JP2005118243A - Shoe sole and shoe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shoe sole that is light and has a good wet gripping nature and durability as well as a shoe that is provided with this feature. <P>SOLUTION: This shoe sole 3 is made of non-porous cross-linking rubber and contains 30 masses section or over and 70 masses section or less of acrylonitrile-butadiene in 100 masses section of the substrate surface rubber, 30 masses section or over and 70 masses section or less of rubber conjugated with high cis polybutadiene and high-crystalline syndiotactic polybutadiene, 15 masses section or over and 35 masses section or less of carbon black of 10nm or over and 25nm or less in particle diameter in 100 masses section of the substrate surface, with no softener contained or with 3 masses section or less when contained. The shaped article of which the specific density is 1.00 or over and 1.10 or less composes 60% or more of the volume. A shoe 1 that is provided with such a shoe sole 3 is light, comfortable, and has a good wet gripping nature and durability. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shoe sole made of a rubber molded body such as golf shoes, tennis shoes, jogging shoes, trekking shoes, and men's shoes. Moreover, it is related with the shoes provided with this shoe sole.

  Many shoe soles made of a shoe sole, upper, insole and the like are made of rubber. The shoe sole is a part that receives the weight of the wearer. The shoe sole is required to have high strength because an impact load accompanying the exercise is applied. In order to increase the strength, fillers such as carbon black and silica are blended with the base rubber in the shoe sole. These fillers generally have a higher specific gravity than the base rubber. In the shoe sole, a filler is usually used in an amount of 50 parts by mass or more. Generally, HAF carbon black (particle diameter of 26 nm to 30 nm) or the like is mainly used. Incidentally, the specific gravity of carbon black is around 1.8. The combination of these fillers makes the shoe soles heavy. Shoes with heavy soles are heavier. If the shoes are heavy, the wearer feels uncomfortable and the legs tend to get tired. Therefore, weight reduction of shoes is required.

  In order to reduce the weight of a shoe sole, there is a porous shoe sole that includes air bubbles (for example, Japanese Patent Application Laid-Open No. 2-149206). These bubbles are obtained by blending a foaming agent and minute hollow spheres (also called microballoons) with the rubber substrate. However, the bubbles tend to impair the strength and wear resistance of the shoe sole. The shoe sole rubs directly against the ground. The low wear resistance of the sole is a serious drawback for the shoe. In addition, a softener such as oil is often added to the shoe sole for the purpose of improving processability and flexibility. The blending of this softening agent may also help to reduce the strength and wear resistance of the shoe sole.

From the structural aspect, there is a method in which the shoe sole is thinned for weight reduction. However, the durability of the shoe sole is also reduced by thinning the shoe sole. It may be difficult to reduce the thickness due to processing and design requirements. Attempts have been made in which the shoe sole is formed as a molded body containing no bubbles, and the specific gravity of the rubber composition used is kept small. In the rubber composition, a filler having a high reinforcing property is used, and the amount of the filler having a high specific gravity is suppressed to a small amount. This rubber composition is described in, for example, JP-A-2001-211905. As a result, the weight is reduced and the durability is also maintained. However, this shoe sole does not have sufficient wet grip performance. In addition, when the amount of carbon black can be suppressed, the shoe sole becomes soft and wear resistance tends to be inferior.
JP-A-2-149206 JP 2001-211905 A

  Recently, sports shoes and the like have been required to be lightweight and have good wet grip properties. This invention is made | formed in view of such the present condition, and it aims at provision of the shoes provided with the shoe sole which is excellent in wet grip property and durability, and such performance, while being lightweight.

In the shoe sole according to the present invention, a molded body that satisfies the following conditions occupies a volume of 60% or more.
(1) It consists of a non-porous crosslinked rubber,
(2) In 100 parts by mass of the base rubber, acrylonitrile-butadiene rubber is contained in an amount of 30 parts by mass or more and 70 parts by mass or less,
(3) 30 to 70 parts by mass of rubber in which high cis polybutadiene and highly crystalline syndiotactic polybutadiene are combined are included,
(4) Carbon black having a particle size of 10 nm to 25 nm is contained in an amount of 15 parts by mass to 35 parts by mass with respect to 100 parts by mass of the base rubber.
(5) The amount when the softener is not included or is included is 3 parts by mass or less,
(6) Specific gravity is 1.00 or more and 1.10 or less.

  Preferably, 20 parts by mass or more and 40 parts by mass or less of high styrene resin or syndiotactic 1,2-polybutadiene is included with respect to 100 parts by mass of the base rubber of the molded body.

  Further, the shoe sole includes 40 parts by mass or more and 65 parts by mass or less of the acrylonitrile-butadiene rubber, and 35 parts by mass or more and 60 parts by mass of a rubber in which high cis polybutadiene and high crystalline syndiotactic polybutadiene are combined. More preferably, it is contained below.

  Furthermore, it is preferable that the syndiotactic polybutadiene crystal is contained in an amount of 10% by mass or more and 20% by mass or less in the rubber compounded as a rubber in which the high cis polybutadiene and the highly crystalline syndiotactic polybutadiene are combined.

  This shoe sole is lightweight and excellent in wet grip. Moreover, it has high strength and excellent durability. Moreover, the shoe provided with this sole is lightweight and comfortable to wear. Therefore, the wearer is less tired when this shoe is used. In addition, this shoe is lightweight, comfortable to wear, has excellent wet grip properties and durability, and lasts a long time.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a front view showing a shoe 1 according to an embodiment of the present invention. The shoe 1 includes a shoe sole 3 and an upper 5. The shoe sole 3 is formed by crosslinking a rubber composition. The shoe 1 is configured by attaching an upper 5 and an insole (not shown) to the shoe sole 3. The shoe sole 3 is made of a non-porous molded body in which a rubber composition is crosslinked. The term “porous” refers to a material containing a large number of hollow holes intended by foaming with a foaming agent or blending of minute hollow spheres. Since the shoe sole 3 is non-porous, even if the shoe sole 3 rubs against the ground, it does not easily wear.

  The base rubber of the rubber composition used for the shoe sole 3 includes 30 parts by mass or more and 70 parts by mass or less of acrylonitrile-butadiene rubber (hereinafter referred to as “NBR”). In addition, the base rubber includes a rubber (hereinafter referred to as “VCR”) in which a high cis polybutadiene and a high crystalline syndiotactic polybutadiene are compounded in an amount of 30 to 70 parts by mass. The base rubber can contain a rubber other than the NBR and VCR up to a maximum of 40 parts by mass. As rubbers other than NBR and VCR generally used for shoe soles, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), chloroprene rubber ( CR), ethylene-propylene-diene rubber (EPDM), acrylic rubber (ACM), urethane rubber (U) and the like.

  This NBR is superior in wet grip properties to the other rubbers described above. However, since NBR has a higher specific gravity than other rubbers, the shoe sole tends to be heavy. For this reason, in the rubber composition for shoe soles, it is necessary to balance this characteristic. When the NBR is less than 30 parts by mass, the wet grip property is not sufficient. In this respect, the amount of NBR in the base rubber is more preferably 40 parts by mass or more. More preferably, it is 45 parts by mass or more. When the amount of NBR exceeds 70 parts by mass, the shoe sole becomes heavy. In this respect, the amount of NBR is more preferably equal to or less than 65 parts by mass. More preferably, it is 60 mass parts or less. Among NBR, those having an amount of bound acrylonitrile in NBR of 25% or more and 43% or less are preferable in terms of excellent wet grip properties. More preferably, NBR has a bound acrylonitrile amount in NBR of 31% or more and 36% or less.

  The VCR is a kind of polymer alloy, and the high cis-butadiene rubber in the VCR contains 95% or more of cis 1,4 bonds. More preferably, this polybutadiene contains about 98% of cis 1,4 bonds. In this case, components other than the cis 1,4 bond have a trans content and a vinyl content of about 1% each. Syndiotactic polybutadiene is a chain polymer with a head-to-tail structure, and has a stereoregular structure in which vinyl groups are alternately reversed around the main chain in the structural unit carbon main chain. In the VCR, the syndiotactic polybutadiene (SPB) crystal content in the VCR is more preferably 10% by mass or more and 20% by mass or less from the viewpoint that it is suitable for reinforcing the strength of the shoe sole. More preferably, the SPB crystal content is 12% by mass or more and 18% by mass or less. Furthermore, the SPB crystal content is 15% by mass or more and 18% by mass or less.

  This VCR has a greater effect of increasing strength than other general rubbers. When blended with NBR, a lightweight shoe sole 3 with good wet grip and high strength is obtained. When the amount of VCR is less than 30 parts by mass, the specific gravity increases. Moreover, the hardness of a shoe sole is insufficient, wear resistance is inferior, and durability is lowered. From this viewpoint, the blending amount of the VCR is more preferably 35 parts by mass or more. More preferably, the amount is 40 parts by mass or more. Moreover, when the compounding quantity of VCR exceeds 70 mass parts, wet grip property will not become enough. From this viewpoint, the blending amount of the VCR is more preferably 60 parts by mass or less. More preferably, the amount of VCR is 55 parts by mass or less.

  If an inorganic filler such as normal carbon black or silica is used, the specific gravity of the shoe sole increases. In order to impart appropriate hardness to the shoe sole 3 without increasing the specific gravity, it is preferable to use a resin filler. The resin filler also increases the strength of the shoe sole 3. Examples of the resin filler include high styrene resin or syndiotactic 1,2-polybutadiene. As for the compounding quantity of this resin filler, 20 to 40 mass parts is more preferable. If the amount is less than 20 parts by mass, the hardness tends to be insufficient. From this viewpoint, the compounding amount of the resin filler is more preferably 25 parts by mass or more with respect to 100 parts by mass of the base rubber. More preferably, it is 30 parts by mass or more. Moreover, when the compounding quantity of a resin filler exceeds 40 mass parts, abrasion resistance will fall easily. In this respect, the amount of the resin filler is more preferably 35 parts by mass or less. The high styrene resin is a styrene-butadiene copolymer having a styrene resin content of 60% by mass or more. The syndiotactic 1,2-polybutadiene is a resin that contains 90% or more of 1,2-bond vinyl component in the microstructure and the remaining component is cis 1,4-bond or trans 1,4-bond.

  This rubber composition is blended with carbon black having a particle diameter of 10 nm or more and 25 nm or less so that the specific gravity is kept small and the strength is maintained. The compounding amount of the carbon black is 15 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the base rubber. Since this carbon black has a small particle diameter, it has high reinforcing properties. Therefore, the strength of the shoe sole is maintained even when the amount of carbon black is small. The smaller the particle size is, the higher the reinforcing property is. However, it is not preferable that the particle size is too small from the viewpoint of cost and kneading workability.

  Examples of the carbon black to be used include SAF (Super Ablation Fuenace) having a particle diameter of 11 nm to 19 nm, ISAF (Intermediate Super Abrasion Fuenace) having a particle diameter of 20 nm to 25 nm, and the like. In addition, the value of a particle diameter is measured based on "ASTM D1765". Other fillers such as silica, calcium carbonate, carbon black having a particle diameter exceeding 25 nm, and the like may be used in combination with the above-described carbon black as long as the specific gravity is not excessively increased.

  In this rubber composition, a softener is not blended, or when blended, it is 3 parts by mass or less. Since the blending amount of the softening agent is thus suppressed, the strength of the shoe sole 3 is maintained even when the amount of carbon black as the reinforcing filler is small as described above. Conversely, softeners are used for imparting flexibility, improving processability, etc., but since the amount of filler is small, flexibility is maintained even with a small amount of softener and workability is good. When blended, examples of the softener used include oils such as paraffin oil, naphthene oil, and aromatic oil, and plasticizers such as dioctyl phthalate, dibutyl phthalate, dioctyl sebacate, and dioctyl adipate.

  There is no restriction | limiting in particular in the bridge | crosslinking form of the shoe sole 3, Sulfur bridge | crosslinking, peroxide bridge | crosslinking, etc. are applied. From the viewpoint of physical properties such as cost and strength, sulfur crosslinking is preferred. Further, the shoe sole 3 may be appropriately mixed with a vulcanization accelerator, a crosslinking aid, a silylating agent, a silane coupling agent, an anti-aging agent, a coloring agent, and the like.

  In the shoe sole 3, a molded body having a specific gravity of 1.00 or more and 1.10 or less occupies a volume of 60% or more. When this molded body does not form the entire shoe sole, other molded bodies can be used, for example, at the toe portion of the shoe sole. If the volume of the molded product having the specific gravity of 1.00 or more and 1.10 or less is less than 60%, weight reduction of the shoe sole 3 is not achieved. Preferably, this compact is 80% or more. More preferably, the entire volume of the shoe sole is made of the molded body. The shoe sole 3 has a small specific gravity and a light weight, has excellent wet grip properties and good wear resistance. The shoe 1 having the shoe sole 3 is comfortable to wear and has little fatigue even when worn for a long time. Even if this shoe 1 is used in a wet place, it is difficult to slip. Furthermore, this shoe has less wear and lasts longer. Although the sole 3 is a single layer, the shoe 1 may include a sole 3 including a midsole and an outsole, for example. In this case, the outsole is the shoe sole 3 of the present invention.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Example 1]
50 parts by mass of acrylonitrile-butadiene rubber (“Nipol DN200” manufactured by Nippon Zeon Co., Ltd .; bound acrylonitrile amount: 33.5%), 50 parts by mass of VCR (“VCR617” manufactured by Ube Industries, Ltd .: syndiotactic polybutadiene crystal amount: 17.0%) , 30 parts by mass of high styrene resin (“AMERIPOL 1904” manufactured by Americol Synpol Company), 30 parts by mass of carbon black SAF (“Dia Black A” manufactured by Mitsubishi Kasei Co., Ltd.), anti-aging agent N (“Sannok N of Ouchi Shinsei Chemical Co., Ltd.) "Wax" 1 part by mass, anti-aging agent 200 ("Nocrack 200" from Ouchi Shinsei Kagaku Kogyo Co., Ltd.); 2 parts by mass of 2,6-di-tert-butyl-4-methylphenol, Zinc Hana (Mitsui Metal Industries, Ltd.) 2 parts by weight of stearic acid (Nippon Yushi Co., Ltd.) 1 part by mass, sulfur (“powder sulfur” from Tsurumi Chemical Co., Ltd.), 1 part by mass of vulcanization accelerator DM (“Noxeller DM” from Ouchi Shinsei Chemical; benzothiazyl disulfide), vulcanization accelerator TET ( "Noxeller TET" of Ouchi Shinsei Chemical Co., Ltd .: 0.7 parts by mass of tetraethylthiuram disulfide, 0.1 parts by mass of vulcanization accelerator DT ("Noxeller DT" of Ouchi Shinsei Chemical; di-o-tolylguanidine) And vulcanization accelerator NS (“Noxeller NS” of Ouchi Shinsei Chemical Co., Ltd .; N-tert-butyl-2-benzothiazolylsulfenamide) 0.5 parts by mass in a closed kneader to produce a rubber composition A product was made. The rubber composition was put into a mold and pressurized and heated at 160 ° C. for 10 minutes to obtain a shoe sole.

[Comparative Example 1]
As the base rubber, 80 parts by mass of acrylonitrile-butadiene rubber (“Nipol DN315” from Nippon Zeon Co., Ltd .; bound acrylonitrile amount 26.0%) and 20 parts by mass of styrene butadiene rubber (“SBR1502” from JSR) were used. A shoe sole was obtained in the same manner as in Example 1 except that 10 parts by mass of styrene resin (AMERIPOL 1904) and 35 parts by mass of carbon black SAF (Diablack A) were used.

[Comparative Example 2]
As the base rubber, 70 parts by mass of acrylonitrile-butadiene rubber (the above-mentioned “Nipol DN200”) and 30 parts by mass of the VCR (the above-mentioned “VCR617”) are used. Black A ") A shoe sole was obtained in the same manner as in Example 1 except for 40 parts by mass.

[Comparative Example 3]
A shoe sole was obtained in the same manner as in Example 1 except that 2 parts by mass of a microballoon (“Expancel DU80” manufactured by Nippon Philite Co., Ltd.) was added.

[Example 2]
The shoe sole was the same as in Example 1 except that 25 parts by mass of carbon black SAF (the above-mentioned “Diablack A”) and 5 parts by mass of silica (Degussa “Ultrasil VN3”) were used as fillers. Got.

[Example 3]
Other than using 65 parts by mass of acrylonitrile-butadiene rubber (the above-mentioned “Nipol DN200”) and 35 parts by mass of VCR (“VCR412” of Ube Industries, Ltd .: syndiotactic polybutadiene crystal amount 12.0%) as the base rubber In the same manner as in Example 1, a shoe sole was obtained.

[Example 4]
Other than using 60 parts by mass of acrylonitrile-butadiene rubber (previously “Nipol DN200”), 30 parts by mass of VCR (previously “VCR617”) and 10 parts by mass of styrene butadiene rubber (previously “SBR1502”) as the base rubber Obtained the sole in the same manner as in Example 1.

[Comparative Example 4]
A shoe sole was obtained in the same manner as in Example 1 except that 10 parts by mass of carbon black SAF (the above-mentioned “Dia Black A”) was used.

[Comparative Example 5]
Except that high-styrene resin was not used, carbon black SAF (the above-mentioned “Dia Black A”) was 20 parts by mass, and process oil (“Diana Process Oil PW380” from Idemitsu Kosan Co., Ltd.) was used at 5 parts by mass. A shoe sole was obtained in the same manner as in 1.

[Example 5]
A shoe sole was obtained in the same manner as in Example 1 except that 35 parts by mass of syndiotactic polybutadiene (“RB830” manufactured by JSR) was used instead of the high styrene resin.

[Example 6]
35 parts by mass of high styrene resin (previously “AMERIPOL 1904”), 35 parts by mass of carbon black SAF (previously “Diablack A”), and process oil (previously “Diana Process Oil PW380”) 2 A shoe sole was obtained in the same manner as in Example 1 except that the mass part was used.

[Comparative Example 6]
A shoe sole was obtained in the same manner as in Example 1 except that 30 parts by mass of carbon black HAF (“Dia Black H” manufactured by Mitsubishi Kasei Co., Ltd.) was used instead of carbon black SAF without using high styrene resin.

[Example 7]
A shoe sole was obtained in the same manner as in Example 1 except that 40 parts by mass of acrylonitrile-butadiene rubber (previously described “Nipol DN315”) and 60 parts by mass of VCR (previously “VCR617”) were used as the base rubber. .

[Example 8]
As a base rubber, 30 parts by mass of acrylonitrile-butadiene rubber (the above-mentioned “Nipol DN200”) and 70 parts by mass of a VCR (the above-mentioned “VCR617”) are used. A shoe sole was obtained in the same manner as in Example 1 except that the black A ") was 35 parts by mass.

[Comparative Example 7]
A shoe sole was obtained in the same manner as in Example 1 except that 20 parts by mass of acrylonitrile-butadiene rubber (previously described "Nipol DN315") and 80 parts by mass of VCR (previously described "VCR617") were used as the base rubber. .

[Evaluation]
In Table 1, Table 2, and Table 3, each evaluation method is as follows.
(A) Specific gravity: Measured by “Archimedes” manufactured by Chy Balance Co., Ltd., using a block-shaped test piece cut out from a shoe sole.
(B) Wet grip: An upper was attached to each shoe sole to produce a shoe. Each of these shoes was worn by 10 testers, and the quality of the wet grip property was evaluated on a 5-point scale. The average score of the wearer was taken. Those with a score of 3 or more are preferred.
(C) Hardness: A rubber composition used for a shoe sole was put into a mold and pressed and heated at 160 ° C. for 15 minutes to obtain a plate-like molded body having a thickness of 12 mm. This compact was measured with a Shore A hardness meter according to JIA-K-6253.
(D) Tensile strength: A rubber composition used for a shoe sole was put into a mold and pressed and heated at 160 ° C. for 10 minutes to obtain a plate-like molded body having a thickness of 2 mm. This was punched out as a test piece of JIS-Dumbell No. 3, and a tensile test was performed in accordance with the provisions of JIS-K-6251.
(D) Abrasion amount: A rubber composition used for a shoe sole was put into a mold, and pressed and heated at 160 ° C. for 15 minutes to obtain a disc-shaped test piece having a thickness of 12.7 mm. Using this test piece, the wear capacity of the Akron wear test was measured according to JIS-K-6264. However, in JIS-K-6264, it was supposed to be measured at 1000 revolutions, but this time, the wear capacity was measured at 2000 revolutions.

  As shown in Tables 1 to 3, Comparative Example 1 and Comparative Example 2 have a high specific gravity of shoe soles, Comparative Examples 3 to 5 have poor tensile strength and wear, and Comparative Example 6 has strength and comparison. In Example 7, wet grip property is inferior. On the other hand, in the shoe sole of an Example, evaluation is high compared with the shoe sole of a comparative example. From this evaluation result, the superiority of the present invention is clear.

  The present invention is applied to a shoe sole made of a rubber molded body. Further, the present invention can be applied to sports shoes and men's shoes.

FIG. 1 is a front view showing a shoe according to an embodiment of the present invention.

Explanation of symbols

1 ... shoes 3 ... sole 5 ... upper

Claims (5)

Made of non-porous crosslinked rubber,
30 parts by mass or more and 70 parts by mass or less of acrylonitrile-butadiene rubber is contained in 100 parts by mass of the base rubber, and 30 parts by mass or more and 70 parts by mass of rubber in which high cis polybutadiene and highly crystalline syndiotactic polybutadiene are combined. Part or less,
Carbon black having a particle size of 10 nm to 25 nm is contained in an amount of 15 parts by mass to 35 parts by mass with respect to 100 parts by mass of the base rubber.
The amount when the softener is not included or is included is 3 parts by mass or less,
A shoe sole in which a molded body having a specific gravity of 1.00 or more and 1.10 or less occupies a volume of 60% or more.   The shoe sole according to claim 1, wherein a high styrene resin or syndiotactic 1,2-polybutadiene is contained in an amount of 20 to 40 parts by mass with respect to 100 parts by mass of the base rubber of the molded body.   The acrylonitrile-butadiene rubber is contained in an amount of 40 parts by mass or more and 65 parts by mass or less, and a rubber obtained by combining a high cis polybutadiene and a highly crystalline syndiotactic polybutadiene is contained in an amount of 35 parts by mass or more and 60 parts by mass or less. The shoe sole according to 2.   4. The rubber according to claim 1, wherein the syndiotactic polybutadiene crystal is contained in an amount of 10% by mass or more and 20% by mass or less in the rubber compounded as a composite rubber of the high cis polybutadiene and the highly crystalline syndiotactic polybutadiene. The shoe sole described in Crab. Made of non-porous crosslinked rubber,
30 parts by mass or more and 70 parts by mass or less of acrylonitrile-butadiene rubber is contained in 100 parts by mass of the base rubber, and 30 parts by mass or more and 70 parts by mass of rubber in which high cis polybutadiene and highly crystalline syndiotactic polybutadiene are combined. Part or less,
Carbon black having a particle size of 10 nm to 25 nm is contained in an amount of 15 parts by mass to 35 parts by mass with respect to 100 parts by mass of the base rubber.
The amount when the softener is not included or is included is 3 parts by mass or less,
A shoe having a shoe sole in which a molded body having a specific gravity of 1.00 or more and 1.10 or less occupies a volume of 60% or more.

Images