JP2010163542A - Method for producing polymerization catalyst for conjugated diene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a conjugated diene polymer having a high cis-1,4 structure content using a catalyst that is relatively easy to handle and highly active.
In a method for producing a catalyst for conjugated diene polymerization comprising (A) an yttrium compound, (B) an ionic compound comprising a non-coordinating anion and a cation, and (C) an organoaluminum compound, ) Component and (C) component are mixed and aged at less than 50 ° C. for 5 to 300 minutes, and then the component (B) is added.
[Selection figure] None

Description

  The present invention relates to a method for producing a conjugated diene polymerization catalyst containing an yttrium compound.

  Many proposals have been made on polymerization catalysts for conjugated dienes such as 1,3-butadiene and isoprene, some of which have been industrialized. For example, for the production of a conjugated diene polymer having a high cis-1,4 structure content, a catalyst obtained by combining a transition metal compound such as titanium, cobalt, nickel, neodymium, etc., and organoaluminum is often used.

  Polymerization of conjugated dienes using a Group 3 element of the periodic table as a catalyst is known, and various polymerization methods have been proposed so far. For example, Japanese Patent Laid-Open No. 7-268013 (Patent Document 1) discloses a catalyst system comprising a rare earth metal salt, an organometallic compound of Group I to III elements of the periodic table, and a fluorine-containing organoboron compound. . JP-A-11-80222 (Patent Document 2) discloses compounds of Group IIIB metals of the periodic table, ionic compounds of non-coordinating anions and cations, and elements I to III of the periodic table. A polymerization catalyst comprising an organometallic compound is disclosed.

  As a polymerization catalyst using an yttrium compound, International Publication No. 2006/049016 pamphlet (Patent Document 3) discloses a catalyst system using a yttrium compound having a bulky substituent, and Japanese Patent Application Laid-Open No. 2007-161918. The publication (Patent Document 4) discloses a catalyst system using an yttrium compound having bis (trimethylsilyl) amide as a ligand. The cis-1,4 structure content of the conjugated diene polymers obtained with these catalyst systems is generally about 97-98.5%.

  As a catalyst system for obtaining a conjugated diene polymer having a very high cis-1,4 structure content, JP-A-2002-256612 (Patent Document 5), JP-A-2004-027179 (Patent Document 6), etc. Those containing a metallocene-type cation complex of a rare earth metal compound are disclosed. However, metallocene type complexes are difficult to synthesize and isolate, and are also very sensitive to air, water, etc., and thus are difficult to handle. Furthermore, there is a problem that a conjugated diene polymer having a very high cis-1,4 structure content can be obtained only at a low polymerization temperature.

JP-A-7-70143 Japanese Patent Laid-Open No. 7-268013 International Publication No. 2006/049016 Pamphlet JP 2007-161918 A Japanese Patent Laid-Open No. 2002-256012 Japanese Patent Laid-Open No. 2004-027179

  An object of the present invention is to provide a method for producing a conjugated diene polymer having a high cis-1,4 structure content by using a catalyst containing a highly active yttrium compound that is relatively easy to handle.

  The present invention relates to a method for producing a catalyst for conjugated diene polymerization comprising (A) an yttrium compound, (B) an ionic compound comprising a non-coordinating anion and a cation, and (C) an organoaluminum compound. A method for producing a catalyst for conjugated diene polymerization, wherein the component and the component (C) are mixed and aged at a temperature lower than 50 ° C. for 5 to 300 minutes, and then the component (B) is added.

  The yttrium compound is preferably an yttrium compound represented by the following general formula.

（Ｒ_１，Ｒ_２，Ｒ_３は水素、または炭素数１〜１２の置換基を表し、Ｏは酸素原子を表し、Ｙはイットリウム原子を表す。）

_{(R 1, R 2, R} 3 represents hydrogen, or a substituent having 1 to 12 carbon atoms, O represents an oxygen atom, Y represents yttrium atom.)

  Further, the present invention is a conjugated diene polymerization catalyst obtained by the above method, and a method for producing a conjugated diene polymer using the catalyst.

  By using the catalyst obtained in the present invention, a conjugated diene polymer having a high cis-1,4 structure content can be produced with high efficiency.

  Examples of the yttrium compound as the component (A) of the catalyst system include yttrium trichloride, yttrium tribromide, yttrium triiodide, yttrium nitrate, yttrium sulfate, yttrium trifluoromethanesulfonate, yttrium acetate, yttrium trifluoroacetate, and malon. Yttrium salts such as yttrium acid, octyl acid (ethylhexanoate), yttrium naphthenate, yttrium versatic acid, yttrium neodecanoate, yttrium trimethoxide, yttrium triethoxide, yttrium triisopropoxide, yttrium tributoxide, yttrium Alkoxides such as triphenoxide, trisacetylacetonatoyttrium, tris (hexanedionato) yttrium, tris (heptane) Onato) Yttrium, Tris (dimethylheptanedionato) yttrium, Tris (tetramethylheptanedionato) yttrium, Trisacetoacetatoytrium, Cyclopentadienyl yttrium dichloride, Dicyclopentadienyl yttrium chloride, Tricyclopentadienyl yttrium Organic yttrium compounds such as yttrium salt pyridine complex, organic base complexes such as yttrium salt picoline complex, yttrium salt hydrate, yttrium salt alcohol complex and the like. Particularly preferred is an yttrium complex represented by the following general formula.

（Ｒ_１，Ｒ_２，Ｒ_３は水素、または炭素数１〜１２の置換基を表し、Ｏは酸素原子を表し、Ｙはイットリウム原子を表す。）

_{(R 1, R 2, R} 3 represents hydrogen, or a substituent having 1 to 12 carbon atoms, O represents an oxygen atom, Y represents yttrium atom.)

  Specific examples of the substituent having 1 to 12 carbon atoms include methyl group, ethyl group, vinyl group, n-propyl group, isopropyl group, 1-propenyl group, allyl group, n-butyl group, and s-butyl group. , Isobutyl group, t-butyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethyl Examples include propyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, cyclohexyl group, methylcyclohexyl group, ethylcyclohexyl group, phenyl group, benzyl group, toluyl group, and phenethyl group. . Further, those in which a hydroxyl group, a carboxyl group, a carbomethoxy group, a carboethoxy group, an amide group, an amino group, an alkoxy group, a phenoxy group and the like are substituted at an arbitrary position are also included.

  Examples of the yttrium compounds represented by the above general formula include tris (acetylacetonato) yttrium, tris (hexanedionato) yttrium, tris (heptanedionato) yttrium, tris (dimethylheptanedionato) yttrium, tris (trimethylheptanedionato) ) Yttrium, tris (tetramethylheptanedionato) yttrium, tris (pentamethylheptanedionato) yttrium, tris (hexamethylheptanedionato) yttrium, trisacetoacetatoyttrium and the like.

  As the ionic compound composed of the non-coordinating anion and cation, which is the component (B) of the catalyst system, a combination of any arbitrarily selected from known non-coordinating anions and cations may be used. it can.

  Examples of non-coordinating anions include tetra (phenyl) borate, tetra (fluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) ) Borate, tetrakis (pentafluorophenyl) borate, tetrakis (3,5-bistrifluoromethylphenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetra (toluyl) borate, tetra (Xylyl) borate, triphenyl (pentafluorophenyl) borate, tris (pentafluorophenyl) (phenyl) borate, tridecahydride-7,8-dicarboundeborate, tetrafluoroborate And hexafluorophosphate Kill.

  On the other hand, examples of the cation include a carbonium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation.

  Specific examples of the carbonium cation include trisubstituted carbonium cations such as triphenylcarbonium cation and trisubstituted phenylcarbonium cation. Specific examples of the tri-substituted phenyl carbonium cation include tri (methylphenyl) carbonium cation and tri (dimethylphenyl) carbonium cation.

  Specific examples of the ammonium cation include a trialkylammonium cation, a triethylammonium cation, a tripropylammonium cation, a tributylammonium cation, a trialkylammonium cation such as a tri (n-butyl) ammonium cation, an N, N-dimethylanilinium cation, an N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation and other N, N-dialkylanilinium cation, di (i-propyl) ammonium cation, dicyclohexylammonium cation and other dialkylammonium cations Can be mentioned.

  Specific examples of phosphonium cations include triphenylphosphonium cation, tetraphenylphosphonium cation, tri (methylphenyl) phosphonium cation, tetra (methylphenyl) phosphonium cation, tri (dimethylphenyl) phosphonium cation, tetra (dimethylphenyl) phosphonium cation, etc. Mention may be made of arylphosphonium cations.

  A preferred non-coordinating anion and cation combination is a boron-containing compound and a carbocation. Specific examples of the ionic compound include triphenylcarbonium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (fluoro). Phenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, 1,1'-dimethylferrocenium tetrakis (pentafluorophenyl) borate and the like. These ionic compounds may be used alone or in combination of two or more.

  Moreover, an aluminoxane can also be used instead of the ionic compound which consists of the non-coordinating anion and cation which are (B) components. The aluminoxane is obtained by bringing an organoaluminum compound into contact with a condensing agent, and examples thereof include a chain aluminoxane represented by the general formula (—Al (R ′) O—) n or a cyclic aluminoxane. (R ′ is a hydrocarbon group having 1 to 10 carbon atoms, including those partially substituted with a halogen atom and / or an alkoxy group. N is the degree of polymerization and is 5 or more, preferably 10 or more) . Examples of R ′ include methyl, ethyl, propyl, and isobutyl groups, with a methyl group being preferred. Examples of the organoaluminum compound used as an aluminoxane raw material include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, and mixtures thereof.

  Among these, aluminoxane using a mixture of trimethylaluminum and tributylaluminum as a raw material can be preferably used.

  A typical example of the condensing agent is water, but other than the above, an arbitrary one in which trialkylaluminum undergoes a condensation reaction, for example, adsorbed water such as an inorganic substance, diol, and the like can be given.

  Examples of organoaluminum compounds that are the component (C) of the catalyst system include trialkylaluminum, organoaluminum halogen compounds such as dialkylaluminum chloride, dialkylaluminum bromide, alkylaluminum sesquichloride, alkylaluminum sesquibromide, alkylaluminum dichloride, Examples thereof include organic aluminum hydride compounds such as dialkylaluminum hydrides.

  Specific examples of the trialkylaluminum include trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, and tridecylaluminum.

  Specific examples of organoaluminum halogen compounds include dialkylaluminum chlorides such as dimethylaluminum chloride and diethylaluminum chloride, ethylaluminum sesquichloride, and ethylaluminum dichloride. Specific examples of hydrogenated organoaluminum compounds include diethylaluminum hydride and diisobutyl. Examples thereof include aluminum hydride and ethylaluminum sesquihydride.

  These organoaluminum compounds may be used alone or in combination of two or more.

  The amount of the catalyst components (A) to (C) and the ratio between them are adjusted as necessary so that the resulting polymer has the desired physical properties. Usually, the amount of the component (A) is preferably 0.0001 to 0.5 mmol, particularly preferably 0.0005 to 0.1, based on 100 g of the conjugated diene monomer. The molar ratio (A) / (B) between the component (A) and the component (B) is preferably 1 / 1.0 to 1 / 5.0, particularly preferably 1 / 1.0 to 1 / 3.0. The molar ratio (A) / (C) between the component (A) and the component (C) is preferably 1/1 to 1/5000, particularly preferably 1/10 to 1/2000.

  In the present invention, first, (A) an yttrium compound and (C) an organoaluminum compound are mixed and aged (reacted) at a predetermined temperature for a predetermined time. Thereafter, (B) an ionic compound composed of a non-coordinating anion and a cation is added to form a catalyst. These catalyst components can be mixed in the presence or absence of the conjugated diene to be polymerized.

  The aging temperature of the component (A) and the component (C) may be less than 50 ° C, but 0 ° C or more is preferable. A more preferable temperature range is 10 to 45 ° C, and 20 to 40 ° C is particularly preferable. The aging time is 5 to 300 minutes, preferably 10 to 240 minutes, and particularly preferably 15 to 180 minutes.

  The catalyst obtained as described above can be used by being supported on an inorganic compound or an organic polymer compound.

  There is no limitation on the polymerization solvent, for example, aliphatic hydrocarbons such as butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, Olefin compounds such as olefin compounds and cis-2-butene and trans-2-butene can be used. In particular, benzene, toluene, cyclohexane, or a mixture of cis-2-butene and trans-2-butene is preferable. In addition, bulk polymerization (bulk polymerization) using the monomer itself as a polymerization solvent can also be performed.

  The concentration of the conjugated diene monomer in the solution polymerization is preferably 5 to 70% by weight, particularly preferably 10 to 50% by weight.

  The polymerization temperature is preferably in the range of -30 to 150 ° C, particularly preferably in the range of 0 to 100 ° C. The polymerization time is preferably in the range of 1 minute to 12 hours, particularly preferably 5 minutes to 5 hours.

  Examples of conjugated dienes that can be polymerized include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene (piperylene). 1,3-hexadiene, 1,3-cyclohexadiene, and the like. These may be used alone or in combination of two or more to obtain a copolymer. 1,3-butadiene or isoprene is preferred.

  When polymerizing a conjugated diene, hydrogen, a metal hydride compound, or a hydrogenated organometallic compound can be used as a molecular weight regulator, but it is particularly preferable to adjust the molecular weight using hydrogen.

  After performing the polymerization for a predetermined time, the inside of the polymerization tank is released as necessary, and post-treatment such as washing and drying steps is performed.

  Examples according to the present invention will be specifically described below. The polymerization conditions and polymerization results are summarized in Tables 1 and 2.

The microstructure was performed by infrared absorption spectrum analysis. The microstructure was calculated from the absorption intensity ratio of cis 740 cm ⁻¹ , trans 967 cm ⁻¹ and vinyl 910 cm ⁻¹ .

  The molecular weight and molecular weight distribution were evaluated by the weight average molecular weight Mw determined from GPC using polystyrene as a standard substance, and the ratio Mw / Mn of Mw and number average molecular weight Mn.

Example 1
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Then, hydrogen gas 0.04 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added, and 15 ° C. was added at 15 ° C. After aging for 30 minutes, the temperature was raised to 40 ° C., and 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 40 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Example 2)
Polymerization was carried out in the same manner as in Example 1 except that the aging time was 30 minutes. The polymerization results are shown in Tables 1 and 2.

(Example 3)
Polymerization was carried out in the same manner as in Example 1 except that the aging time was 60 minutes. The polymerization results are shown in Tables 1 and 2.

Example 4
Polymerization was carried out in the same manner as in Example 1 except that the aging time was 120 minutes. The polymerization results are shown in Tables 1 and 2.

(Example 5)
Polymerization was carried out in the same manner as in Example 1 except that the aging time was 240 minutes. The polymerization results are shown in Tables 1 and 2.

(Example 6)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Then, hydrogen gas 0.04 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, the temperature was raised to 40 ° C., and 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added. After aging at 40 ° C. for 15 minutes, 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 40 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Example 7)
Polymerization was carried out in the same manner as in Example 1 except that the aging time was 30 minutes. The polymerization results are shown in Tables 1 and 2.

(Example 8)
Polymerization was carried out in the same manner as in Example 1 except that the aging time was 60 minutes. The polymerization results are shown in Tables 1 and 2.

Example 9
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Then, hydrogen gas 0.04 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, the temperature was lowered to 20 ° C., and 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added. After aging at 20 ° C. for 60 minutes, the temperature was raised to 40 ° C., and 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 40 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Example 10)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Next, hydrogen gas 0.07 MPa / cm ² was added. After the temperature of the solution was adjusted to 30 ° C., 1.5 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added and stirred for 3 minutes at 500 rpm. Next, 0.6 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added, and the mixture was stirred at 30 ° C. for 30 minutes. After aging for 1 minute, 0.14 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 30 ° C. for 30 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Example 11)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Next, hydrogen gas 0.07 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, the temperature was raised to 40 ° C., and 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added. Aged at 40 ° C. for 60 minutes. Next, the temperature was lowered to 30 ° C., and 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 30 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

Example 12
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 460 ml of toluene and 140 ml of butadiene was charged. Next, hydrogen gas 0.07 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, the temperature was raised to 40 ° C., and 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added. Aged at 40 ° C. for 60 minutes. Next, the temperature was lowered to 30 ° C., and 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 30 ° C. for 20 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Example 13)
Polymerization was carried out in the same manner as in Example 12 except that toluene was changed to 390 ml and butadiene 210 ml. The polymerization results are shown in Tables 1 and 2.

(Example 14)
Polymerization was carried out in the same manner as in Example 12 except that 350 ml of toluene and 250 ml of butadiene were used. The polymerization results are shown in Tables 1 and 2.

(Example 15)
Polymerization was carried out in the same manner as in Example 12 except that 300 ml of toluene and 300 ml of butadiene were used. The polymerization results are shown in Tables 1 and 2.

(Example 16)
Polymerization was carried out in the same manner as in Example 12 except that 250 ml of toluene and 350 ml of butadiene were used. The polymerization results are shown in Tables 1 and 2.

(Example 17)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 460 ml of toluene and 140 ml of butadiene was charged. Next, hydrogen gas 0.07 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, the temperature was raised to 40 ° C., and 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added. Aged at 40 ° C. for 60 minutes. Next, 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 40 ° C. for 15 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Example 18)
Polymerization was carried out in the same manner as in Example 17 except that toluene was changed to 390 ml and butadiene 210 ml. The polymerization results are shown in Tables 1 and 2.

(Example 19)
Polymerization was carried out in the same manner as in Example 17 except that 350 ml of toluene and 250 ml of butadiene were used. The polymerization results are shown in Tables 1 and 2.

(Example 20)
Polymerization was carried out in the same manner as in Example 17 except that 300 ml of toluene and 300 ml of butadiene were used. The polymerization results are shown in Tables 1 and 2.

(Example 21)
Polymerization was carried out in the same manner as in Example 17 except that 250 ml of toluene and 350 ml of butadiene were used. The polymerization results are shown in Tables 1 and 2.

(Comparative Example 1)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Then, hydrogen gas 0.04 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added and immediately heated to 40 ° C. Warm, 0.11 ml of a toluene solution of triphenylcarbenium tetrakis (pentafluorophenyl) borate (0.43 mol / L) was added. After polymerization at 40 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Comparative Example 2)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Next, after the temperature of the solution was adjusted to 30 ° C., 1.5 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added and stirred for 3 minutes at 500 rpm. Next, 0.6 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added, and the mixture was kept at 30 ° C. for 2 minutes. After aging, the temperature was raised to 40 ° C., and 0.14 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 40 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

(Comparative Example 3)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Next, after the temperature of the solution was adjusted to 30 ° C., 1.5 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added and stirred for 3 minutes at 500 rpm. Next, 0.6 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added, and the mixture was kept at 30 ° C. for 2 minutes. Aged. Next, 0.14 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added, polymerized at 30 ° C. for 25 minutes, and then 3 ml of an ethanol solution containing an antioxidant was added. The polymerization was stopped. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.
(Comparative Example 4)
The inside of the autoclave having an internal volume of 1.5 L was purged with nitrogen, and a solution consisting of 390 ml of toluene and 210 ml of butadiene was charged. Then, hydrogen gas 0.04 MPa / cm ² was added. After setting the temperature of the solution to 30 ° C., 1.2 ml of a cyclohexane solution (2 mol / L) of triethylaluminum (TEA) was added, and the mixture was stirred at 500 rpm for 3 minutes. Next, the temperature was raised to 40 ° C., and 0.48 ml of a toluene solution (0.05 mol / L) of yttrium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedioate) was added. After aging at 40 ° C. for 3 minutes, 0.11 ml of a toluene solution (0.43 mol / L) of triphenylcarbenium tetrakis (pentafluorophenyl) borate was added. After polymerization at 40 ° C. for 25 minutes, 3 ml of an ethanol solution containing an antioxidant was added to stop the polymerization. After releasing the pressure inside the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. The recovered polybutadiene was then vacuum dried at 80 ° C. for 3 hours. The polymerization results are shown in Tables 1 and 2.

Claims (4)

In the process for producing a catalyst for conjugated diene polymerization comprising (A) an yttrium compound, (B) an ionic compound comprising a non-coordinating anion and a cation, and (C) an organoaluminum compound, A method for producing a catalyst for conjugated diene polymerization, comprising mixing components C) and aging at less than 50 ° C. for 5 to 300 minutes, and then adding component (B). The method for producing a conjugated diene polymerization catalyst according to claim 1, wherein the yttrium compound is an yttrium compound represented by the following general formula (1).

(R ₁ , R ₂ and R ₃ represent hydrogen or a substituent having 1 to 12 carbon atoms, O represents an oxygen atom, and Y represents an yttrium atom) A catalyst for conjugated diene polymerization obtained by the method according to claim 1 or 2. A method for producing a conjugated diene polymer, wherein the catalyst for conjugated diene polymerization according to claim 3 is used.