JP3100592B2 - Shoe outsole - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shoe outsole, and more particularly to a shoe outsole capable of improving gripping properties, providing excellent anti-slip properties even on a scaffold having a severe unevenness and wetness, and improving safety. It is suitably used as an outsole for trekking shoes.

[0002]

2. Description of the Related Art The anti-slip property of shoes is an important performance for shoes, and a sole, that is, an outsole that is in contact with a scaffold (ground), is formed of a rubber composition to form an adhesive friction characteristic of rubber. Slip resistance is obtained by force.

[0003] However, an outsole made of a rubber molded article can provide generally excellent anti-slip properties when the scaffold is in a dry state, but has a reduced anti-slip property when it is wet on a rainy day or on a waterside. However, there is a danger that the range of exercise may need to be restricted, or in the worst case, a fall may occur. this is,
When the scaffold is wet, a water film is interposed between the outsole surface and the scaffold, and the water film reduces the adhesive friction force between the two.

[0004]

Therefore, in order to prevent slippage even on a wet scaffold, conventionally, a rubber composition made of a material having excellent water absorbency has been used to remove water interposed between the outsole and the scaffold. Attempts have been made to improve the anti-slip properties by absorbing the membrane with an outsole. However, in this proposal, there is a problem that the amount of water to be sucked is limited, and that shoes become heavy due to sucking water, making it difficult to walk (exercise).

Contrary to the use of the above-described material having excellent water absorption, the present applicant discloses in Japanese Patent Application Laid-Open No. 9-322806 that water having a water absorption of 0% or more and 1% or less on a weight basis. The outsole is formed with a rubber composition that is difficult to adhere, and when the outsole comes into contact with a wet scaffold, the water interposed between the outsole and the scaffold is easily discharged around the outsole, making it less slippery I have. However, in the outsole of a shoe that walks on a highly uneven scaffold such as a rocky place such as trekking shoes, even if the water absorption of the rubber constituting the outsole is reduced, satisfactory anti-slip properties are obtained when the scaffold is wet. It is not possible.

[0006] Therefore, in the case of an outsole of a shoe used on a scaffold which has severe irregularities and is wet, it is difficult to prevent the rubber material constituting the outsole from slipping even if the water absorption is controlled. It is necessary to further increase the grip of the sole.

The present invention has been made in view of the above circumstances, and further enhances the grip force of an outsole on a scaffold, and provides a good anti-slip property even on a highly uneven and wet scaffold. The goal is to obtain the character.

[0008]

In order to solve the above-mentioned problems, the present inventor has proposed a relationship between the slip resistance of a shoe outsole and a viscoelastic behavior of an outsole made of a vulcanized rubber molded article in a wet rocky place. Was examined. As a result, as shown in FIG. 5, in the dynamic viscoelastic strain dispersion of the vulcanized rubber at a frequency of 10 Hz, a loss coefficient (tan δ) at a temperature of −10 ° C. at a dynamic strain of 2.0% and a complex elastic modulus (E). ^* ) It was found that the larger the value of), the better the grip of the outsole. In FIG. 5, the complex elastic modulus (E ^* ) and the loss coefficient (tan)
δ) generally shows a correlation, and generally has a loss factor (tan
As δ) increases, the complex modulus (E ^* ) also increases. In general, in the distortion dispersion of dynamic viscoelasticity of rubber, the larger the loss coefficient (tan δ), the larger the hysteresis frictional force of rubber against a contact object at the time of rubber deformation, and the larger the complex elastic modulus (E ^* ). It is known that frictional force due to an edge effect on a contact object of rubber at the time of rubber deformation increases.

On the other hand, when a loss coefficient (tan δ) of the vulcanized rubber depending on temperature was measured, as shown in FIG.
In the temperature range of 100 ° C to 100 ° C, the loss factor (t
anδ) and the glass transition temperature (Tg) of the base rubber constituting the vulcanized rubber were found to match.

Therefore, the present invention is based on the premise that styrene-butadiene rubber having excellent balance of various mechanical properties and excellent abrasion resistance is used as a main component of the base rubber.
Based on the findings obtained above, a styrene butadiene rubber having a glass transition temperature (Tg) as close as possible to −10 ° C. is used as a base rubber and vulcanized to form an outsole. The complex modulus (E ^* ) and the loss coefficient (tan δ) of the outsole at a dynamic strain of 2.0% at a temperature of −10 ° C. are increased, and the grip force of the outsole on a scaffold is dramatically improved. Let me.

That is, the present invention relates to an outsole for a shoe comprising a vulcanized molded article of a rubber composition, wherein the base rubber of the rubber composition comprises styrene-butadiene rubber of 70 to 100.
The styrene-butadiene rubber has a glass transition temperature (Tg) of −33 ° C. or higher and −10 ° C. or lower and a dynamic strain of dynamic viscoelasticity at a frequency of 10 Hz.
The loss factor (tan δ) at a temperature of −10 ° C. at 0% is:
Greater than 0.26, 1.5 or less, and the complex elastic modulus at the same conditions ^{(E *)} is greater than 150 kgf / cm ^2, the shoe outsole, characterized in that it is 750 kgf / cm ² or less Is provided.

Ideally, from the above findings, it is preferable to use a styrene-butadiene rubber having a glass transition temperature (Tg) around -10 ° C., but a styrene-butadiene rubber having such a high glass transition temperature (Tg) is preferably used. Is difficult with current polymerization techniques. Therefore, in the present invention, a styrene-butadiene rubber having a higher glass transition temperature than the styrene-butadiene rubber having the highest glass transition temperature (−34 ° C.) used for the conventional outsole is selected and used. Specifically, for example, NS116 (trade name) manufactured by Zeon Corporation [solution-polymerized styrene-butadiene rubber, glass transition temperature (Tg): −25 ° C.] can be mentioned. Not limited to this specific example, the glass transition temperature (Tg) is −33 within the range where the mechanical properties of the styrene-butadiene rubber are not impaired by adjusting the copolymer composition ratio, the copolymer structure, the molecular weight, and the like of the styrene-butadiene rubber. Above ℃
It is preferable to use one closer to -10 ° C. More preferably, -30 ° C or higher, most preferably -25 ° C.
As described above, it is preferable to use a material having a temperature of −10 ° C. or less.
Incidentally, the glass transition temperature (Tg) of styrene-butadiene rubber used for the outsole of conventional shoes is often in the range of -55 ° C to -45 ° C, and that of styrene-butadiene rubber used for tires and other industrial rubber products is high. It was equivalent.

In the outsole of the present invention, the glass transition temperature (Tg) of the styrene butadiene rubber as the base rubber is not less than −33 ° C. and not more than −10 ° C., and the outsole obtained by vulcanizing the base rubber is used. The temperature-dependent viscoelasticity is the glass transition temperature (Tg) of styrene butadiene rubber, -3.
In a temperature range of 3 ° C. or more and −10 ° C. or less, the loss factor (tan)
δ) shows the peak value. Therefore, the loss coefficient (tan δ) at −10 ° C. of the outsole of the present invention is larger than that of the conventional outsole (vulcanized molded article of styrene butadiene rubber having a glass transition temperature (Tg) of −34 ° C. or less), As a result, the loss coefficient (tan δ) and the complex modulus (E ^* ) at a temperature of −10 ° C. at a dynamic strain of 2.0% are larger than those of the conventional outsole, and the grip on the scaffold is improved. It can be gripped with strong gripping power even on wet rocky areas with severe irregularities, making it hard to slip.

The outsole of the present invention has a frequency of 10 Hz.
The loss coefficient (tan δ) at a temperature of −10 ° C. at a dynamic strain of 2.0% in the dynamic viscoelastic strain dispersion at 0.2% is greater than 0.26, preferably 0.30 or more, and more preferably 0.
Shows 40 or more and has a complex elastic modulus (E ^* ) of 155 k
gf / cm ² , preferably 200 kgf / cm ²
cm ² or more, more preferably 260 kgf / cm ²
The above is shown. That is, the hysteresis frictional force against the scaffold and the frictional force due to the edge effect are larger than those in the related art.

The larger the loss coefficient (tan δ) and the complex elastic modulus (E ^* ), the higher the grip performance. However, if the grip performance is too high, the shoes will not slip at all, causing damage to the ankle and the like. It will be easier. Therefore, the loss coefficient (tan δ) is 1.5 or less, preferably 1.2 or less,
More preferably, it is 1.0 or less. Further, when the complex elastic modulus (E ^* ) is too large, the shock absorption of the outsole tends to decrease. Therefore, the complex elastic modulus (E ^* )
Is 750 kgf / cm ² or less, preferably 600 kgf
f / cm ² or less.

The styrene-butadiene rubber used in the present invention is not limited to oil-extended rubber and non-oil-extended rubber as long as the glass transition temperature (Tg) is from -33 ° C to -10 ° C. However, in consideration of lightness of the outsole of the shoe, environmental pollution, and the like, it is preferable to use a non-oil-extended rubber. This is because oil-extended rubber often has a high degree of blackness due to added oil, which impairs the lightness of outsole of shoes.Additionally, added oil generally has a lot of aroma oil, and aroma oil has a bad influence on the environment. This is because they have been moving in a direction of not using them in recent years.

The styrene-butadiene rubber preferably has a copolymer composition having a bound styrene content of 15 to 25% by weight and a bound vinyl content of 35 to 70% by weight. By using the copolymer composition, the vulcanized rubber composition becomes excellent in tensile strength, wear resistance and stability, and the high grip force of the outsole is maintained for a long time. .

The glass transition temperature (Tg) is -3.
When the whole base rubber is not composed of styrene butadiene rubber having a temperature of 3 ° C. or more and −10 ° C. or less, it is used by mixing with another rubber. Other rubbers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (C
R), butyl rubber (IIR), acrylic rubber (AC
M), urethane rubber and the like. These can be used alone or in combination of two or more.

As the vulcanizing agent for vulcanizing the base rubber, for example, sulfur, organic sulfur-containing compounds, organic peroxides, quinone dioximes and the like are used. These vulcanizing agents are base rubber 10
Generally, 1 to 3 parts by weight, preferably 1.5 parts by weight per 0 parts by weight
It is preferred to use up to 2.5 parts by weight. When a vulcanizing agent for sulfur or an organic sulfur-containing compound is used, a vulcanization accelerator may be used. Examples of the vulcanization accelerator include inorganic accelerators such as slaked lime, magnesia (MgO), and litharge (PbO);
Organic accelerators such as a thiazole vulcanization accelerator, a sulfenamide vulcanization accelerator, a thiuram vulcanization accelerator, and a dithiocarbamate vulcanization accelerator can be used. These vulcanization accelerators are generally used in an amount of 0.1 parts per 100 parts by weight of the base rubber.
It is preferable to use 5 to 4 parts by weight, preferably 1 to 2.5 parts by weight. Further, a vulcanization accelerating aid can be blended, and for example, a metal compound such as zinc white and a fatty acid such as stearic acid, oleic acid and cottonseed fatty acid can be used. These vulcanization accelerators are generally used in an amount of 1 per 100 parts by weight of the base rubber.
５5 parts by weight, preferably 1-3 parts by weight.
Further, an anti-aging agent, a softener (plasticizer) and the like may be appropriately blended.

In order to adjust the viscoelasticity of the vulcanized rubber, impart abrasion resistance, adjust the hardness, etc., a filler such as silica or carbon may be blended, water repellency may be imparted, and viscoelasticity etc. may be adjusted. For this purpose, a silane coupling agent or a silylating agent may be blended.

In the present invention, a vulcanized rubber is formed into an outsole. Usually, a vulcanizing agent and various compounding agents to be compounded as required are kneaded, and the kneaded product is put into a mold for outsole. Vulcanization is performed simultaneously with molding to produce an outsole. Alternatively, vulcanization may be performed at the stage of kneading rubber, a vulcanizing agent, and various compounding agents to be compounded as needed, and the obtained vulcanized rubber may be put into a mold for an outsole and molded. The molding can be performed by any molding method such as injection molding and press molding.

The shape of the outsole is preferably a shape in which a groove is formed in the bottom surface and a plurality of block portions whose leading end surfaces are in contact with the scaffold are defined. Each of the shapes of the plurality of block portions may have various shapes such as a prism shape, a truncated pyramid shape, a cylindrical shape, a truncated cone shape, a shape obtained by combining a plurality of prisms and / or cylinders, and the like, in which the side surface is substantially perpendicular or inclined from the groove bottom surface. Shape. In a general outsole, the portion corresponding to the arch of the bottom is a large recess so as not to contact the scaffold, and the groove and the plurality of blocks are portions supporting the region from the toe to the instep of the bottom and Formed on the part supporting the heel.

The groove depth (height of the block portion) is 2 to 7
mm. In this range, the plurality of block portions are deformed according to the shape of the uneven surface of the scaffold, so that the followability to the uneven surface of the scaffold is improved, and the grip performance is further improved. In addition, the impact applied to the foot can be effectively reduced, and the comfort and resilience during exercise can be improved.

The outsole of the shoe of the present invention is most suitable for trekking shoes used on rocky places and the like, but is frequently used for fishing boots, diving shoes, motorcycle shoes, bath shoes, rain shoes, beach sandals and the like. It is also suitable for an outsole of shoes used on a scaffold that is wet with water. Of course, it can be used for shoes other than these.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Example 1 A kneaded product having the formulation shown in the upper part of Table 1 below was prepared, and each kneaded product was placed in a mold for an outsole and vulcanized and formed at 160 ° C. for 10 minutes.
Outsole of Comparative Examples 1 to 3 and Comparative Examples 1 to 3 were prepared. In addition, the shape of these outsole was made into the shape shown in FIG.1 and FIG.2. That is, the outsole 100 includes a first sole portion 51 that supports the sole of the foot from the toe of the foot, a second sole portion 52 that supports the heel portion of the foot, and an arch that connects the first sole portion 51 and the second sole portion 52. And 53. The first sole portion 51 and the second sole portion 52 have a width 1
A plurality of grooves 1 having a length of 20 mm and a depth of 2.0 mm to 5.5 mm are formed in the vertical, horizontal, and oblique directions, and a plurality of blocks 2 having various shapes are defined. The area of the entire bottom surface of the outsole is 250 mm ² , and a plurality of block portions 2
The area of each tip surface of is within the range of 0.1 to 8 cm ² ,
The total area of the plurality of blocks 2 was 65 cm ² . Note that the arch portion 53 is a concave portion that is not entirely grounded.

[0026]

[Table 1]

* 1: Solution-polymerized styrene-butadiene rubber [glass transition temperature (Tg): -25 ° C., bound styrene amount: 21%, bound vinyl amount: 63%], NS116 (trade name), manufactured by Zeon Corporation * 2 : Emulsion polymerized styrene butadiene rubber [Glass transition temperature (Tg): -55 ° C, bound styrene amount: 23.5%,
Bound vinyl content: 20%], SBR1502 (trade name),
* 3: Butadiene rubber [Glass transition temperature (Tg): -1]
10 ° C.], BR11 (trade name), manufactured by Nippon Synthetic Rubber Co., Ltd. * 4: Silane coupling agent [bis- (3-triethoxysilylpropyl) tetrasulfene] Si69 (trade name), manufactured by Degussa * 5: Process Oil PW380 (trade name), manufactured by Idemitsu Kosan Co., Ltd. * 6: Nocrack 200 (trade name), manufactured by Ouchi Shinko Chemical Industry Co., Ltd. * 7: Noxeller NS (trade name), manufactured by Ouchi Shinko Chemical Industry Co., Ltd. * 8: Solution polymerization Styrene butadiene rubber [glass transition temperature (Tg): -39 ° C, bound styrene amount: 25%, bound vinyl amount: 39.5%], SE9191 (trade name), manufactured by Sumitomo Chemical Co., Ltd.

With respect to the outsole of each of the examples and comparative examples produced above, the loss coefficient (tan δ) at a temperature of −10 ° C. at a dynamic strain of 2.0% and the complex in the dynamic viscoelastic strain dispersion at a frequency of 10 Hz. The elastic modulus (E ^* ) was measured. Further, a grip index as an index of slip resistance was measured. In addition, a trekking shoe was prepared by attaching the outsole to the shoe body, and a monitor test was performed.

The above loss coefficient (tan δ) and complex elastic modulus (E ^* ) were measured using a viscoelastic spectrometer (VA-200 modified type) manufactured by Shimadzu Corporation.

For the grip index, the outsole was cut into a predetermined shape (76 mm × 25 mm × 6 mm), and the frictional resistance of the outsole on a wet rocky place was measured using a portable skid resistance tester shown in FIG. . In this method, the relative frictional resistance is read by swinging down a pendulum with rubber from a predetermined height and reading the height at which the pendulum rubs on the road surface and swings up. In addition,
As shown in Fig. 4, the contact area to the wet rocky area is 12.7c.
m. The evaluation was performed using an index when the frictional resistance of the outsole of Comparative Example 1 was set to 100.

In the monitor test, ten testers actually trekked on a wet rocky place using the trekking shoes of each of the examples and comparative examples, and made the grip performance the most important item, and evaluated the feeling of use by a 5-point method. .

The outsoles of Examples 1, 2, and 3 have a loss factor (tan δ) of 0.40 or more, a complex elastic modulus (E ^* ) of 260 or more, a grip index of 145 or more, and evaluation of feeling of use. The number of points was 4.3 or more, indicating that the rubber composition had excellent anti-slip properties on a wet rocky place and good comfort was obtained.

On the other hand, the outsoles of Comparative Examples 1, 2, and 3 exhibited a loss coefficient (tan δ) of 0.25 or less, a complex elastic modulus (E ^* ) of 152 or less, a grip index of 100 or less, and a feeling of use. Was also 3.0 or less, and it was not possible to have good slip resistance on a wet rocky site.

[0034]

As is apparent from the above description, the outsole of the shoe of the present invention has a glass transition temperature (Tg).
Using a base rubber containing 70 to 100% by weight of styrene butadiene rubber having a temperature of −33 ° C. or higher and −10 ° C. or lower, a loss coefficient (tan δ) at a temperature of −10 ° C. at a dynamic strain of 2.0% and a complex elasticity Since the rate (E ^* ) is larger than before, it is possible to obtain a very high gripping force on the scaffold. As a result, even when the scaffold is used in a wet condition with a highly uneven surface, Good slip resistance can be obtained without slipping due to force. Therefore, for example, it is suitable as an outsole of trekking shoes walking on a rocky place.

[Brief description of the drawings]

FIG. 1 is a bottom view of an outsole according to an embodiment of the present invention.

FIG. 2 is a side view of an outsole according to an embodiment of the present invention.

FIG. 3 is a perspective view of a portable skid resistance tester.

FIG. 4 is a schematic diagram showing measurement conditions when measuring frictional resistance using the portable skid resistance tester of FIG. 3;

FIG. 5 shows a loss coefficient (tan δ) at a temperature of −10 ° C. and a complex elastic modulus (E ^* ) at a dynamic strain of 2.0% of a dynamic viscoelastic strain dispersion at a frequency of 10 Hz of an outsole made of a vulcanized rubber composition ^. FIG. 4 is a diagram showing the relationship between the non-slip property and the non-slip property.

FIG. 6 shows the temperature and loss factor (tan) of the vulcanized rubber composition.
FIG. 6 is a diagram showing the relationship of δ).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Groove 2 Block part 51 1st sole part 52 2nd sole part 53 Arch part 100 Outsole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A43B 13/00-13/42 C08J 3/24 C08J 5/00 C08L 9/06

Claims (2)

(57) [Claims] 1. A outsole of a shoe comprising a vulcanized molded article of a rubber composition, the base rubber of the rubber composition Steel
70 to 100% by weight of lenbutadiene rubber,
Lenbutadiene rubber has a glass transition temperature (Tg) of -3.
3 ° C or higher, -10 ° C or lower, dynamic viscosity at a frequency of 10 Hz
In elastic strain dispersion, the temperature at dynamic strain 2.0%-
The loss factor (tan δ) at 10 ° C. is greater than 0.26
And 1.5 or less, and the complex modulus under the same conditions
(E ^* ) is larger than 150 kgf / cm ² and 750 k
gsf / cm ² or less . 2. The outsole of a shoe according to claim 1, wherein the styrene-butadiene rubber has a bound styrene content of 15 to 25% by weight and a bound vinyl content of 35 to 70% by weight.