JP2011083481A - Antistatic shoes - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide antistatic shoes, which are formed by injection molding only, without requiring time-consuming assembling processes. <P>SOLUTION: The antistatic shoes include an upper member to compose a foot insertion part, and a shoe sole provided under the upper member. The upper member and the shoe sole are formed by injection molding using foam resin for material. At the time of forming the shoe sole, a continuity part is provided through the upper member inner surface side of the shoe sole and the shoe sole surface side. An inner sole member exposed on an inner surface of the upper member and a grounding member exposed on a shoe sole surface are formed by injection-molding of material having conductivity as they are joined or integrally combined through the continuity part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an antistatic shoe that discharges static electricity charged by a human body through a floor surface.

Measures against static electricity in electronic parts manufacturing sites, precision equipment sites, flammable materials handling sites, etc. to prevent damage to electronic components and equipment due to momentary discharge of static electricity charged to the human body, fire accidents, etc. is required.
As one of countermeasures against static electricity, antistatic shoes that remove static electricity charged on the human body without sparking are used. Examples of the antistatic shoes include shoes having various structures shown in Patent Documents 1 and 2 and the like that include means for electrically connecting the inside of the shoe to the surface of the shoe bottom. In the case of such an antistatic shoe, it is often performed that a conductive member is formed of a conductive cloth or the like as a means for conducting the inside of the shoe and the surface of the shoe sole, and the conductive member is incorporated in the midsole. .

  The reason why cloth is often used as the conductive means is that the portion containing the conductive means is a part that is deformed such as bent, stretched or contracted, and the conductive means itself is soft from the viewpoint of preventing electrical disconnection. This is because it needs to be formed of a deformable material.

Japanese Patent No. 3521314 Japanese Patent No. 3527643

However, in order to incorporate the flexible conductive means into the inside of the shoe sole, a conductive means and a means for holding the conductive means are required, and a time-consuming process such as assembly work is also required.
This invention is invented in view of the said subject, Comprising: It provides an antistatic shoe which can be formed only by injection molding, without requiring a time-consuming assembly process.
In addition, the weight of the shoe is reduced by integrally forming the upper body, which is a foot pocket, and the midsole that occupies most of the shoe sole by injection molding with a lightweight foamed resin material such as EVA. However, it is an object of the present invention to provide an antistatic shoe capable of discharging a charge charged to a human body through a shoe bottom surface.

In order to solve the above problems, the present invention has the following configuration. That is,
An antistatic shoe having an upper body constituting a foot pocket and a shoe sole provided at a lower portion of the upper body,
The upper body and the shoe sole are formed by injection molding using a foamed resin as a raw material, and at the time of the shoe sole formation, a communication portion that penetrates the upper body inner surface side and the bottom surface side of the shoe sole is provided,
The insole member exposed on the inner surface of the upper body and the grounding member exposed on the shoe bottom surface are formed by injection molding in a state of being joined or integrally joined via the communicating portion with a conductive material. It is characterized by.

In the antistatic shoe, the foamed resin material is EVA resin, and the conductive material is rubber mixed with a conductive material.

The antistatic shoe according to the present invention can be formed by using an EVA resin in which most of the material constituting the shoe is first foamed, and thus has an effect that it can be formed very lightly. In addition, since the conductive part for exhibiting the antistatic function can be formed by injection molding, it is necessary to incorporate a conductive component incorporated in the shoe while it is a shoe mainly made of EVA resin having extremely low conductivity. This has the effect that the number of manufacturing steps can be reduced.
Furthermore, since the shape of the outsole portion that becomes the conductive portion can be formed by injection molding using a mold, it has an effect that it can be formed in various designs in consideration of aesthetics.
In addition, the foamed resin that forms the majority of the upper body and the shoe sole and the rubber that forms the conductive part are joined by the contact and coagulation of a fluid material during injection molding without using an adhesive. It is. Therefore, since the strength of the joint portion is high and it is difficult to peel off, there is an effect that the durability of the shoe is not impaired.

1 is a cross-sectional view of an antistatic shoe according to the present invention. 1 is a bottom view of an antistatic shoe according to the present invention. 1 is a cross-sectional view of a molding die for forming an antistatic shoe according to the present invention. It is explanatory drawing of the shaping die for forming the antistatic shoe which concerns on this invention. It is explanatory drawing of the primary molding formed with the shaping die. It is sectional drawing of the primary molding formed with the shaping die. It is explanatory drawing regarding the formation process of the antistatic shoe which concerns on this invention. It is sectional drawing showing the state which attached | subjected the primary molding to the molding die which removed the nesting. It is sectional drawing showing the state which carries out the injection molding of the electroconductive raw material to a primary molding. It is explanatory drawing showing the design of the electroconductive part of the antistatic shoe which concerns on this invention. It is explanatory drawing showing the other form of the antistatic shoe which concerns on this invention.

Hereinafter, modes for carrying out the present invention will be described. FIG. 1 shows a sectional view of an antistatic shoe 1 according to an embodiment of the present invention.
The anti-static shoe 1 includes an upper body 2 that forms a bag-like foot insertion portion and a shoe sole 3 provided below the upper body 2 in the same manner as a general shoe. The main parts of the upper body 2 and the shoe sole 3 are formed by injection molding using a mold using a foamed EVA (ethylene vinyl acetate) resin as a molding material.

  The bottom of the shoe sole 3 is provided with a grounding portion 4 for contact with a walking surface made of conductive rubber or resin material. Further, an inner bottom portion 5 made of conductive rubber or resin material is also provided on the inner surface of the upper body 2 that is integrated with the shoe sole 3. The grounding portion 4 and the middle bottom portion 5 are formed of conductive rubber or resin material and are electrically connected to each other at the connecting portion 6.

FIG. 2 is a bottom view of the antistatic shoe 1 as seen from the bottom side. The shoe shown in FIG. 2 is formed by providing a ground contact portion 4 in contact with the floor surface in an inner region excluding the outer peripheral edge of the ground contact surface. The grounding portion 4 shown in FIG. 2 represents a case where it is formed as a flat surface without a pattern as an example, but there is no problem even if unevenness, grooves, etc. for preventing slipping are provided as in general shoes. It is.
The rubber or resin material constituting the grounding part 4 and the middle bottom part 5 is adjusted so that the electrical resistance between the grounding part 4 and the middle bottom part 5 is about 10 ⁵ to 10 ⁹ ohms by kneading a conductive material such as carbon. Thus, a flexible conductor is formed. With this configuration, the antistatic shoe 1 can be formed with a single member from the place of contact with the user (the upper surface of the midsole portion 5) to the bottom surface of the grounding portion 4, as in Patent Documents 1 and 2 above. Since the structure is not a combination of a plurality of conductive members, it is easy to keep the electric resistance constant. The reason why the resistance value is set to the above-mentioned value is to allow the electric charge charged to the body of the wearer to be conducted without an abrupt discharge.

Next, in order to describe the structure of the antistatic shoe 1 in more detail, an example of a manufacturing procedure will be described.
3 and 4 are schematic views showing an example of a mold device used when forming the antistatic shoe 1. As a main structure, the mold apparatus has a side mold 10 for forming the upper surface of the shoe, a bottom mold 11 for forming the shoe sole portion, and a last mold 12 in the shape of a foot for forming an interior space of the shoe. is doing.
A pattern mold 13 is fitted into the bottom mold 11 to form a concave / convex pattern on the bottom surface of the shoe, and the bottom surface of the shoe having a predetermined pattern is formed by fitting the pattern mold 13 into the bottom mold 11. Be able to. The pattern mold 13 to be mounted on the bottom mold 11 is prepared with a plurality of types having different patterns so that a shoe bottom shape suitable for each shoe can be formed by exchanging depending on the application. It has become.

Further, nested molds 14 and 15 are arranged between the bottom surface of the last mold 12 having a foot shape and the pattern mold 13. The nesting die 14 is for forming a molding space that forms an insole provided in the bottom portion inside the shoe, and the nesting die 15 is for forming a molding space that forms an outsole portion serving as a grounding portion. belongs to. The illustrated nesting molds 14 and 15 both have an elongated flat surface portion resembling the contour of the sole, and the flat surface portions are arranged so as to contact the bottom surface of the last mold 12 and the surface of the pattern mold 13, respectively. is doing.
The shapes of the nesting molds 14 and 15 that contact the bottom surface of the last mold 12 and the surface of the pattern mold 13 are not limited to the above-described contour shape of the sole.
Further, the nesting die 14 and the nesting die 15 are fitted or joined to each other at the engaging portions 16 and 17 provided in the portion corresponding to the arch. And a molding space 18 for forming the connecting portion 6 of the outsole provided between the inner bottom surface and the shoe bottom surface.

  When all the molds are arranged at predetermined positions, a molding space 19 shown in FIG. 3 is formed in which the heel part and the forefoot part are communicated. The molding space 19 is a continuous molding space that forms the upper body 2 and the midsole portion of the shoe sole 3 formed below the upper body 2. The midsole is an intermediate layer formed between the outsole that forms the main part of the ground contact surface and the upper body 2, and generally forms a cushion layer for mitigating impact.

EVA resin (foamed resin) containing a foaming agent is injected into the molding space 19 through the gate 20 (see FIG. 5). Next, after injecting the EVA resin, the mold is opened and the molded product (primary molded product) A of the EVA resin attached to the last mold 12 is once removed (see FIG. 6). At this time, since the nesting molds 14 and 15 are attached to the removed primary molding A, the nesting molds 14 and 15 are removed (see FIG. 7).
Then, the primary molded product A from which the nesting molds 14 and 15 have been removed is mounted again in the molding space formed by the side mold 10, the bottom mold 11, and the last mold 12 (see FIG. 8), and conductive through the gate 21. The rubber mixed with the substance is injected (see FIG. 9).
The injected rubber material is filled in the space formed by the removal of the removed nesting molds 14 and 15, and the middle bottom portion 5 which is the upper surface of the midsole and the grounding portion 4 (outsole) which is the lower surface of the midsole are filled. Form. When the above steps are completed, the antistatic shoe 1 shown in FIG. 1 is formed.

In the antistatic shoe 1, the middle bottom portion 5 and the grounding portion 4 are electrically connected to each other by a conductive rubber whose resistance value is adjusted to a predetermined value. Can be discharged slowly.
In addition, although an insole is usually placed on the upper surface of the insole portion 5 inside the shoe (not shown), when placing the insole, means for electrically conducting both the front and back surfaces are also provided in the insole.

Next, a design pattern of the conductive grounding portion 4 (outsole) will be described. The ground contact portion pattern on the bottom of the shoe shown in FIG. 2 is formed so as to cover almost the entire shoe sole except for the outer peripheral portion, but may take various forms as shown in FIG.
10A to 10E exemplify different outsole grounding patterns. The grounding pattern of each outsole can be changed as appropriate by changing the shape of the nested mold 15 or the pattern mold 13 described above. The shape can be changed. The mold used in the present invention also has a feature that it can provide a variety of shoes in spite of few replacement parts.

The shoe 1a shown in FIG. 10 (a) has a grounding portion 22 having a shape in which a large number of narrow grounding portions are provided radially around the connection portion 6a of the arch portion of the shoe bottom.
The shoe 1b shown in FIG. 10 (b) is provided with a large number of narrow grounding portions 23 that are narrower than the above-described shoe 1a around the connection portion 6b of the arch portion of the shoe bottom. The circular grounding part 24 with a large area is provided in these places.
A shoe 1c shown in FIG. 10 (c) is provided with an elliptical grounding portion 25 around the connection portion 6c near the arch portion of the shoe bottom.
The shoe 1d shown in FIG. 10 (d) is provided with narrow grounding portions 26a and 26b extending in the front-rear direction around the connection portion 6d of the arch portion of the shoe bottom, and each of the forefoot portion and the heel portion is provided. Substantially circular grounding portions 27a and 27b are provided.
A shoe 1e shown in FIG. 10 (e) is an application example of the grounding portion 4 provided on the shoe 1, and a honeycomb-shaped grounding portion in which a large number of regular connecting portions 6e and hexagonal convex edges 28 are connected. Are provided.
As described above, there are various forms of the shape of the grounding portion formed as the conductive portion, and a design considering aesthetics is possible. In the above-described embodiment, an example in which the grounding portion 4 and the midsole portion 5 are integrally formed has been described. However, the embodiment of the present invention is not limited thereto, and the grounding portion 4 and the midsole portion in the connecting portion 6 are provided. 5 (for example, a structure provided with an engaging portion 6a and an engaged portion 6b as shown in FIG. 11). In this case, the grounding portion 4 and the midsole portion 5 are not molded integrally, but are each molded in advance and then attached to the shoe sole 3.
Alternatively, the bottom 5 may be injection molded with the insert 15 inserted, and the grounding portion 4 may be injection molded after the insert 15 is removed. Further, urethane foam may be used for the foamed resin forming the main parts of the upper body and the shoe sole, and there is no problem even if it is replaced with foam rubber depending on the specification environment.

  The present invention is applicable to antistatic shoes.

1 Antistatic shoes 2 Upper body 3 Shoe sole 4 Grounding part (outsole)
DESCRIPTION OF SYMBOLS 5 Middle bottom part 6 Connection part 10 Mold side mold 11 Bottom mold 12 Last mold 13 Pattern mold 14, 15 Nesting type | mold 16, 17 Engagement part 18 Molding space 19 Molding space 20 Gate

Claims (2)

An antistatic shoe having an upper body constituting a foot pocket and a shoe sole provided at a lower portion of the upper body,
The upper body and the shoe sole are formed by injection molding using a foamed resin as a raw material, and at the time of the shoe sole formation, a communication portion that penetrates the upper body inner surface side and the bottom surface side of the shoe sole is provided,
The insole member exposed on the inner surface of the upper body and the grounding member exposed on the shoe bottom surface are formed by injection molding in a state of being joined or integrally joined via the communicating portion with a conductive material. Antistatic shoes characterized by. The antistatic shoe according to claim 1, wherein the foamed resin material is EVA resin, and the conductive material is rubber mixed with a conductive material.

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