JP2010209272A - Manufacturing method for conjugated diene based polymer, conjugated diene based polymer and conjugated diene based polymer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a conjugated diene based polymer having a structure unit based on a vinyl compound having a primary amino group and/or a secondary amino group and a structure unit based on a conjugated diene, and to provide a manufacturing method for a conjugated diene based polymer capable of reacting the conjugated diene with the vinyl compound even if protection treatment of the vinyl compound is not performed. <P>SOLUTION: In the manufacturing method for the conjugated diene based polymer, the conjugated diene is reacted with the vinyl compound having the primary amino group and/or the secondary amino group using an organic metal compound represented by following formula [I] or [II] as a polymerization initiator, provided that formula [I] is R<SP>1</SP><SB>4</SB>ZnM<SP>1</SP><SB>2</SB>and formula [II] is R<SP>2</SP><SB>4</SB>ZnM<SP>2</SP>. In the formulae [I] and [II], R<SP>1</SP>and R<SP>2</SP>each represent a substituent selected from the group consisting of substituents consisting of an alkyl group which may be substituted and an aryl group which may be substituted, M<SP>1</SP>represents an alkali metal, and M<SP>2</SP>represents an alkaline earth metal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In recent years, due to increasing interest in environmental issues, there has been a strong demand for fuel savings for automobiles, and polymer compositions used for automobile tires are also required to have excellent fuel economy. Yes. As a polymer composition for an automobile tire, a polymer composition containing a conjugated diene polymer such as polybutadiene or butadiene-styrene copolymer and a filler such as carbon black or silica is used. .

  As the conjugated diene polymer, a polymer produced by solution polymerization of a conjugated diene using an organometallic compound such as an organolithium compound as a polymerization initiator is widely used. Recently, a conjugated diene polymer in which an amino group that interacts with a filler is introduced into a polymer chain has been proposed as a conjugated diene polymer excellent in fuel efficiency. For example, as a method for producing a conjugated diene polymer in which a primary amino group or a secondary amino group is introduced into a polymer chain, a polymerization initiator using a compound having a primary amino group or a secondary amino group is used. In order to prevent deactivation, a compound having a primary amino group or a secondary amino group is previously treated with an alkali metal compound, and the active hydrogen of the primary amino group or the secondary amino group is replaced with an alkali metal. Patent Document 1 discloses a production method in which a protective treatment is performed, a compound subjected to the protective treatment is then reacted, and a hydrolysis treatment is performed after the reaction, in which an alkali metal introduced in the protective treatment is replaced with a hydrogen atom. ing.

JP 2004-182894 A

However, the method for producing a conjugated diene polymer in which the primary amino group or the secondary amino group described above is introduced into the polymer chain requires a protective treatment and further a hydrolysis treatment. Doing on a scale was not economically satisfactory.
Under the circumstances, the problem to be solved by the present invention is a conjugated diene system having a structural unit based on a vinyl compound having a primary amino group and / or a secondary amino group and a structural unit based on a conjugated diene. A method for producing a polymer, wherein a conjugated diene and a primary amino group and / or a secondary amino group are obtained without performing protection treatment of a vinyl compound having a primary amino group and / or a secondary amino group. A method for producing a conjugated diene polymer capable of reacting with a vinyl compound having a conjugated diene polymer produced by the production method, and a conjugated diene polymer composition containing the conjugated diene polymer. It is to provide.

The present invention relates to a vinyl compound having a conjugated diene and a primary amino group and / or a secondary amino group, using an organometallic compound represented by the following general formula [I] or [II] as a polymerization initiator: The present invention relates to a method for producing a conjugated diene polymer.
R ¹ ₄ ZnM ¹ ₂ [I]
R ² ₄ ZnM ² [II]
(In the above general formulas [I] and [II], R ¹ and R ² represent a substituent selected from a substituent group consisting of an optionally substituted alkyl group and an optionally substituted aryl group, 4 R ¹ and 4 R ² may be the same or different, M ¹ represents an alkali metal, and two M ¹ may be the same or different. M ² represents an alkaline earth metal.

  According to the present invention, there is provided a process for producing a conjugated diene polymer having a structural unit based on a vinyl compound having a primary amino group and / or a secondary amino group, and a structural unit based on a conjugated diene. A conjugate capable of reacting a conjugated diene with a vinyl compound having a primary amino group and / or a secondary amino group without subjecting the vinyl compound having an amino group and / or a secondary amino group to a protective treatment. A method for producing a diene polymer, a conjugated diene polymer produced by the production method, and a conjugated diene polymer composition containing the conjugated diene polymer can be provided.

  In the present invention, the term “polymerization” includes not only homopolymerization but also copolymerization, and the term “polymer” includes not only homopolymers but also copolymers.

In the production method of the present invention, an organometallic compound represented by the following general formula [I] or [II] is used as a polymerization initiator.
R ¹ ₄ ZnM ¹ ₂ [I]
R ² ₄ ZnM ² [II]
(In the above general formulas [I] and [II], R ¹ and R ² represent a substituent selected from a substituent group consisting of an optionally substituted alkyl group and an optionally substituted aryl group, 4 R ¹ and 4 R ² may be the same or different, M ¹ represents an alkali metal, and two M ¹ may be the same or different. M ² represents an alkaline earth metal.

In the general formulas [I] and [II], R ¹ and R ² represent a substituent selected from a substituent group consisting of an optionally substituted alkyl group and an optionally substituted aryl group. The four R ^{1 in} the general formula [I] may be the same or different, and the four R ^{2 in} the general formula [II] may be the same or different. Good.

  Examples of the alkyl group include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, isopentyl group, n-hexyl group, 2-ethylhexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group N-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group and n-eicosyl group.

  The number of carbon atoms in the alkyl group is preferably 1 to 4. The alkyl group is preferably a methyl group, an ethyl group, an isopropyl group, or a tert-butyl group.

  Examples of the aryl group include phenyl group, 2-tolyl group, 3-tolyl group, 4-tolyl group, 2,3-xylyl group, 2,4-xylyl group, 2,5-xylyl group, 2,6- Xylyl group, 3,4-xylyl group, 3,5-xylyl group, 2,3,4-trimethylphenyl group, 2,3,5-trimethylphenyl group, 2,3,6-trimethylphenyl group, 2,4 , 6-trimethylphenyl group, 3,4,5-trimethylphenyl group, 2,3,4,5-tetramethylphenyl group, 2,3,4,6-tetramethylphenyl group, 2,3,5,6 -Tetramethylphenyl group, pentamethylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, sec-butylphenyl group, tert-butylphenyl group, n-pen Butylphenyl group, neopentyl phenyl group, n- hexylphenyl group, n- octylphenyl group, n- decyl phenyl group, n- dodecyl phenyl group, n- tetradecyl phenyl group, a naphthyl group, and an anthracenyl group.

  The number of carbon atoms in the aryl group is preferably 6-12. The aryl group is preferably a phenyl group.

Of the four R ¹ 's in the general formula [I], at least two R ¹ are preferably tert-butyl groups. In general formula [II] of the four R ² in at least two R ² is preferably a tert- butyl group.

  In the general formula [I], Zn represents a zinc atom.

In the general formula [I], M ¹ represents an alkali metal, and two M ¹ may be the same or different. Examples of M ¹ include a lithium atom, a sodium atom, a potassium atom, a rubidium atom, and a cesium atom. M ¹ is preferably a lithium atom or a sodium atom.

In the general formula [II], M ² represents an alkaline earth metal. Examples of M ² include a beryllium atom, a magnesium atom, a calcium atom, a strontium atom, and a barium atom. M ² is preferably a magnesium atom.

  Examples of the organometallic compound represented by the general formula [I] include dilithium tetra-tert-butyl zincate, dilithium di-tert-butyldimethyl zincate, dilithium di-tert-butyl diethyl zincate, dilithium di-tert-butyl diisopropyl zincate, Examples thereof include dilithium di-tert-butyl diphenyl zincate, dilithium-tert-butyl trimethyl zincate, dilithium tri-tert-butyl methyl zincate, and compounds of these compounds in which lithium is sodium. The organometallic compound represented by the general formula [I] is preferably dilithium tetra-tert-butyl zincate, dilithium di-tert-butyldimethyl zincate, dilithium di-tert-butyl diethyl zincate, dilithium di-tert-butyl diisopropyl zincate. is there.

  Examples of the organometallic compound represented by the general formula [II] include magnesium tetra-tert-butyl zincate, magnesium di-tert-butyldimethyl zincate, magnesium di-tert-butyl diethyl zincate, magnesium di-tert-butyldiisopropyl. Examples include zincate and magnesium di-tert-butyldiphenyl zincate.

  Examples of the method for producing the organometallic compound represented by the general formulas [I] and [II] include a method described in JP-A No. 2004-292328. Moreover, as a manufacturing method of the organometallic compound represented by the general formula [I], a method in which an organozinc compound and an organoalkali metal compound are reacted at a molar ratio of 1: 2 in a hydrocarbon solvent or an ether compound solvent. As a method for producing the organometallic compound represented by the general formula [II], a molar ratio of an organozinc compound and an organoalkaline earth metal compound in a hydrocarbon solvent or an ether compound solvent is 1: 1. The method of making it react can be mention | raise | lifted.

  Examples of the organic zinc compound include dimethyl zinc, diethyl zinc, di-n-propyl zinc, diisopropyl zinc, di-n-butyl zinc, diisobutyl zinc, di-sec-butyl zinc, di-tert-butyl zinc, di- Examples thereof include n-pentyl zinc, dineopentyl zinc, diisopentyl zinc, di-n-hexyl zinc, di-2-ethylhexyl zinc, diphenyl zinc, ethylmethyl zinc, methylisopropyl zinc, methylphenyl zinc, and ethylisopropyl zinc. The organic zinc compound is preferably dimethyl zinc, diethyl zinc, diisopropyl zinc, or di-tert-butyl zinc.

  The organozinc compound is obtained by a known production method. For example, an organic alkali metal compound such as n-butyllithium and zinc chloride are reacted at a molar ratio of 2: 1, or an organic alkaline earth metal compound and zinc chloride are reacted at a molar ratio of 1: 1. Is obtained.

  Examples of the organic alkali metal compound include methyl lithium, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, isobutyl lithium, sec-butyl lithium, tert-butyl lithium, n-pentyl lithium, neopentyl lithium, Mention may be made of isopentyllithium, n-hexyllithium, 2-ethylhexyllithium, phenyllithium and their corresponding sodium compounds. The organic alkali metal compound is preferably tert-butyllithium.

  Examples of the organic alkaline earth metal compound include dimethyl magnesium, diethyl magnesium, di-n-propyl magnesium, diisopropyl magnesium, di-n-butyl magnesium, diisobutyl magnesium, di-sec-butyl magnesium, and di-tert-butyl magnesium. , Di-n-pentylmagnesium, dineopentylmagnesium, diisopentylmagnesium, di-n-hexylmagnesium, di-2-ethylhexylmagnesium, diphenylmagnesium, ethylmethylmagnesium, methylisopropylmagnesium, methylphenylmagnesium, ethylisopropylmagnesium Can give. The organic alkaline earth metal compound is preferably di-n-butylmagnesium.

  In the reaction between the organic zinc compound and the organic alkali metal compound and the reaction between the organic zinc compound and the organic alkaline earth metal compound, the reaction temperature is usually 0 ° C. or lower.

  In the polymerization, after the organometallic compound represented by the general formula [I] or [II] is prepared in advance, the organometallic compound represented by the general formula [I] or [II] is supplied to the polymerization reaction tank. Also good. An organozinc compound and an organoalkali metal compound are supplied to a polymerization reaction tank, and the organozinc compound and the organoalkali metal compound are reacted in the polymerization reaction tank to obtain an organometallic compound represented by the general formula [I]. It may be prepared. The organic zinc compound and the organic alkaline earth metal compound are supplied to the polymerization reaction tank, and the reaction between the organic zinc compound and the organic alkaline earth metal compound is performed in the polymerization reaction tank. Organometallic compounds may be prepared. In addition, zinc chloride and an organic alkali metal compound are supplied to a polymerization reaction tank, the reaction between zinc chloride and the organic alkali metal compound in the polymerization reaction tank, and the reaction between the organic zinc compound generated by the reaction and the organic alkali metal compound. To prepare an organometallic compound represented by the general formula [I]. Zinc chloride and an organic alkaline earth metal compound are supplied to a polymerization reactor, and the reaction between zinc chloride and the organic alkaline earth metal compound in the polymerization reactor and the organic zinc compound and organic alkaline earth produced by the reaction are performed. An organometallic compound represented by the general formula [II] may be prepared by reacting with a metal compound.

  In the production method of the present invention, a conjugated diene is reacted with a vinyl compound having a primary amino group and / or a secondary amino group. Examples of the conjugated diene include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and 1,3-hexadiene. These may be used alone or in combination of two or more. From the viewpoint of availability, 1,3-butadiene and 2-methyl-1,3-butadiene are preferable.

  Examples of the vinyl compound having a primary amino group include allylamine, acrylamide, methacrylamide, 3-butenamine, 2-methylallylamine, 2-methylenebutanamide, and 4-methyleneglutamic acid. The vinyl compound is preferably a compound having a carbonyl group at the α-position of the vinyl group. As the vinyl compound, acrylamide, methacrylamide, 2-methylenebutanamide, and 4-methyleneglutamic acid, which are compounds having a carbonyl group at the α-position of the vinyl group, are particularly preferable.

  Examples of the vinyl compound having a secondary amino group include N-allylmethylamine, N-allylethylamine, N-methylacrylamide, N-vinylacetamide, N-vinylurea, N-ethylacrylamide, N-isopropylacrylamide, N Examples include -n-butylacrylamide, N-tert-butylacrylamide, N-methylmethacrylamide, and N, N-dimethylaminoethylacrylamide. Examples of the vinyl compound include N-ethylacrylamide, N-isopropylacrylamide, Nn-butylacrylamide, N-tert-butylacrylamide, N-methylmethacrylamide, N-containing compounds having a carbonyl group at the α-position of the vinyl group. N-dimethylaminoethylacrylamide is particularly preferred.

  In the production method of the present invention, other vinyl compounds may be reacted in addition to the conjugated diene and the vinyl compound having a primary amino group and / or a secondary amino group. Examples of other vinyl compounds include aromatic vinyl compounds, vinyl nitriles, unsaturated carboxylic acid esters, and the like. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, divinyl benzene, trivinyl benzene, and divinyl naphthalene. Examples of the vinyl nitrile include acrylonitrile, and examples of the unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. In these, an aromatic vinyl compound is preferable and a styrene is preferable from a viewpoint of availability.

  About content of the structural unit in a conjugated diene polymer, Preferably, content of the structural unit based on a conjugated diene is 1 to 99 weight%, and has a primary amino group and / or a secondary amino group. The content of structural units based on vinyl compounds is 0.01 to 10% by weight, and the content of structural units based on other vinyl compounds is 0 to 99.99% by weight.

  The solvent used in the production method of the present invention is preferably a hydrocarbon. Examples of the hydrocarbon include aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons. Examples of the aliphatic hydrocarbon include propane, n-butane, isobutane, n-pentane, isopentane, and n-hexane. Examples of the aromatic hydrocarbon include benzene, toluene, xylene, and ethylbenzene. Examples of the alicyclic hydrocarbon include cyclopentane and cyclohexane. These may be used alone or in combination of two or more. Of these, hydrocarbons having 3 to 12 carbon atoms are preferred.

  The solvent used in the production method of the present invention preferably does not contain cyclic ethers such as tetrahydrofuran.

  The polymerization temperature in the production method of the present invention is usually -80 to 150 ° C, preferably 0 to 100 ° C.

  The polymerization time in the production method of the present invention is usually 5 minutes to 48 hours, preferably 30 minutes to 24 hours.

  After completion of the polymerization, a known recovery method, for example, (1) a method of adding a coagulant to the polymerization reaction solution, (2) a method of adding steam to the polymerization reaction solution, (3) from the polymerization reaction solution using an oven dryer The conjugated diene polymer can be recovered from the polymerization reaction solution by the method of removing the solvent. The recovered conjugated diene polymer may be dried by a known dryer such as a band dryer or an extrusion dryer.

The vinyl bond content of the conjugated diene polymer is preferably 80 mol% or less, more preferably 70 mol% or less from the viewpoint of fuel efficiency, with the content of the conjugated diene unit being 100 mol%. Moreover, from a viewpoint of grip property, Preferably it is 20 mol% or more, More preferably, it is 40 mol% or more. The vinyl bond amount can be increased by adding an amine compound or an ether compound. The vinyl bond amount is determined from the absorption intensity in the vicinity of 910 cm ^−1, which is the vinyl group absorption peak, by infrared spectroscopy.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the conjugated diene polymer is preferably 10 or more, more preferably 20 or more, from the viewpoint of strength. Moreover, from a viewpoint of workability, Preferably it is 200 or less, More preferably, it is 150 or less. The Mooney viscosity (ML _{1 + 4} , 100 ° C.) is measured at 100 ° C. according to JIS K6300 (1994).

  The molecular weight distribution of the conjugated diene polymer is preferably 1 to 10 from the viewpoint of fuel economy.

  The conjugated diene polymer may be blended with additives and other polymers to form a polymer composition.

  Known additives may be used, such as sulfur vulcanizing agents; vulcanization accelerators such as thiazole vulcanization accelerators, thiuram vulcanization accelerators, sulfenamide vulcanization accelerators; Vulcanization activators such as stearic acid and zinc oxide; organic peroxides; reinforcing agents such as carbon black and silica; fillers such as calcium carbonate and talc; silane coupling agents; extension oils; processing aids; Agents: Lubricants can be exemplified.

  When a conjugated diene polymer composition is prepared by blending a conjugated diene polymer with a filler, the filler content is preferably 100 parts by weight of the conjugated diene polymer from the viewpoint of wear resistance and strength. It is 10 parts by weight or more, more preferably 20 parts by weight or more, and further preferably 30 parts by weight or more. Moreover, from a viewpoint of improving reinforcement, Preferably it is 150 weight part or less, More preferably, it is 120 weight part or less, More preferably, it is 100 weight part or less.

  Other polymers include conjugated diene polymers produced by methods other than the production method of the present invention, natural rubber, ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-1-hexene copolymers. Examples thereof include a polymer, a propylene-1-butene copolymer, and an ethylene-propylene-1-butene copolymer. These polymers may be used in combination of two or more.

  The conjugated diene polymer and conjugated diene polymer composition of the present invention are suitably used for tires, belts, hoses, footwear and the like.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

The polymer and the vulcanized sheet were evaluated by the following method.
1. Mooney viscosity (ML _{1 + 4} 100 ° C)
It measured at 100 degreeC according to JISK-6300 (1994).
2. Styrene unit content Measured according to JIS K-6383 (refractive index method).
3. Vinyl group content Measured by infrared spectroscopy (Morello method). In the measurement, the absorption intensity in the vicinity of 910 cm ^−1, which is the vinyl group absorption peak, was measured with an infrared spectrophotometer.
4). Fuel saving properties Using a viscoelasticity measuring device (manufactured by Ueshima Seisakusho), a loss tangent (tan δ (70 ° C)) of 70 ° C was measured under the conditions of 1% strain and 10 Hz frequency.

Example 1
(Synthesis of Et ₂ tert-Bu ₂ ZnLi ₂ )
The inside of the 100 ml eggplant flask was replaced with dry nitrogen. In an eggplant flask, 20 ml of diethyl ether and 1.0 mmol of diethyl zinc were added, and then 2.0 mmol of tert-butyllithium was added at -78 ° C. The solution in the eggplant flask was stirred at 0 ° C. for 30 minutes to obtain a diethyl ether solution of Et ₂ tert-Bu ₂ ZnLi ₂ .
(Polymer synthesis)
The interior of the stainless steel polymerization reactor having an internal volume of 5 liters was washed and dried and replaced with dry nitrogen. Next, 2.55 kg of hexane, 375 g of 1,3-butadiene, 125 g of styrene, 1.46 g of N, N, N ′, N′-tetramethylethylenediamine, and Et ₂ tert-Bu ₂ ZnLi ₂ obtained by the above method. A diethyl ether solution containing 1.0 mmol was added, and polymerization was carried out at 65 ° C. for 3 hours with stirring. Next, 0.23 g of N-isopropylacrylamide was added, and the reaction was performed with stirring for 15 minutes. 10 ml of methanol was added and stirred for 5 minutes. The polymerization reaction solution in the polymerization reaction tank is taken out, 3 g of an antioxidant (Sumitomo Chemical Co., Ltd., Sumitizer GM 2 g, Sumitomo Chemical Co., Ltd., Sumitizer TP-D 1 g) is added, and most of the hexane is evaporated, at 55 ° C. for 12 hours. The polymer was obtained by drying under reduced pressure. Table 1 shows the measurement results of the physical properties of the polymer.

(Preparation of polymer composition and vulcanized sheet)
100 parts by weight of the obtained polymer, 50 parts by weight of carbon black (manufactured by Mitsubishi Chemical Corporation, trade name: N-339), 10 parts by weight of extender oil (trade name: X-140), anti-aging agent 1 part by weight (manufactured by Sumitomo Chemical Co., Ltd., trade name: Antigen 3C), 4 parts by weight of zinc white, 2 parts by weight of stearic acid, 1 part by weight of a vulcanization accelerator (trade name: Soxinol CZ made by Sumitomo Chemical), wax ( Ouchi Shinsei Chemical Co., Ltd., trade name: Sannok N) 1.5 parts by weight and 1.75 parts by weight of sulfur were kneaded in a lab plast mill to obtain a polymer composition. The polymer composition was formed into a sheet with a 6-inch roll. Next, the sheet was heated and vulcanized at 160 ° C. for 15 minutes to obtain a vulcanized sheet. The fuel efficiency of the vulcanized sheet was evaluated. The evaluation results are shown in Table 1.

Comparative Example 1
Instead of 1.46 g of N, N, N ′, N′-tetramethylethylenediamine, 1.35 g of tetrahydrofuran and 0.90 g of ethylene glycol diethyl ether were added. Et ₂ tert-Bu ₂ ZnLi ₂ 1.0 Example 1 except that a hexane solution containing 3.3 mmol of n-BuLi was added instead of the diethyl ether solution containing mmol and that the amount of N-isopropylacrylamide added was changed to 0.38 g. went. Table 1 shows the evaluation results of the polymer and the vulcanized sheet.

Claims (8)

Conjugation in which a conjugated diene is reacted with a vinyl compound having a primary amino group and / or a secondary amino group using an organometallic compound represented by the following general formula [I] or [II] as a polymerization initiator A method for producing a diene polymer.
R ¹ ₄ ZnM ¹ ₂ [I]
R ² ₄ ZnM ² [II]
(In the above general formulas [I] and [II], R ¹ and R ² represent a substituent selected from a substituent group consisting of an optionally substituted alkyl group and an optionally substituted aryl group, 4 R ¹ and 4 R ² may be the same or different, M ¹ represents an alkali metal, and two M ¹ may be the same or different. M ² represents an alkaline earth metal. 2. The conjugated diene system according to claim 1, wherein at least two R ¹ out of four R ¹ are tert-butyl groups, and at least two R ² out of four R ² are tert-butyl groups. A method for producing a polymer. The method for producing a conjugated diene polymer according to claim 1 or 2, wherein M ¹ is a lithium atom or a sodium atom, and M ² is a magnesium atom.   The manufacturing method of the conjugated diene polymer in any one of Claims 1-3 superposed | polymerized in a hydrocarbon solvent.   The conjugated diene-based heavy component according to any one of claims 1 to 4, wherein the conjugated diene is at least one conjugated diene selected from the conjugated diene group consisting of 1,3-butadiene and 2-methyl-1,3-butadiene. Manufacturing method of coalescence.   A conjugated diene polymer produced by the method for producing a conjugated diene polymer according to claim 1.   The conjugated diene polymer according to claim 6, wherein the content of the structural unit based on the conjugated diene is 100 mol%, and the vinyl bond content is 20 to 80 mol%.   A conjugated diene polymer composition comprising the conjugated diene polymer according to claim 6 or 7 and a filler.