JP2016014122A - Method for producing modified conjugated diene-based polymer, modified conjugated diene-based polymer, modified conjugated diene-based polymer composition, and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a modified conjugated diene-based polymer which has a high ratio of 1,4-cis bonds and a high rate of modification, and provides a tire having excellent fuel-saving property, filler dispersibility, and abrasion resistance.SOLUTION: The method for producing a modified conjugated diene-based polymer comprises: a step (1) of obtaining a conjugated diene-based polymer by polymerizing a conjugated diene-based monomer by using a coordination polymerization initiator; and a step (2) of reacting the conjugated diene-based polymer with a compound A having 4 or more alkoxy groups bound to a silyl group, a tertiary amino group, and an ester group. Also provided is the method for producing a modified conjugated diene-based polymer where the coordination polymerization initiator comprises an organic compound of a lanthanum series metal element.

Description

  The present invention relates to a method for producing a modified conjugated diene polymer, a modified conjugated diene polymer, a modified conjugated diene polymer composition, and a tire.

In recent years, demands for reducing fuel consumption of automobiles are becoming more severe in connection with social demands for energy saving.
In order to meet such demands, further reduction in rolling resistance is also demanded for tire performance.
As a method for reducing the rolling resistance of the tire, there is a method of optimizing the tire structure, and the method using a material with less heat generation as the rubber composition is the most common.

In order to obtain such a rubber composition having a low exothermic property, a silica filler is conventionally added to a rubber-like polymer.
However, the rubbery polymer and the silica usually have a problem that since the interaction is very weak, the silica is difficult to disperse and the torque is large during the kneading process.

  As a rubbery polymer that solves the problems related to the interaction with silica, an organolithium compound is used as a polymerization initiator, and the polymerization active terminal of a conjugated diene polymer obtained by anionic polymerization of a conjugated diene monomer is modified. Modified conjugated diene polymers have been proposed.

On the other hand, as a raw material rubber for tires, a conjugated diene polymer having a 1,4-cis bond such as cis 1,4-polybutadiene is generally used as a conjugated diene polymer.
For example, tire treads are used to improve wear resistance, mechanical properties, and flexibility at low temperatures, and because they have excellent resistance to flex cracking, they are widely used as raw material rubber on sidewalls. It is used.

However, a conjugated diene polymer having a 1,4-cis bond is polymerized using an organolithium compound as a polymerization initiator, the polymerization active terminal is modified to obtain a modified conjugated diene polymer, and this is combined with silica. The combined rubber composition is rarely used for tire sidewalls, treads, and carcass.
Further, the modification effect in the rubber composition containing silica is not always sufficient. In particular, a rubber composition containing a modified conjugated diene polymer having a 1,4-cis bond has almost no modification effect by adding silica.

  Therefore, in order to solve such drawbacks, the active terminal of a conjugated diene polymer having a high cis content obtained by using a rare earth catalyst is reacted with a predetermined alkoxysilane derivative, and a functional group that interacts with the filler. A technique for obtaining a terminally modified modified conjugated diene polymer by introducing a group and a technique for adding a condensation accelerator to a reaction system in modification with the alkoxysilane derivative have been proposed (for example, Patent Documents). 1-4.)

International Publication No. 03/046020 Pamphlet JP 2013-506740 A JP2013-177521A JP 2005-8870 A

The conjugated diene polymer having a high cis content obtained by using the rare earth catalyst described above is a filler used when the polymerization is stopped by adding a known polymerization terminator to the polymerization system and reacting with the active terminal. Functional groups can be introduced into the polymer.
However, the conjugated diene polymer having a high cis content is not sufficiently reactive at the active end, and has a reactivity to the functional group to be introduced in the modification step due to the influence of the coordination compound around the active end. not enough. Therefore, there is a problem that the type of functional group of the modifying agent affects the modification rate of the modification reaction.

In the conventional techniques such as Patent Documents 1 to 3, the modification rate of the modified conjugated diene polymer having a 1,4-cis bond cannot be sufficiently increased, and therefore, fuel saving, filler dispersibility, and There is also room for improvement in wear resistance.
In particular, when a lanthanum series metal compound is used as a polymerization initiator in a polymerization reaction of a conjugated diene polymer, it tends to be difficult to achieve a high modification rate.
Further, the technique of Patent Document 4 proposes a modified conjugated diene polymer obtained by adding a condensation accelerator to the reaction system when the active end of the conjugated diene polymer is reacted with the alkoxysilane derivative. However, there is a problem that the modification rate of the modified conjugated diene polymer cannot be made sufficiently high.

  In view of the above-described problems of the prior art, in the present invention, the ratio of 1,4-cis bonds is high and the modification rate is high, and the modification is excellent in fuel saving, filler dispersibility, and wear resistance. It aims at providing the manufacturing method which can obtain a conjugated diene type polymer simply, the modified conjugated diene type polymer obtained by the said manufacturing method, a modified conjugated diene type polymer composition, and a tire.

As a result of intensive studies in view of the problems of the prior art, the present inventors have used a conjugated diene having a high 1,4-cis bond ratio by using an amino group-containing ester compound having a specific structure as a modifier. It has been found that a functional group can be efficiently introduced into a polymer and a modified conjugated diene polymer having a high modification rate can be obtained, and the present invention has been completed.
That is, the present invention is as follows.

[1]
Step (1): Using a coordination polymerization initiator, polymerizing a conjugated diene monomer to obtain a conjugated diene polymer,
Step (2): a step of reacting the conjugated diene polymer with four or more alkoxy groups bonded to a silyl group and a compound A containing a tertiary amino group and an ester group;
A process for producing a modified conjugated diene polymer.
[2]
The method for producing a modified conjugated diene polymer according to [1], wherein the coordination polymerization initiator contains an organic compound of a lanthanum series metal element.
[3]
The method for producing a modified conjugated diene polymer according to [1] or [2], wherein the compound A is represented by the following formula (1).

・・・（１）

... (1)

(In the formula ^(1), R 1 ~R ⁵ are each independently an alkyl group having a carbon 1 to 20, or an aryl group having 6 to 20 carbon atoms, R ⁶ to R ⁸ is 1 to 20 carbon atoms Represents an alkylene group, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, and the sum of m and r is 4 or more.)

[4]
A modified conjugated diene polymer obtained by the production method according to any one of [1] to [3].
[5]
The modified conjugated diene polymer according to [4], which is represented by the following formula (2) or (3).

・・・（２）

... (2)

(In the formula (2), P is a conjugated diene polymer having a 1,4-cis content of 80 mol% or more,
R ^{2 to} R ⁵ each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,
R ^{6 to} R ⁸ represent an alkylene group having 1 to 20 carbon atoms, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, m and r Is 4 or more. )

・・・（３）

... (3)

(In the formula (3), P is a conjugated diene polymer having a 1,4-cis content of 80 mol% or more,
R ^{2 to} R ⁵ each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,
R ^{6 to} R ⁸ represent an alkylene group having 1 to 20 carbon atoms, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, m and r Is 4 or more. )

[6]
100 parts by mass of a rubber component containing 10 parts by mass or more of the modified conjugated diene polymer according to [4] or [5],
0.5 to 300 parts by mass of a silica-based inorganic filler,
A modified conjugated diene polymer composition.
[7]
A tire comprising the modified conjugated diene polymer composition according to [6].

  According to the present invention, a modified conjugated diene polymer having a high 1,4-cis bond ratio and a high modification rate, excellent fuel economy, filler dispersibility, and abrasion resistance can be easily obtained. A modified conjugated diene polymer, a modified conjugated diene polymer obtained by the production method, a modified conjugated diene polymer composition containing the modified conjugated diene polymer, and a tire are obtained.

Hereinafter, a 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 following embodiment, and can be implemented with various modifications within the scope of the gist.

[Method for producing modified conjugated diene polymer]
The method for producing a modified conjugated diene polymer of the present embodiment includes a step (1) (polymerization step) of obtaining a conjugated diene polymer by polymerizing a conjugated diene monomer using a coordination polymerization initiator. And a step (2) (modification step) of reacting the conjugated diene polymer with a compound A containing four or more alkoxy groups bonded to a silyl group and a tertiary amino group and an ester group.
By carrying out the above steps (1) and (2), functional groups can be introduced at the ends of the conjugated diene polymer having a high 1,4-cis bond ratio, and the modification has a high modification rate. A conjugated diene polymer can be easily produced.

(Process (1))
In (Step 1), a conjugated diene monomer is polymerized using a coordination polymerization initiator to obtain a conjugated diene polymer.
<Coordination polymerization initiator>
In this embodiment, various transition metal compounds can be used as a coordination polymerization initiator for polymerizing a conjugated diene monomer.
By using it as a polymerization initiator for a transition metal compound, a conjugated diene polymer having a high 1,4-cis content can be obtained.
The transition metal compound to be used is not limited to the following as long as it can initiate the polymerization reaction of the conjugated diene monomer, and (a) a heavy metal compound capable of coordination polymerization. A composite catalyst comprising a transition metal compound or an organic compound of a lanthanum series metal element, (b) an organoaluminum compound, and (c) a halogen-containing Lewis acid compound is preferable.
A conjugated diene polymer can be obtained by bulk polymerization or solution polymerization of a conjugated diene monomer in a hydrocarbon solvent in the presence of this composite catalyst.

Examples of the heavy metal compound (a) capable of coordination polymerization include a transition metal compound or an organic compound of a lanthanum series metal element as described above.
Examples of the transition metal compound include, but are not limited to, periodic groups such as Group 4 transition metal compounds (eg, CpTiCl ₃ ) such as titanium and zirconium, and vanadium, niobium, and tantalum. Table Group 5 transition metal compounds, Group 6 transition metal compounds such as chromium (for example, anhydrous CrCl ₂ ), Group 9 or 10 transition metal compounds such as cobalt, nickel (for example, cobalt octate, bis (cycloocta Diene) nickel).
Examples of the organic compound of the lanthanum series metal element include, but are not limited to, for example, a lanthanoid-aluminum crosslinked complex compound represented by the following formulas (4) and (5) or a formula: LnY ₃ . The compound which is made is mentioned.

・・・（４）

... (4)

・・・（５）

... (5)

In formula (4) and formula (5), Ln represents a lanthanum series metal element, and R ^{41 to} R ⁴⁴ and R ^{51 to} R ⁵⁴ may be the same or different, and each represents a hydrogen atom or a carbon number of 1 to 8 Selected from the group consisting of a hydrocarbon group having 1 to 8 carbon atoms, an alkylsilyl group having 1 to 8 carbon atoms, an alkyloxy group having 1 to 8 carbon atoms, a dialkylamide group having 1 to 8 carbon atoms, and an aryl group having 6 to 8 carbon atoms. Any one kind is shown.

In the formula: LnY ₃ , Ln represents a lanthanum series metal element as described above, and Y represents an acid residue.
As the lanthanum series metal element of Ln, specifically, as the lanthanum series elements of the periodic table of atomic numbers 57 to 71, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprodium Holmium, erbium, thulium, ytterbium and lutetium.
Among these, lanthanum, cerium, praseodymium, neodymium and gadolinium are preferable from the viewpoint of polymerization activity, and neodymium is more preferable from the viewpoint of the balance between polymerization activity and industrial availability.
Further, in the formula: LnY ₃ , Y represents an acid residue, and is an organic salt that is an alcohol, phenol, thioalcohol, thiophenol, amine, carboxylic acid, organic phosphoric acid, or organic phosphorous acid. It is preferable from the viewpoint of solubility in a solvent.

Furthermore, examples of the organic compound of the lanthanum series metal element include an alcohol compound (alkoxide) of the lanthanum series metal element and a phenol compound (phenoxide).
Examples of alcohol compounds (alkoxides) and phenolic compounds (phenoxides) of lanthanum series metal elements include, but are not limited to, compounds represented by the formula: Ln- (ORa) ₃ .
Here, Ra represents a hydrocarbon group, and from the viewpoint of ease of handling, an alkyl group, an alkenyl group, an alkyl-substituted or alkenyl-substituted phenyl group, or an alkyl-substituted or alkenyl-substituted naphthyl group having 1 to 40 carbon atoms Is preferred.
The alkyl group and alkenyl group may be linear, branched or cyclic. Specific examples of preferable alcohol and phenol used for alkoxide and phenoxide include 2-ethyl-hexyl alcohol, oleyl alcohol, stearyl alcohol, nonylphenol, benzine alcohol and the like.

Furthermore, examples of the organic compound of a lanthanum series metal element include a thioalcohol compound (thioalkoxide) of a lanthanum series metal element and a thiophenol compound (thiophenoxide).
Examples of the thioalcohol compound (thioalkoxide) and the thiophenol compound (thiophenoxide) of the lanthanum series metal element include, but are not limited to, for example, a compound represented by the formula Ln (SRb) ₃ Can be mentioned.
Here, Rb represents a hydrocarbon group. From the viewpoint of easy handling, Rb is preferably an alkyl group, alkenyl group, alkyl-substituted or alkenyl-substituted phenyl group having 1 to 40 carbon atoms, or alkyl-substituted or alkenyl-substituted. Naphthyl group.
The alkyl group and alkenyl group may be linear, branched, or cyclic.

Furthermore, the organic compound of the lanthanum series metal element includes an amine compound of the lanthanum series metal element.
Examples of the amine compound of the lanthanum series metal element include, but are not limited to, compounds represented by the formula Ln (NRc ₂ ) ₃ .
Here, Rc represents a hydrocarbon group, and from the viewpoint of ease of handling, preferably an alkyl group, alkenyl group, alkyl-substituted or alkenyl-substituted phenyl group, or alkyl-substituted or alkenyl-substituted group having 1 to 40 carbon atoms. Naphthyl group. The alkyl group and alkenyl group may be linear, branched, or cyclic.

In addition, examples of the organic compound of the lanthanum series metal element include carboxylic acid compounds of the lanthanum series metal element.
Examples of the carboxylic acid compound of the lanthanum series metal element include, but are not limited to, compounds represented by the formula Ln (OCORd) ₃ .
Here, Rd represents a hydrocarbon group. From the viewpoint of easy handling, Rd is preferably an alkyl group, alkenyl group, alkyl-substituted or alkenyl-substituted phenyl group, or alkyl-substituted or alkenyl-substituted naphthyl group in the range of 1 to 40. It is.
The alkyl group and alkenyl group may be linear, branched, or cyclic.
The carboxyl group may be any of primary, secondary and tertiary bonds to the hydrocarbon.
Preferred carboxylic acids include, but are not limited to, octanoic acid, 2-ethyl-hexanoic acid, oleic acid, stearic acid, isostearic acid (2- (1,3,3-trimethylbutyl)- 5,7,7-trimethyloctanoic acid), benzoic acid, naphthenic acid, versatic acid mainly having 10 carbon atoms (commercially available product, for example, trade name “Versatic acid 10” manufactured by Shell Chemical Co., Ltd.) .
A carboxylic acid having a branch at the α-position is preferable from the viewpoint of solubility, and specific examples include 2-ethyl-hexanoic acid, isostearic acid, 2-isopropyl-5-methylhexanoic acid, and versatic acid.

Furthermore, examples of the organic compound of a lanthanum series metal element include an organophosphate compound of a lanthanum series metal element.
Examples of the organic phosphate compound of a lanthanum series metal element include a compound represented by the formula Ln (OPORERf) ₃ .
Here, Re and Rf each independently represent a hydrocarbon group, and from the viewpoint of ease of handling, preferably an alkyl group, alkenyl group, alkyl-substituted or alkenyl-substituted phenyl group or alkyl group in the range of 1 to 40 A substituted or alkenyl-substituted naphthyl group;
The alkyl group or alkenyl group may be linear, branched or cyclic.
From the viewpoint of polymerization activity, specific examples of preferred organic phosphate compounds include tris (di-2-ethylhexyl phosphate) and tris (dinonylphenyl phosphate).

Furthermore, the organic compound of a lanthanum series metal element includes an organic phosphorous acid compound of a lanthanum series metal element.
Examples of organic phosphite compounds of lanthanum series metal elements include, but are not limited to, compounds represented by the formula Ln (OPRgRh) ₃ .
Here, Rg and Rh each independently represent a hydrocarbon group, and from the viewpoint of easy handling, preferably an alkyl group having 1 to 40 carbon atoms, an alkenyl group, an alkyl-substituted or alkenyl-substituted phenyl group, or an alkyl group. Or it is an alkenyl substituted naphthyl group.
The alkyl group or alkenyl group may be linear, branched, or cyclic. Specific examples of preferable organic phosphite compounds from the viewpoint of polymerization activity include tris (di-2-ethylhexyl phosphite) and tris (dinonylphenyl phosphite).

Among the organic compounds of the various lanthanum series metal elements described above, from the viewpoint of solubility in an organic solvent, a carboxylic acid compound, an organic phosphoric acid compound, and a lanthanoid-aluminum crosslinked complex are preferable, and a carboxylic acid compound and a lanthanoid-aluminium are preferable. A cross-linked complex is more preferred.
In addition, the organic compound of the lanthanum series metal element may be a composite salt of two or more of the above-described compounds, for example, a composite salt of the above-described carboxylic acid compound and an organic phosphoric acid compound.

The (b) organoaluminum compound used in the polymerization step is an organoaluminum compound other than (a) a heavy metal compound capable of coordination polymerization, such as a lanthanoid-aluminum crosslinked complex and an aluminum halide.
The (b) an organoaluminum compound is not particularly limited, from the viewpoint of polymerization activity, include compounds represented by _{AlRi (3-m) H m} .
Here, Ri is an aliphatic hydrocarbon group or alicyclic hydrocarbon group having 1 to 20 carbon atoms, preferably 2 to 8 carbon atoms; or 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, An alkyl-substituted or alkenyl-substituted aromatic hydrocarbon group is represented.
m is 0, 1 or 2, preferably 0 or 1, and H represents a hydrogen atom.
The organoaluminum compound may be an alumoxane compound (a compound having a direct bond between carbon and aluminum and also having a direct bond between oxygen and aluminum).

(B) The organoaluminum compound is not limited to the following. For example, trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum, tricyclohexylaluminum, diethylaluminum dihydride, diisobutylaluminum Hydride, ethylaluminum dihydride, isobutylaluminum dihydride, methylalumoxane, ethylalumoxane, isobutylalumoxane, butylalumoxane, hexylalumoxane, octylalumoxane, etc. are preferred, triethylaluminum, triisobutylaluminum, diethylaluminum hydride, Diisobutylaluminum hydride, methylalumoxy Down, ethyl alumoxane, butyl alumoxane, isobutyl alumoxane, t- butyl alumoxane, hexyl alumoxane, octyl alumoxane is more preferable.
These may be used alone or in combination of two or more.

  Examples of the halogen-containing Lewis acid compound (c) used in the polymerization step include halogen compounds of elements belonging to Group IIIb, IVb or Vb of the periodic table. From the viewpoint of polymerization activity, aluminum halide is preferable. And organometallic halides.

The halogen element of the aluminum halide is preferably chlorine or bromine from the viewpoint of polymerization activity.
Examples of aluminum halides include, but are not limited to, methyl aluminum dibromide, methyl aluminum dichloride, ethyl aluminum dibromide, ethyl aluminum dichloride, butyl aluminum dibromide, butyl aluminum dichloride, dimethyl aluminum bromide, Examples include dimethylaluminum chloride, diethylaluminum bromide, diethylaluminum chloride, dibutylaluminum bromide, dibutylaluminum chloride, methylaluminum sesquibromide, methylaluminum sesquichloride, ethylaluminum sesquibromide, ethylaluminum sesquichloride, and aluminum tribromide.

  Examples of organometallic halides include, but are not limited to, dibutyltin dichloride, antimony trichloride, antimony pentachloride, phosphorus trichloride, phosphorus pentachloride and tin tetrachloride.

  Among these, aluminum halides are preferable from the viewpoint of availability, and among them, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum bromide, ethylaluminum sesquibromide, and ethylaluminum dibromide are more preferable. preferable.

The amount and composition ratio of each component of the composite catalyst used in the polymerization step of step (1) are not particularly limited and can be appropriately selected depending on the purpose.
The amount of component (a) to be used is usually 0.005 to 2.5 mmol, preferably 0.025 to 0.5 mmol, relative to 1 mol of the conjugated diene monomer. The usage-amount of the component (b) with respect to 1 mol of conjugated diene type monomers is 0.05-25 mmol normally, Preferably it is the range of 0.25-5 mmol. The amount of the component (c) used per mole of the conjugated diene monomer is different depending on the number of halogen atoms contained in the molecule, and is represented by the number of halogen atoms relative to 1 mole of the lanthanum series metal element (Ln). Halogen atom / Ln = 1 to 6, preferably 1.5 to 3.

  In this embodiment, from the viewpoint of producing a conjugated diene monomer having a high 1,4-cis content, the coordination polymerization initiator preferably contains an organic compound of a lanthanum series metal element.

<Monomer>
The conjugated diene monomer used in (Step 1) is not limited to the following, and examples thereof include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3- Examples thereof include conjugated diene compounds having 4 to 8 carbon atoms such as pentadiene (piperylene) and 2,3-dimethyl-1,3-butadiene, or mixtures thereof.
Among these, butadiene is preferable from the viewpoint of polymerization activity and usefulness of the resulting polymer.

In (Step 1), the conjugated diene monomer may be copolymerized with other monomers to obtain a conjugated diene copolymer.
Examples of other monomers copolymerizable with the conjugated diene monomer include, but are not limited to, vinyl aromatics such as styrene, α-methylstyrene, p-methylstyrene, and vinylethylbenzene. Monomers; (meth) acrylic monomers such as methyl (meth) acrylate and butyl (meth) acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile.
The blending ratio of the conjugated diene monomer and the other monomer is not particularly limited, but from the viewpoint of the usefulness of the resulting conjugated diene polymer, the conjugated diene monomer is 50 to 100% by mass. More preferably, it is 70-100 mass%, More preferably, it is 90-100 mass%.

<Impurities in monomer>
In general, the conjugated diene monomer may contain impurities such as acetylenes, allenes, and aldehydes.
Examples of acetylenes include 1-butyne and vinyl acetylene, and examples of allenes include propadiene and 1,2-butadiene. Therefore, it is preferable to perform a step (purification step) of purifying the conjugated diene monomer before performing the polymerization reaction using the conjugated diene monomer.
In the purification step, the total amount of acetylenes and allenes contained as impurities in the conjugated diene monomer is preferably 50 ppm or less, and more preferably 20 ppm or less.
The purification method is not particularly limited, and for example, methods such as hydrogenation and distillation can be employed. Such a purification step further increases the activity of the polymer terminal and further increases the yield of the modification reaction.

<Solvent>
The polymerization in (Step (1)) is usually carried out by bulk polymerization or solution polymerization.
The polymerization solvent that can be used when the solution polymerization method is used is not limited to the following. For example, n-butane, isobutane, n-pentane, n-hexane, 2-methylpentane (isohexane), n- A linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon having a boiling point of 200 ° C. or lower, such as heptane, cyclohexane, methylcyclopentane, benzene, and toluene, is preferable.
A polymerization solvent may be used individually by 1 type, and may use 2 or more types together.
Furthermore, a mixed solvent containing a halogenated hydrocarbon such as methylene chloride or chlorobenzene, an aprotic polar organic solvent such as a ketone compound, an ether compound or a trialkylamine compound can be used, and the catalyst used By appropriately selecting the solvent according to the above, the solubility of the composite catalyst in the polymerization solvent and the polymerization activity can be further improved.

<Polymerization conditions, temperature>
The polymerization temperature in (Step (1)) is not particularly limited, and is usually −30 to 150 ° C., preferably 10 to 120 ° C., more preferably 20 to 80 ° C., and further preferably 30 to 30 ° C. 60 ° C.
As the polymerization temperature increases, the polymerization rate and polymerization rate increase, and the microstructure of the resulting conjugated diene polymer tends to increase the amount of vinyl bonds. On the other hand, when the polymerization temperature is lowered, the proportion of 1,4-cis bonds tends to increase, and a polymer having many 1,4-cis bonds can be obtained.

The polymerization reaction mode is not particularly limited, and either a batch method or a continuous method can be used.
Prior to the polymerization, a part of the catalyst components may be combined or the whole may be subjected to a preliminary reaction or aging reaction in the presence or absence of the conjugated diene monomer.
The aging conditions include (a) a heavy metal compound capable of coordination polymerization, (b) an organoaluminum compound, and (c) in an inert solvent in the presence or absence of the conjugated diene monomer to be polymerized. ) Mix components of the halogen-containing Lewis acid compound. The aging temperature is -50 to 80 ° C, preferably -10 to 50 ° C, and the aging time is 0.01 to 24 hours, preferably 0.05 to 5 hours, particularly preferably 0.1 to 1 hour.

<Microstructure>
In the polymerization step of (Step (1)), a conjugated diene polymer mainly composed of 1,4-cis bonds and few vinyl bonds (that is, 1,2-bonds and 3,4-bonds) is obtained.
Here, “mainly consisting of 1,4-cis bonds” means that the proportion of 1,4-cis content in the conjugated diene polymer is 80 mol% or more, preferably 90 mol% or more, More preferably, it is 95 mol% or more. That is, the microstructure of the conjugated diene polymer obtained preferably has a 1,4-cis content of 90 mol% or more and a vinyl bond content of 10 mol% or less.
The microstructure can be controlled by adjusting conditions such as the composition of the polymerization initiator and the polymerization temperature. In particular, when a polymerization initiator containing neodymium is used, the ratio of cis bonds among 1,4-bonds tends to increase. Therefore, when a polymerization initiator containing neodymium is used, the resulting conjugated diene polymer The 1,4-cis content is preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 98 mol% or more.
The microstructure of the conjugated diene polymer can be measured using an infrared spectrophotometer described in Examples described later, and the 1,4-cis content can be calculated using the Morello method.

(Process (2))
In the step (2), the conjugated diene polymer obtained in the above (step (1)) is reacted with the compound A having four or more alkoxy groups bonded to a silyl group, a tertiary amino group, and an ester group. A modification step is carried out to obtain a modified conjugated diene polymer.

The reaction of the conjugated diene polymer and the compound A is carried out by mixing the conjugated diene polymer and the compound A after achieving a predetermined polymerization rate.
The predetermined polymerization rate can be appropriately set according to the physical properties of the target modified conjugated diene polymer, preferably 90% or more, more preferably 95% or more, and after reaching the polymerization rate It is preferable to react with compound A.
By reacting under such conditions, a uniform modified conjugated diene polymer having a narrow molecular weight distribution tends to be obtained.
If necessary, the compound A can be divided or continuously added at a polymerization rate of 30 to 90% for reaction. In that case, a modified conjugated diene polymer having a wide molecular weight distribution and a high modification rate tends to be obtained.

Compound A used as a modifier in (Step (2)) has a compound structure containing 4 or more alkoxy groups bonded to a silyl group, a tertiary amino group, and an ester group. It has an ester group that is highly reactive with the polymerization active terminal of the polymer.
By having this ester group, the compound A and the active end of the conjugated diene polymer are more easily bonded to each other than the conventionally used modifiers. It is possible to obtain a modified conjugated diene polymer in which an alkoxy group bonded to a high silyl group is introduced at a high modification rate.
Furthermore, since it has 4 or more alkoxy groups bonded to silyl groups and has a tertiary amino group, the modified conjugated diene polymer obtained by the production method of the present embodiment and a silica inorganic filler When the modified conjugated diene polymer composition is used as a raw material rubber for tires, it becomes excellent in filler dispersibility, fuel economy and wear resistance.
In compound A, the number of alkoxy groups bonded to the silyl group is preferably 5 or more, and more preferably 6 or more.
Preferable compound A includes a compound represented by the following formula (1).
By using the compound represented by the following formula (1) as a modifier, it can efficiently react with the active terminal of the conjugated diene polymer. As a result, the functional group can be efficiently introduced into the terminal of the conjugated diene polymer, and the modification rate can be increased.

・・・（１）

... (1)

In the formula (1), R ¹ to R ⁵ represents an alkyl group, or an aryl group having 6 to 20 carbon atoms C 1 -C 20 each independently, R ⁶ to R ⁸ is 1 to 20 carbon atoms Represents an alkylene group, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, and the sum of m and r is 4 or more.

The compound represented by the formula (1) is not limited to the following, but examples thereof include N- (methoxycarbonylmethyl) -N, N-bis (3-trimethoxysilylpropyl) amine, N- (Methoxycarbonylmethyl) -N, N-bis (3-triethoxysilylsilylpropyl) amine, N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine, N- (ethoxycarbonyl) Ethyl) -N, N-bis (3-triethoxysilylpropyl) amine, N- (methoxycarbonylpropyl) -N, N-bis (3-trimethoxysilylpropyl) amine, N- (ethoxycarbonylpropyl) -N N-bis (3-triethoxysilylpropyl) amine, N- (methoxycarbonylethyl) -N, N-bis (3-to Methoxysilylbutyl) amine, N- (ethoxycarbonylethyl) -N, N-bis (3-triethoxysilylbutyl) amine, N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpentyl) Amine, N- (ethoxycarbonylethyl) -N, N-bis (3-triethoxysilylpentyl) amine, N- (methoxycarbonylpropyl) -N, N-bis (3-trimethoxysilylbutyl) amine, N- (Ethoxycarbonylpropyl) -N, N-bis (3-triethoxysilylbutyl) amine, N- (methoxycarbonylpropyl) -N, N-bis (3-trimethoxysilylpentyl) amine, N- (ethoxycarbonylpropyl) ) -N, N-bis (3-triethoxysilylpentyl) amine and the like.
Among these, N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine and N- (ethoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine By using the modified conjugated diene polymer modified, the modification reaction proceeds well and there are six alkoxymethyl groups equivalent to the tertiary nitrogen atom. The interaction with carbon is further enhanced, which is preferable.

  Although the usage-amount of the compound A is not specifically limited, it is 0.5-18mo1 with respect to 1mo1 active terminal of a conjugated diene polymer from a viewpoint of the modification | denaturation rate increase of the modified conjugated diene polymer obtained. Although it is preferable, the amount of the modifier added can be appropriately adjusted according to the desired modification ratio.

Compound A may be added alone or as a solution dissolved in an inert hydrocarbon or the like.
Compound A may be added all at once, or may be added in portions or continuously.
The modification reaction is usually performed at the polymerization temperature within the same temperature range as the above polymerization temperature, and the temperature difference from the polymerization reaction is preferably within 10 ° C., and is performed for several minutes to several hours. . The reaction time is preferably 5 minutes to 3 hours.

The modified conjugated diene polymer obtained by the production method of the present embodiment has a high modification rate.
The modification rate referred to here is, as described in [Examples] described later, by utilizing the property that the modified polymer adsorbs on a gel permeation chromatography (GPC) column using a silica gel as a filler. It can be measured by comparison with GPC using a system gel as a filler.
The modification rate of the modified conjugated diene polymer obtained by the production method of the present embodiment is not particularly limited and can be appropriately adjusted according to desired physical properties, but is preferably 30% or more, more preferably 40%. Above, more preferably 50% or more, still more preferably 60% or more.

(Oil Exhibition)
In the production method of the present embodiment, after the steps (1) and (2) described above, if the polymerization step is performed by solution polymerization, a process oil is added as necessary before the desolvation step. Alternatively, an oil-extended modified conjugated diene polymer may be used.
The process oil is not limited to the following, but from the viewpoint of compatibility, aroma oil, naphthenic oil, paraffin oil, aroma substitute oil having a polycyclic aromatic component of 3% by mass or less by the IP346 method, etc. Is preferred. Among these, it is preferable to use an aroma substitute oil having a polycyclic aromatic component of 3% by mass or less from the viewpoint of environmental safety, prevention of oil bleed, and wet grip characteristics.
Examples of the aroma replacement oil include, but are not limited to, for example, Treated Distilled Aromatic Extract (TDAE), Mildly or Medium E, etc. of Kautschuk Gummi Kunststoff 52 (12) 799 (1999). Other examples include Residual Aromatic Extract (RAE) and Safety or Special Residual Aromatic Extract (SRAE).
The amount of these process oils used is not particularly limited, and is usually 10 to 60 parts by mass with respect to 100 parts by mass of the modified conjugated diene polymer. From the viewpoint of oil bleed prevention and workability of the product, 20 It is preferably ˜37.5 parts by mass.

(Finishing)
In the production method of the modified conjugated diene polymer of this embodiment, a polymerization terminator and a stabilizer are added to the reaction system as necessary, and a known desolvation method and drying operation used in the production of the conjugated diene polymer are carried out. By doing so, the modified conjugated diene polymer can be recovered. For example, solvent removal by steam stripping, compressed water squeezing machine such as screw extruder type squeeze dehydrator, expander dehydrator, desolvation method using hot air dryer, drying operation, concentration method in flushing tank, vent By carrying out a method of devolatilization with an extruder or the like, a method of devolatilization directly with a drum dryer or the like, the target modified conjugated diene polymer can be recovered.
The polymerization terminator can be selected from water or a protic polar organic compound.
Examples of the protic polar organic compound include, but are not limited to, various alcohols, phenols, and carboxylic acid compounds.
The stabilizer can be selected from known conjugated diene polymer stabilizers and antioxidants.
Examples of these particularly preferred stabilizers are 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) Examples include propionate, 2,4-bis (n-octylthiomethyl) -6-methylphenol, N, N′-dialkyldiphenylamine, and N-alkyldiphenylamine.
Although it does not specifically limit as a form of the modified conjugated diene type polymer obtained, A bale etc. are mentioned.

[Modified Conjugated Diene Polymer]
(Construction)
In this embodiment, the target modified conjugated diene polymer can be obtained through the steps (1) and (2).
Examples of the modified conjugated diene polymer of the present embodiment include modified conjugated diene polymers represented by the following formula (2) or formula (3).

・・・（２）

... (2)

In the formula (2), P is a conjugated diene polymer having a 1,4-cis content of 80 mol% or more, and R ^{2 to} R ⁵ are each independently an alkyl group having 1 to 20 carbon atoms or R ^{6 to} R ⁸ represent an alkylene group having 1 to 20 carbon atoms, n is an integer of 1 to 3, m is an integer of 1 to 3, Is an integer of 1 to 3, and the sum of m and r is 4 or more.

・・・（３）

... (3)

In the formula (3), P is a conjugated diene polymer having a 1,4-cis content of 80 mol% or more, and R ^{2 to} R ⁵ are each independently an alkyl group having 1 to 20 carbon atoms or R ^{6 to} R ⁸ represent an alkylene group having 1 to 20 carbon atoms, n is an integer of 1 to 3, m is an integer of 1 to 3, Is an integer of 1 to 3, and the sum of m and r is 4 or more.

Among formulas (2) and (3), R ² is a methyl group or an ethyl group, n is an integer of 1, m is preferably an integer of 2 to 3, and r is 2 to 3. It is preferably an integer.

(Molecular weight)
The number average molecular weight of the modified conjugated diene polymer of the present embodiment is not particularly limited, but is preferably 100,000 to 700,000 from the viewpoint of balance between fuel efficiency and wear resistance, More preferably, it is 10,000 to 600,000, and more preferably 200,000 to 400,000.
The weight average molecular weight of the modified conjugated diene polymer of the present embodiment is not particularly limited, but is preferably 200,000 to 800,000 from the viewpoint of the balance between wear resistance and workability, and 300,000. More preferably, it is -700,000, and it is further more preferable that it is 40-60.
In addition, the molecular weight distribution of the modified conjugated diene polymer of the present embodiment is not particularly limited, but is 1.5 to 3.5 from the viewpoint of a balance between fuel saving performance, wearability, and workability. It is preferable that it is preferably 1.7 to 2.5, and more preferably 1.8 to 2.5.
A number average molecular weight, a weight average molecular weight, and molecular weight distribution can be measured by the method as described in the Example mentioned later.

[Modified Conjugated Diene Polymer Composition]
The modified conjugated diene polymer composition of the present embodiment includes 100 parts by mass of a rubber component containing 10 parts by mass or more of the modified conjugated diene polymer of the above-described embodiment, and 0.5 to 300 silica-based inorganic fillers. Part by mass.
The modified conjugated diene polymer of this embodiment is generally processed by a method usually used in the rubber industry and used as a rubber product.
In 100 parts by mass of the rubber component, the content of the modified conjugated diene polymer of the present embodiment is preferably 10 parts by mass or more, more preferably 20 parts by mass or more from the viewpoint of improvement in fuel saving performance and improvement in wear resistance. More preferred is 30 parts by mass or more.
In general, a conjugated diene polymer is superior in tensile strength to a random copolymer of styrene-butadiene (SBR), and even if the content of the modified conjugated diene polymer is 10 parts by mass or more, the tensile properties and resistance of SBR are improved. Although there is an effect to reinforce the wearability, when it is not a modified conjugated diene polymer, it is accompanied by a reduction in fuel saving performance. That is, if it is a modified conjugated diene polymer, it is possible to reinforce tensile properties and wear resistance without impairing fuel efficiency.

The modified conjugated diene-based polymer composition of the present embodiment is blended not only with a silica-based inorganic filler, but also with other rubber materials as necessary, and further, a silane coupling agent, a rubber softener, a vulcanizing agent, Vulcanization aids and other additives can be added for processing.
In blending, various mechanical mixers such as a Banbury mixer and a roll mill are used. The modified conjugated diene polymer of the present embodiment has the advantages that the torque at the time of blending is small and the filler is well dispersed even if the kneading time is short. Further, the tack of the blended fabric is excellent and suitable for processing rubber products.

(Other rubber materials)
Examples of the other rubber material include, but are not limited to, natural rubber and synthetic rubber.
Examples of the synthetic rubber include, but are not limited to, for example, low cis polybutadiene, vinyl cis butadiene rubber (VCR), styrene butadiene rubber (SBR), isoprene rubber, butyl rubber, ethylene propylene diene rubber (EPDM). ) And the like.

  The addition amount of the other rubber material is not particularly limited, but is 0 to 900 parts by mass with respect to 100 parts by mass of the modified conjugated diene polymer depending on the required performance of the resulting modified conjugated diene polymer composition. It is preferably 10 to 400 parts by mass, and more preferably 50 to 300 parts by mass.

(Silica-based inorganic filler)
As the silica-based inorganic filler used in the modified conjugated diene-based polymer composition of the present embodiment, solid particles having SiO ₂ or Si ₃ Al as a main component of a structural unit can be used.
The main component means a component having the largest content among substances constituting the silica-based inorganic filler. Examples of the silica-based inorganic filler include, but are not limited to, inorganic fibrous materials such as silica, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, and glass fiber. .
Further, 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, and silica is more preferable.

  As silica, dry silica, wet silica, synthetic silicate silica, and the like can be used. Among them, wet silica is most preferable because it has the most remarkable effect of improving fracture characteristics and wet skid resistance.

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

Moreover, the compounding quantity of the silica type inorganic filler of the modified conjugated diene polymer composition of this embodiment is 0.5-300 with respect to 100 mass parts of rubber components containing the modified conjugated diene polymer of this embodiment. It is a mass part, 5-200 mass parts is preferable, and 20-100 mass parts is more preferable.
By adding the silica-based inorganic filler in an amount of 0.5 parts by mass or more, the effect of addition can be effectively expressed, and by setting it to 300 parts by mass or less, the deterioration of dispersibility does not occur, and the modified conjugated diene of this embodiment Good processability and high mechanical strength can be obtained in the polymer composition.

(Carbon black)
The modified conjugated diene polymer composition of this embodiment may contain carbon black as a reinforcing filler other than the silica inorganic filler described above.
As the carbon black, carbon black of each class such as SRF, FEF, HAF, ISAF, SAF can be used, and carbon black having a nitrogen adsorption specific surface area of 50 m ² / g or more and a DBP (dibutyl phthalate) oil absorption of 80 mL / 100 g is preferable. .

The content of carbon black is preferably 0.5 to 100 parts by mass, more preferably 3 to 100 parts by mass with respect to 100 parts by mass of the rubber component containing 10 parts by mass or more of the modified conjugated diene polymer of the present embodiment. 5 to 50 parts by mass is more preferable.
In order to express the performance required for uses such as tires such as dry grip performance and conductivity, it is preferable to add 0.5 parts by mass or more with respect to 100 parts by mass of the rubber component, and 100 parts by mass from the viewpoint of dispersibility. Part or less.

(Metal oxide, metal hydroxide)
In addition to the silica-based inorganic filler and carbon black described above, the modified conjugated diene-based polymer composition of the present embodiment may further include a metal oxide or a metal hydroxide as a reinforcing filler. Good.

  Metal oxide refers to solid particles having the chemical formula MxOy (M is a metal atom, x and y are each an integer of 1 to 6) as a main component of a structural unit, and is not limited to the following. For example, alumina, titanium oxide, 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.

  Examples of the metal hydroxide include, but are not limited to, aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide.

The reinforcing filler described above can be arbitrarily selected according to the required performance.
Moreover, these may be used individually by 1 type, and may mix and use 2 or more types as needed.

  The compounding amount of the metal oxide and / or metal hydroxide is 10 parts by mass or more of the modified conjugated diene polymer of the present embodiment from the viewpoint of processability and the performance of the resulting modified conjugated diene copolymer composition. 0.5-100 mass parts is preferable with respect to 100 mass parts of rubber components to contain, 3-100 mass parts is more preferable, and 5-50 mass parts is further more preferable.

(Silane coupling agent)
The modified conjugated diene polymer composition of this embodiment may contain a silane coupling agent.
The silane coupling agent has a function of tightly interacting the above-described rubber component and silica-based inorganic filler, and has an affinity or binding property to each of the rubber component and the silica-based inorganic filler. It is.
As the silane coupling agent, generally, a compound having a sulfur bond portion and an alkoxysilyl group portion in one molecule is preferably used.

  Examples of the silane coupling agent include, but are not limited to, bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl]- And disulfide, bis- [2- (triethoxysilyl) -ethyl] -tetrasulfide, and the like.

  Although the addition amount of a silane coupling agent is not limited to the following, it is 0.1-10 mass parts with respect to 100 mass parts of silica type inorganic fillers from an effect and economical viewpoint. Preferably, it is 0.5-5 mass parts.

(Rubber softener)
The modified conjugated diene polymer composition of this embodiment may contain a rubber softener.
As the rubber softener, mineral oil or liquid or low molecular weight synthetic or vegetable softener is preferably used.
The type of rubber softener is not particularly limited, but from the viewpoint of compatibility and environmental safety, aroma oil, naphthenic oil, paraffin oil, aroma substitute oil containing 3% by mass or less of polycyclic aromatic component by IP346 method Etc.

  The addition amount of the rubber softening agent is not particularly limited, but from the viewpoint of effect and economy, it is 5 to 150 with respect to 100 parts by mass of the rubber component containing 10 parts by mass or more of the modified conjugated diene polymer of the present embodiment. It is preferable that it is a mass part, and it is more preferable that it is 5-100 mass parts.

(Vulcanizing agent, etc.)
The modified conjugated diene polymer composition of the present embodiment may be a vulcanized product containing a vulcanizing agent.
As the vulcanizing agent, radical initiators, sulfur, sulfur compounds and the like are used.
Examples of the radical initiator include peroxides such as peroxyketals and dialkyl peroxides.
Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur.
Examples of the sulfur compound include sulfur monochloride, sulfur dichloride, and organic polysulfide.

Furthermore, a vulcanization auxiliary and a vulcanization accelerator can be used together as necessary.
As the vulcanization aid, zinc white, stearic acid or the like is used.
As the vulcanization accelerator, various known vulcanization accelerators are used. Guanidine vulcanization accelerators, thiourea vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators, sulfenamides A system vulcanization accelerator or the like is used.

(Other additives)
As other additives, for example, anti-aging agents, waxes, conductive agents, colorants and the like are used.
Examples of the anti-aging agent include p-phenylenediamine, naphthylamine, diphenylamine, quinoline, and phenol.
Examples of the wax include paraffinic petroleum wax.
Examples of the conductive agent include metal powder, graphite, carbon fiber, and the like.
Examples of the colorant include pigments and dyes.

〔Rubber product〕
The modified conjugated diene polymer of this embodiment is blended with the above-described components as necessary to obtain a modified conjugated diene polymer composition, and vulcanized for use in the production of various rubber products.
In particular, it is optimally used as a raw material rubber for tires, and preferably a tire containing the modified conjugated diene polymer of this embodiment.
For example, when used for sidewalls, it has excellent resistance to bending cracks and low heat generation.When used for treads, it has excellent fuel economy and wear resistance, flexibility at low temperatures, and when used for carcass. Since it is excellent in low exothermic property and bending crack resistance, both are preferably used.
As other uses, it is also suitably used as a material for various industrial articles and shoe soles.

Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited to these examples.
The analysis method was performed by the following method.

(1) 1,4-cis content 1,4-cis content is determined by using the following polymers A to G, [(1,4-cis bond amount) / (unsaturated bond amount)] An external spectrophotometer (Fourier transform infrared spectrophotometer (FT / IR-4100) manufactured by JASCO Corporation) was used for measurement, and data processing was performed by the Morero method.

(2) Mooney Viscosity According to JIS K6300-1, using an L-shaped rotor, preheating was performed for 1 minute, and the viscosity after 4 minutes was measured. The measurement temperature was 100 ° C.

(3) Number average molecular weight, weight average molecular weight, molecular weight distribution Chromatogram was measured using gel permeation chromatography (GPC) used by connecting three columns with polystyrene gel as a filler, and standard polystyrene was measured. From the relationship between the retention capacity and molecular weight obtained from the calibration curve used, the frequency for all peak areas in each molecular weight range is calculated according to the conventional method, and the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution are calculated. did.
Tetrahydrofuran (THF) was used as the eluent.
The column is a guard column; manufactured by Tosoh Corporation, “TSK guard column HHR-H”, the column: manufactured by Tosoh Corporation “TSK-Super H 7000”, “TSK-Super H 6000”, “TSK-Super H 5000”, oven temperature : 40 ° C., THF flow rate 0.6 mL / min, manufactured by Tosoh Corporation: HLC-8020, detector; RI was used.
A sample for measurement was measured by injecting 20 μL using 10 mg dissolved in 20 mL of THF.

(4) Modification rate Applying the property that the modified component is adsorbed on a GPC column using silica gel as a filler, using a sample solution containing a sample and a low molecular weight internal standard polystyrene molecular weight of 5000 (polystyrene does not adsorb), GPC (manufactured by Tosoh Corporation: HLC-8020) and a silica-based column (guard column; “DIOL” 4.6 × 12.5 mm 5 micron, column) used in (3) above. GPC (Tosoh Corporation: “CCP8020” series build-up type GPC system) of “Zorbax PSM-1000S”, “PSM-300S”, “PSM-60S”, oven temperature: 40 ° C., THF flow rate 0.5 mL / min) "AS-8020", "SD-8022", "CCPS", "CO-8020", "RI-" Both chromatograms of 8021 ") were measured, the amount of adsorption to the silica column was measured from the difference between them based on the internal standard polystyrene peak, and the coupling reaction rate was determined.
As a sample for measurement, in common, 10 mg of a measurement object was dissolved in 20 mL of THF together with 5 mg of standard polystyrene, and 200 μL was injected for measurement.
Specifically, the total peak area of the chromatogram using the polystyrene column is 100, the peak area of the sample polystyrene is P1, the peak area of the standard polystyrene is P2, and the peak area of the chromatogram using the silica column is The total was 100, the sample peak area was P3, the peak area of standard polystyrene was P4, and the modification rate was calculated by the following formula.
Denaturation rate (%) = [1- (P2 × P3) / (P1 × P4)] × 100

[Example 1]
The inside of the fully dried 300 mL pressure-resistant mini cylinder was sufficiently replaced with dry nitrogen.
There, 130 mL of a 20% by mass cyclohexane solution containing 20 g of 1,3-butadiene, and isostearic acid (manufactured by Wako Pure Chemical Industries, Ltd., 2- (1,3,3-trimethylbutyl) -5,7,7 -Trimethyloctanoic acid) sodium salt and neodymium chloride were reacted with 11.7 mL of a 30% by mass cyclohexane solution containing 2.7 mmol of neodymium isostearate, and shaken at room temperature for 5 minutes.
Subsequently, 22.5 mL of a 1 molar hexane solution containing 22.5 mmol of diisobutylaluminum hydride was further added and shaken, and then allowed to stand for 5 minutes.
After adding 8.1 mL of 1 molar hexane solution of ethylaluminum sesquichloride and shaking so that Cl / Nd (molar ratio) = 2, the coordination polymerization initiator solution was obtained by allowing to stand for 20 minutes. Prepared.
Next, the inside of the pressure-resistant autoclave with a stirrer having an inner volume of 11 L that was sufficiently dried was sufficiently replaced with dry nitrogen.
Thereto, 6 kg of a cyclohexane mixed solution containing 900 g of 1,3-butadiene was charged into an autoclave, 170 mL of a coordination polymerization initiator solution prepared in advance was added, and polymerization was carried out at 50 ° C. for 2 hours.
After the polymerization reaction, 3.8 mmol of N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine was added as a modifier and reacted at 50 ° C. for 1 hour.
Thereafter, 100 mL of a methanol / siloxane solution (30/70) containing 5 g of 2,6-bis (tert-butyl) -4-methylphenol was added to stop the reaction.
The solvent was removed using a drum dryer to obtain a polymer A.
Table 1 shows the analysis results of the obtained polymer A.

[Example 2]
In a glove box, 0.04 g (0.11 mmol) of lanthanoid-aluminum cross-linked complex Nd [(μ-Me ₂ ) AlMw ₂ ] ₃ (manufactured by Nichia Corporation) is weighed and dissolved in 20 mL of cyclohexane in a sample bottle. It was.
4.6 mL (5.4 mmol) of methylaluminoxane (manufactured by Tosoh Finechem Co., Ltd., TMAO-211 1.6M) was added and stirred for 30 minutes.
1.26 mL (1.3 mmol) of diisobutylaluminum hydride (Kanto Chemical Co., 1.0 M, hexane solution) was added and stirred for 10 minutes.
Thereafter, 0.13 mL (0.22 mmol) of diethylaluminum chloride (manufactured by Tosoh Finechem Co., Ltd., 1.6 M, hexane solution) was added and allowed to stand for 15 minutes to prepare a coordination polymerization initiator solution.
Next, the inside of the fully dried pressure-resistant autoclave with a stirrer having an internal volume of 5 L was sufficiently substituted with dry nitrogen. Then, 2.4 kg of a cyclohexane mixed solution containing 210 g of 1,3-butadiene was charged into the autoclave, and the total amount of the initiator solution prepared in advance was added, and polymerization was carried out at 50 ° C. for 1 hour.
After the polymerization reaction, 1.3 mmol of N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine was added as a modifier and reacted at 50 ° C. for 2 hours.
Thereafter, 30 mL of a methanol / siloxane solution (30/70) containing 5 g of 2,6-bis (tert-butyl) -4-methylphenol was added to stop the reaction.
The solvent was removed using a drum dryer to obtain a polymer B.
Table 1 shows the analysis results of the obtained polymer B.

Example 3
The addition amount of N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine, which is a modifier, was changed to 0.6 mmol. Other conditions were obtained in the same manner as in [Example 2] to obtain a polymer C.
Table 1 shows the analysis results of the obtained polymer C.

Example 4
In a glove box, 0.33 mmol of cobalt octate was weighed and dissolved in 20 mL of cyclohexane in a sample bottle.
20.2 mL of methylaluminoxane (manufactured by Tosoh Finechem Corporation, TMAO-211 1.6M) was added and stirred for 30 minutes.
A coordination polymerization initiator solution was prepared by adding 1.26 mL (1.3 mmol) of diisobutylaluminum hydride (Kanto Chemical, 1.0 M, hexane solution) and stirring for 10 minutes.
Next, the inside of the fully dried pressure-resistant autoclave with a stirrer having an internal volume of 5 L was sufficiently substituted with dry nitrogen.
Then, 2.4 kg of a cyclohexane mixed solution containing 210 g of 1,3-butadiene was charged into the autoclave, the whole amount of the coordination polymerization initiator solution prepared in advance was added, and polymerization was carried out at 50 ° C. for 1 hour.
After the polymerization reaction, 1.3 mmol of N- (methoxycarbonylethyl) -N, N-bis (3-trimethoxysilylpropyl) amine was added as a modifier and reacted at 50 ° C. for 2 hours.
Thereafter, 30 mL of a methanol / siloxane solution (30/70) containing 5 g of 2,6-bis (tert-butyl) -4-methylphenol was added to stop the reaction.
The solvent was removed using a drum dryer to obtain a polymer D.
Table 1 shows the analysis results of the obtained polymer D.

[Comparative Example 1]
Instead of the above-mentioned “neodymium isostearate 2.7 mmol and diisobutylaluminum hydride 22.5 mmol”, neodymium isostearate 2.2 mmol and diisobutylaluminum hydride 18 mmol were used, and 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.) was used as a modifier. Product, trade name “KBM-403”) 11 mmol was used. Under other conditions, Polymer E was obtained in the same manner as in Example 1.
The measurement results of the obtained polymer E are shown in Table 1.
In the case of the modifier having no ester group, the terminal of the polymer was not modified at all, and the modification rate was zero.

[Comparative Example 2]
The inside of the fully dried 300 mL pressure-resistant mini cylinder was sufficiently replaced with dry nitrogen.
There, 130 mL of a 20% by mass cyclohexane solution containing 20 g of 1,3-butadiene, and isostearic acid (manufactured by Wako Pure Chemical Industries, Ltd., 2- (1,3,3-trimethylbutyl) -5,7,7 -Trimethyloctanoic acid) sodium salt and neodymium chloride were reacted with 1.9 mL of a 30% by mass cyclohexane solution containing 2.1 mmol of neodymium isostearate and shaken at room temperature for 5 minutes.
Subsequently, 22.5 mL of a 1 molar hexane solution containing 22.5 mmol of diisobutylaluminum hydride was further added and shaken, and then allowed to stand for 5 minutes.
After adding 6.3 mL of 1 mol hexane solution of ethylaluminum sesquichloride to Cl / Nd (molar ratio) = 3 and shaking, the mixture was allowed to stand for 20 minutes to obtain a coordination polymerization initiator solution. Prepared.
Next, the inside of the pressure-resistant autoclave with a stirrer having an inner volume of 11 L that was sufficiently dried was sufficiently replaced with dry nitrogen.
Thereto, 6 kg of a cyclohexane mixed solution containing 900 g of 1,3-butadiene was charged into an autoclave, and 167 mL of a coordination polymerization initiator solution prepared in advance was added, followed by polymerization at 50 ° C. for 2 hours.
After the polymerization reaction, 100 mL of a methanol / siloxane solution (30/70) containing 5 g of 2,6-bis (tert-butyl) -4-methylphenol was added to stop the reaction.
The solvent was removed using a drum dryer to obtain a polymer F.
Table 1 shows the analysis results of the obtained polymer F.

[Comparative Example 3]
Instead of the above-mentioned “neodymium isostearate 2.7 mmol, diisobutylaluminum hydride 22.5 mmol”, neodymium isostearate 2.2 mmol, diisobutylaluminum hydride 18 mmol, and N- (2-ethoxycarbonyl) ethyl-N-methyl- 3-aminopropyltriethoxysilane: 11 mmol was used. The polymer G was obtained by the same method as Example 1 under other conditions.
The measurement results of the obtained polymer G are shown in Table 1.

[Evaluation of Modified Conjugated Diene Polymer Composition]
The raw materials are blended in the proportions shown in Table 2 below, set to a bath temperature of 130 ° C., and a raw rubber as a first-stage kneading using a pressure type kneader “D0.3-3 type” manufactured by Moriyama. (Conjugated diene polymer, styrene-butadiene (SBR; manufactured by Asahi Kasei Chemicals Corporation, “Asaprene E15” natural rubber (adjusted to Mooney viscosity 60 by mastication)), SRAE oil, silica (manufactured by Evonik Degussa, “Ultra” Zir VN3 ") and silane coupling agent (Evonik Degussa," Si75 ") were added in this order and kneaded for 4 minutes.
Then, it dumped out at about 160 degreeC, and let it cool by rolling.
Subsequently, as the second stage kneading, the remaining raw materials excluding sulfur and the vulcanization accelerator were added and kneaded for 3 minutes.
Dumped out at about 160 ° C., passed through a roll and cooled.
After cooling, using a roll, sulfur (manufactured by Hosoi Chemical Co., Ltd.) and a vulcanization accelerator (manufactured by Ouchi Shinsei Chemical Co., Ltd., “Noxeller CZ-G” and “Noxeller DP”) are added at 170 ° C. Vulcanization was performed for 12 minutes to obtain a vulcanized rubber composition.
Formulation examples (S-1 to S-4) in each Example and Comparative Example are shown in Table 2 below, and the rubber composition before vulcanization and the vulcanized rubber composition obtained in each Example and each Comparative Example are shown. The performance evaluation results are shown in Tables 3 and 4 below.

The evaluation method was performed by the following method.
(1) Compound Mooney Viscosity The Mooney viscosity of the rubber composition before vulcanization described above was preheated for 1 minute at 100 ° C. using an L-shaped rotor according to JIS K6300-1, using a Mooney viscometer. Later, it was rotated at 2 revolutions per minute and the viscosity after 4 minutes was measured.
When the Mooney viscosity was a small value, it was judged that the energy consumed during kneading was small and the processability was good.

(2) Amount of bound rubber Rubber composition 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 (manufactured by 100 mesh wire mesh), and the mass was measured.
Then, after being immersed in toluene for 24 hours, a drying treatment was performed and the mass was measured.
Calculate the amount of rubber bound to the filler (modified conjugated diene polymer, SBR, natural rubber) from the amount of undissolved components, and determine the ratio of the rubber bound to the filler to the amount of rubber in the first blend. It was.
The larger the value, the more bound rubber.

(3) Tensile strength Measured by a tensile test method of JIS K6251 using a vulcanized test piece obtained by molding the vulcanized rubber composition described above.
It shows that it is excellent in fracture resistance, so that a numerical value is large.

(4) Viscoelasticity Using the vulcanized rubber composition produced as described above, “ARES viscoelasticity tester” manufactured by TA Instruments Co., Ltd. And tan δ at a measurement frequency of 10 Hz were measured by changing the strain in each of the case of high temperature (50 ° C.). In the case of low temperature (0 ° C.), tan δ was measured at a strain of 1%, and in the case of high temperature (50 ° C.), tan δ was measured at 3%.
The higher the tan δ (loss tangent) measured at a low temperature (0 ° C.) and a strain of 1%, the higher the wet skid resistance (that is, grip performance) is judged to be superior. In Example 4, Comparative Example 7 was evaluated using an index with a reference value of 100.
The lower the tan δ (loss tangent) measured at a high temperature (50 ° C.) and a strain of 3%, the smaller the hysteresis loss and the better the tire's low rolling resistance (that is, fuel economy). 3 and Comparative Example 5 in Table 4, and Comparative Example 7 in Table 4 were evaluated by an index with a reference value of 100.
The filler dispersibility is evaluated by ΔG ′ calculated by the difference between G ′ when the strain at high temperature (50 ° C.) is small (0.1%) and G ′ when the strain is large (10%), and the value is It was judged that the smaller the better.

(5) Abrasion resistance Abrasion resistance was tested in accordance with JIS K6264-2 using a vulcanized rubber composition manufactured as described above using an "Acron rubber abrasion tester" manufactured by Yasuda Seiki Seisakusho. Method A, load 44.1N, wear amount of 3000 rotations was measured.
In Table 3, Comparative Example 5 was evaluated, and in Table 4, Comparative Example 7 was evaluated using an index with a reference value of 100.
It was judged that the higher the index, the smaller the amount of wear and the better the wear resistance.

  As shown in Tables 3 and 4, it was confirmed that each example was excellent in fuel economy and wear resistance. On the other hand, it was confirmed that each comparative example was inferior in at least one of fuel economy and wear resistance.

  The modified conjugated diene polymer obtained by the production method of the present invention has industrial applicability as a raw material rubber for tires, etc., and the modified conjugated diene polymer composition of the present invention is a tire tread, side tire It has industrial applicability as materials for tire members such as walls, various seals including hoses, belts, shoe soles and windows, vibration damping rubber, and other industrial products. .

Claims (7)

Step (1): Using a coordination polymerization initiator, polymerizing a conjugated diene monomer to obtain a conjugated diene polymer,
Step (2): a step of reacting the conjugated diene polymer with four or more alkoxy groups bonded to a silyl group and a compound A containing a tertiary amino group and an ester group;
A process for producing a modified conjugated diene polymer.   The method for producing a modified conjugated diene polymer according to claim 1, wherein the coordination polymerization initiator contains an organic compound of a lanthanum series metal element. The method for producing a modified conjugated diene polymer according to claim 1 or 2, wherein the compound A is represented by the following formula (1).

... (1)

(In the formula ^(1), R 1 ~R ⁵ are each independently an alkyl group having a carbon 1 to 20, or an aryl group having 6 to 20 carbon atoms, R ⁶ to R ⁸ is 1 to 20 carbon atoms Represents an alkylene group, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, and the sum of m and r is 4 or more.)   A modified conjugated diene polymer obtained by the production method according to any one of claims 1 to 3. The modified conjugated diene polymer according to claim 4, which is represented by the following formula (2) or (3).

... (2)

(In the formula (2), P is a conjugated diene polymer having a 1,4-cis content of 80 mol% or more,
R ^{2 to} R ⁵ each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,
R ^{6 to} R ⁸ represent an alkylene group having 1 to 20 carbon atoms, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, m and r Is 4 or more. )

... (3)

(In the formula (3), P is a conjugated diene polymer having a 1,4-cis content of 80 mol% or more,
R ^{2 to} R ⁵ each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,
R ^{6 to} R ⁸ represent an alkylene group having 1 to 20 carbon atoms, n is an integer of 1 to 3, m is an integer of 1 to 3, r is an integer of 1 to 3, m and r Is 4 or more. ) 100 parts by mass of a rubber component containing 10 parts by mass or more of the modified conjugated diene polymer according to claim 4 or 5,
0.5 to 300 parts by mass of a silica-based inorganic filler,
A modified conjugated diene polymer composition.   A tire comprising the modified conjugated diene polymer composition according to claim 6.