JP3270387B2 - Foam for shoe sole - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam for shoe soles having excellent wet grip properties.

[0002]

2. Description of the Related Art The bottom surface (ground contact surface) of sports shoes and casual shoes is required to have wet grip properties in rainy weather or the like. In the sole of the shoe, the wet grip property is enhanced by devising the unevenness (design) of the contact surface, but as the wear of the contact surface progresses, the wet grip property deteriorates with time. The cell wall 1 constituting the cell (hollow portion) 10 shown in FIG.
1 exhibits a scratching effect, and at the same time, moisture and oil on the floor and the like escape into the cell 10, so that wet grip performance is generally higher than that of a solid member. On the other hand, there has been proposed a shoe sole in which seed shells such as rice hulls and walnut shells are blended with solid rubber to improve the wet grip property by the spike effect of these seed shells (for example, see Japanese Patent Application Laid-Open No. Hei 5 (1999)). -154005 and 6-100732).

[0003]

However, a sufficient effect cannot be obtained only by the wet grip property of the cells or cell walls of the foam. On the other hand, since solid rubber is heavy, it is not suitable for sports shoes requiring lightness. Therefore, an object of the present invention is to provide a foam for shoe soles which is lightweight, has excellent wet grip properties, and whose wet grip properties are not easily deteriorated with time.

[0004]

In order to achieve the above object, a foam for shoe soles according to the present invention provides a seed shell having an average particle size of 1.
A crushed material having a size of 0 mm or less is compounded, and the crushed material is added to a weight of 100 parts by weight of rubber and / or resin in a weight of 0.05 weight
It is blended in an amount of at least 2.0 parts by weight .

[0005]

Next, the reason why the wet grip property is improved by the present invention will be described. When this foam is used for a shoe sole, before use, the surface 12 is flat as shown in FIG. 1 (a), but the texture of the surface 12 is cut off by the road surface while wearing the shoes, and FIG. Seed shell 1 as in b)
3 and cell 10 are exposed. As is known, the seed shell 13 enhances wet grip properties by a spike effect.

In particular, since the seed shell 13 has low wettability (adhesion) with the matrix 14 of rubber or resin,
(B) As shown in FIG.
Escape, so that the cell 10 is made of a conventional foam (FIG. 1).
(See (a)). Therefore, cell 10
The spike effect by the cell walls 11 around the periphery is improved. In addition, as the cell 10 becomes larger, moisture and oil easily escape into the cell 10, so that wet grip performance is improved. In addition, since the effects of the cell 10 and the cell wall 11 are obtained even after the seed shell 13 slides down, stable anti-slip properties can be expected.

[0007] In the present invention, the reason for using seed hulls as the crushed material is that the effect is not obtained with crushed leather or rubber, and the desired shape and size are obtained with crushed resin. In addition, minerals such as silica sand have extremely poor compatibility (adhesion) with the matrix and damage the floor surface.

As seed shells, walnut shells or cereal husks of the grass family can be preferably used. Here, as the cereals of the Poaceae family, there are rice, wheat, fin, foam, acne and kolyan (a kind of sorghum), but rice husks, that is, rice husks, are most preferable because they are easily available. In addition, the grain shell refers to a portion corresponding to rice chaff in wheat or the like.

If the wettability (adhesion) is too bad depending on the type of the matrix or the seed shell (if necessary), before adding the seed shell, a product such as Desmodur R, Desmodur RF or MDI is required. The seed shell or the crushed material may be immersed in an organic solvent solution of a polyfunctional isocyanate compound called by a name or a common name, and then dried and treated.

The average particle size of the crushed product of the present invention is set to 1.0 mm or less. If the average particle size is too large, the particles will easily slide down due to the external force acting on the particles (crushed material), failing to provide sufficient anti-slip properties, and lowering the tensile strength of the foam, resulting in poor wear resistance. This is because it is significantly reduced. On the other hand, if the particle diameter is too small, sufficient slip resistance cannot be obtained. From this viewpoint, the average particle size of the crushed product is preferably from 10 to 600 µm, more preferably from 30 to 300 µm, and still more preferably from 30 to 250 µm.

[0011] raw material rubber and / or resin 100 parts by weight (raw rubber and / or polymer 100 parts by weight of the resin)
Respect, the added pressure of Muller product is more than 7.5 parts by weight, the tensile strength of the foam is not only remarkably lower, wet grip performance is also lowered. It is presumed that such a decrease in wet grip performance is caused by an increase in the amount of the crushed material, an excessive increase in the proportion of cells that have become large, and a decrease in the contact area. In the present invention, the amount of the powder
Set to 2.0 parts by weight or less.

[0012] Therefore , from the viewpoint of the above-mentioned wet grip property and tensile strength, the added amount of the crushed material is preferably less than 3.0 parts by weight, more preferably 0.5 part by weight or less. In addition, the present onset in order to exhibit sufficient wet grip performance
In the light, the addition amount of the crushed material is set to 0.05 parts by weight or more .

The rubber and resin constituting the matrix of the present invention include natural rubber, SBR, BR, I
In addition to diene rubbers such as R and NBR, and synthetic rubbers such as EPDM and EPM, BR (syndiotactic 1,2-polybutadiene) and EVA (ethylene-vinyl acetate copolymer)
These resins can be used alone or in a blend. In the present invention, when a raw material rubber or resin is blended and used, the amount of the crushed material is the amount added to 100 parts by weight of the total amount of the raw material rubber or resin.

[0014]

EXAMPLES Hereinafter, test examples will be shown to clarify the effects of the present invention. Comparative Example 1 A foam was obtained by adjusting the molding time so that the specific gravity was in the range of 0.55 to 0.60 in the composition of the matrix shown in Table 1 below. In addition, a urea compound was used as a foaming agent.

[0015]

[Table 1]

Examples 1 to 5 and Test Examples 1 to 4 : 0.1 to 1 crushed rice husks per 100 parts by weight of raw rubber
A foam was obtained by molding in the same manner as in Comparative Example 1 except that 5.0 parts by weight was added. The average particle size of the crushed material is 150 μm
Was used. Examples 10 to 11: Except for using those having an average particle diameter of 200 μm, foams were obtained in the same manner as in Examples 1 to 5 . Comparative Example 2: A foam was obtained in the same manner as in Comparative Example 1 except that the design (unevenness) of the shoe sole was changed. Examples 20 to 23: For 100 parts by weight of raw rubber, 0.2 g of ground walnut
A foam was obtained by molding in the same manner as in Comparative Example 1 except that the addition of 〜2.0 parts by weight. The average particle size of the crushed material is 175μ
m. Examples 31 to 34: For 100 parts by weight of raw rubber, crushed rice hulls were added in an amount of 0.2 to
A foam was obtained by molding in the same manner as in Comparative Example 1 except that 2.0 parts by weight was added. The average particle diameter of the rice hulls was 40 μm. Examples 41 to 43: For 100 parts by weight of raw rubber, the crushed rice hulls were added in an amount of 0.2 to
A foam was obtained by molding in the same manner as in Comparative Example 1 except that 1.0 part by weight was added. The average particle size of the rice husks was 400 μm.

For the comparative examples, examples and test examples thus obtained, the maximum coefficient of static friction and the tensile strength were measured. The maximum static friction coefficient was measured by placing a foam (sample) on a wet iron plate and placing 80 kgf on the foam.
When the weight was placed and the weight was pulled and moved, it was determined from the initial peak value indicated by the load cell. Further, the same sample was measured five times, and the average value was defined as the maximum static friction coefficient.

The above measured values are shown in Tables 2 (a), (b),
(C) and Tables 3 (a) and 3 (b).

[0019]

[Table 2]

[0020]

[Table 3]

In addition, when the size of the cell 10 with the chaff and the cell 10 without the chaff in FIG. 1B was measured, the cell 10 without chaff was about 35 μm.
The cell in a part of the rice husk was about 550 μm. From this result, the cell 10 is enlarged by the rice husk, and the cell wall 11
It can be seen that the spike effect due to is increased.

[0022]

As described above, according to the present invention,
Wet grip properties (anti-slip properties) are improved by the spike effect of the seed shell. Further, since the present invention is applied to the foam for shoe soles, there is no possibility that the lightness of shoes or the like is impaired.
In particular, since the present invention is applied to a foam for soles, a conventional case applied to solid rubber (Japanese Unexamined Patent Publication No. 5-154005)
No. 6-100732), the seed shell has the effect of enlarging the cell (cavity) of the foam, and therefore the spike effect by the cell wall is improved, and water easily escapes into the large cell. The wet grip property is improved. In addition, since the effect of improving the wet grip property by these cells and cell walls can be obtained even after the seed husk slides down, stable slip resistance can be obtained.

In particular, when the addition amount is 0.05 to 0.5 parts by weight, an anti-slip effect can be obtained with an extremely small amount of seed hulls.
There is an excellent effect that the tensile strength hardly decreases.

[0024]

[The background of the application] The present application is an application claiming so-called domestic priority .

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a foam according to an embodiment of the present invention, for explaining the principle of the present invention.

FIG. 2 is an enlarged sectional view of a conventional foam.

[Explanation of symbols]

 13: Seed shell

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C08J 9/04 CEQ C08J 9/04 CEQ // B32B 9/02 B32B 9/02 (58) Fields surveyed (Int.Cl. ⁷ A43B 13/04 A43B 13/22 B32B 5/16 B32B 5/18 C08J 9/04 CEQ B32B 9/02

Claims (3)

(57) [Claims] 1. A foam for rubber soles and / or resins for shoe soles , wherein a crushed material obtained by crushing a seed shell to an average particle diameter of 1.0 mm or less is blended, and the amount of the crushed material added is: Raw rubber and / or resin 1
Set from 0.05 to 2.0 parts by weight based on 00 parts by weight
Foam for shoe soles. 2. The foam for a shoe sole according to claim 1 , wherein the seed shell is a walnut shell or a shell of a gramineous shell. 3. The foam for a shoe sole according to claim 1 , wherein the average particle diameter is 10 μm to 600 μm.