JP2003024104A - Outsole and shoe having it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outsole 1 having sufficient wet grip characteristics and capable of inhibiting creaking. SOLUTION: The outsole 1 is molded by a rubber composition containing an acrylonitrile-butadiene copolymer of at least 80 mass% in a base polymer. The outsole 1 has a plurality of projected parts 2 on a bottom face. A groove part 3 is formed between adjacent projected parts 2 and 2. A minute unevenness is formed on a lower face of each projected part 2, and projections 4 are formed. The unevenness is formed in a region of 30% or greater of a ground plane. A sectional shape of the projection 4 is generally square. The projections 4 are separated each other. The projections 4 are arranged like a plotting paper. A height of the projection 4 is 0.2-3.0 mm, and a width of the projection 4 is 0.2-3.0 mm. A width of the space between the projections 4 and 4 is 0.2-3.0 mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to shoes such as walking shoes, tennis shoes, golf shoes, jogging shoes, trekking shoes and town shoes, and an outsole used for the shoes.

[0002]

BACKGROUND OF THE INVENTION Shoes have an outsole forming the bottom surface thereof. An important performance requirement for this outsole is that it does not easily slip on the ground, that is, it has good grip. Outsole with good grip prevents the wearer from falling due to slip. Further, a shoe having an outsole with good grip properties also contributes to the ease of exercise for the wearer. Since slippage is likely to occur on wet ground, grip performance (wet grip performance) on wet ground is particularly important.

A general outsole is formed by crosslinking a rubber composition. As the base rubber, styrene-butadiene copolymer, polybutadiene,
Polyisoprene or natural rubber is used. Various studies have been made on the composition of the rubber composition for the purpose of improving the grip property. For example, Japanese Patent No. 2957480 discloses an outsole having improved grip performance by using a specific solution-polymerized styrene-butadiene rubber.

[0004]

There is room for further improvement in the grip of the outsole, and particularly the wet grip is still insufficient. According to the knowledge obtained by the present inventor, the outsole using the acrylonitrile-butadiene copolymer exhibits excellent wet grip properties. However, when a shoe provided with this outsole is used on smooth ground such as marble or tile, the so-called squeak (weep no) is caused by the sliding of the outsole and the ground.
ise) occurs. The squeal causes discomfort to the wearer and others.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an outsole having a sufficient wet grip property and suppressing squeaking.

[0006]

The invention made in order to achieve the above-mentioned object is formed by a rubber composition containing 80% by mass or more of an acrylonitrile-butadiene copolymer in a base polymer. The bottom surface of the ground is finely roughened in an area of 30% or more, and the height of the convex portion is 0.2 mm or more and 3.0 mm or less, and the width of the convex portion is 0.2 mm. The outsole is 3.0 mm or less.

Since this outsole is mainly composed of an acrylonitrile-butadiene copolymer, it has an excellent wet grip property. Singing is suppressed because the contact surface of the outsole is subjected to minute unevenness processing. Suitable protrusions include protrusions and ridges.

Preferably, the gap width of the protrusion is 0.2 mm or more and 3.0 mm or less. In this outsole, squeaking is further suppressed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, with reference to the drawings,
The present invention will be explained in detail based on the preferred embodiments.

FIG. 1 is a bottom view showing an outsole 1 according to one embodiment of the present invention, and FIG. 2 is a side view thereof. A shoe is obtained by attaching an upper or an insole to the outsole 1. The outsole 1 has a plurality of protrusions 2 on the bottom surface. A groove portion 3 is provided between the adjacent protruding portions 2 and 2. Although only the outsole 1 for the right foot is shown in FIG. 1, the outsole for the left foot has a shape obtained by reversing the shape shown in FIG.

FIG. 3 is an enlarged sectional view taken along the line III-III in FIG. As is clear from this figure, the lower surface of the protruding portion 2 is provided with a minute uneven processing. The convex portion subjected to the uneven processing is the protrusion 4. The cross-sectional shape of the protrusion 4 is almost square. The protrusions 4 are separated from each other. As shown in FIG. 1, the protrusions 4 are arranged in a graph paper shape. This protrusion 4
Thereby, the squeal is suppressed even when the acrylonitrile-butadiene copolymer is used. Although the reason why the protrusion 4 suppresses the squeal is not clear in detail, it is presumed that the protrusion 4 is appropriately deformed when the outsole 1 is grounded.

The ratio of the area of the region subjected to the uneven processing to the area of the ground plane (hereinafter, also referred to as "occupancy rate")
Is 30% or more. This reliably suppresses squeaking. From this viewpoint, the occupation ratio is more preferably 35% or more, and particularly preferably 40% or more. The area of the ground contact surface means the area of a region in contact with the ground when a person weighing 60 kg wears shoes on both feet and walks. In the outsole 1 of FIG. 1, all the ground contact surfaces are processed to have irregularities. In other words, the occupation rate of this outsole 1 is 100.
%.

FIG. 4 is a sectional view in which the outsole of FIG. 3 is further enlarged. What is indicated by a double-headed arrow H in FIG. 4 is the height of the protrusion 4. Height H is 0.2 mm
It is set to 3.0 mm or less. When the height H is less than the above range, the protrusions 4 do not deform independently and it is difficult to suppress squeal. From this viewpoint, the height H is more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. If the height H exceeds the above range, buckling of the protrusions 4 may deteriorate the wearing comfort. From this viewpoint, the height H is 2.0 m.
m or less is more preferable, and 1.5 mm or less is particularly preferable.

The width of the protrusion 4 (indicated by a double-headed arrow W1 in FIG. 4) is 0.2 mm or more and 3.0 mm or less. If the width W1 is less than the above range, buckling of the protrusions 4 may deteriorate the wearing comfort. From this viewpoint, the width W1 is more preferably 0.5 mm or more, and particularly preferably 0.8 mm or more. If the width W1 exceeds the above range, the protrusion 4
May not be suppressed because it does not deform. From this viewpoint, the width W1 is more preferably 2.0 mm or less, and is 1.5 mm or less.
mm or less is particularly preferable. When the protrusion has a rectangular cross-sectional shape, the length of the short side is the width W1. When the cross-sectional shape of the protrusion is circular, the diameter is W1.

The gap width between the projections 4 and 4 adjacent to each other (indicated by a double-headed arrow W2 in FIG. 4) is 0.2 mm.
It is preferably at least 3.0 mm. When the width W2 is less than the above range, the protrusions 4 do not deform independently, and it is difficult to suppress squeaking. From this viewpoint, the width W2 is more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. When the width W2 exceeds the above range, the number of the protrusions 4 becomes insufficient and it is difficult to suppress squeal. From this viewpoint, the width W2 is more preferably 2.0 mm or less, and particularly preferably 1.5 mm or less.

The contact area of each protrusion 4 is 0.5 mm.^Two
9 mm or more^TwoThe following are preferred. Ground area is less than the above range
If so, the buckling of the protrusions 4 may deteriorate the wearing comfort.
There is. From this viewpoint, the ground contact area is 0.8 mm^Twothat's all
Is more preferable, 1.0 mm ^TwoThe above is particularly preferable. Contact
If the ground area exceeds the above range, the protrusions 4 will be deformed independently.
It is difficult to suppress squealing. From this viewpoint, the ground contact area is
8 mm^TwoThe following is more preferable, 7 mm^TwoEspecially preferred
Good

The outsole 1 is formed by crosslinking a rubber composition. The base polymer of this rubber composition contains an acrylonitrile-butadiene copolymer (NBR) as a main component. Specifically, the ratio of the acrylonitrile-butadiene copolymer in the total base polymer is 80% by mass or more. By using the acrylonitrile-butadiene copolymer, the outsole 1
The wet grip property of is improved. From this viewpoint, the ratio of the acrylonitrile-butadiene copolymer is 90% by mass.
The above is more preferable, and ideally 100% by mass.

The acrylonitrile-butadiene copolymer promotes the squeal of the outsole 1. However, in this outsole 1, since fine unevenness processing contributes to the suppression of squeal, the squeal hardly occurs. The outsole 1 has both wet grip properties and difficulty in squeaking.

From the viewpoint of wet grip property and workability, an acrylonitrile-butadiene copolymer having an acrylonitrile ratio of 25% or more and 36% or less, particularly 31% or more and 35% or less is preferable.

The rubber that can be used in combination with the acrylonitrile-butadiene copolymer includes styrene-butadiene copolymer, polybutadiene, polyisoprene, polychloroprene, ethylene-propylene-diene copolymer, polyurethane, acrylic rubber, butyl rubber, epichlorohydrin rubber. Examples include polysulfide rubber and natural rubber. A synthetic resin or a thermoplastic elastomer may be used as the base polymer together with the acrylonitrile-butadiene copolymer.

The rubber composition is crosslinked by known means. Usually, sulfur is used as a crosslinking agent. Generally, the compounding amount of sulfur is 0.1 with respect to 100 parts of the base polymer.
3 parts or more and 5.0 parts or less, particularly 0.5 parts or more and 3.0 parts or less. Vulcanization accelerators may be used with the sulfur. Suitable vulcanization accelerators include thiazole vulcanization accelerators, thiuram vulcanization accelerators, sulfenamide vulcanization accelerators, diocarbamate vulcanization accelerators, guanidine vulcanization accelerators and the like. Can be mentioned. In particular, thiazole vulcanization accelerators, thiuram vulcanization accelerators and guanidine vulcanization accelerators are preferable for the outsole 1 of the present invention. The total compounding amount of the vulcanization accelerator is 0.5 with respect to 100 parts of the base polymer.
It is not less than 7 parts and not more than 1.5 parts, especially not less than 4 parts.
As a crosslinking aid, a metal compound such as zinc oxide or a fatty acid such as stearic acid may be blended. As used herein, the term "part" means a mass ratio (parts by weight).

For the purpose of improving the strength, it is preferable to add a filler to the rubber composition. Examples of the filler that can be used include silica, carbon black, calcium carbonate, clay and the like. Among them, silica and carbon black which are excellent in the reinforcing effect are preferable, and silica having a primary particle diameter of 30 nm or less is particularly preferable. Generally, the compounding amount of silica is 3 parts or more and 70 parts or less, and particularly 35 parts or more and 65 parts or less with respect to 100 parts of the base polymer.
An appropriate amount of a silylating agent or a silane coupling agent may be blended with silica, which improves the water repellency of the outsole 1. Further, additives such as a plasticizer, an antioxidant and a colorant may be appropriately blended with the rubber composition.

In the production of this outsole 1, first, a base polymer, a cross-linking agent, various additives and the like are kneaded by, for example, a closed kneader, an open roll or the like to obtain a rubber composition. Next, this rubber composition is put into a mold provided with a cavity having the same shape as the outsole 1. Next, the rubber composition is heated and pressurized to cause a crosslinking reaction. In this way, the outsole 1 is molded. Of course, other molding methods such as injection molding may be used.

FIG. 5 is a bottom view showing an outsole 6 according to another embodiment of the present invention. This outsole 6 also has a protrusion 7 similar to the outsole 1 of FIG. The lower surface of some of the protrusions 7 is subjected to minute unevenness processing. A protrusion 8 similar to that of the outsole 1 of FIG. 1 is formed in the region where the uneven processing is performed. The occupancy of the outsole 6 is 30% or more. Since this outsole 6 contains an acrylonitrile-butadiene copolymer as a main component, it has excellent wet grip properties. In this outsole 6, squeal is suppressed by the uneven processing.

FIG. 6 is a bottom view showing an outsole 9 according to still another embodiment of the present invention. The main component of this outsole 9 is an acrylonitrile-butadiene copolymer. Therefore, the outsole 9 has excellent wet grip properties.

The outsole 9 has protrusions 10 of various shapes. The lower surface of some of the projecting portions 10 is subjected to minute unevenness processing. The ridges 11 are formed in the area where the unevenness is applied.

FIG. 7 is an enlarged sectional view taken along the line VII-VII of FIG. In FIG. 7, what is indicated by a double-headed arrow H is the height of the ridge 11. The height H is set to 0.2 mm or more and 3.0 mm or less. If the height H is less than the above range, the streaks 11 do not deform independently, and it is difficult to suppress squeaking. From this viewpoint, the height H is more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. When the height H exceeds the above range, buckling of the streaks 11 may deteriorate the wearing comfort. From this viewpoint, the height H is 2.0.
mm or less is more preferable, and 1.5 mm or less is particularly preferable.

The width of the ridge 11 (indicated by a double-headed arrow W1 in FIG. 7) is set to 0.2 mm or more and 3.0 mm or less. If the width W1 is less than the above range, buckling of the ridges 11 may deteriorate the wearing comfort. From this viewpoint, the width W1 is more preferably 0.5 mm or more, and 0.8 m
m or more is particularly preferable. When the width W1 exceeds the above range,
The streak 11 may not be deformed and the squeal may not be suppressed.
From this viewpoint, the width W1 is more preferably 2.0 mm or less, and particularly preferably 1.5 mm or less.

The gap width between the adjacent ridges 11 and 11 (indicated by a double-headed arrow W2 in FIG. 7) is 0.2 m.
It is preferably m or more and 3.0 mm or less. If the width W2 is less than the above range, the streaks 11 do not deform independently, and it is difficult to suppress squeal. From this viewpoint, the width W2 is more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. Width W2
Is more than the above range, the number of streaks 11 is small and it is difficult to suppress squeal. From this viewpoint, the width W2 is 2.0 m.
m or less is more preferable, and 1.5 mm or less is particularly preferable.

The occupancy rate is set to 30% or more even in the concave-convex processing having the streaks 11. This reliably suppresses squeaking. From this viewpoint, the occupation ratio is more preferably 35% or more, and particularly preferably 40% or more.

[0031]

The effects of the present invention will be clarified by the following examples, but the present invention should not be construed in a limited way based on the description of the examples.

[Example 1] Acrylonitrile-butadiene copolymer (trade name "Nipol DN2 manufactured by Nippon Zeon Co., Ltd."
00 "), silica (trade name" Ultrasil VN3 "manufactured by Degussa) 45 parts, and bis- (3-triethoxysilylpropyl) tetrasulfene (trade name" Si69 "manufactured by Degussa) as a silane coupling agent. ) 4.0 copies,
Dioctyl phthalate as a plasticizer (trade name "DOP" by Sanken Kako Co., Ltd.) 2.0 parts, 2,6 as an anti-aging agent
-Di-tert-butyl-4-methylphenol (trade name "Nocrac 200" of Ouchi Shinko Chemical Industry Co., Ltd.) 2.0
Parts, other anti-aging agent "Ouchi Shinko Kagaku Kogyo's trade name" SANNOC N ") 0.5 parts, zinc oxide 3.0 parts and stearic acid 1.0 part are kneaded with a Banbury mixer, and a rubber composition Got Next, this rubber composition was charged into an open roll, and 0.5 part of sulfur, 1.3 parts of dibenzothiazyl disulfide as a vulcanization accelerator (trade name "NOXCELLER DM" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), 0.7 parts of tetraethyl thiuram disulfide (trade name "NOXCELLER TET" manufactured by Ouchi Shinko Chemical Co., Ltd.) as another vulcanization accelerator and di-o-tolyl guanidine (Ouchi Shinko Co., Ltd.) as another vulcanization accelerator. 0.1 part of a trade name "NOXCELLER DT" manufactured by Kagaku Kogyo Co., Ltd. was added and kneaded to obtain a rubber composition.

Next, a mold provided with a cavity having the same shape as the outsole was prepared and filled with the rubber composition. And it pressurized and heated at 160 degreeC for 8 minutes, and obtained the outsole of Example 1. The bottom shape of this outsole is as shown in FIG. The occupancy of the outsole is about 40%, the height H of the protrusion is 1.0 mm, the width W1 of the protrusion is 1.0 mm, and the gap width W2 between the protrusions is 1.0 mm.

[Examples 2 and 3 and Comparative Examples 1 and 2]
Examples 2 and 3 and Comparative Examples 1 and 2 were performed in the same manner as in Example 1 except that the height H, width W1 and gap width W2 of the protrusions were changed to those shown in Table 1 below. Got an outsole.

[Comparative Example 3] The occupancy rate was changed to 20 by changing the mold.
An outsole of Comparative Example 3 was obtained in the same manner as in Example 1 except that the percentage was changed to%.

[Comparative Example 4] A comparative example was carried out in the same manner as in Example 1 except that the amount of the acrylonitrile-butadiene copolymer was 70 parts and 30 parts of polybutadiene (trade name "BR11" of JSR Co., Ltd.) was added. The outsole of Example 4 was obtained.

[Wet grip] A shoe was obtained by attaching a known upper and insole to the outsole.
The shoes were worn by 10 testers and walked on a wet concrete ground. Then, the wet grip property was evaluated on a scale of 5 from "1" to "5". The non-slip material was designated as "5" and the slippery material was designated as "1". The average of the evaluation scores of 10 testers is shown in Table 1 below.

[Difficulty in Squeaking] Each of the 10 testers was made to wear the above shoes and walked on a dry marble ground. Then, the difficulty of squeaking was evaluated on a scale of 5 from "1" to "5". The case where no squeaking occurred at all was set to "5", and the one which caused the most squeaking was set to "1".
The average of the evaluation scores of 10 testers is shown in Table 1 below.

[0039]

[Table 1]

As shown in Table 1, the squeal is likely to occur in the outsole of Comparative Example 1 where the unevenness processing is too small and the outsole of Comparative Example 2 where the unevenness processing is too large. In addition, squealing is likely to occur even in an outsole whose occupation rate is too small. Furthermore, the outsole of Comparative Example 4 in which the ratio of the acrylonitrile-butadiene copolymer is low is inferior in wet grip. On the other hand, the outsoles of the respective examples exhibit excellent wet grip properties and, moreover, squeal hardly occurs. From these evaluation results, the superiority of the present invention is clear.

[0041]

As described above, the outsole of the present invention is excellent in both wet grip performance and difficulty in producing squeal. Shoes with this outsole are not slippery and do not cause discomfort to the wearer.

[Brief description of drawings]

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

FIG. 2 is a side view showing the outsole of FIG. 1.

FIG. 3 is an enlarged cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view showing the outsole of FIG. 3 in a further enlarged manner.

FIG. 5 is a bottom view showing an outsole according to another embodiment of the present invention.

FIG. 6 is a bottom view showing an outsole according to still another embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view taken along the line VII-VII of FIG.

[Explanation of symbols]

1, 6, 9 ... Outsole 2, 7, 10 ... Projection 3 ... Groove 4, 8 ... Protrusion 11 ... Muscle

Claims (4)

[Claims] 1. A rubber composition comprising an acrylonitrile-butadiene copolymer in an amount of 80% by mass or more in a base polymer, and the bottom surface of the grounding surface is subjected to fine unevenness treatment in an area of 30% or more of the ground contact surface. And the height of the convex portion of this uneven processing is 0.2 mm or more and 3.0 mm or less,
An outsole in which the width of the convex portion is 0.2 mm or more and 3.0 mm or less. 2. The gap width of the protrusion is 0.2 mm or more.
The outsole according to claim 1, which is 0 mm or less. 3. The convex portion is a protrusion or a ridge.
Alternatively, the outsole according to claim 2. 4. A rubber composition comprising an acrylonitrile-butadiene copolymer in an amount of 80% by mass or more in a base polymer, and the bottom surface of the ground surface is subjected to fine unevenness treatment in an area of 30% or more of the ground contact surface. And the height of the convex portion of this uneven processing is 0.2 mm or more and 3.0 mm or less,
A shoe having an outsole in which the width of the convex portion is 0.2 mm or more and 3.0 mm or less.