JP4060957B2 - Shoe sole material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shoe sole material, and more particularly to an outer sole (a ground contact sole).
[0002]
[Prior art]
In addition to cushioning properties, grip properties, and wear resistance, shoe sole materials that constitute the outer soles of shoes such as sports shoes are required to be lightweight. From the viewpoint of such light weight, a shoe sole material made of a foam is superior to a non-foam.
[0003]
[Problems to be solved by the invention]
However, the foam is inferior in strength, particularly wear resistance, compared to the non-foam.
Accordingly, an object of the present invention is to improve the lightness and wear resistance of a shoe sole made of foam.
[0004]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a shoe sole material comprising a resin and / or rubber foam-cured and constituting a grounded bottom, wherein 10 to 50 carbon blacks per 100 parts by weight of polymer. is added parts by weight, an average particle diameter of the carbon black is set to 11～30Nm, relative to the total polymer, cis-1,4-polybutadiene is 60 to 80 wt% Bed trend, and styrene-based resin (hereinafter, "styrene Resin) and / or syndiotactic 1,2 polybudadiene is blended in a total amount of 5 to 25% by weight.
[0005]
First, in the present invention, BR (cis 1,4 polybutadiene) is used as the main polymer in order to improve the wear resistance .
[0006]
In general, by adding carbon black, the wear resistance of the shoe sole material is improved. However, usually, when carbon black is added to the diene rubber used for the shoe sole material, the interaction between the polymer and the carbon black is strong and the foaming property is lowered, so that the weight of the shoe sole material cannot be reduced. Therefore, in the present invention, in order to improve the foaming processability, the foamability is improved by adding styrene resin and / or RB (syndiotactic 1,2 polybudadiene). These resins have higher fluidity at higher temperatures than rubber, that is, their viscosity decreases, so that foamability is improved and sufficient weight reduction can be achieved.
[0007]
The blend ratio of styrene resin and / or RB is set to 5% by weight or more of the total polymer. This is because the foamability cannot be sufficiently improved when the blend ratio of these resins is less than 5% by weight.
[0008]
On the other hand, the blend ratio of these resins is set to 25% by weight or less of the total polymer. This is because when the blend ratio of these resins is 25% by weight or more, the hardness of the foam becomes too high, and functions such as cushioning and gripping properties are deteriorated.
[0009]
In the present invention, the blend ratio of the resin is preferably set to 10 to 20% by weight. As the resin, styrene resin is more versatile and easily available than RB.
[0010]
The reason why the amount of carbon black added is 50 parts by weight or less is that when the amount added exceeds 50 parts by weight, the foaming properties are reduced and the specific gravity of the material itself is increased, and the weight cannot be reduced sufficiently. is there.
On the other hand, the reason why the amount of carbon black added is 10 parts by weight or more is that if the amount added is less than 10 parts by weight, the wear resistance is not sufficiently improved.
The amount of carbon black added is preferably 10 to 35 parts by weight with respect to 100 parts by weight of the polymer.
[0011]
The reason why the average particle size of carbon black is 11 to 30 nm is that carbon black having this particle size exhibits high wear resistance and at the same time has a small degree of reduction in foaming.
[0012]
In the present invention, in addition to the main polymer (BR) and the resin, diene rubbers such as IR and NBR, synthetic rubbers such as EPDM and EPM, EVA (ethylene-vinyl acetate copolymer), etc. These resins may be properly blended (blended).
[0013]
【Example】
Examples of the present invention will be described below in order to clarify the effects of the present invention.
Examples 1-5
A foam was obtained by adding carbon black in the rubber composition of FIG. The additive is shown in FIG.
Comparative Examples 1-8
A foam was obtained by adding carbon black in the rubber composition of FIG. In addition, the mixing | blending of the additive was set the same as the Example.
[0014]
The load was set to 26.5 N, and the worn volume per 1,000 revolutions was measured according to the Akron abrasion test method (JISK6264). The volume ratio is shown in FIG.
[0015]
From Comparative Examples 1 and 2, it can be seen that the wear resistance decreases when the amount of carbon black added is small.
In addition, it can be seen from Comparative Examples 4 and 5 that if the particle size of the carbon black to be added is too large, the wear resistance is significantly reduced.
[0016]
From Comparative Example 3, it can be seen that if the blend ratio of BR as the main polymer is too small, the wear resistance is reduced.
[0017]
On the other hand, it can be seen that the shoe sole materials of Examples 1 to 5 are lightweight and have excellent wear resistance.
In each of Examples 1 to 5, the high styrene resin is blended, but the same result can be obtained by blending only RB without blending the high styrene resin. This is because RB is also excellent in foamability like high styrene resin, and has good affinity with BR as the main polymer.
[0018]
In Comparative Example 6 in which no high styrene resin and RB were blended, the fluidity of the press dough deteriorated and foaming became non-uniform.
Further, in Comparative Example 7 in which high styrene resin and RB were added in a total amount of 40% by weight or more based on the entire polymer, the hardness was too high (SRIS-C hardness was 82 °), and the cushioning property and gripping property were lowered. I found out that
Further, it was found that in Comparative Example 8 in which 60% by weight of carbon black having a particle size of 11 to 30 nm was added, the foamability was remarkably reduced, and the specific gravity was remarkably increased.
[0019]
【The invention's effect】
As described above, according to the present invention, since an appropriate amount of styrene resin and / or RB is added to the whole polymer, even if carbon black having a small particle diameter is added, the fluidity of the material during pressing is high. In other words, since the viscosity is lowered, foamability is improved, uniform foaming occurs, and foaming is sufficiently performed, so that the weight of the shoe sole material can be reduced. Further, since carbon black having a small particle diameter can be added, the abrasion resistance of the foam is improved.
[Brief description of the drawings]
FIG. 1 is a chart showing a polymer blend ratio, an amount of carbon black added, and the like according to an embodiment of the present invention.
FIG. 2 is a chart showing the amount of additive added according to the embodiment.

Claims (2)

A shoe sole material formed by foaming and curing resin and / or rubber and constituting a grounding bottom,
10 to 50 parts by weight of carbon black is added to 100 parts by weight of the polymer, and the average particle size of the carbon black is set to 11 to 30 nm.
Cis-1,4-polybutadiene is 60 to 80 wt% Bed trend with respect to the total polymer, and styrene-based resins and / or syndiotactic 1,2 poly butadiene is 5-25 wt% blend with respect to the total polymer in total Sole material characterized by In claim 1,
Shoe sole with specific gravity set to 0.5-0.8.

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