JP5568699B1 - Sole for shoes and shoes - Google Patents

Abstract

The shoe sole includes a rubber component including at least one of natural rubber and isoprene rubber, silica mixed with 35 to 60 parts by mass with respect to 100 parts by mass of the rubber component, and a first carbon number of 12 or more. And a secondary alkylamine. Preferably, the primary alkylamine is an amine compound having 12 to 20 carbon atoms, and includes 3 parts by mass or more of the primary alkylamine having 12 to 20 carbon atoms with respect to 100 parts by mass of the rubber component. It is out.
Such a shoe sole has an appropriate hardness and a relatively high strength.

Description

  The present invention relates to a shoe sole having an appropriate hardness as a component of a shoe, and a shoe using the same.

A shoe is manufactured by attaching a shoe sole such as an outer sole or a midsole to an upper covering an instep.
The shoe sole is usually obtained by molding a thermoplastic elastomer. A shoe sole obtained by molding a rubber composition is also known. The rubber composition includes a rubber component, a reinforcing agent, a vulcanization accelerator, and other additives.
Patent Document 1 discloses a primary alkylamine having 8 to 25 carbon atoms as a natural product-derived vulcanization accelerator. Patent Document 1 discloses that the primary alkylamine having 8 to 25 carbon atoms is excellent in vulcanization speed, and that rubber using this vulcanization accelerator can be used for a shoe sole. Yes.

By the way, grip property is mentioned as one of the characteristics required for shoes. In general, it is known that a shoe sole having a lower hardness exhibits a higher grip. However, the lower the hardness of the sole, the lower the strength of the sole and the lower the durability of the shoe. That is, in a shoe sole, high grip and high durability are in a trade-off relationship. In order to provide a shoe that has good grip and can be used for a long time, a shoe sole having appropriate hardness and relatively high strength is required.
However, Patent Document 1 does not disclose or suggest any relationship between the hardness and strength of the shoe sole.

Japanese Patent Application Publication No. 2005-139241

  An object of the present invention is to provide a shoe sole having an appropriate hardness and a relatively high strength.

Under the above-mentioned objectives, the present inventors have intensively studied a rubber composition capable of obtaining a shoe sole having an appropriate hardness. Specifically, when silica is blended with the rubber composition, the strength can be improved, but when silica is blended, the hardness increases with the strength, and it is found that the desired shoe sole cannot be obtained. Therefore, by examining various factors, it was found that when a primary alkylamine having 12 or more carbon atoms is blended, a shoe sole with low hardness can be obtained while maintaining high strength due to blending of silica. Surprisingly, the increase in strength and the decrease in hardness as described above can be realized by a combination of silica and a primary alkylamine having 12 or more carbon atoms.
Patent Document 1 does not disclose or suggest any reduction in hardness by a combination of silica and a primary alkylamine having 12 or more carbon atoms.

  The sole for shoes of the present invention includes a rubber component containing at least one of natural rubber and isoprene rubber, silica, and an amine compound, and the amine compound is a primary alkylamine having 12 or more carbon atoms. Yes, 35 parts by mass to 60 parts by mass of the silica are included with respect to 100 parts by mass of the rubber component.

In a preferred shoe sole of the present invention, the rubber component is composed of at least one of natural rubber and isoprene rubber.
In a preferable shoe sole of the present invention, the rubber component includes a first rubber composed of at least one of natural rubber and isoprene rubber, and a second rubber different from the first rubber. The mass ratio of rubber is 60:40 to 99.9: 0.1.
In another preferable shoe sole of the present invention, the primary alkylamine has 12 to 20 carbon atoms, and the primary alkylamine having 12 to 20 carbon atoms is added to 100 parts by mass of the rubber component. Contains 3 parts by mass or more.
Another preferred shoe sole of the present invention further comprises vegetable oil as a softening agent.

According to another aspect of the invention, a shoe is provided.
This shoe comprises one of the above shoe soles.

  Since the sole for shoes of the present invention has an appropriate hardness, it is possible to provide a shoe excellent in comfort by using this. Moreover, since the sole for shoes of this invention is comparatively excellent in intensity | strength, the shoe excellent in durability can be provided by using this.

1 is a side view of a shoe according to one embodiment of the present invention. Sectional drawing cut | disconnected by the II-II line | wire of FIG. The side view of the shoes of other embodiments of the present invention. The graph of the hardness of each shoe sole of Examples 1 and 2 and Comparative Examples 1 and 2. The graph figure of the tear strength of the sole for each said shoes. The graph of the optimal vulcanization time of the sole for each shoe. The graph of the hardness of each shoe sole of Examples 3 to 6 and Comparative Examples 3 to 7. The graph figure of the tear strength of the sole for each said shoes. The graph of the optimal vulcanization time of the sole for each shoe. The graph of the hardness of each shoe sole of Examples 7 to 8 and Comparative Examples 8 to 10. The graph figure of the tear strength of the sole for each said shoes. The graph which shows the stress-strain curve of each sole for shoes of Examples 9-11.

  Hereinafter, the shoe sole and shoes of the present invention will be described. In the present specification, the description “PPP to QQQ” means “PPP or more and QQQ or less”.

[Configuration of Shoes of the Present Invention]
1 and 2, a shoe 1a according to one embodiment of the present invention includes an upper 2a that covers an instep, a midsole 3a provided below the upper 2a, and a lower surface of the midsole 3a. And an outer sole 5a provided. The midsole 3a is attached to the lower end of the upper 2a. The outer sole 5a is attached over the entire lower surface of the midsole 3a. A method for attaching the midsole 3a and the outer sole 5a is not particularly limited, and representative examples include adhesion using an adhesive 4a. When the forming material of the outer sole 5a and the forming material of the midsole 3a have a property of adhering to each other, the outer sole 5a and the midsole 3a can be directly bonded. Moreover, the attachment method of the upper 2a and the midsole 3a is not specifically limited, For example, adhesion | attachment using an adhesive agent is mentioned. In the shoe 1a, the lower surface of the outer sole 5a is in contact with the ground.

In FIG. 3, a shoe 1b according to another embodiment of the present invention is provided with an upper 2b that covers an instep, a midsole 3b provided below the upper 2b, and a lower surface of the midsole 3b. A first outer sole 51b and a second outer sole 52b. In the shoe 1b, the areas of the outer soles 51b and 52b are both smaller than the area of the lower surface of the midsole 3b. Therefore, a part of the lower surface of the midsole 3b is exposed. In addition, in the shoe 1b of the example of FIG. 3, although two outer soles 51b and 52b whose area is smaller than the midsole 3b are provided, it is not limited to this. For example, only one outer sole having a smaller area than the midsole 3b may be provided, or three or more outer soles as described above may be provided (none of which are shown).
In FIG. 3, the first outer sole 51b is attached to the front of the lower surface of the midsole 3b, and the second outer sole 52b is attached to the rear of the lower surface of the midsole 3b. But arrangement | positioning of the outer sole with a small area is not restricted to the front or back of the midsole 3b, It can change suitably. In the shoe 1b, the lower surfaces of the outer soles 51b and 52b and a part of the lower surface of the midsole 3b are in contact with the ground.

The lower surfaces of the outer soles 5a, 51b, 52b are usually formed in an uneven shape as shown in the figure. However, it is not limited to such a concavo-convex shape, and the lower surface of all or at least one outer sole illustrated may be formed flat (not shown). Further, a plurality of separate studs may be attached to a lower surface of all or at least one outer sole shown (not shown).
The thicknesses of the outer soles 5a, 51b, 52b are not particularly limited, but are usually 1 mm or more, preferably 2 mm to 10 mm. Further, the thickness of the midsole 3a, 3b is not particularly limited, but is usually 3 mm or more, preferably 4 mm to 20 mm.

  The outer sole is a bottom member of the shoe in contact with the ground, and as described above, the outer sole can be used appropriately as a whole or part of the lower surface of the shoe. The outer sole is not limited to the bottom member that is always in contact with the ground. The concept of the outer sole includes a bottom member of a shoe that does not normally contact the ground but can be deformed by an external force (such as an impact at the time of landing) and touch the ground. Examples of the bottom member of the shoe that can be deformed by the external force and come into contact with the ground include a reinforcing member such as a shank member. The shank member is a bottom member disposed on the arch portion.

  The shoe sole of the present invention is usually used for the outer sole. In a shoe having a plurality of outer soles, the shoe sole of the present invention can be used for a part or all of the plurality of outer soles. Moreover, the sole for shoes of this invention can also be used for the said midsole. In this case, the shoe sole of the present invention may be used for both the midsole and the outer sole, or the shoe sole of the present invention is used for the midsole and other materials are used for the outer sole. Also good.

[Sole for shoes of the present invention]
The sole for shoes of this invention contains a rubber component, a silica, and an amine compound, and contains an additive as needed. The sole for shoes of the present invention can be obtained by molding a rubber composition containing a rubber component, silica, an amine compound, and additives in the required amounts.

(Rubber component)
The rubber component includes at least one of natural rubber and isoprene rubber, and may further include other rubber.
Here, the natural rubber is a rubber mainly composed of isoprene. The natural rubber and isoprene rubber are rubbers having substantially the same structure and physical properties. However, in the present invention, natural rubber refers to an isoprene polymer obtained from a tree, and the isoprene rubber is derived from petroleum. Refers to isoprene polymer. The molecular weight of the natural rubber and isoprene rubber is not particularly limited, and is, for example, 100,000 to 1,000,000.
The other rubber is not particularly limited as long as it is other than natural rubber and isoprene rubber. For example, diene rubber such as butadiene rubber (BR) and chloroprene (CR); styrene butadiene rubber (SBR), styrene butadiene styrene rubber ( Diene copolymer rubbers such as SBSR), acrylonitrile butadiene rubber (NBR), styrene isoprene copolymer (SIR), butyl rubber (IIR); ethylene containing ethylene units and units composed of α-olefins having 3 or more carbon atoms -Non-diene rubbers such as α-olefin copolymer rubber, urethane rubber, acrylic rubber, silicone rubber, and the like. The copolymer rubber may be a block copolymer or a random copolymer. The other rubbers can be used alone or in combination of two or more.

The rubber component is composed of at least one of natural rubber and isoprene rubber, or is composed of a first rubber composed of at least one of natural rubber and isoprene rubber and a second rubber different from the first rubber. The second rubber means a rubber other than natural rubber and isoprene rubber. Examples of the second rubber include the other rubbers.
When the rubber component is composed of at least one of the natural rubber and isoprene rubber, the rubber component is either natural rubber only, isoprene rubber only, or a mixture of natural rubber and isoprene rubber. In the case of comprising a first rubber composed of at least one of the natural rubber and isoprene rubber and a second rubber different from the first rubber, the rubber component comprises a mixture of natural rubber and other rubber, isoprene rubber and other rubber. Either a mixture or a mixture of natural rubber, isoprene rubber and other rubbers.
When the rubber component contains natural rubber and isoprene rubber, the compounding ratio (mass ratio) is not particularly limited, and is, for example, natural rubber: isoprene rubber (mass ratio) = 1: 99 to 99: 1. By blending a relatively large amount of natural rubber, a shoe sole having a large proportion of non-petroleum-derived components can be formed. In the present specification, “first rubber” is a general term for natural rubber and isoprene rubber, and “second rubber” refers to rubber other than natural rubber and isoprene rubber.
When the rubber component is a mixture of the first rubber and the second rubber, the compounding ratio (mass ratio) is not particularly limited. For example, the first rubber: second rubber (mass ratio) = 99.9: 0. It is 1-0.1: 99.9, Preferably, it is 80: 20-20: 80, More preferably, it is 70: 30-30: 70. Particularly preferably, the first rubber is blended in the same amount or more than the second rubber. Specifically, the first rubber: second rubber (mass ratio) = 50: 50-99. .9: 0.1, preferably 60:40 to 99.9: 0.1, more preferably 65:35 to 99.9: 0.1, and particularly preferably 70:30. ~ 99.9: 0.1. By increasing the ratio of the first rubber in the mixture of the first rubber and the second rubber, a shoe sole having relatively excellent strength can be obtained.

(silica)
The silica mainly functions as a reinforcing agent that reinforces the rubber component.
According to the classification based on the production method, the silica is a dry silica obtained by burning silicon tetrachloride in an oxyhydrogen flame; a wet silica obtained by neutralizing an alkali silicate with an acid; a silicon alkoxide A sol-gel method silica obtained by hydrolyzing an acid in an acidic or alkaline water-containing organic solvent; colloidal silica obtained by electrodialysis of an aqueous alkali silicate solution; and the like are known. In this invention, these silica can be used individually by 1 type or in combination of 2 or more types. In particular, since wet silica is easier to handle than other types of silica, it is preferable to use wet silica as the silica.

Although the average particle diameter of the said silica is not specifically limited, For example, it is 5 nm-500 nm, Preferably, it is 10 nm-200 nm, More preferably, it is 20 nm-100 nm. Silica having such a particle size is preferable because of its excellent reinforcement. The silica having the average particle diameter can be obtained by a known adjustment method. As the adjustment method, for example, a dry pulverization method for obtaining silica having a target average particle diameter using a jet mill or a ball mill; a silica having a target average particle diameter is obtained using a disper or a homogenizer. Wet-grinding method to be obtained.
The average particle diameter of the silica can be measured using a laser diffraction particle size distribution measuring device (product name “SK Laser Micron Sizer LMS-2000e” manufactured by Seishin Enterprise Co., Ltd.).

  The compounding amount of the silica is 35 parts by mass or more, preferably 40 parts by mass or more, and more preferably 45 parts by mass or more with respect to 100 parts by mass of the rubber component. By blending 35 parts by mass or more of silica, a relatively high strength shoe sole can be formed. Moreover, the compounding quantity of the said silica is 60 mass parts or less with respect to 100 mass parts of said rubber components, Preferably, it is 55 mass parts or less, More preferably, it is 50 mass parts or less. If the amount of silica is too large, the hardness may be too high.

(Amine compound)
The amine compound mainly functions as a vulcanization accelerator for the rubber component.
In the present invention, it is important to use a primary alkylamine having 12 or more carbon atoms. Preferably, a primary alkylamine having 12 to 20 carbon atoms is used, more preferably a primary alkylamine having 12 to 18 carbon atoms, and particularly preferably a primary alkylamine having 12 to 16 carbon atoms. Is used. The alkyl group of the primary alkylamine may be linear or branched, provided that it has 12 or more carbon atoms (preferably 12 to 20 carbon atoms). Preferably, a primary alkylamine having a linear alkyl moiety is used. The position of the amino group of the primary alkylamine is not particularly limited. A primary alkylamine having an amino group at the terminal of the alkyl group is preferably used.
One preferred primary alkylamine used in the present invention can be represented by R—NH ₂ . R represents a linear or branched alkyl group having 12 to 20 carbon atoms. The primary alkylamine can be synthesized from non-petroleum-derived or petroleum-derived raw materials. Preferably, a primary alkylamine synthesized from a non-petroleum-derived raw material is used.

  The blending amount of the primary alkylamine having 12 or more carbon atoms is not particularly limited. For example, it is 3 parts by mass or more, preferably 4 parts by mass or more, with respect to 100 parts by mass of the rubber component. Preferably, it is 5 parts by mass or more. By blending 3 parts by mass or more of a primary alkylamine having 12 or more carbon atoms, a sole for shoes having a low hardness (for example, a hardness of 65 or less) can be configured. Moreover, the upper limit of the blending amount of the primary alkylamine having 12 or more carbon atoms is not particularly limited. Yes, more preferably 8 parts by mass or less, and particularly preferably 7 parts by mass or less. If the blending amount of the primary alkylamine having 12 or more carbon atoms is too large, the hardness becomes too low, and the amine compound is precipitated on the surface of the sole, so that a shoe sole having a poor appearance may be obtained.

(Additive)
Examples of the additive include softeners, crosslinking agents, crosslinking aids, fillers, weathering agents, antioxidants, ultraviolet absorbers, lubricants, antistatic agents, and dispersants. These are appropriately selected and blended in the rubber composition.
The softening agent has a function of improving the flexibility of the shoe sole. Examples of the softening agent include mineral oils such as process oil and extender oil; vegetable oils such as tall oil fatty acid, castor oil, and linseed oil. By using vegetable oil as a softening agent, a sole for shoes having a large proportion of non-petroleum-derived components can be formed. The blending amount of the softening agent is not particularly limited, but for example, with respect to 100 parts by mass of the rubber component, it is more than 0 and 20 parts by mass or less, preferably 1 part by mass to 20 parts by mass, more preferably, 3 parts by mass to 15 parts by mass. By blending a softener, a shoe sole having more flexibility can be constructed.

  The crosslinking agent is not particularly limited, and examples thereof include sulfur-containing compounds and organic peroxides. In particular, a compound containing sulfur is preferable because crosslinking is promoted by the primary alkylamine. Examples of the compound containing sulfur include sulfur, sulfur halide, di-2-benzothiazolyl disulfide, N-oxydiethylene-2-benzothiazolylsulfenamide, and the like. Although the compounding quantity of the said crosslinking agent is not specifically limited, For example, it is 0.5 mass part-10 mass parts with respect to 100 mass parts of rubber components, Preferably it is 0.5 mass part-5 mass parts.

  The crosslinking aid is not particularly limited, and examples thereof include zinc oxide, metal oxides other than zinc, metal hydroxides, and fatty acids. Examples of the metal oxide other than zinc include magnesium oxide and lead monoxide. Examples of the metal hydroxide include calcium hydroxide. Examples of fatty acids include stearic acid and oleic acid. The crosslinking aids can be used alone or in combination of two or more. It is preferable to use at least zinc oxide as a crosslinking aid because of its excellent crosslinking promotion effect. Although the compounding quantity of the said crosslinking adjuvant is not specifically limited, For example, it is 1.0 mass part-10 mass parts with respect to 100 mass parts of rubber components, Preferably it is 1.5 mass parts-8 mass parts. .

  The filler is not particularly limited, and examples thereof include calcium carbonate, magnesium carbonate, magnesium oxide, and titanium oxide.

(Sole sole manufacturing method)
The shoe sole of the present invention can be obtained by kneading a rubber composition containing the rubber component, silica, amine compound and additives in the required amounts and molding the kneaded product. The temperature during kneading of the rubber composition is usually 140 ° C. or lower, preferably 130 ° C. or lower. When kneaded at an excessively high temperature, the rubber component may start to be crosslinked. The kneading can be performed using an open roll, a Banbury mixer, a kneader, a twin screw extruder, or the like.
The rubber composition can be molded by placing in a suitably shaped mold and heating. By heating, the rubber component is crosslinked through a crosslinking agent, and a shoe sole having rubber elasticity is obtained. The molding temperature of the rubber composition is preferably 145 ° C to 200 ° C, more preferably 155 ° C to 180 ° C.

  Since the sole for shoes of the present invention contains a rubber component, a predetermined amount of silica, and a primary alkylamine having 12 to 20 carbon atoms, it has an appropriate hardness and is excellent in strength. Specifically, in general, in order to obtain a shoe having good grip properties, the hardness (A hardness) of the shoe sole is preferably 45 to 65, more preferably 50 to 65, and particularly preferably 50 to 60. preferable. Further, in order to obtain a shoe having excellent durability, the strength (tear strength) of the shoe sole is preferably 50 kgf / cm or more, more preferably 60 kgf / cm or more, and particularly preferably 65 kgf / cm or more. According to the present invention, a shoe sole having the above hardness and strength can be obtained relatively easily.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples. However, the compounding ratio of each component of each table | surface is a mass part.

[Materials used]
(1) Polyisoprene rubber (first rubber): manufactured by Nippon Zeon Co., Ltd., product name “Nipol IR220”. The weight average molecular weight is about 390,000.
(2) Butadiene rubber (second rubber): manufactured by Nippon Zeon Co., Ltd., product name “Nipol BR220”. The weight average molecular weight is about 430,000.
(3) n-octylamine (primary alkylamine having 8 carbon atoms): Product name “Armin 8D” manufactured by Lion Corporation.
(4) n-decylamine (primary alkylamine having 10 carbon atoms): manufactured by Tokyo Chemical Industry Co., Ltd., product name “decylamine”.
(5) n-dodecylamine (primary alkylamine having 12 carbon atoms): Product name “Armin 12D” manufactured by Lion Corporation.
(6) n-octadecylamine (primary alkylamine having 18 carbon atoms): Product name “Armin 18D” manufactured by Lion Corporation.
(7) Silica (reinforcing agent): wet silica having an average particle diameter of 20 nm. Product name “Ultrasil VN3” manufactured by Evonik-Degussa.
(8) Paraffin oil (softener): Product name “Process Oil P200” manufactured by JX Nippon Oil & Energy Corporation.
(9) Tall oil fatty acid triglyceride (softener): manufactured by Harima Kasei Co., Ltd.
(10) Stearic acid (crosslinking aid): manufactured by Shin Nippon Rika Co., Ltd.
(11) Active zinc white (crosslinking aid): manufactured by Honso Chemical Co., Ltd.
(12) Sulfur (crosslinking agent): manufactured by Hosoi Chemical Co., Ltd.

[Measurement method of hardness]
Hardness was measured by the following method based on JIS K 6253.
Using a spring type hardness tester type A, the measurement surface having a thickness of 12 mm or more is brought into contact with the pressure surface of the test device so that the push needle of the test device is perpendicular to the test piece measurement surface. The scale was read immediately after the pressing needle was pressed against the sample with a load of 9.81N. The measurement sample is obtained by stacking a plurality of test pieces formed in Examples and Comparative Examples described later to be 12 mm or more.

[Measurement method of tear strength]
The tear strength was measured by the following method based on JIS K6252.
Using a tensile tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., product name “STROGRAPH-R2”), both ends of the test pieces formed in the examples and comparative examples described later are gripped by the chuck of the tester, and 500 mm / min Pulling was continued until the sample broke at a speed. Then, the tear strength was calculated from the load at the time of fracture and the thickness of the sample before being pulled.

[Measurement method of optimum vulcanization time]
The optimum vulcanization time was measured by using a rotorless rheometer (product name “EKT2000S / SP”, manufactured by EKTRON TEK CO. LTD) of a rubber composition after kneading and before heating and pressurization. At this time, the time change of the torque accompanying the crosslinking reaction at 165 ° C. was measured for 20 minutes, and the time when the torque reached 90% of the maximum value was determined as the optimum vulcanization time.

[How to create a stress-strain curve]
The stress-strain curve of the shoe sole was prepared by forming a test sample into a dumbbell-shaped No. 3 shape described in JIS K 6251, and preparing a sample for measurement. The sample was then converted into an autograph precision universal testing machine (Shimadzu Corporation). Using a product name “AG-50kNIS MS type” manufactured by Seisakusho Co., Ltd.), the film was pulled at 23 ° C. at a pulling speed of 500 mm / sec.

[Outline of Examples and Comparative Examples]
In Examples 1 and 2 and Comparative Examples 1 and 2, it was demonstrated how the hardness of the shoe sole is affected by the difference in the number of carbon atoms and the blending amount of the primary alkylamine.
In Examples 3 to 6 and Comparative Examples 3 to 7, it was demonstrated how the hardness of the shoe sole is affected by the difference in the blending amount of the primary alkylamine and the blending amount of the isoprene rubber. .
In Examples 7 to 8 and Comparative Examples 8 to 10, it was demonstrated how the hardness of the shoe sole is affected by the difference in the blending amount of the primary alkylamine and the blending amount of the silica.
In Examples 9 to 11, the flexibility of the shoe sole was demonstrated.

[Examples 1A to 1D]
Example 1 (Examples 1A to 1D) is a group in which dodecylamine was used as the amine compound and the ratio was changed.
Specifically, a rubber composition having a compounding ratio of each component shown in Table 1 was prepared. In all tables, the numerical value of each component is expressed in parts by mass. This rubber composition was kneaded using a kneader (DSS-10MWB-E type) at a discharge temperature of 130 to 140 ° C. to obtain a kneaded product. Next, this kneaded material was pressed using a press at 165 ° C. and a pressure of about 14.7 MPa for an optimum vulcanization time, and a sheet having a length of 130 mm, a width of 210 mm, and a thickness of 2 mm was produced. The sheet was cut into an angle shape specified in JIS K 6252 to prepare a plurality of test pieces, and the hardness and tear strength were measured using the test pieces. The results are shown in Table 1. However, the tear strength of Example 1A could not be measured due to an unknown cause. However, it is estimated that the tear strength of Example 1A also shows the same tendency as the tear strength of Example 2.
Further, the optimum vulcanization time of the kneaded product (rubber composition after kneading and before heating and pressing) was measured. The results are also shown in Table 1.

[Examples 2A to 2D]
Example 2 (Examples 2A to 2D) is a group in which octadecylamine was used as the amine compound and the ratio was changed.
In Example 2, a sheet was prepared in the same manner as in Example 1 except that the rubber composition having the compounding ratio of each component shown in Table 1 was used, and the hardness and tear strength were measured. Similarly, the optimum vulcanization time was measured for the rubber composition of Example 2. The results are shown in Table 1.

[Comparative Examples 1A to 1D]
Comparative Example 1 (Comparative Examples 1A to 1D) is a group in which octylamine is used as the amine compound and the ratio thereof is changed.
In Comparative Example 1, a sheet was prepared in the same manner as in Example 1 except that a rubber composition having a compounding ratio of each component shown in Table 2 was used, and the hardness and tear strength were measured. Similarly, the optimum vulcanization time was measured for the rubber composition of Comparative Example 1. The results are shown in Table 2.

[Comparative Examples 2A to 2D]
Comparative Example 2 (Comparative Examples 2A to 2D) is a group in which decylamine was used as the amine compound and the ratio was changed.
In Comparative Example 2, a sheet was prepared in the same manner as in Example 1 except that the rubber composition having the compounding ratio of each component shown in Table 2 was used, and the hardness and tear strength were measured. Similarly, the optimum vulcanization time was also measured for the rubber composition of Comparative Example 2. The results are shown in Table 2.

[Evaluation by difference in carbon number and blending amount of primary alkylamine]
FIG. 4 is a graph summarizing the hardnesses of Examples 1 and 2 and Comparative Examples 1 and 2, FIG. 5 is a graph summarizing the tear strengths, and FIG. It is the graph which summarized sulfurating time.
Referring to these figures, Examples 1 and 2 using a primary alkylamine having 12 or more carbon atoms have a hardness higher than those of Comparative Examples 1 and 2 using a primary alkylamine having 10 or less carbon atoms. It became low. In particular, it can be seen that when 3 to 8 parts by mass of a primary alkylamine having 12 or more carbon atoms is blended, a shoe sole having a hardness of 50 to 60 can be obtained. In addition, about the tear strength of the sole for shoes, it became large in general in proportion to the compounding quantity of the primary alkylamine. Therefore, no significant difference was observed in the strength depending on the number of carbon atoms of the primary alkylamine. However, it was found that even when a primary alkylamine having 12 or more carbon atoms was blended, a shoe sole excellent in durability having a tear strength of 60 kgf / cm or more was obtained. Further, the optimum vulcanization time of the rubber composition showed almost the same tendency regardless of the carbon number. That is, when a primary alkylamine is blended, the optimum vulcanization time is accelerated in proportion to the blending amount.

[Examples 3A to 3C]
Example 3 (Examples 3A to 3C) is a group in which isoprene rubber is used as a rubber component and octadecylamine is used as an amine compound, and the ratio of the amine compound is changed.
In Example 3, a sheet was prepared in the same manner as in Example 1 except that a rubber composition having a compounding ratio of each component shown in Table 3 was used, and the hardness and tear strength were measured. Similarly, the optimum vulcanization time was measured for the rubber composition of Example 3. The results are shown in Table 3.

[Examples 4A to 4C, 5A to 5C, and 6A to 6C]
Example 4 (Examples 4A to 4C), Example 5 (Examples 5A to 5C) and Example 6 (Examples 6A to 6C) use a mixture of isoprene rubber and butadiene rubber as a rubber component and as an amine compound. This is a group using octadecylamine and changing the ratio of the amine compound.
In Examples 4, 5 and 6, a sheet was prepared in the same manner as in Example 1 except that the rubber composition having the compounding ratio of each component shown in Tables 3 and 4 was used, and the hardness and tear strength were determined. It was measured. Similarly, the optimum vulcanization time was measured for the rubber composition of Example 3. The results are shown in Tables 3 and 4.

[Comparative Examples 3 to 6]
In Comparative Examples 3 to 6, sheets were prepared in the same manner as in the corresponding Examples 3 to 6 except that no amine compound was blended, and the hardness and tear strength were measured. The results are shown in Tables 3 and 4.

[Comparative Examples 7A to 7D]
Comparative Examples 7A to 7D are groups in which butadiene rubber is used as the rubber component and octadecylamine is used as the amine compound, and the ratio of the amine compound is changed.
In Comparative Example 7, a sheet was prepared in the same manner as in Example 1 except that the rubber composition having the compounding ratio of each component shown in Table 4 was used. Similarly, hardness, tear strength, and optimum vulcanization time were used. Was measured. The results are shown in Table 4.

[Evaluation by difference in blending amount of primary alkylamine and isoprene rubber]
FIG. 7 is a graph summarizing the hardnesses of Examples 3 to 6 and Comparative Examples 3 to 7, FIG. 8 is a graph summarizing the tear strengths, and FIG. It is the graph which summarized sulfurating time.
Referring to these figures, Examples 3 to 6 containing isoprene rubber had lower hardness and shorter optimum vulcanization time than Comparative Example 7 containing no isoprene rubber. .
Moreover, Examples 3 to 6 containing isoprene rubber showed a tendency to be generally higher in tear strength than Comparative Example 7 containing no isoprene rubber. Among them, the tear strength tends to be higher as the amount of isoprene rubber is increased. In particular, it can be seen that when blending more than 50 parts by mass of isoprene rubber, the strength increases in synergy with the blending amount of the primary alkylamine.

[Examples 7A to 7C and 8A to 8C]
Example 7 (Examples 7A to 7C) is a group in which 50 parts by mass of silica is blended and the ratio of octadecylamine is changed. Example 8 (Examples 8A to 8C) is a group in which 40 parts by mass of silica is blended and the ratio of octadecylamine is changed.
In Example 7 and Example 8, sheets were prepared in the same manner as in Example 1 except that the rubber composition having the compounding ratio of each component shown in Table 5 was used, and the hardness and tear strength were measured. The results are shown in Table 5.

[Comparative Examples 8A to 8C, 9A to 9C, and 10A to 10C]
Comparative Example 8 (Comparative Examples 8A to 8C) is a group in which 30 parts by mass of silica is blended and the ratio of octadecylamine is changed.
Comparative Example 9 (Comparative Examples 9A to 9C) is a group in which 20 parts by mass of silica is blended and the ratio of octadecylamine is changed.
Comparative Example 10 (Comparative Examples 10A to 10C) is a group in which the proportion of octadecylamine was changed without adding silica.
Comparative Examples 8, 9 and 10 were prepared in the same manner as in Example 1 except that rubber compositions having the compounding ratios of the respective components shown in Tables 5 and 6 were used, and the hardness and tear strength were determined. It was measured. The results are shown in Tables 5 and 6.

[Evaluation by difference in blending amount of primary alkylamine and silica]
FIG. 10 is a graph summarizing the hardnesses of Examples 7 and 8 and Comparative Examples 8 to 10, and FIG. 11 is a graph summarizing the tear strengths.
Referring to these figures, Examples 7 and 8 in which 40 to 50 parts by mass of silica were blended had a hardness of 45 to 65 regardless of the blending amount of the primary alkylamine having 12 or more carbon atoms. . From this result, when silica is blended in an amount of 35 to 60 parts by mass, it is estimated that a shoe sole having an appropriate hardness can be obtained.
On the other hand, also regarding the tear strength, Examples 7 and 8 containing 40 to 50 parts by mass of silica showed a relatively high value regardless of the amount of the primary alkylamine having 12 or more carbon atoms.

[Examples 9 to 11]
In Example 9, no softener was blended, in Example 10, paraffin oil (mineral oil) was blended as a softener, and in Example 11, tall oil fatty acid (vegetable oil) was blended as a softener.
In Examples 9 to 11, test pieces were prepared in the same manner as in Example 1 except that the rubber composition having the compounding ratio of each component shown in Table 7 was used. A stress-strain curve was created using the test piece. The result is shown in the graph of FIG. In the graph of FIG. 12, the horizontal axis represents strain, and the vertical axis represents stress.
As shown in FIG. 12, the sole for shoes containing vegetable oil was superior in flexibility as compared to the sole containing mineral oil.

  The shoe sole of the present invention can be used as a constituent member of various shoes.

1a, 1b Shoes 2a, 2b Shoes upper 3a, 3b Shoes midsole (sole for shoes)
5a, 51b, 52b Shoes outer sole (sole for shoes)

Claims (6)

A rubber component containing at least one of natural rubber and isoprene rubber, silica, and an amine compound,
The amine compound is a primary alkylamine having 12 or more carbon atoms;
The sole for shoes which contains 35-60 mass parts of said silica with respect to 100 mass parts of said rubber components.   The shoe sole according to claim 1, wherein the rubber component is composed of at least one of natural rubber and isoprene rubber.   The rubber component includes a first rubber composed of at least one of natural rubber and isoprene rubber, and a second rubber different from the first rubber, and a mass ratio of the first rubber to the second rubber is 60:40. The sole for shoes according to claim 1, which is ˜99.9: 0.1. The primary alkylamine has 12 to 20 carbon atoms;
The shoe sole according to any one of claims 1 to 3, comprising 3 parts by mass or more of the primary alkylamine having 12 to 20 carbon atoms with respect to 100 parts by mass of the rubber component.   Furthermore, the sole for shoes as described in any one of Claims 1 thru | or 4 containing a vegetable oil as a softening agent.   A shoe comprising the shoe sole according to any one of claims 1 to 5.

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