JP2011219699A - Modified conjugated diene-based rubber composition and method for producing modified conjugated diene-based rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modified conjugated diene polymer which is excellent in affinity with various inorganic fillers, such as a silica-based inorganic filler, and is excellent in balance of wet skid characteristics and low hysteresis loss properties when using the polymer as a vulcanizate, and satisfies substantially sufficient abrasion resistance and fracture strength.SOLUTION: The invention relates to the modified conjugated diene polymer which has silyl groups substituted by one or more alkoxy groups and one or more nitrogen atoms at terminals of a conjugated diene polymer, which is obtained by reacting a compound having one or more nitrogen atoms with the silyl groups substituted by two or more alkoxy groups at polymerization active terminals of a conjugated diene-based copolymer obtained by polymerizing the conjugated diene compound or copolymerizing the conjugated diene compound with an aromatic vinyl compound using a polyfunctional anionic polymerization initiator which is prepared at a molar ratio of a polyvinyl aromatic compound and lithium (polyvinyl aromatic compound/lithium) of 0.05 to 1.0.

Description

The present invention relates to a rubber composition containing a modified conjugated diene-based (co) polymer and a method for producing a modified conjugated diene-based rubber composition.
Specifically, it includes a modified conjugated diene polymer that is polymerized with a specific polyfunctional initiator and modified with a compound having a polymerization active terminal in the molecule having two or more tertiary amino groups and one or more alkoxysilyl groups. The present invention relates to a modified conjugated diene rubber composition and a method for producing a modified conjugated diene rubber composition.

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, there has been a demand for the development of a material having low rolling resistance as a material for automobile tires, particularly tire treads in contact with the ground.
On the other hand, from the viewpoint of safety, development of materials having excellent wet skid resistance and practically sufficient wear resistance and fracture characteristics is required.
Conventionally, carbon black, silica, and the like have been used as reinforcing fillers for tire treads.
Use of silica has an advantage that low hysteresis loss and wet skid resistance can be improved.
However, on the other hand, the hydrophilic surface of silica has a disadvantage that its affinity with conjugated diene rubber is low and its dispersibility is poor compared to carbon black. Therefore, in order to improve dispersibility or to provide a bond between silica and rubber, a silane coupling agent must be added separately.
Furthermore, in recent years, the dispersibility of silica in rubber materials has been improved by introducing functional groups having affinity and reactivity with silica at the end of rubber molecules having high mobility. Attempts have been made to reduce hysteresis loss by sealing the part with a bond with silica particles.

For example, conventionally, a modified diene rubber obtained by reacting a modifier having a glycidylamino group with a polymer end (see Patent Document 1) or a glycidoxyalkoxysilane obtained by reacting with a polymer end. Modified diene rubbers (see Patent Document 2), modified diene rubbers obtained by reacting alkoxysilanes containing amino groups with polymer ends (see Patent Documents 3 and 4), and these Proposals have been made for compositions with silica.
In addition, the diene rubber is polymerized by 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. There has also been proposed a technique (see Patent Document 5) that improves the performance of a composition composed of silica and silica, that is, silica dispersibility and reduces hysteresis loss.

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

However, with the further increase in demand for fuel efficiency in recent years, development of a rubber composition with further reduced hysteresis loss has been required.
Therefore, in the present invention, when it is a vulcanizate containing a silica-based inorganic filler, it has an excellent balance between low hysteresis loss and wet skid resistance, and satisfies practically sufficient wear resistance and fracture strength. A modified conjugated diene polymer composition and a method for producing the same are provided.

As a result of intensive studies to solve the above problems, the present inventors obtained a polymer by using a specific polyfunctional anionic polymerization initiator and modifying the polymerization active terminal with a compound having a specific functional group. The resulting modified conjugated diene polymer contains an inorganic filler, especially a silica-based inorganic filler, and when it is further vulcanized, it has an excellent balance between low hysteresis loss and wet skid resistance and is practically sufficient. The present inventors have found that satisfactory wear resistance and fracture strength are satisfied, and have completed the present invention.
The present invention is as follows.

[1]
(A) Using a polyfunctional anionic polymerization initiator having a molecular weight distribution measured using gel permeation chromatography (GPC) in the range of 1.2 to 3.5, a conjugated diene compound, an aromatic vinyl compound, Modified conjugated diene system obtained by reacting a compound having one or more nitrogen atoms with a silyl group substituted with two or more alkoxy groups at the active end of the resulting polymer Polymerize conjugated diene compound using copolymer and (B) polyfunctional anionic polymerization initiator whose molecular weight distribution measured using gel permeation chromatography (GPC) is in the range of 1.2 to 3.5 Then, a modified conjugated die obtained by reacting a silyl group substituted with two or more alkoxy groups with a compound having one or more nitrogen atoms at the active terminal of the obtained polymer. A modified conjugated diene rubber composition comprising a polymer.

[2]
(A) In a hydrocarbon solvent, using a polyfunctional anionic polymerization initiator prepared in a molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) in the range of 0.05 to 1.0, After copolymerizing a conjugated diene compound and an aromatic vinyl compound, the resulting polymer is reacted with a silyl group substituted with two or more alkoxy groups at the active end of the polymer and a compound having one or more nitrogen atoms. The modified conjugated diene copolymer obtained by the above and (B) In the hydrocarbon solvent, the molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) is in the range of 0.05 to 1.0. After polymerizing a conjugated diene compound using the prepared polyfunctional anionic polymerization initiator, a silyl group substituted with two or more alkoxy groups at the active terminal of the obtained polymer and one or more nitrogen atoms A modified conjugated diene rubber composition comprising a modified conjugated diene polymer obtained by reacting a compound having a child.

[3]
The compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms is a compound represented by the following general formula (1), general formula (2) or general formula (3) The modified conjugated diene rubber composition according to [1] or [2], wherein

(In the formula ^(1), a R 1, ^{R 2} are each independently a hydrocarbon group having 1 to 12 carbon ^atoms, R 3, ^{R 4} is a hydrocarbon group having 1 to 20 carbon atoms, R ⁵ , R ⁶ , R ⁷ may be a C 1-20 hydrocarbon group that contains Si, O, or N and may be substituted with an organic group having no active hydrogen. It is an integer of 3.)

(In the formula ^{(2), R 1, R} 2 are each independently an alkyl group having 1 to 20 carbon atoms, or an aryl group, ^{R 3} is an alkylene group having 1 to 20 carbon ^{atoms, R} 4, R ⁵ is a hydrocarbon group having 1 to 6 carbon atoms and has a ring structure of 5 or more members with two adjacent Ns, and R ⁶ has no hydrocarbon group having 1 to 20 carbon atoms and active hydrogen (It is a C1-C20 hydrocarbon group substituted by a hetero atom, or a 3 organic substituted silyl group, and m is an integer of 2 or 3.)

(In the formula ^(3), R 1 ^{to R} 6, m the definition, the formulas (1) and are the same, ^{R 7} is replaced with a heteroatom having no hydrocarbon group having 1 to 20 carbon atoms, an active hydrogen Or a hydrocarbon group having 1 to 20 carbon atoms, or a triorgano-substituted silyl group.

[4]
A modified conjugated diene rubber composition containing 0.5 to 300 parts by mass of a silica-based inorganic filler with respect to 100 parts by mass of a rubber component containing the modified conjugated diene rubber composition according to any one of [1] to [3] object
[5]
At a frequency of 10 Hz, strain of 0.1% and 10% of a vulcanized product of a modified conjugated diene rubber composition containing 75 parts by mass of a silica-based inorganic filler with respect to 100 parts by mass of the modified conjugated diene rubber composition. A modified conjugated diene rubber composition, wherein the measured difference in storage modulus (ΔG ′) is 0.8 MPa or less.

[6]
A polyvinyl aromatic compound and an organic lithium compound are reacted in a molar ratio of polyvinyl aromatic compound / lithium in the range of 0.05 to 1.0,
Preparing a polyfunctional anionic polymerization initiator,
(A) using the polyfunctional anionic polymerization initiator, copolymerizing a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene copolymer;
Reacting a compound having one or more nitrogen atoms with a silyl group substituted with two or more alkoxy groups at the active terminal of the conjugated diene copolymer;
(B) a step of polymerizing a conjugated diene compound using the polyfunctional anionic polymerization initiator to obtain a conjugated diene polymer;
Reacting the active terminal of the conjugated diene polymer with a compound having one or more nitrogen atoms and a silyl group substituted with two or more alkoxy groups;
The process for producing a modified conjugated diene rubber composition according to any one of [1] to [5], wherein

  According to the present invention, when it is a vulcanizate containing a silica-based inorganic filler, it has an excellent balance between low hysteresis loss and wet skid resistance, and also satisfies practically sufficient wear resistance and fracture strength. A modified conjugated diene rubber composition is provided.

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

The modified conjugated diene rubber composition in the present embodiment includes a modified conjugated diene copolymer (A) and a modified conjugated diene polymer (B).
The modified conjugated diene copolymer (A) is a polyfunctional anionic polymerization initiator prepared in a molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) in the range of 0.05 to 1.0. , A silyl group substituted with two or more alkoxy groups at the polymerization active terminal of a conjugated diene copolymer obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound, and one or more It is a modified conjugated diene copolymer obtained by reacting a compound having a nitrogen atom.
The modified conjugated diene polymer (B) uses a polyfunctional anionic polymerization initiator prepared in a molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) in the range of 0.05 to 1.0. And reacting a compound having one or more nitrogen atoms with a silyl group substituted with two or more alkoxy groups at the polymerization active terminal of the conjugated diene polymer obtained by polymerizing the conjugated diene compound. The resulting modified conjugated diene polymer.

  Production method of modified conjugated diene copolymer (A) and modified conjugated diene polymer (B) in the present embodiment (hereinafter referred to as “modified conjugated diene copolymer (A)” and “modified conjugated diene polymer ( B) "is referred to as" modified conjugated diene-based (co) polymer ".) Is obtained by reacting a polyvinyl aromatic compound and an organic lithium compound so that the molar ratio of polyvinyl aromatic compound / lithium is from 0.05 to 0.05. A step of preparing a polyfunctional anionic polymerization initiator in the range of 1.0 and the polyfunctional anionic polymerization initiator are used to copolymerize a conjugated diene compound and an aromatic vinyl compound, or polymerize a conjugated diene compound. And a step of obtaining a conjugated diene-based (co) polymer, and a low amount having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms at the active terminal of the conjugated diene-based (co) polymer. Molecular compound Comprising the step of reacting.

First, a polyfunctional anionic polymerization initiator for obtaining a conjugated diene (co) polymer before modification will be described.
A polyfunctional anionic polymerization initiator can be prepared by reacting a polyvinyl aromatic compound and an organic lithium compound.
For example, 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 a polyvinyl aromatic compound, an organolithium compound and a monovinyl aromatic A method of reacting a polyvinyl aromatic compound after reacting with an aromatic compound, a method of reacting an organolithium compound in the presence of two or three of a conjugated diene compound and / or a monovinyl aromatic compound and a polyvinyl aromatic compound, etc. Is mentioned.

The polyfunctional anionic polymerization initiator prepared as described above is used for the polymerization of a conjugated diene compound described later or a conjugated diene copolymer composed of a conjugated diene compound-aromatic vinyl compound.
In particular, 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 polyvinyl aroma. A polyfunctional anion initiator prepared by a method of reacting a monoorganolithium compound in the presence of a group compound is preferred.
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.

<Polyvinyl aromatic compound>
Examples of the polyvinyl aromatic compound used for the preparation of the polyfunctional anionic polymerization initiator include 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'-trivinylbiphenyl, 1,2 -Divinyl-3,4-dimethylbenzene, 1,5,6-trivinyl-3,7-diethylnaphthalene and the like. These may be used alone or in combination of two or more.
In particular, divinyl benzene and diisopropenyl benzene are preferable, and a mixture of these o-, m-, and p-isomers may be used. For industrial use, it is economically advantageous to use a mixture of these isomers.

<Conjugated diene compounds and monovinyl aromatic compounds>
For the preparation of the polyfunctional anionic polymerization initiator, a conjugated diene compound and / or a monoaromatic vinyl 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, Examples include 1,3-hexadiene, and 1,3-butadiene and isoprene are particularly preferable.
Examples of the monovinyl aromatic compound include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and styrene is particularly preferable.
The conjugated diene compound and / or monoaromatic vinyl compound is preferably added so that the polyfunctional anionic polymerization initiator measured by GPC has a polystyrene-equivalent weight average molecular weight in the range of 500 to 20,000. More preferably, it is added so as to be 10,000 to 10,000.

<Organic lithium compounds>
Examples of the organolithium compound used for the preparation of the polyfunctional anionic polymerization initiator include monoorganolithium such as n-butyllithium, sec-butyllithium, tert-butyllithium, n-propyllithium, iso-propyllithium, and benzyllithium. Compound; 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-2,4 Polyfunctional organolithium compounds such as 6-triethylbenzene can be mentioned. In particular, a monoorganolithium compound of n-butyllithium, sec-butyllithium, or tert-butyllithium is preferable.
<Solvent>
Examples of the solvent used for the preparation of the polyfunctional anionic polymerization initiator include aliphatic hydrocarbons such as butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatics such as benzene, toluene and xylene. Group hydrocarbons and the like.

<Lewis base>
In order to promote and stabilize the formation of a polyfunctional anionic polymerization initiator, it is effective to add a Lewis base in the system.
Examples of the Lewis base include tertiary monoamine, tertiary diamine, chain or cyclic ether.
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 -Compounds such as dimethylformamide dicyclohexyl acetal.

As the tertiary diamine, for example, N, N, N ′, N′-tetramethyldiaminomethane, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylpropane Diamine, N, N, N ′, N′-tetramethyldiaminobutane, N, N, N ′, N′-tetramethyldiaminopentane, N, N, N ′, N′-tetramethylhexanediamine, dipiperidi And compounds such as nopentane and dipiperidinoethane.
Examples of the chain ether 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, 2,2-bis (3,4, which is a cyclic ether. , 5-trimethyl-2-oxolanyl) propane is preferred.

The said Lewis base may be used independently and may be used in combination of 2 or more type.
The greater the amount of polyvinyl aromatic compound used, the greater the proportion of molecular chain ends to which functional groups are imparted by the modification reaction described later, and the affinity and reactivity with the silica-based particles described later are improved. The balance between the low hysteresis loss and the wet skid resistance in the conjugated diene polymer composition is good, and the wear resistance and fracture characteristics are improved. On the other hand, the amount of the polyvinyl aromatic compound used relative to the organolithium compound is preferably 1.0 mol or less from the viewpoint of improving the workability at the time of kneading the composition. The process Mooney viscosity can be used as an index for processability. When the compound Mooney viscosity is too high, adverse effects such as an increase in torque at melting and an increase in power consumption occur. Further, it may be difficult to produce a uniform sheet in the sheeting process after kneading. In general, when the low hysteresis loss is improved, the Mooney viscosity of the compound tends to increase and the processability tends to deteriorate, but it is practically important not to make it too high. From these balances, the amount of the polyvinyl aromatic compound is preferably in the range of 0.05 to 1.0 mol with respect to 1 mol of the organic lithium compound, 0.1 to 0.5 mol, 0.1 to 0.45, The range of 0.1 to 0.4 mol is more preferable.

Moreover, when adding a Lewis base when preparing a polyfunctional anionic polymerization initiator, it is preferable to add within a range of 30 to 50,000 ppm with respect to the solvent used when preparing the polymerization initiator, It is preferable to add in the range of 200 to 20,000 ppm. Addition of 30 ppm or more is preferable in order to fully express the effect of promoting and stabilizing the reaction, ensuring the degree of freedom of microstructure adjustment in the subsequent polymerization step, and recovering and purifying the solvent after polymerization In consideration of separation from the polymerization solvent in, it is preferably added at 50,000 ppm or less.
The temperature for preparing the polyfunctional anionic polymerization initiator is preferably in the range of 10 ° C to 140 ° C, and more preferably in the range of 35 ° C to 110 ° C.
From the viewpoint of productivity, it 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 anionic polymerization initiator depends on the reaction temperature, but is in the range of 5 minutes to 24 hours.

The weight average molecular weight (Mw) in terms of polystyrene measured by GPC of the polyfunctional anionic polymerization initiator prepared by the method of the present invention is in the range of 500 to 20,000, preferably 1,000 to 10,000. It is.
The molecular weight distribution is in the range of (Mw / Mn) 1.2 to 3.5, preferably in the range of 1.2 to 2.5. A modified polymer composition containing a polymer obtained by using a polyfunctional anionic polymerization initiator having a molecular weight distribution within this range has a reduced Mooney viscosity and a balance between low hysteresis loss and wet skid resistance. Is an excellent vulcanizate.

The modified conjugated diene-based (co) polymer of the present invention is obtained by (co) polymerizing a conjugated diene compound and an aromatic vinyl compound or polymerizing a conjugated diene compound using the above-described polyfunctional anionic polymerization initiator. Then, it is produced by reacting the active terminal of the (co) polymer with a low molecular compound having two or more tertiary amino groups and two or more alkoxysilyl groups in the molecule. Since it has a specific modifying group in the molecule, the modified conjugated diene rubber composition of the present invention can exhibit the excellent effects described above.
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 etc. are mentioned, It uses 1 type or in combination of 2 or more types. Preferred compounds include 1,3-butadiene and isoprene.

Examples of the aromatic vinyl compound include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, diphenylethylene, and the like, and one or a combination of two or more types is used. A preferred compound is styrene.
The conjugated diene (co) polymer may be a random copolymer or a block copolymer. Examples of the random copolymer include a butadiene-isoprene random copolymer, a butadiene-styrene random copolymer, an isoprene-styrene random copolymer, and a butadiene-isoprene-styrene random copolymer. The composition distribution of each monomer in the copolymer chain includes a completely random copolymer having a statistically random composition, or a tapered random copolymer having a tapered composition distribution. The bonding mode of the conjugated diene, that is, the composition such as 1,4-bond and 1,2-bond may be uniform or distributed.

  Examples of the block copolymer include a 2-type block copolymer comprising 2 blocks, a 3-type block copolymer comprising 3 blocks, and a 4-type block copolymer comprising 4 blocks. For example, a block composed of an aromatic vinyl compound such as styrene is represented by S, and a block composed of a conjugated diene compound such as butadiene or isoprene and / or a block composed of a copolymer of an aromatic vinyl compound and a conjugated diene compound is represented by B. And an S—B2 type block copolymer, an S—B—S3 type block copolymer, a S—B—S—B4 type block copolymer, and the like. In the above equation, the boundaries of each block need not be clearly distinguished. When the block B is a copolymer of an aromatic vinyl compound and a conjugated diene compound, the aromatic vinyl compound in the block B may be distributed uniformly or in a tapered shape. In the block B, a plurality of portions where the aromatic vinyl compound is uniformly distributed and / or a plurality of portions where the aromatic vinyl compound is distributed in a tapered shape may coexist. In the block B, a plurality of segments having different aromatic vinyl compound contents may coexist. When a plurality of blocks S and blocks B are present in the copolymer, their structures such as molecular weight and composition may be the same or different.

As an example of the block copolymer, more generally, for example, a structure represented by the following general formula can be given.
(SB) n, S- (BS) n, B- (SB) n, (SB) m-X
[(SB) n] m-X, [(BS) n-B] m-X, [(SB) n-S] m-X
(N is an integer of 1 or more, preferably an integer of 1 to 5. m is an integer of 2 or more, preferably an integer of 2 to 11. X is the residue of the coupling agent or the remainder of the polyfunctional initiator. And the structure of the polymer chain bonded to X may be the same or different.)
In the present invention, the modified conjugated diene copolymer may be an arbitrary mixture having the structure represented by the above general formula.

  The modified conjugated diene-based (co) polymer of the present invention may be a hydrogenated conjugated diene-based (co) polymer obtained by converting all or part of the double bonds of the conjugated diene-based polymer into saturated hydrocarbons. . Such modified conjugated diene (co) polymers in which all or part of the double bonds are converted to saturated hydrocarbons have improved heat resistance and weather resistance, so that the product deteriorates when processed at high temperatures. In addition, the mobility of molecules can be changed, or the compatibility with other polymer compounds can be improved. As a result, such hydrogenated modified conjugated diene-based (co) polymers are preferable because they exhibit excellent performance in various applications such as automotive applications. More specifically, in the present invention, the hydrogenation rate (ie, hydrogenation rate) of the unsaturated double bond based on the conjugated diene compound can be arbitrarily selected according to the purpose, and is not particularly limited. When obtaining a polymer having good heat aging resistance and weather resistance, the hydrogenation rate of the unsaturated double bond based on the conjugated diene compound in the (co) polymer is preferably more than 70%. It is recommended that 75% or more, more preferably 85% or more, particularly preferably 90% or more is hydrogenated. In order to improve the thermal stability, molecular mobility or compatibility with the resin, the hydrogenation rate in the (co) polymer is preferably 3% to 70%, more preferably 5% to 65%, especially Preferably, it is 10% to 60%. The hydrogenation rate of the aromatic double bond based on the aromatic vinyl compound in the copolymer of the conjugated diene compound and the aromatic vinyl compound is not particularly limited, but the hydrogenation rate is preferably 50% or less. More preferably, it is 30% or less, and further preferably 20% or less. The hydrogenation rate can be measured by a nuclear magnetic resonance apparatus (NMR).

  As a hydrogenation method, a known method can be used. A particularly suitable hydrogenation method is a method in which gaseous hydrogen is blown into the polymer solution in the presence of a catalyst. As the catalyst, a heterogeneous catalyst, a catalyst in which a noble metal is supported on a porous inorganic substance, a homogeneous catalyst, a catalyst in which a salt such as nickel or cobalt is solubilized and reacted with organoaluminum, etc., a metallocene such as titanocene And the like. Of these, a titanocene catalyst capable of selecting mild hydrogenation conditions is particularly preferable. Also, hydrogenation of the aromatic group is possible by using a noble metal supported catalyst.

  For example, (1) a supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like (2) Ni, Co, Fe, Cr, or the like So-called Ziegler type hydrogenation catalyst using transition metal salt such as organic acid salt or acetylacetone salt and reducing agent such as organoaluminum, (3) so-called organometallic complex such as organometallic compound such as Ti, Ru, Rh, Zr Etc. Specific examples include Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-337970, Japanese Patent Publication No. 1-53851 and Japanese Patent Publication No. 2-5. The hydrogenation catalyst described in Japanese Patent Application Laid-Open No. 9041 and Japanese Patent Application Laid-Open No. 8-109219 can be used. A preferred hydrogenation catalyst is a reaction mixture of a titanocene compound and a reducing organometallic compound.

In this embodiment, the conjugated diene (co) polymer is preferably obtained by growing by the anionic polymerization reaction using the above-described polyfunctional anionic polymerization initiator as a polymerization initiator. In particular, the conjugated diene (co) polymer is more preferably a (co) polymer having an active end obtained by a growth reaction by living anionic polymerization. Thereby, a modified conjugated diene polymer having a high modification rate can be obtained. Although it does not specifically limit as a polymerization mode, It can carry out by polymerization modes, such as a batch type and a continuous type. In continuous mode, one or more connected reactors can be used. As the reactor, a tank type with a stirrer, a tube type or the like is used.
If the conjugated diene compound contains allenes, acetylenes or the like as impurities, there is a risk of inhibiting the modification reaction described later. Therefore, the total content concentration (mass) of these impurities is preferably 200 ppm or less, more preferably 100 ppm or less, and even more preferably 50 ppm or less. Examples of allenes include propadiene and 1,2-butadiene. Examples of acetylenes include ethyl acetylene and vinyl acetylene.

The polymerization reaction of the conjugated diene (co) polymer is preferably performed in a solvent. Examples of the solvent include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. 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; Examples thereof include hydrocarbons composed of a mixture thereof. Treatment of allenes and acetylenes, which are impurities, with an organometallic compound before being subjected to a polymerization reaction tends to yield a polymer having a high concentration of active terminals, and a high modification rate is achieved. It is preferable because of its tendency.
In the polymerization reaction of a conjugated diene (co) polymer, as a vinylating agent for controlling the microstructure of the conjugated diene part, or as a polymerization rate, for the purpose of randomly copolymerizing an aromatic vinyl compound with a conjugated diene compound A small amount of a polar compound may be added for the purpose of improving the above.

  Examples of polar compounds 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; tetramethylethylenediamine And tertiary amine compounds such as dipiperidinoethane, trimethylamine, triethylamine, pyridine and quinuclidine; alkali metal alkoxide compounds such as potassium tert-amylate, potassium tert-butylate, sodium tert-butylate and sodium amylate; A phosphine compound such as triphenylphosphine can be used. These polar compounds may be used alone or in combination of two or more.

The usage-amount of a polar compound is not specifically limited, It selects according to the objective and the grade of an effect. Usually, 0.01-100 mol is preferable with respect to 1 mol of polymerization initiators. An appropriate amount of such a polar compound (vinylating agent) can be used as a regulator of the microstructure of the polymer conjugated diene moiety depending on the desired vinyl bond amount. Many polar compounds simultaneously have an effective randomizing effect in the copolymerization of a conjugated diene compound and an aromatic vinyl compound, and can be used as an adjustment of the distribution of the aromatic vinyl compound and an adjuster of the styrene block amount. As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, a part of 1,3-butadiene is intermittently produced during the copolymerization as described in JP-A-59-140221. You may use the method of adding.
The polymerization temperature is not particularly limited as long as the living anion polymerization proceeds. From the viewpoint of productivity, the polymerization temperature is preferably 0 ° C. or more, and a sufficient reaction amount of the modifier with respect to the active terminal after the polymerization is ensured. From the viewpoint of achieving this, it is preferably 120 ° C. or lower.

The amount of bonded aromatic vinyl in the conjugated diene copolymer of the present embodiment is not particularly limited, but is preferably 5 to 70% by mass, and more preferably 10 to 50% by mass. When the amount of bonded aromatic vinyl is within the above range, a vulcanizate having a further excellent balance between low hysteresis loss and wet skid resistance and satisfying wear resistance and fracture strength can be obtained. Here, the amount of bonded aromatic vinyl can be measured by ultraviolet absorption of a phenyl group, and the amount of bonded conjugated diene can also be obtained from this. Specifically, it can measure by the method according to the Example mentioned later.
In addition, the conjugated diene-aromatic vinyl copolymer of the present embodiment preferably has few or no blocks in which 30 or more aromatic vinyl units are linked. Specifically, when the copolymer is a butadiene-styrene copolymer, the method described in Kolthoff (method described in IM KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946)). In a known method for decomposing a polymer and analyzing the amount of polystyrene insoluble in methanol, a block in which 30 or more aromatic vinyl units are chained is preferably 5% by mass or less, more preferably based on the amount of polymer. 3% by mass or less.

Moreover, the amount of vinyl bonds in the conjugated diene bond unit is not particularly limited, but is preferably 10 to 75 mol%, and more preferably 25 to 65 mol%. When the vinyl bond amount is in the above range, a vulcanizate having a further excellent balance between low hysteresis loss and wet skid resistance and satisfying wear resistance and fracture strength can be obtained. Here, when the modified conjugated diene-based polymer is a copolymer of butadiene and styrene, it is determined by the method of Hampton (RR Hampton, Analytical Chemistry, 21, 923 (1949)). A vinyl bond amount (1,2-bond amount) can be determined.
When the microstructure (the amount of each bond in the modified conjugated diene copolymer) is in the above range, and the glass transition temperature of the copolymer is in the range of −45 to −15 ° C., low hysteresis loss and A better vulcanizate can be obtained due to the balance of wet skid resistance. Regarding the glass transition temperature, in accordance with ISO 22768: 2006, a DSC curve is recorded while raising the temperature in a predetermined temperature range, and the peak top (Inflection point) of the DSC differential curve is defined as the glass transition temperature.

In the modified conjugated diene copolymer and modified conjugated diene polymer in the present embodiment, the polymerization active terminal is modified with a predetermined modifier.
Specifically, after obtaining a conjugated diene copolymer having an active end or a conjugated diene polymer by the above-described method, two or more tertiary amino groups in the molecule and an alkoxysilyl group are added to the active end. By reacting a compound having 2 or more, the modified conjugated diene-based (co) polymer in the present embodiment can be obtained.
As a compound having two or more tertiary amino groups and one or more alkoxysilyl groups in the molecule used for the modification reaction, the following formula (1)

(In the formula (1), R ¹ and R ² are each independently a hydrocarbon group having 1 to 12 carbon atoms, an unsaturated bond may be present, and each may be the same or different. R ³ and R ⁴ may be a hydrocarbon group having 1 to 20 carbon atoms and an unsaturated bond may be present, and R ⁵ , R ⁶ and R ⁷ include Si, O, or N; It is a C1-C20 hydrocarbon group that may be substituted with an organic group having no active hydrogen, and may have an unsaturated bond, and may be the same or different. i is an integer of 1 to 3.

(In the formula ^{(2), R 1, R} 2 are each independently an alkyl group having 1 to 20 carbon atoms, or an aryl group, ^{R 3} is an alkylene group having 1 to 20 carbon ^{atoms, R} 4, R ⁵ is a hydrocarbon group having 1 to 6 carbon atoms and has a ring structure of 5 or more members with two adjacent N atoms, and R ⁶ is a hydrocarbon group having 1 to 20 carbon atoms, a hetero group having no active hydrogen. (It is a C1-C20 hydrocarbon group substituted by an atom, or a 3 organic substituted silyl group, and m is an integer of 2 or 3.)
In the above formula (2), R ⁴ and R ⁵ may be the same or different.

(In the formula ^(3), R 1 ^{to R} 6, m the definition, the formulas (1) and are the same, ^{R 7} is replaced with a heteroatom having no hydrocarbon group having 1 to 20 carbon atoms, an active hydrogen Or a hydrocarbon group having 1 to 20 carbon atoms, or a triorgano-substituted silyl group.
It is represented by

  Examples of the compound represented by the general formula (1) include N- [2- (trimethoxysilanyl) -ethyl] -N, N ′, N′-trimethylethane-1,2-diamine, N- [2- (Dimethoxymethylsilanyl) -ethyl] -N-ethyl-N ′, N′-dimethylethane-1,2-diamine, N- [3- (trimethoxysilanyl) -propyl] -N, N ', N'-trimethylpropane-1,3-diamine, N- [3- (dimethoxymethylsilanyl) -propyl] -N-ethyl-N', N'-dimethylpropane-1,3-diamine, N- [3- (Triethoxysilanyl) -propyl] -N, N ′, N′-triethyl-2-methylpropane-1,3-diamine, N- [3- (dimethoxymethylsilanyl) -propyl] -2 , N, N ′, N′-tetrame Tylpropane-1,3-diamine, N- (2-dimethylaminoethyl) -N ′-[2- (trimethoxysilanyl) -ethyl] -N, N′-dimethylethane-1,2-diamine, N— [2- (Diethoxypropylsilanyl) -ethyl] -N ′-(3-ethoxypropyl) -N, N′-dimethylethane-1,2-diamine, N- [2- (trimethoxysilanyl)- Ethyl] -N′-methoxymethyl-N, N′-dimethylethane-1,2-diamine, N- [2- (trimethoxysilanyl) -ethyl] -N, N′-dimethyl-N ′-(2 -Trimethylsilanylethyl) -ethane-1,2-diamine, N- [2- (triethoxysilanyl) -ethyl] -N, N'-diethyl-N '-(2-dibutylmethoxysilanylethyl)- Ethane-1,2-diamine And the like. A preferred compound is N- [2- (trimethoxysilanyl) -ethyl] -N, N ′, N′-trimethylethane-1,2-diamine. A modified conjugated diene polymer modified with this compound is particularly excellent in the balance of wet skid characteristics, low hysteresis loss, wear resistance, and fracture strength when vulcanized.

  Examples of the compound represented by the formula (2) include 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3- (diethoxyethylsilyl) propyl] -4-methyl. Piperazine, 1- [3- (trimethoxysilyl) propyl] -3-methylimidazolidine, 1- [3- (diethoxyethylsilyl) propyl] -3-ethylimidazolidine, 1- [3- (triethoxysilyl) ) 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-tetrahydro Ropyrimidine, 1- (2-ethoxyethyl) -3- [3- (trimethoxysilyl) propyl] imidazolidine, (2- {3- [3- (trimethoxysilyl) propyl] tetrahydropyrimidin-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) pro L] -3- (trimethylsilyl) hexahydropyrimidine, 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) hexahydropyrimidine, 1- [4- (triethoxysilyl) butyl] -4- ( And trimethylsilyl) piperazine.

  Among these, 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3- (trimethoxysilyl) propyl] -3-methylimidazolidine, 1- [3- (triethoxysilyl) Propyl] -3-methylhexahydropyrimidine, 1- [3- (triethoxysilyl) propyl] -4- (trimethylsilyl) piperazine, 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) imidazolidine 1- [3- (triethoxysilyl) propyl] -3- (trimethylsilyl) hexahydropyrimidine is preferably used, and 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine, 1- [3- (Triethoxysilyl) propyl] -4- (trimethylsilyl) piperazine is more preferred.

  Examples of the compound represented by the above formula (3) include 2- [3- (trimethoxysilyl) propyl] -1,3-dimethylimidazolidine, 2- (diethoxyethylsilyl) -1,3-diethyl. Imidazolidine, 2- (triethoxysilyl) -1,4-diethylpiperazine, 2- (dimethoxymethylsilyl) -1,4-dimethylpiperazine, 5- (triethoxysilyl) -1,3-dipropylhexahydropyrimidine , 5- (diethoxyethylsilyl) -1,3-diethylhexahydropyrimidine, {2- [3- (2-dimethylaminoethyl) -2- (ethyldimethoxysilyl) -imidazolidin-1-yl] -ethyl } -Dimethylamine, 5- (trimethoxysilyl) -1,3-bis- (2-methoxyethyl) -hexahydropyrimidine, 5- Ethyldimethoxysilyl) -1,3-bis- (2-trimethylsilylethyl) -hexahydropyrimidine) -1,3-dimethylimidazolidine, 2- (3-diethoxyethylsilyl-propyl) -1,3-diethyl Imidazolidine, 2- (3-triethoxysilyl-propyl) -1,4-diethylpiperazine, 2- (3-dimethoxymethylsilyl-propyl) -1,4-dimethylpiperazine, 5- (3-triethoxysilyl- Propyl) -1,3-dipropylhexahydropyrimidine, 5- (3-diethoxyethylsilyl-propyl) -1,3-diethylhexahydropyrimidine, {2- [3- (2-dimethylaminoethyl) -2 -(3-Ethyldimethoxysilyl-propyl) -imidazolidin-1-yl] -ethyl} -dimethylamine 5- (3-trimethoxysilyl-propyl) -1,3-bis- (2-methoxyethyl) -hexahydropyrimidine, 5- (3-ethyldimethoxysilyl-propyl) -1,3-bis- (2- Trimethylsilylethyl) -hexahydropyrimidine, 2- [3- (trimethoxysilyl) propyl] -1,3-bis (trimethylsilyl) imidazolidine, 2- (diethoxyethylsilyl) -1,3-bis (triethylsilyl) Imidazolidine, 2- (triethoxysilyl) -1,4-bis (trimethylsilyl) piperazine, 2- (dimethoxymethylsilyl) -1,4-bis (trimethylsilyl) piperazine, 5- (triethoxysilyl) -1,3 -Bis (tripropylsilyl) hexahydropyrimidine and the like.

Among these, 2- [3- (trimethoxysilyl) propyl] -1,3-dimethylimidazolidine and 2- [3- (trimethoxysilyl) propyl] -1,3- (bistrimethylsilyl) imidazolidine are preferable. .
These modifiers may be used alone or in combination of two or more.
The reaction temperature, reaction time, and the like when the above-described modifier is reacted with the polymerization active terminal are not particularly limited, but are preferably reacted at 0 to 120 ° C. for 30 seconds or longer.
In the above-described modifier, the total number of moles of alkoxy groups bonded to silyl groups in the compound is 0.8 to 3 times the number of moles of alkali metal compound and / or alkaline earth metal compound added as a polymerization initiator. The range is preferably 1 to 2.5 times, and more preferably 1 to 2 times. The resulting modified conjugated diene polymer is preferably 0.8 times or more in order to obtain a sufficient modification rate, and a branched polymer component is obtained by coupling polymer ends to improve processability. Is preferably 3 times or less from the viewpoint of the cost of the modifier.

  From the viewpoint of making the effect of the present embodiment more excellent, the modified conjugated diene-based (co) polymer is preferably contained in an amount of 5% by mass or more, more preferably 20% by mass or more, and further preferably 50% by mass or more. It is preferable to produce a modified conjugated diene-based (co) polymer so as to be a polymer. As a method for quantifying a polymer having a functional group-containing modified component, it can be measured by chromatography capable of separating the functional group-containing modified component and the non-modified component. As a method using this chromatography, there is a method in which a GPC column using a polar substance such as silica adsorbing a functional group component as a filler is used and the internal standard of the non-adsorbed component is used for comparison.

In the method for producing the modified conjugated diene-based (co) polymer of the present embodiment, a deactivation agent, a neutralizing agent, etc. may be added to the copolymer solution as necessary after the modification reaction. Good. Examples of the quenching agent include water; alcohols such as methanol, ethanol, and isopropanol. Examples of the neutralizing agent include carboxylic acids such as stearic acid, oleic acid, and versatic acid; aqueous solutions of inorganic acids, carbon dioxide gas, and the like.
In addition, the modified conjugated diene-based (co) polymer of this embodiment may be added with a rubber stabilizer from the viewpoint of preventing gel formation in the finishing step after polymerization and improving stability during processing. Is preferred. The stabilizer for rubber is not particularly limited, and known ones can be used, but 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3- (4′-hydroxy) -3 ′, 5′-di-tert-butylphenol) propinate, 2-methyl-4,6-bis [(octylthio) methyl] phenol and the like are preferable.

  Moreover, in order to improve the workability of the modified conjugated diene-based (co) polymer of the present embodiment, an extending oil can be added to the modified conjugated diene-based copolymer as necessary. The method of adding the extending oil to the modified conjugated diene polymer is not particularly limited, but a method of adding the extending oil to the polymer solution and mixing to remove the solvent from the oil-extended copolymer solution is preferable. . Examples of the extending oil include aroma oil, naphthenic oil, paraffin oil, and the like. Among these, from the viewpoint of environmental safety, oil bleed prevention and wet grip characteristics, an aromatic substitute oil having a polycyclic aromatic (PCA) component of 3% by mass or less by the IP346 method is preferable. Examples of the aroma substitute oil include RAE and the like in addition to TDAE and MES shown in Kautschuk Gummi Kunststoff 52 (12) 799 (1999). Although the addition amount of extending oil is not specifically limited, Usually, it is 10-60 mass parts with respect to 100 mass parts of modified conjugated diene polymers, and 20-37.5 mass parts is preferable.

As a method for obtaining the modified conjugated diene polymer of the present embodiment from the polymer solution, a known method can be used. 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. The method, the method of devolatilizing directly with a drum dryer etc. are mentioned.
The blending ratio (mass ratio) of the modified conjugated diene rubber composition of the present embodiment is preferably 10/90 to 90/10 as modified conjugated diene copolymer (A) / modified conjugated diene polymer (B). 30/70 to 90/10 are more preferable, and 50/50 to 80/20 are even more preferable. When the blending ratio of the modified conjugated diene copolymer (A) / modified conjugated diene polymer (B) is within the above range, the balance between low hysteresis loss and wet skid resistance is further improved, and wear resistance and fracture strength are improved. Furthermore, a vulcanizate that is more satisfactory can be obtained.

  The modified conjugated diene rubber composition of this embodiment is suitably used as a vulcanizate. The vulcanized product may be, for example, the modified conjugated diene rubber composition of the present embodiment, if necessary, an inorganic filler such as silica inorganic filler or carbon black, or the modified conjugated diene rubber composition of the present embodiment. It is mixed with a rubbery polymer other than the above, a silane coupling agent, a rubber softening agent, a vulcanizing agent, a vulcanization accelerator / auxiliary, etc. to obtain a modified conjugated diene polymer composition, and then heated to be added. It can be obtained by sulfuration. Among these, a modified conjugated diene polymer composition containing a rubber component containing the modified conjugated diene rubber composition of the present embodiment and a silica inorganic filler is preferable. Dispersing the silica-based inorganic filler in the modified conjugated diene rubber composition of the present embodiment, when used as a vulcanized product, has an excellent balance between low hysteresis loss and wet skid resistance, and practically It has sufficient wear resistance and breaking strength, and can provide excellent workability. The modified conjugated diene polymer composition of the present embodiment also includes a silica-based inorganic filler as a reinforcing filler even when used for vulcanized rubber applications such as tires, automobile parts such as vibration-proof rubber, and shoes. It is preferable.

  In the modified conjugated diene rubber composition, a rubbery polymer other than the modified conjugated diene (co) polymer of this embodiment can be used in combination with the modified conjugated diene (co) polymer of this embodiment. Examples of such a rubbery polymer include a conjugated diene polymer or a hydrogenated product thereof, a random copolymer of a conjugated diene compound and a vinyl aromatic compound, or a hydrogenated product thereof, a conjugated diene compound and a vinyl. Examples thereof include a block copolymer with an aromatic compound or a hydrogenated product thereof, a non-diene polymer, and natural rubber. Specifically, butadiene rubber or hydrogenated product thereof, isoprene rubber or hydrogenated product thereof, styrene-butadiene rubber or hydrogenated product thereof, styrene-butadiene block copolymer or hydrogenated product thereof, styrene-isoprene block copolymerized Examples thereof include styrene-based elastomers such as coalescence or hydrogenated products thereof, acrylonitrile-butadiene rubber, or hydrogenated products thereof.

Non-diene polymers include olefin elastomers such as ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-butene-diene rubber, ethylene-butene rubber, ethylene-hexene rubber, ethylene-octene rubber, butyl rubber, brominated butyl rubber, acrylic Examples thereof include rubber, fluororubber, silicone rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, α, β-unsaturated nitrile-acrylic ester-conjugated diene copolymer rubber, urethane rubber, polysulfide rubber and the like.
The various rubber-like polymers described above may be modified rubbers to which functional groups having polarity such as hydroxyl groups and amino groups are added. The weight average molecular weight is preferably 2,000 to 2,000,000, more preferably 5,000 to 1,500,000, from the viewpoint of the balance between performance and processing characteristics. Also, so-called liquid rubber having a low molecular weight can be used. These rubbery polymers may be used alone or in combination of two or more.

The silica-based inorganic filler is not particularly limited, but may be a known, SiO _2, or _Si 3 solid particles preferably contains Al as a constituent unit, SiO _2, or _Si 3 Al constituent units It is more preferable to use as a main component. 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. In addition, a silica-based inorganic filler having a hydrophobic surface or a mixture of a silica-based inorganic filler and a non-silica inorganic filler can also be used. Among these, silica and glass fiber are preferable from the viewpoint of reinforcing properties, and silica is more preferable. Examples of silica include dry silica, wet silica, and synthetic silicate silica. Among these, wet silica is preferable from the viewpoint of an excellent balance between the effect of improving fracture characteristics and wet skid resistance.

In the modified conjugated diene rubber composition, the nitrogen adsorption specific surface area required by the BET adsorption method of silica-based inorganic filler is 100 to 300 m ² / g from the viewpoint of obtaining practically good wear resistance and fracture characteristics. It is preferable that it is 170-250 m < ² > / g. In addition, if necessary, the specific surface area is relatively small (for example, a silica-based inorganic filler having a specific surface area of 200 m ² / g or less), and the specific surface area is relatively large (for example, a silica-based inorganic having a specific surface area of 200 m ² / g or more). And a filler) can be used in combination. Thereby, it is possible to highly balance good wear resistance and fracture characteristics with low hysteresis loss.

As described above, the compounding amount of the silica-based inorganic filler in the modified conjugated diene rubber composition is 0.5 to 100 parts by mass with respect to 100 parts by mass of the rubber component containing the modified conjugated diene (co) polymer of the present embodiment. It is preferably 300 parts by mass, more preferably 5 to 200 parts by mass, and even more preferably 20 to 100 parts by mass. The compounding amount of the silica-based inorganic filler is preferably 0.5 parts by mass or more from the viewpoint of manifesting the effect of adding the inorganic filler. On the other hand, the inorganic filler is sufficiently dispersed to process the composition. And from the viewpoint of making the mechanical strength practically sufficient, it is preferably 300 parts by mass or less.
The vulcanized product of the modified conjugated diene rubber composition has a storage elastic modulus difference (ΔG ′) of 0.8 MPa or less measured at a frequency of 10 ° C. at 50 ° C. and strains of 0.1% and 10%, such as silica. Good dispersibility.

The modified conjugated diene rubber composition may contain carbon black. The carbon black is not particularly limited, and for example, carbon blacks of each class such as SRF, FEF, HAF, ISAF, and SAF can be used. Among these, carbon black having a nitrogen adsorption specific surface area of 50 m ² / g or more and a DBP oil absorption of 80 mL / 100 g is preferable.
The blending amount of carbon black is preferably 0.5 to 100 parts by weight, more preferably 3 to 100 parts by weight, and more preferably 5 to 50 parts by weight with respect to 100 parts by weight of the rubber component containing the modified conjugated diene polymer of the present embodiment. Part is more preferred. The blending amount of the carbon black is preferably 0.5 parts by mass or more from the viewpoint of expressing performances required for tires such as dry grip performance and conductivity, and 100 parts by mass from the viewpoint of dispersibility. The following is preferable.
The modified conjugated diene rubber composition may contain a metal oxide or a metal hydroxide in addition to the silica inorganic filler and carbon black. The metal oxide refers to solid particles whose main component is a chemical unit MxOy (M represents a metal atom, and x and y each represent an integer of 1 to 6). For example, alumina, oxidation Titanium, magnesium oxide, zinc oxide, or the like can be used. A mixture of a metal oxide and an inorganic filler other than the metal oxide can also be used. The metal hydroxide is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

The modified conjugated diene rubber composition may contain a silane coupling agent. 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. In general, a compound having a sulfur bond portion, an alkoxysilyl group, and a silanol group portion in one molecule is used. Specifically, bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (triethoxysilyl) -ethyl ] -Tetrasulfide etc. are mentioned.
0.1-30 mass parts is preferable with respect to 100 mass parts of silica type inorganic fillers mentioned above, as for the compounding quantity of a silane coupling agent, 0.5-20 mass parts is more preferable, and 1-15 mass parts is. Further preferred. When the blending amount of the silane coupling agent is within the above range, the addition effect of the silane coupling agent can be made more remarkable.

In order to improve processability, the modified conjugated diene rubber composition may contain a rubber softener. As the rubber softener, mineral oil or a liquid or low molecular weight synthetic softener is suitable. The mineral oil rubber softener called process oil or extender oil used for softening, increasing volume and improving processability of rubber is a mixture of aromatic ring, naphthene ring and paraffin chain. 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. As the rubber softener used together with the modified conjugated diene-aromatic vinyl copolymer of the present embodiment, those having an appropriate aromatic content are preferred because they tend to be familiar with the copolymer.
The blending amount of the rubber softener is preferably 0 to 100 parts by weight, more preferably 10 to 90 parts by weight, with respect to 100 parts by weight of the rubber component containing the modified conjugated diene rubber composition of the present embodiment. -90 mass parts is further more preferable. If the blending amount of the rubber softener exceeds 100 parts by mass with respect to 100 parts by mass of the rubber component, bleeding out tends to occur, and the composition surface may become sticky.

  The modified conjugated diene-based (co) polymer of this embodiment and other rubber-like polymers, silica-based inorganic fillers, carbon black and other fillers, silane coupling agents, rubber softeners, and other additives are mixed. There are no particular restrictions on the method used. 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. Also, any of a method of kneading the modified conjugated diene-based (co) polymer and various compounding agents at a time and a method of mixing in multiple times can be applied.

The modified conjugated diene rubber composition 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. The amount of the vulcanizing agent used is usually 0.01 to 20 parts by mass, preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer of the present embodiment. . A conventionally known method can be applied as the vulcanization method, and the vulcanization temperature is usually 120 to 200 ° C, preferably 140 to 180 ° C.
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. Further, as the vulcanization aid, zinc white, stearic acid or the like can be used. The amount of the vulcanization accelerator used is usually 0.01 to 20 parts by mass, and 0.1 to 15 parts by mass with respect to 100 parts by mass of the rubber component containing the modified conjugated diene polymer of the present embodiment. preferable.

  In the modified conjugated diene rubber composition, other softening agents and fillers other than those mentioned above, as well as heat stabilizers, antistatic agents, weathering stabilizers, and anti-aging, are within the range not impairing the purpose of the present embodiment. Various additives such as a colorant, a colorant, and a lubricant may be used. As other softeners, known softeners can be used. Specific examples of other fillers include calcium carbonate, magnesium carbonate, aluminum sulfate, and barium sulfate. Known materials can be used as the above heat stabilizer, antistatic agent, weathering stabilizer, anti-aging agent, colorant, and lubricant.

The present embodiment will be described in more detail with reference to the following examples, but the present embodiment is not limited to the following examples. The sample was analyzed by the method shown below.
(1) Amount of bound styrene A sample was used as a chloroform solution, and the amount of bound styrene (mass%) was measured by absorption at UV254 nm by the phenyl group of styrene (manufactured by Shimadzu Corporation: UV-2450).
(2) Microstructure of butadiene moiety (1,2-vinyl bond content)
The sample is a carbon disulfide solution, a solution cell is used, the infrared spectrum is measured in the range of 600 to 1000 cm −1, and the microstructure of the butadiene part is determined by the absorbance at a predetermined wave number according to the calculation formula of the Hampton method or Morello method (Manufactured by JASCO Corporation: FT-IR230).

(3) Mooney viscosity According to JIS K 6300, preheating was performed at 100 ° C. for 1 minute, and the viscosity after 4 minutes was measured.
(4) Weight average molecular weight and molecular weight distribution Chromatogram was measured using gel permeation chromatography (GPC) using three connected columns with polystyrene gel as a filler, and standard polystyrene was used. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were obtained from the calibration curve, and the molecular weight distribution index (Mw / Mn) was calculated from the ratio of the weight average molecular weight to the number average molecular weight.
Tetrahydrofuran (THF) was used as the eluent.
As the column, guard column: Tosoh TSKguardcolumn HHR-H, column: Tosoh TSKgel G6000HHR, TSKgel G5000HHR, TSKgel G4000HHR were used.
The molecular weight was measured using an RI detector of HLC8020 manufactured by Tosoh under conditions of an oven temperature of 40 ° C. and a THF flow rate of 1.0 mL / min. A sample of 10 mg was dissolved in 20 mL of THF, and 200 μL of this solution was injected into the apparatus for measurement.

(5) 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), GPC of the polystyrene gel column and silica column (guard column: DIOL 4.6 × 12.5 mm 5 micron, column: Zorbax PSM-1000S, PSM-300S, PSM-60S, oven temperature 40 ° C., THF flow rate 0.5 ml. / Min) GPC (Tosoh CCP8020 series build-up GPC system: AS-8020, SD-8022, CCPS, CO-8020, RI-8021) both chromatograms were measured using an RI detector, Measure the amount adsorbed on the silica column from the difference between the two and denature The rate was determined.
As a sample, 10 mg was dissolved in 20 mL of THF together with 5 mg of standard polystyrene, and 200 μL was injected for measurement.
As a specific procedure, the peak area of the chromatogram using the polystyrene column is set to 100, the peak area of the standard polystyrene is P2, the peak area of the standard polystyrene is P2, and the peak area of the chromatogram using the silica column is P1. Assuming 100 as a whole, the peak area of the sample was P3, the peak area of standard polystyrene was P4, and the modification rate (%) was calculated by the formula [1- (P2 × P3) / (P1 × P4)] × 100. .

(Conjugated diene (co) polymer)
The conjugated diene-based (co) polymer before modification is obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound or polymerizing a conjugated diene compound using the following polyfunctional anionic polymerization initiator. .
(Preparation of polyfunctional anionic polymerization initiators a to d)
After washing and drying an autoclave equipped with a stirring device and a jacket having an internal volume of 10 L and purging with nitrogen, 1,3-butadiene, cyclohexane, tetrahydrofuran and divinylbenzene subjected to a drying treatment according to the conditions shown in Table 1 below were used. Then, n-butyl lithium was added and reacted at 75 ° C. for 1 hour to prepare.
The polyfunctional anionic polymerization initiator prepared under the conditions shown in Table 1 below was soluble in cyclohexane and had no gel.
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, etc. and having a divinylbenzene concentration of 57% by weight is used. It was.
About the amount of divinylbenzene in the following Table 1, since the said commercially available divinylbenzene is a mixture, the pure amount of divinylbenzene converted excluding the content of impurities was expressed.

(Preparation of polyfunctional anionic polymerization initiator e)
In a three-way flask equipped with a magnetic stirrer, a cooling tube and a dropping funnel were set, and after nitrogen replacement, slightly pressurized nitrogen was circulated, and the inside of the system was sealed. Then, 99.0 mL (100 mmol) of a cyclohexane / n-hexane mixed solution of 0.01 mol / L of sec-butyllithium, 13.9 mL (100 mmol) of triethylamine, and 10 mL of cyclohexane were mixed and stirred at 20 ° C.
Further, 7.91 g (50 mmol) of m-diisopropenylbenzene purified by distillation under reduced pressure was added dropwise at room temperature over 3 hours, and stirring was continued for 15 hours to prepare.

[Production of Modified Copolymer SB1 (Component A)]
An autoclave with an internal volume of 10 liters and a temperature-controllable autoclave equipped with a stirrer and a jacket was used as a reactor, and 740 g of butadiene, 260 g of styrene, 4800 g of cyclohexane from which impurities were previously removed, -Oxolanyl) propane 0.85 g was charged into the reactor and the temperature in the reactor was maintained at 42 ° C.
The polyfunctional polymerization initiator a prepared as described above was supplied to the reactor so that the amount of lithium added was 10.5 mmol. 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 75 ° C.

After the completion of the polymerization reaction, 5.25 mmol of 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine was added to the reactor, and a denaturation reaction was performed for 5 minutes at a temperature of 74 ° C. After adding 2.1 g of an antioxidant (2,6-di-t-butyl-p-cresol: BHT) to this polymer solution, the solvent is removed by steam stripping and a drying process is performed by a dryer. Then, a styrene-butadiene copolymer (sample SB1) having a modifying component was obtained.
As a result of analyzing sample SB1, the amount of bound styrene was 26% by mass and the amount of bound butadiene was 74% by mass. The Mooney viscosity of Sample SB1 was 56.
The 1,2-bond content of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement result using an infrared spectrophotometer was 57%. Moreover, the modification | denaturation rate calculated | required from GPC using a silica type adsorption column was 89%. The analysis results of sample SB1 are shown in Table 2 below.

[Production of modified copolymers SB2 and SB3 (component A)]
The types of polyfunctional anionic polymerization initiators mentioned above, the addition amounts thereof, the addition amounts of 2,2-bis (2-oxolanyl) propane, and 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine As shown in Table 2 below, (Sample SB2) and (Sample SB3) were obtained as manufacturing methods in the same manner as described above.
Table 2 below shows the analysis results of the styrene-butadiene copolymers (sample SB2) and (sample SB3) having a modifying component.

[Production of Modified Copolymer SB4 (Component A)]
An autoclave with an internal volume of 10 liters and a temperature-controllable autoclave equipped with a stirrer and a jacket was used as a reactor, and 740 g of butadiene, 260 g of styrene, 4800 g of cyclohexane from which impurities were previously removed, -Oxolanyl) propane 1.01 g was charged into the reactor and the temperature in the reactor was maintained at 42 ° C.
After adding 6.3 mmol of the above-mentioned polyfunctional anionic polymerization initiator e and 4.8 mmol of normal butyl lithium as lithium addition amount, the mixture was supplied to the reactor.
At this time, the ratio of the polyvinyl aromatic compound added to the polymerization system and lithium was 0.284.
After the start of the polymerization reaction, the temperature inside the reactor started to rise due to the exotherm caused by the polymerization, and the final temperature inside the reactor reached 74 ° C. After the completion of the polymerization reaction, 6.93 mmol of 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine was added to the reactor, and a denaturation reaction was performed at 73 ° C. for 5 minutes.
After adding 2.1 g of an antioxidant (BHT) to the polymer solution, the solvent is removed by steam stripping, and a drying treatment is performed by a dryer to obtain a styrene-butadiene copolymer (sample SB4) having a modifying component. Obtained. The analysis results of sample SB4 are shown in Table 2 below.

[Production of Modified Copolymer SB5-8 (Component A)]
Using the polyfunctional anionic polymerization initiator b, a styrene-butadiene copolymer is obtained by the same production method as that of SB2, and then the modification is performed by changing the type of the modifier as shown in Table 2 below. A styrene-butadiene copolymer (samples SB5 to 8) was obtained. The analysis results of Sample 5 to Sample 8 are shown in Table 2 below.

[Production of Modified Copolymer SB9 (Component A)]
An autoclave with an internal volume of 10 liters and a temperature-controllable autoclave equipped with a stirrer and a jacket was used as a reactor, and 740 g of butadiene, 260 g of styrene, 4800 g of cyclohexane from which impurities were previously removed, -0.62 g of oxolanyl) propane was charged into the reactor and the reactor internal temperature was maintained at 42 ° C. As a polymerization initiator, a cyclohexane solution containing 7.5 mmol of n-butyllithium was supplied to the reactor. After the polymerization reaction started, the temperature in the reactor started to rise due to the exotherm due to polymerization, and the final temperature in the reactor reached 71 ° C. After completion of the polymerization reaction, 0.28 mmol of tetraglycidyl-1,3-bisaminomethylcyclohexane was added to the reactor, and the mixture was stirred at 70 ° C. for 2 minutes to carry out a modification reaction. Thereafter, 4.0 mmol of 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine was further added, and a denaturing reaction was carried out at 69 ° C. for 5 minutes.

After adding 2.1 g of an antioxidant (BHT) to this polymer solution, the solvent is removed by steam stripping, and a drying treatment is performed by a dryer, so that a styrene-butadiene copolymer having a modifying component (sample) SB9) was obtained. The tetraglycidyl-1,3-bisaminomethylcyclohexane is a modifier having four reaction sites with the polymer active terminal, and suppresses cold flow by increasing the molecular weight of a part of the polymer. Added for.
On the other hand, in (Samples SB1 to SB8), by using a polyfunctional initiator, a part of the polymer after modification has a high molecular weight and has a cold flow suppressing effect. Therefore, tetraglycidyl-1,3- There was no need for modification with bisaminomethylcyclohexane.
As a result of analyzing sample SB9, the amount of bound styrene was 26% by mass and the amount of bound butadiene was 74%. The Mooney viscosity of the polymer was 65.
The 1,2-bond amount of the microstructure of the butadiene portion determined by calculation according to the Hampton method from the measurement result using an infrared spectrophotometer is 56%, and was determined from GPC using a silica-based adsorption column. The modification rate was 82%.

[Production of Modified Polymer B1 (Component B)]
An autoclave having an internal volume of 10 liters and equipped with a stirrer and a jacket and capable of temperature control is used as a reactor. Held on. The polyfunctional polymerization initiator a prepared as described above was supplied to the reactor so that the amount of lithium added was 10.5 mmol. After the start of the reaction, the temperature inside the reactor started to rise due to the exotherm due to polymerization, and the final temperature in the reactor reached 79 ° C. After completion of the polymerization reaction, 5.25 mmol of 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine was added to the reactor, and a denaturation reaction was performed for 5 minutes at a temperature of 77 ° C. After adding 2.1 g of an antioxidant (2,6-di-t-butyl-p-cresol: BHT) to this polymer solution, the solvent is removed by steam stripping and a drying process is performed by a dryer. Then, a butadiene polymer (sample B1) having a modifying component was obtained.
As a result of analyzing Sample B1, the Mooney viscosity was 50. The 1,2-bond amount of the microstructure of the butadiene portion determined by calculation according to the Morero method from the measurement result using an infrared spectrophotometer was 13. Moreover, the modification | denaturation rate calculated | required from GPC using a silica type adsorption column was 93%. The analysis results of Sample B1 are shown in Table 2 below.

[Production of Modified Polymers B2 to B4 (Component B)]
The types of polyfunctional anionic polymerization initiators and their addition amounts, the types and addition amounts of modifiers are adjusted as shown in Table 2 below, and sample B2 is prepared by the same method (sample B1) as the production conditions described above. ~ B4 was obtained. Table 2 below shows the analysis results of the butadiene polymers having a modifying component (sample B2), (sample B3), and (sample B4).

[Production of Modified Polymer B5 (Component B)]
An autoclave having an internal volume of 10 liters and equipped with a stirrer and a jacket and capable of temperature control is used as a reactor. Retained. As a polymerization initiator, a cyclohexane solution containing 7.5 mmol of n-butyllithium was supplied to the reactor. After the polymerization reaction started, the temperature in the reactor started to rise due to the exotherm due to polymerization, and the final temperature in the reactor reached 71 ° C. After completion of the polymerization reaction, 0.28 mmol of tetraglycidyl-1,3-bisaminomethylcyclohexane was added to the reactor, and the mixture was stirred at 70 ° C. for 2 minutes to carry out a modification reaction. Thereafter, 4.0 mmol of 1- [3- (triethoxysilyl) propyl] -4-methylpiperazine was further added, and a denaturing reaction was carried out at 69 ° C. for 5 minutes.

After adding 2.1 g of an antioxidant (BHT) to this polymer solution, the solvent is removed by steam stripping, and drying treatment is performed by a dryer to give a butadiene copolymer having a modifying component (sample B5). Got. The tetraglycidyl-1,3-bisaminomethylcyclohexane is a modifier having four reaction sites with the polymer active terminal, and suppresses cold flow by increasing the molecular weight of a part of the polymer. Added for.
On the other hand, in (Samples B1 to B4), by using a polyfunctional initiator, a part of the polymer after modification has a high molecular weight and has a cold flow suppressing effect. Therefore, tetraglycidyl-1,3- There was no need for modification with bisaminomethylcyclohexane.
As a result of analyzing sample SB4, the Mooney viscosity of the polymer was 51. The 1,2-bond amount of the microstructure of the butadiene portion determined by calculation according to the Morero method from the measurement results using an infrared spectrophotometer is 13%, and was determined from GPC using a silica-based adsorption column. The modification rate was 93%.

[Examples 1-8, Comparative Examples 1-5]
Using the samples shown in Table 2 (samples SB1 to SB10 and samples B1 to B5) as raw rubber, rubber compositions containing the respective raw rubbers were obtained according to the formulation shown below.
Modified styrene-butadiene copolymer (samples SB1 to SB10) 80.0 parts by mass Modified butadiene polymer (samples B1 to B5) 20.0 parts by mass Silica (Ultrasil VN3 manufactured by Degussa) 75.0 parts by mass Carbon black (Tokai N339 manufactured by Carbon Co., Ltd.) 5.0 parts by mass silane coupling agent (Si69 manufactured by Degussa) 7.5 parts by mass S-RAE oil (JOMO process NC140 manufactured by Japan Energy) 37.5 parts by mass Zinc Hana 2.5 parts by mass Stearic acid 2.0 parts by weight antioxidant (N-isopropyl-N'-phenyl-p-phenylenediamine) 2.0 parts by weight sulfur 1.7 parts by weight vulcanization accelerator (N-cyclohexyl-2-benzothiazyl) Sulphinamide) 1.7 parts by mass Vulcanization accelerator (diphenylguanidine) 1.5 parts by mass Total 236.4 parts by mass

The rubber composition was kneaded by the following method.
Using a closed kneader equipped with a temperature control device (with an internal volume of 0.3 liters), as the first stage kneading, under the conditions of a filling rate of 65% and a rotor rotational speed of 50/57 rpm, raw rubber (modified styrene-butadiene) Copolymer, modified butadiene polymer), filler (silica, carbon black), organosilane coupling agent, process oil, zinc white, and stearic acid were kneaded.
At this time, the temperature of the closed mixer was controlled, and the rubber composition was obtained at a discharge temperature (compound) of 155 to 160 ° C.
Next, as the second stage kneading, the blend obtained above was cooled to room temperature, an anti-aging agent was added, and kneaded again to improve silica dispersion. Also in this case, the discharge temperature (formulation) was adjusted to 155 to 160 ° C. by controlling the temperature of the mixer.
Next, as the third stage of kneading, the blend obtained above was cooled to room temperature and then kneaded again to improve the dispersion of silica. Also in this case, the discharge temperature (formulation) was adjusted to 155 to 160 ° C. by controlling the temperature of the mixer.
After cooling, as a fourth stage of kneading, sulfur and a vulcanization accelerator were added and kneaded with an open roll set at 70 ° C. Then, it shape | molded and vulcanized with the vulcanization press for 20 minutes at 160 degreeC.
After vulcanization, the physical properties of the rubber composition were measured. The physical property measurement results are shown in Table 3 below.

[Comparative Example 6]
A vulcanizate was obtained in the same manner as in Example 1 except that natural rubber (NR) was used instead of the modified butadiene polymer. After vulcanization, the physical properties of the rubber composition were measured. The physical property measurement results are shown in Table 3 below.
The physical properties of the rubber composition were measured by the following methods.
<Bound rubber amount>
Formulation after completion of the second stage kneading step: About 0.2 gram was cut into a square of about 1 mm, put into a Harris basket (100 mesh wire mesh), and the weight was measured.
Then, after being immersed in toluene for 24 hours, a drying treatment was performed and the weight was measured.
The amount of rubber bound to the filler (modified conjugated diene polymer + natural rubber) was calculated from the amount of the undissolved component, and the ratio of the rubber bound to the filler to the amount of rubber in the first blend was determined.
<Formulation Mooney viscosity>
Using a Mooney viscometer, according to JIS K6300-1, after preheating at 130 ° C. for 1 minute, the rotor was rotated at 2 revolutions per minute, and the viscosity after 4 minutes was measured.
<Tensile strength>
It was measured by the tensile test method of JIS K6251.

<Viscoelastic parameters>
A viscoelasticity tester (ARES) manufactured by Rheometrics Scientific was used to measure viscoelastic parameters in torsional mode.
Tan δ measured at 0 ° C. with a frequency of 10 Hz and a strain of 1% was used as an index of wet grip performance. A larger value indicates better wet grip performance.
Further, tan δ measured at 50 ° C. with a frequency of 10 Hz and a strain of 3% was used as an index of fuel saving characteristics. A smaller value indicates better fuel economy performance.
Further, the difference in storage elastic modulus (G ′) between strains of 0.1% and 10% was used as an index of the Payne effect as ΔG ′. The smaller the value, the better the dispersibility of the filler such as silica.
<Abrasion resistance>
Using an Akron abrasion tester, the wear amount at a load of 6 pounds and 1000 revolutions was measured and indexed.
A larger index indicates better wear resistance.

  The composition obtained by combining the modified conjugated diene polymer of the present invention with an inorganic filler is excellent in the balance of physical properties such as wet skid characteristics, low hysteresis loss, wear resistance, and fracture strength, and processability. There is industrial applicability in fields such as interior / exterior products, anti-vibration rubber, belts, footwear, foams, various industrial parts, and tire applications.

Claims (6)

(A) Using a polyfunctional anionic polymerization initiator having a molecular weight distribution measured using gel permeation chromatography (GPC) in the range of 1.2 to 3.5, a conjugated diene compound, an aromatic vinyl compound, Modified conjugated diene system obtained by reacting a compound having one or more nitrogen atoms with a silyl group substituted with two or more alkoxy groups at the active end of the resulting polymer Polymerize conjugated diene compound using copolymer and (B) polyfunctional anionic polymerization initiator whose molecular weight distribution measured using gel permeation chromatography (GPC) is in the range of 1.2 to 3.5 Then, a modified conjugated die obtained by reacting a silyl group substituted with two or more alkoxy groups with a compound having one or more nitrogen atoms at the active terminal of the obtained polymer. A modified conjugated diene rubber composition comprising a polymer. (A) In a hydrocarbon solvent, using a polyfunctional anionic polymerization initiator prepared in a molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) in the range of 0.05 to 1.0, After copolymerizing a conjugated diene compound and an aromatic vinyl compound, the resulting polymer is reacted with a silyl group substituted with two or more alkoxy groups at the active end of the polymer and a compound having one or more nitrogen atoms. The modified conjugated diene copolymer obtained by the above and (B) In the hydrocarbon solvent, the molar ratio of polyvinyl aromatic compound to lithium (polyvinyl aromatic compound / lithium) is in the range of 0.05 to 1.0. After polymerizing a conjugated diene compound using the prepared polyfunctional anionic polymerization initiator, a silyl group substituted with two or more alkoxy groups at the active terminal of the obtained polymer and one or more nitrogen atoms A modified conjugated diene rubber composition comprising a modified conjugated diene polymer obtained by reacting a compound having a child. The compound having a silyl group substituted with two or more alkoxy groups and one or more nitrogen atoms is a compound represented by the following general formula (1), general formula (2) or general formula (3) The modified conjugated diene rubber composition according to claim 1 or 2.
(In the formula ^(1), a R 1, ^{R 2} are each independently a hydrocarbon group having 1 to 12 carbon ^atoms, R 3, ^{R 4} is a hydrocarbon group having 1 to 20 carbon atoms, R ⁵ , R ⁶ , R ⁷ may be a C 1-20 hydrocarbon group that contains Si, O, or N and may be substituted with an organic group having no active hydrogen. It is an integer of 3.)
(In the formula ^{(2), R 1, R} 2 are each independently an alkyl group having 1 to 20 carbon atoms, or an aryl group, ^{R 3} is an alkylene group having 1 to 20 carbon ^{atoms, R} 4, R ⁵ is a hydrocarbon group having 1 to 6 carbon atoms and has a ring structure of 5 or more members with two adjacent Ns, and R ⁶ has no hydrocarbon group having 1 to 20 carbon atoms and active hydrogen (It is a C1-C20 hydrocarbon group substituted by a hetero atom, or a 3 organic substituted silyl group, and m is an integer of 2 or 3.)
(In the formula ^(3), R 1 ^{to R} 6, m the definition, the formulas (1) and are the same, ^{R 7} is replaced with a heteroatom having no hydrocarbon group having 1 to 20 carbon atoms, an active hydrogen Or a hydrocarbon group having 1 to 20 carbon atoms, or a triorgano-substituted silyl group.   A modified conjugated diene rubber composition comprising 0.5 to 300 parts by mass of a silica-based inorganic filler with respect to 100 parts by mass of a rubber component comprising the modified conjugated diene rubber composition according to any one of claims 1 to 3.   At a frequency of 10 Hz, strain of 0.1% and 10% of a vulcanized product of a modified conjugated diene rubber composition containing 75 parts by mass of a silica-based inorganic filler with respect to 100 parts by mass of the modified conjugated diene rubber composition. A modified conjugated diene rubber composition, wherein the measured difference in storage modulus (ΔG ′) is 0.8 MPa or less. A polyvinyl aromatic compound and an organic lithium compound are reacted in a molar ratio of polyvinyl aromatic compound / lithium in the range of 0.05 to 1.0,
Preparing a polyfunctional anionic polymerization initiator,
(A) using the polyfunctional anionic polymerization initiator, copolymerizing a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene copolymer;
Reacting a compound having one or more nitrogen atoms with a silyl group substituted with two or more alkoxy groups at the active terminal of the conjugated diene copolymer;
(B) a step of polymerizing a conjugated diene compound using the polyfunctional anionic polymerization initiator to obtain a conjugated diene polymer;
Reacting the active terminal of the conjugated diene polymer with a compound having one or more nitrogen atoms and a silyl group substituted with two or more alkoxy groups;
The process for producing a modified conjugated diene rubber composition according to any one of claims 1 to 5, wherein: