R20. The middle reinforcement portion 313 and the rear reinforcement portion 315 are continuous in the foot length direction. The rear reinforcement portion 315 is provided over the entire area in the foot width direction. In Figure 5, the middle reinforcement portion 313 and the rear reinforcement portion 315 are indicated by diagonal lines.

[0049] The plate 300 may further include an inner foot support portion 321 and an outer foot support portion 322 .

[0050] The inner foot support portion 321 is provided in the inner foot region R11. The bending rigidity of the inner foot support portion 321 in the foot width direction is smaller than the bending rigidity of the intermediate reinforcement portion 313 in the foot width direction.

[0051] The outer foot support portion 322 is provided in the outer foot region R12. The bending rigidity of the outer foot support portion 322 in the foot width direction is smaller than the bending rigidity of the intermediate reinforcement portion 313 in the foot width direction.

[0052] In this embodiment, the inner foot support portion 321 and the outer foot support portion 322 can be formed from a material different from that of the reinforcing portion 310, thereby increasing the degree of freedom in selecting the material for the inner foot support portion 321 and the outer foot support portion 322.

[0053] In the first modification, the inner foot region R11 in which the inner foot support portion 321 is provided may be formed of the reinforcement portion 310.

[0054] (Second Modification) As shown in Fig. 6, the reinforcement portion 310 may have an inner toe reinforcement portion 311 provided in the inner toe region R11 and an outer toe reinforcement portion 312 provided in the outer toe region R12. The shapes of the inner toe region R11 and the outer toe region R12 are the same as those of the first modification. In Fig. 6, the inner toe reinforcement portion 311 and the outer toe reinforcement portion 312 are indicated by diagonal lines.

[0055] The plate 300 may further include a middle support portion 323 provided in the middle region R13 and a rear support portion 325 provided in the rear reinforcement region R20. The middle support portion 323 and the rear support portion 325 are continuous in the foot length direction. The rear support portion 325 is provided over the entire area in the foot width direction.

[0056] The bending rigidity of the inner foot reinforcement 311 in the foot width direction is smaller than the bending rigidity of the intermediate support 323. The bending rigidity of the outer foot reinforcement 312 in the foot width direction is smaller than the bending rigidity of the intermediate support 323 in the foot width direction.

[0057] In the second modified example, the inner foot region R11 in which the inner foot reinforcement part 311 is provided may be made of the same material as the intermediate support part 323.

[0058] (Third Modification) As shown in Fig. 7, the plate 300 may have a front reinforcement region R10 and a rear reinforcement region R20. In this example, the front reinforcement region R10 is a region located in a range of approximately 0% to 65% of the overall length of the plate 300 from the front end 300a toward the rear end 300b. In the example shown in Fig. 7, the reinforcement parts 310 are provided over the entire front reinforcement region R10. Note that in Fig. 7, the reinforcement parts 310 are indicated by diagonal lines.

[0059] The plate 300 may further include a rear support portion 325 provided in the rear reinforcing region R20. The rear support portion 325 may have a bending rigidity lower than that of the reinforcing portion 310, or may have a bending rigidity higher than that of the reinforcing portion 310.

[0060] This plate 300 is formed by injecting a composite material containing synthetic resin and multiple fibers into the space 300S of the mold 30 from the toe side end, and injecting a material different from the composite material (such as a material consisting only of the synthetic resin) into the space 300S from the heel side end.

[0061] In this embodiment, the reinforcing portion 310 is arranged in a range that straddles the MP joint of the wearer's foot in the foot length direction, so that excessive deformation of the sole 10 is suppressed, particularly when pushing off.

[0062] (Fourth Modification) As shown in FIG. 8, the plate 300 may have a front reinforcement region R10 and a rear reinforcement region R20. The rear reinforcement region R20 extends from the rear end 300b of the plate 300 in the thickness direction of the sole 10 to a region overlapping a line L10 connecting the centers of the metatarsals B10 of the wearer of the shoe 1. In the example shown in FIG. 8, the rear reinforcement region R20 is formed in a range from the rear end 300b of the plate 300 to a region located closer to the front end 300a of the plate 300 than the line L10. In this example, the rear reinforcement region R20 is a region located in a range of approximately 0% to 70% of the total length of the plate 300 from the rear end 300b toward the front end 300a. Reinforcement portions 310 are provided throughout the entire rear reinforcement region R20. Note that the reinforcement portions 310 are indicated by diagonal lines in FIG. 8.

[0063] The plate 300 may further include a front support portion 330 provided in the front reinforcing region R10. The front support portion 330 may have a bending rigidity lower than that of the reinforcing portion 310, or may have a bending rigidity higher than that of the reinforcing portion 310.

[0064] This plate 300 is formed by injecting a composite material containing synthetic resin and multiple fibers into the space 300S of the mold 30 from the heel side end, and injecting a material different from the composite material (such as a material consisting only of the synthetic resin) into the space 300S from the toe side end.

[0065] In this embodiment, the reinforcing portion 310 is arranged in a range that straddles the Lisfranc joint of the wearer's foot in the foot length direction, thereby suppressing excessive deformation of the sole 10, particularly when pushing off.

[0066] (Fifth Modification) 9, the rear end portion 300b of the plate 300 may be formed at a position overlapping in the thickness direction with the third cuneiform bone (lateral cuneiform bone) B20 of the foot of the wearer of the shoe 1, or at a position slightly behind that position in the foot length direction. In this example, the entire area of ​​the plate 300 may also be formed by the reinforcing portion 310.

[0067] (Sixth Modification) As shown in FIG. 10, the rear end 300b of the plate 300 may be the same as that of the fifth modified example, and the edge on the front end side of the plate 300 may be composed of a front end edge 310a and a recessed edge 310b.

[0068] The front edge 310a is formed at a position overlapping the wearer's first and second distal phalanges in the thickness direction, or at a position forward of that position in the foot length direction. The front edge 310a has a shape that curves convexly forward in the foot length direction. More specifically, the front edge 310a has a shape that curves convexly forward along the shoe center SC.

[0069] The recessed edge 310b extends from the outer end of the front edge 310a in the foot width direction toward the outside in the width direction, toward the rear in the foot length direction, and has a shape that curves convexly toward the inside in the foot width direction. More specifically, the recessed edge 310b intersects with the wearer's heel center HC and has a shape that curves convexly toward the inside in the foot width direction. The heel center HC refers to the straight line connecting the center of the calcaneus and the space between the third and fourth toes of a typical wearer of the shoe 1. The radius of curvature of the recessed edge 310b is greater than the radius of curvature of the front edge 310a.

[0070] In this example, the entire area of ​​the plate 300 may be formed by the reinforcing portion 310. [Example]

[0071] Next, examples of the above embodiment will be described together with comparative examples.

[0072] (1) Weight average fiber length measurement A test piece cut from the molded product was placed in a solvent suitable for dissolving the synthetic resin. The test piece was then heated to separate the fibers from the synthetic resin. The solvent was then cast into filter paper, and the fibers dispersed in the dried filter paper were observed under an optical microscope (50-200x magnification) as described above. The fiber lengths of 1,000 randomly selected fibers were measured, and the weight-average fiber length (Lw) was calculated using the following formula: Average fiber length = Σ(Mi 2 ×Ni) / Σ(Mi×Ni) Mi: Fiber length (mm) Ni: Number of fibers with fiber length Mi

[0073] (2) Measurement of bending rigidity of molded products From the 80 mm × 80 mm × 2 mm thick rectangular plate specimens obtained in the examples and comparative examples, 80 mm × 10 mm × 2 mm thick strip specimens were cut out along the direction of resin flow during injection molding (hereinafter referred to as MD) and the direction perpendicular to the direction of resin flow during injection molding (hereinafter referred to as TD). The flexural rigidity of the cut strip specimens was measured using a three-point bending test jig (indenter radius 5 mm) with a support distance of 32 mm and a test speed of 2 mm / min. The test machine used was an "Instron" (registered trademark) universal testing machine, Model 5566 (manufactured by Instron Corporation).

[0074] (3) Measurement of specific gravity of molded products From the 80mm x 80mm x 2mm thick rectangular test pieces obtained in each Example and Comparative Example, 80mm x 10mm x 2mm thick strip test pieces were cut out. The specific gravity of the obtained 80mm x 10mm x 2mm thick test pieces was measured by the liquid immersion method. The solution used was distilled water, and the average value of five pieces was calculated.

[0075] (Example) TORAYCA® long fiber pellets "TLP9040" were injection molded using a Sumitomo Heavy Industries, Ltd. SE75DUZ-C250 injection molding machine under the following conditions: injection time: 2 seconds, back pressure: 10 MPa, dwell time: 10 seconds, cylinder temperature: 230°C, and mold temperature: 60°C to produce molded specimens measuring 80 mm x 80 mm x 2 mm. Here, cylinder temperature refers to the temperature of the part of the injection molding machine where the molding material is heated and melted, and mold temperature refers to the temperature of the mold into which the resin is injected to form the desired shape. The obtained specimens were left to stand in a constant temperature and humidity chamber adjusted to 23°C and 50% RH for 24 hours before undergoing property evaluation. The evaluation results obtained using the above methods are summarized in Table 1 shown in Figure 11.

[0076] (Comparative Example) TORAYCA® short fiber pellets "3101T-20V" were injection molded using a Sumitomo Heavy Industries, Ltd. SE75DUZ-C250 injection molding machine under the following conditions: injection time: 2 seconds, back pressure: 10 MPa, dwell time: 10 seconds, cylinder temperature: 270°C, and mold temperature: 60°C to produce molded specimens measuring 80 mm x 80 mm x 2 mm. Here, the cylinder temperature refers to the temperature of the part of the injection molding machine where the molding material is heated and melted, and the mold temperature refers to the temperature of the mold into which the molding material is injected to form the desired shape. The obtained specimens were left to stand in a constant temperature and humidity chamber adjusted to 23°C and 50% RH for 24 hours and then evaluated using the methods described above. The evaluation results are shown in Table 1, shown in Figure 11.

[0077] It should be noted that the embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims, not by the description of the embodiments and examples above, and further includes all modifications within the meaning and scope of the claims.

[0078] [Aspect] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0079] A plate according to one aspect of the above embodiment is a plate used in a sole that forms part of a shoe, and has a reinforcing portion made of a composite material containing a synthetic resin and a plurality of fibers, each of which has a weight average fiber length of 0.4 mm or more and 7.0 mm or less, and which has an orientation that is aligned in the length direction of the foot.

[0080] In this plate, each fiber in the reinforced portion has a weight-average fiber length of 0.4 mm or more and 7.0 mm or less, and is oriented uniformly in the foot length direction, so that the bending rigidity of the reinforced portion in the foot length direction is greater than the bending rigidity of the reinforced portion in the foot width direction. In other words, the bending rigidity of the reinforced portion in the foot width direction is less than the bending rigidity of the reinforced portion in the foot length direction. As a result, during a natural running motion in which the outside of the foot strikes the ground in the foot width direction, the load on the foot when touching down is reduced. Furthermore, because the bending rigidity of the reinforced portion in the foot length direction is high, excessive deformation of the sole, especially during push-off, is suppressed, improving stability in the foot length direction.

[0081] Furthermore, a plate according to another aspect of the above embodiment is a plate used in a sole that forms part of a shoe, and has a reinforcing portion made of a composite material containing a synthetic resin and a plurality of fibers, wherein the bending rigidity of the reinforcing portion in the foot length direction of the shoe is at least twice the bending rigidity of the reinforcing portion in the foot width direction of the shoe, and the plurality of fibers in the reinforcing portion each have a weight average fiber length of 0.4 mm or more and 7.0 mm or less.

[0082] This plate also provides the same effect as above.

[0083] It is also preferable that the specific gravity of the reinforcing portion is 1.15 or less, and the bending rigidity of the reinforcing portion in the foot length direction of the shoe is 10 GPa or more and 17 GPa or less.

[0084] The plate may have a front reinforcing region that extends from a front end portion that is located at the front end of the shoe in the foot length direction, in the thickness direction of the sole, to a portion that overlaps with a line connecting the centers of the metatarsals of the wearer of the shoe, and the reinforcing portion may be provided over the entire area of ​​the front reinforcing region.

[0085] In this embodiment, the reinforcing portion is arranged in a range that straddles the MP joint of the wearer's foot in the foot length direction, thereby suppressing excessive deformation of the sole, particularly when pushing off.

[0086] The plate may also have a rear reinforcing region that extends from a rear end portion located at the rear end of the shoe in the foot length direction, in the thickness direction of the sole, to a portion that overlaps with a line connecting the centers of the metatarsals of the wearer of the shoe, and the reinforcing portion may be provided over the entire rear reinforcing region.

[0087] In this embodiment, the reinforcing portion is positioned in the range spanning the Lisfranc joint of the wearer's foot in the foot length direction, thereby suppressing excessive deformation of the sole, particularly when pushing off.

[0088] The front reinforcement region may also have an inner foot region formed on the inside of the shoe in the foot width direction, an outer foot region formed on the outside of the shoe in the foot width direction, and an intermediate region formed between the inner foot region and the outer foot region.

[0089] In this case, the plate may further include an outer foot support portion provided in the outer foot region. The reinforcement portion may include an intermediate reinforcement portion provided in the intermediate region, and the bending stiffness of the outer foot support portion in the foot width direction may be smaller than the bending stiffness of the intermediate reinforcement portion in the foot width direction.

[0090] The plate may further include an inner foot support portion provided in the inner foot region. In this case, it is preferable that the bending stiffness of the inner foot support portion in the foot width direction is smaller than the bending stiffness of the intermediate reinforcement portion in the foot width direction.

[0091] The plate may further include a middle support portion provided in the middle region. The reinforcement portion may include an outer foot reinforcement portion provided in the outer foot region, and the bending stiffness of the outer foot reinforcement portion in the foot width direction may be smaller than the bending stiffness of the middle support portion in the foot width direction.

[0092] The reinforcement portion may further include an inner foot reinforcement portion provided in the inner foot region. In this case, it is preferable that the bending stiffness of the inner foot reinforcement portion in the foot width direction is smaller than the bending stiffness of the intermediate support portion in the foot width direction.

[0093] A sole according to one aspect of the above embodiment includes the plate and a midsole that holds the plate.

[0094] A shoe according to one aspect of the above embodiment includes the sole and an upper connected to the sole and positioned above the sole.

[0095] Furthermore, a plate manufacturing method according to one aspect of the above embodiment is a method for manufacturing a plate used in a sole that forms part of a shoe, and includes a preparation step of preparing a mold having a space having a shape corresponding to the plate, and an injection step of injecting a composite material containing a synthetic resin and a plurality of fibers from the toe side toward the heel side of the mold, or from the heel side toward the toe side of the mold, to form a reinforcing portion having an orientation in which the orientation of the plurality of fibers is aligned in the length direction of the foot.

[0096] In this plate manufacturing method, a reinforcing portion is formed in which multiple fibers are oriented in the longitudinal direction of the foot during the injection process, which means that a plate is manufactured that can simultaneously reduce impact when landing and improve stability in the longitudinal direction of the foot. [Explanation of symbols]

[0097] 1 shoe, 10 sole, 20 upper, 30 mold, 31 lower mold, 32 upper mold, 33 gate, 100 outer sole, 200 midsole, 210 lower midsole, 220 upper midsole, 300 plate, 300a front end, 300b rear end, 300S space, 310 reinforcement portion, 310a front edge portion, 310b concave edge portion, 310R orientation region, 311 inner foot reinforcement portion, 312 outer foot reinforcement portion, 313 intermediate reinforcement portion, 315 rear reinforcement portion, 321 inner foot support portion, 322 outer foot support portion, 323 intermediate support portion, 325 rear support portion, 330 front support portion, B10 metatarsal, B20 third cuneiform bone, HC heel center, R10 front reinforcement region, R11 Medial foot area, R12 lateral foot area, R13 mid-area, R20 posterior reinforcement area, SC shoe center.

Claims

1. A plate used in a sole that constitutes a part of a shoe, a reinforcing portion made of a composite material containing a synthetic resin and a plurality of fibers; The plurality of fibers in the reinforcing portion each have a weight average fiber length of 0.4 mm or more and 7.0 mm or less, and have an orientation in which the orientation is aligned in the foot length direction, a front reinforcing region extending from a front end portion located at the front end of the shoe in the foot length direction to a portion overlapping a line connecting the centers of the metatarsals of a wearer of the shoe in the thickness direction of the sole, The plate, wherein the reinforcing portion is provided over the entire front reinforcing region.

2. A plate used in a sole that constitutes a part of a shoe, a reinforcing portion made of a composite material containing a synthetic resin and a plurality of fibers; the bending rigidity of the reinforcement portion in the foot length direction of the shoe is at least twice the bending rigidity of the reinforcement portion in the foot width direction of the shoe, The plurality of fibers in the reinforcing portion each have a weight average fiber length of 0.4 mm or more and 7.0 mm or less, a front reinforcing region extending from a front end portion located at the front end of the shoe in the foot length direction to a portion overlapping a line connecting the centers of the metatarsals of a wearer of the shoe in the thickness direction of the sole, The plate, wherein the reinforcing portion is provided over the entire front reinforcing region.

3. The specific gravity of the reinforcing portion is 1.15 or less, The plate according to claim 1 or 2, wherein the reinforcing portion has a bending rigidity of 10 GPa or more and 17 GPa or less in the foot length direction of the shoe.

4. a rear reinforcing region extending from a rear end portion located at the rear end of the shoe in the foot length direction to a portion overlapping a line connecting the centers of the metatarsals of a wearer of the shoe in the thickness direction of the sole, The plate according to claim 1 , wherein the reinforcing portion is provided over the entire rear reinforcing region.

5. A plate according to any one of claims 1 to 4; a midsole that holds the plate.

6. A sole according to claim 5; an upper connected to the sole and positioned above the sole.

7. A method for manufacturing a plate used in a sole that constitutes a part of a shoe, a preparation step of preparing a mold having a space having a shape corresponding to the plate; an injection step of injecting a composite material containing a synthetic resin and a plurality of fibers from the toe side toward the heel side of the mold or from the heel side toward the toe side of the mold to form a reinforcing part having an orientation in which the orientation of the plurality of fibers is aligned in the foot length direction, the plate has a front reinforcing region that extends from a front end portion that is located at the front end of the shoe in the foot length direction to a portion that overlaps with a line connecting the centers of the metatarsals of a wearer of the shoe in the thickness direction of the sole, In the injection step, the composite material is injected into the mold so that the reinforcing portion is formed over the entire front reinforcing region.

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