JPS6232903A - Sponge shoe sole with antiskid material and its production - 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 [Field of Application of the Invention] The present invention relates to a lightweight anti-slip shoe sole and a method of manufacturing the same.

[Background of the invention]

Heretofore, it has been known to integrally mold an unvulcanized or vulcanized solid shoe sole compound with an unvulcanized candy rubber compound in the same mold, with or without an adhesive. Moreover, since the main body of the sole is made of solid rubber with high hardness, the candy rubber (or soft rubber) part has no anti-slip effect unless it protrudes from the ground contact surface of the main body. In addition, in terms of adhesive strength, molded products made of vulcanized solid shoe soles and unvulcanized candy rubber have the disadvantage of low adhesive strength and peeling when repeatedly bent.

In order to join the sponge sole and candy rubber according to the present application, it is conceivable that they are both unvulcanized, but if they are molded at the same time in the same mold, the foam will expand rapidly as soon as the mold is opened. As a result, solid rubber could not handle the expansion of the foam, causing the entire product to warp, resulting in an unusable product. Therefore, we had no choice but to vulcanize the foam and candy rubber in separate molds, and process the foam to create grooves in a part of the ground contact direction. It was considered that the process would involve applying an adhesive to the parts and applying pressure and heat to join them, which would be a very cumbersome and costly operation, but it was difficult to implement due to the complexity of the work. Even if they were bonded using this method, they still had functional defects such as easy peeling when bent and poor adhesive strength.

[Purpose of the invention]

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a shoe sole that is lightweight, non-slip, easy to manufacture, and has an excellent appearance, as well as a suitable method for manufacturing the same.

[Summary of the invention]

The characteristics of the sponge sole of the present invention, which was made for this purpose, is that the main body of the sole is made of rubber foam containing thermoplastic synthetic resin, and candy rubber is integrally molded on a part of the contact surface. It's where you are. Here, thermoplastic synthetic resin is an important constituent requirement, that is, the main body of the sole is a uniform blend of rubber and thermoplastic synthetic resin, and the content of thermoplastic synthetic resin (hereinafter referred to as resin) is At least 5 to 50% of the combined amount of rubber and resin, preferably 2
It is 0-40%.

The reason for this is that in the case of a foam with a rubber content of 100%, the rubber is crosslinked during the initial period of heating and pressure molding the sheet in a mold, so the elasticity during heat softening is large and it does not easily deform. Therefore, when the unvulcanized candy rubber and the sheet were bonded under heat in a mold, the contact surface was not 100 mm wide and protruded.

Next, in the case of a foam with a resin content of 100 cm, when the sheet formed in the mold is heated and pressurized, since it is not cross-linked, it rapidly softens and fluidizes due to the heat, and the unformed parts arranged inside the cavity. Almost no thermocompression bonding force was generated between the vulcanized candy rubber and the design pattern on the candy rubber surface was not clearly designed due to insufficient pressure. However, in foams made from blends of rubber and resin, especially when the resin content is 15% compared to the rubber.
If the foam sheet is between 50% and 50%, the elasticity of the foam sheet when softened by heat is lower than that of 100% rubber, and it is easily deformed by heat in the mold, resulting in poor pressure and adhesion with the candy rubber. If the timing is appropriate, a completely anti-slip sponge sole sheet with a clear pattern on the anti-slip portion can be obtained.

Then, such sponge soles are crimped onto the contact surface of a resin-containing rubber foam having a smooth puff surface or skid surface by partially heating and pressurizing a non-slip candy rubber compound, and then molding as appropriate. The material of the main body of the present invention is a blend of thermoplastic synthetic resin and rubber, and in order to utilize the viscoelasticity of rubber, the content ratio of the resin is 15 to 15. It is preferable to set it to 50 inches, and this suppresses the flow of the candy rubber until the unvulcanized candy rubber is vulcanized when heated and pressurized in the mold, and uniformly spreads over the entire candy rubber. The pressure applied allows the candy rubber to flow throughout the mold cavity.

When referring to candy rubber, candy rubber refers to so-called "pure rubber" compounds with a high rubber content that are transparent or at least translucent, with little or only a small amount of filler added in the rubber compound. .

These candy rubbers have the characteristics of being highly elastic, flexible, and tough rubber.

The material constituting the sole body can be a rubber foam made of natural rubber and all synthetic rubbers such as styrene-butadiene rubber, polybutadiene rubber, and acrylonitrile-butadiene rubber. Rubber raw material, crosslinking agent, blowing agent, filler, and vulcanization aid.

A heated and pressurized foamed material can be used by adding commonly used rubber chemicals such as a softener. Examples of thermoplastic synthetic resins include ethylene vinyl acetate copolymer and vinyl chloride resin.

A polyblend resin of acrylonitrile butadiene rubber and vinyl chloride resin can be used. Thermoplastic synthetic resins are generally extruded.

It is molded by a processing method such as injection molding, but the processing temperature in such cases is 180° C. or higher, and as the temperature increases, it has a characteristic that the rate of thermal softening is extremely fast compared to rubber. The present invention is characterized in that it is applied to the manufacture of sponge shoe soles by utilizing the rapid thermal softening of thermoplastic resin blended with rubber.

The main body of the sole is a foam, and the purpose is to adhere candy rubber, which is solid rubber, to the surface in an unvulcanized state (adhesion in a vulcanized state reduces strength).
It is impossible to mold both in an unvulcanized state in a mold.

This is because when the mold is opened, the foam has a polygonal shape larger than the mold dimensions. In the present invention, a mold filled with material is inserted into a compression molding press and molded by heating and pressurizing, but the press is equipped with a cooling device and the mold can be cooled by cooling water passing through the press heating platen. desirable. This prevents the occurrence of problems such as warping of the entire product after it is taken out, and it also prevents the unvulcanized candy rubber material from being extremely susceptible to shrinkage due to the high temperature of the mold when the mold is in a cooling state. There is no problem of shrinkage or deformation, and it is possible to heat and press the material in a stable state. Therefore, mass production of stable and good products is possible. Note that the rubber foam and the candy rubber are generally of the same vulcanization type.

[Embodiments of the invention]

A rubber foam compound of the following composition was kneaded and molded using a mold.
A rubber foam sheet with a thickness of 0 mm is vulcanized and this is 6 m thick.
Prepare the sole body using a skiving machine to a thickness of .

Rubber foam compounding example Part by weight Copolymer (Toyo-Uda Co., Ltd.) Activated zinc white Zincas 20 (Sakai Chemical Industry Co., Ltd.)
2 Filler Nipsil VN3
25 (Nippon Silikani Co., Ltd.) Stearic acid (Shin Nippon Rika Co., Ltd.) 1.5 activator
Ethylene glycol B2 (Mitsubishi Yuka Co., Ltd.) Organic peroxide Kayakumil D-40K
2.5 (Kayaku Nouri Co., Ltd.) Organic foaming agent Cellmic CAP
2 (Sankyo Kasei Kogyo Co., Ltd.) Pigment Showblack N330
3 (Showa Cabot Co., Ltd.) Total 1 38.0 Physical property value ratio of compound (-)
O, SO hardness Kobunshi Keiki C-type sponge hardness tester (-) 55 Tensile strength (Kgf/cJ)
30 growth (
q6) 3
60 Separately, a candy rubber compound of the following composition was kneaded and then dispensed to a thickness of 1.5 wn and a width of 15. .

Form a belt-shaped sheet.

Candy rubber compound SBR Solbrenna 375 100 (
Asahi Kasei Kogyo Co., Ltd.) Active zinc white Zincas 20
2 (Sakai Chemical Industry Co., Ltd.) Filler Nipsil VN3
10 (Nihon Silikani Gyo Co., Ltd.) Lubricant Stearic acid
1 (Shin Nihon Rika Co., Ltd.) Softener Diana Process Oil PW-3801
0 (Idemitsu Kosan method) Activator ethylene glycol B1.5 (Mitsubishi Yuka Co., Ltd.) Crosslinking agent Kayakumil D-40K
1.5 (Kayaku Nouri Co., Ltd.) Total 126.0 Physical property value specific gravity of the compound (-)
1.07 Hardness JISA type (-)50 Tensile strength (Kyf/ca)
100 growth (%)
The sole body 1, which is a vulcanized rubber foam prepared over 600 times, and the candy rubber band 7 are shown in FIG.
Heat molding is performed using the mold shown in FIG.

In the mold of this example, a weir 5 for preventing the candy rubber from flowing is provided at a predetermined position of the lower mold 4, and the strip-shaped candy rubber 7 is fitted into a cavity 6 for candy rubber provided by this weir 5. death,
After layering the rubber foam sheet 1 thereon, the upper mold 3 is covered. Put the mold into a hydraulic press 16
After increasing the press temperature to 0°C and heating under pressure for 10 minutes, cooling water is introduced into the press heating plate and the mold is cooled for 7 minutes. Pull out the mold and take out the sheet-shaped product (see Figure 1). After that, the next material can be charged into the cooled mold to produce the next product. The produced sheet material is cut into appropriate pieces to form shoe soles shown in FIGS. 5 and 6. In this example, a sheet material punched out with the same anti-slip structure is used for the heel 8 as well.

According to such a non-slip sponge sole, warping does not occur even when the vulcanized foam sheet and the unvulcanized candy rubber compound are simultaneously vulcanized, and the above two materials are heated under pressure at the same time. Therefore, the adhesion at the joints is strong, and the main body of the sole is a blend of rubber and synthetic resin, and because it is foamed, the specific gravity is less than half that of regular solid rubber. It is lightweight, and since it is a composite of extremely soft candy rubber and rubber foam, both are highly flexible, exerting a large amount of ground pressure when worn, and have better anti-slip effects than conventional products. It has much greater advantages than. However, since the candy rubber is partially bonded to the ground surface of the rubber foam in the form of a band or circle, it also has the advantage of giving an elegant feel to the design. In addition, in this example, the mold is equipped with a non-slip part of the candy rubber, so that the unvulcanized candy rubber does not flow during the initial vulcanization period and flow into other parts during heating and pressurization. Candy rubber can be arranged in a predetermined position as a bright design. Therefore, the candy rubber will not flow out to other parts of the contact surface and make the design unsightly.

〔Effect of the invention〕

As described above, the anti-slip shoe sole of the present invention has a sole body made of rubber foam, so it is extremely lightweight, and a plurality of strip-shaped candy rubber sheets are made of rubber foam on the front half of the ground contact surface. Because it is integrally molded and buried, it does not peel off during use and has a strong bond.Both rubber foam and candy rubber are extremely flexible and flexible, so even on easy-to-clean road surfaces, the ground pressure and the above-mentioned It has an anti-slip effect due to the interaction of the flexibility of both.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a product sheet manufactured according to an embodiment of the present invention, Fig. 2 is a perspective view of a rubber foam sheet with a smooth surface before integrally molding anti-slip candy rubber, and Fig. 3 is a perspective view of a product sheet manufactured by an embodiment of the present invention. FIG. 4 is a cross-sectional view of a mold for carrying out the present invention, and FIG. 4 is a cross-sectional view of a mold showing a state in which unvulcanized candy rubber and a rubber foam sheet for anti-slip are charged into the mold. FIG. A diagram showing the final product after punching and joining the heel, and FIG. 6 shows a cross-sectional view of the product after punching. 1... Rubber foam sheet containing thermoplastic synthetic resin 2.
・・Candy rubber for anti-slip 3・・Upper mold 4・・Lower mold 5・・Weir 6 for preventing candy rubber from flowing・・Candy rubber cavity 7・・Candy rubber 8・・・Heel. Figure 2 1

Claims (1)

[Scope of Claims] 1. The main body of the sole is made of rubber foam containing 5 to 50% of thermoplastic synthetic resin evenly dispersed therein, and a part of the contact surface is covered with candy rubber under heat and pressure. A non-slip sponge sole that is fixed by an integrated process. 2. The sponge sole according to claim 1, wherein the contact surfaces of the main body and the candy rubber are substantially flush with each other. 3. Place the unvulcanized candy rubber compound in the weir to prevent flow, which is provided in a part of the ground surface of the lower mold cavity of the upper and lower molds for shoe sole molding, and then place the thermoplastic synthetic resin in 5. A method for producing a non-slip sponge shoe sole, which comprises placing a rubber foam sheet containing ~50% and heat-foaming it in advance, and subjecting it to pressure and heat treatment.