JP3202782B2 - Rubber composition and tire using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition and a tire using the same as a rubber for a side portion of a tire. In this specification, the side portion means a portion composed of sidewall rubber, white line rubber, and decorative characters.

[0002]

2. Description of the Related Art Conventionally, trucks, heavy vehicles for construction,
Side parts of pneumatic tires, such as tires for agricultural vehicles, aircraft, passenger cars, motorcycles, and racing cars, contain ozone,
There has been a disadvantage that it is strongly deteriorated by ultraviolet rays, and as a result, cracks are generated and the appearance of the side part is impaired.
Therefore, in order to improve the weather resistance of the side portion, an amine-based antioxidant is blended with the rubber composition constituting the side portion, or, in addition to the highly unsaturated rubber, a low unsaturated rubber having few double bonds. Rubber has been made to blend.
In the latter rubber composition, in order to improve vulcanizability and the like, the following formula is contained in the rubber composition.

Embedded image TMTD (tetramethylthiuram disulfide) represented by
It is known to mix a thiuram-based compound such as the above or a peroxide compound.

[0003]

However, in a rubber composition containing an amine-based anti-aging agent, the anti-aging agent blooms on the surface of a rubber product such as a tire, discolors the surface to a brown color, and the side portion of the tire When used as, the appearance is impaired. In addition, in the case of white rubber and decorative characters, the brown color is fatal, so that the amine antioxidant cannot be used. Furthermore, non-staining phenolic antioxidants and hindered amine antioxidants have insufficient ozone resistance and are therefore difficult to use as side rubbers. Therefore, blends of highly unsaturated rubber and low unsaturated rubber are used for the side parts (sidewalls, white lines and decorative characters) where emphasis is placed on appearance, but in TMTD compounded rubber compositions, low unsaturated rubber is used. And the highly unsaturated rubber have insufficient co-vulcanizability, and have poor compatibility with the rubber, thus causing problems such as blooming. Furthermore, the co-vulcanizability with the adjacent rubber is also poor. On the other hand, vulcanization with peroxide is inferior in mechanical strength as compared with vulcanization of sulfur using a vulcanization accelerator and is inconvenient.

[0004] Further, as a technique of blending EPDM, halogenated butyl rubber and diene rubber to achieve both weather resistance and flex fatigue resistance, US Pat. No. 3,630,974 and JP-A-55-3478 disclose a technique. It has already been disclosed. However, these technologies do not describe the vulcanization method,
Moreover, the co-vulcanizability of these rubber compositions is at a low level.

On the other hand, vulcanization methods for these blended rubbers generally use a thiuram compound or dithiocarbamate compound having a short alkyl group such as TMTD or TETD, a benzothiazole vulcanization accelerator and sulfur. (Edited by The Rubber Association of Japan, "Special Synthetic Rubber 10 Courses" p24). However, since this vulcanization system focuses on increasing the vulcanization rate and increasing the vulcanization density, it cannot be said that the co-vulcanizability is always sufficient.

[0006] In view of the above disadvantages, the present invention provides a co-vulcanizable,
An object of the present invention is to provide a rubber composition which is excellent in weather resistance and the like and is non-staining, and a tire using the same in a side portion.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have combined a compound selected from the group consisting of a specific thiuram compound and a specific dithiocarbamate compound with a benzothiazole vulcanization accelerator. It has been found that the above objects can be achieved by using them together.

The configuration of the present invention is as follows. That is,
The rubber composition of the present invention is based on 100 parts by weight of a component consisting of EPDM, a halogenated butyl rubber, and a diene rubber by weight,
Next formula

Embedded image (In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a straight-chain or branched-chain alkyl group having 7 to 12 carbon atoms, preferably 8 carbon atoms); and Next formula

Embedded image (Wherein, R ₅ and R ₆ each independently represent a carbon number of 7 to 12,
Preferably a straight or branched alkyl group of 8;
Is a divalent or higher valent metal, and n is a number equal to the valency of the metal of M)) at least one of the compounds selected from the group consisting of dithiocarbamate compounds
1 to 2.0 parts by weight, and benzothiazole vulcanization accelerator 0.
Add 5 to 3.0 parts by weight.

The ratio of the benzothiazole vulcanization accelerator to a compound selected from the group consisting of the thiuram compound and the dithiocarbamate compound is 1.0 to 5.0.
Is preferable. Further, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and
It is preferred that each of R ₆ is a 2-ethylhexyl group, M is antimony, and n is 3.

[0010] Further, when the rubber component is 90 ≧ 2 × A + B ≧
It is preferable to satisfy the relationship of 70 and C ≧ 20 (where A represents parts by weight of EPDM, B represents parts by weight of halogenated butyl rubber, and C represents parts by weight of diene rubber). Furthermore, it is preferable to use each of the rubber compositions for a rubber on a side portion of a tire,
For example, tires for trucks, aircraft, agricultural vehicles, large construction vehicles, passenger vehicles, motorcycles, and racing cars can be mentioned.

The above rubber compositions can be produced by kneading with a conventional mixer or kneader. At this time, if necessary, fillers such as carbon black, calcium carbonate, titanium dioxide, clay, talc, alumina, silica, etc., processable softeners, non-staining anti-aging agents, resins, stearic acid, zinc oxide, etc. Vulcanization accelerating aids, vulcanizing agents such as sulfur, processing aids such as tackifiers, and the like can be added. When used as the rubber for the side portion of the tire, it can be carried out by a normal tire manufacturing method.

Here, as the diene rubber, natural rubber (NR), synthetic natural rubber (IR), styrene butadiene rubber (SBR), polybutadiene rubber (BR), chloroprene rubber (CR) and nitrile rubber (NBR, NIR) NBIR) and the like.

If the amount of the compound selected from the group consisting of the thiuram compound and the dithiocarbamate compound is less than 0.1 part by weight, for example, when used as a rubber for the side portion, a sufficient vulcanization density cannot be obtained, which is disadvantageous. If the content is more than 2.0 parts by weight, for example, when the rubber is used as a side portion rubber, the vulcanization density is too high, and the bending fatigue resistance and the like are inferior. R ₁ , R ₂ , R ₃ and R ₄ have 6 carbon atoms
In the following, the dispersion in the rubber becomes poor, and the heat resistance and the like are inferior, and when it is 13 or more, the vulcanization rate is extremely slow, which is disadvantageous.

Similarly, when the carbon number of R ₅ and R ₆ is 6 or less, the dispersion in the rubber becomes poor, and the elastic modulus is inconvenient, and when the carbon number is 13 or more, the vulcanization rate becomes very low. Metals of M include antimony, iron, copper, zinc, nickel, lead, tellurium and the like. However, when M is monovalent, the effect of accelerating vulcanization is insufficient. It is.

The benzothiazole vulcanization accelerators include mercaptobenzothiazole (MBT), dibenzothiazyldisulfide (MBTS), Nt-butyl-2-benzothiazolylsulfenamide (TBBS), Cyclohexyl-2-benzothiazolylsulfenamide (CBS),
N-oxydiethylene-2-benzothiazolylsulfenamide (MBS), N, N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS), zinc salt of mercaptobenzothiazole, 2- (4-morpholinodithio ) Benzothiazole, 2- (2,4-dinitro-phenyl) -mercaptobenzothiazole, salts of mercaptobenzothiazole and cyclohexylamine, N, N-diethylthiocarbamoyl-2-benzothiazolyl sulfide, and the like, Preferably, it is MBTS or MBT, and if it is less than 0.5 part by weight, for example, when it is used as a rubber for the side part, it is inconvenient because a sufficient vulcanization density cannot be obtained. This is disadvantageous because the vulcanization density is too high.

Further, when the ratio of the benzothiazole-based vulcanization accelerator to the compound selected from the group consisting of the thiuram compound and the dithiocarbamate compound is less than 1.0, the phase surplus effect on the vulcanization density is reduced, which is desirable. In order to obtain a vulcanized density, a larger amount is required.
As a result, the advantage of processing stability is reduced, which is inconvenient. On the other hand, if it is more than 5.0, the effect of the surplus on the vulcanization density is similarly reduced, so that a larger amount is required to obtain the desired vulcanization density. In addition, the vulcanization rate is greatly reduced, which is disadvantageous in terms of productivity. Furthermore, the co-vulcanizability is poor and the mechanical properties are not satisfactory.

Here, the rubber component is 90 ≧ 2 × A +
The requirement that the relationship of B ≧ 70 and C ≧ 20 is satisfied is as follows.
For example, this is because the weather resistance, bending fatigue resistance, and co-vulcanization properties when used as the rubber for the side portion are considered. 2 x A
If the value of + B is less than 70, the weather resistance is poor, and it is inconvenient when used as a rubber for the side portion. Also, 2 × A + B ≦
The reason for setting the value to 90 is to take into account the bending fatigue resistance. 2
When the value of × A + B exceeds 90, the bending fatigue resistance is inferior, which is not preferable. Also, if the diene rubber is less than 20 parts by weight, the flex fatigue resistance is similarly poor, and when used as a sidewall rubber for a tire, it is co-vulcanized with an adjacent tread rubber, ply coating rubber, or the like. When used for white line rubber or decorative characters of tires, it is inferior in co-vulcanizability with the adjacent sidewall rubber and causes interfacial peeling. Further, the content of the halogenated butyl rubber in the raw rubber is preferably 70 parts by weight or less. If it exceeds 70 parts by weight,
There is a risk of scorch even with the vulcanization accelerator of the present invention,
Not preferred.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. Example A (Examples 1 to 5, Comparative Examples 1 to 4) Table 1 shows the mixing ratio (unit: parts by weight) of the rubber composition, the physical properties of the rubber composition, and the sidewall of a tire. Shows the characteristics of the tire used for rubber. In Example A, in each of Examples and Comparative Examples, the rubber component was 90 ≧ 2.
× A + B ≧ 70 and C ≧ 20 (where A is EP
Parts by weight of DM, B represents parts by weight of chlorinated butyl rubber (Cl-IIR), and C represents parts by weight of natural rubber (NR)). That is, the effect of the vulcanization accelerator specified by the present invention was confirmed for rubber components having excellent weather resistance.

As thiuram compounds, TEHT, TOTD
And TMTD (outside the scope of the present invention), EH-Sb and EH-Zn were used as dithiocarbamate compounds, and MBTS was used as a benzothiazole vulcanization accelerator. Further, the present invention achieves the intended purpose by using a compound selected from the group consisting of a thiuram compound and a dithiocarbamate compound in combination with a benzothiazole vulcanization accelerator. From 3 to
A case in which any of the components was omitted, and a case where TMTD outside the scope of the present invention was used as the tyrium compound in Comparative Example 4 was shown, and a comparison with each example was performed. The amount of TMTD of Comparative Example 4 was the same as the molar amount of TEHT of Example 1.

Each test method is as follows. Vulcanization rate Measured at 155 ° C. using an oscillating desk rheometer manufactured by Nippon Synthetic Rubber Co., Ltd. In the table, T90 is the maximum torque value.
The time required to obtain 90% is shown, and a smaller value indicates a faster vulcanization rate, which is preferable.

Processing stability Measured at 130 ° C. using a Mooney viscometer manufactured by Shimadzu Corporation. The test method was performed according to JIS K6300, and T5 (unit: minute) was determined. Larger values indicate better processing stability and are preferred.

Strength at break, modulus of elasticity Measured according to the tensile test method of JIS K6301. Using a dumbbell-shaped No. 3 sample, the elastic modulus at 300% elongation and the strength at break were measured. The modulus of elasticity is proportional to the vulcanization density, and a larger value indicates a higher vulcanization density, which is preferable as a vulcanization accelerator. The strength at break indicates co-vulcanizability, and the larger the value, the better the co-vulcanizability and the more preferable.

Ozone resistance Measured according to the JIS K6301 ozone deterioration test method. Using a strip sample, the measurement was performed at an ozone concentration of 50 pphm and a temperature of 40 ° C.
50% strain was applied, and the occurrence of cracks after 200 hours was confirmed. In the table, the symbol "O" indicates that no crack was generated. It is preferable that the occurrence of cracks is small as the side rubber.

Bloom property The vulcanized strip sample was allowed to stand at room temperature, and after 60 days, the presence or absence of blooming was observed. ○ in the table indicates no blooming, ×
Indicates that blooming is occurring. It is desirable that the blooming does not occur in the appearance of the side portion.

Flexural fatigue resistance A DeMattia test was performed according to ASTM D430. Table 1 shows Comparative Example 4, Table 2 shows Comparative Example 4, Table 3
The number of bends until the cracks of Comparative Example 6 and Comparative Example 8 and 9 in Table 4 (Example 16 is based on Comparative Example 8 and Example 17 is based on Comparative Example 9) is 100, Exponential display. A larger value indicates better flex fatigue resistance, which is preferable.

Peel Strength The rubber compositions of the respective formulations were laminated with the same rubber and different rubbers and vulcanized, and a peel test was performed. The test method was performed in accordance with JIS K6301, and Comparative Examples 4, 5, 6,
The peel strengths of the samples 8 and 9 were set to 100, and the results were indexed (Example 16 is based on Comparative Example 8 and Example 17 is based on Comparative Example 9). The larger the value, the greater the peel strength and the better the co-vulcanizability with the adjacent rubber, indicating that it is preferable. Table 5 shows the compounding (unit: parts by weight) of the different rubbers used. This compounding is a general compounding of carcass ply rubber.

Tire Peeling Strength In Example A, a tire was manufactured using each compounded rubber composition as a side wall rubber, and the tire was moved on a drum at a speed of 60 km / h.
After running 10,000 km, the peeling strength between adjacent rubber (tread and carcass ply) was measured (JIS K630
1). At this time, the tread rubber is composed of a rubber composition of a general tread composition containing SBR as a main component, and the carcass ply is composed of a rubber composition of the composition shown in Table 5.

In Examples B and C (described later), a tire (white line) in which the rubber composition (white rubber) of each compound was arranged in a circle on the tire side was manufactured, and a similar test was performed. Done. At this time, the sidewall rubber adjacent to the white rubber was a mixture of a diene rubber as a main component, and the mixture (unit: parts by weight) is shown in Table 6. The peel strengths of Comparative Example 4 in Table 1, Comparative Example 5 in Table 2, and Comparative Example 6 in Table 3 were each represented by an index, with 100 being the strength.
The larger the value, the better the co-vulcanizability with the adjacent rubber,
This shows that the tire has excellent durability.

[0029]

[Table 1] Description of abbreviations TEHT tetrakis2-ethyl hexyl thiuram disulfid
e) TOTD tetraoctylthiuram disulfide (tet
ra octhyl thiuram disulfide) TMTD Tetramethylthiuram disulfide
methyl thiuram disulfide) EH-Sb Anti-2-ethylhexyl dithiocarbamate Antimony (Antimony di 2-ethyl hexyl dithiocar
bamate) EH-Zn di 2-ethylhexyl dithiocarbamate Zinc (Zinc di 2-ethyl hexyl dithiocarbamate) TBBS Nt-butyl-2-benzothiazolylsulfenamide

As described above, the rubber compositions of Examples 1 to 5 using a combination of a compound selected from the group consisting of a thiuram compound and a dithiocarbamate compound and a benzothiazole vulcanization accelerator, High speed and excellent processing stability. Further, it can be seen that the strength at break is large and the co-vulcanizability is excellent. The elastic modulus is larger than that of Comparative Examples 1 to 3, and it can be seen that a synergistic effect of the thiuram compound and / or the dicarbamate compound and the benzothiazole-based vulcanization accelerator appears. In addition, the ozone resistance is more strongly affected by the rubber component than by the vulcanization accelerator, but since each compound satisfies the above two formulas, the ozone resistance (weather resistance) is a good result. Could be obtained. Bloom is also excellent. Despite the high modulus, the flex fatigue resistance is greatly improved, presumably due to improved co-vulcanizability. Peel strength is greatly improved. This property is
It shows the co-vulcanizability with the adjacent rubber (compounding in Table 5), and the effect of the present invention is remarkably exhibited.

On the other hand, from Comparative Examples 1 and 2, when one type of vulcanization accelerator selected from the group consisting of the thiuram compound and the dicarbamate compound was added, the There is little improvement, and the improvement in peel strength with different types of rubber, that is, the improvement in co-vulcanization, is small. Although the flex fatigue resistance appears to be slightly improved, this is due to the significantly lower modulus and is not an essential improvement. In Comparative Example 3, the vulcanization rate was slow, the elastic modulus was low, and the peel strength was significantly poor. Also, from Comparative Example 4, when TMTD outside the scope of the present invention was used as the thiuram compound and a benzothiazole-based vulcanization accelerator was further blended, the same vulcanization rate as in the example can be obtained. It can be seen that they are inferior in blooming property, strength at break, peel strength, and bending fatigue resistance. Furthermore, the co-vulcanizability of this rubber composition with the adjacent rubber of the tire used for the sidewall of the tire is as follows:
It can be seen that the rubber composition is larger than the rubber composition of each comparative example and is excellent as a sidewall rubber.

Example B (Examples 6 to 13, Comparative Example 5) Similarly, Table 2 shows the mixing ratio (unit: parts by weight) of the rubber composition, the physical properties of the rubber composition, and the rubber composition. The characteristics of the tire used for the white line rubber on the tire side are shown. As in Example A, Example B satisfies the relationship of 90 ≧ 2 × A + B ≧ 70 and C ≧ 20 in the rubber components in each of Examples and Comparative Examples. In other words, the effect of the vulcanization accelerator specified by the present invention was confirmed for rubber components having excellent weather resistance. Example A contains carbon black, but Example B contains carbon black. Since it is an example applied to white rubber, it differs in that calcium carbonate is compounded.

Further, TEHT and TMTD are used as thiuram compounds.
(Outside the scope of the present invention), and EH-Sb was used as the dithiocarbamate compound. MBTS was used as the benzothiazole vulcanization accelerator in the same manner as in Example A. still,
TMTD of Comparative Example 5 had the same molar amount as TEHT of Example 8. The ratio of MBTS / TEHT and MBTS / EH-Sb was changed. Also, as a rubber component, C1-IIR 50 parts by weight, EP
10 parts by weight of DM and 40 parts by weight of NR were used, and calcium carbonate was used as a filler.

[0034]

[Table 2]

As described above, when the ratio of MBTS / TEHT is less than 1.0, the modulus of elasticity is small, and the synergistic effect of mixing the vulcanization accelerator is difficult to appear. Further, the improvement in the strength at break is also slightly lower, and it is understood that this ratio is preferably 1.0 or more as the co-vulcanizability. Similarly, if the ratio of MBTS / TEHT is 5.
If it exceeds 0, the modulus of elasticity is small and the vulcanization rate is low, which is not preferable. The effect of improving the peel strength with different kinds of rubber (compounding in Table 5) is also small. When this ratio is in the range of 1.0 to 5.0, the vulcanization rate is high, processing stability is excellent,
It can be seen that a rubber excellent in co-vulcanization property, bending fatigue resistance and co-vulcanization property with different kinds of rubber can be obtained.

On the other hand, from Comparative Example 5, when TMTD out of the range of the present invention was used as a thiuram compound and a benzothiazole-based vulcanization accelerator was further blended, the compatibility of TMTD was poor and the blooming property was poor. It can be seen that they are inferior in co-vulcanization, bending fatigue resistance, and co-vulcanization with different types of rubber. Further, when these rubber compositions were used as white line rubber in the tire side portion, the co-vulcanizability with the adjacent rubber (sidewall rubber compounded in Table 6) was superior to that of the comparative example. It turns out that it is excellent in durability.

Example C (Examples 14 and 15, Comparative Examples 6 and 7) Similarly, Table 3 shows the mixing ratio (unit: parts by weight) of the rubber composition, the physical properties of the rubber composition, and the rubber composition. 4 shows the characteristics of a tire in which the product was used as a white line rubber in a tire side rubber portion. Example C is similar to Examples A and B,
In each example and each comparative example, the rubber component is 90 ≧ 2 × A + B
≧ 70 and C ≧ 20. In other words, the effect of the vulcanization accelerator specified by the present invention was confirmed for a rubber component having excellent weather resistance, and an example in which calcium carbonate was used as a filler and applied to white rubber as in Example B It is. In Example B, the proportion of the rubber component was calculated as follows:
They differ in that they are changed within a range satisfying the above two equations.

Further, using TEHT as a thiuram compound,
EH-Sb was used as the dithiocarbamate compound. MBTS was used as a benzothiazole vulcanization accelerator. As Comparative Example 6, an example using TMTD, which is a thiuram compound outside the scope of the present invention, was shown. Comparative Example 6
The TMTD of Example 14 had the same molar amount as the TEHT of Example 14.
In Comparative Example 7, TEHT was used alone as a vulcanization accelerator. The ratio of MBTS / TEHT and MBTS / EH-Sb is constant (3)
And

[0039]

[Table 3]

As described above, Examples 14 and 15 have higher breaking strength and peeling strength with different kinds of rubbers (compounds in Table 5) than those of Comparative Examples 6 and 7, and TEHT or EH in co-vulcanization.
It can be seen that a synergistic effect of -Sb and MBTS is exhibited. In addition, the modulus of elasticity is higher than when TEHT is used alone (Comparative Example 7), and a synergistic effect also appears on this surface. Further, when these rubber compositions were used in the white line on the tire side, the co-vulcanizability with the adjacent rubber (sidewall rubber in the composition shown in Table 6) was superior to that of the comparative example, and the durability as the tire side was high. It turns out that it is excellent.

Example D (Examples 16 and 17, Comparative Examples 8 and 9) Similarly, Table 4 shows the mixing ratio (unit: parts by weight) of the rubber composition and the physical properties of the rubber. In Example D, in Example 16 and Comparative Example 8, 40 parts by weight of C1-IIR as a rubber component, EPDM
In Example 17 and Comparative Example 9, 40 parts by weight of C1-IIR, 10 parts by weight of EPDM, and 50 parts by weight of NR were used as rubber components. That is, this is an example in which the value of (2 × A + B) exceeds 90 and less than 70, respectively.

In addition, TEHT was used as a thiuram compound. MBTS was used as a benzothiazole vulcanization accelerator. As Comparative Examples 8 and 9, examples using TMTD which is a thiuram compound outside the scope of the present invention were shown. The amounts of TMTD in Comparative Examples 8 and 9 were the same as the molar amount of TEHT in Examples 16 and 17.

[0043]

[Table 4]

As described above, Examples 16 and 17 are comparative examples 8 and
As compared with No. 9, the processing stability, the strength at break, the elastic modulus, the bending fatigue resistance, the peel strength with different types of rubber (compounding in Table 5) are larger,
Even in these polymers, TEHT and MB
It can be seen that a synergistic effect of TS appears. Also, it has excellent bloom resistance.

[Table 5]

[Table 6]

[0045]

As described above, according to the present invention,
By using a specific thiuram compound and / or a specific dithiocarbamate compound in combination with a benzothiazole vulcanization accelerator in a specific compounding ratio, the vulcanization rate, processing stability, blooming property, and co-vulcanization property are improved. When both are used as the side rubber, and a rubber composition that satisfies both requirements, it is possible to realize a tire having high strength and excellent in peel resistance at the interface between different types of rubber.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 23/28 C08L 23/28 // (C08K 5/00 5:39 5:47) (C08K 5/00 5:40 5: 47) B29K 23:00 (56) References JP-A-4-79906 (JP, A) JP-A-4-65273 (JP, A) JP-A-4-67218 (JP, A) JP-A-4-80847 (JP, A) JP-A-3-210346 (JP, A) JP-A-54-157148 (JP, A) JP-A-50-24344 (JP, A) JP-A-62-241943 (JP, A) 47-37260 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 B29D 30/72 B60C 1/00 C08K 5/00-5/59 C08L 7/00-21/02 CA (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] 1. A rubber component consisting of ethylene propylene rubber (hereinafter referred to as EPDM), a halogenated butyl rubber and a diene rubber, and 100 parts by weight of the rubber component are represented by the following formula: (Wherein R ₁ , R ₂ , R ₃ and R ₄ each independently represent a straight-chain or branched-chain alkyl group having 7 to 12 carbon atoms), and the following formula: 2] (Wherein, R ₅ and R ₆ each independently represent a straight-chain or branched-chain alkyl group having 7 to 12 carbon atoms, M is a divalent or higher-valent metal, and n is a valence of the metal of M. 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of dithiocarbamate compounds represented by the formula (1) and 0.5 to 3.0 parts by weight of a benzothiazole vulcanization accelerator. A rubber composition characterized by the following: 2. The benzothiazole vulcanization accelerator,
The rubber composition according to claim 1, wherein a ratio of a compound selected from the group consisting of the thiuram compound and the dithiocarbamate compound is 1.0 to 5.0. 3. The method according to claim ₂ , wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each a 2-ethylhexyl group, M is antimony, and n is 3. Item 1 or 2
The rubber composition as described in the above. 4. The rubber component according to claim 1, wherein 90.gtoreq.2.times.A + B.gtoreq.70 and C.gtoreq.20 (where A is the weight of EPDM, B is the weight of halogenated butyl rubber, C is the weight of diene rubber). The rubber composition according to any one of claims 1 to 3, which satisfies the following relationship: 5. A tire, wherein the rubber composition according to any one of claims 1 to 4 is used for a rubber on a side portion of the tire.