JP5864903B2 - Rubber composition - Google Patents

Description

  The present invention includes a copolymer obtained by copolymerizing a specific diene monomer and a filler, and a functional group that interacts with the filler in the main chain terminal and / or main chain of the copolymer. It relates to the rubber composition introduced.

  In recent years, there has been a demand for a reduction in fuel consumption of automobiles in connection with the global movement of carbon dioxide emission regulations due to social demands for energy saving and increased concern about environmental problems. In order to meet such demands, tires have been required to reduce rolling resistance. As a technique for reducing the rolling resistance of a tire, a technique for optimizing the structure of the tire and a technique for using a material having lower heat generation than that of a conventional tire as a rubber composition have been studied.

  Among the latter, an effective one is an alkoxy containing a functional group that interacts with an inorganic filler such as silica or carbon black at the polymerization active terminal of a conjugated diene polymer obtained by anionic polymerization using organolithium. A method of modifying with a silane derivative has been proposed (see, for example, Patent Documents 1, 2, 3, and 4). In addition, a modified high cis polybutadiene rubber having a functional group that interacts with a filler is added to a rubber composition which is a crosslinked product of polybutadiene having a so-called high cis structure with a small degree of branching of the polymer main chain and high linearity. (For example, refer patent document 5).

  Thus, by controlling the dispersibility of the filler by improving the interaction between the polymer and the filler constituting the rubber composition, the rolling resistance of the tire when the rubber composition is applied to the tire, It leads to improvement in wear resistance, resistance to crack growth (referred to as crack growth resistance), and the like.

  However, from the viewpoint of the reactivity between the polymerization active terminal and a modifier that modifies the polymerization active terminal, it is difficult to modify the polymerization active terminal so that a rolling resistance meeting the requirements can be obtained. In recent years, demands for reducing fuel consumption of automobiles have become more severe, and further improvements have been demanded in the rolling resistance of tires.

JP 2001-158837 A JP 2005-232364 A JP-A-2005-290355 JP 2006-307095 A Pamphlet of International Publication No. 2006/112450

  Therefore, the present invention further improves the dispersibility of the filler by improving the interaction between the copolymer obtained by copolymerization of a specific conjugated diene monomer and the filler, and has low exothermic properties and wear resistance. An object of the present invention is to provide a rubber composition capable of improving the properties and a tire using the rubber composition.

As a result of intensive studies to achieve the above object, the present inventors have found that a copolymer of a butadiene derivative having a functional group containing a nitrogen atom and a conjugated diene hydrocarbon has a low exothermic property of the rubber composition. It was also found that the wear resistance can be improved.
The present invention has been completed based on such findings.

That is, the present invention includes the following contents.
[1] A copolymer (A) obtained by copolymerizing a conjugated diene monomer (a) represented by the formula (1) and at least a conjugated diene hydrocarbon (b);
A filler (B);
A rubber composition containing

In equation (1),
A is represented by -R1-X,
R1 is a divalent hydrocarbon group having 2 to 12 carbon atoms,
X is a functional group containing a nitrogen atom, and the nitrogen atom is directly connected to R1,
B is represented by a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms, or -R2-Y;
R2 is a divalent hydrocarbon group having 2 to 12 carbon atoms,
Y is a functional group containing a nitrogen atom, and the nitrogen atom is directly connected to R2.

  According to the present invention, by improving the interaction between a copolymer obtained by copolymerizing a specific diene monomer and a filler, the dispersibility of the filler is further improved, and low heat buildup and wear resistance are achieved. It is possible to provide a rubber composition capable of improving the rubber strength and a tire using this rubber composition.

[Rubber composition]
Hereinafter, the rubber composition according to the present invention will be described in detail.
The rubber composition according to the present invention comprises a copolymer (A) obtained by copolymerizing a conjugated diene monomer (a) represented by the formula (1) and at least a conjugated diene hydrocarbon (b). And a filler (B).

[Copolymer (A)]
<Conjugated diene monomer (a)>
As the conjugated diene monomer (a) constituting the copolymer (A) blended in the rubber composition according to the present invention, a conjugated diene monomer represented by the formula (1) can be used.

  In Formula (1), A is represented by -R1-X, R1 is a divalent hydrocarbon group having 2 to 12 carbon atoms, X contains a nitrogen atom, and the nitrogen atom is directly connected to R1. Functional group. B is a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms, or -R2-Y, R2 is a divalent hydrocarbon group having 2 to 12 carbon atoms, and Y is , A functional group which contains a nitrogen atom and which is directly connected to R2.

  The copolymer (A) is a copolymer of the conjugated diene monomer (a) represented by the formula (1), the conjugated diene hydrocarbon (b), and the aromatic vinyl compound (c). May be.

In Formula (1), X and Y are preferably at least one selected from a protected primary amino group, a protected secondary amino group, a tertiary amino group, and an imino group.
Further, either one of the protecting group for protecting X or the protecting group for protecting Y is preferably a trihydrocarbylsilyl group. Examples of the trihydrocarbylsilyl group include trimethylsilyl group, triethylsilyl group, tert-butyldimethylsilyl group. And silyl groups such as groups. Especially, it is preferable that any one of the protecting group which protects X, or the protecting group which protects Y is a trimethylsilyl group.

  The copolymer (A) forms the following structural units derived from the conjugated diene monomer (a) in the main chain. That is, a cis isomer, a trans isomer of a conjugated diene monomer represented by the formula (1), or a mixture of a cis isomer and a trans isomer. Moreover, what was connected in carbon of 2nd-position of the conjugated diene monomer represented by Formula (1).

A is represented by -R1-X, R1 is a divalent hydrocarbon group having 2 to 12 carbon atoms, X is a functional group containing a nitrogen atom, and the nitrogen atom is directly connected to R1. B is a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms, or -R2-Y, R2 is a divalent hydrocarbon group having 2 to 12 carbon atoms, and Y is , A functional group that contains a nitrogen atom, and the nitrogen atom is directly connected to R2. X and Y are preferably at least one selected from a protected primary amino group, secondary amino group, tertiary amino group, and imino group.
P, q, r, and s are arbitrary integers, and may be 0 except for at least one of them. Moreover, said structural unit may exist in the principal chain of a copolymer (A), and may exist in the terminal of a copolymer (A).

<Conjugated diene hydrocarbon (b)>
Examples of the conjugated diene hydrocarbon (b) include 1,3-butadiene, isobutylene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene 1, and the like. 3-hexadiene etc. are mentioned. These may be used alone or in combination of two or more. Among these, 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene are particularly preferable.

<Aromatic vinyl compound (c)>
Examples of the aromatic vinyl compound (c) used for copolymerization of the conjugated diene monomer (a) and the conjugated diene hydrocarbon (b) include styrene, α-methylstyrene, 1-vinylnaphthalene, 3 -Vinyl toluene, ethyl vinyl benzene, divinyl benzene, 4-cyclohexyl styrene, 2,4,6-trimethyl styrene, etc. are mentioned. These may be used alone or in combination of two or more. Of these, styrene is particularly preferred. When copolymerizing the conjugated diene monomer (a), the conjugated diene hydrocarbon (b), and the aromatic vinyl compound (c), it is easy to obtain and has advantages such as the anionic polymerization property being a living property. 1,3-butadiene and styrene are preferably used.

<Weight average molecular weight and molecular weight distribution of copolymer (A)>
The weight average molecular weight (Mw) of the copolymer (A) obtained by copolymerizing the conjugated diene monomer (a) and the conjugated diene hydrocarbon (b) is 5 × 10 ³ to 1,000 × 10 ^3. it is preferably, more preferably ^{50 × 10 3 ~1,000 × 10 3} , more preferably ^{100 × 10 3 ~800 × 10 3} . Moreover, it is preferable that molecular weight distribution (Mw / Mn) is 5 or less, and it is more preferable that it is 3 or less. By setting the weight average molecular weight of the copolymer (A) within the above range, it is possible to suppress a decrease in elastic modulus after vulcanization and an increase in hysteresis loss, and to obtain an excellent fracture resistance. Excellent kneading workability of the rubber composition containing A) is obtained.
Further, by making the molecular weight distribution of the copolymer (A) within the above range, even if the copolymer (A) is blended with the rubber composition, the workability of the rubber composition is not lowered, and the mixing is not performed. Kneading is easy and the physical properties of the rubber composition can be sufficiently improved.
The weight average molecular weight (Mw) and molecular weight distribution were measured under the following conditions using gel permeation chromatography (trade name “HLC-8120GPC”, manufactured by Tosoh Corporation) and using a differential refractometer as a detector. It is a value measured and calculated as a standard polystyrene equivalent value.
Column: Trade name “GMH-XL” (manufactured by Tosoh Corporation) 2 Column temperature: 40 ° C. Mobile phase: Tetrahydrofuran flow rate: 1.0 ml / min Sample concentration: 10 mg / 20 ml

<Glass transition temperature (Tg) of copolymer (A)>
It is preferable that the glass transition temperature (Tg) calculated | required by the differential thermal analysis method of a copolymer (A) is -105 degreeC--15 degreeC. When the glass transition temperature is within the above range, it is possible to maintain a viscosity that is easy to handle.

[Filler (B)]
The filler (B) applicable to the rubber composition according to the present invention is at least one selected from silica and carbon black. When using the rubber composition which concerns on this invention for the tread part of a tire, it is preferable that 20-120 mass parts of fillers (B) are included with respect to 100 mass parts of rubber components. If the filler (B) is 20 parts by mass or more, the reinforcing property of the rubber composition can be suitably obtained, and if the filler (B) is 120 parts by mass or less, work for producing the rubber composition This is preferable because of improved properties.

<Carbon black>
The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably ^{20 to} 160 m ² / g. This is because if it is 20 m ² / g or more, the reinforcing property of the rubber composition can be suitably secured, and if it is 160 m ² / g or less, the effect of reducing rolling resistance can be enhanced.

<Inorganic filler>
The filler (B) may be an inorganic filler instead of carbon black.
As the inorganic filler, silica is preferably used from the viewpoint of reducing rolling resistance. When silica is used, the silica fraction in the total amount of the filler is preferably 20 to 90% by mass. If it is 20% by mass or more, the effect of reducing rolling resistance can be further enjoyed, and if it is 90% by mass or less, the interaction with the copolymer (A) can be improved, and the effect of reducing rolling resistance is enhanced. be able to. The filler (B) may contain both carbon black and inorganic filler.
Silica is not particularly limited, and can be arbitrarily selected from those conventionally used as reinforcing fillers for rubber. Examples include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, etc., and these may be used alone or in combination of two or more. However, among these, preferred is wet silica which can remarkably obtain the effect of improving the fracture characteristics and the effect of achieving both wet grip properties.

<Silane coupling agent>
When silica is used as the inorganic filler, it is preferable to add a silane coupling agent for the purpose of further improving its reinforcing property and low heat build-up.
Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-sodium trisulfide). Ethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercapto Ethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarb Moyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxy Ethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl Tetrasulfide, dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide, and the like can be mentioned. Among these, bis (( - triethoxysilylpropyl) polysulfide and 3-trimethoxysilylpropyl benzothiazolyl tetrasulfide are preferable. One of these silane coupling agents may be used alone, or two or more thereof may be used in combination.

Although the compounding quantity of a silane coupling agent changes with kinds etc. of a silane coupling agent, Preferably it selects in the range of 1-20 mass% with respect to a silica. From the viewpoints of the effect as a coupling agent and the prevention of gelation, the preferred amount of the silane coupling agent is in the range of 5 to 15% by mass. When the blending amount of the silane coupling agent is less than 1% by mass, the effect as a coupling agent is not sufficiently exhibited, and when it exceeds 20% by mass, the copolymer (A) may be gelled.
Since the rubber composition according to the present invention has a functional group having a high affinity for the filler (B) in the main chain terminal and / or main chain of the copolymer (A), the silane coupling is performed. The compounding quantity of an agent can be reduced rather than usual.

[Other ingredients]
<Rubber component>
In addition to the copolymer (A) and filler (B) described above, components other than these may be blended in the rubber composition according to the present invention. The rubber component that can be blended in the rubber composition according to the present invention may be at least one selected from diene rubbers and non-diene rubbers. Examples of the diene rubber include natural rubber, isoprene rubber, styrene butadiene rubber, chloroprene rubber, and acrylonitrile butadiene rubber. Examples of non-diene rubbers include butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber, and acrylic rubber.

[Synthesis Method of Conjugated Diene Monomer (a)]
The conjugated diene monomer (a) constituting the copolymer (A) is synthesized by the following synthesis method.

(Synthesis method)
The allylic carbon of a conjugated diene compound having an alkyl substituent such as 2-methyl-1,3-butadiene or 2,3-dimethyl-1,3-butadiene was halogenated and halogenated using a known method. By reacting a conjugated diene compound with a nucleophilic reaction reagent having a desired modified functional group such as 4- (N, N-bistrimethylsilylaminopropyl) -1-magnesium bromide, N, N-bistrimethylsilylaminoalkyl is obtained. A conjugated diene monomer having a group can be obtained.

[Polymerization method of copolymer (A) 1 Anionic polymerization]
<Description of polymerization method>
The copolymer (A) is obtained by copolymerization of a conjugated diene monomer (a) and a conjugated diene hydrocarbon (b) (may include an aromatic vinyl compound (c)). The polymerization method of the copolymer (A) is not particularly limited, and a solution polymerization method, a gas phase polymerization method, and a bulk polymerization method can be used. Moreover, both a batch type and a continuous type can be applied as the polymerization mode.

  As an example of the polymerization method of the copolymer (A), anionic polymerization using an organic alkali metal compound, particularly an organic lithium compound as a polymerization initiator can be used. Specifically, in an organic solvent inert to the reaction, for example, a hydrocarbon solvent such as an aliphatic, alicyclic or aromatic hydrocarbon compound, two or more kinds of conjugated diene monomer (a), conjugated diene type A hydrocarbon (b) and an aromatic vinyl compound (c) are mixed and polymerized using an organolithium compound as a polymerization initiator.

  In the case of the solution polymerization method, the concentration of the conjugated diene monomer (a) and the conjugated diene hydrocarbon (b) in the solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass. In addition, when using an aromatic vinyl compound (c), it is preferable that the content of the aromatic vinyl compound (c) in a preparation monomer mixture shall be 0-55 mass%.

  The temperature in the solution polymerization method is preferably in the range of 0 to 150 ° C, more preferably 20 to 130 ° C. This copolymerization reaction can be carried out under generated pressure, but it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure of the reaction system can be appropriately set depending on the kind of monomer to be polymerized, the polymerization medium, the polymerization temperature, etc., but the higher the pressure, the better. Such a high-pressure environment can be realized by a method such as pressurizing the reaction system with a gas inert to the polymerization reaction.

  It is desirable that all raw materials involved in the polymerization reaction, such as a polymerization initiator, a solvent, and a monomer, are subjected to a treatment for removing reaction inhibitors such as water, oxygen, carbon dioxide, and protic compounds. Moreover, you may mix | blend a randomizer with a reaction system as needed. By blending the randomizer, the microstructure of the copolymer (A) or the composition distribution of the monomers constituting the copolymer (A) can be controlled.

After the copolymerization of the conjugated diene hydrocarbon (b) and the aromatic vinyl compound (c) proceeds, the main chain of the copolymer (A) is added by adding the conjugated diene monomer (a) to the reaction system. The conjugated diene monomer (a) can be introduced at the terminal.
At the start of polymerization, the conjugated diene monomer (a) is added to the reaction system by adding the conjugated diene monomer (a), the conjugated diene hydrocarbon (b), and the aromatic vinyl compound (c). A copolymer (A) incorporated therein can be obtained.
Further, the conjugated diene monomer (a) can be added during the progress of the polymerization reaction.
Further, after introducing the conjugated diene monomer (a) to the main chain terminal, the conjugated diene hydrocarbon (b) and the aromatic vinyl compound (c) can be further added.

After forming the main chain of the copolymer (A) by anionic polymerization, a hydrolysis reaction and a deprotection reaction may be performed. The hydrolysis reaction is preferably acid hydrolysis. As the acid compound used for the acid hydrolysis, it is preferable to combine any one of inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as carboxylic acid and phenol, and proton donating compounds such as water and alcohol. .
In this way, after completion of the hydrolysis reaction and deprotection reaction, an isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) or the like is added to the polymerization reaction system to stop the polymerization reaction. Thereafter, a solvent removal process such as steam stripping or a vacuum drying process is performed to reduce the partial pressure of the solvent by blowing water vapor. As a result, a copolymer (A) having an amino group introduced into the main chain terminal and / or main chain is obtained.

<Solvent>
As the hydrocarbon solvent, those having 3 to 8 carbon atoms are preferable. For example, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene, 2-pentene, Examples include 1-hexene, 2-hexene, benzene, toluene, xylene, and ethylbenzene. These may be used alone or in combination of two or more.

<Polymerization initiator>
As the polymerization initiator for the copolymerization reaction, one selected from alkali metals and alkaline earth metal compounds is preferably used, and alkali metals are particularly preferable. Specifically, lithium metal is preferably used. In addition to the lithium-based initiator, a general catalyst used as a polymerization initiator in anionic polymerization can be used.
It is also effective to mix halogen-containing monomers and activate halogen atoms in the polymer with an organometallic compound. For example, it is also effective to lithiate the bromine moiety of a copolymer containing an isobutylene unit and a paramethylstyrene unit to form an active site.

  The organolithium compound is not particularly limited, but hydrocarbyl lithium and lithium amide compounds are preferred. When hydrocarbyl lithium is used, a conjugated diene polymer having a hydrocarbyl group at the polymerization initiation terminal and the other terminal being a polymerization active site is obtained. When the latter lithium amide compound is used, a conjugated diene polymer having a nitrogen-containing group at the polymerization initiation terminal and the other terminal being a polymerization active site is obtained.

  As hydrocarbyl lithium, those having a hydrocarbyl group having 2 to 20 carbon atoms are preferable, for example, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, n-decyl. Examples include lithium, phenyllithium, 2-naphthyllithium, 2-butyl-phenyllithium, 4-phenyl-butyllithium, cyclohexyllithium, cyclobenthyllithium, a reaction product of diisopropenylbenzene and butyllithium, and the like. Among these, n-butyllithium is particularly preferable.

  On the other hand, examples of the lithium amide compound include lithium hexamethylene imide, lithium pyrrolidide, lithium piperide, lithium heptamethylene imide, lithium dodecamethylene imide, lithium dimethyl amide, lithium diethyl amide, lithium dibutyl amide, lithium dipropyl amide, and lithium disulfide. Heptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium-N-methylpiverazide, lithium ethylpropylamide, lithium ethylbutyramide, lithium ethylbenzylamide, lithium methylphenethylamide, etc. Is mentioned. Among these, from the viewpoint of the interaction effect on carbon black and the ability of initiating polymerization, cyclic lithium amides such as lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, and lithium dodecamethylene imide are preferable. In particular, lithium hexamethylene imide and lithium pyrrolidide are suitable.

  In general, these lithium amide compounds prepared from a secondary amino group and an organic lithium compound can be used for the polymerization, but can also be prepared in-polymerization in situ. The amount of the polymerization initiator used is preferably selected in the range of 0.2 to 20 mmol per 100 g of monomer.

<Randomizer>
The randomizer is a compound that contributes to control of the microstructure of the copolymer (A) or control of the composition distribution of the monomers constituting the copolymer (A). Examples of the microstructure control include an increase in 1,2 bonds in the butadiene moiety in the butadiene-styrene copolymer and an increase in 3,4 bonds in the isoprene polymer. As control of the monomer composition distribution, in the conjugated diene hydrocarbon-aromatic vinyl compound copolymer, butadiene-styrene copolymer, etc., the conjugated diene monomer unit, aromatic vinyl monomer unit, butadiene unit, styrene unit are For example, randomization to be dispersed.

  As the randomizer, any one of known compounds generally used as randomizers can be appropriately selected and used. Specifically, dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-bis (2-tetrahydrofuryl) -propane, triethylamine, pyridine, N-methylmorpholine, N, N, N ′, Examples thereof include ethers such as N′-tetramethylethylenediamine and 1,2-dipiperidinoethane, and tertiary amino groups. Further, potassium salts such as potassium tert-amylate and potassium tert-butoxide, and sodium salts such as sodium tert-amylate can also be used.

  These randomizers may be used alone or in combination of two or more. The amount used is preferably selected in the range of 0.01 to 1000 molar equivalents per mole of the organolithium compound.

[Polymerization method of copolymer (A) 2 coordination polymerization]
<Description of polymerization method>
The copolymer (A) can also be polymerized by coordination polymerization. The polymerization form is not particularly limited, and may be batch or continuous. In the case of coordination polymerization, it is possible to produce a copolymer (A) having a cis-1,4 bond content of 80% or more having high fracture characteristics and low exothermic properties. Specifically, two or more kinds of conjugated diene monomer (a), conjugated diene hydrocarbon (b), and aromatic vinyl compound (c) are mixed in an organic solvent inert to the reaction, and the rare earth metal is mixed. Polymerizes as a catalyst.
In the coordination polymerization reaction, the temperature of the copolymerization reaction is preferably in the range of −30 ° C. to 200 ° C., and more preferably in the range of 0 ° C. to 150 ° C. In addition, it is desirable that all raw materials involved in the polymerization reaction, such as a polymerization initiator, a solvent, and a monomer, are subjected to a treatment for removing a reaction inhibitor such as water, oxygen, carbon dioxide, and a protic compound.

<Solvent>
The solvent may be inert to the polymerization reaction. For example, butane, pentane, hexane, heptane, cyclopentane, cyclohexane, 1-butene, 2-butene, benzene, toluene, xylene, methylene chloride, chloroform, four Examples thereof include carbon chloride, trichloroethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, bromobenzene, chlorotoluene and the like.

<Polymerization initiator>
In the polymerization method 2 of the copolymer (A), as a polymerization initiator,
Component (x): a lanthanoid element-containing compound containing at least one of lanthanoid elements (rare earth elements corresponding to atomic numbers 57 to 71 in the periodic table), or a reaction product obtained by reacting a lanthanoid element-containing compound with a Lewis base ,
Component (y): an alumoxane and / or an organoaluminum compound represented by AlR ^a R ^b R ^c (wherein R ^a and R ^b may be the same or different and each represents a hydrocarbon group having 1 to 10 carbon atoms) Or a hydrogen atom, and R ^c may be the same as or different from R ^a and R ^b, and is a hydrocarbon group having 1 to 10 carbon atoms),
Component (z): a halogen-containing compound containing at least one halogen element in its molecular structure,
A catalyst composition is used.

  Two or more kinds of conjugated diene monomer (a), conjugated diene hydrocarbon (b), aromatic vinyl compound (c) using a catalyst (referred to as catalyst composition) containing component (x) to component (z) Copolymer (A) having a narrow molecular weight distribution and a high cis-1,4 bond content (80% or more) can be obtained. In addition, these catalyst compositions are less expensive than conventionally used metallocene catalysts and do not require a polymerization reaction at an extremely low temperature. For this reason, operation is simple and useful as an industrial production process.

  Component (x) is a lanthanoid element-containing compound containing at least one of lanthanoid elements (rare earth elements corresponding to atomic numbers 57 to 71 in the periodic table), or a reaction obtained by reacting this lanthanoid element-containing compound with a Lewis base. Product. Specific examples of the lanthanoid element include neodymium, praseodymium, cerium, lanthanum, gadolinium, samarium and the like. Of these, neodymium is preferred. In addition, these lanthanoid elements may be used independently and may be used in combination of 2 or more types. Specific examples of the lanthanoid element-containing compound include lanthanoid element carboxylates, alkoxides, β-diketone complexes, phosphates, phosphites, and the like. Among these, carboxylate or phosphate is preferable, and carboxylate is more preferable.

As the lanthanoid element carboxylate, a salt such as 2-hexylhexane, naphthenic acid, versatic acid [trade name, manufactured by Shell Chemical Co., Ltd., carboxylic acid having a carboxyl group bonded to a tertiary carbon atom] or the like is preferable. It is mentioned in. Specific examples of alkoxides of lanthanoid elements include compounds represented by (R ^d O) ₃ M (where M is a lanthanoid element and R ^d is a hydrocarbon group having 1 to 20 carbon atoms). Can be mentioned. Preferable examples of the alkoxy group represented by “R ^d O” include 2-ethyl-hexylalkoxy group, benzylalkoxy group and the like.

Preferred examples of the lanthanoid element β-diketone complex include acetylacetone complexes and ethylacetylacetone complexes. As lanthanoid element phosphates or phosphites, bis (2-ethylhexyl) phosphate, bis (1-methylheptyl) phosphate, mono-2-ethylhexyl 2-ethylhexylphosphonate, bis (2-ethylhexyl) Preferable examples include salts such as phosphinic acid.
Among those exemplified above, the lanthanoid element-containing compound is more preferably a neodymium phosphate or a neodymium carboxylate, and a carboxylate such as neodymium 2-ethylhexanoate or neodymium versatate. Particularly preferred.

The component (y) is an organoaluminum compound represented by alumoxane and / or AlR ^a R ^b R ^c . Alumoxane (also referred to as aluminoxane) has a structure represented by the following general formula (2) or general formula (3). Component (y) can be prepared according to Fine Chemicals, 23, (9), 5 (1994), J. Org. Am. Chem. Soc. 115, 4971 (1993) and J. Am. Am. Chem. Soc. 117, 6465 (1995), and alumoxane aggregates.

In the general formulas (2) and (3), R ^e is a hydrocarbon group having 1 to 20 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, t -A butyl group, a hexyl group, an isohexyl group, an octyl group, an isooctyl group, etc. are mentioned, Among these, a methyl group is particularly preferable. A plurality of ^Re may be the same or different. m is an integer of 2 or more, and is preferably an integer of 4 to 100.

  Specific examples of alumoxane include methylalumoxane (MAO), ethylalumoxane, n-propylalumoxane, n-butylalumoxane, isobutylalumoxane, t-butylalumoxane, hexylalumoxane, isohexylalumoxane and the like. Can be mentioned. Alumoxane can be produced by a known method. For example, trialkylaluminum or dialkylaluminum monochloride is added to an organic solvent such as benzene, toluene, xylene, and water, water vapor, water vapor-containing nitrogen gas, or copper sulfate pentahydrate or aluminum sulfate 16-hydrate. It can be produced by adding a salt having water of crystallization to react. In addition, alumoxane may be used individually by 1 type, and may be used in combination of 2 or more type.

On the other hand, specific examples of the organoaluminum compound represented by (R ^d O) ₃ M include triethylaluminum, triisobutylaluminum, diethylaluminum hydride, diisobutylaluminum hydride and the like. In addition, an organoaluminum compound may be used individually by 1 type, and may be used in combination of 2 or more types.

  Component (z) is a halogen-containing compound containing at least one halogen atom in its molecular structure, such as a reaction product of a metal halide and a Lewis base, diethylaluminum chloride, silicon tetrachloride, trimethylchlorosilane, Methyldichlorosilane, dimethyldichlorosilane, methyltrichlorosilane, ethylaluminum dichloride, ethylaluminum sesquichloride, tin tetrachloride, tin trichloride, phosphorus trichloride, benzoyl chloride, t-butyl chloride, trimethylsilyl iodide, triethylsilyl iodide, Dimethylsilyldiiodide, diethylaluminum iodide, methyl iodide, butyl iodide, hexyl iodide, octyl iodide, iodoform, diiodomethane, iodine, ben Isopropylidene iodide can be preferably exemplified.

  Metal halides that can be used in the reaction product of a metal halide and a Lewis base include magnesium chloride, manganese chloride, zinc chloride, copper chloride, magnesium iodide, manganese iodide, zinc iodide, copper iodide, and the like. Preferably mentioned. On the other hand, as the Lewis base, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, an alcohol or the like can be preferably used. Specifically, tri-2-ethylhexyl phosphate, tricresyl phosphate, acetylacetone, 2- Preferable examples include ethylhexanoic acid, versatic acid, 2-ethylhexyl alcohol, 1-decanol, and lauryl alcohol. The Lewis base is preferably reacted at a ratio of 0.01 mol to 30 mol, more preferably at a ratio of 0.5 mol to 10 mol, per 1 mol (mol) of the metal halide. When the reaction product with the Lewis base is used, the metal remaining in the polymer can be reduced.

  In addition, the mixture ratio of component (x)-(z) used as the main component of such a catalyst composition can be suitably set as needed. Component (x) is preferably used in an amount of 0.00001 mmol to 1.0 mmol, more preferably 0.0001 mmol to 0.5 mmol, based on 100 g of monomer.

  When component (y) is an alumoxane, the preferred amount of alumoxane contained in the catalyst composition can be expressed by the molar ratio of component (x) to aluminum (Al) contained in the alumoxane. That is, “component (x)”: “aluminum (Al) contained in alumoxane” (molar ratio) is preferably 1: 1 to 1: 500, more preferably 1: 3 to 1: 250. Of 1: 5 to 1: 200 is particularly preferable. On the other hand, when the component (y) is an organoaluminum compound, the preferred amount of the organoaluminum compound contained in the catalyst composition can be represented by the molar ratio of the component (x) and the organoaluminum compound. That is, “component (x)”: “organoaluminum compound” (molar ratio) is preferably 1: 1 to 1: 700, more preferably 1: 3 to 1: 500.

  Moreover, the preferable quantity of the component (z) contained in a catalyst composition can be represented by the molar ratio of the halogen atom contained in a component (z), and a component (x). That is, (halogen atom) / (component (x)) (molar ratio) is preferably 20 to 0.1, more preferably 15 to 0.2, and 8 to 0.5. Particularly preferred.

As the catalyst composition, in addition to the components (x) to (z), a catalyst composition prepared using the conjugated diene monomer (a) or the conjugated diene hydrocarbon (b) may be used as necessary. it can. For example, it can prepare by making the component (x)-component (z) melt | dissolved in the solvent react with another conjugated diene hydrocarbon and / or a nonconjugated diene hydrocarbon. The order of addition of each component may be arbitrary at the time of adjustment. However, from the viewpoint of improving the polymerization activity and shortening the polymerization initiation induction period, it is preferable to react each component in advance for aging.
The aging temperature is preferably 0 ° C to 100 ° C, more preferably 20 ° C to 80 ° C. There is no particular limitation on the aging time. Before adding a catalyst composition to a polymerization reaction system, the grade which contacts each component may be sufficient. A maturing time of 0.5 minutes or more is sufficient. The prepared catalyst composition is stable for several days.

In the coordination polymerization using the catalyst composition described above, as in the case of anionic polymerization, after the copolymerization of the conjugated diene hydrocarbon (b) and the aromatic vinyl compound (c) proceeds, By adding the conjugated diene monomer (a), the conjugated diene monomer (a) can be introduced into the main chain terminal of the copolymer (A).
At the start of polymerization, the conjugated diene monomer (a) is added to the reaction system by adding the conjugated diene monomer (a), the conjugated diene hydrocarbon (b), and the aromatic vinyl compound (c). A copolymer (A) incorporated therein can be obtained.
Further, the conjugated diene monomer (a) can be added during the progress of the polymerization reaction.
Further, after introducing the conjugated diene monomer (a) to the main chain terminal, the conjugated diene hydrocarbon (b) and the aromatic vinyl compound (c) can be further added.

  Further, after forming the main chain of the copolymer (A) by coordination polymerization, a hydrolysis reaction and a deprotection reaction may be performed as in the case of anionic polymerization.

[Rubber product]
<Preparation and use of rubber products>
In the rubber composition according to the present invention, various chemicals usually used in the rubber industry, for example, a vulcanizing agent, a vulcanization accelerator, a process oil, an anti-aging agent, as long as the object of the present invention is not impaired Agent, scorch inhibitor, zinc white, stearic acid and the like.
The rubber composition according to the present invention can be obtained by kneading using a kneader such as an open kneader such as a roll or a closed kneader such as a Banbury mixer. Furthermore, it can be applied to various rubber products by molding and vulcanizing the kneaded rubber composition.
For example, tire tires such as tire treads, under treads, carcass, sidewalls, side reinforcement rubbers, bead parts (particularly bead fillers), and applications such as anti-vibration rubbers, fenders, belts, hoses and other industrial products. Can be used.
The rubber composition according to the present invention is particularly suitable as a low fuel consumption tire, a large tire, a tread rubber for a high performance tire, and a sidewall rubber, which are excellent in balance between low heat generation, wear resistance and breaking strength. used.

(Rubber for tread)
When the rubber composition according to the present invention is used for a tread rubber, the copolymer (A) is a copolymer A having a styrene butadiene rubber as a main skeleton, and the filler (B) is silica. Is preferably used. In addition to the copolymer (A) and the filler (B), other rubber components include natural rubber, synthetic isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-α-olefin copolymer rubber, ethylene-α. -Olefin-diene copolymer rubber, acrylonitrile-butadiene rubber, chlorobrene rubber, halogenated butyl rubber, and at least one selected from copolymers of styrene having a halogenated methyl group and isobutylene in an amount of 80 to 0% by mass. Preferably, it contains 70 to 0% by mass, more preferably 60 to 0% by mass.
The tread rubber is extruded and formed as a tread member. The tread member is affixed to the base tire by a conventional method on a tire molding machine, and a green tire is formed. By vulcanizing this green tire in a vulcanizer, the tire of the present invention is obtained.

(Rubber for side wall)
Moreover, when using the rubber composition which concerns on this invention as rubber | gum for sidewalls, while using the copolymer (A) which has butadiene as a main skeleton as a copolymer (A), it is a filler (B ) Is preferably used as carbon black. In addition to the copolymer (A) and the filler (B), other rubber components similar to the tread rubber can also be included.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples. First, a method for evaluating a rubber composition according to an example will be described, and then a production example of the rubber composition will be described.

[Evaluation method]
The low heat build-up and wear resistance of the tire tread rubber composition were evaluated by the following methods.
<Abrasion resistance>
In accordance with JIS K6264, the amount of wear was measured at room temperature using a Lambourn abrasion tester, and the reciprocal of the amount of wear was calculated. The result was displayed by the index | exponent which sets the comparative example to 100. The larger the index value, the smaller the amount of wear and the better the wear resistance.
<Low exothermic property (tan δ)>
Using a viscoelasticity measuring device (Rheometrics), loss tangent (tan δ) was measured at a temperature of 50 ° C., a strain of 5%, and a frequency of 15 Hz. The result was displayed by the index | exponent which sets the comparative example to 100. A smaller index value indicates a lower exothermic property.

[Synthesis of Conjugated Diene Monomer (a)]
As the conjugated diene monomer (a) constituting the copolymer (A), 2- (N, N-bistrimethylsilylaminomethyl) -1,3-butadiene (referred to as monomer M ₁ ) and 2- [4- ( N, N-bistrimethylsilylaminobutyl)]-1,3-butadiene (referred to as monomer M ₂ ) was synthesized according to the following scheme. Hereinafter, each step S1 to S5 of the scheme will be described.

<S1: Synthesis of 3-methyl-3-sulfolene>
A glass test tube with an outer diameter of 40 mm was filled with 31.34 g (0.4601 mol) of isoprene, 22 mL of dry methanol, 1.0 g of hydroquinone (0.01 mol), a stir bar, and cooled with a dry ice / acetone bath. went.
After nitrogen substitution, the nitrogen gas was switched to sulfur dioxide (SO ₂ ) gas, and 30 g (0.46 mol) of liquid SO ₂ was collected in a glass test tube and immediately put in an autoclave and sealed. This was immersed in an oil bath, slowly heated to 85 ° C., and heated for 4 hours.
Thereafter, the autoclave was cooled to room temperature, and unreacted SO ₂ gas was released through a bubbler containing 10% NaOH aqueous solution. The obtained reaction solution was poured into 150 mL of distilled water and filtered while hot. When SO ₂ dissolved in the solution was removed by reducing the pressure with an aspirator, white crystals were precipitated. The white crystals were dissolved in distilled water and recrystallized to obtain white plate crystals.
When ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the white plate crystal were measured and analyzed, the obtained white plate crystal was 3-methylsulfolene. The yield was 78.6%, and the melting point was 63.5-65 ° C. (Reference values: yield 78-82%, melting point 63.5-64 ° C.).

¹ H-NMR (30 ° C., CDCl ₃ , CHCl ₃ standard: 7.24)
d = 5.65 (s, 1H, CH 2 -CH = C), 3.75 (s, 2H, CH 2 -S), 3.63 (s, 2H, CH-CH 2 -S), 1. 85 (s, 3H, CH ₃ )
・¹³ C-NMR (30 ° C., CDCl ₃ , CDCl ₃ standard: 77.0)
d = 134.0 (CH = C) , 117.9 (CH = C), 58.9 (CH = C-CH 2), 57.3 (CH 2 -CH = C), 18.8 (CH 3 )

<S2: Synthesis of 3-bromomethyl-3-sulfolene>
In a 1 L two-necked flask equipped with an Allen condenser, 66.09 g (0.50 mol) of 3-methylsulfolene, 88.99 g (0.50 mol) of N-bromosuccinimide (NBS), benzoyl peroxide (BPO) 6.06 g (0.025 mol), 600 mL of dry chloroform, and a stirrer were placed, immersed in an oil bath, and refluxed for a total of 20 hours.
At the beginning, the deep red reaction solution turned yellow in about 1 hour from the start of reflux and became lighter over time.
After cooling to room temperature, the precipitated succinimide was removed by filtration. Most of the chloroform was distilled off under reduced pressure and cooled in a refrigerator to precipitate the remaining succinimide. This was filtered again, and the remaining chloroform was distilled off under reduced pressure and concentrated. About 1 L of ethanol was added to the concentrated reaction solution, and the mixture was allowed to stand in a freezer. The precipitated crystals were dissolved in ethanol and recrystallized twice.
When the ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the obtained crystal were measured and analyzed, the obtained crystal was 3-bromomethylsulfolene. The yield was 20% and the melting point was 75-81 ° C. (literature value: 38%, melting point 78-84 ° C.).

¹ H-NMR (30 ° C., CDCl ₃ , CHCl ₃ standard: 7.24)
d = 6.07 (s, 1H, CH 2 -CH = C), 4.01 (s, 2H, C-CH 2 -S), 3.85 (s, 4H, CH-CH 2 -S and C -CH ₂ -Br)
・¹³ C-NMR (30 ° C., CDCl ₃ , CDCl ₃ standard: 77.0)
d = 134.4 (CH = C), 122.2 (CH = C), 57.3 (CH = CCH ₂ ), 56.6 (CH ₂ CH = C), 29.6 (CH ₂ Br)

<S3: Synthesis of 2-bromomethyl-1,3-butadiene>
In a 200 mL eggplant flask, 22.15 g (0.1049 mol) of 3-bromomethyl-3-sulfolene, 1.0 g (0.01 mol) of hydroquinone, and a stirrer were placed, and the oil bath was heated to 170 ° C. in advance. Soaked.
When 3-bromomethyl-3-sulfolene was completely dissolved in the eggplant flask, the pressure was reduced, and the crude product was collected in a trap cooled in an ice-water bath. The reaction was judged to be complete when the stirring bar stopped rotating. The crude product was washed with aqueous sodium bicarbonate and distilled water and dried over anhydrous magnesium sulfate overnight. Thereafter, the crude product was filtered and distilled under reduced pressure to obtain the product.
When the ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the obtained product were measured and analyzed, the obtained product was 2-bromomethyl-1,3-butadiene. The yield was 33.9% (document value: 30%), and the melting point was 49 ° C./40 mmHg.

¹ H-NMR (30 ° C., CDCl ₃ , CHCl ₃ standard: 7.24)
d = 6.41 (dd, 1H, J = 17.7, 11.1 Hz, CH ₂ = CHC), 5.41 (d, 1H, J = 17.7 Hz, CH = CH ₂ ), 5.38 ( s, 1H, C = CH ₂ ), 5.25 (d, 1H, CH = CH ₂ , J = 11.1 Hz), 5.23 (s, 1H, C = CH ₂ ), 4.09 (s, 2H, CH ₂ -Br)
・¹³ C-NMR (30 ° C., CDCl ₃ , CDCl ₃ standard: 77.0)
_{d = 142.4 (CH 2 = CH} ), 135.0 (C = CH 2), 120.1 (CH 2 = CH), 115.9 (C = CH 2), 30.5 (CH 2 Br)

<S4: Synthesis of 2- (N, N-bistrimethylsilylaminomethyl) -1,3-butadiene>
Under a nitrogen atmosphere, 2.2 g (0.0550 mol) of potassium hydride was placed in a 100 mL two-necked eggplant flask, washed several times with hexane to remove the oil, and then vacuum dried. A cooling tube and a dropping funnel were attached to this two-necked eggplant flask, 7 mL of dry THF was added, and the mixture was cooled in an ice-water bath. 1.94 g (0.0554 mol) of 1,1,1,3,3,3-hexamethyldisilazane (HMDS) was added dropwise, stirred for 30 minutes, and stirred at room temperature for 1 hour. Then, 5.47 g (0.0372 mol) of 2-bromomethyl-1,3-butadiene was added dropwise at 0 ° C. and stirred for 1 hour. After returning to room temperature, the mixture was further stirred for 1 hour. Hexane was added to the reaction solution for dilution, and suction filtration was performed under a nitrogen atmosphere, and the solvent was distilled off under reduced pressure and concentrated. This was distilled to obtain the product.
When ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the obtained product were measured and analyzed, the obtained product was 2- (N, N-bistrimethylsilylaminomethyl) -1,3-butadiene. (Monomer M ₁ ). The yield was 32.6% and the melting point was 39.5 ° C./3 mmHg.

¹ H-NMR (30 ° C., CDCl ₃ , CHCl ₃ standard: 7.24)
d = 6.41 (dd, 1H, J = 17.8, 11.2 Hz, CH ₂ = CHC), 5.16 (s, 1H, C = CH ₂ ), 5.14 (d, 1H, J = 17.8 Hz, CH = CH ₂ ), 5.10 (s, 1 H, C = CH ₂ ), 4.98 (d, 1 H, J = 11.2 Hz, CH = CH ₂ ), 3.57 (s, _{2H, CCH 2 -N), 0.07} (s, 18H, Si-CH 3)
・¹³ C-NMR (30 ° C., CDCl ₃ , CDCl ₃ standard: 77.0)
d = 147.2 (C = CH ₂ ), 137.9 (CH ₂ = CH), 115.8 (CH ₂ = CH), 111.8 (C = CH ₂ ), 45.2 (CH ₂ N) , 1.6 (SiCH ₃ )

<S5: Synthesis of 2- [4- (N, N-bistrimethylsilylaminobutyl)]-1,3-butadiene>
(1) Synthesis of N, N-bistrimethylsilyl-3-bromopropylamine Under a nitrogen atmosphere, a 300 mL two-necked flask was charged with 10 g (0.046 mol) of 3-bromopropylamine hydrobromide and 15.28 g of triethylamine. (0.151 mol) and 150 mL of dichloromethane were added. A dichloromethane solution (25 mL) of 10.97 g (0.101 mol) of chlorotrimethylsilane was added dropwise thereto over about 1 hour. After completion of the dropwise addition, the mixture was stirred overnight. The hydrochloride of amine triethylamine to be purified using Hyflo Supercel was filtered, concentrated under reduced pressure and dried to obtain a crude product as a pale yellow liquid. This was distilled under reduced pressure to obtain a purified product.
When the ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the obtained purified product were measured and analyzed, the purified product was N, N-bistrimethylsilyl-3-bromopropylamine. The yield was 66.0% and the melting point was 48 ° C./2 mmHg.

¹ H-NMR (25 ° C., CDCl ₃ , CHCl ₃ standard: 7.24)
d = 3.30 (t, 2H, CH 2 Br), 2.89 (m, 2H, CH 2 N), 1.88 (m, 2H, CH 2 CH 2 CH 2), 0.08 (SiCH 3 )
・¹³ C-NMR (25 ° C., CDCl ₃ , CDCl ₃ standard: 77.0)
d = 44.3 (CH ₂ N), 37.7 (CH ₂ CH ₂ CH ₂ ), 31.0 (CH ₂ Br), 2.1 (SiCH ₃ )

(2) (Synthesis of 2- [4- (N, N-bistrimethylsilylaminobutyl)]-1,3-butadiene)
Under a nitrogen atmosphere, 1.38 g (0.057 mol) of Mg was added to a three-necked flask, and the whole flask was warmed with a dryer for about 10 minutes. An Allen condenser tube and a dropping funnel were attached to this, and 55 mL of THF was added. While vigorously stirring, add 2 to 3 drops of methyl iodide as an activator, and cool the flask with an ethanol / dry ice bath and 8.0 g (0.028 mol) of N, N-bistrimethylsilyl-3-bromopropylamine In THF (10 mL) was added dropwise.
After dropping, the reaction was followed by GC, and when the peak of N, N-bistrimethylsilyl-3-bromopropylamine disappeared, stirring was stopped. After allowing the solid to settle, the supernatant was transferred to a dropping funnel by decantation, and a THF solution (50 mL) of 4.16 g (0.028) of 2-bromomethyl-1,3-butadiene that had been cooled in an ice-water bath in advance and Li A THF solution (10 mL) of 8.0 g (0.028 mol) of -3-bromopropylamine was added dropwise. After the dropwise addition, the reaction was followed by GC, and the stirring was stopped when the peak of N, N-bistrimethylsilyl-3-bromopropylamine disappeared. After allowing the solid to settle, the supernatant liquid is transferred to a dropping funnel by decantation, and a THF solution (50 mL) of 2.16 g (0.028) of 2-bromomethyl-1,3-butadiene that has been cooled in an ice-water bath in advance and LiCuCl. _The solution was added dropwise to a mixed solution of ₄ in THF (0.15M, 20 mL). After dropping, the reaction was followed by GC, and when the component ratio in the flask ceased to change, the reaction was terminated and suction filtration was performed. Filtration was concentrated by an evaporator and purified by distillation several times. Finally, the mixture was stirred in the presence of LiAlH ₄ to reduce bromide and then distilled under reduced pressure to obtain a product.
When the ¹ H-NMR spectrum and ¹³ C-NMR spectrum of the obtained product were measured and analyzed, the product was 2- [4- (N, N-bistrimethylsilylaminobutyl)]-1,3- Butadiene (monomer M ₂ ). The yield was 52% and the melting point was 56 to 58 ° C./2 mmHg.

¹ H-NMR (25 ° C., CDCl ₃ , CHCl ₃ standard: 7.24)
d = 6.35 (dd, 1H, J = 10.7, 17.5 Hz, CH ₂ = CH), 5.19 (d, 1H, J = 17.5 Hz, CH ₂ = CH), 5.03 ( d, 1H, J = 10.7 Hz, CH ₂ = C), 4.98 (s, 1H, C = CH ₂ ), 4.95 (s, 1H, C = CH ₂ ), 2.73 (t, 2H, CH ₂ N), 2.17 (t, 2H, CCH ₂ CH ₂ ), 1.37 (m, 4H, CH ₂ CH ₂ CH ₂ N and CH ₂ CH ₂ CH ₂ N), 0.06 ( s, 18H, SiCH ₃ )

[Production of copolymer]
<Example of production of copolymer by anionic polymerization>
"Preparation Example 1: Styrene-butadiene rubber obtained by introducing a monomer M ₂ in the main chain terminal (copolymer A1)"
Add 1,3-butadiene in cyclohexane solution and styrene in cyclohexane solution to an 800 mL pressure-resistant glass container that has been dried and purged with nitrogen to give 60 g of 1,3-butadiene and 15 g of styrene. Then, 0.29 mmol of 2-bis (2-tetrahydrofuryl) -propane and 0.57 mmol of n-butyllithium were added, followed by polymerization at 50 ° C. for 1.5 hours. The polymerization conversion at this time was almost 100%. Subsequently, a cyclohexane solution containing 0.51 mmol of monomer M ₂ was added to the polymerization reaction system and reacted at 50 ° C. for 0.5 hour. Thereafter, 0.5 mL of a 5 wt% isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer A1.

"Preparation Example 2: Styrene-butadiene rubber obtained by introducing a monomer M ₂ in the main chain (copolymer A2)"
To an 800 mL pressure-resistant glass container that has been dried and purged with nitrogen, a cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene are added so as to be 60 grams of 1,3-butadiene and 15 grams of styrene, and monomer M ₂ is added. After adding 1.71 mmol and 0.29 mmol of 2,2-bis (2-tetrahydrofuryl) -propane, and further adding 0.57 mmol of n-butyllithium, polymerization was carried out at 50 ° C. for 1.5 hours. It was. The polymerization conversion at this time was almost 100%. Thereafter, 0.5 mL of a 5 wt% isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer A2.

"Preparation Example 3: Styrene-butadiene rubber obtained by introducing a monomer M ₂ in the main chain and terminal (copolymer A3)"
To an 800 mL pressure-resistant glass container that has been dried and purged with nitrogen, a cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene are added so as to be 60 grams of 1,3-butadiene and 15 grams of styrene, and monomer M ₂ is added. 1.20 mmol, 2,2-bis (2-tetrahydrofuryl) -propane (0.29 mmol) was added, and 0.57 mmol of n-butyllithium was added, followed by polymerization at 50 ° C. for 1.5 hours. It was. The polymerization conversion at this time was almost 100%. Subsequently, a cyclohexane solution containing 0.51 mmol of monomer M ₂ was added to the polymerization reaction system and reacted at 50 ° C. for 0.5 hour. Thereafter, 0.5 mL of a 5 wt% isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer A3.

"Preparation Example 4: styrene-butadiene rubber obtained by introducing a monomer M ₁ in the main chain or terminal (copolymer R1)"
Polymerization of copolymer R1 was attempted according to Production Example 1 except that a cyclohexane solution containing 0.51 mmol of monomer M ₁ was added to the polymerization reaction system.
However, a styrene butadiene rubber (copolymer R1) in which the monomer M ₁ is introduced into the main chain or at the end of the main chain could not be obtained. It is considered that the bistrimethylsilylamino group of the monomer M ₁ is eliminated.

<< Production Example 5: Styrene butadiene rubber containing no monomer M ₂ in the main chain and at the terminal (copolymer P1) >>
Add 1,3-butadiene in cyclohexane solution and styrene in cyclohexane solution to a dry, nitrogen-substituted 800 mL pressure-resistant glass container so that 1,3-butadiene 60 gram and styrene 15 gram. Bis (2-tetrahydrofuryl) -propane (0.29 mmol) was added, and 0.57 mmol of n-butyllithium was further added, followed by polymerization at 50 ° C. for 1.5 hours. The polymerization conversion at this time was almost 100%. Thereafter, 0.5 mL of a 5 wt% isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer P1.

<Production of copolymer by coordination polymerization>
"Preparation Example 6: butadiene rubber obtained by introducing a monomer M ₂ at the end (the copolymer A4)"
(Adjustment of catalyst composition)
In a 100 mL pressure-resistant glass container that has been dried and purged with nitrogen, 7.11 g of cyclohexane solution of butadiene (15.2 wt%), 0.59 mL of cyclohexane solution of neodymium neodecanoate (0.56 M), methylaluminoxane MAO (East Soda-Aczo PMAO) in toluene solution (aluminum concentration: 3.23M) 10.32 mL, diisobutylaluminum hydride (Kanto Chemical) in hexane solution (0.90 M) in 7.77 mL were sequentially added, and then at room temperature for 2 minutes. After aging, 1.45 mL of a hexane solution (0.95 M) of chlorinated diethylaluminum (manufactured by Kanto Chemical Co., Inc.) was added, and aging was performed for 15 minutes with occasional stirring at room temperature. The concentration of neodymium in the solution of the catalyst composition thus obtained was 0.011 M (mol / liter).
(Polymerization of copolymer)
A 800 mL pressure-resistant glass container that had been dried and purged with nitrogen was charged with a cyclohexane solution of butadiene and cyclohexane, respectively, and 400 g of a cyclohexane solution of 12.5 wt% of butadiene was charged. Next, 1.70 mL (0.020 mmol of neodymium conversion) of the prepared catalyst composition was added, and polymerization was performed at 50 ° C. for 1.5 hours. The polymerization conversion at this time was almost 100%. Subsequently, a cyclohexane solution containing 0.50 mmol of monomer M ₂ was added to the polymerization reaction system and reacted at 50 ° C. for 0.5 hour. Thereafter, 0.5 mL of a 5 wt% isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer A4.

"Preparation Example 7: butadiene rubber obtained by introducing a monomer M ₂ in the main chain (copolymer A5)"
A 800 mL pressure-resistant glass container that had been dried and purged with nitrogen was charged with a cyclohexane solution of butadiene and cyclohexane, respectively, and 400 g of a cyclohexane solution of 12.5 wt% of butadiene was charged. Next, a cyclohexane solution containing 1.50 mmol of monomer M ₂ was added, and 1.70 mL of a catalyst solution prepared in the same manner as in Production Example 6 (0.020 mmol in terms of neodymium) was added, followed by polymerization at 50 ° C. for 1.5 hours. Went. The polymerization conversion at this time was almost 100%. Thereafter, 0.5 mL of an isopropanol 5% by weight solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer A5.

"Production Example 8: butadiene rubber introduced a monomer M ₁ in the main chain or terminal (copolymer R2)"
To the polymerization reaction system, except that the monomers M ₁ was added a cyclohexane solution containing 0.50 mmol attempted polymerization of the copolymer R2 accordance Preparation Example 6.
However, a butadiene rubber (copolymer R2) in which the monomer M ₁ is introduced into the main chain or at the end of the main chain could not be obtained. It is considered that the bistrimethylsilylamino group of the monomer M ₁ is eliminated.

"Production Example 9: butadiene rubber containing no monomer M ₂ in the main chain and terminal (copolymer P2)"
A 800 mL pressure-resistant glass container that had been dried and purged with nitrogen was charged with a cyclohexane solution of butadiene and cyclohexane, respectively, and 400 g of a cyclohexane solution of 12.5 wt% of butadiene was charged. Next, 1.70 mL (0.020 mmol in terms of neodymium) of a catalyst solution prepared in the same manner as in Production Example 4 was added, and polymerization was performed at 50 ° C. for 1.5 hours. The polymerization conversion at this time was almost 100%. Thereafter, 0.5 mL of a 5 wt% isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) was added to stop the reaction, followed by drying according to a conventional method to obtain a copolymer P2.

[Examples 1-8, Comparative Examples 1-3]
Copolymers A1 to A5 and Copolymers P1 and P2 produced according to the above production examples were blended according to the blending recipe shown in Table 1, and rubber compositions of Examples 1 to 8 and Comparative Examples 1 to 3 were produced. .
Examples 1 to 3 are rubber compositions suitable as tread rubber because they use a copolymer having styrene butadiene rubber as the main skeleton and carbon black as a filler. In addition, Examples 4 to 5 are rubber compositions suitable as tread rubber because they use a copolymer having a styrene butadiene rubber as a main skeleton and silica as a filler. On the other hand, Examples 7 and 8 are rubber compositions suitable as rubber for sidewalls because a copolymer having butadiene rubber as a main skeleton is used and carbon black is used as a filler.

[note]
* 1 HAF, manufactured by Asahi Carbon Co., Ltd., trade name “Asahi # 70”
* 2 Product name “Nipsil AQ” manufactured by Tosoh Silica Corporation
* 3 N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine, manufactured by Ouchi Shinsei Kagaku Co., Ltd., trade name “NOCRACK 6C”
* 4 Bis (3-triethoxysilylpropyl) tetrasulfide, manufactured by Degussa, trade name “Si69”
* 5 N, N'-Diphenylguanidine, manufactured by Sanshin Chemical Industry Co., Ltd., trade name "Sunceller DG"
* 6 Dibenzothiazyl sulfide, manufactured by Ouchi Shinsei Kagaku Co., Ltd., trade name “Noxeller DM-P”
* 7 Nt-Butyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Kagaku Co., Ltd., trade name “Noxeller NS-P”

The rubber compositions of Examples 1 to 8 and Comparative Examples 1 to 3 were vulcanized at 160 ° C. for 15 minutes to prepare sample pieces, and based on the evaluation method described above, the low exothermic properties and resistance of the rubber compositions were obtained. Abrasion was evaluated. The results are shown in Tables 2-4.
About Examples 1-3, it represented by the index | exponent which makes the reciprocal number of tan-delta of the comparative example 1 100. About Examples 4-6, it represented by the index | exponent which makes the reciprocal number of tan-delta of the comparative example 2 100. Examples 7 and 8 are indicated by an index in which the reciprocal of tan δ of Comparative Example 3 is 100. It shows that the low exothermic property of a tire is excellent, so that an index value is small. Moreover, about Examples 1-3, it displayed with the index | exponent which makes the reciprocal number of the abrasion loss of the comparative example 1 100. FIG. About Examples 4-6, it displayed with the index | exponent which makes the reciprocal number of the abrasion loss of the comparative example 2 100. FIG. Examples 7 and 8 are indicated by an index with the reciprocal of the wear amount of Comparative Example 3 being 100. The larger the index value, the smaller the amount of wear and the better the wear resistance.

Rubber compositions of Examples 1 to 3, it includes a copolymer A1~A3 polymerized by anionic polymerization of the monomers M _2, the rubber composition of Comparative Example 1, having a modified group at the terminal and the main chain Contains no copolymer P1.
As shown in the results in Table 2, it was found that the rubber compositions of Examples 1 to 3 were superior to the rubber composition of Comparative Example 1 in low heat buildup and wear resistance. Monomer M ₂ of the anionic polymerization by polymerized copolymer A1~A3 is favorably interact with carbon black (HAF), it is believed to be improved dispersibility of carbon black (HAF).

Rubber compositions of Examples 4-6 includes a copolymer A1~A3 polymerized by anionic polymerization of the monomers M _2, the rubber composition of Comparative Example 2 contains a copolymer P1.
As shown in the results of Table 3, it was found that the rubber compositions of Examples 4 to 6 were superior to the rubber composition of Comparative Example 2 in low heat buildup and wear resistance. Copolymers A1 to A3 prepared by anionic polymerization of monomer M ₂ are considered to interact well with silica (AQ) and improve the dispersibility of silica (AQ).

Rubber compositions of Examples 7 and 8, the copolymer made by coordination polymerization of monomers M ₂ A4, includes a A5, the rubber composition of Comparative Example 3 contains a copolymer P2 .
As shown in the results in Table 4, it was found that the rubber compositions of Examples 7 and 8 were superior to the rubber composition of Comparative Example 3 in low heat buildup and wear resistance. Copolymers A4 and A5 prepared by coordination polymerization of monomer M ₂ are considered to interact well with carbon black (HAF) and improve the dispersibility of carbon black (HAF).

As described in Production Examples 4 and 8, the styrene butadiene rubber in which the monomer M ₁ (2- (N, N-bistrimethylsilylaminomethyl) -1,3-butadiene) was introduced into the main chain or at the end of the main chain. (Copolymers R1 and R2) could not be produced. The following reasons can be considered for this. That is, the monomer M ₁ (2- (N, N-bistrimethylsilylaminomethyl) -1,3-butadiene) is a group linked to the 2-position carbon of 1,3-butadiene, that is, of the formula (1) The carbon number of R1 is 1 (or the carbon number of R2 of B is 1). Thus, when the number of carbon atoms of the group linked to the 2-position carbon of 1,3-butadiene is smaller than 2, it is considered that the elimination reaction in which the X group is eliminated from the main chain is promoted. It is done. The number of carbon atoms of the group linked to the carbon at the 2-position of 1,3-butadiene is 2 or more, and the larger the number, the less likely the elimination reaction will occur, which is preferable.

  Therefore, when A in the following formula (1) is -R1-X, R1 is preferably a divalent hydrocarbon group having 2 to 12 carbon atoms, and when B is -R2-X, R2 is A divalent hydrocarbon group having 2 to 12 carbon atoms is preferred.

Claims (16)

A copolymer (A) obtained by copolymerizing a conjugated diene monomer (a) represented by the formula (1) and at least a conjugated diene hydrocarbon (b);
A filler (B);
A rubber composition containing
In equation (1),
A is represented by -R1-X,
R1 is a divalent hydrocarbon group having 2 to 12 carbon atoms,
X is a functional group containing a nitrogen atom, and the nitrogen atom is directly connected to R1,
B is represented by a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms, or -R2-Y;
R2 is a divalent hydrocarbon group having 2 to 12 carbon atoms,
Y is a functional group containing a nitrogen atom, and the nitrogen atom is directly connected to R2. And a conjugated diene monomer, wherein the copolymer (A) is represented by the formula (1), and the conjugated diene hydrocarbon (b), according to claim 1 which is a copolymer of an aromatic vinyl compound (c) The rubber composition as described in 2.   The rubber composition according to claim 1 or 2, wherein the conjugated diene hydrocarbon is 1,3-butadiene.   The X and Y are at least one selected from a protected primary amino group, a protected secondary amino group, a tertiary amino group, and an imino group, respectively. The rubber composition as described in 2.   The rubber composition according to any one of claims 1 to 4, wherein either the protecting group for protecting X or the protecting group for protecting Y is a trihydrocarbylsilyl group.   The rubber composition according to claim 5, wherein either the protecting group for protecting X or the protecting group for protecting Y is a trimethylsilyl group.   The rubber composition according to any one of claims 1 to 6, wherein an alkali metal compound or an alkaline earth metal compound is used as a polymerization initiator for a copolymerization reaction to obtain the copolymer (A). As a polymerization initiator for a copolymerization reaction to obtain the copolymer (A),
Component (x): a lanthanoid element-containing compound containing at least one of lanthanoid elements (rare earth elements corresponding to atomic numbers 57 to 71 in the periodic table), or a reaction product obtained by reacting a lanthanoid element-containing compound with a Lewis base ,
Component (y): an alumoxane, and / or an organoaluminum compound represented by AlR ^a R ^b R ^c (wherein R ^a and R ^b may be the same or different, and are a hydrocarbon group having 1 to 10 carbon atoms) Or a hydrogen atom, and R ^c may be the same as or different from R ^a and R ^b, and is a hydrocarbon group having 1 to 10 carbon atoms),
Component (z): a halogen-containing compound containing at least one halogen element in its molecular structure,
The rubber composition according to any one of claims 1 to 6, wherein a catalyst composition having the following is used.   The rubber composition according to any one of claims 1 to 8, wherein the filler (B) is at least one selected from silica and carbon black.   The rubber composition according to any one of claims 1 to 9, wherein at least one selected from natural rubber, diene rubber containing isoprene rubber, and non-diene rubber containing butyl rubber is further blended.   The rubber composition according to any one of claims 1 to 10, wherein the conjugated diene monomer (a) is introduced into a main chain terminal and a main chain of the copolymer (A). The rubber composition according to any one of claims 1 to 11, wherein the copolymer (A) has a weight average molecular weight (Mw) of 5 x 10 ³ to 1,000 x 10 ³ .   The rubber composition according to any one of claims 1 to 12, wherein the copolymer (A) has a molecular weight distribution (Mw / Mn) of 5 or less.   The rubber composition according to any one of claims 1 to 13, wherein the conjugated diene monomer (a) is 2- [4- (N, N-bistrimethylsilylaminobutyl)]-1,3-butadiene. .   A tire using the rubber composition according to any one of claims 1 to 14 for a tread.   A tire using the rubber composition according to any one of claims 1 to 14 as a sidewall.