JP2003159101A - Injection molded shoe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molded shoe which can adopt a sole integrated by laminating a synthetic resin including a plasticizer and a different material. <P>SOLUTION: In laminating a midsole 2 of soft polyvinyl chloride including a plasticizer and an outsole 3 of a rubber shoe, a fiber material sheet 4 for blocking movement of the plasticizer and the outsole 3 are integrally pressed to form a cup shape integrated substance 5 with a swollen center part. The integrated substance 5 is positioned in an injection mold 10 and the midsole 2 material is injected into the cavity to the fiber material sheet 4 side to integrate. At least the upper edge part of the outsole of the toe part is made into an upturned form. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection-molded shoe in which a midsole made of a synthetic resin containing a plasticizer and an outsole made of a material different from the midsole are integrated.

[0002]

2. Description of the Related Art Conventionally, as a shoe sole, a rubber sole made of natural rubber or synthetic rubber and a synthetic resin sole made of synthetic resin are known. These shoe soles have been appropriately selected and used depending on the application and manufacturing method of the shoe. Generally, rubber soles have excellent anti-slip properties and are often used in cold weather shoes, and synthetic resin soles are often used in casual shoes. In particular, in a shoe manufacturing method utilizing injection molding, a thermoplastic synthetic resin is often used because it is easy to work and reduce the weight by foaming. On the other hand, in order to improve the functionality and design of shoes, many shoes made of natural rubber or synthetic resin have been manufactured.
For shoes used for running, etc., a midsole made of foamed synthetic resin such as EVA and an outsole with a rubber sole are used to reduce the weight of the shoe and improve its functionality. ing. Even in injection-molded shoes, a foam synthetic resin is used for the midsole and a non-foam synthetic resin is used for the outsole to reduce weight and improve functionality. Polyvinyl chloride, polyurethane, etc. are used as the foamed synthetic resin used for this midsole, and polyvinyl chloride, polyurethane, natural rubber, synthetic rubber, etc. that are not expanded or have different molecular weights are used as the outsole. Has been done.

[0003]

By the way, in the case of polyvinyl chloride, which is most often used as a sole for injection molded shoes, it is common to add a large amount of a plasticizer in order to impart flexibility. . It is known that the plasticizer added to this polyvinyl chloride usually tends to migrate with time.
Therefore, in the case of a shoe sole in which a rubber outsole is integrated with a polyvinyl chloride midsole, even if there is no problem at the beginning of molding, the rubber will swell with the vinyl chloride plasticizer over time, and There is a problem that the physical properties of the sole are deteriorated, and shoes with such a combination have not been produced so much. However, even in injection-molded shoes, different materials such as rubber are used for the outsole to improve various functionalities such as slip resistance and durability, and at the same time, the weight is lighter than that of rubber. There is an increasing demand for the production of shoes that aim to achieve

Therefore, the present invention is intended to enable the adoption of a shoe sole structure capable of integrating a lightweight midsole and an outsole of a different material having various functions such as slip resistance and durability. To aim.

[0005]

In order to achieve the above object, the present invention integrates a synthetic resin midsole containing a plasticizer and an outsole made of a material different from the synthetic resin forming the midsole. In the injection-molded shoe described above, a fiber material sheet that blocks migration of the plasticizer is interposed between the midsole and the outsole.

As described above, a fibrous material sheet for shielding the migration of the plasticizer is provided between the midsole of the synthetic resin containing the plasticizer and the outsole made of a material different from the synthetic resin forming the midsole. By interposing, it is possible to prevent the plasticizer of the midsole from migrating to the outsole, and it is possible to prevent the physical properties of the outsole from being deteriorated by the plasticizer. For this reason, it is possible to use a material with better slip resistance and durability than the synthetic resin of the midsole for the outsole, and for the midsole,
Since it is possible to use synthetic resin that is foamable and has excellent injection moldability, it is possible to reduce the weight of shoes. Here, the synthetic resin containing the plasticizer has excellent injection moldability and can be foam-molded, and examples thereof include polyvinyl chloride, a copolymer of polyvinyl chloride, and generally thermoplastic rubber (TPR). ), A copolymer resin of styrene, ethylene, an acrylic resin and the like and a rubber component such as butadiene and isoprene can be used. Further, as the material of the outsole, natural rubber or synthetic rubber which is more excellent in wear resistance and slip resistance than the above resins can be used. The fiber material sheet that blocks migration of the plasticizer is woven cloth, knitted cloth, or non-woven cloth made of fibers such as cotton, polypropylene, polyester, and nylon, and has one side for increasing the adhesiveness to the midsole or outsole. Alternatively, those having raised hairs or loops on both sides can be preferably used.

As a method for interposing a fibrous material sheet between the midsole and the outsole, for example, the outsole and the fibrous material sheet are previously integrally molded by press molding or the like, It is preferable that the fibrous material sheet is positioned in a state of facing the cavity space of the injection mold, and the midsole molding material is injection-molded in the cavity space. However, the method is not limited to this. By the way, as the form of the outsole, at least like the stepped part and the heel part,
It may be possible to include a place where there is a lot of ground contact with the ground, floor surface, etc., and to provide it locally in these areas, or to include it in all areas on the ground plane side of the midsole. May be.

In the present invention, the fiber material sheet is
It is designed to be integrated beforehand with the adhesive surface of the outsole to the midsole. In this way, if the fiber material sheet is previously integrated with the outsole, the fiber material sheet can be set at a predetermined position of the injection molding mold for molding the midsole, and the midsole molding material can be injected into the cavity. Can be manufactured, which is convenient.

Further, in the present invention, at least the upper edge portion of the toe portion of the outsole is wound up so as to wrap around the midsole. In this way, if at least the upper edge of the toe part of the outsole is rolled up, the joint between the outsole and the midsole is less likely to come into contact with the ground, floor, etc. during walking, etc. Less likely to occur. Since the upper edge of the outsole is rolled up, for example, if the integrated outsole and the fibrous material sheet, which are previously formed by press forming, are formed into a cup shape, the outsole can be easily formed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an explanatory view of an injection-molded shoe according to the present invention, FIG. 2 is an explanatory view of an integrated outsole and a fiber material sheet, (a) is a side view, (b) is a bottom view, (c). Is a cross-sectional view taken along the line A-A of (b), FIG. 3 is an explanatory view when the midsole is injection-molded, FIG. 4 is a state diagram of the shoe after injection-molding, and FIG. 5 is a state diagram of the finished shoe. .

As shown in FIG. 1, an injection-molded shoe 1 according to the present invention is made by stacking a synthetic resin midsole 2 containing a plasticizer and an outsole 3 made of a different material to reduce the weight of the shoe sole. At the same time, it is intended to improve the slip resistance, and at this time, by interposing a fiber material sheet 4 between the midsole 2 and the outsole 3 that shields the migration of the plasticizer, the outsole 3 is prevented from deterioration. I am trying to.

Here, in the case of this embodiment, the midsole 2 is used.
As the material, a soft polyvinyl chloride resin is used, and the outsole 3 is made of rubber. Further, as the fibrous material sheet 4, a woven cloth, a knitted cloth, a non-woven cloth or the like having raised or looped surfaces on both sides can be applied.

An example of a method of molding such an injection molded shoe 1 will be described. First, the outsole 3 and the fiber material sheet 4 are integrated by press molding to form an integrated product 5. At this time, as shown in FIG. 2, the fibrous material sheet 4 is made slightly larger than the desired shape of the outsole 3 and the rubber raw material is vulcanized by embossing it into a cup shape having a depressed central portion. The fibrous material sheet 4 is placed inside the cup shape, and the ears m are integrated in such a state that they extend beyond the desired shape of the outsole 3 as an extra protrusion amount. Also, especially on the toe side and heel side,
The upper edge portion is curved upward toward the front or the rear.

When the integrated product 5 is molded, the integrated product 5 is set in the injection mold 10 as shown in FIG. That is, the cover 6 is hung on the last mold 13, and the fiber material sheet 4 of the integrated product 5 is set to the cavity C side at a predetermined position of the bottom mold 11, and the bottom mold 11 and the side mold 12 are used to set the ear part. m
Position by sandwiching. And in this way ear m
It can be positioned at an accurate position by sandwiching.

Next, a soft polyvinyl chloride resin material is injected into the cavity C space to mold the midsole 2. Then, when the injection material is cooled and solidified and taken out from the injection mold 10, a shoe 1 as shown in FIG. 4 is formed, and an extra ear portion m is projected on the shoe 1. Then, by cutting off the ear portion m, the injection-molded shoe 1 as shown in FIG. 5 is completed.

Injection-molded shoes 1 produced as described above
Is a form in which the upper edge of the outsole 3 of the same portion is rolled up so as to wrap the midsole 2 by forming the integrated body 5 into a cup shape in advance and bending the toe side and the heel side upward. Then, the joint portion between the outsole 3 and the midsole 2 is located at a position where it is difficult to contact the ground or the floor surface when walking. Therefore, the bonded portion is less likely to peel off. Further, since the soft polyvinyl chloride resin and the rubber are laminated, the structure is lightweight and has excellent slip resistance, and the outsole 3 does not easily deteriorate due to the intermediate fiber material sheet 4.

By the way, in the above embodiment, the outsole 3 is provided over the entire area of the midsole 2 on the ground contact side, but the form of the outsole 3 is at least in the toe part and the heel part. It may be of a form provided locally. Also in this case, the same effect is obtained.

The present invention is not limited to the above embodiment. Those having substantially the same configurations as those described in the claims of the present invention and exhibiting the same operational effects belong to the technical scope of the present invention. For example, the material of the midsole 2 can be applied to other synthetic resins containing a plasticizer in addition to soft polyvinyl chloride. Further, the top edge of the outsole 3 may be rolled up upward only at the toe.

[0019]

As described above, in the injection-molded shoe according to the present invention, the midsole of the synthetic resin containing the plasticizer and the outsole made of a material different from the material forming the midsole are integrated. In injection-molded shoes, a fiber material sheet that blocks migration of the plasticizer is inserted between the midsole and the outsole, so even if the outsole is made of rubber, there is no risk of deterioration due to migration of the plasticizer. The weight of the shoe sole can be reduced, the abrasion resistance can be improved, and the anti-slip effect can be improved. At this time, if the fiber material sheet is previously integrated with the outsole, the shoe can be manufactured simply by setting it in the injection mold for molding the midsole and performing the injection molding. Also, if at least the upper edge of the toe part of the outsole is rolled up, the joint between the outsole and the midsole will be less likely to come into contact with the ground or floor when walking, etc. Is less likely to occur.

[Brief description of drawings]

FIG. 1 is an explanatory view of an injection-molded shoe according to the present invention.

FIG. 2 is an explanatory view of an integrated outsole and a fibrous material sheet, in which (a) is a side view, (b) is a bottom view, and (c) is a sectional view taken along the line AA of (b).

FIG. 3 is an explanatory diagram for injection molding the midsole.

[Fig. 4] State diagram of shoes after injection molding

[Figure 5] State diagram of the finished shoe

[Explanation of symbols]

1 ... Injection molding shoes, 2 ... Midsole, 3 ... Outsole, 4 ... Fiber material sheet, 10 ... Injection mold.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masao Tamura             3208-3 Akami Town, Sano City, Tochigi Prefecture F-term (reference) 4F050 AA03 BA55 CA01 HA20 HA57

Claims (3)

[Claims] 1. An injection-molded shoe in which a midsole made of a synthetic resin containing a plasticizer and an outsole made of a material different from the synthetic resin forming the midsole are integrated. An injection-molded shoe, in which a fibrous material sheet that blocks migration of a plasticizer is interposed therebetween. 2. The injection-molded shoe according to claim 1, wherein the fibrous material sheet is preliminarily integrated with a bonding surface of the outsole to the midsole. 3. The method according to claim 1, wherein at least an upper edge portion of the toe portion of the outsole is wound up so as to wrap around the midsole.
Injection-molded shoes described in.