JPS61154503A - Mid-sole - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

The present invention relates to a midsole that can enhance running functionality and improve moldability. In recent years, the soles of footwear have changed to sponge soles in order to reduce the impact on the feet when driving on stone roads, concrete paved roads, etc., and thicker sponge soles are now being worn depending on the function. In such soles, the outsole is usually solid or a sponge sole with good abrasion resistance, and one or a suitable number of sponge layers with good cushioning properties are inserted between the outsole and the cover. This layer is called midsole. This mid-sole requires a certain degree of hardness, is quite thick, and requires bending force that can resist the repulsive force of the cushion layer itself at the stepping part, which puts extra load on the wearer's feet. I felt fatigued and lost the feeling of wearing them. In addition, the midsole is made up of layers of different colors,
In particular, when a sponge layer with low hardness and good cushioning properties is layered to reduce weight, the outer wall surface of that layer is exposed, resulting in large compressive strain and, in addition, fatigue. The cushioning properties significantly decreased over a short period of time, impairing the feeling of wearing the shoes, and the poor shape retention promoted lateral vibration, deteriorating the running functionality. In view of the current situation, the present invention combines a polyester urethane outer layer foam and a resilient inner layer foam to improve the excellent breaking strength and compression properties of the polyester urethane outer layer foam. By effectively utilizing the advantages of low permanent deformation and good recovery power, as well as the cushioning properties and lightness of the resilient inner layer foam,
The object of the present invention is to provide a midsole with excellent shape retention and moldability, and excellent running functionality. The present invention comprises at least two polymeric foam layers layered between the outsole and the sleeve, the polymeric foam layers having a contour that roughly follows the outsole, and an elastic inner layer made of foam. The body is covered with an outer foam made of polyester-based urethane. The midsole of the present invention uses a combination of materials having different hardnesses for the polyester urethane outer layer foam and the elastic inner layer foam, as described above.
A smooth hardness difference is created between each part. The hardness of the outer layer foam is in the range of 25 to 80 degrees as measured by Asker hardness tester C type (the same applies hereafter), the hardness of the inner layer foam is in the range of 20 to 60 degrees, and the average specific gravity of the inner layer foam is O. ,OS~
0.30, average specific gravity of outer layer foam is 0.20~0°60
range is used. Weight reduction can be achieved by selecting and combining members from this range to reduce the hardness of appropriate parts such as the stepping part and the central part. This midsole is layered between the outsole and the toe cover, and its lower surface is formed to follow the contour of the upper surface of the outsole, and the upper surface is formed to follow the lower surface contour of the toe cover. Examples of the inner layer foam include foams of polyolefin resins such as polyethylene, ethylene-vinyl acetate copolymer (EVA), rubber, and mixtures thereof. The polyester urethane foam of the outer layer foam is made of 4,4-diphenylmethane diisocyanate, 4
．． Diisocyanates such as 4°-dicyclohexylmethadiisocyanate, ethylene glycol, glycols such as 1,4-hexanediol, adipate-based polyethylene adipate, poly(1,4-butylene adipate),
This is a urethane foam obtained by reacting polyester diol such as poly(1,6-hexanediol). Examples of the present invention will be explained below with reference to the drawings. Fig. 1 shows the midsole of the first example, (a) is a plan view, (bl is a longitudinal cross-sectional view thereof, Fig. 4 is a modified version of Fig. 1, (g) is a plan view, (h) is a longitudinal cross-sectional view thereof, and Fig. 5 is a similar view. This is a modified version of Figure 1, (jl is a plan view, (
kl is a longitudinal cross-sectional view. The inner foam layer (1) of the midsole shown in FIG. 1 has a shape that is almost similar to the outline of the outsole, and is formed to have a thinner thickness at the front and a thicker thickness at the rear. The entire surface of the inner foam layer (1) is covered with the outer foam layer (2) to obtain a midsole with an optimal shape. The inner layer foam in this case (
1) is foamed E with a hardness of 30 degrees and an average specific gravity of 0.07 to 0.1.
The outer layer foam (2) is VA and has a hardness of 50 degrees and an average specific gravity of 0.3.
~0.4 polyester foam polyurethane is used. The inner layer foam (1) is made by cutting foamed EVA plates and combining and joining them to increase the thickness of the rear part, or as shown in Fig. 4, two pieces of foamed EVA temporary are placed on the tip part (5) and the heel part side. It may be divided, and then the heel side thereof may be cut into two layers, an upper layer (6) and a lower layer (7), and then combined and joined. In this case, of course, the hardness of each part is appropriately combined. The hardness is, for example, 20 degrees at the tip (5), 35 degrees at the upper layer (6) of the heel, and 45 degrees at the lower layer (7). In addition, as shown in FIG. 5, the structure of the heel includes a horseshoe-shaped part (8) on the outside made of the hardest material at the tip (9) of the heel, and the inner push side of this horseshoe-shaped part. By configuring the ankle to be pulled out to a position closer to the toe side than the external push side, when the pressure at the time of landing moves from the external push side to the internal push side, the pressure applied to the internal push side causes the ankle part to rotate toward the internal push side. Various design changes are possible, such as to avoid damage to ankles and the like due to excessive wear. The structure of these inner layer foams (1) can also be applied to the following second and third embodiments. Alternatively, it can be obtained by cutting an unfoamed EVA composition into a predetermined shape, pressing and heating it in a mold, and simultaneously molding it into one piece at the same time as foaming. This inner layer foam (1) is layered approximately in the center of the recess corresponding to the midsole formed by combining the upper mold and the lower mold by appropriate means, and the liquid which becomes the outer layer foam (2) is deposited in this recess. The polyurethane material is injected and subjected to a foaming and curing reaction to form a midsole made of a polymeric foam in which the inner layer foam (1) is tightly covered with the outer layer foam 'C2). By changing the contour of the inner foam layer (1) as necessary, the contour width of the outer layer foam (2) can be freely changed along this contour. Figure 2 is a second embodiment of the present invention, (C) is a plan view, (d)
is a longitudinal sectional view thereof. In this example, as shown in FIG. 2, the inner layer foam (1) has a hardness of 35 degrees and an average specific gravity of 0.1 to 0.
．． 15 (7) foamed EVA, outer layer foam (2) has a hardness of 5
Polyester-based foamed polyurethane with a temperature of 0 degrees and an average specific gravity of 0.3 to 0.4 is used, and almost the entire surface of the inner layer foam (1) is covered with the outer layer foam (2), as in the first embodiment. The outer foam layer (2) on the upper surface of the front part is removed around the tread area, and the inner layer foam (1) is formed to directly protrude to the surface so as to fill this removed area. . Only the front upper surface of the inner layer foam (1) is held so as to be in contact with the inner surface of the upper mold, and liquid polyurethane material that will become the outer layer foam (2) is injected into the recess formed by combining the upper mold and the lower mold. Then, a foaming and curing reaction is carried out to form a midsole which is a polymeric foam. FIG. 3 shows a third embodiment of the present invention, in which (e) is a plan view and (f) is a longitudinal sectional view thereof. In this embodiment, as shown in FIG. 3, the inner layer foam (1) is made of foamed EVA with a hardness of 35 degrees and an average specific gravity of 0.1 to 0.15, and the outer layer foam (2) is foamed EVA with a hardness of 55 degrees and an average specific gravity of 0.15. Polyester foam urethane having a diameter of 4 to 0.5 is used, and the inner foam layer (1) is covered with the outer foam layer (2) in substantially the same manner as in the first embodiment. In this example, both sides of the treading part of the inner layer foam (1),
A suitable number of protrusions (3) are provided on the outer heel side of the heel, and the outer push side end faces of these protrusions (3) are formed to match the contour end face of the outer layer foam (2). In addition, a concave curved portion (4) is provided from the inner side of the heel of the inner layer foam (1) toward the center of the arch, and the contour width of the outer layer foam (2) is adjusted to match this curved portion (4). be larger than other contour widths. An appropriate number of protrusions (3) provided on both sides of the stepping part of the inner layer foam (1) and on the outer side of the heel are further extended,
The extended portion of the protrusion (3) is fitted into a holding hole that communicates with the recess formed by the upper and lower molds, and the liquid polyurethane material that will become the outer layer foam (2) is injected. After removing the mold, the extended portion of the protrusion (3) is cut out along one end surface of the contour, and the end surface of the protrusion (3) of the inner layer foam (1) is raised to a height that appears on the contour end surface. Forms a midsole made of molecular foam layer. In this embodiment as well, the front upper surface including the protrusion (3) around the stepping part and the heel protrusion (3)
The outer foam layer (2) on the top surface may be removed, and the inner foam layer (1) may be formed directly on the surface so that the inner layer foam (1) fills this removed portion. The color tone of this protrusion (3) is
The color tone of the inner layer foam (1) may be matched, or the protrusions (
3) Or only the outer edge is red. Color it blue, yellow, etc. Further, the shape of the outer end surface of the protrusion (3) is formed into an appropriate shape such as a circle, a triangle, or a rhombus depending on its function. As described above, in the midsole of Example 1, the entire surface of the inner layer foam (1) made of foamed EVA that is similar to the bottom shape is covered and bonded with the outer layer foam (2) made of polyester foam polyurethane. The disadvantages of foamed EVA are that it has no breaking strength and can be damaged by a slight external force, and polyester-based foamed polyurethane, especially low-foamed polyurethane, has the disadvantage of not being lightweight and causing sink marks in thick parts such as the heel. This effectively brings out the advantages of foamed EVA's cushioning properties and light weight, as well as the high breaking strength, low compression set, and good recovery power of polyester foam polyurethane. I was able to do that. By reducing the thickness of the stepped portion of the outer foam layer (2), flexibility can be increased and bending resistance to the foot of the wearer can be alleviated. In addition, even if the heel part of the inner foam layer (1) is thicker, it is still covered and bonded with the outer foam layer (2), which has a higher hardness than the inner foam layer (1), so it is lightweight and has plenty of cushioning properties. It has a structure in which the thick heel part of the inner foam (1) is enclosed in the heel part and is covered by a thin layer of the outer foam (2). Therefore, it is lightweight without causing sink marks, and has the effect of cushioning and absorbing the impact when landing. Furthermore, since the inner layer foam (1) is covered with the outer layer foam (2) which has a higher hardness, the hardness on this upper surface decreases from the contour to the center, and the hardness changes smoothly. However, the wearer does not experience discomfort such as unevenness on his/her feet, and the comfort of wearing the shoe is significantly improved. In addition, the midsole according to the modification of this example is
The inner layer foam is divided and joined into each part, and the material and hardness suitable for each part are selected, so the optimal hardness and material for each part are selected appropriately and the parts including the outer layer foam are bonded. Furthermore, it is possible to create a smooth difference in hardness, and by taking advantage of the characteristics of different materials, it is possible to improve the feeling of wearing, cushioning properties, and running performance. Based on the effects of the first embodiment, the midsole in the second embodiment has an inner layer foam (1
) The free foamed EVA exposed on the upper surface mainly compresses and stretches, thereby absorbing and relaxing the bending and stretching force acting on the stepping part, reducing the bending and stretching resistance force on the wearer's feet, and drastically reducing fatigue. The midsole in the third embodiment can further enhance the running functionality of the midsole in the first embodiment. As mentioned above, foamed E, which has a lower hardness than the outer layer foam (2) made of polyester-based foamed polyurethane, is used at the treading part of the midsole where the bending and stretching action is most intense and at the outer edge thereof.
By replacing the inner layer foam (1) made of VA with an appropriate number of protrusions (3), when the stepping part is bent and stretched, the protrusions (3) of the foamed EVA can be easily compressed and expanded. It can alleviate and absorb bending and stretching forces, reduce bending and stretching resistance on the wearer's feet, and dramatically reduce fatigue. In addition, the landing begins almost at the center of the heel, and the stepping movement moves from the small gong ball to the IT ball along the outer leg side, and after the landing is completed, the footwork mainly moves from the second and third foot of the Tsuga ball to the ground. As mentioned above, the heel outer leg side end of the outer layer foam (2) is connected to the protrusion (3) of the inner layer foam (1), which has a lower hardness than the outer layer foam (2).
), when the landing starts from the center of the heel, the protrusion (3) on the lateral leg side of the heel is compressed by the stepping pressure, so the movement of the stepping is moved from the center of the heel to the lateral leg side of the heel. Furthermore, by making the outline width of the end of the outer layer foam (2) on the inner heel push side from the inner heel push side to the arch of the foot wider than the outline width of other parts, The movement of the ankle can be reliably moved along the outer leg side of the heel, which has a more cushioned structure, to the tip, so the movement of the ankle, etc. that occurs when the movement of the foot moves forward along the inner side of the heel, etc., can be avoided. damage could be avoided. Furthermore, the protrusions (3) of the inner layer foam (1) are exposed on both side end faces of the stepping part and the end face on the heel outward push side, and these protrusions (3) are formed in a desired color and an appropriate shape. It becomes a strong accent and can improve the beauty and give a good impression. The midsole of the present invention is comprised of at least two polymeric foam layers mounted between the outsole and the cover, the polymeric foam layers having a contour that roughly follows the outsole, and an elastic inner layer. Since the foam is covered with an outer layer of polyester urethane foam that has a higher hardness than the inner foam, the inner foam has the advantages of excellent cushioning and light weight, and the outer foam has the advantage of being superior in cushioning properties and light weight. The combination of its excellent fracture strength, low compression set, and good recovery ability produces a synergistic effect, and the outer contour width of the bending part and heel part or the inner layer foam By changing the thickness of the partial layers and the shape of each part, it is possible to adjust the desired structure to improve running functions such as flexibility, stiffness, running stability, cushioning landing impact, and preventing internal rotation. can demonstrate.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, (a) is a plan view, (b) is a vertical sectional view thereof, and Fig. 2 shows a second embodiment (C1 is a plan view, f
dl is a longitudinal sectional view, FIG. 3 is a third embodiment, (e) is a plan view, (f) is a side view, and FIG. 4 is a modification of FIG. 1.
(gl is a plan view, (h) is a vertical cross-sectional view, and Figure 5 is a
(J) is a modified version of the figure 1. (h) is a longitudinal cross-sectional view. ,1-)1・
- Inner layer foam, 2... Outer layer foam, 3... Protrusion, 4...
Curved part, 5... Tip part, 6... Upper part, 7... Lower part, 8
...Horseshoe-shaped part, (9)...Tip of heel. Patent Applicant: Tsukisei Kasei Co., Ltd. (Figure 1, Figure 2, Figure 3, Procedural Amendment Statement) January 31, 1985 Patent Application No. 157974, filed in 1982, 2, Title of Invention: Mifu de Sol 3, Relationship with the case of the person making the amendment Patent applicant address 60 Hakusan-cho, Kurume City, Fukuoka Prefecture (830-
91) Telephone (0942) 33-1111 Representative January 8, 1985 (Shipped on January 28, 1986) 5. Subject to amendment

[Brief explanation of the drawing]

6. Change “(h)” to “(K)” on page 15, line 10 of the statement of contents of the amendment.
” I corrected myself.

Claims (1)

[Claims] 1. Consisting of at least two polymer foam layers installed between the outsole and the cover, the polymer foam layer has a contour that approximately follows the bottom of the water, and has elasticity. A midsole characterized in that an inner foam layer with a rough texture is covered with an outer foam layer of polyester-based urethane. 2. The hardness of the inner layer foam is 20 on the Asker hardness tester C type.
~60 degrees, and the hardness of the outer foam is 25 to 80 for the same C type.
2. The midsole according to claim 1, comprising polymeric foam layers having a hardness of 100% and a hardness of the outer foam layer being higher than that of the inner foam layer. 3. The inner layer foam is divided and joined into each part as appropriate, and the material and hardness are suitable for each part.
The midsole according to Items 1 and 2. 4. The midsole according to any one of claims 1 to 3, wherein the upper surface of the outer layer foam corresponding to the stepped portion is cut out, and only the stepped portion is made of two polymer foam layers. 5. A cutout is provided on both sides of the stepping portion of the outer foam layer and/or on the outer heel side of the heel, and the cutout is made of a polymeric foam layer filled with the inner foam layer. The midsole according to items 1 to 3. 6. The midsole according to claims 1 to 3, which has a polymeric foam layer in which the outer foam layer has a larger contour width from the inside of the heel to the foot of the foot and is combined with the inner foam layer.