JPH072927A - Production of butadiene polymer - Google Patents

Abstract

PURPOSE:To provide a production process which uses a specific catalyst system and by which a butadiene polymer with a high vinyl bond content is obtd., the polymn. proceeds at a high activity even in a hydrocarbon solvent, and the mol.wt. and m.p. of the polymer are easily controlled. CONSTITUTION:Polymn. is carried out in the presence of a surfactant in a process for producing polybutadiene by polymerizing a conjugated diene component contg. at least 50mol% 1,3-butadiene in the presence or absence of an inert solvent and in the presence of a catalyst system comprising a cobalt compd., an organoaluminum compd. represented by R<1>3Al (wherein R<1> is alkyl, aryl, or aralkyl), water, a phosphine compd., and at least one compd. selected from the group consisting of a halogen-contg. organoaluminum compd. represented by R<2>AlX3-n (wherein R<2> is alkyl, aryl, or aralkyl; X is F, Cl, Br, or I; and n is 0, 1, 1.5, or 2) and an active halogen compd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a butadiene-based polymer, and more particularly to a novel catalyst system having a high vinyl bond content and capable of controlling the melting point of the resulting crystalline polymer. And a method for producing a butadiene-based polymer using the same.

[0002]

2. Description of the Related Art The structure of a butadiene-based polymer containing 1,3-butadiene as a main component largely depends on the catalyst system.
For example, it is known that cis or trans 1,4-polybutadiene can be obtained with a catalyst system composed of a transition metal compound and alkylaluminum. Also, CoB
From the catalyst system consisting of r ₂ (PPh ₃ ) ₂ , trialkylaluminum and water, syndiotactic 1,2-
It is known that polybutadiene can be obtained [JP-B-44-32425]. Also known is a method for producing crystalline 1,2-polybutadiene having a controlled molecular weight, which uses an active halogen compound or a halogen-containing organoaluminum compound as a molecular weight modifier for the above catalyst system [Japanese Patent Publication No. 61-29362]. No. 29363]. However, this catalyst system is highly active in a halogenated hydrocarbon solvent represented by methylene chloride, but its polymerization activity is significantly reduced in a general-purpose hydrocarbon solvent, and the melting point and molecular weight of the resulting polymer are not sufficient. There is a problem that there is no.

On the other hand, BuLi or Cr (aca
c) It is known that atactic and isotactic 1,2-polybutadiene can be obtained from a catalyst system consisting of _3- Al (C ₂ H ₅ ) ₃ respectively [AF Hala
sa et al., J. Polym. Sci. Polym. Chem. Ed., 19, 1357 (1
981); G. Natta et al., Chem. Ind. (Millan), 41, 1163 (19).
59)]. In the case of industrial production, this catalyst system has a problem in catalytic activity and is not practical.

[0004]

The present invention has been made against the background of the above-mentioned problems of the prior art. By preparing a specific catalyst system, polymerization can be carried out with high activity even in a hydrocarbon solvent to obtain a heavy polymer. It is an object of the present invention to provide a method for producing a butadiene-based polymer, which has a high vinyl bond content, is crystalline, and can control the crystallinity (melting point) of the polymer.

[0005]

Means for Solving the Problems The present invention is a conjugated diene containing 1,3-butadiene at least 50 mol% or more, (A) a cobalt compound, (B) an organoaluminum represented by the general formula R ¹ ₃ Al Compound (R ¹ is an alkyl group,
Aryl group and aralkyl group are shown), (C) water, (D)
Phosphine compound and (E) general formula R ² _n AlX _3-n
A halogen-containing organoaluminum compound represented by (R ² is an alkyl group, an aryl group, an aralkyl group, X is fluorine,
Halogen atoms of chlorine, bromine and iodine, n is 0, 1, 1.
5, 2)), or (F) using a catalyst composed of at least one compound selected from active halogen compounds, in producing polybutadiene in the presence or absence of an inert solvent, (G) interface It is intended to provide a method for producing a butadiene polymer, which is characterized by polymerizing in the presence of an activator.

As the conjugated diene other than 1,3-butadiene used in the present invention, 1,3-pentadiene, 1,3-butadiene derivative substituted with a higher alkyl group, 2
-Alkyl-substituted-1,3-butadiene and the like. Among these, 1,3-butadiene derivatives substituted with higher alkyl groups include 1-pentyl-1,3-butadiene, 1-hexyl-1,3-butadiene, 1-heptyl-1,3-butadiene, 1 -Octyl-1,3-butadiene and the like.

Typical examples of 2-alkyl-substituted-1,3-butadiene include 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene,
2-propyl-1,3-butadiene, 2-isopropyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-isobutyl-1,3-butadiene, 2-amyl-1,3-butadiene, 2-isoamyl-1,3-butadiene, 2-hexyl-1,3-butadiene, 2-cyclohexyl-1,3-butadiene, 2-isohexyl-
1,3-butadiene, 2-heptyl-1,3-butadiene, 2-isoheptyl-1,3-butadiene, 2-octyl-1,3-butadiene, 2-isooctyl-1,3
-Butadiene and the like. Among these conjugated dienes, isoprene and 1,3-pentadiene are preferable as the conjugated diene used as a mixture with 1,3-butadiene. The content of 1,3-butadiene in the monomer component used for the polymerization is 50 mol% or more, preferably 70 mol% or more, and when it is less than 50 mol%, the vinyl bond content in the butadiene-based polymer is controlled. Is difficult and not preferable.

Examples of the cobalt compound as the component (A) used in the present invention include cobalt compounds containing an organic group. Specifically, there are organic acid salts and complexes of cobalt. The organic acid salt of cobalt is preferably an organic acid salt of cobalt having 4 or more carbon atoms from the viewpoint of solubility in an organic solvent. Specific organic acid salts include butyric acid salts, hexanoic acid salts, heptyl acid salts, octyl acid salts such as 2-ethylhexyl acid, decanoic acid salts and stearic acid, oleic acid, higher fatty acid salts such as erucic acid, Examples thereof include benzoate, tolylate, xylylate, ethyl benzoate and other alkyls, aralkyls, allyl-substituted benzoates and naphthoates, alkyl, aralkyl- or allyl-substituted naphthoates. Of these, so-called octylates of 2-ethylhexyl acid, stearates, and benzoates are preferable because of their excellent solubility in organic solvents.

Cobalt complexes include nitrogen-containing compounds such as acetylacetone, acetoacetate phosphine, carbonyl, isonitrile and pyridine as ligands, salicylaldehyde, dioximes, vinyl compounds, cyclopentadienyl, π-allyl compounds, and The compound which these derivatives coordinated can be mentioned. Specifically, cobalt chloride, cobalt bromide, cobalt iodide, and other cobalt halide pyridine complexes, trisacetylacetonato cobalt, cobalt acetocomplex ester complexes, cobalt carbonyl, cobalt bistriphenylphosphine dichloride, cobalt bistriphenylphosphine. Examples thereof include dipromide, cobalt tristriphenylphosphine chloride, cobalt tristriphenylphosphine bromide and π-cyclooctenyl-π-1,5-cyclooctadiene cobalt. Of these cobalt compounds, organic acid salts, acetylacetone complexes, pyridine complexes, and phosphine complexes are preferable in view of polymerization activity and control of molecular characteristics because they are excellently soluble in a polymerization solvent.

The component (B) used in the present invention, R ₃ Al
Examples of the organoaluminum compound component represented by (R is an alkyl or aryl group) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, and tri-n-octyl. Examples thereof include aluminum, triarylaluminum such as tridodecylaluminum and triphenylaluminum, trialkylaluminum and the like. Among these organoaluminum compounds, trialkylaluminum is preferable from the viewpoint of polymerization activity and control of molecular characteristics.

In the catalyst of the present invention, the phosphine compound as the component (D) is an essential component for activation of the polymerization catalyst, control of vinyl bond structure and crystallinity, and is represented by the general formula (I). It is an organic phosphorus compound.

[0012]

[Chemical 1]

The carbon number of R ¹ , R ² and R ³ is not particularly limited, but is preferably 1-6. Examples of the (D) phosphine compound include tri- (3-methylphenyl) phosphine, tri- (3-ethylphenyl) phosphine, tri- (3,5-dimethylphenyl) phosphine, tri-
(3,4-dimethylphenyl) phosphine, tri- (3
-Isopropylphenyl) phosphine, tri- (3-t
-Butylphenyl) phosphine, tri- (3,5-diethylphenyl) formine, tri- (3-methyl-5-
Ethylphenyl) phosphine, tri- (3-phenylphenyl) phosphine, tri- (3,4,5-trimethylphenyl) phosphine, tri- (4-methoxy-3,5
-Dimethylphenyl) phosphine, tri- (4-ethoxy-3,5-diethylphenyl) phosphine, tri-
(4-Butoxy-3,5-dibutylphenyl) phosphine, tri (p-methoxyphenylphosphine), tricyclohexylphosphine, dicyclohexylphenylphosphine, tribenzylphosphine, tri (4-methylphenylphosphine), tri (4-ethylphenyl) Phosphine), tri (4-chlorophenyl) phosphine and the like can be used. Of these, particularly preferred are triphenylphosphine, tri- (3-methylphenyl) phosphine, tri- (4-methoxy-).
3,5-dimethylphenyl) phosphine and the like can be mentioned.

R ² _n A of the component (E) used in the present invention
halogen-containing organoaluminum compound represented by 1X _3-n (R ² is an alkyl group, an aryl group, an aralkyl group, X is a halogen atom of fluorine, chlorine, bromine, iodine, n is 0,
1, 1.5, and 2)), dimethyl aluminum chloride, dimethyl aluminum sesquichloride, methyl aluminum dichloride, diethyl aluminum chloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride, di-n-propyl aluminum chloride, di-n. -Butyl aluminum chloride, diisobutyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide.

The active halogen compound of the component (F) used in the present invention is a compound having a halogen bonded to a tertiary carbon, a compound having a halogen bonded to an allyl group, a compound having a halogen bonded to a benzyl group, an aromatic compound. Means a compound in which halogen is bound to a cationic compound having. The carbocation free of halogen is a stable compound. Specific examples thereof include t-butyl halide, t-amyl halide, allyl halide, crotyl halide, benzyl halide, methylbenzyl halide, chlorobenzyl halide, triphenylmethyl halide and tropium halide. Examples of the halogen atom of the above compound include fluorine, chlorine, bromine and iodine.

Examples of the surfactant (G) used in the present invention include alkylbenzene sulfonic acids such as dodecylbenzene sulfonic acid, diisopropylnaphthalene sulfonic acid, butylnaphthalene sulfonic acid and diisobutylnaphthalene sulfonic acid. Formalin condensate of naphthalene sulfonic acid, dialkyl sulfosuccinic acid ester, alkyl sulfoacetic acid, α-olefin sulfonic acid, N-acyl taurine and other sulfonates represented by sodium, potassium and calcium salts, sulfated oil, higher alcohols Anionic surfactants such as sulfate ester salts, sulfate ester salts represented by secondary higher alcohol sulfate esters such as sodium, potassium and calcium salts, stearyl dimethylbenzyl ammonium chloride , Quaternary aliphatic ammonium salts such as distearyldimethylammonium chloride, dilauryldimethylammonium chloride, didecyldimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride and distearyldimethylammonium chloride, benzalkonium chloride, There may be mentioned cationic surfactants such as pyridinium salts.

The amount of the catalyst used in the present invention is 0.001 to 1 mmol, preferably 0.01 to 0, in terms of cobalt atom, of the cobalt compound as the component (A) per mol of the conjugated diene. It is about 0.5 mmol.
The amount of the organoaluminum compound as the component (B) used is usually 1 to 1000, preferably 5 to 500, as the ratio of aluminum atom to cobalt atom of the component (A), Al / Co ratio. The amount of water used as the component (C) is usually 0.1 to 2.0 as H ₂ O / Al, which is an equivalent ratio of water to aluminum atoms of the organic aluminum used as the components (B) and (E). Preferably 0.25
It is 1.50 mol. Further, the amount of the phosphine compound used as the component (D) is usually 0.1 to 1 as the ratio of phosphorus atom to cobalt atom of the component (A), P / Co ratio.
It is 0, preferably 0.3 to 5. The amount of the halogen-containing organoaluminum used as the component (E) is 0.03 to 30 in terms of a molar ratio with the organoaluminum used as the component (B) and an organoaluminum / halogen-containing organoaluminum ratio. The amount of the active halogen compound used as the component (F) is generally 1 to 1 in terms of the molar ratio to the organoaluminum used as the component (B) and the organic aluminum / active halogen compound ratio.
It is 300, preferably 3 to 100. The amount of the component (G) surfactant used is the equivalent ratio of the component (A) to the cobalt atom of the component (surfactant / Co), and is usually 0.01 to 10, preferably 0. 1 to 5.

The catalyst used in the present invention is not particularly limited in the order of addition of the respective catalyst components, but the component (C) water and the component (G) are used.
After the component surfactants are added in a sequential order, (B)
A method for preparing a catalyst in which the component and the aluminum or active halide of the component (E) or (F) are added and mixed with the cobalt compound of the component (A) is preferable. The catalyst may be prepared by mixing the respective components in advance before contacting it with the conjugated diene containing 1,3-butadiene as the main component of the present invention. It can also be prepared by mixing the respective components in the presence of.

In the present invention, the conjugated diene containing 1,3-butadiene as the main component is added to the catalyst, that is, (A) to (G).
Polymerization is carried out in an inert organic solvent using a catalyst containing the component as the main component. Examples of the inert organic solvent used as a polymerization solvent include aromatic hydrocarbon solvents such as benzene, toluene, xylene and cumene, aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-butane, and cyclopentane. Alicyclic hydrocarbon solvents such as methylcyclopentane and cyclohexane, halogenated carbonization such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, perchlorethylene, chlorobenzene, prombenzene and chlorotoluene Hydrogen solvent,
And mixtures thereof.

The polymerization temperature is usually -50 to 120 ° C,
It is preferably -20 to 100 ° C. The polymerization reaction may be a batch system or a continuous system. The monomer concentration in the catalyst is
Usually, it is 5 to 50% by weight, preferably 10 to 35% by weight. Further, in order to produce a polymer, in order not to deactivate the catalyst of the present invention and the polymer, consideration should be given so as to minimize mixing of a compound having a deactivating action such as oxygen, water or carbon dioxide gas into the polymerization system. is necessary. When the polymerization reaction proceeds to a desired stage, the reaction mixture is added with alcohol, another polymerization terminator, an antioxidant, an antioxidant, an ultraviolet absorber, etc., and then the produced polymer is separated and washed according to a usual method. The desired butadiene-based polymer can be obtained by drying.

The butadiene-based polymer obtained by the production method of the present invention has a vinyl bond content of 7 in the butadiene portion.
It is 0% or more, preferably 70 to 99%, more preferably 80 to 95%. The butadiene-based polymer obtained by the present invention has crystallinity and its melting point is 40 to
The temperature is 150 ° C, preferably 60 to 130 ° C. The molecular weight of the butadiene-based polymer obtained in the present invention can be varied over a wide range, but its polystyrene-equivalent number average molecular weight is usually 5,000 to 1.0.
0,000, preferably 10,000 to 800,000
It is 0, and if less than 5,000, it is not preferable because it is inferior in strength properties. On the other hand, if it exceeds 1,000,000, it is inferior in processability, and excessive torque is applied during kneading with a roll or Banbury, or it is compounded. Dispersion of chemicals and reinforcing agents such as carbon black will be poor, and problems such as poor performance of the vulcanizate will occur, which is not preferable.

The butadiene-based polymer obtained in the present invention has a molecular weight distribution (M) represented by the ratio of polystyrene-equivalent number average molecular weight (Mn) and weight average molecular weight (Mw).
w / Mn) can be varied over a wide range, but it is usually from 1.5 to 5.0, and less than 1.5 is technically difficult, while when it exceeds 5.0, the physical properties are poor. ,
In addition, the low molecular weight increases, which is not preferable.

The butadiene-based polymer obtained according to the present invention is blended as a raw rubber with the polymer alone or blended with other synthetic rubber or natural rubber, and if necessary, oil-extended with a process oil, and then, A rubber composition that is prepared by adding a filler such as carbon black, a vulcanizing agent, and a usual vulcanizing compounding agent such as a vulcanization accelerator into a rubber composition, and vulcanizing the composition to obtain mechanical properties and abrasion resistance. It can be used for applications such as tires, hoses, belts, and various other industrial products.

[0024]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the examples, parts and% are based on weight unless otherwise specified.
Further, various measurements in the examples were based on the following methods.
The vinyl bond content of the butadiene-based polymer was determined by an infrared absorption spectrum method (Morero method). The melting point of the butadiene-based polymer is determined by using a DSC (differential scanning calorimeter)
It measured according to TMD3418. The weight average molecular weight and the number molecular weight were measured by gel permeation chromatography (GPC) [C-4A manufactured by Shimadzu Corporation] at 40 ° C. using tetrahydrofuran as a solvent.

Examples 1 to 9 40 g of toluene and 1,3-butadiene (BD) in a pressure-resistant bottle made of hard glass having an internal volume of 100 ml under a dry nitrogen atmosphere.
10 g, potassium dodecylbenzene sulfonate and calcium dodecylbenzene sulfonate shown in Table 1, respectively.
16 mg of water and a predetermined amount of a toluene solution of stearyldimethylbenzylammonium chloride and distearyldimethylammonium chloride were added, and the mixture was cooled to 10 ° C. Furthermore, a predetermined amount of a toluene solution of mixed organic aluminum (Al) of triethylaluminum and ethylaluminum sesquicycloid was added, and the organic aluminum component was modified for 30 minutes. Subsequently, a predetermined amount of cobalt octylate (C
A toluene solution of a mixture of o) and triphenylphosphine (P) was added to carry out a polymerization reaction at 10 ° C. for 30 minutes. The catalyst concentration and composition used were BD / Co (molar ratio).
= 15000, Al / Co (atomic ratio) = 100, Et ₃
Al / Et _1.5 AlCl _1.5 (molar ratio) = 90/10,
H ₂ O / Al (equivalent ratio) = 0.7, P / Co (atomic ratio)
= 2.5. The reaction was stopped by adding a small amount of methanol containing 2,6-di-t-butyl-p-cresol as a terminating agent to the reaction system. Then, the reaction solution is poured into a large amount of methanol to precipitate a polymer,
Solidified. Further, it was vacuum dried at 40 ° C., the yield was measured, and the polymer yield was determined. 1,2-Vinyl bond content (%), melting point (° C), weight average molecular weight (M
w), number average molecular weight (Mn), molecular weight distribution (Mw / M
n) was measured. The results are shown in Table 1.

[0026]

[Table 1]

Comparative Example 1 The same operation as in Example 1 was carried out except that the surfactant was not used in Example 1. The results are shown in Table 1.

Examples 10 to 14 and Comparative Example 2 As in Example 1, except that the halogen-containing organoaluminum used in Example 1 was changed from ethylaluminum sesquichloride to diethylaluminum chloride in a predetermined composition ratio. The same operation was performed to obtain a butadiene-based polymer. In addition, Comparative Example 2 is one in which the surfactant is not added in Example 2. The results are shown in Table 1.

Examples 15 to 17 40 g of toluene and 1,3-butadiene (BD) in a pressure-resistant bottle made of hard glass having an internal volume of 100 ml under a dry nitrogen atmosphere.
10 g of each of the dodecylbenzenesulfonate shown in Table 1, a predetermined amount of a toluene solution of stearyldimethylbenzylammonium chloride and distearyldimethylammonium chloride, and 16 mg of water were added, and the mixture was cooled to 10 ° C. Further, a predetermined amount of a toluene solution of triethylaluminum and then a toluene solution of benzyl chloride (R ³ X) were added, and the mixture was aged for 2 hours. Then, a predetermined amount of cobalt octylate (Co) and triphenylphosphine (P)
A toluene solution of the mixture was added and a polymerization reaction was carried out at 10 ° C. for 30 minutes. The catalyst concentration and composition used are BD
/ Co (molar ratio) = 15000, Al / Co (atomic ratio)
_{= 100, Et 3 Al / R} 3 X ( atomic ratio) = 10, H ₂
O / Al (equivalent ratio) = 0.7, P / Co (atomic ratio) =
It is 2.5. To stop the reaction, use 2,6-di-
It was carried out by adding a small amount of methanol containing t-butyl-p-cresol to the reaction system. Then, the reaction solution was poured into a large amount of methanol to precipitate and coagulate the polymer. Further vacuum drying at 40 ℃, measure the yield,
The polymer yield was determined. 1,2-Vinyl bond content (%), melting point (° C), weight average molecular weight (M
w), number average molecular weight (Mn), molecular weight distribution (Mw / M
n) was measured. The results are shown in Table 1.

Comparative Example 3 The same operation as in Example 3 was carried out except that the surfactant was not used in Example 3. The results are shown in Table 1.

[0031]

According to the method for producing a butadiene-based polymer of the present invention, by employing a specific catalyst system, it has a highly active polymerization ability in various organic solvents, and the obtained polymer is also a high vinyl compound. It is the bond content, and it is possible to control the crystallinity, in other words, the melting point.

Claims (1)

[Claims] 1. A 1,3-conjugated diene containing at least 50 mol% of butadiene, (A) a cobalt compound, (B) the general formula R ¹ organoaluminum compound represented by the ₃ Al (R ¹ is an alkyl group, An aryl group, an aralkyl group), (C) water, (D) a phosphine compound and (E) a halogen-containing organoaluminum compound represented by the general formula R ² _n AlX _3-n (R ² is an alkyl group, an aryl group, An aralkyl group, X is a halogen atom of fluorine, chlorine, bromine or iodine, n is 0, 1, 1.5 or 2), or (F) at least 1 selected from active halogen compounds.
When producing polybutadiene in the presence or absence of an inert solvent using a catalyst composed of one or more compounds, a method for producing a butadiene polymer is characterized by polymerizing in the presence of (G) a surfactant. .