JP6621587B2 - Exothermic rubber - Google Patents

Description

The present invention is characterized in that it increases the heat generation amount of the shoe material caused by the bending movement of the shoe that occurs during walking more than usual, thereby blocking the cool air transmitted from the outside and making the inside of the shoe warmer. It relates to exothermic rubber.

  As a means of warming the inside of shoes, a heating element composition mainly composed of metal powder such as iron powder and footwear that inserts a warmer using the reaction heat of oxygen in the air were used. May shift and lack grip, or the bag may be broken by impact and the exothermic composition may leak. In order to solve the problem and prevent the exothermic composition from leaking out in the shoe, Japanese Patent Laid-Open No. 2001-070009 including a recess for storing a warmer is disclosed.

Japanese Patent Laid-Open No. 2001-190306 discloses that a shoe is warmed by incorporating a heating element in an insole and energizing the heating element with a battery.

Japanese Patent Laid-Open No. 2001-070009 JP 2001-190306 A

Thus, as an electric foot warmer that warms the inside of a shoe, a device equipped with a heating element such as a heater or a technique using a heating composition such as a warmer has been disclosed, but all of them are for heating. Incorporating the above devices and warming materials into the soles and shoe uppers impairs the design and increases the weight of the shoes, which makes it comfortable and different from ordinary shoes. There was a sense of resistance.
In addition, the effect of warming the inside of the shoes is limited, and it is not practical because it takes time and effort to replace the body warmer or charge the power source after a certain period of time.
Therefore, there has been a demand for footwear that can warm the inside of a shoe by generating heat from a part of a shoe that is normally used in a design that is no different from a normal shoe that does not require replacement of a heat source.

It is well known that viscoelastic bodies represented by rubber are released when heat is applied from the outside to deform a part of the applied energy. It is known that the amount of heat released (calorific value) at this time is generally related to the loss factor (tanδ) and the storage elastic modulus of the rubber. Examples include seismic isolation rubber.
Various polymers are used for anti-vibration rubber and seismic isolation rubber, but the vibration energy can be easily converted into thermal energy by increasing the tanδ of the rubber and increasing the amount of heat generated.
This time, we investigated the development of shoes that can prevent the cold air transmitted from the feet with the rubber material that generates heat by increasing the thermal energy of the rubber material generated by the bending of the shoes during walking.

Made from a rubber composition glass fiber is blended so as to be arranged toward the toe direction from the heel, the rubber composition generates heat by adding bending deformation in the length direction perpendicular to the direction of the glass fibers, arrangement direction of the glass fiber is blended into the rubber composition, the toe direction from the heel than in the case other than toward the heel, including the case of vertical toe direction, the calorific value is increased, heat generation Shoes with rubber in the bent position.

Shoe characterized in that the heat generation rubber of the described is disposed relative to the longitudinal length of the shoe, to position 55 to 85 percent heel.

A structure with a high calorific value is a structure with a lot of energy released from the rubber material. Generally, vulcanized rubber is deformed by applying force, and returns to its original shape when the applied force is released. This is because the rubber material can store a part of energy given from the outside as energy when returning to the shape before deformation. At this time, a part of the applied energy is used to return to the state before the deformation, and the remaining energy is released as heat. That is, as the energy released from the rubber material increases, the rubber generates heat.

When a hard fiber such as glass fiber is added to the rubber material and deformed, a greater force is applied to the end of the glass fiber than elsewhere, and heat generation is likely to occur. Since glass fiber is a very thin fiber, the calorific value per glass fiber is small, but when a certain amount or more of glass fiber is added, the glass fiber ends can be made innumerable in the rubber. By generating an infinite number of places where heat is generated, the amount of heat generated by the rubber material increases.

  In addition, the amount of heat generated by a rubber material containing high-hardness fibers (glass fibers) varies depending on the direction of deformation. Generally, fibers added to rubber have the property of being oriented in parallel with the rolling direction when rolled. As a result, the glass fibers in the rolled rubber are oriented in a certain direction. Since the glass fiber is cylindrical, if a deformation is applied in the direction perpendicular to the length direction of the glass fiber, the force applied to the fiber end increases and the amount of heat generation increases.

A rubber composition containing glass fiber generates heat at a position where deformation such as compression, extension, bending and the like occurs. In order to further increase the effect of heat generation, the glass fibers are preferably oriented perpendicular to the direction of deformation.

In the heat-generating rubber of the present invention, the glass fiber is disposed perpendicular to the bending direction of the shoe, so that the amount of heat generated is larger than that when ordinary rubber performs the bending motion. It is preferable to arrange.

By arranging the heat-generating rubber of the present invention at a position of 55 to 85% from the heel with respect to the length in the longitudinal direction of the shoe, it is possible to obtain a heat-generating effect by the heat-generating rubber flexing during normal walking. It becomes. Even if exothermic rubber is placed in other places, the bending motion by walking is small, and the effect of raising the temperature in the shoe is hardly seen.

The amount of glass fiber contained in the exothermic rubber of the present invention is preferably 5 to 50 PHR. If it is 5 PHR or less, the amount of heat generated is small, and if it is 50 PHR or more, rubber kneading work becomes difficult.

The diameter of the glass fiber used for the heat-generating rubber of the present invention is preferably in the range of 10 μm to 300 μm. When the diameter is 10 μm or less, the effect of heat generation is reduced.

The base rubber used in the heat-generating rubber of the present invention is a rubber composition using one or more diene rubbers selected from sulfur-crosslinked natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, and the like. Is preferred.

The length in the longitudinal direction of the shoe described in the present invention is the length from the shoe's heel to the toe, and the position 55 to 85% from the heel in the longitudinal direction of the shoe is usually in walking. This is the place where the flexion movement of shoes is most likely to occur.

By using the shoe part using the heat-generating rubber of the present invention at the shoe bending position, the heat-generating rubber performs a bending movement by walking movement, so that the calorific value is larger than that of the conventional shoe part, so the design is also good. It has become possible to provide warm and comfortable shoes that are light and comfortable to wear, the same as general shoe shapes.

Thermographic temperature distribution before the bending test of exothermic rubber and general rubber at -10 ° C. Thermographic temperature distribution 3 minutes after start of bending test of exothermic rubber and general rubber at -10 ° C.

The exothermic rubber of the present invention can be used for parts relating to shoe production such as a shoe sole, an insole, an insole, a shoe upper, etc. that are easily bent during walking.

According to Table 1, glass fiber is oriented in a direction parallel to the rolling direction by adding high-hardness fibers (glass fibers) to the rubber fabric and kneading and rolling. Therefore, the rolled rubber fabric is turned into a sheet-shaped mold. The glass fiber was set so as to be arranged in the same direction and subjected to hot compression molding to obtain a heat-generating rubber sheet having a thickness of 3 mm. At this time, a glass fiber having a diameter of 10 μm was used. In the same operation, a general rubber sheet with a thickness of 3 mm was also prepared.

The prepared exothermic rubber sheet and general rubber sheet are made into a test piece with a width of 70 mm, a length of 150 mm, and a thickness of 3 mm, and set in a demarcation bending tester in a freezer at room temperature −10 ° C., bending angle 45 °, 300 times per minute A repeated bending test was performed to compare the heat generation temperatures of the test pieces. The test piece of the heat-generating rubber sheet was attached to a demarcation bending test machine so that the glass fiber was perpendicular to the bending position, and the bending test was started after the surface temperature of each test piece reached -10 ° C. At the same time, the surface temperatures of the exothermic rubber sheet and the general rubber sheet were measured by thermography, and each surface temperature was measured for 18 minutes to compare the difference in exothermic temperature. When the results are shown in Table 2, it was confirmed that the surface temperature of the exothermic rubber sheet generated heat up to 7 ° C. higher than that of the general rubber sheet.

1 and 2 show thermographic images of the surface of general rubber and heat-generating rubber sheet before and after the bending test.
Figure 1 shows the temperature distribution of heat-generating rubber, general rubber, and thermography before the bending test. FIG. 2 shows the heat generation rubber, the general rubber, and the thermography temperature distribution 3 minutes after the start of the bending test. In each figure, the left is the general rubber and the right is the heat generation rubber.

From this result, since the heat-generating rubber of the present invention is disposed at the bent position of the shoe, the heat-generating rubber generates heat at a temperature higher than that of a normal rubber material during walking. It was confirmed that the temperature inside the shoe can be kept higher than before by using it.

Claims (2)

It is composed of a rubber composition in which glass fibers having a diameter of 10 μm to 300 μm are blended so as to be arranged from the heel toward the toe direction,
Before Symbol rubber composition generates heat by adding bending deformation in the length direction perpendicular to the direction of the glass fibers,
Compared to the case where the glass fiber compounded in the rubber composition has an arrangement direction other than from the heel to the toe direction, including a case perpendicular to the heel to toe direction, the calorific value increases .
Shoes with a fever rubber in the bent position. The shoe according to claim 1, wherein the heat-generating rubber according to claim 1 is disposed at a position of 55 to 85% from the heel with respect to the length in the longitudinal direction of the shoe.