JP2759812B2 - Method for producing conjugated diene polymer and catalyst for conjugated diene polymerization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a monomer having a conjugated diene as a main component,
Polymerization is carried out using a catalyst system comprising (a) an organolithium aluminum compound, (b) an organobarium aluminum compound, and (c) a lithium compound to obtain a high content of trans-1,4 bonds and a low content of 1,2. Also, the present invention relates to a method for producing a conjugated diene-based polymer having 3,4 bonds (hereinafter referred to as "vinyl bond"), and a conjugated diene polymerization catalyst useful for this polymerization.

[Conventional technology]

In recent years, as the performance of automobiles has become higher, there has been an increasing demand for rubber materials such as tires to be improved in workability, wear resistance, mechanical properties, and the like.

In order to satisfy these characteristics, high cis-1,4-polybutadiene obtained using a conventional Ziegler-type catalyst, low cis-1,4-polybutadiene obtained using a lithium-based catalyst, and styrene / butadiene must be used. It was difficult with a polymer or a polybutadiene or styrene-butadiene copolymer obtained by emulsion polymerization.

On the other hand, besides the above-mentioned polymers, polybutadiene and styrene-butadiene copolymer having a high trans-1,4 bond content are known, but these polymers have various vulnerabilities such as unsatisfactory vulcanization properties or extremely difficult production methods. There is a problem,
Not practical.

As conventional polymerization catalysts having a high trans-1,4 bond content and capable of copolymerizing a conjugated diene and an aromatic vinyl compound, the following alkaline earth metal catalysts, especially barium catalysts, are known.

(I) Barium metal-based catalyst system (a) P. Maleki et al. Reported a copolymerization reaction of styrene and 1,3-butadiene using a suspension of barium metal in toluene as a catalyst. [Makromol. Chem., 156 , 31 (197
2)], there is a problem that the polymerization activity is low.

(Ii) A catalyst system comprising a compound containing a barium-heteroatom bond and an organic metal as main components. (B) Fujio et al. Reported that Ba (OC ₂ H ₅ ) ₂ or And n-butyllithium (hereinafter referred to as “n-BuLi”) as a polymerization catalyst, and reported a copolymerization reaction between styrene and 1,3-butadiene (Nippon Kagaku Magazine, 447).
(1972)], which has a problem that the trans-1,4 bond content is as low as about 70% or less.

(C) As an example of a polymerization catalyst for a barium alkoxide and an organic metal, ZMBaidakova et al. (C ₂ H ₅ ) ₂ Mg / Ba (OC
₂ H _{5) 2 system, C 4 H 9 MgI / Ba} (OC 2 H 5) 2 / diphenyl ethylene, and _{(n-C 6 H 13)} 2 Mg / Ba (OC 2 H 5) 2 / diphenyl ethylene A polymerization reaction of 1,3-butadiene with a catalyst has been reported (Polymer Sci., USSR, 18 , 2325 (197
6)], the polymerization activity is very low.

(D) Japanese Patent Publication No. 52-48910 discloses that barium tertiary alkoxide and dibutyl manesium are used as polymerization catalysts.
Although a copolymerization reaction of styrene and 1,3-butadiene is disclosed, the activity is also low in this reaction.

(E) In Japanese Patent Publication No. 56-45401, (Wherein, R is the same or different, at least one R is a methyl group or a cyclohexyl group, and the remaining Rs are selected from the group consisting of an alkyl group having 1 to 6 carbon atoms and a cyclohexyl group; The molar ratio is about 97.5: 2.5 to 90:10), and a copolymerization reaction of styrene and 1,3-butadiene using a polymerization catalyst of a barium compound represented by the formula: It is very complicated to introduce an -OH group into a barium compound, and the trans-1,4 bond content is about 80% or less, which is not practical.

(F) JP-B-62-35401 discloses a catalyst system of barium alkoxide, trialkylaluminum and dialkylmagnesium, but it is very difficult to prepare a barium compound and the polymerization activity is low. It is a problem.

(G) JP-A-52-30543 discloses a copolymerization reaction of styrene with 1,3-butadiene using an organolithium, barium compound and organoaluminum compound as a polymerization catalyst.

However, in order to make the trans-1,4 bond content relatively high, it is necessary to increase the proportion of the organoaluminum compound to be used. Also has the disadvantage of being reduced.

(H) On the other hand, Tsuruta et al. Describe an R (CH ₂ CH ₂ O) _n Li / n-BuLi system,
Or styrene using (CH ₃ ) ₂ NCH ₂ CH ₂ OLi / n-BuLi catalyst
It reports a copolymerization reaction with 1,3-butadiene [Industrial Chemistry, 72 , 994 (1969); J. Macromol. Sci. Chem., A4 ,
885 (1970)].

Further, Japanese Patent Publication No. 57-34843 discloses a combination of a barium compound / organoaluminum compound / organic lithium compound / lithium alkoxide catalyst based on the knowledge of Tsuruta et al. And the knowledge of Japanese Patent Publication No. 52-30543. Styrene-butadiene copolymerization as well as butadiene polymerization are disclosed.

(I) Japanese Patent Publication No. 60-26406 discloses a barium compound /
Styrene-butadiene copolymerization with an organolithium / magnesium compound / organic lithium compound / organoaluminum compound catalyst has been disclosed, but has the disadvantage of low trans-1,4 bond content and low molecular weight.

(N) JP-A-56-112916 discloses a barium compound /
Although butadiene polymerization using an organolithium / magnesium compound / organoaluminum compound catalyst is disclosed, there is a problem that the molecular weight is hard to increase.

(Iii) Catalyst system mainly composed of barium art complex (L) Fujio et al. Describe an art complex (ate-complex) such as barium zinc tetrabutyl [BaZn (C ₄ H ₉ ) ₄ ].
Used a polymerization catalyst [Nippon Kagaku Magazine, 440 (1972)]. Further, ZMBaidakova et al. Used an art complex such as Ba [Al (C ₂ H ₅ ) ₄ ] ₂ in a hydrocarbon or electron donor solvent as a polymerization catalyst. [Polymer Sci., USSR, 16 , 2630 (1974)], reports the copolymerization of butadiene-styrene. The former has a low trans-1,4 bond content of about 70% or less, and the latter has a low polymerization rate. There is a problem that the reaction is slow and the conversion of the monomer is very low at 75% in the reaction at 50 ° C. for 100 hours.

(ヲ) JP-A-60-2323 discloses the aforementioned ZMBaidakov
Similarly to the method of a et al., butadiene polymerization using an organic barium aluminum compound (art complex) / electron donor catalyst is disclosed, but the polymerization activity is still low and is not suitable for practical use.

(W) JP-A-59-17724 discloses an organic lithium compound / organic barium aluminum compound (art complex).
Butadiene polymerization using a system catalyst is disclosed, but the trans-1,4 bond content is as low as 80% or less, and trans-1,4
Poor control of binding content.

As described above, many conjugated diene-based polymers using a catalyst system containing a barium compound as a main component have been proposed.However, the polymerization activity is low, the trans-1,4 bond content is low, and the crystal melting point is controlled. Alternatively, there is a problem that it is difficult to control the molecular weight.

[Problems to be solved by the invention]

The present invention has been made in view of the above-mentioned conventional technical problems, and has a high trans-1,4 bond content, easy controllability, high polymerization activity, and easy control of molecular weight. An object of the present invention is to provide a method for producing a system polymer and a catalyst for conjugated diene polymerization.

[Means for solving the problem]

The present invention provides the following components (a), (b) and (c)
A method for producing a conjugated diene-based polymer in which a monomer having a conjugated diene as a main component is polymerized in an inert organic solvent using a catalyst composition containing the components, and a polymerization catalyst for a conjugated diene comprising the catalyst composition. To provide.

(A) An organic lithium aluminum compound represented by the general formula LiAlR ¹ R ² R ³ R ⁴ (wherein R ^{1 to} R ⁴ are the same or different and represent an alkyl group or an aryl group having 1 to 20 carbon atoms) .

(B) General formula Ba (AlR ¹ R ² R ³ R ⁴ ) ₂ or Ba [AlR ¹ R ² R
³ (OR ⁴ )] ₂ (wherein, R ^{1 to} R ⁴ are the same as above).

(C) A lithium compound represented by the general formula LiOR ⁵ (wherein, R ⁵ represents an alkyl group or an aryl group having 1 to 20 carbon atoms, or a hydrocarbon group having an oxygen atom and / or a nitrogen atom).

The catalyst system used for producing the conjugated diene-based polymer of the present invention includes (a) an organolithium aluminum compound (art complex, hereinafter referred to as “component (a)”), and (b) an organic barium aluminum compound (art). Complex, hereinafter “(b)
Component)) and (c) a lithium compound (hereinafter referred to as "component (c)").

First, the organolithium aluminum compound as the component (a) is synthesized by reacting an organolithium compound with a trialkylaluminum.

Here, examples of the organic lithium compound include ethyl lithium, propyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, hexyl lithium, 1,4-dilithiobutane, a reaction product of butyl lithium with divinylbenzene, and an alkyl. Examples thereof include range lithium, phenyl lithium, stilbene dilithium, isopropenyl benzene dilithium, and lithium naphthalene.

Further, specific examples of trialkyl aluminum include:
Examples include trimethylaluminum, triethylaluminum, triisopropylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, tricyclohexylaluminum and the like.

The amount of the organolithium compound and the trialkylaluminum used is 0.
An organolithium aluminum compound (art complex) can be synthesized by reacting 8-1.5 moles, preferably equimolar, of a trialkylaluminum in an organic solvent such as cyclohexane or tetrahydrofuran.

The reaction can be carried out at a temperature of -80 to 120 ° C, preferably -20 to 100 ° C, and preferably in an inert atmosphere such as nitrogen gas.

Next, as the organic barium aluminum compound as the component (b), for example, the method of Lehmkhol et al. [Ann. 705 , 42
(1967)] to react the barium compound with the trialkylaluminum.

Here, as the barium compound, specifically, barium dimethoxide, barium diethoxide, barium diisopropoxide, barium di-n-butoxide, barium disec-butoxide, barium di-t-butoxide, barium di (1,1-dimethylpropoxide) Barium di (1,2-dimethylpropoxide), barium di (1,1-dimethylbutoxide), barium di (1,1-dimethylpentoxide), barium di (2-ethylhexanoxide), barium di (1-methyl) Heptoxide), barium diphenoxide, barium di (p-methylphenoxide), barium di (p-butylphenoxide), barium di (o-methylphenoxide), barium di (p-octylphenoxide), barium di (p-nonylphenoxide), barium di (P-dodeci Phenoxide),
Barium di (α-naphthoxide), barium di (β-naphthoxide), barium di (o-methoxyphenoxide), barium di (m-methoxyphenoxide, barium di (p-methoxyphenoxide), barium di (o-ethoxyphenoxide), barium di (4-methoxy- 1
-Naphthoxide).

Examples of the trialkylaluminum used for the component (b) include the same compounds as those used for synthesizing the ate complex of the component (a).

This barium compound and trialkyl aluminum
2 to 6 moles, preferably 2.5 moles relative to the barium compound
An organic barium-aluminum compound (art complex) can be synthesized by reacting a 5.0-fold molar amount of a trialkylaluminum in an organic solvent such as cyclohexane or tetrahydrofuran. The reaction can be carried out at a temperature of -80 to 120 ° C, preferably -20 to 100 ° C, and is preferably performed in an inert atmosphere such as nitrogen gas.

Next, (c) the lithium compound can be synthesized by reacting an organic lithium compound, lithium metal or lithium hydride with an alcohol,
Preferably, the following general formula (Wherein, R ^{1 to} R ³ are the same as above or a hydrogen atom, and n represents an integer of 1 to 3), (Wherein, R ^{1 to} R ³ are the same as described above or a hydrogen atom, R ⁶ is the same as R ^{1 to} R ⁴ , and n is the same as described above), R ¹ _mN -[(CH ₂ ) _n -OLi] _3-m (wherein, R ¹ and n are the same as above, and m represents an integer of 1 or 2); (Wherein, R ⁷ is an alkylene group having 3 to 10 carbon atoms, and n is the same as described above); (Wherein, R ⁸ and R ⁹ represent an alkylene group having 2 to 5 carbon atoms, and n is the same as described above); (Wherein R ⁸ , R ⁹ and n are the same as above), Wherein R ⁸ , R ⁹ and n are the same as above. (Wherein, R ^{1 and} R ² are the same as above or a hydrogen atom, and n is the same as above).

These lithium compounds can be used alone or in combination of two or more.

The organic lithium compound used in the synthesis of the lithium compound (c) includes the organic lithium compound used in the synthesis of the component (a).

Specific examples of alcohols include t-butanol, sec-butanol, cyclohexanol, octanol, 2-ethylhexanol, p-cresol, m-
Cresol, nonylphenol, hexylphenol,
Tetrahydrofurfuryl alcohol, furfuryl alcohol, 3-methyl-tetrahydrofurfuryl alcohol, 4-ethyl-tetrahydrofurfuryl alcohol,
Oligomers of tetrahydrofurfuryl alcohol, ethylene glycol monophenyl ether, ethylene glycol monobutyl ether, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N, N-diphenylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, N-phenyldiethanolamine, N, N-dimethylpropanolamine, N, N-dibutylpropanolamine, N-methyldipropanolamine, N-ethyldipropanolamine, 1- (2-hydroxyethyl) pyrrolidine, 2
-Methyl-1-hydroxyethyl) pyrrolidine, 2
-Methyl-1- (3-hydroxypropyl) pyrrolidine, 1-piperidineethanol, 1-piperidinepropanol, 2-ethyl-1-piperidinepropanol, 2
-Phenyl-1-piperidineethanol, N-β-hydroxyethylmorpholine, 2-ethyl-N-β-hydroxyethylmorpholine, 1-piperazineethanol,
-Piperazinepropanol, N, N'-bis ([beta] -hydroxyethyl) piperazine, N, N'-bis ([gamma] -hydroxypropyl) piperazine, 2-([beta] -hydroxyethyl) pyridine, 2-([gamma] -hydroxypropyl) Pyridine and the like can be mentioned.

The amount of the organic lithium compound, lithium metal or lithium hydride, and the alcohol used is such that the hydroxyl group of the alcohol is used in an amount of 0.5 to 1.5 equivalents, preferably equivalent, to the lithium atom, and is reacted in an organic solvent such as cyclohexane or tetrahydrofuran. Can synthesize a lithium compound. The reaction can be carried out at a temperature of −80 to 100 ° C., preferably −20 to 100 ° C., and is preferably performed in an inert atmosphere such as nitrogen gas.

Incidentally, the composition of the catalyst composition used in the present invention,
The molar ratio of component (a) / component (b) is preferably 2.5-5.
If it is less than 2.5, the polymerization activity will be low. On the other hand, if it exceeds 5.0, the trans-1,4 bond content of the obtained polymer will be low.

Further, the molar ratio of component (a) / component (c) is preferably from 0.5 to 10.0, and more preferably from 1.0 to 6.0. When the molar ratio is less than 0.5, the polymerization activity is low. The trans-1,4 bond content may be low.

Further, the amount of the catalyst composition of the present invention to be used is generally 0.05 to 4.0 mmol, preferably about 0.1 to 3.0 mmol, per 100 B of the monomer used.

Further, as a catalyst component, in preparing the catalyst, in addition to the components (a), (b) and (c), a conjugated diene may be added, if necessary, at a ratio of 0.05 to 20 mol per 1 mol of the component (b). May be used. The conjugated diene used for catalyst preparation is
The same isoprene, 1,3-butadiene, 1,3-pentadiene and the like as the monomers for polymerization are used. Although a conjugated diene as a catalyst component is not essential, the combined use thereof further improves the catalytic activity of the catalyst component.

Preparation of the catalyst comprises, for example, reacting the components (a) to (c) dissolved in an inert organic solvent and, if necessary, a conjugated diene. At that time, the order of addition of each component may be arbitrary. These components are preferably mixed, reacted and aged in advance for the purpose of improving polymerization activity and shortening the period of induction of polymerization initiation.However, during the polymerization, the catalyst components may be directly added directly to the solvent and the monomer. Good.

Conjugated dienes that can be polymerized with the catalyst system of the present invention include 1,1
3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, myrcene, etc.,
They can be used alone or in combination of two or more.
Butadiene and / or isoprene are preferred.

The conjugated diene polymer used in the present invention includes:
In addition to the conjugated diene, in addition to vinyl aromatic compounds such as styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, p-butylstyrene, and vinylnaphthalene, vinylpyridine, acrylonitrile, methacrylonitrile, and meryl (meth) ) It is possible to copolymerize acrylates, acrylates and the like, preferably vinyl aromatic compounds, especially styrene.

The polymerization solvent is an inert organic solvent, for example, an aromatic hydrocarbon solvent such as benzene, toluene and xylene; an aliphatic hydrocarbon solvent such as n-pentane, n-hexane, n-butane and cyclohexane; and methylcyclohexane. Alicyclic hydrocarbon solvents such as pentane and cyclohexane and mixtures thereof can be used.

The polymerization temperature is usually -20 ° C to 150 ° C, preferably 30 ° C.
~ 120 ° C. The polymerization reaction may be a batch type or a continuous type.

The monomer concentration in the solvent is usually 5 to 50% by weight,
Preferably it is 10 to 35% by weight.

In addition, in order to prevent the deactivation of the catalyst system and the polymer of the present invention in producing the polymer, consideration should be given to minimizing the incorporation of compounds having a deactivating effect such as oxygen, water or carbon dioxide gas into the polymerization system. is required.

In the present invention, a conjugated diene is homopolymerized or an aromatic vinyl compound such as styrene and a conjugated diene are copolymerized in an inert organic solvent using the catalyst system comprising the components (a) to (c). To form a conjugated diene polymer.

The conjugated diene polymer thus obtained has a trans bond content of the diene portion of 70 to 90%, preferably 75 to 90%.
87%, vinyl bond content 4-10%, preferably 5-9
%, When the aromatic vinyl compound is copolymerized, the bound aromatic vinyl compound content is 50% by weight or less, preferably 5 to 45% by weight, more preferably 10 to 35% by weight. In the case of styrene, the styrene chains are preferably random.

If the trans-1,4-bond content of the diene portion of the conjugated diene polymer is less than 70%, the tensile strength and abrasion resistance are poor, while if it exceeds 90%, the resin becomes resinous and the hardness increases, and the vulcanized rubber Physical properties decrease.

If the vinyl bond content of the polymer is less than 4%, it is technically difficult to produce the polymer, while if it exceeds 10%, the tensile strength and wear resistance are poor.

Further, the bound aromatic vinyl compound content of the polymer is:
From the viewpoint of the tensile strength and rebound resilience of the vulcanized rubber, the content is preferably 5 to 45% by weight.

Further, the conjugated diene-based polymer produced has a random styrene chain when styrene is copolymerized. For example, the oxidative decomposition method of IM Kolthoff et al. (J. Polym. Sc
i., 1, 429 (1946 )) block polystyrene content in the copolymer measured at 10 wt% or less, preferably 5 wt% or less, the vulcanized when long blocks of polystyrene exceeds 10 wt% The rebound resilience of the object decreases.

The high trans bond content of the diene moiety of the conjugated diene-based polymer according to the present invention is supported by the high crystal melting point obtained by differential scanning calorimetry analysis.

Further, the molecular weight of the conjugated diene-based polymer obtained in the present invention can be changed over a wide range, the weight average molecular weight in terms of polystyrene is usually 5 × 10
^{4 to} 100 × 10 ⁴ , preferably 10 × 10 ⁴ to 80 × 10 ⁴ and 5
If it is less than × 10 ⁴ , the tensile strength, abrasion resistance, rebound resilience, and heat generation of the vulcanized rubber are inferior, while if it exceeds 100 × 10 ⁴ , the workability is inferior, and the torque is excessive when kneading with rolls or Banbury. In addition, the temperature of the composition becomes high and the composition deteriorates, and the dispersion of carbon black becomes poor, resulting in poor performance of the vulcanized rubber.

Furthermore, when the conjugated diene-based polymer obtained in the present invention is used particularly as an industrial rubber product, its Mooney viscosity (ML _{1 + 4} , 100 ° C.) is usually 20 to 150, preferably 30 to 8
When it is less than 20, the physical properties of the vulcanized rubber are inferior, and when it exceeds 150, the processability is inferior.

The conjugated diene-based polymer obtained according to the present invention is obtained by blending the polymer alone or blended with other synthetic rubber or natural rubber as a raw material rubber, if necessary, oil-extending with a process oil, and then filling. A rubber composition is prepared by adding a conventional vulcanized rubber compounding agent such as carbon black, a vulcanizing agent and a vulcanization accelerator, and vulcanized, and is used for rubber applications requiring mechanical properties and abrasion resistance. Can be used.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

Various measurements in the examples were based on the following methods.

The microstructure of the conjugated diene polymer was determined by an infrared absorption spectrum method (Morello method).

The crystal melting point [Tm] of the conjugated diene polymer was measured using a differential scanning calorimeter (DSC).

Here, as a differential calorimeter, a 910 type Differential Scanning Calorimeter manufactured by DuPont, USA was used.
As a recorder, a 990 type thermal analyzer (Thermal Analyzer) manufactured by DuPont was used. Sample size is 1
0.0mg ± 0.1mg, α-alumina [Shimadzu Corporation, DSC standard sample] 10.15 on the reference side
mg was used. The measurement is performed by inserting the sample and reference into an aluminum holder (Dupont) at room temperature
And heated to + 180 ° C, then 10 ° C per minute
After cooling to −140 ° C. at a rate of, the sample was analyzed at a rate of temperature rise of 20 ° C. per minute and a sensitivity of 2 mV / cm.

Mooney viscosity was measured at a preheating time of 1 minute, a measurement time of 4 minutes, and a temperature of 100 ° C. (according to JIS K 6300).

Example 1 Preparation of Catalyst Component (a) -1 100 ml in a 300 ml eggplant type flask under a dry nitrogen atmosphere
Was added, and 10 ml of a 1.0 mol / triethylaluminum cyclohexane solution was added.

Next, while cooling in an ice bath, 6.3 ml of a 1.6 mol / n-butyllithium n-hexane solution was added dropwise and left for 30 minutes. The resulting white powder was washed with cyclohexane and dried.

The ratio of lithium atoms to aluminum atoms in the obtained powder was approximately 1: 1.

Preparation of catalyst component (b) -1 Using the same apparatus as above, into 100 ml of cyclohexane
10 ml of a 1.0 mol / nonylphenoxybarium solution in toluene was added.

Next, while cooling in an ice bath, 40 ml of a 1.0 mol / triethylaluminum cyclohexane solution was added dropwise. After the addition, the mixture was refluxed at 80 ° C. for 1 hour. The solution was left at −15 ° C. for 24 hours to crystallize. The ratio of barium atoms to aluminum atoms in the obtained crystal was approximately 1: 2.

Preparation of Catalyst Component (c) -1 Using the same apparatus as above, a 1.6 mol / n-butyllithium solution was added dropwise to a 1.0 mol / cyclohexane solution of tetrahydrofurfuryl alcohol while cooling in an ice bath. Thereafter, the concentration was adjusted to 0.5 mol / l of lithium tetrahydrofurfuryl alkoxide.

Polymerization of 1,3-butadiene 120 g of cyclohexane, 1,3
-30 g of butadiene were added. Next, the catalyst component (b) -1 was dissolved in a cyclohexane solution while heating to 70 ° C., and 0.27 mmol was added. Subsequently, 0.81 mmol of the catalyst component (a) -1 was similarly added.

Finally, 0.54 mmol of the catalyst component (c) -1 was added,
The polymerization reaction was performed at 70 ° C. for 90 minutes.

After completion of the reaction, di-t-butyl-p-
0.7 g of cresol is added to 100 g in terms of solid rubber,
After coagulation with methanol, it was dried at 40 ° C. under reduced pressure.

 The polymer yield was 98%.

The microstructure of the polybutadiene obtained is trans-
1,4 bond content 87%, vinyl bond content 4%, cis-1,4
The bond content is 9%, and the crystal melting point [Tm] by DSC is 62%.
It was measured at three points: ° C, 44 ° C, and 33 ° C. DSC of this polymer
The curves are shown in FIG.

Comparative Examples 1-3 Organolithium aluminum compound [catalyst component (a) -1] obtained in Example 1 alone (Comparative Example 1), organic barium aluminum compound [catalyst component (b) -1] alone (comparative Example 2) Using lithium tetrahydrofurfuryl alkoxide [catalyst component (c) -1] alone (Comparative Example 3) in the same amount as in Example 1, and polymerizing 1,3-butadiene in the same manner as in Example 1. I went to. However, no polymer was obtained with any of the catalyst systems.

Comparative Example 4 Using the organobarium aluminum compound [catalyst component (b) -1] obtained in Example 1 and lithium tetrahydrofurfuryl alkoxide [catalyst component (c) -1] in the same manner as in Example 1, The polymerization of 1,3-butadiene was carried out as in Example 1.

 However, no polymer was obtained.

Comparative Example 5 Using the organolithium aluminum compound [catalyst component (a) -1] obtained in Example 1 and lithium tetrahydrofurfuryl alkoxide [catalyst component (c) -1] in the same manner as in Example 1, The polymerization of 1,3-butadiene was carried out as in Example 1.

 The yield of the polymer was 78%.

The microstructure of the polybutadiene obtained is trans-
1,4 bond content 57%, vinyl bond content 16%, cis-1,4
Although the bond content was 27%, the crystal melting point by DSC [Tm]
Was not observed.

Comparative Example 6 According to the method described in JP-A-57-34843, 0.27 mmol of nonylphenoxybarium and 1.08 mmol of triethylaluminum were mixed and aged at 80 ° C. for 1 hour.

30 g of 1,3-butadiene and 120 g of cyclohexane
Was added to the same apparatus as in Example 1 containing
0.81 mmol of -butyllithium and 0.54 mmol of lithium salt of diethylene glycol monoethyl ether were added, and a polymerization reaction was carried out at 70 ° C for 90 minutes.

 The polymer yield was 82%.

The microstructure of the polybutadiene obtained is trans-
1,4 bond content 82%, vinyl bond content 7%, cis-1,4
The bond content was 11%, and the crystal melting point [Tm] by DSC was 15 ° C.

In the method of Comparative Example 6, the same type of catalyst component was used, but the polymer yield and trans-1,4 bond content were lower than those of Example 1.

Comparative Example 7 In the same manner as in Comparative Example 6, 0.27 mmol of nonylphenoxybarium, 1.35 mmol of triethylaluminum, 0.81 mmol of n-butyllithium and 0.81 mmol of diethylene glycol monoethyl ether were used, corresponding to the amounts of the catalyst components used in Example 1. Using 0.54 mmol of lithium salt, 1,3-butadiene was polymerized in the same manner as in Comparative Example 6.

 The polymer yield was 75%.

The microstructure of the polybutadiene obtained is trans-
1,4 bond content 82%, vinyl bond content 7%, cis-1,4
The bond content was 11%, and the crystal melting point [Tm] by DSC was 14 ° C.

Comparative Example 8 Nonylphenoxybarium (0.27 mmol) and n-butyllithium (0.81 mmol) were mixed and aged at 80 ° C. for 1 hour. 30 g of 1,3-butadiene and cyclohexane
The whole amount was added to the same apparatus as in Example 1 containing 120 g, and 70 ° C.
For 2 hours.

 The polymer yield was 83%.

The microstructure of the polybutadiene obtained is trans-
1,4 bond content 45%, vinyl bond content 15%, cis-1,4
Although the bond content was 40%, the crystal melting point by DSC [Tm]
Was not observed.

From the results of Example 1 and Comparative Examples 1 to 8, the catalyst system comprising the components (a) to (c) of the present invention has a specific high trans-1,4 bond content and high activity. I understand.

Cyclohexane same pressure bottle as in Example 1, put 120 g, was added and n- butyllithium 0.81 mmol triethylaluminum 0.81 mmol, LiAl (C ₂ H _5)
3 (n-C ₄ H ₉₎ was synthesized.

Next, in a separate vessel, 0.27 mmol of nonylphenoxybarium and 0.54 mmol of triethylaluminum were aged at 80 ° C. for 1 hour, and Ba [Al (C ₂ H ₅ ) ₃ (OC ₆ H ₄ -C ₉ H ₁₉ )] ₂
Was synthesized and this solution was added. Furthermore, 30 g of 1,3-butadiene was added, and after heating to 70 ° C., 0.54 mmol of lithium tetrahydrofurfuryl alkoxide was added, and a polymerization reaction was carried out for 1 hour.

 The polymer yield was 95%.

The microstructure of the polybutadiene obtained is trans-
1,4 bond content 86%, vinyl bond content 5%, cis-1,4
The bond content is 9% and the crystal melting point [Tm] by DSC is 40%
The temperature was measured at two points, ° C and 27 ° C.

Comparative Example 9 Example 1 was repeated except that 1.70 mmol of nonylphenoxybarium, 6.80 mmol of triethylaluminum, 5.10 mmol of n-butyllithium, and 3.4 mmol of lithium salt of diethylamineethanol were used as catalyst components described in JP-B-57-34843. Similarly, copolymerization of styrene and 1,3-butadiene was performed.

 The copolymer yield was 62%.

Table 1 shows the analysis results of the obtained styrene-butadiene copolymer.

Example 3 A dry reaction vessel having an inner volume of 5 equipped with a stirrer and a jacket was replaced with nitrogen, and 2,000 g of cyclohexane and 500 g of 1,3-butadiene which had been purified and dried in advance were charged.

In a separate vessel, 1.68 mmol of nonylphenoxybarium and 3.36 mmol of triethylaluminum were aged at 80 ° C. for 1 hour to synthesize an ate complex, and this solution was added.

Further, 5.05 mmol of n-butyllithium and 5.05 mmol of triethylaluminum were aged in a separate container at 80 ° C. for 5 minutes to synthesize an ate complex, and this solution was added. Then, 3.36 mmol of a lithium salt of ethylene glycol monophenyl ether was added. Was added and polymerized at 70 ° C. for 90 minutes.

The polymer yield was 92%. Table 1 shows the analysis results of the obtained polybutadiene.

Example 4 In the same manner as in Example 3, 100 g of styrene and 400 g of 1,3-butadiene were charged instead of 1,3-butadiene, and copolymerization was carried out.

 The copolymer yield was 85%.

The analysis results of the obtained styrene-butadiene copolymer are shown in Table 1, and the DSC curve of this copolymer is shown in FIG.

Example 5 In the same manner as in Example 3, 1,3-butadiene was charged.

A solution obtained by aging 1.35 mmol of nonylphenoxybarium and 5.4 mmol of triethylaluminum in a separate container at 80 ° C. for 1 hour, a solution aging 4.05 mmol of n-butyllithium and 4.05 mmol of triethylaluminum in a separate container at 80 ° C. for 5 minutes, and 2.70 mmol of lithium tetrafurfuryl alkoxide was added, and the mixture was polymerized at 70 ° C. for 90 minutes.
The polymer yield was 90%. Table 1 shows the analysis results of the obtained polybutadiene.

Example 6 In the same manner as in Example 3 except that the amount of cyclohexane of Example 3 was increased from 2,000 g to 3,000 g, cyclohexane and 1,3-
Butadiene was charged.

Next, after the temperature of the reaction vessel was raised to 55 ° C., the same amount of polymerization catalyst as in Example 3 was added, and polymerization was started.

Thereafter, the temperature was elevated while stirring at two revolutions per minute without cooling. After 30 minutes, the temperature in the reaction vessel reached 110 ° C, and the polymerization conversion of 1,3-butadiene was 84%. Thereafter, the mixture was left to stir for an additional 30 minutes, and then the polymerization reaction was stopped.

 The polymer yield was 94%.

 Table 1 shows the analysis results of the obtained polybutadiene.

Comparative Example 10 When the same catalyst as in Comparative Example 6 was used to carry out temperature-increasing polymerization in the same manner as in Example 6, the polymer yield was 80%. Table 1 shows the analysis results of the obtained polybutadiene.

Comparing Example 6 with Comparative Example 10, the catalyst system of the present invention in which an ate complex was formed can obtain a polymer having a high trans 1,4 bond content when industrially economically heated polymerization is carried out. You can see that.

If an art complex is not formed, trans-
The 1,4 bond content is low and it is very difficult to control the trans-1,4 bond content.

Examples 7 to 13 Instead of the lithium tetrahydrofurfuryl alkoxide of Example 2, the alkoxides shown in Table 2 were used.
1,3-Butadie was polymerized.

 The polymerization results are shown in Tables 1 to 4 of Table 2.

[Effects of the Invention] The present invention provides (a) an organolithium aluminum compound, (b) an organic barium aluminum compound, (c)
A method of polymerizing a conjugated diene using a catalyst composition containing a predetermined amount of a lithium compound as a polymerization catalyst. A conjugated diene polymer can be easily produced.

[Brief description of the drawings]

FIG. 1 is a DSC curve of the polymer obtained in Example 1, and FIG. 2 is a DSC curve of the copolymer obtained in Example 4.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuhiko Sakakibara 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) C08F 4 / 52 C08F 36/04

Claims (4)

(57) [Claims] 1. The following components (a), (b) and (c)
A method for producing a conjugated diene-based polymer in which a monomer having a conjugated diene as a main component is polymerized in an inert organic solvent using a catalyst composition containing the component. (A) An organic lithium aluminum compound represented by the general formula LiAlR ¹ R ² R ³ R ⁴ (wherein R ^{1 to} R ⁴ are the same or different and represent an alkyl group or an aryl group having 1 to 20 carbon atoms) . (B) General formula Ba (AlR ¹ R ² R ³ R ⁴ ) ₂ or Ba [AlR ¹ R ² R
³ (OR ⁴ )] ₂ (wherein, R ^{1 to} R ⁴ are the same as above). (C) A lithium compound represented by the general formula LiOR ⁵ (wherein, R ⁵ represents an alkyl group or an aryl group having 1 to 20 carbon atoms, or a hydrocarbon group having an oxygen atom and / or a nitrogen atom). 2. The component (c) is represented by a general formula: (Wherein, R ^{1 to} R ³ are the same as above or a hydrogen atom, and n represents an integer of 1 to 3). (Wherein, R ^{1 to} R ⁴ are the same as described above or a hydrogen atom, R ⁶ is the same as R ^{1 to} R ⁴ , and n is the same as described above), and a general formula R ¹ _mN -[(CH ₂ ) _n- OLi] _3-m (wherein, R ¹ and n are the same as above, and m represents an integer of 1 or 2); (Wherein, R ⁷ is an alkylene group having 3 to 10 carbon atoms, and n is the same as described above). (Wherein, R ⁸ and R ⁹ represent an alkylene group having 2 to 5 carbon atoms, and n is the same as described above). (Wherein R ⁸ , R ⁹ and n are the same as described above); (Wherein R ⁸ , R ⁹ and n are as defined above) and a general formula (Wherein, R ¹ and R ² are the same as described above or a hydrogen atom, and n is the same as described above), and is at least one lithium compound selected from the group of compounds represented by the formula: A method for producing a conjugated diene polymer. 3. The process according to claim 1, wherein the conjugated diene is 1,3-butadiene and / or isoprene, and the bound styrene content is 0 to 50% by weight. 4. A catalyst for polymerizing a conjugated diene comprising the catalyst composition according to claim 1.