JP2003342330A - Method for manufacturing diene polymer rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a polymer having a high vinyl content and a narrow molecular weight distribution suitable for use as a tire by copolymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer. <P>SOLUTION: The method for manufacturing the diene polymer rubber comprises polymerizing conjugated diene monomers or a conjugated diene monomer and an aromatic vinyl monomer in the presence of an organic lithium compound represented by the formula: R' (Li)X (wherein R' is an aliphatic or aromatic hydrocarbyl group; and X is an integer of 1-4), a polymerization solvent, tetrahydrofuran in an amount of 0.0053-0.1060 wt.% and ethylene glycol diethyl ether in an amount of 0.02-0.30 wt.%, each amount based on the polymerization solvent, and satisfies the following conditions (1) and (2): (1) The vinyl content of the conjugated diene monomer portion of the diene polymer rubber is at least 60%. (2) The Q value (Mw/Mn) as measured by the HLC of the diene polymer rubber at the time of the end of the polymerization reaction is at most 1.35. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a diene polymer rubber. More specifically, the present invention relates to a method for producing a diene copolymer having a high vinyl content and a narrow molecular weight distribution, preferably a high molecular weight, which is suitable for tire rubber.

[0002]

2. Description of the Related Art In the production of 1,3-butadiene copolymer rubber using an organolithium compound, it is known to control the vinyl content of the butadiene portion by allowing an ether compound such as tetrahydrofuran to exist in the polymerization region. There is. However, in order to obtain a 1,3-butadiene copolymer rubber having a high vinyl content by adding tetrahydrofuran alone, it is necessary to add a large amount, which is extremely economically disadvantageous. Further, in Patent Document 1, a method for controlling the vinyl content by a combined system of two kinds of ether is shown, but it is not always necessary to have a high vinyl content of 1,3-
A butadiene-based copolymer rubber has not been efficiently obtained. In particular, when an attempt is made to obtain a copolymer rubber having a high vinyl content and a high molecular weight, a copolymer having a narrow molecular weight distribution cannot be obtained, which may result in an unfavorable result for tire applications.

[0003]

[Patent Document 1] Japanese Patent Publication No. 5-46365

[0004]

In view of the present situation, the problem to be solved by the present invention is to provide a high vinyl suitable for tires by copolymerizing a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer. It is an object of the present invention to provide a method for producing a polymer having a high content and a narrow molecular weight distribution, more preferably a high molecular weight.

[0005]

That is, according to the present invention, a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer are represented by the formula R '(Li) X (wherein R'is an aliphatic or aromatic hydrocarbon). Group, X is an integer of 1 to 4.)
Polymerization is carried out in the presence of 0.0053 to 0.1060% by weight of tetrahydrofuran and 0.02 to 0.30% by weight of ethylene glycol diethyl ether based on the organolithium compound represented by The present invention relates to a method for producing a diene polymer rubber, which is characterized by the following conditions (1) and (2). (1) The vinyl content of the conjugated diene monomer portion of the diene polymer rubber is 65% or more (2) HLC of the diene polymer rubber at the end of the polymerization reaction
Q value (Mw / Mn) in measurement is 1.35 or less

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The conjugated diene monomer or the conjugated diene monomer and the aromatic vinyl monomer of the present invention are represented by the formula R ′.
0.0053 with respect to the organolithium compound represented by (Li) X (in the formula, R ′ is an aliphatic or aromatic hydrocarbon group and X is an integer of 1 to 4), the polymerization solvent, and the polymerization solvent. ~
0.1060% by weight of tetrahydrofuran and 0.0
A narrow polymer having a vinyl content of 65% or more in the butadiene portion and an Mw / Mn of 1.35 or less in the molecular weight distribution at the end of the polymerization reaction by polymerizing in the presence of 2 to 0.30% by weight of ethylene glycol diethyl ether. Is obtained. Further, as a more preferable method from the viewpoint of resource saving, a method of producing by reducing the amount of ether added can be exemplified. In this case, the addition amount of tetrahydrofuran is 0.
A diene polymer having a desired high vinyl content can be obtained without lowering the vinyl content of the butadiene part by adding ethylene glycol diethyl ether in an amount of 0.04-0.0318% by weight and ethylene glycol diethyl ether in an amount of 0.04-0.16% by weight. In addition, Mw / Mn in the molecular weight distribution at the end of the polymerization reaction can be further narrowed. By this method, a diene polymer having a high vinyl content and a narrow molecular weight distribution, more preferably a high molecular weight, suitable for the tire of the present invention can be obtained. The conjugated diene monomer used in this method is not particularly limited, but 1,3-butadiene, isoprene, 1,3-pentadiene (piperine), 2,3-dimethyl-1,3-butadiene, 1,3
-Hexadiene and the like can be mentioned, and among these, 1,3-butadiene and isoprene are preferable from the viewpoint of the physical properties of the resulting copolymer and the availability in industrial practice.

In the present invention, the vinyl content of the conjugated diene monomer such as 1,3-butadiene is preferably 60% or more, more preferably 65% or more, still more preferably 6%.
It is 8% or more. If the vinyl content is too low, the Tg of the polymer
May become too low, which is not preferable when used as rubber for tires. Further, the higher the vinyl content is, the higher the Tg becomes, and the polymer is suitable for the tire application in which the grip performance is important, which is preferable.

The aromatic vinyl monomer is a compound in which at least one vinyl group is bonded to an aromatic carbon atom, and examples thereof include styrene, 1-vinylnaphthalene, 3-vinyltoluene and divinylbenzene. Among these, styrene having one vinyl group bonded to the benzene nucleus is preferable. Other examples include 3,5-diethyl styrene, 4-n-propyl styrene, 2,4,6-trimethyl styrene, 4-phenyl styrene, 4-p-tolyl styrene, 3,5-diphenyl styrene, 3- Ethyl-1
-Vinylnaphthalene, 8-phenyl-1-vinylnaphthalene and the like can be mentioned.

In the present invention, the aromatic vinyl monomer content can be arbitrarily set, but for example, the styrene content is relatively low S.
It is preferable to obtain a polymer having a t content, for example, 20 to 50%, and more preferably 25 to 40%. When the St content is too low, the Tg of the polymer becomes too low, which may not be preferable when used as a rubber for tires.
On the other hand, if the St content is too high, the solubility in the polymerization solvent may decrease, the amount of ethylene glycol diethyl ether added may be large, and a copolymer having a narrow molecular weight distribution may not be obtained. .

In the present invention, the catalyst of the formula R '(Li) is used as the catalyst.
An organolithium compound represented by x is used. In the formula, X is an integer of 1 to 4 and R'is an aliphatic or aromatic hydrocarbon. The carbon number of R'is not particularly limited and includes high molecular weight compounds. X is 1 out of R '(Li) x,
R'is preferably a hydrocarbon group having 1 to 20 carbon atoms. Suitable R'groups are alkyl, alkenyl, cycloalkyl, aryl, alicaryl or aralkyl and the like, specific examples being methyl, ethyl, n-propyl, isopropyl, n.
-Butyl, isobutyl, sec-butyl, ter-butyl, n-amyl, isoamyl, n-hexyl, 2-ethylhexyl, n-octyl, n-decyl, stearyl, etc .; allyl, n-propenyl, isobutenyl, etc .; 1-cyclo Hexenyl, cyclohexyl, cyclohexyl ethal, etc .; phenyl, naphthyl, etc., tolyl, butylphenyl, ethylnaphthyl, etc .; benzyl, phenylbutyl, etc. Further, the number of carbon atoms in the formula R ′ is 2 to 40, and X is 2
Compounds such as ~ 4 are also included in the organolithium compounds of the present invention. For example, tetramethylenedilithium, pentamethylenedilithium, hexamethylenedilithium, diphenylethylenedilithium, 1,5-dilithiumnaphthalene, 1,20-dilithioeicosane, 1,4-dilithiocyclohexane and the like can be mentioned. . It is also possible to use an organolithium compound containing a functional group containing a hetero atom that does not adversely affect the polymerization. Further, an organomonolithium compound having a hydrocarbon residue containing 40 or more carbon atoms or a dilithium compound is also included in the organolithium compound of the present invention, but a low molecular weight or high molecular weight linear heavy compound is preferable. An organolithium compound in which one end or both ends of the combination is lithium, and among these, particularly preferred are polystyryl monolithium, polybutadienyl monolithium, polyisoprenyl monolithium, polystyrene dilithium, and polybutadiene. Enildilithium,
Examples thereof include polyisoprenyldilithium and linear copolymers of styrene and butadiene, which have lithium at one or both ends. Two or more kinds of the above lithium compounds may be used. Among the above lithium compounds, alkyl lithium in which the alkyl group has 2 to 8 carbon atoms is preferable, and n-butyl lithium is particularly preferable.

It is well known that increasing the amount of the organolithium compound in the polymerization reaction increases the polymerization rate and decreases the molecular weight, but this characteristic is also observed in the method of the present invention using tetrahydrofuran and ethylene glycol diethyl ether. It will not be lost. Therefore, the amount of the organolithium compound can be varied over a wide range depending on the purpose of the polymerization or the method of polymerization.
The amount is in the range of 0.05 to 100 millimoles, but in the case of obtaining a high molecular weight polymer with high activity, the range of 0.1 to 10 millimoles is used. If it is too small, only a low molecular weight polymer is obtained, and if it is too small, it becomes an ultra high molecular weight copolymer, which may deteriorate the kneading processability.

In the present invention, the polymerization solvent is a fat such as propane, butane, pentane, hexane, heptane, isooctane, cyclopentane, cyclohexane, decane, hexadecane, benzene, toluene, ethylbenzene, xylenes, naphthalene, tetrahydronaphthalene, etc. Group or aromatic hydrocarbons are used. Two kinds of these polymerization solvents may be used in combination. The amount of the polymerization solvent used for the polymerization is determined by the desired molecular weight of the polymer, the type of the polymerization solvent, etc.
It is in the range of 0 to 2000 parts by weight, preferably 300 to 1000 parts by weight. If necessary, the reaction system can be maintained at an appropriate viscosity by adding a polymerization solvent during the polymerization reaction. If the amount of the polymerization solvent is too small, the solution viscosity may increase, and a homogenous polymer having a narrow molecular weight distribution may not be obtained. It requires a large amount of energy, which is not preferable from the industrial and energy saving viewpoints. In the present invention, tetrahydrofuran and ethylene glycol diethyl ether are used as a vinyl content control agent system. Tetrahydrofuran is used in an amount of 0.0053 to 0.1060 with respect to the polymerization solvent.
% By weight, preferably 0.0053 to 0.0742% by weight
Is. More preferably, it is 0.0053 to 0.0640% by weight. If the amount added is too small, the polymerization rate will decrease and the randomness of the polymer will decrease, which may not be preferable as a rubber for tires. If the amount added is too large, a large amount of ethylene glycol diethyl ether is required to obtain a polymer having a high vinyl content, and a copolymer having a high vinyl content may not be substantially obtained. The content of ethylene glycol diethyl ether is 0.02 to 0.30% by weight, preferably 0.04 to 0.30% by weight, and more preferably 0.04 to 0.20. If the amount added is small, a polymer having a high vinyl content may not be obtained, and if the amount added is too large, a copolymer having a narrow molecular weight distribution may not be obtained. Further, in order to produce a high vinyl content polymer with a small amount of ether added and a narrow molecular weight distribution, preferably a high molecular weight diene polymer, tetrahydrofuran is added in an amount of 0.0053 to 0.0318% by weight and ethylene glycol. A method of adding 0.04 to 0.16% by weight of diethyl ether is preferable. In addition, ethylene glycol dibutyl ether and TME are generally used to adjust the vinyl content.
A method using DA (N, N, N ', N'-tetramethylethylenediamine) or the like is known, but when these are used, a high vinyl content cannot be achieved, or a high vinyl content can be achieved. However, there are disadvantages such as not having a narrow molecular weight distribution and deterioration of living property, and it is substantially difficult to produce a polymer having a high vinyl content and a narrow molecular weight distribution, preferably a high molecular weight, which is the object of the present invention.

The polymerization method of the present invention uses the monomer, catalyst, polymerization solvent and vinyl content control agent described in detail above, and the solution polymerization method is preferably used as the polymerization method. The polymerization method of the present invention can be carried out batchwise or continuously by using an appropriate addition method of raw materials. The catalyst, the vinyl content control agent, the polymerization solvent, and the monomer may be added to the reactor at the same time, or the vinyl content control agent may be added after the addition of the polymerization solvent and the monomer, and various addition methods are possible.

Further, the polymerization can be continuously carried out by maintaining the concentration of the reactant in the reactor at a predetermined value by the above-mentioned various addition methods or the like for an appropriate residence time. The polymerization time in the batch method is not particularly limited, but almost complete when the catalyst amount is at least 24 hours. In the continuous method, the residence time varies widely depending on the conditions, but is generally several tens of minutes to 2 hours.
The polymerization temperature is not particularly limited, but is usually -80 to 150 ° C.
And 0 to 80 ° C is preferable. In the batch system, the temperature may be raised continuously or in multiple stages, and in the continuous system, the temperature may be raised at the final stage of the polymerization. The polymerization reaction can be carried out under any pressure, but it is usually desirable to carry out the polymerization at a pressure sufficient to keep the monomer substantially liquid. Generally, pressure depends on the monomer, polymerization solvent, and polymerization temperature. Further, after the polymerization is completed, the coupling reaction can be carried out using a coupling agent such as silicon tetrachloride or tin tetrachloride.

Generally, when used for tire applications, the Q value (M of the polymer after completion of the polymerization reaction (before the coupling reaction) (M
It is preferable that w / Mn) is small and the molecular weight is large, and it is preferable from the viewpoint of physical properties that the Q value after the coupling reaction is also small and the molecular weight is increased. Specifically, the Q value before coupling is 1.35 or less, preferably 1.30.
And more preferably 1.25 or less. The Q value after coupling is 2.2 or less, and the smaller the Q value, preferably 2.1, the better the tire performance. Further, it is preferable to perform the coupling from the viewpoint of roll processability. The molecular weight before the coupling reaction is 2 as Mw.
It is preferably at least 0,000, more preferably at least 500,000, further preferably at least 700,000. The molecular weight after the coupling reaction is Mw.
Is preferably 600,000 or more, more preferably 1.1 million or more, and further preferably 1.2 million or more. The higher the molecular weight, the higher the modulus and the more excellent the abrasion resistance of the polymer. On the other hand, if the molecular weight is too high, the kneading processability in a Banbury mixer may deteriorate, and in that case, it is preferable to add 30 phr or more of oil, more preferably 40 phr or more, and further 50 phr.
It is desirable to add the above oils. By adding this oil, there is no concern about kneading processability, and a polymer having a molecular weight after coupling, which is preferable for physical properties, of 1.3 million or more, and even 1.7 million or more can be effectively used. The oil is not particularly limited as long as it is an oil generally used for rubber applications, but from the viewpoint of cost, aromatic oil is often used.

Generally, it is preferred to remove water, oxygen, carbon dioxide and other catalyst deactivating substances from all substances involved in the polymerization process such as catalyst components, vinyl content control agents, polymerization solvents, monomers and the like. The polymerization reaction may also be performed in an atmosphere of an inert gas such as dry nitrogen or argon.

After the polymerization is completed or after the desired molecular weight is reached or after the subsequent coupling reaction, the polymer can be recovered by a usual post-treatment method. For example, the polymer can be recovered by performing operations such as antioxidation, catalyst deactivation, polymer separation, recovery, and drying. That is, an antioxidant is added to the polymerization solution, and then a catalyst deactivator such as methyl alcohol, isopropyl alcohol, and water is added to deactivate the catalyst,
The polymer can be recovered, or the polymerization solution containing an antioxidant can be injected into a superheated non-hydrocarbon diluent such as hot water, or in some cases the polymerization solvent and unreacted monomer mixture. The polymer can be separated by distilling off. Further, the catalyst may be a very small amount, and is generally a high boiling point compound, and since it is possible to easily complete the polymerization almost completely, it is not necessary to remove the catalyst and a low boiling point aliphatic hydrocarbon often used as a preferable solvent such as n. -It is often necessary to focus only on the removal of hexane, so if an antioxidant such as phenyl-β-naphthylamine is added to this polymerization solution, a small amount of a catalyst deactivator is further added, By heating this solution directly and, if necessary, using a decompression operation, the polymerization solvent can be removed and at the same time a dry polymer can be obtained.
Since a small amount of the catalyst is sufficient, there is often no problem in terms of physical properties even if it remains in the polymer, but when it is required to reduce the catalyst residue to a low level, since the catalyst itself is a homogeneous system, The object can be easily achieved by a method of selecting an appropriate medium and washing. Of course, reprecipitation may also be used to purify the polymer. The vinyl content in the rubbery or resinous polymer obtained as described above can be controlled by the weight concentration of the vinyl content control agent in the polymerization solvent and the polymerization temperature. The vinyl content of the butadiene part of the copolymer can be as high as 75% or even higher if desired. At that time, the temperature may be lowered in order to increase the vinyl content or the weight concentration of the vinyl content control agent with respect to the polymerization solvent may be increased. In the copolymer in this process, if the composition of both monomers is properly taken, a polymer and a rubber-like solid copolymer without gel content can be obtained, and the molecular weight of the copolymer depends on the ratio of the monomer and the organolithium compound. It is possible to decide.

[0018]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 A stainless steel polymerization reaction container having an internal volume of 5 liters was washed,
After drying and replacing with dry nitrogen, 1,3-butadiene 2
07g, styrene 93g, tetrahydrofuran 1.35
g, hexane 2.55 kg, and ethylene glycol diethyl ether 5.1 g were charged into a stainless steel polymerization reaction container, the internal temperature was stabilized at 30 ° C., and then n-butyllithium solution of n-butyllithium as a polymerization initiator 2. 5 mmol
Was added, and 138 g of 1,3-butadiene / 123 with stirring
0 minutes, styrene 62g / 90 minutes continuously added, 6
Polymerization was carried out at 0 ° C. for 3 hours. After the completion of the polymerization, 0.375 mmol of silicon tetrachloride as a coupling agent was added,
After the minute stirring, 10 ml of methanol was added, and the mixture was further stirred for 5 minutes. Then, take out the contents of the polymerization reaction container,
After adding 2.5 g of 2,6-di-t-butyl-p-cresol (Sumitomo Chemical's Sumilizer BHT) and evaporating most of the hexane, the mixture was dried under reduced pressure at 55 ° C for 12 hours to obtain a polymer rubber. Got

Example 2 The same procedure as in Example 1 was repeated except that 2.55 g of ethylene glycol diethyl ether was added.

Example 3 A stainless steel polymerization reaction vessel having an internal volume of 20 liters was washed, dried, and purged with dry nitrogen, and then 621 g of 1,3-butadiene, 279 g of styrene, 5.4 g of tetrahydrofuran, 10.2 kg of hexane, and ethylene glycol. After charging 20.4 g of diethyl ether into a stainless steel polymerization reaction container and stabilizing the internal temperature at 30 ° C., n-butyllithium n-hexane solution 3.0 as a polymerization initiator was added.
mmol, 1,3-butadiene 414 with stirring
g / 135 minutes and styrene 186 g / 105 minutes were continuously added, and polymerization was carried out at 60 ° C. for 3 hours. After completion of polymerization,
After adding 0.25 mmol of silicon tetrachloride as a coupling agent and stirring for 30 minutes, 10 ml of methanol was added and further stirred for 5 minutes. After that, the contents of the polymerization reaction container were taken out, 7.5 g of 2,6-di-t-butyl-p-cresol (Sumilyzer BHT manufactured by Sumitomo Chemical Co., Ltd.) was added to evaporate most of hexane, and then 55 It was dried under reduced pressure at ℃ for 12 hours to obtain a polymer rubber.

Example 4 A polymerization reactor made of stainless steel having an internal volume of 20 liters was washed, dried, and purged with dry nitrogen, and then 621 g of 1,3-butadiene, 279 g of styrene, 5.4 g of tetrahydrofuran, 10.2 kg of hexane, and ethylene glycol. 19.38 g of diethyl ether was charged into a stainless steel polymerization reaction container, the internal temperature was stabilized at 30 ° C., and n-hexane solution of n-butyllithium as a polymerization initiator was then 2.9.
mmol, 1,3-butadiene 414 with stirring
g / 135 minutes and styrene 186 g / 105 minutes were continuously added, and polymerization was carried out at 60 ° C. for 3 hours. After completion of polymerization,
After adding 0.25 mmol of silicon tetrachloride as a coupling agent and stirring for 30 minutes, 10 ml of methanol was added and further stirred for 5 minutes. Then, the contents of the polymerization reaction vessel were taken out, 2.5 g of 2,6-di-t-butyl-p-cresol (Sumitizer Chemical's Sumilizer BHT) was added to evaporate most of hexane, and then 55 It was dried under reduced pressure at ℃ for 12 hours to obtain a polymer rubber.

Example 5 A stainless steel polymerization reaction vessel having an internal volume of 20 liters was washed, dried, and purged with dry nitrogen, and then 585 g of 1,3-butadiene, 315 g of styrene, 5.4 g of tetrahydrofuran, 10.2 kg of hexane, and ethylene glycol. 1.36 g of diethyl ether was charged into a stainless steel polymerization reaction vessel, the internal temperature was stabilized at 30 ° C., and then n-butyllithium solution of n-butyllithium as a polymerization initiator 2.
6 mmol was added and 1,3-butadiene 39 was added with stirring.
0 g / 135 minutes and 210 g / 105 minutes of styrene were continuously added, and polymerization was carried out at 60 ° C. for 3 hours. After completion of polymerization, 0.26 mmol of silicon tetrachloride as a coupling agent
Was added and stirred for 30 minutes, 10 ml of methanol was added, and the mixture was further stirred for 5 minutes. The subsequent process was the same as that of Example 4.

Example 6 A polymerization reactor made of stainless steel having an internal volume of 20 liters was washed, dried, and purged with dry nitrogen, and then 621 g of 1,3-butadiene, 279 g of styrene, 3.24 g of tetrahydrofuran, 10.2 kg of hexane, and ethylene glycol. After charging 16.32 g of diethyl ether into a stainless steel polymerization reaction vessel and stabilizing the internal temperature at 30 ° C., 3.0 mmol of n-hexane solution of n-butyllithium as a polymerization initiator was added, and the mixture was stirred at 1 , Butadiene of 414 g / 135 minutes and styrene of 186 g / 105 minutes were continuously added, and polymerization was carried out at 60 ° C. for 3 hours. After completion of polymerization, silicon tetrachloride as a coupling agent 0.345 mm
was added and stirred for 30 minutes, 10 ml of methanol was added, and the mixture was further stirred for 5 minutes. The subsequent processing is the same as in Example 4.
The same process was performed.

Example 7 A stainless steel polymerization reaction vessel having an internal volume of 20 liters was washed, dried, and purged with dry nitrogen, and then 621 g of 1,3-butadiene, 279 g of styrene, 1.08 g of tetrahydrofuran, 10.2 kg of hexane, and ethylene glycol. 13.26 g of diethyl ether was charged into a stainless steel polymerization reaction vessel, the internal temperature was stabilized at 30 ° C., and then 3.0 mmol of n-hexane solution of n-butyllithium as a polymerization initiator was added, and the mixture was stirred to 1 , Butadiene of 414 g / 135 minutes and styrene of 186 g / 105 minutes were continuously added, and polymerization was carried out at 60 ° C. for 3 hours. After completion of polymerization, silicon tetrachloride as a coupling agent 0.345 mm
was added and stirred for 30 minutes, 10 ml of methanol was added, and the mixture was further stirred for 5 minutes. The subsequent processing is the same as in Example 4.
The same process was performed.

Comparative Example 1 A polymerization reactor made of stainless steel having an internal volume of 5 liters was washed,
After drying and replacing with dry nitrogen, 1,3-butadiene 2
07g, styrene 93g, tetrahydrofuran 1.35
g, hexane 2.55 kg, and diethylene glycol diethyl ether 2.55 g were charged in a stainless steel polymerization reaction container, and after stabilizing the internal temperature at 30 ° C., n-hexane solution of n-butyllithium as a polymerization initiator 2.5 mm
ol was added, and with stirring, 138 g of 1,3-butadiene /
120 minutes and 62 g / 90 minutes of styrene were continuously added, and polymerization was carried out at 60 ° C. for 3 hours. After completion of the polymerization, 0.375 mmol of silicon tetrachloride as a coupling agent was added, and after stirring for 30 minutes, the same treatment as in Example 1 was performed.

Comparative Example 2 A polymerization reactor made of stainless steel having an internal volume of 5 liters was washed,
After drying and replacing with dry nitrogen, 1,3-butadiene 2
07g, styrene 93g, tetrahydrofuran 1.35
g, hexane 2.55 kg, TMEDA (N, N,
5.1 g of N ′, N′-tetramethylethylenediamine) was charged into a stainless steel polymerization reaction container, the internal temperature was stabilized at 30 ° C., and then 2.5 mmol of n-hexane solution of n-butyllithium as a polymerization initiator. Was added, and 138 g of 1,3-butadiene and 120 minutes of styrene were added with stirring.
It was continuously added at a rate of g / 90 minutes, and polymerized at 60 ° C. for 3 hours. After completion of the polymerization, 0.375 mmol of silicon tetrachloride as a coupling agent was added, and after stirring for 30 minutes, the same treatment as in Example 1 was performed.

The polymer rubbers obtained in Examples 1 to 7 and Comparative Examples 1 and 2 were measured and evaluated as follows. Vinyl Content of Polymer Rubber Determined by infrared spectroscopy. Styrene content of polymer rubber It was measured by a refractive index method. Molecular weight and molecular weight distribution of polymer rubber HLC-8120 GPC (manufactured by Tosoh) A solution of 0.1 g of polymer dissolved in 20 ml of tetrahydrofuran was subjected to a column at 40 ° C (Tosoh column: TSKgel SuperHM-
H series 2), UV spectrometer (Tosoh UV-8020)
And the molecular weight (standard polystyrene conversion) and the molecular weight distribution were measured.

The measurement results are shown in Tables 1 and 2.

[0030]

[Table 1] Vinyl content control agent A: ethylene glycol diethyl ether B: diethylene glycol diethyl ether C: N, N, N ′, N′-tetramethylethylenediamine

[0031]

[Table 2] Vinyl content control agent A: ethylene glycol diethyl ether

[0032]

As described above, according to the present invention, a conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer are copolymerized to obtain a high vinyl content and a narrow molecular weight distribution suitable for tire applications, and more preferably a high molecular weight. It was possible to provide a method for producing the polymer.

Continued front page    F-term (reference) 4J015 DA02 EA00                 4J100 AB00Q AB02Q AB04Q AB07Q                       AB16Q AS01P AS02P AS03P                       AS04P BC43Q CA04 CA31                       DA04 FA08 FA19 FA30 HA55                       HB29 HD07 HE14

Claims (4)

[Claims] 1. A conjugated diene monomer or a conjugated diene monomer and an aromatic vinyl monomer are represented by the formula R ′ (Li) X.
(In the formula, R ′ is an aliphatic or aromatic hydrocarbon group, and X is 1
Is an integer of ~ 4. ) An organolithium compound represented by
0.0053 to 0.10 with respect to the polymerization solvent and the polymerization solvent
60 wt% tetrahydrofuran and 0.02-0.
Polymerization is performed in the presence of 30% by weight of ethylene glycol diethyl ether, and the following (1) to
A method for producing a diene polymer rubber that satisfies the condition (2). (1) The vinyl content of the conjugated diene monomer portion of the diene polymer rubber is 60% or more (2) HLC of the diene polymer rubber at the end of the polymerization reaction
Q value (Mw / Mn) in measurement is 1.35 or less 2. A conjugated diene monomer and an aromatic vinyl monomer are represented by the formula R ′ (Li) X (wherein R ′ is an aliphatic or aromatic hydrocarbon group, and X is an integer of 1 to 4). Polymerization is performed in the presence of 0.0053 to 0.0742% by weight of tetrahydrofuran and 0.02 to 0.20% by weight of ethylene glycol diethyl ether with respect to the organolithium compound represented by A method for producing a diene polymer rubber, which is characterized in that it also satisfies the following conditions (1) to (3). (1) The vinyl content of the conjugated diene monomer portion of the diene polymer rubber is 65% or more and the St content is 20% to 50%. (2) HLC of the diene polymer rubber at the end of the polymerization reaction.
The Q value (Mw / Mn) in the measurement is 1.30 or less (3) The Q value (Mw / Mn) in the HLC measurement of the diene polymer rubber after the completion of the coupling reaction is 2.2 or less, and Mw is over 600,000 3. The diene polymer rubber according to claim 2, which satisfies the following conditions (1) to (4). (1) The vinyl content of the conjugated diene monomer portion of the diene polymer rubber is 65% or more and the St content is 25% to 40% (2) HLC of the diene polymer rubber at the end of the polymerization reaction
The Q value (Mw / Mn) in the measurement is 1.30 or less (3) The Q value (Mw / Mn) in the HLC measurement of the diene polymer rubber after the completion of the coupling reaction is 2.1 or less, and Mw is over 1.1 million (4) Oil extension is over 40 phr 4. The method for producing a diene polymer rubber according to claim 2, which satisfies the following conditions (1) to (4). (1) The vinyl content of the conjugated diene monomer portion of the diene polymer rubber is 65% or more and the St content is 25% to 40% (2) HLC of the diene polymer rubber at the end of the polymerization reaction
The Q value (Mw / Mn) in the measurement is 1.30 or less (3) The Q value (Mw / Mn) in the HLC measurement of the diene polymer rubber after the completion of the coupling reaction is 2.1 or less, and Mw is over 1.1 million (4) Oil extension is over 40 phr