JP2014043515A - Modified conjugated diene-based polymer composition, and tire employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modified conjugated diene-based polymer composition, a vehicle tire or the like for example, made by molding the modified conjugated diene-based polymer composition exhibiting a good low rolling-resistance and an excellent wear resistance, tensile strength and tear strength.SOLUTION: A modified conjugated diene-based polymer composition according to the present invention comprises: 100 pts.mass of a rubber constituent (A) comprising 10 to 90 wt.% of a modified conjugated diene-based polymer (a) which is obtained by reacting a conjugated diene-based polymer having a polymerization-active terminal, the conjugated diene-based polymer being obtained by polymerizing a conjugated diene compound or co-polymerizing a conjugated diene compound and an aromatic vinyl compound using polyfunctional anionic initiator, with a modifier having a functional group reactive with the polymerization-active terminal of the conjugated diene-based polymer, and 10 to 90 wt.% of a rubbery polymer (b) other than the modified conjugated diene polymer (a); and 1 to 40 mass% of carbon nanofibers (B) having an average diameter of 0.5 to 500 nm.

Description

  The present invention relates to a modified conjugated diene polymer composition and a tire using the same.

  In recent years, environmental considerations such as the suppression of carbon dioxide emissions have become social demands. Specifically, demands for reducing fuel consumption for automobiles are increasing. Under such circumstances, development of materials having low rolling resistance has been demanded as automobile tires. Similarly, a sidewall portion in an automobile tire is required to have low rolling resistance, while development of a material having wear resistance and durability, for example, high tear strength and high tensile strength is required.

  Conventionally, fillers such as carbon black and silica have been used as reinforcing fillers for tires. In particular, when silica is used, there is an advantage that low hysteresis loss and wet skid resistance can be improved.

  As a technology to disperse fillers such as carbon black and silica in rubber (conjugated diene polymer), functional groups having affinity and reactivity with fillers have been added to the end of rubber molecules with high mobility. The technology to be introduced is used. By this technology, attempts have been made to reduce the hysteresis loss by improving the dispersibility of the filler in the rubber material and further sealing the rubber molecule terminal portion with a bond with the filler (for example, Patent Documents 1 to 3). 4).

  On the other hand, diene rubber is polymerized using a polyfunctional anionic polymerization initiator and then modified with a modifier such as a glycidylamino group to increase the number of functionalized polymer ends. A technique for improving the performance of a composition composed of silica and silica, that is, silica dispersibility and reducing hysteresis loss (for example, see Patent Document 5) has been proposed.

  However, these compositions have room for improvement, for example, with respect to wear resistance and durability, which are required characteristics of sidewalls.

  Therefore, in recent years, the use of short fibers such as carbon nanofibers as a reinforcing agent for sidewall materials has been studied. For example, a rubber composition for tires in which cut fibers are improved by blending short fibers with diene-based synthetic rubber has been disclosed (see, for example, Patent Documents 6 and 7).

  In addition, natural rubber and polybutadiene (high cis polybutadiene) having a large amount of cis bonds in the conjugated diene portion are generally used as a rubber component of a rubber composition for tires because of its excellent wear resistance, fracture strength, and cold resistance. It is done.

International Publication No. 01/23467 Pamphlet Japanese Patent Application Laid-Open No. 07-233217 JP 2001-158834 A JP 2003-171418 A JP 2006-306962 A Japanese Patent Laid-Open No. 06-255321 JP 2008-156458 A

  However, in conventional rubber blended rubber compositions such as carbon nanotubes and carbon nanofibers, and natural rubber or high cis polybutadiene blended rubber compositions, low rolling resistance is not sufficient.

  The object of the present invention is, for example, a modified conjugated diene polymer composition having good low rolling resistance, excellent wear resistance, tensile strength and tear strength when molded into a sidewall of a vehicle tire or the like. Is to provide things.

  As a result of intensive studies to solve the above problems, the present inventors obtained a conjugated diene polymer by polymerization using a polyfunctional anionic polymerization initiator, and polymerized active terminals of the conjugated diene polymer. A modified conjugated diene polymer obtained by modifying a compound with a specific functional group is blended with other rubber components such as natural rubber or high cis polybutadiene, and a specific amount of specific carbon nanofibers is added. In some cases, the modification effect improves the interaction with carbon nanofibers, and natural rubber and high cis polybutadiene blends provide excellent tear strength, tensile strength, and wear resistance while maintaining sufficient low rolling resistance. The present inventors have found that a modified conjugated diene polymer composition can be obtained and have completed the present invention.

  That is, the present invention is as follows.

[1]
(A) A conjugated diene polymer having a polymerization initiation end obtained by polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anionic polymerization initiator, Modified conjugated diene polymer (a) obtained by reacting a modifier having a functional group capable of reacting at the polymerization active terminal of the conjugated diene polymer: 10 to 90% by mass, and modified conjugated diene polymer (a) 100 parts by mass of a rubber component containing 10 to 90% by mass of a rubbery polymer (b) other than
(B) Carbon nanofibers having an average diameter of 0.5 to 500 nm: 1 to 40 parts by mass,
A modified conjugated diene polymer composition comprising:

[2]
The modified conjugated diene according to [1], comprising 0.5 to 200 parts by mass of at least one reinforcing filler selected from the group consisting of a silica-based inorganic filler, a metal oxide, a metal hydroxide, and carbon black. -Based polymer composition.

[3]
The functional group capable of reacting with the polymerization active terminal of the conjugated diene polymer is selected from the group consisting of a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, an alkoxysilane group, a carboxyl group, an acid anhydride group, and an isocyanate group. The modified conjugated diene polymer composition according to [1] or [2], which is at least one kind of functional group.

[4]
[1] to [3] The modified conjugated diene polymer is a modified conjugated diene polymer in which at least one atomic group selected from the group consisting of the following formulas (1) to (16) is bonded. ] The modified | denatured conjugated diene type polymer composition in any one of.

(In the above formulas (1) to (16),
N represents a nitrogen atom, Si represents a silicon atom, O represents an oxygen atom, C represents a carbon atom, H represents a hydrogen atom,
R ¹ and R ² each independently represent a hydrogen atom or a linear or cyclic hydrocarbon group having 1 to 24 carbon atoms, and each of the hydrocarbon groups independently represents a hydroxyl group, an epoxy group, an amino group, carbon It may have at least one functional group selected from the group consisting of an imino group having a hydrocarbon group of 1 to 24, a silanol group and an alkoxysilane group of 1 to 24 carbon atoms,
R ³ each independently represents a linear or cyclic hydrocarbon group having 1 to 48 carbon atoms, and each hydrocarbon group independently represents a hydroxyl group, an epoxy group, an amino group, or a carbon atom having 1 to 24 carbon atoms. It may have at least one functional group selected from the group consisting of an imino group having a hydrogen group, a silanol group and an alkoxysilane group having 1 to 24 carbon atoms,
Each R ⁴ independently represents a hydrogen atom or a linear or cyclic hydrocarbon group having 1 to 24 carbon atoms;
n and m are each independently 1 or 2. )
[5]
The modified conjugated diene polymer composition according to any one of [1] to [4], wherein the amount of bound rubber in the modified conjugated diene polymer composition is 20% by mass or more.

[6]
The modified conjugated diene polymer composition according to any one of [1] to [5], wherein the rubber (b) component is at least one selected from the group consisting of natural rubber and high cis polybutadiene.

[7]
A tire composition comprising the modified conjugated diene polymer composition according to any one of [1] to [6].

[8]
A tire sidewall composition comprising the tire composition according to [7].

[9]
[7] A tire comprising the tire composition according to [7].

[10]
A tire sidewall comprising the tire sidewall composition according to [8].

  According to the present invention, for example, when formed into a vehicle tire or the like, the rolling resistance is small, the wear resistance is excellent, and the tensile strength and tear strength (hereinafter also referred to as “breaking strength”). Can provide a good modified conjugated diene polymer composition.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be specifically described. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist.

≪Modified conjugated diene polymer composition≫
The modified conjugated diene polymer composition of the present embodiment is obtained by polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using (A) a polyfunctional anionic polymerization initiator. Modified conjugated diene polymer (a) obtained by reacting the resulting conjugated diene polymer having a polymerization active terminal with a modifier having a functional group capable of reacting with the polymerization active terminal of the conjugated diene polymer: 100 parts by mass of a rubber component containing 10 to 90% by mass and a rubbery polymer (b) other than the modified conjugated diene polymer (a) (10) to 90% by mass; and (B) an average diameter of 0.5 to 500 nm. Carbon nanofibers: 1 to 40 parts by mass.

<(A) Rubber component>
The rubber component (A) used in the present embodiment is a specific modified conjugated diene polymer (a): 10 to 90% by mass, and a rubbery polymer (b) 10 other than the modified conjugated diene polymer (a). -90 mass% is included. In the rubber component (A) used in the present embodiment, the content of the modified conjugated diene polymer (a) is preferably 25 to 80% by mass, more preferably 30 to 70% by mass, The content of the rubber-like polymer (b) is preferably 20 to 75% by mass, and more preferably 30 to 70% by mass.

[(A) Modified conjugated diene polymer]
The modified conjugated diene polymer (a) used in the present embodiment is obtained by polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anionic polymerization initiator. It can be obtained by reacting a conjugated diene polymer having a polymerization active terminal with a modifier having a functional group capable of reacting with the polymerization active terminal of the conjugated diene polymer.

  (A) The modified conjugated diene polymer may be used alone or in combination of two or more.

[Polyfunctional anionic polymerization initiator]
First, the polyfunctional anionic polymerization initiator used for obtaining the conjugated diene polymer before modification will be described. As the polyfunctional anionic polymerization initiator, a lithiated polyvinyl aromatic compound can be used. For example, a polyfunctional anionic polymerization initiator can be prepared by reacting a polyvinyl aromatic compound and an organic lithium compound. The polyfunctional anionic polymerization initiator is preferably a polyfunctional anionic polymerization initiator prepared in a molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) in the range of 0.01 to 1.0. .

  The method for reacting the polyvinyl aromatic compound and the organolithium compound is not particularly limited. For example, the method for reacting the organolithium compound and the polyvinyl aromatic compound in a hydrocarbon solvent; the organolithium compound and the conjugated diene compound. A method of reacting a polyvinyl aromatic compound after reacting; and a method of reacting an organic lithium compound and a monovinyl aromatic compound and then reacting a polyvinyl aromatic compound; a conjugated diene compound and / or a monovinyl aromatic compound; Examples thereof include a method of reacting an organolithium compound in the presence of two or three of the polyvinyl aromatic compound. Among them, a method of reacting an organolithium compound and a polyvinyl aromatic compound in a hydrocarbon solvent; a method of reacting an organolithium compound and a conjugated diene compound and then reacting the polyvinyl aromatic compound; a conjugated diene compound and A method of reacting an organolithium compound in the presence of a polyvinyl aromatic compound is preferred.

  The polyfunctional anionic polymerization initiator prepared as described above is used for polymerization of a conjugated diene compound described later. In order to promote and stabilize the formation of the polyfunctional anionic polymerization initiator, it is preferable to add a Lewis base into the system during the preparation.

  A polyfunctional anionic polymerization initiator may be used individually by 1 type, and may be used together 2 or more types.

(Polyvinyl aromatic compound)
It does not specifically limit as a polyvinyl aromatic compound used for preparation of a polyfunctional anionic polymerization initiator, For example, o, m, and p-divinylbenzene, o, m, and p-diisopropenylbenzene, 1,2,4- Trivinylbenzene, 1,2-vinyl-3,4-dimethylbenzene, 1,3-divinylnaphthalene, 1,3,5-trivinylnaphthalene, 2,4-divinylbiphenyl, 3,5,4'-trivinyl Biphenyl, 1,2-divinyl-3,4-dimethylbenzene, 1,5,6-trivinyl-3,7-diethylnaphthalene and the like can be mentioned. These may be used alone or in combination of two or more. Among these, divinylbenzene and diisopropenylbenzene are preferable. A mixture of these o-, m- and p- isomers may also be used. For industrial use, it is economically advantageous to use a mixture of these isomers.

(Conjugated diene compounds and aromatic vinyl compounds)
For the preparation of the polyfunctional anionic polymerization initiator, a conjugated diene compound and / or a monovinyl aromatic compound can be used together with the polyvinyl aromatic compound.

  Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, 1,3-hexadiene and the like can be mentioned. Among these, 1,3-butadiene and isoprene are preferable.

  Examples of the monovinyl aromatic compound include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and the like. Among these, styrene is preferable.

  The conjugated diene compound and / or monovinyl aromatic compound has a polystyrene-equivalent weight average molecular weight of 500 to 20,000 as measured by GPC (gel permeation chromatography) using tetrahydrofuran as a mobile phase. It is preferable to add so that it may become inside, and it is still more preferable to add so that it may become 1,000-10,000.

(Organic lithium compound)
The organolithium compound used for the preparation of the polyfunctional anionic polymerization initiator is not particularly limited. For example, n-butyllithium, sec-butyllithium, tert-butyllithium, n-propyllithium, iso-propyllithium, benzyllithium Monoorganolithium compounds such as 1,4-dilithiobutane, 1,5-dilithiopentane, 1,6-dilithiohexane, 1,10-dilithiodecane, 1,1-dilithiodiphenylene, dilithiopolybutadiene, dilithiopolyisoprene 1,4-dilithiobenzene, 1,2-dilithio-1,2-diphenylethane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-trilithio Polyfunctional organolithium compounds such as -2,4,6-triethylbenzene It is. Among these, monoorganolithium compounds of n-butyllithium, sec-butyllithium, and tert-butyllithium are preferable.

(solvent)
The solvent used for the preparation of the polyfunctional anionic polymerization initiator is not particularly limited, and examples thereof include aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; benzene, Aromatic hydrocarbons such as toluene and xylene are exemplified.

(Lewis base)
In order to promote or stabilize the formation of the polyfunctional anionic polymerization initiator, it is preferable to add a Lewis base in the system. Examples of Lewis bases include tertiary monoamines, tertiary diamines, chain or cyclic ethers, and the like.

  Examples of the tertiary monoamine include trimethylamine, triethylamine, methyldiethylamine, 1,1-dimethoxytrimethylamine, 1,1-diethoxytrimethylamine, 1,1-diethoxytriethylamine, N, N-dimethylformamide diisopropyl acetal, N, N-dimethylformamide dicyclohexyl acetal etc. are mentioned.

  As the tertiary diamine, for example, N, N, N ′, N′-tetramethyldiaminomethane, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyl Propanediamine, N, N, N ′, N′-tetramethyldiaminobutane, N, N, N ′, N′-tetramethyldiaminopentane, N, N, N ′, N′-tetramethylhexanediamine, dip Examples thereof include peridinopentane and dipiperidinoethane.

  Examples of chain ethers include dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene dimethyl ether.

  Examples of the cyclic ether include tetrahydrofuran, bis (2-oxolanyl) ethane, 2,2-bis (2-oxolanyl) propane, 1,1-bis (2-oxolanyl) ethane, and 2,2-bis (2-oxolanyl). ) Butane, 2,2-bis (5-methyl-2-oxolanyl) propane, 2,2-bis (3,4,5-trimethyl-2-oxolanyl) propane and the like.

  Among the Lewis bases, trimethylamine, which is a tertiary monoamine, triethylamine, N, N, N ′, N′-tetramethylethylenediamine, which is a tertiary diamine, and tetrahydrofuran, which is a cyclic ether, are preferable.

  The amount of the polyvinyl aromatic compound used for the preparation of the polyfunctional anionic polymerization initiator is preferably in the range of 0.01 to 1.0 mol with respect to 1 mol of lithium of the organolithium compound. A range of 0.5 mol is more preferred.

  The greater the amount of polyvinyl aromatic compound used in preparing the polyfunctional anionic polymerization initiator, the greater the proportion of molecular chain terminals to which functional groups are imparted by the modification reaction described later. The affinity and reactivity with the filler are improved, and the rolling resistance performance, wear resistance and fracture characteristics of the modified conjugated diene polymer composition are improved. From such a viewpoint, the amount of the polyvinyl aromatic compound used in preparing the polyfunctional anionic polymerization initiator is preferably 0.01 mol or more, from the viewpoint of improving the workability at the time of kneading the composition. 1.0 mol or less is preferable.

  In addition, when a Lewis base is added when preparing a polyfunctional anionic polymerization initiator, it is preferably added in the range of 30 to 50,000 ppm with respect to the solvent used for the preparation of the polymerization initiator. It is more preferable to add within the range of ˜20,000 ppm. In order to fully express the effect of promoting and stabilizing the reaction, it is preferable to add a Lewis base at 30 ppm or more, to ensure the freedom of microstructure adjustment in the subsequent polymerization step and to use a solvent after polymerization. In view of recovery and separation from the polymerization solvent in the purification step, it is preferable to add the Lewis base at 50,000 ppm or less.

  Although the temperature at the time of preparing a polyfunctional initiator is not specifically limited, The range of 10 to 140 degreeC is preferable, and the range of 35 to 110 degreeC is more preferable. From the viewpoint of productivity, the temperature is preferably 10 ° C. or higher, and preferably 140 ° C. or lower in order to suppress side reactions due to high temperatures. The reaction time for preparing the polyfunctional initiator depends on the reaction temperature, but is preferably in the range of 5 minutes to 24 hours.

(Conjugated diene polymer)
The conjugated diene polymer constituting the modified conjugated diene polymer (a) will be described. The conjugated diene polymer constituting the component (a) is obtained by polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using the polyfunctional anionic polymerization initiator described above. It is.

  In the polymerization step, a polyfunctional anionic polymerization initiator may be prepared in advance in a predetermined reactor, and supplied to a reactor for polymerizing a conjugated diene compound to perform a polymerization or copolymerization reaction, A polyfunctional anionic polymerization initiator may be prepared in a reactor for performing polymerization or copolymerization described later, and a predetermined monomer may be supplied to the reactor to perform a polymerization reaction. From the viewpoint of productivity and quality stability at the time of mass production of a polymer, a polyfunctional anionic polymerization initiator is prepared in advance in a predetermined reactor, and this is used as a reactor for polymerization as required. It is preferable to carry out the polymerization of the conjugated diene compound or the copolymerization of the conjugated diene compound and the aromatic vinyl compound.

  The polymerization for obtaining the conjugated diene polymer is preferably carried out by a polymerization system such as a batch system or a continuous system in one reactor or two or more connected reactors.

  The polymerization temperature for obtaining the conjugated diene polymer is not particularly limited as long as the living anion polymerization proceeds, but is preferably 0 ° C. or higher from the viewpoint of productivity, and to the active terminal after the completion of the polymerization. It is preferable to carry out at 120 degrees C or less from a viewpoint of ensuring sufficient modification reaction amount. More preferably, it is the range of 20 to 100 degreeC, More preferably, it is the range of 30 to 90 degreeC. The polymerization temperature can be controlled by taking into consideration that the polymerization is an exothermic reaction, further adjusting the monomer and solvent feed temperatures, controlling the monomer concentration, and cooling and heating from the outside of the reactor.

(Conjugated diene compounds)
Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, 1,3-hexadiene and the like can be mentioned. Of these, 1,3-butadiene and isoprene are preferred. These may be used alone or in combination of two or more. That is, the conjugated diene polymer may be a homopolymer or a copolymer.

(Aromatic vinyl compound)
Examples of the aromatic vinyl compound include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and styrene is particularly preferable.

(Polar compound)
When producing a conjugated diene polymer, it is preferable to add the following polar compound as a vinylating agent for controlling the microstructure of the conjugated diene part and for the purpose of improving the polymerization rate.

  Examples of the polar compound include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis (2-oxolanyl) propane; Tertiary amine compounds such as methylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; alkali metal alkoxides such as potassium tert-amylate, potassium tert-butylate, sodium tert-butylate, sodium amylate Compound: Examples include phosphine compounds such as triphenylphosphine. These polar compounds may be used alone or in combination of two or more.

  The amount of the polar compound used is selected according to the purpose of the modified conjugated diene polymer composition to be obtained and the degree of effect, but is 0.005 to 1 mol of lithium in the polyfunctional anionic polymerization initiator. It is preferably 100 moles.

(Polymerization solvent)
The conjugated diene polymer is preferably polymerized in a predetermined solvent. The solvent is not particularly limited, and for example, a hydrocarbon solvent such as a saturated hydrocarbon or an aromatic hydrocarbon is used. Specifically, aliphatic hydrocarbons such as butane, pentane, hexane and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; A hydrocarbon solvent composed of a mixture thereof can be mentioned.

  It is preferable that the conjugated diene compound and the polymerization solvent described above are each used alone or a mixture thereof is treated with an organometallic compound. Thereby, the allenes and acetylenes contained in the conjugated diene compound and the polymerization solvent can be treated. As a result, a polymer having a high concentration of active terminals can be obtained, and a high modification rate can be achieved.

(Modifier)
Next, the modifying agent will be described.

  The modifier used in the present embodiment has a functional group capable of reacting with the polymerization active terminal of the conjugated diene polymer.

  The functional group capable of reacting with the polymerization active terminal of the conjugated diene polymer includes a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, and an alkoxysilane from the viewpoint of reducing rolling resistance due to interaction with carbon nanofibers. It is preferably at least one functional group selected from the group consisting of a group, a carboxyl group, an acid anhydride group and an isocyanate group.

  Specifically, as the modifier used in the present embodiment, at least one atomic group selected from the group consisting of the following formulas (1) to (16) is used as the polymerization active terminal of the conjugated diene polymer. A modifying agent to be bonded is preferable.

  That is, the modified conjugated diene polymer is a modified conjugated diene polymer in which at least one atomic group selected from the group consisting of the following formulas (1) to (16) is bonded to the polymerization active terminal. It is preferable. When such a composition containing a modified conjugated diene polymer is formed into a molded article such as a vehicle tire, the rolling resistance is small, the wear resistance is excellent, and the tensile strength and tear strength tend to be good. It is in.

(In the above formulas (1) to (16),
N represents a nitrogen atom, Si represents a silicon atom, O represents an oxygen atom, C represents a carbon atom, H represents a hydrogen atom,
R ¹ and R ² each independently represent a hydrogen atom or a linear or cyclic hydrocarbon group having 1 to 24 carbon atoms, and each of the hydrocarbon groups independently represents a hydroxyl group, an epoxy group, an amino group, carbon It may have at least one functional group selected from the group consisting of an imino group having a hydrocarbon group of 1 to 24, a silanol group and an alkoxysilane group of 1 to 24 carbon atoms,
R ³ each independently represents a linear or cyclic hydrocarbon group having 1 to 48 carbon atoms, and each hydrocarbon group independently represents a hydroxyl group, an epoxy group, an amino group, or a carbon atom having 1 to 24 carbon atoms. It may have at least one functional group selected from the group consisting of an imino group having a hydrogen group, a silanol group and an alkoxysilane group having 1 to 24 carbon atoms,
R ⁴ each independently represents a hydrogen atom or a chain or cyclic hydrocarbon group having 1 to 24 carbon atoms, and n and m are each independently 1 or 2. )
Examples of the modifier for bonding the atomic group represented by the above formulas (1) to (16) to the polymerization active terminal of the conjugated diene polymer include, for example, tetraglycidylmetaxylenediamine, tetraglycidyl-1,3- Bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyldiaminodiphenylmethane, diglycidylaniline, diglycidylorthotoluidine are mentioned.

  Also, for example, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl Tripropoxysilane, γ-glycidoxypropyl tributoxysilane, γ-glycidoxypropyltriphenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropyl Examples include ethyldiethoxysilane.

  Further, for example, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ- Glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyldiethylethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, γ-glycidoxypropyldiethylmethoxysilane, γ- Examples thereof include glycidoxypropylmethyldiisopropeneoxysilane, bis (γ-glycidoxypropyl) dimethoxysilane, and bis (γ-glycidoxypropyl) diethoxysilane.

  Still further, for example, bis (γ-glycidoxypropyl) dipropoxysilane, bis (γ-glycidoxypropyl) dibutoxysilane, bis (γ-glycidoxypropyl) diphenoxysilane, bis (γ-glycid Xypropyl) methylmethoxysilane, bis (γ-glycidoxypropyl) methylethoxysilane, bis (γ-glycidoxypropyl) methylpropoxysilane, bis (γ-glycidoxypropyl) methylbutoxysilane, bis (γ- Glycidoxypropyl) methylphenoxysilane, tris (γ-glycidoxypropyl) methoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ- Methacryloxyethyl triethoxy Emissions, bis (.gamma.-methacryloxypropyl) dimethoxysilane, tris (.gamma.-methacryloxypropyl) include silane.

  Furthermore, for example, β- (3,4-epoxycyclohexyl) ethyl-trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-triethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-tri Propoxysilane, β- (3,4-epoxycyclohexyl) ethyl-tributoxysilane, β- (3,4-epoxycyclohexyl) ethyl-triphenoxysilane, β- (3,4-epoxycyclohexyl) propyl-trimethoxysilane Β- (3,4-epoxycyclohexyl) ethyl-methyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-ethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-ethyldiethoxysilane, β- (3,4-epoxycyclohexyl) Le - and methyl diethoxy silane.

  Further, for example, β- (3,4-epoxycyclohexyl) ethyl-methyldipropoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldibutoxysilane, β- (3,4-epoxycyclohexyl) ethyl- Methyldiphenoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethylmethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-diethylethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethyl Ethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethylpropoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethylbutoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethylphenoxysilane , Β- (3,4-epoxy Cyclohexyl) ethyl - diethyl methoxysilane, beta-(3,4-epoxycyclohexyl) ethyl - and methyl-diisopropenylbenzene pen silane.

  Further, for example, 2,2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2,2-diethoxy-1- (3-triethoxysilylpropyl) -1- Aza-2-silacyclopentane, 2,2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-silacyclohexane, 2,2-dimethoxy-1- (5-trimethoxysilylpentyl) -1-aza-2-silacycloheptane, 2,2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2,2-diethoxy-1- (3-di Ethoxyethylsilylpropyl) -1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1- (3-trimethoxysilylpropyl) -1-aza-2- Lacyclopentane, 2-ethoxy-2-ethyl-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-methoxy-2-methyl-1- (3-dimethoxymethylsilylpropyl) ) -1-Aza-2-silacyclopentane, 2-ethoxy-2-ethyl-1- (3-diethoxyethylsilylpropyl) -1-aza-2-silacyclopentane, 1,4-bis [3- (Trimethoxysilyl) propyl] piperazine, 1,4-bis [3- (triethoxysilyl) propyl] piperazine, 1,4-bis [3- (dimethoxymethylsilyl) propyl] piperazine, 1,3-bis [3 -(Trimethoxysilyl) propyl] imidazolidine, 1,3-bis [3- (triethoxysilyl) propyl] imidazolidine, 1,3-bis [3 (Diemethoxyethylsilyl) propyl] imidazolidine, 1,3-bis [3- (trimethoxysilyl) propyl] hexahydropyrimidine, 1,3-bis [3- (triethoxysilyl) propyl] hexahydropyrimidine, 1 , 3-bis [3- (tributoxysilyl) propyl] -1,2,3,4-tetrahydropyrimidine, bis (3-triethoxysilylpropyl) methylamine, bis (3-triethoxysilylpropyl) ethylamine, bis (3-triethoxysilylpropyl) propylamine, bis (3-triethoxysilylpropyl) butylamine, bis (3-triethoxysilylpropyl) phenylamine, bis (3-triethoxysilylpropyl) benzylamine, bis (triethoxy Silylmethyl) methylamine, bis (2 -Triethoxysilylethyl) methylamine, bis (triethoxysilylmethyl) propylamine, bis (2-triethoxysilylethyl) propylamine, bis (3-trimethoxysilylpropyl) N-trimethylsilylamine, bis (3-tri Ethoxysilylpropyl) N-trimethylsilylamine, bis (2-triethoxysilylethyl) N-trimethylsilylamine compound, tris (triethoxysilylmethyl) amine, tris (2-triethoxysilylethyl) amine, tris (3-triethoxy Silylpropyl) amine and trimethoxysilyl compounds corresponding to these triethoxysilyl compounds, 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3- (diethoxyethylsilyl) propyl] -4 Methylpiperazine, 1- [3- (trimethoxysilyl) propyl] -3-methylimidazolidine, 1- [3- (diethoxyethylsilyl) propyl] -3-ethylimidazolidine, 1- [3- (triethoxy) Silyl) propyl] -3-methylhexahydropyrimidine, 1- [3- (dimethoxymethylsilyl) propyl] -3-methylhexahydropyrimidine, 3- [3- (tributoxysilyl) propyl] -1-methyl-1 , 2,3,4-tetrahydropyrimidine, 3- [3- (dimethoxymethylsilyl) propyl] -1-ethyl-1,2,3,4-tetrahydropyrimidine, 1- (2-ethoxyethyl) -3- [ 3- (trimethoxysilyl) propyl] imidazolidine, (2- {3- [3- (trimethoxysilyl) propyl] tetrahydride Pyrimidin-1-yl} ethyl) dimethylamine, 1- [3- (triethoxysilyl) propyl] -4- (trimethylsilyl) piperazine, 1- [3- (dimethoxymethylsilyl) propyl] -4- (trimethylsilyl) piperazine 1- [3- (Tributoxysilyl) propyl] -4- (trimethylsilyl) piperazine, 1- [3- (diethoxyethylsilyl) propyl] -3- (triethylsilyl) imidazolidine, 1- [3- ( Triethoxysilyl) propyl] -3- (trimethylsilyl) imidazolidine, 1- [3- (dimethoxymethylsilyl) propyl] -3- (trimethylsilyl) hexahydropyrimidine, 1- [3- (triethoxysilyl) propyl]- 3- (trimethylsilyl) hexahydropyrimidine, 1- [4- (tri Ethoxysilyl) butyl] -4- (trimethylsilyl) piperazine and the like. Furthermore, for example, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N, N′-dimethylpropylene urea, N-methylpyrrolidone and the like can be mentioned.

  Furthermore, examples of the modifier include 4.4-bis (dimethylamino) benzophenone.

  Among them, 1,3-dimethyl-2-imidazolidinone, tetraglycidyl-1,3-bisaminomethylcyclohexane, 3- (4-methylpiperazin-1-yl) propyltriethoxysilane, 4.4-bis (dimethyl) Amino) benzophenone and the like are preferable.

  By reacting the above modifier with a conjugated diene polymer, a functional group selected from a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, an alkoxysilane group, a carboxyl group, an acid anhydride group, and an isocyanate group is produced. A modified conjugated diene polymer in which a residue of a modifying agent containing at least one atomic group is bonded is obtained.

  The amount of the above modifier used is preferably more than 0.5 equivalent, less than 1.0 equivalent, more preferably more than 0.7 equivalent, more than 5 equivalent, with respect to 1 equivalent of living terminal of the conjugated diene polymer. Hereinafter, more preferably more than 1 equivalent and 4 equivalents or less. In the present embodiment, the living terminal amount of the conjugated diene polymer may be calculated from the amount of the organic lithium compound used for the polymerization and the number of lithium atoms bonded to the organic lithium compound. Alternatively, it may be calculated from the number average molecular weight of the obtained conjugated diene polymer.

  The above modifiers may be used alone or in combination of two or more.

(Method for producing modified conjugated diene polymer (a), etc.)
By reacting the active terminal of the conjugated diene polymer obtained by the above-described polymerization method with the above-described modifier, the modified conjugated diene-based polymer (a) (hereinafter also referred to as “component (a)”). A solution is obtained. You may add a reaction terminator to this polymer solution as needed. Examples of the reaction terminator include alcohols such as methanol, ethanol and propanol; organic acids such as stearic acid, lauric acid and octanoic acid; water and the like.

  Further, after the modification reaction of the conjugated diene polymer, the metals contained in the polymer may be deashed as necessary. As a deashing method, for example, a method is used in which water, an organic acid, an inorganic acid, an oxidizing agent such as hydrogen peroxide is brought into contact with a polymer solution to extract metals, and then the aqueous layer is separated. .

  Furthermore, after the modification reaction of the conjugated diene polymer, an antioxidant may be added to the polymer solution. Examples of the antioxidant include phenol-based stabilizers, phosphorus-based stabilizers, sulfur-based stabilizers and the like.

  As a method for obtaining the component (a) from the polymer solution, a conventionally known method can be applied. For example, after separating the solvent by steam stripping or the like, the polymer is separated by filtration, further dehydrated and dried to obtain the polymer, concentrated in a flushing tank, and further devolatilized by a vent extruder or the like. A method, a method of directly devolatilizing with a drum dryer or the like can be applied.

  The weight average molecular weight (polystyrene conversion) of the component (a) used in the present embodiment is preferably 100,000 to 2,000,000, more preferably 150,000 to 1,000,000 in consideration of processability and physical properties. The weight average molecular weight can be determined from a calibration curve using standard polystyrene by measuring a chromatogram using GPC using a column having a polystyrene gel as a filler.

  When the conjugated diene polymer before modification of component (a) is polybutadiene, the proportion of vinyl bonds in the conjugated diene bond unit of the conjugated diene polymer before modification is 10% by mass to 80% by mass. % Is preferred. In order to improve rolling resistance performance and wear resistance, it is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less. At this time, the mass ratio of the cis bond to the trans bond in the conjugated diene bond unit is preferably cis bond / trans bond = 1 / 1.1 to 1.5.

(Rubber polymer (b) component other than modified conjugated diene polymer (a))
The component (b) other than the modified conjugated diene polymer (a) will be described. In the rubber component (A) used in the present embodiment, a rubbery polymer (b) component other than the modified conjugated diene polymer (a) component and the modified conjugated diene polymer (a) component can be used in combination. Examples of the rubbery polymer (b) component include natural rubber; conjugated diene polymer and hydrogenated product thereof; copolymer of conjugated diene compound and vinyl aromatic compound, and hydrogenated product thereof; Examples include diene polymers. Specifically, butadiene rubber and its hydrogenated product, isoprene rubber and its hydrogenated product, styrene-butadiene copolymer and its hydrogenated product, styrene-isoprene block copolymer and its hydrogenated product, acrylonitrile-butadiene rubber And hydrogenated products thereof.

  Non-diene polymers include ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, ethylene-octene rubber and other olefin-based elastomers, butyl rubber, brominated butyl rubber, acrylic rubber Fluorine rubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylic ester-conjugated diene copolymer rubber, urethane rubber, polysulfide rubber and the like.

  These components (b) may be used alone or in combination of two or more. As the component (b), from the viewpoint of better compatibility and the purpose of achieving the intended effect, among the above, from natural rubber (B-1) and high cis polybutadiene (B-2) It is preferably at least one selected from the group consisting of The high cis polybutadiene is a polymer having a 1,4-cis bond amount of the butadiene bond unit portion of 70% or more. The amount of 1,4-cis bond can be measured with an infrared spectrophotometer.

  In the modified conjugated diene polymer composition of the present embodiment, the mass ratio of the component (a) to the component (b) is (a) / (b) = 10/90 to 90/10. It is preferably 25/75 to 80/20, more preferably 30/70 to 70/30. By setting the mass ratio of the component (a) and the component (b) in the above range, when the modified conjugated diene polymer composition is a vulcanized product, the rolling resistance performance, the wear resistance, the fracture characteristics, and the low temperature performance It can be set as the composition excellent in.

<Reinforcing filler>
The modified conjugated diene polymer composition of the present embodiment is selected from the group consisting of a silica-based inorganic filler, a metal oxide, a metal hydroxide, and carbon black with respect to 100 parts by mass of the rubber component (A). It is preferable to contain 0.5 to 200 parts by mass of at least one reinforcing filler.

(Silica-based inorganic filler)
As the silica-based inorganic filler contained in the modified conjugated diene-based polymer composition, it is preferable to use solid particles containing SiO ₂ or Si ₃ Al as a main component. Here, a main component means the component which occupies 50 mass% or more of the whole, Preferably it is a component which occupies 70 mass% or more, More preferably, it is a component which occupies 90 mass% or more.

  Specific examples of the silica-based inorganic filler include inorganic fibrous materials such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. A silica type inorganic filler may be used individually by 1 type, and may be used together 2 or more types. Moreover, the mixture of the silica type inorganic filler which hydrophobized the surface, and a silica type inorganic filler and inorganic fillers other than a silica type can also be used. Among these, silica and glass fiber are preferable, and silica is more preferable.

  As silica, dry silica, wet silica, synthetic silicate silica, and the like can be used. Among them, wet silica is preferable because it is more excellent in improving fracture characteristics and wet skid resistance performance.

In the modified conjugated diene polymer composition of the present embodiment, from the viewpoint of obtaining good wear resistance and fracture characteristics, the nitrogen adsorption specific surface area determined by the BET adsorption method of the silica-based inorganic filler is 170 to 300 m ^2. / G, more preferably 200 to 300 m ² / g.

  It is preferable that the compounding quantity of the silica type inorganic filler in the modified conjugated diene polymer composition of this Embodiment is 0.5 mass part-200 mass parts with respect to 100 mass parts of rubber components (A). The upper limit of the amount of the silica-based inorganic filler based on 100 parts by mass of the rubber component (A) is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 75 parts by mass or less. The lower limit is preferably 0.5 parts by mass or more, more preferably 5 parts by mass or more, further preferably 20 parts by mass or more, and particularly preferably 35 parts by mass or more. When the blending amount of the silica-based inorganic filler is within the above range, the effect of adding the filler is expressed, the dispersibility of the silica-based inorganic filler is improved, and the processability of the resulting composition is improved, And mechanical strength is improved.

(Carbon black)
Carbon black may be added to the modified conjugated diene polymer composition of the present embodiment as a reinforcing filler other than the silica inorganic filler.

As carbon black, for example, carbon black of each class such as SRF, FEF, HAF, ISAF, and SAF can be used. From the viewpoint of excellent reinforcing effect, carbon black having a nitrogen adsorption specific surface area of 50 m ² / g or more and a DBP (dibutyl phthalate) oil absorption of 80 mL / 100 g is preferred.

  The compounding amount of carbon black is preferably 0.5 part by mass to 200 parts by mass, more preferably 3 parts by mass to 100 parts by mass with respect to 100 parts by mass of the rubber component (A), and 5 parts by mass to 50 parts by mass. Part is more preferred.

(Metal oxide and metal hydroxide)
In addition to the silica-based inorganic filler and carbon black, a metal oxide or a metal hydroxide may be added to the modified conjugated diene polymer composition of the present embodiment. The metal oxide is preferably solid particles having a chemical formula MxOy (M represents a metal atom, and x and y each represents an integer of 1 to 6) as a main component. Here, a main component means the component which occupies 50 mass% or more of the whole, Preferably it is a component which occupies 70 mass% or more, More preferably, it is a component which occupies 90 mass% or more.

  As the metal oxide, for example, alumina, titanium oxide, magnesium oxide, zinc oxide, or the like can be used. Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, zirconium hydroxide and the like. A metal oxide and a metal hydroxide may be used individually by 1 type, and may be used together 2 or more types. Moreover, a mixture with inorganic fillers other than a metal oxide and a metal hydroxide can also be used.

<(B) Carbon nanofiber>
Examples of (B) carbon nanofibers used in the present embodiment include so-called carbon nanotubes. Carbon nanotubes have a single-layer structure in which graphene sheets with carbon hexagonal mesh surfaces are closed in a cylindrical shape, or a multilayer structure in which these cylindrical structures are arranged in a nested manner. That is, the carbon nanotube may be composed of only a single-layer structure or a multilayer structure, and the single-layer structure and the multilayer structure may be mixed. A carbon material partially having a carbon nanotube structure can also be used. In addition to the name “carbon nanotube”, it may be called “graphite fibril nanotube”. Single-wall carbon nanotubes or multi-wall carbon nanotubes are manufactured to a desired size by an arc discharge method, a laser ablation method, a vapor phase growth method, or the like. The arc discharge method is a method of obtaining multi-walled carbon nanotubes deposited on a cathode by performing an arc discharge between electrode materials made of carbon rods in an argon or hydrogen atmosphere at a pressure slightly lower than atmospheric pressure. In addition, the single-walled carbon nanotube is obtained by mixing the carbon rod with a catalyst such as nickel / cobalt to cause arc discharge and adhering to the inner surface of the processing vessel. The laser ablation method melts and evaporates the carbon surface by irradiating a strong YAG laser pulsed laser beam onto a carbon surface mixed with a target catalyst such as nickel / cobalt in a rare gas (eg argon). This is a method for obtaining single-walled carbon nanotubes. The vapor phase growth method is a method in which hydrocarbons such as benzene and toluene are thermally decomposed in the gas phase to synthesize carbon nanotubes. More specifically, a fluid catalyst method, a zeolite supported catalyst method, and the like can be exemplified. (B) Before the carbon nanofibers are kneaded with the (A) rubber component, surface treatment, for example, ion implantation treatment, sputter etching treatment, plasma treatment, etc. is performed in advance, so that the (A) rubber nanofiber is bonded to the carbon nanofiber. And wettability can be improved.

  The carbon nanofiber (B) contained in the modified conjugated diene polymer composition of the present embodiment has an average diameter of 0.5 to 500 nm, preferably 0.4 to 250 nm, more preferably 1 to 150 nm. is there. (B) When the average diameter of the carbon nanofibers is within the above range, (B) the carbon nanofibers are well dispersed without being agglomerated during the kneading with the rubber component. Fibers are less likely to be crushed.

  In addition, the average diameter of (B) carbon nanofiber can be confirmed from the image obtained, for example with the electron microscope.

  The content of (B) carbon nanofibers in the modified conjugated diene polymer composition is 1 to 40 parts by mass with respect to 100 parts by mass of the rubber component (A). (B) When the content of the carbon nanofiber is within the above range, the effect of improving the reinforcing property can be sufficiently obtained, the low heat build-up property is good, and the cost is preferable.

  (B) A carbon nanofiber may be used individually by 1 type, and may be used together 2 or more types.

(Silane coupling agent)
In the modified conjugated diene polymer composition of the present embodiment, a silane coupling agent may be contained. The silane coupling agent has a function to close the interaction between the rubber component and the silica-based inorganic filler, and has an affinity or binding group for each of the rubber component and the silica-based inorganic filler. ing.

  Specific examples of the silane coupling agent include bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (tri Ethoxysilyl) -ethyl] -tetrasulfide and the like.

  The blending amount of the silane coupling agent is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and 1 part by mass with respect to 100 parts by mass of the silica-based inorganic filler described above. -15 mass parts is further more preferable. By making the compounding quantity of a silane coupling agent into the said numerical range, while being able to acquire sufficient compounding effect, it can make economical efficiency favorable.

<Method for Producing Modified Conjugated Diene Polymer Composition>
The modified conjugated diene polymer composition of the present embodiment can be produced by mixing the above components.

  The method of mixing (A) the rubber component, (B) the carbon nanofiber, and, if necessary, the silica-based inorganic filler and other fillers and the silane coupling agent is not particularly limited. For example, a melt kneading method using a general blender such as an open roll, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, a multi-screw extruder, etc. The method of removing by heating, etc. are mentioned. Of these, a melt kneading method using a roll, a Banbury mixer, a kneader, or an extruder is preferred from the viewpoint of productivity and good kneading properties. Moreover, any of the method of kneading a rubber component and various compounding agents at a time and the method of mixing in a plurality of times can be applied.

(Bound rubber amount)
The amount of bound rubber in the modified conjugated diene polymer composition of the present embodiment is preferably 20% by mass or more.

  The amount of bound rubber in the modified conjugated diene polymer composition (rubber composition) after completion of the kneading is preferably 20% by mass or more, more preferably 30% by mass or more from the viewpoint of improving wear resistance and fracture strength. More preferred.

  In the present embodiment, the bound rubber amount can be measured by the method described in the examples described later.

(Vulcanizing agent)
The modified conjugated diene polymer composition of the present embodiment may be a vulcanized composition that has been vulcanized with a vulcanizing agent. As the vulcanizing agent, for example, radical generators such as organic peroxides and azo compounds, oxime compounds, nitroso compounds, polyamine compounds, sulfur and sulfur compounds can be used. Sulfur compounds include sulfur monochloride, sulfur dichloride, disulfide compounds, polymeric polysulfur compounds, and the like.

  Although the usage-amount of a vulcanizing agent is not specifically limited, It is preferable that it is 0.01 mass part-20 mass parts with respect to 100 mass parts of rubber components (A) containing a modified conjugated diene polymer, 0.1 mass Part-15 mass parts is more preferable. As a vulcanization method, a conventionally known method can be applied, and the vulcanization temperature is preferably, for example, 120 ° C to 200 ° C, and more preferably 140 ° C to 180 ° C.

(Vulcanization accelerator, vulcanization aid)
In vulcanization, a vulcanization accelerator may be used as necessary. As the vulcanization accelerator, conventionally known materials can be used. For example, sulfenamide, guanidine, thiuram, aldehyde-amine, aldehyde-ammonia, thiazole, thiourea, dithiocarbamate And the like. As the vulcanization aid, zinc white, stearic acid or the like can be used.

  Although the usage-amount of a vulcanization accelerator is not specifically limited, It is preferable that it is 0.01-20 mass parts with respect to 100 mass parts of rubber components (A) containing a modified conjugated diene polymer. 1 mass part-15 mass parts are more preferable.

(Rubber softener)
In order to improve processability, the modified conjugated diene polymer composition of the present embodiment may be blended with a rubber softener. As the rubber softener, mineral oil, liquid or low molecular weight synthetic softener is suitable.

  A mineral oil-based rubber softener, called process oil or extender oil, used to improve rubber softening, volume increase, and processability is a mixture of aromatic rings, naphthene rings, and paraffin chains. A paraffin chain having 50% or more carbon atoms in the total carbon is called paraffinic, a naphthene ring having 30 to 45% carbon is naphthenic, and an aromatic carbon having more than 30% aromatic is aromatic. It is called a system. The rubber softener used in the present embodiment is preferably a naphthenic and / or paraffinic one.

  The blending amount of the rubber softener is not particularly limited, but is preferably 10 to 80 parts by mass, and 20 to 50 parts by mass with respect to 100 parts by mass of the rubber component (A) containing the modified conjugated diene polymer. More preferred.

(Other additives)
The modified conjugated diene polymer composition of the present embodiment includes softeners and fillers other than those described above, as well as a heat stabilizer, an antistatic agent, and a weather stabilizer, as long as the purpose of the present embodiment is not impaired. Various additives such as an anti-aging agent, a coloring agent, and a lubricant may be used. Specific examples of the filler include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. Examples of the softening agent blended as necessary to adjust the hardness and fluidity of the target product include liquid paraffin, castor oil, and linseed oil. Known materials can be applied as the heat resistance stabilizer, antistatic agent, weather resistance stabilizer, anti-aging agent, colorant, and lubricant.

<Application>
The above modified conjugated diene polymer composition is composed of silica inorganic filler, carbon black, other reinforcing filler, silane coupling agent, vulcanizing agent, vulcanization accelerator, vulcanization aid, rubber softener. It can be set as the composition for tires containing various compounding agents, such as.

  The tire composition of the present embodiment includes the above-described modified conjugated diene polymer composition.

  The tire composition of the present embodiment can be made into a tire by vulcanization molding according to a conventional method.

  The tire of the present embodiment includes the above-described tire composition. Further, the tire sidewall composition of the present embodiment includes the tire composition described above. Furthermore, the tire sidewall of the present embodiment includes the above-described tire sidewall composition.

  Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited thereto. In addition, the analysis of the sample in a manufacture example was performed by the method shown below.

(1) Mooney viscosity According to JIS K 6300, preheating was performed at 100 ° C. for 1 minute, and the viscosity after 4 minutes was measured.

(2) Modification rate Applying the property that the modified component is adsorbed on a GPC column with silica gel as a filler, using a sample solution containing a sample and standard polystyrene with a molecular weight of 5000 (polystyrene does not adsorb on the column), Both chromatograms of polystyrene-based column GPC and silica-based column GPC were measured using an RI detector, and the amount of adsorption on the silica-based column was measured from the difference between them to determine the modification rate. Tetrahydrofuran (THF) was used as the eluent for both GPC of the polystyrene column and GPC of the silica column.

<Polystyrene type>
Guard column: Tosoh, “TSKguardcolumn HHR-H”
Column: manufactured by Tosoh Corporation, “TSKgel G6000HHR”, “TSKgel G5000HHR”, “TSKgel G4000HHR”
GPC: “HLC8020” manufactured by Tosoh Corporation
Analysis conditions: oven temperature 40 ° C., THF flow rate 1.0 mL / min.

<Silica-based>
Guard column: “DIOL” (4.6 × 12.5 mm 5 micron)
Column: “Zorbax PSM-1000S”, “Zorbax PSM-300S”, “Zorbax PSM-60S” manufactured by Agilent Technologies
GPC: manufactured by Tosoh Corporation, “CCP8020 series build-up type GPC system” (autosampler “AS-8020”, degasser “SD-8022”, pump “CCPS”, column oven “CO-8020”, differential refractometer “RI-8021” )) Analytical conditions: oven temperature 40 ° C., THF flow rate 0.5 mL / min.

  A sample of 10 mg was dissolved in 20 mL of THF together with 5 mg of standard polystyrene to prepare a solution. 200 μL of the solution was injected into GPC and the chromatogram was measured. The total peak area of the chromatogram using the polystyrene column is 100, the sample peak area is “P1”, the peak area of the standard polystyrene is “P2”, and the peak area of the chromatogram using the silica column is With the total as 100, the sample peak area was “P3”, the peak area of standard polystyrene was “P4”, and the modification rate (%) was calculated by the following formula.

    Denaturation rate (%) = [1- (P2 × P3) / (P1 × P4)] × 100

(Preparation of polyfunctional anionic polymerization initiator)
The autoclave having an internal volume of 10 L and equipped with a stirrer and a jacket was washed and dried, and purged with nitrogen. Thereafter, 1,3-butadiene, cyclohexane, tetrahydrofuran (THF) and divinylbenzene (DVB) subjected to drying treatment under the conditions shown in Table 1 below were added to the autoclave, and then n-butyllithium (NBL) was added. Then, the reaction was carried out at 75 ° C. for 1 hour to prepare a polyfunctional anionic polymerization initiator. The prepared polyfunctional anionic polymerization initiator was soluble in cyclohexane and no gel was observed.

  For the preparation of the polyfunctional anionic polymerization initiator, a divinylbenzene mixture (manufactured by Nippon Steel Chemical Co., Ltd.) containing m-divinylbenzene, p-divinylbenzene, ethylvinylbenzene and the like and having a divinylbenzene concentration of 57% by mass was used. In addition, since the said commercially available divinylbenzene is a mixture, the amount of divinylbenzene in the following Table 1 is a pure amount of divinylbenzene converted excluding the content of impurities.

[Production Example 1]
An autoclave having an internal volume of 10 L and equipped with a stirrer and a jacket and capable of temperature control was used as a reactor. 897 g of butadiene from which impurities had been previously removed, 315 g of styrene, 6346 g of cyclohexane, and 0.017 g of 2,2-bis (2-oxolanyl) propane as a polar compound were charged into the reactor, and the temperature in the reactor was maintained at 55 ° C. The polyfunctional anionic polymerization initiator prepared as described above was supplied to the reactor so that the addition amount of lithium was 10.5 mmol, and the reaction was started. After the start of the reaction, the temperature in the reactor started to rise due to the exotherm due to polymerization, and the final temperature in the reactor reached 84 ° C. After completion of the polymerization reaction, 5.25 mmol of 1,3-dimethyl-2-imidazolidinone as a modifier is added to the reactor, and a modification reaction is performed at a temperature of 83 ° C. for 5 minutes to obtain a polymer solution. It was.

  After 2.1 g of an antioxidant (2,6-di-tert-butyl-p-cresol: BHT) was added to this polymer solution, the solvent was removed by steam stripping, and a drying treatment was performed using a dryer. A styrene-butadiene random copolymer (sample (i)) having a modifying component was obtained. The analysis results of sample (i) are shown in Table 2 below.

[Production Example 2]
A styrene-butadiene random copolymer (sample) having a modifying component in the same manner as in Production Example 1 except that 10.5 mmol of tetraglycidyl-1,3-bisaminomethylcyclohexane was added as a modifying agent to carry out the modifying reaction. (Ii)) was obtained. The analysis results of sample (ii) are shown in Table 2 below.

[Production Example 3]
A styrene-butadiene random copolymer having a modifying component in the same manner as in Production Example 1 except that 21 mmol of 3- (4-methylpiperazin-1-yl) propyltriethoxysilane was added as a modifying agent to carry out the modifying reaction. (Sample (iii)) was obtained. The analysis results of sample (iii) are shown in Table 2 below.

[Production Example 4]
A styrene-butadiene random copolymer (sample (iv) having a modifying component was used in the same manner as in Production Example 1 except that 5.25 mmol of 4.4-bis (dimethylamino) benzophenone was added as a modifying agent and the modification reaction was carried out. )). The analysis results of sample (iv) are shown in Table 2 below.

[Production Example 5]
The initiator used for the polymerization is replaced with n-butyllithium from the polyfunctional anionic polymerization initiator, and n-butyllithium is supplied to the reactor so that the addition amount of lithium is 10.5 mmol, and 4.4 as a modifier. -A styrene-butadiene random copolymer (sample (v)) having a modifying component was obtained in the same manner as in Production Example 1 except that 5.25 mmol of bis (dimethylamino) benzophenone was added and the modification reaction was carried out. The analysis results of the sample (v) are shown in Table 2 below.

[Production Example 6]
A styrene-butadiene random copolymer having no modifying component (sample (sample)) was used in the same manner as in Production Example 1 except that the modification reaction was not carried out and the polymerization reaction was stopped with an appropriate amount of ethanol at the same timing as the modification reaction. vi)). The analysis results of sample (vi) are shown in Table 2 below.

* Modifier (1) is 1,3-dimethyl-2-imidazolidinone * Modifier (2) is tetraglycidyl-1,3-bisaminomethylcyclohexane * Modifier (3) is 3- (4-methylpiperazine -1-yl) propyltriethoxysilane * Modifier (4) is 4.4-bis (dimethylamino) benzophenone

[Example 1]
Each component such as the prepared sample (i) (hereinafter also referred to as “component (i)”) was kneaded by the following method to form a modified conjugated diene polymer composition.

  Using a closed kneader (with an internal volume of 0.3 L) equipped with a temperature control device, as the first stage of kneading, under the conditions of a filling rate of 65% and a rotor rotational speed of 50/57 rpm, the ratio shown in Table 3 Sample (i), high cis BR, filler (silica, carbon nanotube), silane coupling agent, process oil, zinc white, and stearic acid were kneaded to obtain a rubber composition. At this time, the temperature of the closed kneader was controlled, and the discharge temperature (formulation) was adjusted to 155 ° C to 160 ° C.

  Next, as the second stage kneading, the rubber composition obtained in the first stage kneading is cooled to room temperature and then added with an anti-aging agent in the proportions shown in Table 3 to improve the dispersion of silica. The rubber composition was obtained by kneading again. Also in this case, the discharge temperature (formulation) was adjusted to 155 ° C to 160 ° C by controlling the temperature of the kneader.

  In the third stage of kneading, the rubber composition obtained in the second stage of kneading was cooled to room temperature and then kneaded with an open roll set at 70 ° C. with sulfur and a vulcanization accelerator.

  The rubber composition obtained by the third kneading was molded and vulcanized with a vulcanizing press at 160 ° C. for 20 minutes to obtain a modified conjugated diene polymer composition. The physical properties of the resulting modified conjugated diene polymer composition were measured. The measurement results are shown in Table 3 below.

  The physical properties of the modified conjugated diene polymer composition were measured by the following methods.

<Bound rubber amount>
About 0.2 g of the rubber composition after completion of the second stage kneading step was cut into a square of about 1 mm to prepare a test piece. The test piece was placed in a Harris basket (100 mesh wire mesh) and the weight was measured. Then, after immersing a test piece in toluene for 24 hours, the drying process was performed and the weight was measured. The amount of rubber bonded to the filler was calculated from the amount of the non-dissolved component, and the ratio of rubber bonded to the filler (bound rubber amount) was obtained.

<Tear strength>
Based on JIS K6252, it measured in a 23 degreeC thermostat, and the measured value of the modified conjugated diene polymer composition obtained by the comparative example 1 was set to 100, and was indexed. Larger values indicate better tear strength.

<Tensile strength>
Measured by the tensile test method of JIS K6251 and indexed with the measured value of the modified conjugated diene polymer composition obtained in Comparative Example 1 as 100. The larger the index value, the better the tensile strength.

<Abrasion resistance>
Using an Akron abrasion tester, the amount of wear at a load of 6 pounds and 1000 revolutions was measured, and the measured value of the modified conjugated diene polymer composition obtained in Comparative Example 1 was taken as 100 and indexed. It shows that it is excellent in abrasion resistance, so that an index value is large.

<Viscoelastic parameters>
Measurement of the modified conjugated diene polymer composition obtained in Comparative Example 1 using a viscoelasticity tester (ARES) manufactured by Rheometrics Scientific, Inc., and measuring the viscoelasticity parameter (tan δ) in the torsion mode. The value was set to 100 and indexed.

  Tan δ measured at 50 ° C., frequency 10 Hz, and strain 3% was used as an index of rolling resistance performance (fuel saving characteristics). The larger the index value, the better the rolling resistance performance (fuel saving performance).

[Examples 2 to 11 and Comparative Examples 1 to 6]
A modified conjugated diene polymer composition was produced in the same manner as in Example 1 except that each component was kneaded at the blending ratio shown in Table 3, and the physical properties of the modified conjugated diene polymer composition were evaluated. The respective evaluation results are shown in Table 3.

[note]
1) High cis BR (high cis polybutadiene): BR150 manufactured by Ube Industries, Ltd.
2) NR (natural rubber): RSS No. 3 3) Silica: manufactured by Degussa, trade name “Ultra Gil VN3”
4) Carbon Black: Product name “Seast KH” manufactured by Tokai Carbon Co., Ltd.
5) Carbon nanotube 1: VGCF-S manufactured by Showa Denko (multi-walled carbon nanotube having an average diameter of about 90 nm)
6) Carbon nanotube 2: VGCF-X manufactured by Showa Denko (multi-walled carbon nanotube having an average diameter of about 9 nm)
7) Carbon nanotube 3: Multi-walled carbon nanotube having an average diameter of about 600 nm 8) Silane coupling agent: Product name “Si69” manufactured by Degussa
9) Process oil: Product name “NC140” manufactured by Japan Energy
10) Anti-aging agent: N-isopropyl-N-phenyl-p-phenylenediamine 11) Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazylsulfenamide 12) Vulcanization accelerator 2: Diphenylguanidine Carbon The average diameters of the nanotubes 1, 2 and 3 were confirmed from images obtained with an electron microscope.

  As shown in Table 3 above, NR or high cis BR is blended with a modified conjugated diene polymer polymerized with a polyfunctional anionic polymerization initiator, and a specific amount of carbon nanofibers having a specific average diameter is blended as a filler. Thus, it was found that the obtained modified conjugated diene polymer composition can greatly improve the wear resistance, tear strength, and tensile strength while maintaining low rolling resistance. From these characteristics, the modified conjugated diene polymer composition of the present embodiment is suitable for a sidewall portion of a tire.

  The modified conjugated diene polymer composition of the present invention is excellent in the balance of physical properties such as rolling resistance performance, abrasion resistance, and fracture strength, so that not only the tire sidewall portion but also each tire portion, automobile interior / exterior product, There is a possibility of industrial use in a wide range of fields including fields such as anti-vibration rubber, belts, footwear, foams, and various industrial parts.

Claims (10)

(A) A conjugated diene polymer having a polymerization active terminal obtained by polymerizing a conjugated diene compound or copolymerizing a conjugated diene compound and an aromatic vinyl compound using a polyfunctional anionic polymerization initiator, Modified conjugated diene polymer (a) obtained by reacting a modifier having a functional group capable of reacting at the polymerization active terminal of the conjugated diene polymer: 10 to 90% by mass, and modified conjugated diene polymer (a) 100 parts by mass of a rubber component containing 10 to 90% by mass of a rubbery polymer (b) other than
(B) Carbon nanofibers having an average diameter of 0.5 to 500 nm: 1 to 40 parts by mass,
A modified conjugated diene polymer composition comprising:   The modified conjugated diene according to claim 1, comprising 0.5 to 200 parts by mass of at least one reinforcing filler selected from the group consisting of a silica-based inorganic filler, a metal oxide, a metal hydroxide, and carbon black. -Based polymer composition.   The functional group capable of reacting with the polymerization active terminal of the conjugated diene polymer is selected from the group consisting of a hydroxyl group, an epoxy group, an amino group, an imino group, a silanol group, an alkoxysilane group, a carboxyl group, an acid anhydride group, and an isocyanate group. The modified conjugated diene polymer composition according to claim 1, wherein the modified conjugated diene polymer composition is at least one functional group. The modified conjugated diene polymer is a modified conjugated diene polymer to which at least one atomic group selected from the group consisting of the following formulas (1) to (16) is bonded. The modified conjugated diene polymer composition according to any one of the above.
(In the above formulas (1) to (16),
N represents a nitrogen atom, Si represents a silicon atom, O represents an oxygen atom, C represents a carbon atom, H represents a hydrogen atom,
R ¹ and R ² each independently represent a hydrogen atom or a linear or cyclic hydrocarbon group having 1 to 24 carbon atoms, and each of the hydrocarbon groups independently represents a hydroxyl group, an epoxy group, an amino group, carbon It may have at least one functional group selected from the group consisting of an imino group having a hydrocarbon group of 1 to 24, a silanol group and an alkoxysilane group of 1 to 24 carbon atoms,
R ³ each independently represents a linear or cyclic hydrocarbon group having 1 to 48 carbon atoms, and each hydrocarbon group independently represents a hydroxyl group, an epoxy group, an amino group, or a carbon atom having 1 to 24 carbon atoms. It may have at least one functional group selected from the group consisting of an imino group having a hydrogen group, a silanol group and an alkoxysilane group having 1 to 24 carbon atoms,
Each R ⁴ independently represents a hydrogen atom or a linear or cyclic hydrocarbon group having 1 to 24 carbon atoms;
n and m are each independently 1 or 2. )   The modified conjugated diene polymer composition according to any one of claims 1 to 4, wherein the amount of bound rubber in the modified conjugated diene polymer composition is 20% by mass or more.   The modified conjugated diene polymer composition according to any one of claims 1 to 5, wherein the component (b) is at least one selected from the group consisting of natural rubber and high cis polybutadiene.   A tire composition comprising the modified conjugated diene polymer composition according to any one of claims 1 to 6.   A tire sidewall composition comprising the tire composition according to claim 7.   A tire comprising the tire composition according to claim 7.   A tire sidewall comprising the tire sidewall composition according to claim 8.