JP2021080337A - Rubber composition and tire - Google Patents

Abstract

To provide a tire improved in balance of crack resistance, weather resistance and fuel economy, and a rubber composition capable of producing the same.SOLUTION: The rubber composition contains a rubber component containing: a nonconjugated diene compound-nonconjugated olefin copolymer (A) containing an ethylene-propylene-diene rubber; and a copolymer (B) containing a conjugated diene unit, a nonconjugated olefin unit, and an aromatic vinyl unit. The content of the nonconjugated diene compound-nonconjugated olefin copolymer (A) in the rubber component is 28 mass% or more.SELECTED DRAWING: None

Description

The present invention relates to rubber compositions and tires.

A conjugated diene compound-non-conjugated olefin copolymer (A) having a content of a conjugated diene compound-derived moiety of 40 mol% or more for the purpose of producing a rubber having excellent weather resistance, fracture resistance and crack growth resistance. It is known to use a rubber composition containing a conjugated diene polymer (B) and a non-conjugated diene compound-non-conjugated olefin copolymer (C) containing an ethylene-propylene-diene rubber (for example). , Patent Document 1).

International Publication No. 2012/117715

However, there is a need to improve the balance of characteristics at a higher level.
An object of the present invention is to provide a tire having an improved balance of crack resistance, weather resistance, and fuel efficiency, and a rubber composition capable of producing the same, and it is an object of the present invention to solve the object. ..

<1> A non-conjugated diene compound-non-conjugated olefin copolymer (A) containing an ethylene-propylene-diene rubber, and a copolymer (B) containing a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit. A rubber composition containing a rubber component containing and, wherein the content of the non-conjugated diene compound-non-conjugated olefin copolymer (A) in the rubber component is 28% by mass or more.

<2> The rubber composition according to <1>, wherein the content of the antiaging agent is less than 1% by mass.
<3> The copolymer (B) has a conjugated diene unit content of 16 to 55 mol%, a non-conjugated olefin unit content of 40 to 80 mol%, and an aromatic vinyl unit content. The rubber composition according to <1> or <2>, wherein the amount is 1 to 15 mol%.
<4> The rubber composition according to any one of <1> to <3>, wherein the content of the non-conjugated diene compound-non-conjugated olefin copolymer (A) in the rubber component is less than 90% by mass. Stuff.

<5> The rubber composition according to any one of <1> to <4>, wherein the copolymer (B) has a polystyrene-equivalent weight average molecular weight of 250,000 to 650,000.
<6> The rubber composition according to any one of <1> to <5>, wherein the copolymer (B) is a non-conjugated olefin unit in which the non-conjugated olefin unit is acyclic.
<7> The rubber composition according to <6>, wherein the copolymer (B) is composed of only ethylene units as the acyclic non-conjugated olefin unit.
<8> The rubber composition according to any one of <1> to <7>, wherein the copolymer (B) contains a styrene unit in the aromatic vinyl unit.
<9> The copolymer (B) is any one of <1> to <8>, wherein the conjugated diene unit contains at least one selected from the group consisting of 1,3-butadiene units and isoprene units. The rubber composition according to.

<10> A tire using the rubber composition according to any one of <1> to <9>.

According to the present invention, it is possible to provide a tire having an improved balance of crack resistance, weather resistance, and fuel efficiency, and a rubber composition capable of producing the tire.

<Rubber composition>
The rubber composition of the present invention is a copolymer containing a non-conjugated diene compound-non-conjugated olefin copolymer (A) containing an ethylene-propylene-diene rubber, a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit. It contains a rubber component containing the polymer (B), and the content of the non-conjugated diene compound-non-conjugated olefin copolymer (A) in the rubber component is 28% by mass or more.
The rubber composition may further contain components such as a filler, a softener, and a cross-linking agent.
Hereinafter, the non-conjugated diene compound-non-conjugated olefin copolymer (A) containing ethylene-propylene-diene rubber may be simply referred to as a copolymer (A). Further, the copolymer (B) containing a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit may be simply referred to as a copolymer (B).

As shown in Patent Document 1, it contains a conjugated diene compound-non-conjugated olefin copolymer, a conjugated diene-based polymer, and an ethylene-propylene-diene rubber having a content derived from the conjugated diene compound of 40 mol% or more. By mixing a non-conjugated diene compound with a non-conjugated olefin copolymer, a vulture rubber having excellent weather resistance, fracture resistance and crack growth resistance can be obtained. However, in addition to weather resistance, tires with higher crack resistance and low fuel consumption are also required by the industry.
By using the copolymer (B) instead of the conjugated diene compound-non-conjugated olefin copolymer and the conjugated diene-based polymer in which the content of the portion derived from the conjugated diene compound is 40 mol% or more, the content is high in the vulture rubber. Although mechanical strength can be achieved, there is a risk that weather resistance will decrease.

On the other hand, the rubber composition of the present invention does not lower the weather resistance of the vulcanized rubber by setting the content of the copolymer (A) of the present invention to 28% by mass or more in the rubber component, and also. It is considered that the inclusion of the copolymer (B) provides not only excellent mechanical strength but also low fuel consumption. More specifically, when the copolymer (B) contains a non-conjugated olefin unit together with a conjugated diene unit and an aromatic vinyl unit, crystals derived from the non-conjugated olefin unit when the vulcanized rubber is greatly distorted. It is considered that the copolymer (B) can dissipate the energy due to the decay of the components and the melting energy. Further, unlike the ethylene-butadiene copolymer (EBR), the crystal component derived from the non-conjugated olefin unit is small and finely dispersed in the rubber composition, so that even vulcanized rubber has low strain due to crystal binding. It is considered that the loss in ethylene is suppressed and the fuel efficiency of the tire is improved. As a result, the vulcanized rubber can have high crack resistance and excellent fuel efficiency, and in total, the vulcanized rubber obtained from the rubber composition of the present invention has been previously used as a vulcanized rubber. In comparison, it is considered that the balance between crack resistance, weather resistance, and fuel efficiency is improved.
The details of the rubber composition and the tire of the present invention will be described below.

[Copolymer (A)]
The rubber composition of the present invention contains a non-conjugated diene compound-non-conjugated olefin copolymer (A) containing ethylene-propylene-diene rubber (EPDM), and the content of the copolymer (A) is a rubber component. Medium 28% by mass or more.
If the content of the copolymer (A) in the rubber component is less than 28% by mass, the vulcanized rubber cannot exhibit excellent weather resistance.
The copolymer (A) is a copolymer of a non-conjugated diene compound and a non-conjugated olefin, and contains a non-conjugated olefin as a monomer unit component in the copolymer. The diene content of the copolymer (A) is preferably 10% or less.

For EPDM contained in the copolymer (A), a small amount of a third component was introduced into ethylene propylene rubber (EPM), which is a copolymer of ethylene and propylene, to have a double bond in the main chain. Has a structure. There are various synthetic rubbers depending on the type and amount of the third component, and typical third components are ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), and dicyclopentadiene (dicyclopentadiene). DCP) and the like. EPDM is excellent in aging resistance, cold resistance, solvent resistance, etc. in addition to weather resistance.

The content of EPDM in the copolymer (A) is preferably 10% by mass or more, more preferably 40% by mass or more, from the viewpoint of further improving the weather resistance of the vulcanized rubber. It is more preferably 70% by mass or more, and may be 100% by mass.

In the copolymer (A), the non-conjugated olefin used as a monomer is a non-conjugated olefin other than the conjugated diene compound, and brings excellent heat resistance to the copolymer (A). Further, since the copolymer (A) contains a non-conjugated olefin, the ratio of double bonds in the main chain of the copolymer can be reduced, the crystallinity can be lowered, and the degree of design freedom as an elastomer can be increased. It will be possible.
The non-conjugated olefin is preferably an acyclic olefin, and the non-conjugated olefin preferably has 2 to 10 carbon atoms. Therefore, as the non-conjugated olefin, α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene are preferably mentioned, and among these, ethylene and propylene are preferable. And 1-butene are preferred, and ethylene is particularly preferred. Since the α-olefin has a double bond at the α-position of the olefin, copolymerization with a conjugated diene can be efficiently performed. These non-conjugated olefins may be used alone or in combination of two or more. The olefin is an aliphatic unsaturated hydrocarbon and refers to a compound having one or more carbon-carbon double bonds. Further, when a block portion made of a monomer unit of a non-conjugated olefin is provided, it exhibits static crystallinity, so that it can be excellent in mechanical properties such as breaking strength.
In addition, acyclic means that it is linear or branched.

Examples of the non-conjugated diene compound used as a monomer in the copolymer (A) include ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), dicyclopentadiene (DCP), and the like. Ethylidene norbornene (ENB) is preferred.

The content of the copolymer (A) in the rubber component is preferably 30% by mass or more, more preferably 35% by mass or more, from the viewpoint of further improving the weather resistance of the vulcanized rubber. Further, from the viewpoint of the balance between crack resistance, weather resistance and fuel efficiency of the vulcanized rubber, the content of the copolymer (A) in the rubber component is preferably less than 90% by mass, preferably 85% by mass. It is more preferably less than%, and even more preferably less than 80% by mass.

[Copolymer (B)]
The rubber composition of the present invention contains a copolymer (B) containing a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit as a rubber component.
If the rubber composition of the present invention does not contain the copolymer (B), the vulcanized rubber cannot exhibit crack resistance and low fuel consumption.

The copolymer (B) contains at least a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit, but is composed of only a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit. It may contain other monomeric units.
However, the content of the butylene unit of the copolymer (B) is preferably 0 mol%. For example, as the hydrogenated styrene-butadiene-styrene copolymer elastomer used in JP2012-246366, a hydrogenated styrene-ethylene-butylene-styrene copolymer (SEBS) containing a butylene unit is used. There is. The content of the butylene unit in the copolymer (B) is preferably 0 mol%, and the copolymer (B) preferably does not contain SEBS.

(Conjugated diene unit)
The conjugated diene unit is a structural unit derived from the conjugated diene compound as a monomer.
Here, the conjugated diene compound refers to a conjugated diene compound. The conjugated diene compound preferably has 4 to 8 carbon atoms. Specific examples of such conjugated diene compounds include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like. The conjugated diene compound may be used alone or in combination of two or more.

The conjugated diene compound as the monomer of the copolymer (B) is at least one selected from the group consisting of 1,3-butadiene and isoprene from the viewpoint of improving crack resistance and fuel efficiency of the tire. It is preferably contained, more preferably composed of at least one selected from the group consisting of 1,3-butadiene and isoprene, and even more preferably composed of only 1,3-butadiene.
In other words, the conjugated diene unit in the copolymer (B) preferably contains at least one selected from the group consisting of 1,3-butadiene units and isoprene units, preferably 1,3-butadiene units and It is more preferably composed of at least one selected from the group consisting of isoprene units, and even more preferably composed of only 1,3-butadiene units.

The content of the conjugated diene unit of the copolymer (B) is preferably 16 mol% or more, more preferably 20 mol% or more, further preferably 24 mol% or more, and 55 mol% or less. It is preferably 50 mol% or less, more preferably 47 mol% or less.
When the content of the conjugated diene unit is 16 to 55 mol% of the entire copolymer (B), the crack resistance and fuel efficiency of the tire can be improved.
From the viewpoint of further improving the crack resistance and fuel efficiency of the tire, the content of the conjugated diene unit is preferably in the range of 16 to 55 mol% of the entire copolymer (B), more preferably in the range of 20 to 50 mol%. , 24 to 47 mol% is more preferable.

(Non-conjugated olefin unit)
The non-conjugated olefin unit is a structural unit derived from the non-conjugated olefin compound as a monomer.
Here, the non-conjugated olefin compound refers to an aliphatic unsaturated hydrocarbon having one or more carbon-carbon double bonds. The non-conjugated olefin compound preferably has 2 to 10 carbon atoms. Specific examples of such non-conjugated olefin compounds include α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene, vinyl pivalate and 1-phenylthioethane. , N-Vinylpyrrolidone and other heteroatomic substituted alkene compounds and the like. The non-conjugated olefin compound may be one kind alone or a combination of two or more kinds.

The non-conjugated olefin compound as the monomer of the copolymer (B) is preferably an acyclic non-conjugated olefin compound from the viewpoint of improving crack resistance and fuel efficiency of the tire, and is also acyclic. The non-conjugated olefin compound of is more preferably an α-olefin, further preferably an α-olefin containing ethylene, and particularly preferably composed of ethylene alone.
In other words, the non-conjugated olefin unit in the copolymer (B) is preferably an acyclic non-conjugated olefin unit, and the acyclic non-conjugated olefin unit is an α-olefin unit. More preferably, it is more preferably an α-olefin unit containing an ethylene unit, and particularly preferably it is composed of only an ethylene unit.

The content of the non-conjugated olefin unit of the copolymer (B) is preferably 40 mol% or more, more preferably 42 mol% or more, further preferably 45 mol% or more, and 80 mol. % Or less, more preferably 75 mol% or less, and even more preferably 70 mol% or less.
When the content of the non-conjugated olefin unit is 40 to 80 mol% of the total amount of the copolymer (B), the crack resistance and fuel efficiency of the tire can be improved.
From the viewpoint of further improving the crack resistance and fuel efficiency of the tire, the content of the non-conjugated olefin unit is preferably in the range of 40 to 80 mol% of the entire copolymer (B), more preferably in the range of 42 to 75 mol%. It is preferable, and the range of 45 to 70 mol% is more preferable.

(Aromatic vinyl unit)
The aromatic vinyl unit is a structural unit derived from an aromatic vinyl compound as a monomer.
Since the copolymer (B) contains an aromatic vinyl unit, excessive crystallization derived from a non-conjugated olefin unit is suppressed, and while improving the rigidity of the vulcanized rubber, the elasticity is not easily impaired and high crack resistance is achieved. You can get sex.
Here, the aromatic vinyl compound refers to an aromatic compound substituted with at least a vinyl group, and is not included in the conjugated diene compound. The aromatic vinyl compound preferably has 8 to 10 carbon atoms. Examples of such aromatic vinyl compounds include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene and the like. .. The aromatic vinyl compound may be used alone or in combination of two or more.

The aromatic vinyl compound as the monomer of the copolymer (B) preferably contains styrene, and more preferably only styrene, from the viewpoint of improving the crack resistance and fuel efficiency of the tire. In other words, the aromatic vinyl unit in the copolymer (B) preferably contains a styrene unit, and more preferably consists of only a styrene unit.
The aromatic ring in the aromatic vinyl unit is not included in the main chain of the copolymer (B) unless it is bonded to an adjacent unit.

The content of the aromatic vinyl unit of the copolymer (B) is preferably 1 mol% or more, more preferably 1.5 mol% or more, and preferably 15 mol% or less, and 10 mol. More preferably, it is less than%. When the content of the aromatic vinyl unit is 1 to 15 mol% of the total amount of the copolymer (B), the crack resistance and fuel efficiency of the tire can be improved.
From the viewpoint of further improving the crack resistance and fuel efficiency of the tire, the content of the aromatic vinyl unit is preferably in the range of 1 to 15 mol% of the entire copolymer (B), and is in the range of 1.5 to 10 mol%. Is more preferable, and a range of 2 to 8 mol% is further preferable.

The number of types of monomers of the copolymer (B) is particularly limited as long as the copolymer (B) contains a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit. There is no.
The content of other structural units other than the conjugated diene unit, the non-conjugated olefin unit, and the aromatic vinyl unit is 30 mol% or less of the total copolymer (B) from the viewpoint of obtaining the desired effect of the present invention. It is preferably 20 mol% or less, more preferably 10 mol% or less, and particularly preferably not contained, that is, the content is 0 mol%.

From the viewpoint of improving the crack resistance and fuel efficiency of the tire, the copolymer (B) has only one type of conjugated diene compound, only one type of non-conjugated olefin compound, and one type of aromatic vinyl compound as monomers. It is preferable that the polymer is polymerized by using at least.
In other words, the copolymer (B) may be a copolymer (B) containing only one type of conjugated diene unit, only one type of non-conjugated olefin unit, and only one type of aromatic vinyl unit. More preferably, it is a ternary copolymer consisting of only one conjugated diene unit, only one non-conjugated olefin unit, and only one aromatic vinyl unit, 1,3-butadiene unit, ethylene unit, And a ternary copolymer composed of only styrene units is more preferable. Here, "only one type of conjugated diene unit" includes conjugated diene units having different binding modes.

The copolymer (B) has a conjugated diene unit content of 16 to 55 mol% and a non-conjugated olefin unit content of 40 to 80 mol% from the viewpoint of improving crack resistance and fuel efficiency of the tire. Moreover, the content of the aromatic vinyl unit is preferably 1 to 15 mol%.

The polystyrene-equivalent weight average molecular weight (Mw) of the copolymer (B) is preferably 250,000 to 650,000, more preferably 350,000 to 600,000, and 370,000 to 550. It is more preferably 000. When the Mw of the copolymer (B) is 250,000 or more, the crack resistance and fuel efficiency of the tire can be sufficiently ensured, and when the Mw is 650,000 or less, the rubber The workability of the composition is not easily impaired.

The copolymer (B) preferably has a polystyrene-equivalent number average molecular weight (Mn) of 90,000 to 300,000, more preferably 100,000 to 250,000, and 120,000 to 220. It is more preferably 000. When the Mn of the copolymer (B) is 90,000 or more, the crack resistance and fuel efficiency of the tire can be sufficiently ensured, and when the Mn is 10,000,000 or less. , The workability of the rubber composition is not impaired.

The copolymer (B) preferably has a molecular weight distribution [Mw / Mn (weight average molecular weight / number average molecular weight)] of 1.70 to 4.00, and more preferably 1.80 to 3.70. It is preferably 1.90 to 3.50, and more preferably 1.90 to 3.50. When the molecular weight distribution of the copolymer (B) is 4.00 or less, sufficient homogeneity can be brought about in the physical properties of the copolymer (B).

The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the copolymer (B) are determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The copolymer (B) preferably has an endothermic peak energy of 10 to 150 J / g, more preferably 30 to 120 J / g, as measured by a differential scanning calorimetry (DSC) at 0 to 120 ° C. When the endothermic peak energy of the copolymer (B) is 10 J / g or more, the crystallinity of the copolymer (B) becomes high, and the crack resistance of the tire can be further improved. Further, when the endothermic peak energy of the copolymer (B) is 150 J / g or less, the workability of the rubber composition is improved.
The endothermic peak energy of the copolymer (B) is raised from −150 ° C. to 150 ° C. using a differential scanning calorimeter according to JIS K 7121-1987, for example, at a heating rate of 10 ° C./min. And measure it.

The copolymer (B) preferably has a melting point of 30 to 100 ° C., more preferably 35 to 95 ° C., and further preferably 40 to 90 ° C., as measured by a differential scanning calorimeter (DSC). preferable. When the melting point of the copolymer (B) is 30 ° C. or higher, the crystallinity of the copolymer (B) becomes high, and the crack resistance of the tire can be further improved. Further, when the melting point of the copolymer (B) is 100 ° C. or lower, the workability of the rubber composition is improved.
The melting point of the copolymer (B) may be measured using a differential scanning calorimeter according to JIS K 7121-1987.

The copolymer (B) preferably has a glass transition temperature (Tg) of 0 ° C. or lower, more preferably −100 to −10 ° C., as measured by a differential scanning calorimeter (DSC). When the glass transition temperature of the copolymer (B) is 0 ° C. or lower, the crack resistance and fuel efficiency of the tire can be further improved.
The glass transition temperature of the copolymer (B) may be measured using a differential scanning calorimeter according to JIS K 7121-1987.

The copolymer (B) preferably has a crystallinity of 0.5 to 50%, more preferably 3 to 45%, and even more preferably 5 to 45%. When the crystallinity of the copolymer (B) is 0.5% or more, the crystallinity of the copolymer (B) due to the non-conjugated olefin unit is sufficiently ensured, and the crack resistance and low crack resistance of the tire are low. Fuel efficiency can be further improved. Further, when the crystallinity of the copolymer (B) is 50% or less, the workability and extrusion processability at the time of kneading the rubber composition are improved.
The crystallinity of the copolymer (B) is determined by measuring the crystal melting energy of polyethylene, which is a 100% crystalline component, and the melting peak energy of the copolymer (B), and the energy ratio between polyethylene and the copolymer (B). From this, the crystallinity may be calculated. In addition, the melting peak energy can be measured with a differential scanning calorimeter.

It is preferable that the main chain of the copolymer (B) has only an acyclic structure. As a result, the crack resistance and fuel efficiency of the tire can be further improved.
In addition, NMR is used as a main measuring means for confirming whether or not the main chain of the copolymer (B) has a cyclic structure. Specifically, when a peak derived from the cyclic structure existing in the main chain (for example, a peak appearing at 10 to 24 ppm for a three-membered ring to a five-membered ring) is not observed, the main of the copolymer (B) is The chain indicates that it consists only of an acyclic structure.
In the present invention, the main chain of the polymer means a linear molecular chain in which all other molecular chains (long molecular chain, short molecular chain, or both) are connected like a pendant ["". See Section 1.34 of Glossary of Basic Terms in Polymer Science IUPAC Recommendations 1996, Pure Appl. Chem., 68, 2287-2311 (1996)]
The non-cyclic structure means a linear structure or a branched structure.

The copolymer (B) can be produced through a polymerization step using a conjugated diene compound, a non-conjugated olefin compound, and an aromatic vinyl compound as monomers, and if necessary, a coupling step, a washing step, and the like. And other steps may be performed.
Here, in the production of the copolymer (B), in the presence of a polymerization catalyst, only the non-conjugated olefin compound and the aromatic vinyl compound may be added without adding the conjugated diene compound, and these may be first polymerized. preferable. In particular, when the catalyst composition described below is used, the conjugated diene compound is more reactive than the non-conjugated olefin compound and the aromatic vinyl compound. Therefore, the non-conjugated olefin compound and the aromatic compound are present in the presence of the conjugated diene compound. It is difficult to polymerize either one or both of the group vinyl compounds. Further, it is also liable to be difficult due to the characteristics of the catalyst to first polymerize the conjugated diene compound and then additionally polymerize the non-conjugated olefin compound and the aromatic vinyl compound.

As the polymerization method, any method such as a solution polymerization method, a suspension polymerization method, a liquid phase massive polymerization method, an emulsion polymerization method, a gas phase polymerization method, and a solid phase polymerization method can be used. When a solvent is used in the polymerization reaction, the solvent may be any solvent that is inactive in the polymerization reaction, and examples thereof include toluene, cyclohexane, and normal hexane.

The polymerization step may be carried out in one step or in multiple steps of two or more steps.
The one-step polymerization step is all kinds of monomers to be polymerized, namely conjugated diene compounds, non-conjugated olefin compounds, aromatic vinyl compounds, and other monomers, preferably conjugated diene compounds, non-conjugated. This is a step of simultaneously reacting an olefin compound and an aromatic vinyl compound to polymerize them.
In the multi-step polymerization step, a part or all of one or two kinds of monomers are first reacted to form a polymer (first polymerization step), and then added in the first polymerization step. This is a step of polymerizing by performing one or more steps (second polymerization step to final polymerization step) of adding and polymerizing a type of monomer that has not been polymerized, the remainder of the monomer added in the first polymerization step, and the like. .. In particular, in the production of the copolymer (B), it is preferable to carry out the polymerization step in multiple stages.

In the polymerization step, the polymerization reaction is preferably carried out in an atmosphere of an inert gas, preferably nitrogen gas or argon gas. The polymerization temperature of the polymerization reaction is not particularly limited, but is preferably in the range of -100 ° C to 200 ° C, and may be about room temperature. The pressure of the polymerization reaction is preferably in the range of 0.1 to 10.0 MPa in order to sufficiently incorporate the conjugated diene compound into the polymerization reaction system.
The reaction time of the polymerization reaction is also not particularly limited, and is preferably in the range of 1 second to 10 days, but can be appropriately selected depending on conditions such as the type of polymerization catalyst and the polymerization temperature.
Further, in the polymerization step of the conjugated diene compound, the polymerization may be stopped by using a polymerization terminator such as methanol, ethanol or isopropanol.

The polymerization step is preferably carried out in multiple steps. More preferably, the first step of mixing the first monomer raw material containing at least an aromatic vinyl compound with the polymerization catalyst to obtain a polymerization mixture, and the conjugated diene compound, the non-conjugated olefin compound and the polymerization mixture with respect to the polymerization mixture. It is preferable to carry out the second step of introducing the second monomer raw material containing at least one selected from the group consisting of aromatic vinyl compounds. Further, it is more preferable that the first monomer raw material does not contain the conjugated diene compound and the second monomer raw material contains the conjugated diene compound.

The first monomer raw material used in the first step may contain a non-conjugated olefin compound together with the aromatic vinyl compound. In addition, the first monomer raw material may contain the entire amount of the aromatic vinyl compound used, or may contain only a part of the aromatic vinyl compound. Further, the non-conjugated olefin compound is contained in at least one of the first monomer raw material and the second monomer raw material.

The first step is preferably carried out in the reactor under the atmosphere of an inert gas, preferably nitrogen gas or argon gas. The temperature (reaction temperature) in the first step is not particularly limited, but is preferably in the range of -100 ° C to 200 ° C, and may be about room temperature. The pressure in the first step is not particularly limited, but is preferably in the range of 0.1 to 10.0 MPa in order to sufficiently incorporate the aromatic vinyl compound into the polymerization reaction system. The time (reaction time) spent in the first step can be appropriately selected depending on the conditions such as the type of polymerization catalyst and the reaction temperature. For example, when the reaction temperature is 25 to 80 ° C., it is 5 minutes. The range of ~ 500 minutes is preferable.

In the first step, as the polymerization method for obtaining the polymerization mixture, any method such as a solution polymerization method, a suspension polymerization method, a liquid phase massive polymerization method, an emulsion polymerization method, a gas phase polymerization method, and a solid phase polymerization method can be used. Can be used. When a solvent is used in the polymerization reaction, the solvent may be any solvent that is inert in the polymerization reaction, and examples thereof include toluene, cyclohexanone, and normal hexane.

The second monomer raw material used in the second step is only a conjugated diene compound, a conjugated diene compound and a non-conjugated olefin compound, a conjugated diene compound and an aromatic vinyl compound, or a conjugated diene compound and a non-conjugated olefin compound. And aromatic vinyl compounds are preferred.
When the second monomer raw material contains at least one selected from the group consisting of a non-conjugated olefin compound and an aromatic vinyl compound in addition to the conjugated diene compound, these monomer raw materials are used as a solvent or the like in advance. It may be introduced into the polymerization mixture after being mixed with, or each monomer raw material may be introduced from a single state. Further, each monomer raw material may be added at the same time or sequentially.
In the second step, the method of introducing the second monomer raw material into the polymerization mixture is not particularly limited, but the flow rate of each monomer raw material is controlled and continuously added to the polymerization mixture. It is preferable to do (so-called monomering). Here, when a monomer raw material that is a gas under the conditions of the polymerization reaction system (for example, ethylene as a non-conjugated olefin compound under the conditions of room temperature and normal pressure) is used, the polymerization reaction system is carried out at a predetermined pressure. Can be introduced in.

The second step is preferably carried out in the reactor under the atmosphere of an inert gas, preferably nitrogen gas or argon gas. The temperature (reaction temperature) in the second step is not particularly limited, but is preferably in the range of -100 ° C to 200 ° C, and may be about room temperature. When the reaction temperature is raised, the selectivity of cis-1,4 bond in the conjugated diene unit may decrease. The pressure in the second step is not particularly limited, but is preferably in the range of 0.1 to 10.0 MPa in order to sufficiently incorporate a monomer such as a conjugated diene compound into the polymerization reaction system. The time (reaction time) spent in the second step can be appropriately selected depending on the conditions such as the type of polymerization catalyst and the reaction temperature, but is preferably in the range of 0.1 hour to 10 days, for example.
Further, in the second step, the polymerization reaction may be stopped by using a polymerization terminator such as methanol, ethanol or isopropanol.

Here, in the polymerization step of the above-mentioned conjugated diene compound, non-conjugated olefin compound, and aromatic vinyl compound, various monomers are used as catalyst components in the presence of one or more of the following components (A) to (F). It is preferable to include a step of polymerizing. In the polymerization step, it is preferable to use one or more of the following components (A) to (F), but it is possible to combine two or more of the following components (A) to (F) and use them as a catalyst composition. More preferred.
(A) Component: Rare earth element compound or reaction product of the rare earth element compound and Lewis base (B) Component: Organic metal compound (C) Component: Aluminoxane (D) Component: Ionic compound (E) Component: Halogen compound ( F) Ingredients: substituted or unsubstituted cyclopentadiene (compound having a cyclopentadienyl group), substituted or unsubstituted indene (compound having an indenyl group), and substituted or unsubstituted fluorene (compound having a fluorenyl group). ), The cyclopentadiene skeleton-containing compound (A) to (F) can be used in the polymerization step by referring to, for example, International Publication No. 2018/092733.

The coupling step is a step of performing a reaction (coupling reaction) for modifying at least a part (for example, a terminal) of the polymer chain of the copolymer (B) obtained in the polymerization step.
In the coupling step, it is preferable to carry out the coupling reaction when the polymerization reaction reaches 100%.
The coupling agent used in the coupling reaction is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a tin-containing compound such as bis (-1-octadecyl maleate) dioctyltin (IV); 4 , 4'-Isocyanate compounds such as diphenylmethane diisocyanate; alkoxysilane compounds such as glycidylpropyltrimethoxysilane, and the like. These may be used alone or in combination of two or more.
Among these, bis (-1-octadecyl maleate) dioctyltin (IV) is preferable in terms of reaction efficiency and low gel formation.
By carrying out the coupling reaction, the number average molecular weight (Mn) of the copolymer (B) can be increased.

The washing step is a step of washing the copolymer (B) obtained in the polymerization step.
The medium used for cleaning is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include methanol, ethanol and isopropanol. When a catalyst derived from sulfuric acid is used as the polymerization catalyst. Can be used by adding an acid (for example, hydrochloric acid, sulfuric acid, nitric acid, etc.) to these solvents. The amount of acid to be added is preferably 15 mol% or less with respect to the solvent. When the addition amount is 15 mol% or less, the acid is less likely to remain in the copolymer (B) and is less likely to adversely affect the reaction during kneading and vulcanization of the rubber composition.
By this washing step, the amount of catalyst residue in the copolymer (B) can be suitably reduced.

Further, the content of the copolymer (B) in the rubber composition is preferably more than 10% by mass, more preferably 15% by mass or more from the viewpoint of crack resistance and fuel efficiency of the tire. , More preferably in excess of 20% by mass. Further, from the viewpoint of the balance between crack resistance, weather resistance and fuel efficiency of the vulcanized rubber, the content of the copolymer (B) in the rubber component is 72% by mass or less, and 70% by mass or less. It is preferably 65% by mass or less, and more preferably 65% by mass or less.

[Anti-aging agent]
The rubber composition generally contains an anti-aging agent in order to improve weather resistance, but the rubber composition of the present invention preferably contains an anti-aging agent in an amount of less than 1% by mass.
Since the tire obtained from the rubber composition of the present invention has excellent weather resistance, it is possible to reduce the amount of anti-aging agent in the rubber composition. As a result, discoloration of the tire due to exudation of the antiaging agent is prevented, and the discoloration resistance is excellent. Specifically, the content of the anti-aging agent in the rubber composition can be less than 1% by mass. The lower limit of the content of the antiaging agent in the rubber composition is not particularly limited, but may be 0% by mass or may exceed 0% by mass.
Examples of the antiaging agent include amine-ketone compounds, imidazole compounds, amine compounds, phenol compounds, sulfur compounds and phosphorus compounds.

(Rubber component)
Examples of the rubber component other than the copolymer (A) and the copolymer (B) of the present invention include diene-based rubber.
Examples of the diene rubber include natural rubber (NR) and synthetic diene rubber.
Specific examples of the synthetic diene rubber include polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), chloroprene rubber (CR), butyl halide rubber, and acryloni little-butadiene. Examples include rubber (NBR).
As the diene rubber, one type may be used alone, or two or more types may be used. Further, the diene rubber may be modified.
The rubber component may include non-diene rubber.
From the viewpoint of maintaining a balance between crack resistance, weather resistance, and fuel efficiency of the vulcanized rubber, the rubber component is preferably composed of the copolymer (A) and the copolymer (B).

(filler)
The rubber composition of the present invention preferably contains carbon black as a filler.
When the rubber composition contains carbon black, the mechanical strength of the vulcanized rubber can be improved, and the crack resistance can be improved.
The filler may further contain an inorganic filler such as silica.

[Carbon black]
The type of carbon black is not particularly limited, and examples thereof include GPF, FEF, HAF, ISAF, and SAF, and HAF, ISAF, and SAF are preferable.
The content of carbon black in the rubber composition is preferably 20 to 80 parts by mass and 30 to 70 parts by mass with respect to 100 parts by mass of the rubber component from the viewpoint of improving the crack resistance of the vulcanized rubber. It is more preferably 40 to 60 parts by mass.

[Inorganic filler]
Examples of the inorganic filler include metal oxides such as silica, alumina, and titania, and silica is particularly preferable.
The type of silica is not particularly limited, and examples thereof include wet silica (hydrous silicic acid), dry silica (silicic anhydride), and colloidal silica.
When the rubber composition of the present invention contains silica, a silane coupling agent may be further used in the rubber composition in order to improve the dispersibility of silica.

(Various ingredients)
In addition to the rubber components and fillers described above, the rubber composition of the present invention contains, for example, stearic acid, zinc oxide, a vulcanization accelerator, and a vulcanization package containing sulfur; a softener; a resin and the like, which are commonly used in the rubber industry. Various components used can be appropriately selected and blended within a range that does not impair the object of the present invention. Commercially available products can be preferably used as these various components.
Further, the rubber composition is mixed with various components, kneaded using a closed kneading device such as a Banbury mixer, an internal mixer, an intensive mixer, a non-sealed kneading device such as a roll, and then heated. It can be prepared by putting, extruding or the like.
As each component to be blended in the production of the rubber composition, it is preferable to blend the amount indicated as the content of each component in the rubber composition as the blending amount.
The kneading of each component may be carried out in one step, or may be divided into two or more steps.

[Vulcanizing agent]
The vulcanizing agent is not particularly limited, and sulfur is usually used, and examples thereof include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur.
In the rubber composition of the present invention, the content of the vulcanizing agent is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component. When this content is 0.1 part by mass or more, vulcanization can be sufficiently proceeded, and when it is 10 parts by mass or less, the aging resistance of the vulcanized rubber can be suppressed. The content of the vulcanizing agent in the rubber composition is more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the rubber component.

[Vulcanization accelerator]
The rubber composition of the present invention may contain a vulcanization accelerator in order to promote vulcanization of the rubber component.
Examples of the vulcanization accelerator include vulcanization accelerators such as guadinin-based, sulfenamide-based, thiuram-based, thiazole-based, aldehyde amine-based, and thiocarbamate-based.
The content of the vulcanization accelerator in the rubber composition of the present invention is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component from the viewpoint of durability of the tire and the rubber crawler, and is 0. .5 to 5 parts by mass is more preferable.

[Softener]
The rubber composition of the present invention may contain a softening agent.
When the rubber composition contains a softening agent, the processability of the rubber composition is improved and the vulcanized rubber is provided with flexibility.
Softeners include petroleum-based softeners such as process oils, lubricating oils, naphthenic oils, paraffins, liquid paraffins, petroleum asphalt, and vaseline, fatty oil-based softeners such as castor oil, flaxseed oil, rapeseed oil, and palm oil, and honey. Examples thereof include waxes such as wax, carnauba wax, and lanolin. These softeners may be used alone or in combination of two or more.
The content of the softening agent in the rubber composition is preferably 0 to 30 parts by mass, and more preferably 0 to 20 parts by mass with respect to 100 parts by mass of the rubber component.

<Tire>
The tire of the present invention is made by using the rubber composition of the present invention.
Therefore, the tire of the present invention has an excellent balance of crack resistance, weather resistance, and fuel efficiency. From this point of view, the tire of the present invention is preferably a tire using the rubber composition of the present invention for treads, sidewalls, shoulders and the like.
Tire treads, sidewalls, shoulders and the like can be manufactured by molding the rubber composition of the present invention and then vulcanizing it. The tire tread is particularly preferably used as a tread ground contact portion (also referred to as a tread portion).
Further, the rubber composition of the present invention is used for a tread, a sidewall, a shoulder, etc., and a tire is manufactured by a usual tire manufacturing method. That is, the rubber composition of the present invention containing various components as described above is processed into treads, sidewalls, shoulders, etc. at the stage of unvulcanization, and is pasted and molded on a tire molding machine by a usual method. Raw tires are molded. The raw tire is heated and pressurized in a vulcanizer to obtain a tire.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for the purpose of exemplifying the present invention and do not limit the present invention in any way.

<Preparation of rubber composition and production of vulcanized rubber>
A rubber composition was prepared according to the formulation shown in Table 2 and heated at 160 ° C. for 20 minutes to obtain a vulcanized rubber.
The details of the components in Table 2 are as follows.
Copolymer (A): Ethylene-propylene-diene rubber, manufactured by JSR Corporation, trade name "EP35", diene content 8 mol%
Copolymer (B1): Copolymer (B) produced by the following production method
Copolymer (B2): Copolymer (B) produced by the following production method
Copolymer (C): Ethylene-butadiene copolymer (EBR) produced by the following production method.
Carbon Black: ISAF Grade Carbon Black Process Oil: Made by Idemitsu Kosan Co., Ltd., Product Name "Diana Process Oil PS-90"
The vulcanization package contains stearic acid, zinc oxide, vulcanization accelerator and sulfur.

[Production of copolymers (B1) and (B2)]
1. 1. Method for Synthesizing Copolymer (B1) 91 g of styrene and 379 g of toluene were added to a sufficiently dried 2000 mL pressure resistant stainless steel reactor.
In a glove box under a nitrogen atmosphere, in a glass container, 0.1 mmol of mono (bis (1,3-tert-butyldimethylsilyl) indenyl) bis (bis (dimethylsilyl) amide) gadolinium complex 1,3- [ (T-Bu) Me ₂ Si] ₂ C ₉ H ₅ Gd [N (SiHMe ₂ ) ₂ ], 0.1 mmol dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] And 1.3 mmol of triisobutylaluminum were charged, and 63 mL of toluene was added to prepare a catalytic solution. The catalyst solution was added to the pressure resistant stainless steel reactor and heated to 60 ° C.

Next, ethylene was charged into the pressure-resistant stainless steel reactor at a pressure of 1 to 1.5 MPa, and copolymerization was carried out at 75 ° C. for a total of 4 hours. Continuously 1.1 to 1.2 mL / min. At the same rate, 280 g of toluene solution containing 70 g of 1,3-butadiene was added.
Then, 1 mL of an isopropanol solution containing 5% by mass of 2,2'-methylene-bis (4-ethyl-6-t-butylphenol) (NS-5) was added to the pressure-resistant stainless steel reactor to terminate the reaction.
Then, the copolymer was separated using a large amount of methanol and vacuum dried at 50 ° C. to obtain a copolymer (B1).

2. Method for Synthesizing Copolymer (B2) 30 g of styrene and 368 g of toluene were added to a sufficiently dried 2000 mL pressure resistant stainless steel reactor.
In a glove box under a nitrogen atmosphere, 0.0375 mmol of mono (bis (1,3-tert-butyldimethylsilyl) indenyl) bis (bis (dimethylsilyl) amide) gadolinium complex 1,3-[ (T-Bu) Me ₂ Si] ₂ C ₉ H ₅ Gd [N (SiHMe ₂ ) ₂ ], 0.0375 mmol of dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] And 1.2 mmol of triisobutylaluminum were charged, and 10 mL of toluene was added to prepare a catalytic solution. The catalyst solution was added to the pressure resistant stainless steel reactor and heated to 60 ° C.

Next, ethylene was charged into the pressure-resistant stainless steel reactor at a pressure of 1.0 MPa, and copolymerization was carried out at 75 ° C. for a total of 4 hours. Continuously 1.5-1.6 mL / min. At the same rate, 357 g of toluene solution containing 90 g of 1,3-butadiene was added.
Then, 1 mL of an isopropanol solution containing 5% by mass of 2,2'-methylene-bis (4-ethyl-6-t-butylphenol) (NS-5) was added to the pressure-resistant stainless steel reactor to terminate the reaction.
Then, the copolymer was separated using a large amount of methanol and vacuum dried at 50 ° C. to obtain a copolymer (B2).

The obtained copolymer (B1) and copolymer (B2) had the physical characteristics shown in Table 1.

^{Since no peak was observed at 10 to 24 ppm in the 13} C-NMR spectrum chart of the copolymer (B1) and the copolymer (B2), it was confirmed that the main chain consisted only of an acyclic structure.

[Production of copolymer (C)]
After adding 2,000 g of a toluene solution containing 120 g (2.22 mol) of 1,3-butadiene to a sufficiently dried 4 L stainless steel reactor, ethylene was introduced at 1.72 MPa. On the other hand, in a glove box under a nitrogen atmosphere, into a glass container, bis 28.5Myumol (2-phenyl indenyl) gadolinium bis (dimethylsilyl _{amide) [(2-PhC 9 H} 6) 2 GdN (SiHMe 2) ₂ ], 28.5 μmol of dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ], and 2.00 mmol of diisobutylaluminum hydride were charged and dissolved in 40 ml of toluene to provide a catalytic solution. And said. Then, the catalyst solution was taken out from the glove box, an amount of 25.0 μmol in terms of gadolinium was added to the monomer solution, and polymerization was carried out at 50 ° C. for 90 minutes. After the polymerization, 5 ml of an isopropanol solution containing 5% by mass of 2,2'methylene-bis (4-ethyl-6-t-butylphenol) (NS-5) was added to terminate the reaction, and a larger amount of methanol was added to the copolymer. The coalescence was separated and vacuum dried at 70 ° C. to obtain an ethylene-butadiene copolymer (EBR) (copolymer (C)).
The obtained copolymer (C) had a yield of 98 g, a diene content of 91 mol%, an ethylene content of 9 mol%, a weight average molecular weight Mw of 358,000, and a molecular weight distribution Mw / Mn of 2.5. ..

The physical properties of the copolymer (B1), the copolymer (B2) and the copolymer (C) were measured by the following methods.

[Method for measuring physical properties of copolymer]
(1) Number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn)
Gel permeation chromatography [GPC: HLC-8121 GPC / HT manufactured by Toso Co., Ltd., column: GMH _HR- H (S) HT x 2, manufactured by Toso Co., Ltd., detector: differential refractometer (RI)] to obtain monodisperse polystyrene. As a reference, the polystyrene-equivalent number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the copolymer were determined. The measurement temperature is 40 ° C.

(2) Content of ethylene unit, butadiene unit, styrene unit The content (mol%) of ethylene unit, butadiene unit, and styrene unit in the copolymer is determined by ¹ H-NMR spectrum (100 ° C, d-tetrachloroethane standard). : 6 ppm) was calculated from the integration ratio of each peak.

(3) Confirmation of main chain structure ¹³ C-NMR spectrum was measured for the synthesized copolymer.

<Evaluation>
1. 1. Low fuel consumption For each of the vulcanized rubbers of Examples 1 to 4 and Comparative Examples 1 to 5, using the trade name "ARES-G2" manufactured by TA Instruments, the frequency is 15 Hz, the shear strain is 10%, and the temperature is 50. A viscoelasticity test was performed under the condition of ° C. The reciprocal of the loss tangent tan δ obtained from the viscoelasticity test was calculated, and the reciprocal of the loss tangent tan δ of Comparative Example 1 was set to 100. The reciprocal was indexed to obtain the fuel efficiency index.
The higher the fuel efficiency index, the better the fuel efficiency of the tire obtained from the vulcanized rubber. The fuel efficiency index is 80 or more, preferably 85 or more, and more preferably 90 or more.

2. Crack resistance Each vulcanized rubber of Examples 1 to 4 and Comparative Examples 1 to 5 was cut into a JIS No. 3 test piece, a 0.5 mm crack was formed in the center of the test piece, and 40% at 40 ° C. A repeated tensile fatigue test was conducted in which repeated fatigue was applied with a constant strain of 60% and 80%. In this repeated tensile fatigue test, an ^{approximate straight line consisting of the tear energy (J / m 2} ) when each strain is applied and the number of fractures is created, and the common logarithmic value of ^{the tear energy (J / m 2) is 3.75.} The hour value was standardized so that Comparative Example 1 was 100.
The higher the crack resistance index, the better the crack resistance of the tire obtained from the vulcanized rubber. The crack resistance index is 260 or more, preferably 500 or more, and more preferably 1900 or more.

3. 3. Weather resistance Each of the vulcanized rubbers of Examples 1 to 4 and Comparative Examples 1 to 5 is exposed to an atmosphere of 40 ° C., 20% dynamic strain, and an ozone concentration of 50 pphm with an ozone weather meter manufactured by Suga Test Instruments Co., Ltd. did. Forty-eight hours after the start of exposure, it was visually determined whether or not the vulcanized rubber had cracks.
If the vulcanized rubber is not cracked, it means that the tire obtained from the vulcanized rubber has excellent weather resistance.

As can be seen from Table 2, the vulcanized rubber of Comparative Example 1 in which only ethylene-propylene-diene rubber, which is the copolymer (A), was used as the rubber component was excellent in weather resistance, but not in crack resistance. Further, the vulcanized rubbers of Comparative Examples 4 and 5 containing 28% by mass or more of the copolymer (A) in the rubber component were not excellent in weather resistance.
Compared to Comparative Examples 2 and 3 having a configuration containing ethylene-propylene-diene rubber (EPDM) and ethylene-butadiene copolymer (EBR) as in Patent Document 1, the vulcanized rubbers of Examples 1 to 4 have low fuel consumption. , It is excellent in crack resistance and weather resistance, and it can be seen that the balance between crack resistance, weather resistance and fuel efficiency is improved as compared with the conventional case. Further, although the vulcanized rubbers of Examples 1 to 4 do not contain an antiaging agent, they are excellent in weather resistance as shown in Table 2.
By applying the vulcanized rubber having an improved balance of crack resistance, weather resistance, and fuel efficiency to the tire, it is possible to obtain a tire having an improved balance of crack resistance, weather resistance, and fuel efficiency. it can.

Claims (10)

Contains a non-conjugated diene compound-non-conjugated olefin copolymer (A) containing an ethylene-propylene-diene rubber and a copolymer (B) containing a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit. Contains rubber components,
A rubber composition in which the content of the non-conjugated diene compound-non-conjugated olefin copolymer (A) in the rubber component is 28% by mass or more. The rubber composition according to claim 1, wherein the content of the antiaging agent is less than 1% by mass. The copolymer (B) has a content of the conjugated diene unit of 16 to 55 mol%, a content of the non-conjugated olefin unit of 40 to 80 mol%, and a content of the aromatic vinyl unit of 1. The rubber composition according to claim 1 or 2, which is ~ 15 mol%. The rubber composition according to any one of claims 1 to 3, wherein the content of the non-conjugated diene compound-non-conjugated olefin copolymer (A) in the rubber component is less than 90% by mass. The rubber composition according to any one of claims 1 to 4, wherein the copolymer (B) has a polystyrene-equivalent weight average molecular weight of 250,000 to 650,000. The rubber composition according to any one of claims 1 to 5, wherein the copolymer (B) is a non-conjugated olefin unit in which the non-conjugated olefin unit is acyclic. The rubber composition according to claim 6, wherein the copolymer (B) is composed of only ethylene units as the acyclic non-conjugated olefin unit. The rubber composition according to any one of claims 1 to 7, wherein the copolymer (B) contains a styrene unit in the aromatic vinyl unit. The rubber composition according to any one of claims 1 to 8, wherein the copolymer (B) contains at least one of the conjugated diene units selected from the group consisting of 1,3-butadiene units and isoprene units. Stuff. A tire using the rubber composition according to any one of claims 1 to 9.