JP2010248423A - Rubber composition and tire using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition excellent in adhesion property with a metal such as a steel cord using a vulcanization accelerator having vulcanization delaying effect equal to or more than N,N-dicyclohexyl-2-benzothiazolylsulfenamide without using a vulcanization delaying agent having the possibility that problems such as reduction of a physical property of the rubber after vulcanization and blooming are generated. <P>SOLUTION: The rubber composition includes 0,3-10 pts.mass of sulfur and 0.1-10 pts.mass of a sulfenamide-based vulcanization accelerator represented by formula (I) based on 100 pts.mass of a rubber component. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rubber composition containing a specific sulfenamide-based vulcanization accelerator, in particular, using a specific sulfenamide-based vulcanization accelerator having a vulcanization retarding effect to lower the vulcanization physical properties. In addition, it is excellent in workability and has a rubber composition with significantly less rubber burns, a rubber composition with a highly suppressed heat generation, and a metal reinforcing material such as a steel cord used for rubber products such as tire industrial belts. The present invention relates to a rubber composition having excellent adhesion durability and a tire having excellent fuel efficiency and durability using a rubber composition having the above performance.

Conventionally, rubber products such as automobile tires, conveyor belts, hoses, etc., which require particularly high strength, are made of a rubber composition with a metal reinforcing material such as a steel cord for the purpose of reinforcing the rubber and improving the strength and durability. Coated composite materials are used.
In order for this rubber-metal composite material to exhibit a high reinforcing effect and obtain reliability, it is necessary to have a stable adhesion with little change with time between the rubber-metal reinforcing material. For this purpose, it is necessary to suppress heat generation of the rubber composition and ensure heat resistant adhesion.

  Further, when rubber and metal are bonded, a method of simultaneously bonding rubber and metal, that is, a direct vulcanization bonding method is known. In this case, vulcanization of rubber and bonding of rubber and metal are performed simultaneously. In view of the above, it is considered useful to use a sulfenamide-based vulcanization accelerator that gives a slow effect to the vulcanization reaction.

  Among the commercially available sulfenamide vulcanization accelerators, for example, N, N-dicyclohexyl-2-benzo represented by the following formula can be used as a vulcanization accelerator that most delays the vulcanization reaction. Thiazolylsulfenamide is known.

  In addition to the sulfenamide-based vulcanization accelerator, a vulcanization delay can be obtained if a delay effect is required in addition to the vulcanization reaction delay of the N, N-dicyclohexyl-2-benzothiazolylsulfenamide. A combination of agents is used. N- (cyclohexylthio) phthalimide is known as a typical vulcanization retarder that is commercially available. If a large amount of N- (cyclohexylthio) phthalimide is added to rubber, It has already been known that it causes blooming which adversely affects physical properties and adversely affects the appearance and adhesion of vulcanized rubber.

Furthermore, as a sulfenamide vulcanization accelerator other than the N, N-dicyclohexyl-2-benzothiazolylsulfenamide, for example, bissulfenamide represented by a specific formula (see Patent Document 1), A benzothiazolylsulfenamide-based vulcanization accelerator (see Patent Document 2) using an amine derived from natural fat as a raw material is known.
However, in these sulfenamide vulcanization accelerators described in Patent Documents 1 and 2, only the rubber physical properties are described, and there is no description or suggestion about the adhesion performance. Moreover, there is no description or suggestion that the sulfenamide compound of the present invention can be used as a novel vulcanization accelerator for rubber.

  Furthermore, some methods for producing sulfenamide compounds used in the present invention are known, for example, in Patent Documents 3, 4 and 5. These compounds are used as vulcanization accelerators for rubber. There is no description or suggestion about the ability to be newly used and the adhesion performance with the steel cord that this accelerator provides.

Furthermore, in recent years, demands for lower fuel consumption of automobiles are becoming increasingly severe in connection with the movement of global CO2 emission regulations due to social demands for energy conservation and increasing interest in environmental issues. . In order to meet such demands, reduction of rolling resistance has been demanded for tire performance. As a technique for reducing the rolling resistance of the tire, although a technique by optimizing the tire structure has been studied, the most common technique is to use a material having lower heat generation as the rubber composition.
In order to obtain such a rubber composition with low heat generation, technology development has been made so far to improve the dispersibility of the filler used in the rubber composition. Among them, as a rubber component, a method of modifying a polymerization active terminal of a diene polymer obtained by anionic polymerization using organolithium with a functional group interacting with a filler is becoming the most common. Yes (see, for example, Patent Document 6).
Further, at the stage of kneading the rubber composition, technical development for improving the dispersion of the filler has been carried out, and a method of kneading using a twin screw extruder has been proposed (for example, see Patent Document 7). However, there is no disclosure about the dispersion state of the reinforcing filler.
Among aggregates of reinforcing fillers in rubber compositions, those with a diameter of 10μφ or more have an adverse effect on wear resistance and fracture resistance, and therefore comply with the carbon dioxide emission regulations described above, further reducing tire rolling resistance. In order to achieve this, it is necessary to develop a rubber composition with low exothermic properties in which reinforcing fillers are highly dispersed.

JP 2005-139082 A JP 2005-139239 A EP0314663A1 publication British Patent No. 1177790 Japanese Patent Publication No. 48-11214 JP 2003-155302 A JP-A-5-154835

  The present inventor intends to solve this problem in view of the above-described conventional problems and the like, without using a vulcanization retarder that may cause problems such as deterioration of physical properties of rubber after vulcanization and blooming. Using a vulcanization accelerator having a retarding effect equivalent to or higher than that of N, N-dicyclohexyl-2-benzothiazolylsulfenamide, to provide a rubber composition with significantly less rubber burn, Providing a rubber composition having a highly suppressed property, and providing a rubber composition excellent in adhesion durability with a metal reinforcing material such as a steel cord used in rubber products such as tire industrial belts; and It aims at providing the tire excellent in the low fuel consumption and durability using the rubber composition which has the said performance.

    As a result of intensive studies on the above-described conventional problems, the present inventors use a specific sulfenamide-based vulcanization accelerator and realize a state in which the filler contained in the rubber component is highly dispersed. Thus, the inventors have found that the above rubber composition can be obtained, and that the effect of delaying vulcanization can be secured stably, and the present invention has been completed.

That is, the present invention
[1] A rubber component, a filler, sulfur, and a sulfenamide-based vulcanization accelerator represented by the following general formula (I) are included, and the dispersion state of the filler contained in the rubber component is In the dispersion evaluation method for observing the cut surface of the sample by the dark field method, the ratio of the area occupied by the filler agglomerates having an equivalent circle diameter of 10 μm or more to the entire observation visual field area is 2.0% or less. A rubber composition characterized by

[R ^{1 to} R ¹⁰ in Formula (I) are a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and these may be the same or different. Well, R ¹¹ is a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, R ^{12 to} R ¹⁵ are hydrogen atoms, and a linear alkyl group having 1 to 4 carbon atoms. Or it is an alkoxy group, a C3-C4 branched alkyl group, or an alkoxy group, and these may be the same or different. X represents an integer of 1 or 2. ]
[2] The rubber composition according to the above [1], comprising 0.1 to 10 parts by mass of the sulfenamide vulcanization accelerator represented by the general formula (I) with respect to 100 parts by mass of the rubber component.
[3] The rubber composition according to the above [1], comprising 0.3 to 10 parts by mass of sulfur with respect to 100 parts by mass of the rubber component;
[4] To 100 parts by mass of the rubber component, 0.3 to 10 parts by mass of sulfur and 0.1 to 10 parts by mass of the sulfenamide vulcanization accelerator represented by the above general formula (I) are contained. The rubber composition of [1] above,
[5] The rubber composition according to any one of the above [1] to [4], wherein the rubber component contains at least one of natural rubber and polyisoprene rubber.
[6] The rubber composition according to any one of the above [1] to [5], wherein the rubber component is 50% by mass or more of natural rubber and the balance is a diene synthetic rubber.
[7] The filler is carbon black, silica, and general formula (II)
nM · xSiO _y · zH ₂ O (II)
[Wherein M is at least selected from metals selected from aluminum, magnesium, titanium, calcium and zirconium, oxides or hydroxides of these metals, hydrates thereof, and carbonates of the metals. N, x, y, and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10. ]
A rubber composition according to any one of the above [1] to [4], comprising a filler comprising at least one selected from inorganic fillers represented by:
[8] The rubber composition according to any one of the above [1] to [7], further comprising cobalt and / or a compound containing cobalt.
[9] The rubber composition according to the above [8], wherein the content of cobalt and / or a compound containing cobalt is 0.03 to 3 parts by mass with respect to 100 parts by mass of the rubber component,
[10] The rubber composition according to [8] or [9] above, wherein the cobalt-containing compound is a cobalt salt of an organic acid, and [11] the rubber composition according to any one of [1] to [10] above. A tire characterized by that,
Is to provide.

  According to the present invention, among sulfenamide-based vulcanization accelerators, it is equivalent to N, N-dicyclohexyl-2-benzothiazolylsulfenamide known as a vulcanization accelerator that gives the slowest effect to the vulcanization reaction. It is a rubber composition containing a novel vulcanization accelerator suitable for rubber having the above vulcanization retarding effect, and can thereby increase the Mooney scorch time without deteriorating vulcanization properties. A rubber composition that is excellent in workability and tensile properties and that has much less rubber burns can be obtained. Further, the dispersion state of the filler contained in the rubber component is a dispersion evaluation method in which the cut surface of the sample is observed by the dark field method. When the proportion of the area occupied is 2.0% or less, it is possible to obtain a rubber composition excellent in heat resistance (low heat generation) by suppressing heat generation of the rubber composition, and at the same time stabilize Mooney scorch time. be able to.

Hereinafter, embodiments of the present invention will be described in detail.
The rubber composition of the present invention contains a rubber component, a filler, sulfur and a sulfenamide vulcanization accelerator represented by the following general formula (I), and is contained in the rubber component. In the dispersion evaluation method in which the dispersion state of the material observes the cut surface of the sample by the dark field method, the ratio of the area occupied by the filler aggregate having an equivalent circle diameter of 10 μm or more to the entire observation visual field area is 2.0. % Or less.

［式（Ｉ）中のＲ¹〜Ｒ¹⁵及びｘは上記で説明した通りである］

[R ^{1 to} R ¹⁵ and x in Formula (I) are as described above]

[Rubber component]
The rubber component used in the present invention is not particularly limited as long as it is a rubber used in rubber products such as tires and industrial belts, and sulfur crosslinking is possible if the rubber component has a double bond in the main chain. The sulfenamide vulcanization accelerator represented by the above general formula (I) functions, and for example, natural rubber and / or diene synthetic rubber is used. Specifically, at least one of natural rubber, polyisoprene rubber, styrene-butadiene copolymer, polybutadiene rubber, isoprene rubber, ethylene-propylene-diene copolymer, chloroprene rubber, halogenated butyl rubber, acrylonitrile-butadiene rubber and the like. Can be used.
Preferably, at least one of natural rubber and polyisoprene rubber is preferably included from the viewpoint of adhesiveness to a metal reinforcing material such as a steel cord. Further, from the viewpoint of durability of the belt rubber, the rubber component is preferably 50% by mass. The above natural rubber and the balance are preferably made of at least one synthetic rubber.

[Sulfenamide vulcanization accelerator]
The sulfenamide-based vulcanization accelerator represented by the above general formula (I) of the present invention has not been reported so far as being used as a vulcanization accelerator, and is used for the first time as a vulcanization accelerator in the present invention. N, N-dicyclohexyl-2-benzothiazolylsulfenamide known as a vulcanization accelerator that has the slowest effect on the vulcanization reaction among conventional sulfenamide vulcanization accelerators It has the above vulcanization delay effect and can be suitably used for rubber compositions for coating thick-walled rubber products, and is directly vulcanized and bonded to metal reinforcing materials such as steel cords. Excellent adhesion durability.

In the present invention, R ^{1 to} R ¹⁰ in the sulfenamide compound represented by the general formula (I) are a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms. Each may be the same or different. If R ^{1 to} R ¹⁰ are a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, the vulcanization acceleration performance of the compound represented by the general formula (I) is improved. It is good and can improve adhesive performance.
Specific examples of the straight-chain alkyl group or branched alkyl group having 1 to 4 carbon atoms in R ^{1 to} R ¹⁰ of the compound represented by the general formula (I) include a methyl group, an ethyl group, an n-propyl group, and isopropyl. Group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like. Among these, R ¹ , R ² , R ⁹ , and R ¹⁰ are hydrogen atoms, straight-chain alkyl groups having 1 to 4 carbon atoms, or 3 to 4 carbon atoms in view of the effect that a sufficiently long scorch time can be obtained. R ^{3 to} R ⁸ are preferably hydrogen atoms, and more preferably, R ¹ , R ² , R ⁹ , and R ¹⁰ are branched alkyl groups having 3 to 4 carbon atoms. desirable.

R ¹¹ in the sulfenamide compound represented by the general formula (I) represents a hydrogen atom, a straight chain having 1 to 10 carbon atoms, or a branched alkyl group having 3 to 10 carbon atoms. If this R ¹¹ is a straight chain having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, the vulcanization accelerating performance of the compound represented by the general formula (I) is good and the adhesion performance is improved. Can be increased.
Specific examples of R ¹¹ of the compound represented by the general formula (I) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl. Group, n-amyl group (n-pentyl group), isoamyl group (isopentyl group), neopentyl group, tert-amyl group (tert-pentyl group), n-hexyl group, isohexyl group, n-heptyl group, isoheptyl group, Examples thereof include an n-octyl group, an iso-octyl group, a nonyl group, an isononyl group, and a decyl group. Among these, from the viewpoint of effects such as ease of synthesis and raw material costs, a hydrogen atom, a straight chain having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms, and further a straight chain having 1 to 5 carbon atoms or A branched alkyl group having 3 to 5 carbon atoms is preferable, and in particular, a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group Is preferred.

R ^{12 to} R ¹⁵ in the sulfenamide compound represented by the general formula (I) are each a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or an alkoxy group, and a branched one having 3 to 4 carbon atoms. An alkyl group or an alkoxy group, which may be the same or different. Among them, R ¹² and R ¹⁴ are each a linear alkyl group or alkoxy group having 1 to 4 carbon atoms, or a group having 3 to 4 carbon atoms. A branched alkyl group or alkoxy group is preferred. Further, R ¹² to R ¹⁵ is preferably the alkyl group or alkoxy group having 1 to 4 carbon atoms is a 1 carbon atoms, and particularly preferably a hydrogen atom. This is because in any case, the ease of synthesis of the compound and the vulcanization rate do not slow down.
Specific examples of R ^{12 to} R ¹⁵ of the compound represented by the general formula (I) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, Examples thereof include a tert-butyl group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a tert-butoxy group.

Furthermore, x in the sulfenamide compound represented by the general formula (I) represents an integer of 1 or 2.
In addition, R ^{1 to} R ¹⁰ in the sulfenamide compound represented by the general formula (I) are each a functional group other than a hydrogen atom, a straight chain having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms. (E.g., n-octadecyl group) or a linear or branched alkyl group having more than 5 carbon atoms, and R ² is a hydrogen atom, a linear chain having 1 to 10 carbon atoms or a branched chain having 3 to 10 carbon atoms. In the case of each functional group other than an alkyl group (for example, n-octadecyl group) or a linear or branched alkyl group having more than 10 carbon atoms, the effects of the present invention are rarely exhibited, and Mooney scorch time As a result, the rubber is easily burnt and processability is deteriorated, adhesiveness is lowered, or vulcanization performance and rubber performance are sometimes lowered. Further, when x is 3 or more, it is not preferable in terms of stability.

In the present invention, typical examples of the compound represented by the general formula (I) include N-methylcyclohexyl-2-benzothiazolylsulfenamide, N-ethyl-N- (2,6-dimethylcyclohexene). Xyl) -2-benzothiazolylsulfenamide, N-ethyl-N- (2,6-diisopropylcyclohexyl) -2-benzothiazolylsulfenamide, and the like. These compounds can be used alone or in admixture of two or more (hereinafter, simply referred to as “at least one”).
Preferably, N-methylcyclohexyl-2-benzothiazolylsulfenamide, N-ethyl-N- (2,6-dimethylcyclohexyl) -2-benzothiazolylsulfene is used from the viewpoint of further adhesion performance. It is desirable to use an amide, N-ethyl-N- (2,6-diisopropylcyclohexyl) -2-benzothiazolylsulfenamide.
It can also be used in combination with general-purpose vulcanization accelerators such as N-tert-butyl-2-benzothiazolylsulfenamide, N-cyclohexyl-2-benzothiazolylsulfenamide, dibenzothiazolyl disulfide. Is possible.

[Method for producing sulfenamide compound]
The following method can be mentioned as a preferable manufacturing method of the sulfenamide compound represented by the general formula (I) of the present invention.
That is, N-chloroamine and bis (benzothiazolyl-2-yl) disulfide prepared in advance by the reaction of the corresponding amine and sodium hypochlorite are reacted in an appropriate solvent in the presence of an amine and a base. If an amine is used as the base, neutralize and return to the free amine, then subject to appropriate post-treatment such as filtration, washing with water, concentration and recrystallization according to the properties of the resulting reaction mixture. Sulfenamide is obtained.
Examples of the base used in this production method include raw material amine used in excess, tertiary amine such as triethylamine, alkali hydroxide, alkali carbonate, alkali bicarbonate, sodium alkoxide and the like. In particular, the reaction is carried out using excess raw material amine as a base or tertiary amine triethylamine, neutralizing the hydrochloride formed with sodium hydroxide, taking out the target product, and then removing the amine from the filtrate. A method of reuse is desirable.
As the solvent used in this production method, alcohol is desirable, and methanol is particularly desirable.

  For example, in N-methylcyclohexyl-2-benzothiazolylsulfenamide, an aqueous sodium hypochlorite solution is added dropwise to N-methylcyclohexylamine at 0 ° C. or lower, and after stirring for 2 hours, the oil layer is separated. Bis (benzothiazol-2-yl) disulfide, N-methylcyclohexylamine and the aforementioned oil layer are suspended in methanol and stirred under reflux for 2 hours. After cooling, it is neutralized with sodium hydroxide, filtered, washed with water, concentrated under reduced pressure, and then recrystallized to obtain the target compound.

The content of these sulfenamide-based vulcanization accelerators is 0.1 to 10 parts by mass, preferably 0.5 to 5.0 parts by mass, and more preferably 0.1 to 100 parts by mass of the rubber component. It is desirable to be 8 to 2.5 parts by mass.
When the content of the vulcanization accelerator is less than 0.1 parts by mass, the vulcanization is not sufficiently performed. On the other hand, when it exceeds 10 parts by mass, bloom is a problem, which is not preferable.

[Dispersed state of filler contained in rubber component]
In the present invention, the dispersion state of the filler contained in the rubber component is a dispersion evaluation method in which the cut surface of the sample is observed by the dark field method, and the filler having an equivalent circle diameter of 10 μm or more with respect to the entire observation field area The ratio of the area occupied by the aggregate is required to be 2.0% or less. Preferably it is 1.5%, More preferably, it is 1.0% or less.
By setting the filler to a highly dispersed state in the above range, heat generation of the rubber composition can be suppressed, and a rubber composition having low heat generation can be obtained.

[Production Method of Filler Highly Dispersed Rubber Composition]
In the dispersion evaluation method in which the state of dispersion of the filler contained in the rubber component observes the cut surface of the sample by the dark field method, the area occupied by the filler agglomerates having a circle equivalent diameter of 10 μm or more with respect to the entire observation visual field area There is no particular limitation on the method for producing the rubber composition having a ratio of 2.0% or less.For example, the method includes a step of mixing a slurry in which an inorganic filler containing carbon black is dispersed and a rubber latex. It can be obtained by a filler-containing rubber wet masterbatch. Alternatively, a batch type or continuous type rubber kneader may be used.
It can also be obtained by a dry masterbatch in which block-like natural rubber or synthetic rubber and a filler such as carbon black and silica are kneaded using the above apparatus, but the high dispersibility of the filler was obtained. A wet masterbatch is preferred from the viewpoint of the destructive properties of the composition.
A method for producing a filler-containing wet masterbatch (hereinafter sometimes simply referred to as a wet masterbatch) used in the present invention and a method for producing a rubber composition will be described in detail.
The wet masterbatch is formed by (a) the step of making the rubber compounding material liquid, (a ′) the step of mixing them, (a ″) the step of coagulating the mixed solution, (b) the step (a). And (c) a step of kneading and drying the coagulated product taken out in the step (b) using a first kneader and dispersing a filler, and (d) the step (c). It is preferable that the coagulated product dried in the step is further mixed with a rubber compounding material using a second kneader, wherein the above (a) to (c) are the rubber The filler composite preparation step, (d) is the mixing step.

-(A) Process-
This step is a step of making the rubber compounding material liquid.
Examples of the rubber liquid used in the step (a) include natural rubber latex and / or synthetic rubber latex, or an organic solvent solution of synthetic rubber obtained by solution polymerization. Natural rubber latex and / or synthetic rubber latex are preferred from the viewpoint of batch performance and ease of production.
As the natural rubber latex, any of field latex, ammonia-treated latex, centrifugal concentrated latex, deproteinized latex treated with an enzyme, and a combination of the above-mentioned ones can be used. Moreover, as synthetic rubber latex, latex, such as styrene-butadiene copolymer rubber, nitrile rubber, polychloroprene rubber, can be used, for example.

-(A ') process-
This step is a step of mixing the liquid rubber material obtained in the step (a).
In the method for producing the wet masterbatch, the rubber liquid contains carbon black, silica, and the following general formula (II):
nM · xSiO _y · zH ₂ O (II)
[Wherein M is at least selected from metals selected from aluminum, magnesium, titanium, calcium and zirconium, oxides or hydroxides of these metals, hydrates thereof, and carbonates of the metals. N, x, y, and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10. ]
The slurry liquid formed by disperse | distributing at least 1 type of filler chosen from the inorganic filler represented by this in a dispersion solvent using a high-speed shear mixer can be included.
Here, as carbon black, those usually used in the rubber industry can be used. For example, various grades of carbon black such as SAF, HAF, ISAF, FEF, and GPF can be used alone or in combination.
Silica is not particularly limited, but wet silica, dry silica, and colloidal silica are preferable. These can be used alone or in combination.

Specific examples of the inorganic filler represented by the general formula (II) include alumina (Al ₂ O ₃ ) such as γ-alumina and α-alumina, and alumina monohydrate (Al ₂ O such as boehmite and diaspore). ₃ · H ₂ O), Gibbsite, Bayerite, etc. Aluminum hydroxide [Al (OH) ₃ ], Aluminum carbonate [Al ₂ (CO ₃ ) ₂ ], Magnesium hydroxide [Mg (OH) ₂ ], Magnesium oxide ( MgO), magnesium carbonate (MgCO _3), talc _{(3MgO · 4SiO 2 · H 2} O), attapulgite _{(5MgO · 8SiO 2 · 9H 2} O), titanium white (TiO _2), titanium black (TiO _2n-1), calcium oxide (CaO), calcium hydroxide [Ca (OH) _2], magnesium aluminum oxide _{(MgO · Al 2 O 3)} , clay _{(Al 2 O 3 · 2SiO 2} ), Kao Down _{(Al 2 O 3 · 2SiO 2} · 2H 2 O), pyrophyllite _{(Al 2 O 3 · 4SiO 2} · H 2 O), bentonite _{(Al 2 O 3 · 4SiO 2} · 2H 2 O), aluminum silicate (Al ₂ SiO ₅ , Al ₄ · 3SiO ₄ · 5H ₂ O, etc.), magnesium silicate (Mg ₂ SiO ₄ , MgSiO ₃ etc.), calcium silicate (Ca ₂ · SiO ₄ etc.), aluminum calcium silicate (Al ₂ O ₃ · CaO · 2SiO ₂ etc.), magnesium calcium silicate (CaMgSiO ₄ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO (OH) ₂ · nH ₂ O], carbonic acid zirconium _{[Zr (CO 3) 2]} , crystalline aluminosilicate containing hydrogen, alkali metal or alkaline earth metal which corrects a charge as various zeolites There can be used.
The inorganic filler represented by the general formula (II) includes at least one selected from M selected from aluminum metal, aluminum oxide or hydroxide, hydrates thereof, and aluminum carbonate. preferable.

The high-speed shear mixer used for the preparation of the slurry liquid is a high-speed shear mixer composed of a rotor and a stator part, and a rotor that rotates at a high speed and a fixed stator are installed with a narrow clearance. Produces high shear rate. High-speed shearing means that the shear rate is 2000 / s or more, preferably 4000 / s or more.
Examples of commercially available high-speed shear mixers include a homomixer manufactured by Tokushu Kika Kogyo Co., Ltd., a colloid mill manufactured by PUC, a Cavitron manufactured by Cavitron, and a high shear mixer manufactured by Silverson UK.

The characteristics of the slurry liquid obtained using the high-speed shear mixer are as follows: (i) The particle size distribution of the filler in the slurry liquid is such that the volume average particle diameter (mv) is 25 μm or less, and 90 volume% particle diameter ( D90) is 30 μm or less, and (ii) the 24M4DBP oil absorption of the dry filler recovered from the slurry liquid is preferably maintained at 93% or more of the 24M4DBP oil absorption before being dispersed in the dispersion solvent. Here, the 24M4DBP oil absorption is a value measured according to ISO 6894.
More preferably, the volume average particle diameter (mv) is 20 μm or less, and the 90 volume% particle diameter (D90) is 25 μm or less. If the particle size is too large, the filler dispersion in the rubber may deteriorate, and the reinforcement and wear resistance may deteriorate.

On the other hand, if an excessive shearing force is applied to the slurry in order to reduce the particle size, the structure of the filler is destroyed and the reinforcing property is lowered. It is desirable that the 24M4DBP oil absorption amount of the filler recovered and dried from the slurry liquid is 93% or more of the 24M4DBP oil absorption amount of the filler before being dispersed in the dispersion solvent. More preferably, it is 96% or more.
In the slurry liquid, the concentration of the filler is preferably 1% by mass or more and 15% by mass or less, and more preferably 2% by mass or more and 10% by mass or less. By making the density | concentration of a filler into the said range, slurry volume and slurry viscosity can be made moderate and workability | operativity is improved.
In the present embodiment, the slurry liquid is preferably a water-dispersed slurry liquid, particularly from the viewpoint of mixing properties when natural rubber latex and / or synthetic rubber latex is used as the rubber liquid.

-(A ") Process-
This step is a step of coagulating the liquid mixture obtained in the mixing step.
The slurry liquid and the rubber liquid are mixed, for example, by adding the slurry liquid into a homomixer and dropping the latex while stirring, or conversely dropping the slurry liquid while stirring the latex. There is a way to do it. Also, a method of mixing a slurry flow having a constant flow rate and a latex flow under conditions of vigorous hydraulic stirring can be used.
In the step (a), a rubber liquid, preferably a rubber liquid containing the slurry liquid obtained as described above, is coagulated to form a solidified product. This coagulation method is performed by a conventionally known method, for example, by applying a shearing force such as an acid such as formic acid or sulfuric acid, a salt coagulant such as sodium chloride, heat or stirring. Moreover, you may combine the said some means.

-(B) process and (c) process-
The step (b) is a step of taking out the solidified product formed in the step (a) using a conventionally known solid-liquid separation means and washing it sufficiently. For washing, a water washing method is usually adopted.
The step (c) is a step in which the coagulated product taken out in the step (b) and sufficiently washed is kneaded and dried using a first kneader while applying mechanical shearing force, and the filler is dispersed. is there.
In the step (c), since it is kneaded and dried while applying mechanical shearing force using the first kneader, it is preferable to operate continuously from the viewpoint of industrial productivity. Although an apparatus equipped with a single screw can be used, it is more preferable to use a multi-screw kneading extruder that rotates in the same direction or in different directions, and it is particularly preferable to use a twin-screw kneading extruder.
By the above production method, a master batch in which the filler is highly dispersed in the rubber component can be obtained. A combination of natural rubber as the rubber component and carbon black or silica as the filler is preferable, and a combination of natural rubber as the rubber component and carbon black as the filler is particularly preferable from the viewpoint of industrial productivity.

-(D) Process-
Step (d) is a step in which a compounded material for rubber is further mixed with the dried wet masterbatch obtained in step (c) using a second kneader to obtain a compounded batch containing a compounded material for rubber. . Here, the dried state means that the moisture content is sufficiently low. Specifically, it means a state where the volatile content in the rubber is 5% by mass or less, preferably 3% by mass or less. The measurement method was performed according to JIS K6238.
The second kneader is any one selected from a meshing internal mixer in which two rotors mesh with each other (hereinafter also referred to as a meshing Banbury mixer), a tangential Banbury mixer, an open roll, and a kneader. Preferably there is.

Among them, it is preferable to use a batch kneader such as a tangential or meshing Banbury mixer as the second kneader.
In general, continuous kneaders (continuous kneaders) represented by twin screw extrusion kneaders are blended per unit volume compared to batch kneaders (batch kneaders) represented by Banbury mixers. A batch-type kneader such as a Banbury mixer is preferred in order to uniformly disperse rubber chemicals having a large amount of variation and a small blending amount in the rubber composition.

As mentioned above, although the manufacturing method by a wet masterbatch was described in detail, the rubber composition with which the dispersion state of the said filler satisfy | fills the above-mentioned relationship can be obtained also by a dry masterbatch.
A dry masterbatch containing a rubber component and a filler can be usually obtained by kneading a block-like natural rubber or synthetic rubber with a filler such as carbon black or silica. A typical kneading machine (first kneading machine) includes a tangential (non-meshing) internal mixer (hereinafter sometimes referred to as a tangential Banbury mixer) or a twin-screw kneading extruder. A tangential Banbury mixer with good rubber biting is preferred.
The dry masterbatch in which the filler is highly dispersed can be obtained, for example, by kneading natural rubber or synthetic rubber with a filler such as carbon black or silica, cooling, and then repeating the plasticizing kneading process several times. .

The rubber composition used in the present invention is obtained by blending the carbon black-containing wet masterbatch or dry masterbatch obtained by the above method. In addition to the rubber component, sulfur, filler, vulcanization accelerator and cobalt compound, the rubber composition includes a vulcanizing agent, a vulcanization accelerator, zinc white, stearin as long as the object of the present invention is not impaired. Various chemicals usually used in the rubber industry such as acid can be added.
Moreover, in this rubber composition, it is preferable that the rubber component (natural rubber) by the said wet masterbatch is included 50 mass parts or more with respect to the whole rubber component (100 mass parts). Examples of the remaining rubber component used in addition to the wet masterbatch include ordinary natural rubber and diene synthetic rubber. Examples of the diene synthetic rubber include styrene-butadiene copolymer (SBR), polybutadiene ( BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, and mixtures thereof.

[sulfur]
Sulfur used in the present invention serves as a vulcanizing agent, and the content thereof is 0.3 to 10 parts by mass, preferably 1.0 to 7.0 parts by mass, with respect to 100 parts by mass of the rubber component. More preferably, it is desirable to set it as 3.0-7.0 mass parts.
If the sulfur content is less than 0.3 parts by mass, vulcanization will not be achieved sufficiently. On the other hand, if it exceeds 10 parts by mass, the aging performance of the rubber will be unfavorable.

[Cobalt (single) and / or cobalt-containing compound]
Furthermore, it is preferable that the rubber composition of the present invention contains cobalt (a simple substance) and / or a compound containing cobalt from the viewpoint of improving the initial adhesion performance.
Examples of the cobalt-containing compound that can be used include at least one of a cobalt salt of an organic acid and a cobalt salt of an inorganic acid, such as cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt phosphate, and cobalt chromate.
Preferably, it is desirable to use a cobalt salt of an organic acid from the viewpoint of further improving the initial adhesion performance.
Examples of the organic acid cobalt salt that can be used include at least one of cobalt naphthenate, cobalt stearate, cobalt neodecanoate, cobalt rosinate, cobalt versatate, cobalt tall oil, and the like. The organic acid cobalt may be a complex salt in which a part of the organic acid is replaced with boric acid. Specifically, a commercial name “manobond” manufactured by OMG Co., Ltd. may be used.
The (total) content of these cobalt and / or cobalt-containing compounds is 0.03 to 3 parts by mass, preferably 0.03 to 1 part by mass, with respect to 100 parts by mass of the rubber component, as the amount of cobalt. More preferably, it is desirable to set it as 0.05-0.7 mass part.
If the content of these cobalt amounts is less than 0.03 parts by mass, further adhesiveness cannot be exhibited. On the other hand, if it exceeds 3 parts by mass, the aging resistance is greatly lowered, which is not preferable.

The rubber composition of the present invention can be produced by kneading the above components with, for example, a Banbury mixer, a kneader or the like. Tire treads for passenger cars, trucks, buses, motorcycles, etc., hoses, belt conveyors It can be suitable for thick rubber products.
Further, the rubber composition of the present invention containing a cobalt compound is a rubber product that requires particularly high strength, such as automobile tires, conveyor belts, hoses, and the like. Specifically, the rubber is reinforced to improve strength and durability. For the purpose, it can be suitably applied to a rubber-metal composite material in which a metal reinforcing material such as a steel cord is coated with a rubber composition.

In the rubber composition of the present invention configured as described above, among the sulfenamide-based vulcanization accelerators, N, N-dicyclohexyl-2-known as a vulcanization accelerator that gives the slowest effect to the vulcanization reaction. Contains a novel vulcanization accelerator that has a vulcanization retarding effect equivalent to or better than that of benzothiazolylsulfenamide, so it uses a vulcanization retarder that may cause problems such as deterioration in physical properties and blooming of vulcanized rubber. Without using the specific sulfenamide-based vulcanization accelerator having a vulcanization delay effect, the Mooney scorch time can be stably obtained without deteriorating the vulcanization physical properties. A rubber composition that is excellent and has a rubber rubber burn rate that is remarkably less likely to be obtained, and a rubber composition that further contains cobalt (a simple substance) and / or a compound containing cobalt. Further, the rubber composition excellent in adhesion durability with metal reinforcing materials such as steel cords used for rubber products such as tires and industrial belts is obtained.
Further, the dispersion state of the filler contained in the rubber component is a dispersion evaluation method in which the cut surface of the sample is observed by the dark field method. By using a carbon black-containing natural rubber wet masterbatch with an area ratio of 2.0% or less, a rubber composition excellent in heat resistance (low heat generation) and a Mooney scorch time can be stably obtained. I was able to.

  Next, the production examples of the vulcanization accelerator of the present invention and the examples and comparative examples of the rubber composition of the present invention will be described in more detail. The present invention is not limited to these production examples and examples. It is not limited.

[Synthesis Example 1: Synthesis of N-methylcyclohexyl-2-benzothiazolylsulfenamide]
To 18.3 g (0.162 mol) of N-methylcyclohexylamine, 148 g of a 12% sodium hypochlorite aqueous solution was added dropwise at 0 ° C. or lower, and after stirring for 2 hours, the oil layer was separated. Bis (benzothiazol-2-yl) disulfide (39.8 g, 0.120 mol), N-methylcyclohexylamine (27.1 g, 0.240 mmol) and the oil layer described above were suspended in 120 ml of methanol and refluxed. Stir for 2 hours. After cooling, the solution is neutralized with 6.6 g (0.166 mol) of sodium hydroxide, filtered, washed with water, concentrated under reduced pressure, and recrystallized to obtain the desired N-methylcyclohexyl-2-benzothiazolylsulfenamide. Was obtained as a white solid.

[Synthesis Example 2: Synthesis of N-ethyl-N- (2,6-dimethylcyclohexyl) -2-benzothiazolylsulfenamide]
The same procedure as in Example 1 was carried out using 25.1 g (0.162 mol) of N-dimethylcyclohexylethylamine instead of N-methylcyclohexylamine, and N-ethyl-N- (2,6-dimethylcyclohexyl)- 2-Benzothiazolylsulfenamide was obtained as a white solid.

[Synthesis Example 3: Synthesis of N-ethyl-N- (2,6-diisopropylcyclohexyl) -2-benzothiazolylsulfenamide]
The same procedure as in Example 1 was carried out using 34.2 g (0.162 mol) of N-diisopropylcyclohexylethylamine instead of N-methylcyclohexylamine, and N-ethyl-N- (2,6-diisopropylcyclohexyl)- 2-Benzothiazolylsulfenamide was obtained as a white solid.

Production Example 1 Manufacture of wet masterbatch [MB1] (1) Preparation of carbon black slurry 45 parts by mass of carbon black (N220) is added to 955 parts by mass of water in terms of dryness, and rotated at 4800 rpm with a high shear mixer manufactured by Silverson. Slurry treatment was performed at a speed for 30 minutes to produce a carbon black-containing slurry.
Carbon black (N220) before dispersion had a 24M4DBP oil absorption of 98 mL / 100 g, and CB recovered from the slurry and dried had a 24M4DBP oil absorption of 94 mL / 100 g. The 24M4DBP oil absorption is measured in accordance with ISO 6894.
(2) Manufacture of wet masterbatch After mixing the carbon black containing slurry whole quantity obtained by said (1), and 1000 mass parts of natural rubber concentration latex containing ammonia diluted to 10 mass%, it mixed with this. Formic acid was added to adjust the pH to 4.7 and coagulated. Next, the coagulated product is washed with water, filtered through a non-woven fabric, dehydrated, and then introduced into a twin-screw continuous kneader “KTX-30” manufactured by Kobe Steel Co., Ltd. so that the discharge temperature becomes 150 ° C. and mechanical shear force By processing continuously while applying, the filler was highly dispersed and dried to obtain a natural rubber-carbon black wet masterbatch [MB1]. In this master batch, the amount of carbon black per 100 parts by mass of natural rubber was 45 parts by mass.

Production Example 2 Carbon black (N220) was added to 955 parts by mass of production water of wet masterbatch [MB2], 45 parts by mass in dry conversion, and 600 parts by mass of natural rubber concentrated latex containing ammonia diluted to 10% by mass was used. The same treatment as in Production Example 1 was performed to obtain a natural rubber-carbon black wet masterbatch [MB2]. In this master batch, the amount of carbon black per 100 parts by mass of natural rubber was about 75 parts by mass. However, as shown in Table 1, in evaluating the characteristic values, by dry blending 40 parts by mass of butadiene rubber with respect to 105 parts by mass of the wet masterbatch [MB2], 100 parts by mass of the rubber component and 45 parts by mass of carbon black. The part.

Production Example 3 Manufacture of wet masterbatch [MB3] Natural rubber-carbon black wet masterbatch [Natural rubber-carbon black wet masterbatch] was performed except that 60 parts by mass of carbon black (N330) was added to 955 parts by mass of water in dry conversion. MB3] was obtained. In this master batch, the amount of carbon black per 100 parts by mass of natural rubber was about 60 parts by mass.
The 24M4DBP oil absorption of carbon black (N330) before dispersion was 88 mL / 100 g, and the 24M4DBP oil absorption of CB recovered from the slurry and dried was 83 mL / 100 g.

Production Example 4 Manufacture of dry masterbatch [DMB] 100 parts by weight of natural rubber, 45 parts by weight of carbon black, anti-aging agent, stearic acid, and wax each with a composition of 1 part by weight using a 2200 ml Banbury mixer, After cooling the mixed composition, 4 times of plasticizing kneading were added using the same Banbury mixer to obtain a dry masterbatch [DMB]. In addition, the process which cools the composition plasticized and kneaded between plasticization kneading | mixing at room temperature was provided.
The obtained master batch was used in Example 4 of Table 1.

[Examples 1-8 and Comparative Examples 1-12]
Using 2200 ml Banbury mixer, rubber component, sulfur, three wet masterbatch and one dry masterbatch obtained in the above production example, vulcanization accelerator obtained in the above synthesis example, organic acid cobalt salt The other compounding agents were kneaded and mixed in the formulation shown in Tables 1 and 2 below to prepare an unvulcanized rubber composition, and Mooney viscosity, Mooney scorch time, and Mooney scorch time stability were as follows. The tensile stress (M300) at 300% elongation, the dispersion state of the filler, the heat generation property and the heat-resistant adhesion performance were evaluated by the following methods.
These results are shown in Tables 1 and 2 below.

(Evaluation method for Mooney viscosity and Mooney scorch time)
This was performed according to JIS K 6300-1: 2001.
The evaluation was expressed as an index with the value of Comparative Example 1 being 100. The smaller the value of Mooney viscosity, the better the workability, and the greater the Mooney scorch time, the better the workability.

(Mooney coach time stability)
The coefficient of variation when the Mooney scorch time was measured 6 times was indexed. The smaller the value, the more stable it is.

(Stress of 300% elongation)
A vulcanized rubber obtained by vulcanizing the above rubber composition at 145 ° C. for 60 minutes is subjected to a measurement test at 25 ° C. in accordance with JIS K 6301-1995 (No. 3 type test piece) and stretched by 300%. The tensile stress at the time (M300) was measured, and the tensile stress of the rubber composition of Comparative Example 1 was taken as 100 and indicated as an index. Larger values indicate better tensile properties.

(Evaluation of filler dispersion state)
Based on ISO11345, evaluation is made based on the ratio of 10 μm or more of the observation visual field calculated from the frequency distribution of the equivalent circle diameter of the carbon black aggregate obtained from the despa grader.

(Evaluation of heat generation)
Measured at room temperature (25 ° C.) in accordance with JIS K 6255: 1996 trypso-type rebound resilience test method, and the values of Comparative Example 1, Comparative Example 8 and Comparative Example 10 were each expressed as an index. Larger values indicate greater impact resilience and lower heat build-up.

[Adhesion test method]
Three steel cords (outer diameter 0.5 mm x length 300 mm) plated with brass (Cu: 63 wt%, Zu: 37 wt%) are arranged in parallel at 10 mm intervals, and this steel cord is coated with each rubber composition from both the upper and lower sides. This was vulcanized at 160 ° C. for 20 minutes to prepare a sample.
About the adhesiveness of each obtained sample, according to ASTM-D-2229, the steel cord was pulled out from each sample, the covering state of the rubber was visually observed, and displayed in 0 to 100%. It was used as an index. The heat-resistant adhesion is indicated by 0-100% after each ampoule is left in a gear oven at 100 ° C. for 15 days for 30 days, and then the steel cord is pulled out by the above test method and the rubber coating state is visually observed. And used as an index for each thermal adhesiveness. It shows that it is excellent in heat-resistant adhesiveness, so that a numerical value is large.

［注］
＊１：ブタジエンゴム（ＪＳＲ社製、商品名：ＢＲ０１）
＊２：Ｎ，Ｎ’−ジシクロヘキシル−２−ベンチアゾリルスルフェンアミド（大内新興化 学工業製、商品名：ノクセラーＤＺ）
＊３：Ｎ−シクロヘキシル−２−ベンチアゾリルスルフェンアミド（大内新興化学工業製 、商品名：ノクセラーＣＺ）
＊４：Ｎ−ｔ-ブチルベンゾチアゾリル−２−スルフェンアミド（大内新興化学工業製、 商品名：ノクセラーＮＳ）
＊５：Ｎ−メチルシクロへキシル−２−ベンゾチアゾリルスルフェンアミド（合成例１で 得られた物を用いた）

＊６：Ｎ−エチル−Ｎ−（２，６−ジメチルシクロへキシル）−２−ベンゾチアゾリルス ルフェンアミド（合成例２で得られた物を用いた）

＊７：Ｎ−エチル−Ｎ−（２，６−ジイソプロピルシクロへキシル）−２−ベンゾチアゾ リルスルフェンアミド（合成例３で得られた物を用いた）

[note]
* 1: Butadiene rubber (JSR, trade name: BR01)
* 2: N, N′-dicyclohexyl-2-benchazolylsulfenamide (Ouchi Shinsei Kagaku Kogyo, trade name: Noxeller DZ)
* 3: N-cyclohexyl-2-benchazolylsulfenamide (Ouchi Shinsei Chemical Co., Ltd., trade name: Noxeller CZ)
* 4: Nt-Butylbenzothiazolyl-2-sulfenamide (Ouchi Shinsei Chemical Co., Ltd., trade name: Noxeller NS)
* 5: N-methylcyclohexyl-2-benzothiazolylsulfenamide (using the product obtained in Synthesis Example 1)

* 6: N-ethyl-N- (2,6-dimethylcyclohexyl) -2-benzothiazolylsulfenamide (the product obtained in Synthesis Example 2 was used)

* 7: N-ethyl-N- (2,6-diisopropylcyclohexyl) -2-benzothiazolylsulfenamide (the product obtained in Synthesis Example 3 was used)

［注］
＊１１；ＯＭＧ社製、商品名：コバルトマノボンドＣ２２．５、コバルト含有量２２．５質量％

[note]
* 11: Product name: Cobalt Manobond C22.5, cobalt content 22.5% by mass, manufactured by OMG

As is clear from the results of Table 1 above, Examples 1 to 5, which are the scope of the present invention, are not reduced in vulcanized physical properties (M300) as compared with Comparative Examples 1 to 9 which are outside the scope of the present invention. Since the Mooney scouring time can be extended, the workability is excellent and the scorch stability is also good.
Further, by using the sulfenamide vulcanization accelerator of the present invention as a vulcanization accelerator and combining with a rubber composition in which a filler is highly dispersed, the rubber of the present invention is compared with the rubber composition of the comparative example. It can be seen that the composition is significantly less exothermic.
Furthermore, the scorch stability is good.
The above Table 2 is a compounding prescription of each rubber composition further containing a cobalt-containing compound and the like. As is apparent from the results of Table 2, Examples 6 to 8 within the scope of the present invention are the present invention. Compared with Comparative Examples 10 to 12 outside the range, the Mooney coat time can be extended without deteriorating the vulcanization physical properties (M300), so that the workability and the tensile properties are excellent, and the low exothermic property is achieved. It has been found that it exhibits excellent and even better heat-resistant adhesiveness.

  In the rubber composition of the present invention, tire treads for passenger cars, trucks, buses, motorcycles, etc., under treads, sidewalls, carcass coating rubbers, belt coating rubbers, bead filler rubbers, chafers, bead coating rubbers, cushion rubbers, The present invention can be suitably applied to thick rubber products such as hoses and belt conveyors, and rubber products in which rubber and metal are directly vulcanized and bonded.

Claims (11)

The dispersion state of the filler contained in the rubber component comprising a rubber component, a filler, sulfur and a sulfenamide vulcanization accelerator represented by the following general formula (I) is dark field In the dispersion evaluation method for observing the cut surface of the sample by the method, the ratio of the area occupied by the filler aggregate having an equivalent circle diameter of 10 μm or more to the total observation visual field area is 2.0% or less. Rubber composition.

[R ^{1 to} R ¹⁰ in Formula (I) are a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, or a branched alkyl group having 3 to 4 carbon atoms, and these may be the same or different. Well, R ¹¹ is a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, R ^{12 to} R ¹⁵ are hydrogen atoms, and a linear alkyl group having 1 to 4 carbon atoms. Or it is an alkoxyl group, a C3-C4 branched alkyl group, or an alkoxy group, and these may be the same or different. X represents an integer of 1 or 2. ]   The rubber composition according to claim 1, comprising 0.1 to 10 parts by mass of the sulfenamide vulcanization accelerator represented by the general formula (I) with respect to 100 parts by mass of the rubber component.   The rubber composition according to claim 1, comprising 0.3 to 10 parts by mass of sulfur with respect to 100 parts by mass of the rubber component.   Claims comprising 0.3 to 10 parts by mass of sulfur and 0.1 to 10 parts by mass of the sulfenamide vulcanization accelerator represented by the above general formula (I) with respect to 100 parts by mass of the rubber component. Item 2. The rubber composition according to Item 1.   The rubber composition according to any one of claims 1 to 4, wherein the rubber component contains at least one of natural rubber and polyisoprene rubber.   The rubber composition according to any one of claims 1 to 5, wherein the rubber component comprises 50% by mass or more of natural rubber and the balance is a diene synthetic rubber. Filler is carbon black, silica and general formula (II)
nM · xSiO _y · zH ₂ O (II)
[Wherein M is at least selected from metals selected from aluminum, magnesium, titanium, calcium and zirconium, oxides or hydroxides of these metals, hydrates thereof, and carbonates of the metals. N, x, y, and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10. ]
The rubber composition in any one of Claims 1-4 containing the filler which consists of at least 1 type chosen from the inorganic filler represented by these.   Furthermore, the rubber composition in any one of Claims 1-7 containing the compound containing cobalt and / or cobalt.   The rubber composition according to claim 8, wherein the content of cobalt and / or a compound containing cobalt is 0.03 to 3 parts by mass with respect to 100 parts by mass of the rubber component as the amount of cobalt.   The rubber composition according to claim 8 or 9, wherein the cobalt-containing compound is a cobalt salt of an organic acid.   A tire using the rubber composition according to claim 1.